Evaluation of a smartphone human activity recognition application with able-bodied and stroke participants.

PubMed

Capela, N A; Lemaire, E D; Baddour, N; Rudolf, M; Goljar, N; Burger, H

2016-01-20

Mobile health monitoring using wearable sensors is a growing area of interest. As the world's population ages and locomotor capabilities decrease, the ability to report on a person's mobility activities outside a hospital setting becomes a valuable tool for clinical decision-making and evaluating healthcare interventions. Smartphones are omnipresent in society and offer convenient and suitable sensors for mobility monitoring applications. To enhance our understanding of human activity recognition (HAR) system performance for able-bodied and populations with gait deviations, this research evaluated a custom smartphone-based HAR classifier on fifteen able-bodied participants and fifteen participants who suffered a stroke. Participants performed a consecutive series of mobility tasks and daily living activities while wearing a BlackBerry Z10 smartphone on their waist to collect accelerometer and gyroscope data. Five features were derived from the sensor data and used to classify participant activities (decision tree). Sensitivity, specificity and F-scores were calculated to evaluate HAR classifier performance. The classifier performed well for both populations when differentiating mobile from immobile states (F-score > 94 %). As activity recognition complexity increased, HAR system sensitivity and specificity decreased for the stroke population, particularly when using information derived from participant posture to make classification decisions. Human activity recognition using a smartphone based system can be accomplished for both able-bodied and stroke populations; however, an increase in activity classification complexity leads to a decrease in HAR performance with a stroke population. The study results can be used to guide smartphone HAR system development for populations with differing movement characteristics.

Inertial Sensor Measurements of Upper-Limb Kinematics in Stroke Patients in Clinic and Home Environment.

PubMed

Held, Jeremia P O; Klaassen, Bart; Eenhoorn, Albert; van Beijnum, Bert-Jan F; Buurke, Jaap H; Veltink, Peter H; Luft, Andreas R

2018-01-01

Upper-limb impairments in stroke patients are usually measured in clinical setting using standard clinical assessment. In addition, kinematic analysis using opto-electronic systems has been used in the laboratory setting to map arm recovery. Such kinematic measurements cannot capture the actual function of the upper extremity in daily life. The aim of this study is to longitudinally explore the complementarity of post-stroke upper-limb recovery measured by standard clinical assessments and daily-life recorded kinematics. The study was designed as an observational, single-group study to evaluate rehabilitation progress in a clinical and home environment, with a full-body sensor system in stroke patients. Kinematic data were recorded with a full-body motion capture suit during clinical assessment and self-directed activities of daily living. The measurements were performed at three time points for 3 h: (1) 2 weeks before discharge of the rehabilitation clinic, (2) right after discharge, and (3) 4 weeks after discharge. The kinematic analysis of reaching movements uses the position and orientation of each body segment to derive the joint angles. Newly developed metrics for classifying activity and quality of upper extremity movement were applied. The data of four stroke patients (three mildly impaired, one sever impaired) were included in this study. The arm motor function assessment improved during the inpatient rehabilitation, but declined in the first 4 weeks after discharge. A change in the data (kinematics and new metrics) from the daily-life recording was seen in in all patients. Despite this worsening patients increased the number of reaches they performed during daily life in their home environment. It is feasible to measure arm kinematics using Inertial Measurement Unit sensors during daily life in stroke patients at the different stages of rehabilitation. Our results from the daily-life recordings complemented the data from the clinical assessments and illustrate the potential to identify stroke patient characteristics, based on kinematics, reaching counts, and work area. https://clinicaltrials.gov, identifier NCT02118363.

Mobile Functional Reach Test in People Who Suffer Stroke: A Pilot Study

PubMed Central

Merchán-Baeza, Jose Antonio; González-Sánchez, Manuel

2015-01-01

Background Postural instability is one of the major complications found in people who survive a stroke. Parameterizing the Functional Reach Test (FRT) could be useful in clinical practice and basic research, as this test is a clinically accepted tool (for its simplicity, reliability, economy, and portability) to measure the semistatic balance of a subject. Objective The aim of this study is to analyze the reliability in the FRT parameterization using inertial sensor within mobile phones (mobile sensors) for recording kinematic variables in patients who have suffered a stroke. Our hypothesis is that the sensors in mobile phones will be reliable instruments for kinematic study of the FRT. Methods This is a cross-sectional study of 7 subjects over 65 years of age who suffered a stroke. During the execution of FRT, the subjects carried two mobile phones: one placed in the lumbar region and the other one on the trunk. After analyzing the data obtained in the kinematic registration by the mobile sensors, a number of direct and indirect variables were obtained. The variables extracted directly from FRT through the mobile sensors were distance, maximum angular lumbosacral/thoracic displacement, time for maximum angular lumbosacral/thoracic displacement, time of return to the initial position, and total time. Using these data, we calculated speed and acceleration of each. A descriptive analysis of all kinematic outcomes recorded by the two mobile sensors (trunk and lumbar) was developed and the average range achieved in the FRT. Reliability measures were calculated by analyzing the internal consistency of the measures with 95% confidence interval of each outcome variable. We calculated the reliability of mobile sensors in the measurement of the kinematic variables during the execution of the FRT. Results The values in the FRT obtained in this study (2.49 cm, SD 13.15) are similar to those found in other studies with this population and with the same age range. Intrasubject reliability values observed in the use of mobile phones are all located above 0.831, ranging from 0.831 (time B_C trunk area) and 0.894 (displacement A_B trunk area). Likewise, the observed intersubject values range from 0.835 (time B_C trunk area) and 0.882 (displacement A_C trunk area). On the other hand, the reliability of the FRT was 0.989 (0.981-0.996) and 0.978 (0.970-0.985), intrasubject and intersubject respectively. Conclusions We found that mobile sensors in mobile phones could be reliable tools in the parameterization of the Functional Reach Test in people who have had a stroke. PMID:28582239

Variables influencing wearable sensor outcome estimates in individuals with stroke and incomplete spinal cord injury: a pilot investigation validating two research grade sensors.

PubMed

Jayaraman, Chandrasekaran; Mummidisetty, Chaithanya Krishna; Mannix-Slobig, Alannah; McGee Koch, Lori; Jayaraman, Arun

2018-03-13

Monitoring physical activity and leveraging wearable sensor technologies to facilitate active living in individuals with neurological impairment has been shown to yield benefits in terms of health and quality of living. In this context, accurate measurement of physical activity estimates from these sensors are vital. However, wearable sensor manufacturers generally only provide standard proprietary algorithms based off of healthy individuals to estimate physical activity metrics which may lead to inaccurate estimates in population with neurological impairment like stroke and incomplete spinal cord injury (iSCI). The main objective of this cross-sectional investigation was to evaluate the validity of physical activity estimates provided by standard proprietary algorithms for individuals with stroke and iSCI. Two research grade wearable sensors used in clinical settings were chosen and the outcome metrics estimated using standard proprietary algorithms were validated against designated golden standard measures (Cosmed K4B2 for energy expenditure and metabolic equivalent and manual tallying for step counts). The influence of sensor location, sensor type and activity characteristics were also studied. 28 participants (Healthy (n = 10); incomplete SCI (n = 8); stroke (n = 10)) performed a spectrum of activities in a laboratory setting using two wearable sensors (ActiGraph and Metria-IH1) at different body locations. Manufacturer provided standard proprietary algorithms estimated the step count, energy expenditure (EE) and metabolic equivalent (MET). These estimates were compared with the estimates from gold standard measures. For verifying validity, a series of Kruskal Wallis ANOVA tests (Games-Howell multiple comparison for post-hoc analyses) were conducted to compare the mean rank and absolute agreement of outcome metrics estimated by each of the devices in comparison with the designated gold standard measurements. The sensor type, sensor location, activity characteristics and the population specific condition influences the validity of estimation of physical activity metrics using standard proprietary algorithms. Implementing population specific customized algorithms accounting for the influences of sensor location, type and activity characteristics for estimating physical activity metrics in individuals with stroke and iSCI could be beneficial.

Lightning Reporting at 45th Weather Squadron: Recent Improvements

NASA Technical Reports Server (NTRS)

Finn, Frank C.; Roeder, William P.; Buchanan, Michael D.; McNamara, Todd M.; McAllenan, Michael; Winters, Katherine A.; Fitzpatrick, Michael E.; Huddleston, Lisa L.

2010-01-01

The 45th Weather Squadron (45 WS) provides daily lightning reports to space launch customers at CCAFS/KSC. These reports are provided to assess the need to inspect the electronics of satellite payloads, space launch vehicles, and ground support equipment for induced current damage from nearby lightning strokes. The 45 WS has made several improvements to the lightning reports during 2008-2009. The 4DLSS, implemented in April 2008, provides all lightning strokes as opposed to just one stroke per flash as done by the previous system. The 45 WS discovered that the peak current was being truncated to the nearest kilo amp in the database used to generate the daily lightning reports, which led to an up to 4% underestimate in the peak current for average lightning. This error was corrected and led to elimination of this underestimate. The 45 WS and their mission partners developed lightning location error ellipses for 99% and 95% location accuracies tailored to each individual stroke and began providing them in the spring of 2009. The new procedure provides the distance from the point of interest to the best location of the stroke (the center of the error ellipse) and the distance to the closest edge of the ellipse. This information is now included in the lightning reports, along with the peak current of the stroke. The initial method of calculating the error ellipses could only be used during normal duty hours, i.e. not during nights, weekends, or holidays. This method was improved later to provide lightning reports in near real-time, 24/7. The calculation of the distance to the closest point on the ellipse was also significantly improved later. Other improvements were also implemented. A new method to calculate the probability of any nearby lightning stroke. being within any radius of any point of interest was developed and is being implemented. This may supersede the use of location error ellipses. The 45 WS is pursuing adding data from nine NLDN sensors into 4DLSS in real-time. This will overcome the problem of 4DLSS missing some of the strong local strokes. This will also improve the location accuracy, reduce the size and eccentricity of the location error ellipses, and reduce the probability of nearby strokes being inside the areas of interest when few of the 4DLSS sensors are used in the stroke solution. This will not reduce 4DLSS performance when most of the 4DLSS sensors are used in the stroke solution. Finally, several possible future improvements were discussed, especially for improving the peak current estimate and the error estimate for peak current, and upgrading the 4DLSS. Some possible approaches for both of these goals were discussed.

Assessing Walking Strategies Using Insole Pressure Sensors for Stroke Survivors.

PubMed

Munoz-Organero, Mario; Parker, Jack; Powell, Lauren; Mawson, Susan

2016-10-01

Insole pressure sensors capture the different forces exercised over the different parts of the sole when performing tasks standing up such as walking. Using data analysis and machine learning techniques, common patterns and strategies from different users to achieve different tasks can be automatically extracted. In this paper, we present the results obtained for the automatic detection of different strategies used by stroke survivors when walking as integrated into an Information Communication Technology (ICT) enhanced Personalised Self-Management Rehabilitation System (PSMrS) for stroke rehabilitation. Fourteen stroke survivors and 10 healthy controls have participated in the experiment by walking six times a distance from chair to chair of approximately 10 m long. The Rivermead Mobility Index was used to assess the functional ability of each individual in the stroke survivor group. Several walking strategies are studied based on data gathered from insole pressure sensors and patterns found in stroke survivor patients are compared with average patterns found in healthy control users. A mechanism to automatically estimate a mobility index based on the similarity of the pressure patterns to a stereotyped stride is also used. Both data gathered from stroke survivors and healthy controls are used to evaluate the proposed mechanisms. The output of trained algorithms is applied to the PSMrS system to provide feedback on gait quality enabling stroke survivors to self-manage their rehabilitation.

Real-Time Fall Risk Assessment Using Functional Reach Test.

PubMed

Williams, Brian; Allen, Brandon; Hu, Zhen; True, Hanna; Cho, Jin; Harris, Austin; Fell, Nancy; Sartipi, Mina

2017-01-01

Falls are common and dangerous for survivors of stroke at all stages of recovery. The widespread need to assess fall risk in real time for individuals after stroke has generated emerging requests for a reliable, inexpensive, quantifiable, and remote clinical measure/tool. In order to meet these requests, we explore the Functional Reach Test (FRT) for real-time fall risk assessment and implement the FRT function in mStroke , a real-time and automatic mobile health system for poststroke recovery and rehabilitation. mStroke is designed, developed, and delivered as an Application (App) running on a hardware platform consisting of an iPad and one or two wireless body motion sensors based on different mobile health functions. The FRT function in mStroke is extensively tested on healthy human subjects to verify its concept and feasibility. Preliminary performance will be presented to justify the further exploration of the FRT function in mStroke through clinical trials on individuals after stroke, which may guide its ubiquitous exploitation in the near future.

Hybrid position and orientation tracking for a passive rehabilitation table-top robot.

PubMed

Wojewoda, K K; Culmer, P R; Gallagher, J F; Jackson, A E; Levesley, M C

2017-07-01

This paper presents a real time hybrid 2D position and orientation tracking system developed for an upper limb rehabilitation robot. Designed to work on a table-top, the robot is to enable home-based upper-limb rehabilitative exercise for stroke patients. Estimates of the robot's position are computed by fusing data from two tracking systems, each utilizing a different sensor type: laser optical sensors and a webcam. Two laser optical sensors are mounted on the underside of the robot and track the relative motion of the robot with respect to the surface on which it is placed. The webcam is positioned directly above the workspace, mounted on a fixed stand, and tracks the robot's position with respect to a fixed coordinate system. The optical sensors sample the position data at a higher frequency than the webcam, and a position and orientation fusion scheme is proposed to fuse the data from the two tracking systems. The proposed fusion scheme is validated through an experimental set-up whereby the rehabilitation robot is moved by a humanoid robotic arm replicating previously recorded movements of a stroke patient. The results prove that the presented hybrid position tracking system can track the position and orientation with greater accuracy than the webcam or optical sensors alone. The results also confirm that the developed system is capable of tracking recovery trends during rehabilitation therapy.

Mobile Functional Reach Test in People Who Suffer Stroke: A Pilot Study.

PubMed

Merchán-Baeza, Jose Antonio; González-Sánchez, Manuel; Cuesta-Vargas, Antonio

2015-06-11

Postural instability is one of the major complications found in people who survive a stroke. Parameterizing the Functional Reach Test (FRT) could be useful in clinical practice and basic research, as this test is a clinically accepted tool (for its simplicity, reliability, economy, and portability) to measure the semistatic balance of a subject. The aim of this study is to analyze the reliability in the FRT parameterization using inertial sensor within mobile phones (mobile sensors) for recording kinematic variables in patients who have suffered a stroke. Our hypothesis is that the sensors in mobile phones will be reliable instruments for kinematic study of the FRT. This is a cross-sectional study of 7 subjects over 65 years of age who suffered a stroke. During the execution of FRT, the subjects carried two mobile phones: one placed in the lumbar region and the other one on the trunk. After analyzing the data obtained in the kinematic registration by the mobile sensors, a number of direct and indirect variables were obtained. The variables extracted directly from FRT through the mobile sensors were distance, maximum angular lumbosacral/thoracic displacement, time for maximum angular lumbosacral/thoracic displacement, time of return to the initial position, and total time. Using these data, we calculated speed and acceleration of each. A descriptive analysis of all kinematic outcomes recorded by the two mobile sensors (trunk and lumbar) was developed and the average range achieved in the FRT. Reliability measures were calculated by analyzing the internal consistency of the measures with 95% confidence interval of each outcome variable. We calculated the reliability of mobile sensors in the measurement of the kinematic variables during the execution of the FRT. The values in the FRT obtained in this study (2.49 cm, SD 13.15) are similar to those found in other studies with this population and with the same age range. Intrasubject reliability values observed in the use of mobile phones are all located above 0.831, ranging from 0.831 (time B_C trunk area) and 0.894 (displacement A_B trunk area). Likewise, the observed intersubject values range from 0.835 (time B_C trunk area) and 0.882 (displacement A_C trunk area). On the other hand, the reliability of the FRT was 0.989 (0.981-0.996) and 0.978 (0.970-0.985), intrasubject and intersubject respectively. We found that mobile sensors in mobile phones could be reliable tools in the parameterization of the Functional Reach Test in people who have had a stroke. ©Jose Antonio Merchán-Baeza, Manuel González-Sánchez, Antonio Cuesta-Vargas. Originally published in JMIR Rehabilitation and Assistive Technology (http://rehab.jmir.org), 11.06.2015.

Telehealth, Wearable Sensors, and the Internet: Will They Improve Stroke Outcomes Through Increased Intensity of Therapy, Motivation, and Adherence to Rehabilitation Programs?

PubMed

Burridge, Jane H; Lee, Alan Chong W; Turk, Ruth; Stokes, Maria; Whitall, Jill; Vaidyanathan, Ravi; Clatworthy, Phil; Hughes, Ann-Marie; Meagher, Claire; Franco, Enrico; Yardley, Lucy

2017-07-01

Stroke, predominantly a condition of older age, is a major cause of acquired disability in the global population and puts an increasing burden on health care resources. Clear evidence for the importance of intensity of therapy in optimizing functional outcomes is found in animal models, supported by neuroimaging and behavioral research, and strengthened by recent meta-analyses from multiple clinical trials. However, providing intensive therapy using conventional treatment paradigms is expensive and sometimes not feasible because of social and environmental factors. This article addresses the need for cost-effective increased intensity of practice and suggests potential benefits of telehealth (TH) as an innovative model of care in physical therapy. We provide an overview of TH and present evidence that a web-supported program, used in conjunction with constraint-induced therapy (CIT), can increase intensity and adherence to a rehabilitation regimen. The design and feasibility testing of this web-based program, "LifeCIT," is presented. We describe how wearable sensors can monitor activity and provide feedback to patients and therapists. The methodology for the development of a wearable device with embedded inertial and mechanomyographic sensors, algorithms to classify functional movement, and a graphical user interface to present meaningful data to patients to support a home exercise program is explained. We propose that wearable sensor technologies and TH programs have the potential to provide most-effective, intensive, home-based stroke rehabilitation.

An Energy Saving System for a Beam Pumping Unit

PubMed Central

Lv, Hongqiang; Liu, Jun; Han, Jiuqiang; Jiang, An

2016-01-01

Beam pumping units are widely used in the oil production industry, but the energy efficiency of this artificial lift machinery is generally low, especially for the low-production well and high-production well in the later stage. There are a number of ways for energy savings in pumping units, with the periodic adjustment of stroke speed and rectification of balance deviation being two important methods. In the paper, an energy saving system for a beam pumping unit (ESS-BPU) based on the Internet of Things (IoT) was proposed. A total of four types of sensors, including load sensor, angle sensor, voltage sensor, and current sensor, were used to detect the operating conditions of the pumping unit. Data from these sensors was fed into a controller installed in an oilfield to adjust the stroke speed automatically and estimate the degree of balance in real-time. Additionally, remote supervision could be fulfilled using a browser on a computer or smartphone. Furthermore, the data from a practical application was recorded and analyzed, and it can be seen that ESS-BPU is helpful in reducing energy loss caused by unnecessarily high stroke speed and a poor degree of balance. PMID:27187402

Automating arm movement training following severe stroke: functional exercises with quantitative feedback in a gravity-reduced environment.

PubMed

Sanchez, Robert J; Liu, Jiayin; Rao, Sandhya; Shah, Punit; Smith, Robert; Rahman, Tariq; Cramer, Steven C; Bobrow, James E; Reinkensmeyer, David J

2006-09-01

An important goal in rehabilitation engineering is to develop technology that allows individuals with severe motor impairment to practice arm movement without continuous supervision from a rehabilitation therapist. This paper describes the development of such a system, called Therapy WREX or ("T-WREX"). The system consists of an orthosis that assists in arm movement across a large workspace, a grip sensor that detects hand grip pressure, and software that simulates functional activities. The arm orthosis is an instrumented, adult-sized version of the Wilmington Robotic Exoskeleton (WREX), which is a five degrees-of-freedom mechanism that passively counterbalances the weight of the arm using elastic bands. After providing a detailed design description of T-WREX, this paper describes two pilot studies of the system's capabilities. The first study demonstrated that individuals with chronic stroke whose arm function is compromised in a normal gravity environment can perform reaching and drawing movements while using T-WREX. The second study demonstrated that exercising the affected arm of five people with chronic stroke with T-WREX over an eight week period improved unassisted movement ability (mean change in Fugl-Meyer score was 5 points +/- 2 SD; mean change in range of motion of reaching was 10%, p < 0.001). These results demonstrate the feasibility of automating upper-extremity rehabilitation therapy for people with severe stroke using passive gravity assistance, a grip sensor, and simple virtual reality software.

Range estimation techniques in single-station thunderstorm warning sensors based upon gated, wideband, magnetic direction finder technology

NASA Technical Reports Server (NTRS)

Pifer, Alburt E.; Hiscox, William L.; Cummins, Kenneth L.; Neumann, William T.

1991-01-01

Gated, wideband, magnetic direction finders (DFs) were originally designed to measure the bearing of cloud-to-ground lightning relative to the sensor. A recent addition to this device uses proprietary waveform discrimination logic to select return stroke signatures and certain range dependent features in the waveform to provide an estimate of range of flashes within 50 kms. The enhanced ranging techniques are discussed which were designed and developed for use in single station thunderstorm warning sensor. Included are the results of on-going evaluations being conducted under a variety of meteorological and geographic conditions.

Development of a novel haptic glove for improving finger dexterity in poststroke rehabilitation.

PubMed

Lin, Chi-Ying; Tsai, Chia-Min; Shih, Pei-Cheng; Wu, Hsiao-Ching

2015-01-01

Almost all stroke patients experience a certain degree of fine motor impairment, and impeded finger movement may limit activities in daily life. Thus, to improve the quality of life of stroke patients, designing an efficient training device for fine motor rehabilitation is crucial. This study aimed to develop a novel fine motor training glove that integrates a virtual-reality based interactive environment with vibrotactile feedback for more effective post stroke hand rehabilitation. The proposed haptic rehabilitation device is equipped with small DC vibration motors for vibrotactile feedback stimulation and piezoresistive thin-film force sensors for motor function evaluation. Two virtual-reality based games ``gopher hitting'' and ``musical note hitting'' were developed as a haptic interface. According to the designed rehabilitation program, patients intuitively push and practice their fingers to improve the finger isolation function. Preliminary tests were conducted to assess the feasibility of the developed haptic rehabilitation system and to identify design concerns regarding the practical use in future clinical testing.

Brain-machine interfaces in neurorehabilitation of stroke.

PubMed

Soekadar, Surjo R; Birbaumer, Niels; Slutzky, Marc W; Cohen, Leonardo G

2015-11-01

Stroke is among the leading causes of long-term disabilities leaving an increasing number of people with cognitive, affective and motor impairments depending on assistance in their daily life. While function after stroke can significantly improve in the first weeks and months, further recovery is often slow or non-existent in the more severe cases encompassing 30-50% of all stroke victims. The neurobiological mechanisms underlying recovery in those patients are incompletely understood. However, recent studies demonstrated the brain's remarkable capacity for functional and structural plasticity and recovery even in severe chronic stroke. As all established rehabilitation strategies require some remaining motor function, there is currently no standardized and accepted treatment for patients with complete chronic muscle paralysis. The development of brain-machine interfaces (BMIs) that translate brain activity into control signals of computers or external devices provides two new strategies to overcome stroke-related motor paralysis. First, BMIs can establish continuous high-dimensional brain-control of robotic devices or functional electric stimulation (FES) to assist in daily life activities (assistive BMI). Second, BMIs could facilitate neuroplasticity, thus enhancing motor learning and motor recovery (rehabilitative BMI). Advances in sensor technology, development of non-invasive and implantable wireless BMI-systems and their combination with brain stimulation, along with evidence for BMI systems' clinical efficacy suggest that BMI-related strategies will play an increasing role in neurorehabilitation of stroke. Copyright © 2014. Published by Elsevier Inc.

A combined sEMG and accelerometer system for monitoring functional activity in stroke.

PubMed

Roy, Serge H; Cheng, M Samuel; Chang, Shey-Sheen; Moore, John; De Luca, Gianluca; Nawab, S Hamid; De Luca, Carlo J

2009-12-01

Remote monitoring of physical activity using body-worn sensors provides an alternative to assessment of functional independence by subjective, paper-based questionnaires. This study investigated the classification accuracy of a combined surface electromyographic (sEMG) and accelerometer (ACC) sensor system for monitoring activities of daily living in patients with stroke. sEMG and ACC data (eight channels each) were recorded from 10 hemiparetic patients while they carried out a sequence of 11 activities of daily living (identification tasks), and 10 activities used to evaluate misclassification errors (nonidentification tasks). The sEMG and ACC sensor data were analyzed using a multilayered neural network and an adaptive neuro-fuzzy inference system to identify the minimal sensor configuration needed to accurately classify the identification tasks, with a minimal number of misclassifications from the nonidentification tasks. The results demonstrated that the highest sensitivity and specificity for the identification tasks was achieved using a subset of four ACC sensors and adjacent sEMG sensors located on both upper arms, one forearm, and one thigh, respectively. This configuration resulted in a mean sensitivity of 95.0%, and a mean specificity of 99.7% for the identification tasks, and a mean misclassification error of < 10% for the nonidentification tasks. The findings support the feasibility of a hybrid sEMG and ACC wearable sensor system for automatic recognition of motor tasks used to assess functional independence in patients with stroke.

A Combined sEMG and Accelerometer System for Monitoring Functional Activity in Stroke.

PubMed

Roy, S; Cheng, M; Chang, S; Moore, J; De Luca, G; Nawab, S; De Luca, C

2014-04-23

Remote monitoring of physical activity using bodyworn sensors provides an alternative to assessment of functional independence by subjective, paper-based questionnaires. This study investigated the classification accuracy of a combined surface electromyographic (sEMG) and accelerometer (ACC) sensor system for monitoring activities of daily living in patients with stroke. sEMG and ACC data were recorded from 10 hemi paretic patients while they carried out a sequence of 11 activities of daily living (Identification tasks), and 10 activities used to evaluate misclassification errors (non-Identification tasks). The sEMG and ACC sensor data were analyzed using a multilayered neural network and an adaptive neuro-fuzzy inference system to identify the minimal sensor configuration needed to accurately classify the identification tasks, with a minimal number of misclassifications from the non-Identification tasks. The results demonstrated that the highest sensitivity and specificity for the identification tasks was achieved using a subset of 4 ACC sensors and adjacent sEMG sensors located on both upper arms, one forearm, and one thigh, respectively. This configuration resulted in a mean sensitivity of 95.0 %, and a mean specificity of 99.7 % for the identification tasks, and a mean misclassification error of < 10% for the non-Identification tasks. The findings support the feasibility of a hybrid sEMG and ACC wearable sensor system for automatic recognition of motor tasks used to assess functional independence in patients with stroke.

Implantable radio frequency identification sensors: wireless power and communication.

PubMed

Hutchens, Chriswell; Rennaker, Robert L; Venkataraman, Srinivasan; Ahmed, Rehan; Liao, Ran; Ibrahim, Tamer

2011-01-01

There are significant technical challenges in the development of a fully implantable wirelessly powered neural interface. Challenges include wireless transmission of sufficient power to the implanted device to ensure reliable operation for decades without replacement, minimizing tissue heating, and adequate reliable communications bandwidth. Overcoming these challenges is essential for the development of implantable closed loop system for the treatment of disorders ranging from epilepsy, incontinence, stroke and spinal cord injury. We discuss the development of the wireless power, communication and control for a Radio-Frequency Identification Sensor (RFIDS) system with targeted power range for a 700 mV, 30 to 40 uA load attained at -2 dBm.

Correlations between Angular Velocities in Selected Joints and Velocity of Table Tennis Racket during Topspin Forehand and Backhand

PubMed Central

Bańkosz, Ziemowit; Winiarski, Sławomir

2018-01-01

The aim of this study was to determine the correlations between angular velocities in individual joints and racket velocity for different topspin forehand and backhand strokes in table tennis. Ten elite female table tennis players participated, presenting different kinds of topspin forehands and backhands – after a no-spin ball (FH1, BH1), after a backspin ball (FH2, BH2) and “heavy” topspin (FH3, BH3). Range of motion was measured with the BTS Smart-E (BTS Bioengineering, Milan, Italy) motion analysis system with a specially developed marker placement protocol for the upper body parts and an acoustic sensor attached to the racket to identify ball-racket contact. In forehand strokes angular velocities of internal arm rotation and adduction in shoulder joint correlated with racket velocity. Racket velocity was correlated with angular velocities (hip extension on the playing side; hip flexion on the opposite side; ankle flexion) in the case of a topspin forehand performed with maximal force –”heavy” topspin (FH3). In backhand strokes the velocities of arm abduction and shoulder girdle rotation towards the playing side correlated with racket velocity. The angular velocity of internal arm rotation and adduction in shoulder joint may be important components of a coordinated stroke, whilst angular velocity can substantially affect the racket speed when one is changing the type of stroke. Key points The aim of this study was to calculate correlations between racket velocity and the angular velocities of individual joints and for variants of topspin forehand and backhand strokes in table tennis. A novel model was used to estimate range of motion (specially developed placement protocol for upper body markers and identification of a ball-racket contact using an acoustic sensor attached to the racket). In forehand strokes angular velocities of internal arm rotation and adduction in shoulder joint were correlated with racket velocity. Correlations between racket velocity and the angular velocities of playing- and non-playing-side hip extension and ankle flexion were found in topspin forehands. In topspin backhands abduction of the arm had the greatest impact on the racket speed. The results can be used directly to improve training of table tennis techniques, especially topspin strokes. PMID:29769835

Gesture therapy: a vision-based system for upper extremity stroke rehabilitation.

PubMed

Sucar, L; Luis, Roger; Leder, Ron; Hernandez, Jorge; Sanchez, Israel

2010-01-01

Stroke is the main cause of motor and cognitive disabilities requiring therapy in the world. Therefor it is important to develop rehabilitation technology that allows individuals who had suffered a stroke to practice intensive movement training without the expense of an always-present therapist. We have developed a low-cost vision-based system that allows stroke survivors to practice arm movement exercises at home or at the clinic, with periodic interactions with a therapist. The system integrates a virtual environment for facilitating repetitive movement training, with computer vision algorithms that track the hand of a patient, using an inexpensive camera and a personal computer. This system, called Gesture Therapy, includes a gripper with a pressure sensor to include hand and finger rehabilitation; and it tracks the head of the patient to detect and avoid trunk compensation. It has been evaluated in a controlled clinical trial at the National Institute for Neurology and Neurosurgery in Mexico City, comparing it with conventional occupational therapy. In this paper we describe the latest version of the Gesture Therapy System and summarize the results of the clinical trail.

Design and Realization of a Three Degrees of Freedom Displacement Measurement System Composed of Hall Sensors Based on Magnetic Field Fitting by an Elliptic Function

PubMed Central

Zhao, Bo; Wang, Lei; Tan, Jiu-Bin

2015-01-01

This paper presents the design and realization of a three degrees of freedom (DOFs) displacement measurement system composed of Hall sensors, which is built for the XYθz displacement measurement of the short stroke stage of the reticle stage of lithography. The measurement system consists of three pairs of permanent magnets mounted on the same plane on the short stroke stage along the Y, Y, X directions, and three single axis Hall sensors correspondingly mounted on the frame of the reticle stage. The emphasis is placed on the decoupling and magnetic field fitting of the three DOFs measurement system. The model of the measurement system is illustrated, and the XY positions and θZ rotation of the short stroke stage can be obtained by decoupling the sensor outputs. A magnetic field fitting by an elliptic function-based compensation method is proposed. The practical field intensity of a permanent magnet at a certain plane height can be substituted for the output voltage of a Hall sensors, which can be expressed by the elliptic function through experimental data as the crucial issue to calculate the three DOFs displacement. Experimental results of the Hall sensor displacement measurement system are presented to validate the proposed three DOFs measurement system. PMID:26370993

A Novel Real-Time Path Servo Control of a Hardware-in-the-Loop for a Large-Stroke Asymmetric Rod-Less Pneumatic System under Variable Loads.

PubMed

Lin, Hao-Ting

2017-06-04

This project aims to develop a novel large stroke asymmetric pneumatic servo system of a hardware-in-the-loop for path tracking control under variable loads based on the MATLAB Simulink real-time system. High pressure compressed air provided by the air compressor is utilized for the pneumatic proportional servo valve to drive the large stroke asymmetric rod-less pneumatic actuator. Due to the pressure differences between two chambers, the pneumatic actuator will operate. The highly nonlinear mathematical models of the large stroke asymmetric pneumatic system were analyzed and developed. The functional approximation technique based on the sliding mode controller (FASC) is developed as a controller to solve the uncertain time-varying nonlinear system. The MATLAB Simulink real-time system was a main control unit of a hardware-in-the-loop system proposed to establish driver blocks for analog and digital I/O, a linear encoder, a CPU and a large stroke asymmetric pneumatic rod-less system. By the position sensor, the position signals of the cylinder will be measured immediately. The measured signals will be viewed as the feedback signals of the pneumatic servo system for the study of real-time positioning control and path tracking control. Finally, real-time control of a large stroke asymmetric pneumatic servo system with measuring system, a large stroke asymmetric pneumatic servo system, data acquisition system and the control strategy software will be implemented. Thus, upgrading the high position precision and the trajectory tracking performance of the large stroke asymmetric pneumatic servo system will be realized to promote the high position precision and path tracking capability. Experimental results show that fifth order paths in various strokes and the sine wave path are successfully implemented in the test rig. Also, results of variable loads under the different angle were implemented experimentally.

A Novel Real-Time Path Servo Control of a Hardware-in-the-Loop for a Large-Stroke Asymmetric Rod-Less Pneumatic System under Variable Loads

PubMed Central

Lin, Hao-Ting

2017-01-01

This project aims to develop a novel large stroke asymmetric pneumatic servo system of a hardware-in-the-loop for path tracking control under variable loads based on the MATLAB Simulink real-time system. High pressure compressed air provided by the air compressor is utilized for the pneumatic proportional servo valve to drive the large stroke asymmetric rod-less pneumatic actuator. Due to the pressure differences between two chambers, the pneumatic actuator will operate. The highly nonlinear mathematical models of the large stroke asymmetric pneumatic system were analyzed and developed. The functional approximation technique based on the sliding mode controller (FASC) is developed as a controller to solve the uncertain time-varying nonlinear system. The MATLAB Simulink real-time system was a main control unit of a hardware-in-the-loop system proposed to establish driver blocks for analog and digital I/O, a linear encoder, a CPU and a large stroke asymmetric pneumatic rod-less system. By the position sensor, the position signals of the cylinder will be measured immediately. The measured signals will be viewed as the feedback signals of the pneumatic servo system for the study of real-time positioning control and path tracking control. Finally, real-time control of a large stroke asymmetric pneumatic servo system with measuring system, a large stroke asymmetric pneumatic servo system, data acquisition system and the control strategy software will be implemented. Thus, upgrading the high position precision and the trajectory tracking performance of the large stroke asymmetric pneumatic servo system will be realized to promote the high position precision and path tracking capability. Experimental results show that fifth order paths in various strokes and the sine wave path are successfully implemented in the test rig. Also, results of variable loads under the different angle were implemented experimentally. PMID:28587220

A rehabilitation device to improve the hand grasp function of stroke patients using a patient-driven approach.

PubMed

Park, Wanjoo; Jeong, Wookjin; Kwon, Gyu-Hyun; Kim, Yun-Hee; Kim, Laehyun

2013-06-01

This paper proposes a robotic hand rehabilitation device for grasp training. The device is designed for stroke patients to train and recover their hand grasp function in order to undertake activities of daily living (ADL). The device consists of a control unit, two small actuators, an infrared (IR) sensor, and pressure sensors in the grasp handle. The advantages of this device are that it is small in size, inexpensive, and available for use at home without specialist's supervision. In addition, a novel patient-driven strategy based on the patient's movement intention detected by the pressure sensors without bio-signals is introduced. Once the system detects a patient's movement intention, it triggers the robotic device to move the patient's hand to form the normal grasping behavior. This strategy may encourage stroke patients to participate in rehabilitation training to recover their hand grasp function and it may also enhance neural plasticity. A user study was conducted in order to investigate the usability, acceptability, satisfaction, and suggestions for improvement of the proposed device. The results of this survey included positive reviews from therapists and a stroke patient. In particular, therapists expected that the proposed patient-driven mode can motivate patients for their rehabilitation training and it can be effective to prevent a compensational strategy in active movements. It is expected that the proposed device will assist stroke patients in restoring their grasp function efficiently.

An EMG-Controlled Robotic Hand Exoskeleton for Bilateral Rehabilitation.

PubMed

Leonardis, Daniele; Barsotti, Michele; Loconsole, Claudio; Solazzi, Massimiliano; Troncossi, Marco; Mazzotti, Claudio; Castelli, Vincenzo Parenti; Procopio, Caterina; Lamola, Giuseppe; Chisari, Carmelo; Bergamasco, Massimo; Frisoli, Antonio

2015-01-01

This paper presents a novel electromyography (EMG)-driven hand exoskeleton for bilateral rehabilitation of grasping in stroke. The developed hand exoskeleton was designed with two distinctive features: (a) kinematics with intrinsic adaptability to patient's hand size, and (b) free-palm and free-fingertip design, preserving the residual sensory perceptual capability of touch during assistance in grasping of real objects. In the envisaged bilateral training strategy, the patient's non paretic hand acted as guidance for the paretic hand in grasping tasks. Grasping force exerted by the non paretic hand was estimated in real-time from EMG signals, and then replicated as robotic assistance for the paretic hand by means of the hand-exoskeleton. Estimation of the grasping force through EMG allowed to perform rehabilitation exercises with any, non sensorized, graspable objects. This paper presents the system design, development, and experimental evaluation. Experiments were performed within a group of six healthy subjects and two chronic stroke patients, executing robotic-assisted grasping tasks. Results related to performance in estimation and modulation of the robotic assistance, and to the outcomes of the pilot rehabilitation sessions with stroke patients, positively support validity of the proposed approach for application in stroke rehabilitation.

Design of a nanoscale time-of-flight sensor and an integrated multiscale module for the point-of-care diagnosis of stroke

NASA Astrophysics Data System (ADS)

Andrus, Matthew

Stroke is a leading cause of death and disability in the United States, however, there remains no rapid diagnostic test for differentiating between ischemic and hemorrhagic stroke within the three-hour treatment window. Here we describe the design of a multiscale microfluidic module with an embedded time-of-flight nanosensor for the clinical diagnosis of stroke. The nanosensor described utilizes two synthetic pores in series, relying on resistive pulse sensing (RPS) to measure the passage of molecules through the time-of-flight tube. Once the nanosensor design was completed, a multiscale module to process patient samples and house the sensors was designed in a similar iterative process. This design utilized pillar arrays, called "pixels" to immobilize oligonucleotides from patient samples for ligase detection reactions (LDR) to be carried out. COMSOL simulations were performed to understand the operation and behavior of both the nanosensor and the modular chip once the designs were completed.

Electrification in winter storms and the analysis of thunderstorm overflight

NASA Technical Reports Server (NTRS)

Brook, Marx

1991-01-01

The emergence of 24 hr operational lightning detection networks has led to the finding that positive lightning strokes, although still much fewer in number than the normal negative strokes, are present in summer and winter storms. Recent papers address the importance of understanding the meteorological conditions which lead to a dominance of one polarity of stroke over another; the appearance of positive strokes at the end of a storm appeared to presage the end-of-storm downdraft and subsidence leading to downburst activity. It is beginning to appear that positive strokes may be important meteorological indicators. Significant research accomplishments on the following topics are addressed: (1) a study to verify that the black boxes used in the lightning networks to detect both negative and positive strokes to ground were accurate; (2) the use of slow tails to determine the polarity of distant lightning; (3) lightning initiation in winter vs. summer storms; (4) the upgrade of sensors for the measurement of electric field signals associated with lightning; (5) the analysis of lightning flash records from storms between 40 and 125 km from the sensor; and (6) an interesting aspect of the initiation process which involves the physical processes driving the stepped leader. The focus of current research and future research plans are presented.

Wavelet PCA for automatic identification of walking with and without an exoskeleton on a treadmill using pressure and accelerometer sensors.

PubMed

Naik, Ganesh R; Pendharkar, Gita; Nguyen, Hung T

2016-08-01

Nowadays portable devices with more number of sensors are used for gait assessment and monitoring for elderly and disabled. However, the problem with using multiple sensors is that if they are placed on the same platform or base, there could be cross talk between them, which could change the signal amplitude or add noise to the signal. Hence, this study uses wavelet PCA as a signal processing technique to separate the original sensor signal from the signal obtained from the sensors through the integrated unit to compare the two types of walking (with and without an exoskeleton). This comparison using wavelet PCA will enable the researchers to obtain accurate sensor data and compare and analyze the data in order to further improve the design of compact portable devices used to monitor and assess the gait in stroke or paralyzed subjects. The advantage of designing such systems is that they can also be used to assess and monitor the gait of the stroke subjects at home, which will save them time and efforts to visit the laboratory or clinic.

Design and characterization of a wearable macrobending fiber optic sensor for human joint angle determination

NASA Astrophysics Data System (ADS)

Silva, Ana S.; Catarino, André; Correia, Miguel V.; Frazão, Orlando

2013-12-01

The work presented here describes the development and characterization of intensity fiber optic sensor integrated in a specifically designed piece of garment to measure elbow flexion. The sensing head is based on macrobending incorporated in the garment, and the increase of curvature number was studied in order to investigate which scheme provided a good result in terms of sensitivity and repeatability. Results showed the configuration that assured a higher sensitivity (0.644 dBm/deg) and better repeatability was the one with four loops. Ultimately, this sensor can be used for rehabilitation purposes to monitor human joint angles, namely, elbow flexion on stroke survivors while performing the reach functional task, which is the most common upper-limb human gesture.

Mathematical Formulation of the Remote Electric and Magnetic Emissions of the Lightning Dart Leader and Return Stroke

NASA Astrophysics Data System (ADS)

Thiemann, Edward M. B.

Lightning detection and geolocation networks have found widespread use by the utility, air traffic control and forestry industries as a means of locating strikes and predicting imminent recurrence. Accurate lightning geolocation requires detecting VLF radio emissions at multiple sites using a distributed sensor network with typical baselines exceeding 150 km, along with precision time of arrival estimation to triangulate the origin of a strike. The trend has been towards increasing network accuracy without increasing sensor density by incorporating precision GPS synchronized clocks and faster front-end signal processing. Because lightning radio waveforms evolve as they propagate over a finitely conducting earth, and that measurements for a given strike may have disparate propagation path lengths, accurate models are required to determine waveform fiducials for precise strike location. The transition between the leader phase and return stroke phase may offer such a fiducial and warrants quantitative modeling to improve strike location accuracy. The VLF spectrum of the ubiquitous downward negative lightning strike is able to be modeled by the transfer of several Coulombs of negative charge from cloud to ground in a two-step process. The lightning stepped leader ionizes a plasma channel downward from the cloud at a velocity of approximately 0.05c, leaving a column of charge in its path. Upon connection with a streamer, the subsequent return stroke initiates at or near ground level and travels upward at an average but variable velocity of 0.3c. The return stroke neutralizes any negative charge along its path. Subsequent dart leader and return strokes often travel smoothly down the heated channel left by a preceding stroke, lacking the halting motion of the preceding initial stepped leader and initial return stroke. Existing lightning models often neglect the leader current and rely on approximations when solving for the return stroke. In this thesis, I present an analytic solution to Maxwell's Equations for the lightning leader followed by a novel return stroke model. I model the leader as a downward propagating boxcar function of uniform charge density and constant velocity, and the subsequent return stroke is modeled as an upward propagating boxcar with a time dependent velocity. Charge conservation is applied to ensure self-consistency of the driving current and charge sources, and physical observations are used to support model development. The resulting transient electric and magnetic fields are presented at various distances and delay times and compared with measured waveforms and previously published models.

Geometrical Effects on the Electromagnetic Radiation from Lightning Return Strokes

NASA Technical Reports Server (NTRS)

Willett, J. C.; Smith, D. A.; LeVine, D. M.; Zukor, Dorothy J. (Technical Monitor)

2001-01-01

The morphological difference between the electromagnetic radiation-field waveforms of "first" and "subsequent" return strokes in cloud-to-ground lightning flashes is well known and can be used to identify the formation of new channels to ground. This difference is generally believed due to the existence of branches on first-stroke channels, whereas subsequent strokes re-illuminate only the main channel of a previous stroke; but experimental evidence for this hypothesis is relatively weak. It has been argued for the influence of channel geometry on the fine structure of radiation from subsequent return strokes by comparing the field-change waveforms recorded at the same station from strokes within the same flash and between different flashes of both natural and triggered lightning. The present paper introduces new evidence for both of these hypotheses from a comparison of waveforms between sensors in different directions from the same stroke.

Feature selection for wearable smartphone-based human activity recognition with able bodied, elderly, and stroke patients.

PubMed

Capela, Nicole A; Lemaire, Edward D; Baddour, Natalie

2015-01-01

Human activity recognition (HAR), using wearable sensors, is a growing area with the potential to provide valuable information on patient mobility to rehabilitation specialists. Smartphones with accelerometer and gyroscope sensors are a convenient, minimally invasive, and low cost approach for mobility monitoring. HAR systems typically pre-process raw signals, segment the signals, and then extract features to be used in a classifier. Feature selection is a crucial step in the process to reduce potentially large data dimensionality and provide viable parameters to enable activity classification. Most HAR systems are customized to an individual research group, including a unique data set, classes, algorithms, and signal features. These data sets are obtained predominantly from able-bodied participants. In this paper, smartphone accelerometer and gyroscope sensor data were collected from populations that can benefit from human activity recognition: able-bodied, elderly, and stroke patients. Data from a consecutive sequence of 41 mobility tasks (18 different tasks) were collected for a total of 44 participants. Seventy-six signal features were calculated and subsets of these features were selected using three filter-based, classifier-independent, feature selection methods (Relief-F, Correlation-based Feature Selection, Fast Correlation Based Filter). The feature subsets were then evaluated using three generic classifiers (Naïve Bayes, Support Vector Machine, j48 Decision Tree). Common features were identified for all three populations, although the stroke population subset had some differences from both able-bodied and elderly sets. Evaluation with the three classifiers showed that the feature subsets produced similar or better accuracies than classification with the entire feature set. Therefore, since these feature subsets are classifier-independent, they should be useful for developing and improving HAR systems across and within populations.

Feature Selection for Wearable Smartphone-Based Human Activity Recognition with Able bodied, Elderly, and Stroke Patients

PubMed Central

2015-01-01

Human activity recognition (HAR), using wearable sensors, is a growing area with the potential to provide valuable information on patient mobility to rehabilitation specialists. Smartphones with accelerometer and gyroscope sensors are a convenient, minimally invasive, and low cost approach for mobility monitoring. HAR systems typically pre-process raw signals, segment the signals, and then extract features to be used in a classifier. Feature selection is a crucial step in the process to reduce potentially large data dimensionality and provide viable parameters to enable activity classification. Most HAR systems are customized to an individual research group, including a unique data set, classes, algorithms, and signal features. These data sets are obtained predominantly from able-bodied participants. In this paper, smartphone accelerometer and gyroscope sensor data were collected from populations that can benefit from human activity recognition: able-bodied, elderly, and stroke patients. Data from a consecutive sequence of 41 mobility tasks (18 different tasks) were collected for a total of 44 participants. Seventy-six signal features were calculated and subsets of these features were selected using three filter-based, classifier-independent, feature selection methods (Relief-F, Correlation-based Feature Selection, Fast Correlation Based Filter). The feature subsets were then evaluated using three generic classifiers (Naïve Bayes, Support Vector Machine, j48 Decision Tree). Common features were identified for all three populations, although the stroke population subset had some differences from both able-bodied and elderly sets. Evaluation with the three classifiers showed that the feature subsets produced similar or better accuracies than classification with the entire feature set. Therefore, since these feature subsets are classifier-independent, they should be useful for developing and improving HAR systems across and within populations. PMID:25885272

Artificial Roughness Encoding with a Bio-inspired MEMS- based Tactile Sensor Array

PubMed Central

Oddo, Calogero Maria; Beccai, Lucia; Felder, Martin; Giovacchini, Francesco; Carrozza, Maria Chiara

2009-01-01

A compliant 2×2 tactile sensor array was developed and investigated for roughness encoding. State of the art cross shape 3D MEMS sensors were integrated with polymeric packaging providing in total 16 sensitive elements to external mechanical stimuli in an area of about 20 mm2, similarly to the SA1 innervation density in humans. Experimental analysis of the bio-inspired tactile sensor array was performed by using ridged surfaces, with spatial periods from 2.6 mm to 4.1 mm, which were indented with regulated 1N normal force and stroked at constant sliding velocity from 15 mm/s to 48 mm/s. A repeatable and expected frequency shift of the sensor outputs depending on the applied stimulus and on its scanning velocity was observed between 3.66 Hz and 18.46 Hz with an overall maximum error of 1.7%. The tactile sensor could also perform contact imaging during static stimulus indentation. The experiments demonstrated the suitability of this approach for the design of a roughness encoding tactile sensor for an artificial fingerpad. PMID:22412304

Breakup and then makeup: a predictive model of how cilia self-regulate hardness for posture control.

PubMed

Bandyopadhyay, Promode R; Hansen, Joshua C

2013-01-01

Functioning as sensors and propulsors, cilia are evolutionarily conserved organelles having a highly organized internal structure. How a paramecium's cilium produces off-propulsion-plane curvature during its return stroke for symmetry breaking and drag reduction is not known. We explain these cilium deformations by developing a torsional pendulum model of beat frequency dependence on viscosity and an olivo-cerebellar model of self-regulation of posture control. The phase dependence of cilia torsion is determined, and a bio-physical model of hardness control with predictive features is offered. Crossbridge links between the central microtubule pair harden the cilium during the power stroke; this stroke's end is a critical phase during which ATP molecules soften the crossbridge-microtubule attachment at the cilium inflection point where torsion is at its maximum. A precipitous reduction in hardness ensues, signaling the start of ATP hydrolysis that re-hardens the cilium. The cilium attractor basin could be used as reference for perturbation sensing.

Breakup and then makeup: a predictive model of how cilia self-regulate hardness for posture control

NASA Astrophysics Data System (ADS)

Bandyopadhyay, Promode R.; Hansen, Joshua C.

2013-06-01

Functioning as sensors and propulsors, cilia are evolutionarily conserved organelles having a highly organized internal structure. How a paramecium's cilium produces off-propulsion-plane curvature during its return stroke for symmetry breaking and drag reduction is not known. We explain these cilium deformations by developing a torsional pendulum model of beat frequency dependence on viscosity and an olivo-cerebellar model of self-regulation of posture control. The phase dependence of cilia torsion is determined, and a bio-physical model of hardness control with predictive features is offered. Crossbridge links between the central microtubule pair harden the cilium during the power stroke; this stroke's end is a critical phase during which ATP molecules soften the crossbridge-microtubule attachment at the cilium inflection point where torsion is at its maximum. A precipitous reduction in hardness ensues, signaling the start of ATP hydrolysis that re-hardens the cilium. The cilium attractor basin could be used as reference for perturbation sensing.

Breakup and then makeup: a predictive model of how cilia self-regulate hardness for posture control

PubMed Central

Bandyopadhyay, Promode R.; Hansen, Joshua C.

2013-01-01

Functioning as sensors and propulsors, cilia are evolutionarily conserved organelles having a highly organized internal structure. How a paramecium's cilium produces off-propulsion-plane curvature during its return stroke for symmetry breaking and drag reduction is not known. We explain these cilium deformations by developing a torsional pendulum model of beat frequency dependence on viscosity and an olivo-cerebellar model of self-regulation of posture control. The phase dependence of cilia torsion is determined, and a bio-physical model of hardness control with predictive features is offered. Crossbridge links between the central microtubule pair harden the cilium during the power stroke; this stroke's end is a critical phase during which ATP molecules soften the crossbridge-microtubule attachment at the cilium inflection point where torsion is at its maximum. A precipitous reduction in hardness ensues, signaling the start of ATP hydrolysis that re-hardens the cilium. The cilium attractor basin could be used as reference for perturbation sensing. PMID:23739771

A comparison of two ground-based lightning detection networks against the satellite-based lightning imaging sensor (LIS)

NASA Astrophysics Data System (ADS)

Thompson, Kelsey B.

We compared lightning stroke data from the ground-based World Wide Lightning Location Network (WWLLN) and lightning stroke data from the ground-based Earth Networks Total Lightning Network (ENTLN) to lightning group data from the satellite-based Lightning Imaging Sensor (LIS) from 1 January 2010 through 30 June 2011. The region of study, about 39°S to 39°N latitude, 164°E to 17°W longitude, chosen to approximate the Geostationary Lightning Mapper (GLM) field of view, was considered in its entirety and then divided into four geographical sub-regions. We found the highest 18-mon WWLLN coincidence percent (CP) value in the Pacific Ocean at 18.9% and the highest 18-mon ENTLN CP value in North America at 63.3%. We found the lowest 18-mon CP value for both WWLLN and ENTLN in South America at 6.2% and 2.2% respectively. Daily CP values and how often large radiance LIS groups had a coincident stroke varied. Coincidences between LIS groups and ENTLN strokes often resulted in more cloud than ground coincidences in North America and more ground than cloud coincidences in the other three sub-regions.

A multi-channel biomimetic neuroprosthesis to support treadmill gait training in stroke patients.

PubMed

Chia, Noelia; Ambrosini, Emilia; Baccinelli, Walter; Nardone, Antonio; Monticone, Marco; Ferrigno, Giancarlo; Pedrocchi, Alessandra; Ferrante, Simona

2015-01-01

This study presents an innovative multi-channel neuroprosthesis that induces a biomimetic activation of the main lower-limb muscles during treadmill gait training to be used in the rehabilitation of stroke patients. The electrostimulation strategy replicates the physiological muscle synergies used by healthy subjects to walk on a treadmill at their self-selected speed. This strategy is mapped to the current gait sub-phases, which are identified in real time by a custom algorithm. This algorithm divides the gait cycle into six sub-phases, based on two inertial sensors placed laterally on the shanks. Therefore, the pre-defined stimulation profiles are expanded or stretched based on the actual gait pattern of each single subject. A preliminary experimental protocol, involving 10 healthy volunteers, was carried out to extract the muscle synergies and validate the gait-detection algorithm, which were afterwards used in the development of the neuroprosthesis. The feasibility of the neuroprosthesis was tested on one healthy subject who simulated different gait patterns, and a chronic stroke patient. The results showed the correct functioning of the system. A pilot study of the neurorehabilitation treatment for stroke patients is currently being carried out.

Oxide nanomembrane hybrids with enhanced mechano- and thermo-sensitivity for semitransparent epidermal electronics.

PubMed

Park, Minjoon; Do, Kyungsik; Kim, Jaemin; Son, Donghee; Koo, Ja Hoon; Park, Jinkyung; Song, Jun-Kyul; Kim, Ji Hoon; Lee, Minbaek; Hyeon, Taeghwan; Kim, Dae-Hyeong

2015-05-01

Oxide nanomembrane hybrids with enhanced mechano- and thermo-sensitivity for semitransparent epidermal electronics are developed. The use of nanomaterials (single wall nanotubes and silver nanoparticles) embedded in the oxide nanomembranes significantly enhances mechanical and thermal sensitivities. These mechanical and thermal sensors are utilized in wheelchair control and hypothermia detection, which are useful for patients with strokes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Design and testing of a novel multi-stroke micropositioning system with variable resolutions.

PubMed

Xu, Qingsong

2014-02-01

Multi-stroke stages are demanded in micro-/nanopositioning applications which require smaller and larger motion strokes with fine and coarse resolutions, respectively. This paper presents the conceptual design of a novel multi-stroke, multi-resolution micropositioning stage driven by a single actuator for each working axis. It eliminates the issue of the interference among different drives, which resides in conventional multi-actuation stages. The stage is devised based on a fully compliant variable stiffness mechanism, which exhibits unequal stiffnesses in different strokes. Resistive strain sensors are employed to offer variable position resolutions in the different strokes. To quantify the design of the motion strokes and coarse/fine resolution ratio, analytical models are established. These models are verified through finite-element analysis simulations. A proof-of-concept prototype XY stage is designed, fabricated, and tested to demonstrate the feasibility of the presented ideas. Experimental results of static and dynamic testing validate the effectiveness of the proposed design.

Pulse oximeter plethysmographic waveform changes in awake, spontaneously breathing, hypovolemic volunteers.

PubMed

McGrath, Susan P; Ryan, Kathy L; Wendelken, Suzanne M; Rickards, Caroline A; Convertino, Victor A

2011-02-01

The primary objective of this study was to determine whether alterations in the pulse oximeter waveform characteristics would track progressive reductions in central blood volume. We also assessed whether changes in the pulse oximeter waveform provide an indication of blood loss in the hemorrhaging patient before changes in standard vital signs. Pulse oximeter data from finger, forehead, and ear pulse oximeter sensors were collected from 18 healthy subjects undergoing progressive reduction in central blood volume induced by lower body negative pressure (LBNP). Stroke volume measurements were simultaneously recorded using impedance cardiography. The study was conducted in a research laboratory setting where no interventions were performed. Pulse amplitude, width, and area under the curve (AUC) features were calculated from each pulse wave recording. Amalgamated correlation coefficients were calculated to determine the relationship between the changes in pulse oximeter waveform features and changes in stroke volume with LBNP. For pulse oximeter sensors on the ear and forehead, reductions in pulse amplitude, width, and area were strongly correlated with progressive reductions in stroke volume during LBNP (R(2) ≥ 0.59 for all features). Changes in pulse oximeter waveform features were observed before profound decreases in arterial blood pressure. The best correlations between pulse features and stroke volume were obtained from the forehead sensor area (R(2) = 0.97). Pulse oximeter waveform features returned to baseline levels when central blood volume was restored. These results support the use of pulse oximeter waveform analysis as a potential diagnostic tool to detect clinically significant hypovolemia before the onset of cardiovascular decompensation in spontaneously breathing patients.

Design of a Minimum Surface-Effect Tendon-Based Microactuator for Micromanipulation

NASA Technical Reports Server (NTRS)

Goldfarb, Michael; Lipsey, James H.

1997-01-01

A piezoelectric (PZT) stack-based actuator was developed to provide a means of actuation with dynamic characteristics appropriate for small-scale manipulation. In particular, the design incorporates a highly nonlinear, large-ratio transmission that provides approximately two orders of magnitude motion amplification from the PZT stack. In addition to motion amplification, the nonlinear transmission was designed via optimization methods to distort the highly non-uniform properties of a piezoelectric actuator so that the achievable actuation force is nearly constant throughout the actuator workspace. The package also includes sensors that independently measure actuator output force and displacement, so that a manipulator structure need not incorporate sensors nor the associated wires. Specifically, the actuator was designed to output a maximum force of at least one Newton through a stroke of at least one millimeter. For purposes of small-scale precision position and/or force control, the actuator/sensor package was designed to eliminate stick-slip friction and backlash. The overall dimensions of the actuator/sensor package are approximately 40 x 65 x 25 mm.

[Remote intelligent Brunnstrom assessment system for upper limb rehabilitation for post-stroke based on extreme learning machine].

PubMed

Wang, Yue; Yu, Lei; Fu, Jianming; Fang, Qiang

2014-04-01

In order to realize an individualized and specialized rehabilitation assessment of remoteness and intelligence, we set up a remote intelligent assessment system of upper limb movement function of post-stroke patients during rehabilitation. By using the remote rehabilitation training sensors and client data sampling software, we collected and uploaded the gesture data from a patient's forearm and upper arm during rehabilitation training to database of the server. Then a remote intelligent assessment system, which had been developed based on the extreme learning machine (ELM) algorithm and Brunnstrom stage assessment standard, was used to evaluate the gesture data. To evaluate the reliability of the proposed method, a group of 23 stroke patients, whose upper limb movement functions were in different recovery stages, and 4 healthy people, whose upper limb movement functions were normal, were recruited to finish the same training task. The results showed that, compared to that of the experienced rehabilitation expert who used the Brunnstrom stage standard table, the accuracy of the proposed remote Brunnstrom intelligent assessment system can reach a higher level, as 92.1%. The practical effects of surgery have proved that the proposed system could realize the intelligent assessment of upper limb movement function of post-stroke patients remotely, and it could also make the rehabilitation of the post-stroke patients at home or in a community care center possible.

Correlations between Angular Velocities in Selected Joints and Velocity of Table Tennis Racket during Topspin Forehand and Backhand.

PubMed

Bańkosz, Ziemowit; Winiarski, Sławomir

2018-06-01

The aim of this study was to determine the correlations between angular velocities in individual joints and racket velocity for different topspin forehand and backhand strokes in table tennis. Ten elite female table tennis players participated, presenting different kinds of topspin forehands and backhands - after a no-spin ball (FH1, BH1), after a backspin ball (FH2, BH2) and "heavy" topspin (FH3, BH3). Range of motion was measured with the BTS Smart-E (BTS Bioengineering, Milan, Italy) motion analysis system with a specially developed marker placement protocol for the upper body parts and an acoustic sensor attached to the racket to identify ball-racket contact. In forehand strokes angular velocities of internal arm rotation and adduction in shoulder joint correlated with racket velocity. Racket velocity was correlated with angular velocities (hip extension on the playing side; hip flexion on the opposite side; ankle flexion) in the case of a topspin forehand performed with maximal force -"heavy" topspin (FH3). In backhand strokes the velocities of arm abduction and shoulder girdle rotation towards the playing side correlated with racket velocity. The angular velocity of internal arm rotation and adduction in shoulder joint may be important components of a coordinated stroke, whilst angular velocity can substantially affect the racket speed when one is changing the type of stroke.

Activity Recognition for Persons With Stroke Using Mobile Phone Technology: Toward Improved Performance in a Home Setting.

PubMed

O'Brien, Megan K; Shawen, Nicholas; Mummidisetty, Chaithanya K; Kaur, Saninder; Bo, Xiao; Poellabauer, Christian; Kording, Konrad; Jayaraman, Arun

2017-05-25

Smartphones contain sensors that measure movement-related data, making them promising tools for monitoring physical activity after a stroke. Activity recognition (AR) systems are typically trained on movement data from healthy individuals collected in a laboratory setting. However, movement patterns change after a stroke (eg, gait impairment), and activities may be performed differently at home than in a lab. Thus, it is important to validate AR for gait-impaired stroke patients in a home setting for accurate clinical predictions. In this study, we sought to evaluate AR performance in a home setting for individuals who had suffered a stroke, by using different sets of training activities. Specifically, we compared AR performance for persons with stroke while varying the origin of training data, based on either population (healthy persons or persons with stoke) or environment (laboratory or home setting). Thirty individuals with stroke and fifteen healthy subjects performed a series of mobility-related activities, either in a laboratory or at home, while wearing a smartphone. A custom-built app collected signals from the phone's accelerometer, gyroscope, and barometer sensors, and subjects self-labeled the mobility activities. We trained a random forest AR model using either healthy or stroke activity data. Primary measures of AR performance were (1) the mean recall of activities and (2) the misclassification of stationary and ambulatory activities. A classifier trained on stroke activity data performed better than one trained on healthy activity data, improving average recall from 53% to 75%. The healthy-trained classifier performance declined with gait impairment severity, more often misclassifying ambulatory activities as stationary ones. The classifier trained on in-lab activities had a lower average recall for at-home activities (56%) than for in-lab activities collected on a different day (77%). Stroke-based training data is needed for high quality AR among gait-impaired individuals with stroke. Additionally, AR systems for home and community monitoring would likely benefit from including at-home activities in the training data. ©Megan K O'Brien, Nicholas Shawen, Chaithanya K Mummidisetty, Saninder Kaur, Xiao Bo, Christian Poellabauer, Konrad Kording, Arun Jayaraman. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 25.05.2017.

A strategy for computer-assisted mental practice in stroke rehabilitation.

PubMed

Gaggioli, Andrea; Meneghini, Andrea; Morganti, Francesca; Alcaniz, Mariano; Riva, Giuseppe

2006-12-01

To investigate the technical and clinical viability of using computer-facilitated mental practice in the rehabilitation of upper-limb hemiparesis following stroke. A single-case study. Academic-affiliated rehabilitation center. A 46-year-old man with stable motor deficit of the upper right limb following subcortical ischemic stroke. Three computer-enhanced mental practice sessions per week at the rehabilitation center, in addition to usual physical therapy. A custom-made virtual reality system equipped with arm-tracking sensors was used to guide mental practice. The system was designed to superimpose over the (unseen) paretic arm a virtual reconstruction of the movement registered from the nonparetic arm. The laboratory intervention was followed by a 1-month home-rehabilitation program, making use of a portable display device. Pretreatment and posttreatment clinical assessment measures were the upper-extremity scale of the Fugl-Meyer Assessment of Sensorimotor Impairment and the Action Research Arm Test. Performance of the affected arm was evaluated using the healthy arm as the control condition. The patient's paretic limb improved after the first phase of intervention, with modest increases after home rehabilitation, as indicated by functional assessment scores and sensors data. Results suggest that technology-supported mental training is a feasible and potentially effective approach for improving motor skills after stroke.

A Human-machine-interface Integrating Low-cost Sensors with a Neuromuscular Electrical Stimulation System for Post-stroke Balance Rehabilitation.

PubMed

Kumar, Deepesh; Das, Abhijit; Lahiri, Uttama; Dutta, Anirban

2016-04-12

A stroke is caused when an artery carrying blood from heart to an area in the brain bursts or a clot obstructs the blood flow to brain thereby preventing delivery of oxygen and nutrients. About half of the stroke survivors are left with some degree of disability. Innovative methodologies for restorative neurorehabilitation are urgently required to reduce long-term disability. The ability of the nervous system to reorganize its structure, function and connections as a response to intrinsic or extrinsic stimuli is called neuroplasticity. Neuroplasticity is involved in post-stroke functional disturbances, but also in rehabilitation. Beneficial neuroplastic changes may be facilitated with non-invasive electrotherapy, such as neuromuscular electrical stimulation (NMES) and sensory electrical stimulation (SES). NMES involves coordinated electrical stimulation of motor nerves and muscles to activate them with continuous short pulses of electrical current while SES involves stimulation of sensory nerves with electrical current resulting in sensations that vary from barely perceivable to highly unpleasant. Here, active cortical participation in rehabilitation procedures may be facilitated by driving the non-invasive electrotherapy with biosignals (electromyogram (EMG), electroencephalogram (EEG), electrooculogram (EOG)) that represent simultaneous active perception and volitional effort. To achieve this in a resource-poor setting, e.g., in low- and middle-income countries, we present a low-cost human-machine-interface (HMI) by leveraging recent advances in off-the-shelf video game sensor technology. In this paper, we discuss the open-source software interface that integrates low-cost off-the-shelf sensors for visual-auditory biofeedback with non-invasive electrotherapy to assist postural control during balance rehabilitation. We demonstrate the proof-of-concept on healthy volunteers.

A Human-machine-interface Integrating Low-cost Sensors with a Neuromuscular Electrical Stimulation System for Post-stroke Balance Rehabilitation

PubMed Central

Kumar, Deepesh; Das, Abhijit; Lahiri, Uttama; Dutta, Anirban

2016-01-01

A stroke is caused when an artery carrying blood from heart to an area in the brain bursts or a clot obstructs the blood flow to brain thereby preventing delivery of oxygen and nutrients. About half of the stroke survivors are left with some degree of disability. Innovative methodologies for restorative neurorehabilitation are urgently required to reduce long-term disability. The ability of the nervous system to reorganize its structure, function and connections as a response to intrinsic or extrinsic stimuli is called neuroplasticity. Neuroplasticity is involved in post-stroke functional disturbances, but also in rehabilitation. Beneficial neuroplastic changes may be facilitated with non-invasive electrotherapy, such as neuromuscular electrical stimulation (NMES) and sensory electrical stimulation (SES). NMES involves coordinated electrical stimulation of motor nerves and muscles to activate them with continuous short pulses of electrical current while SES involves stimulation of sensory nerves with electrical current resulting in sensations that vary from barely perceivable to highly unpleasant. Here, active cortical participation in rehabilitation procedures may be facilitated by driving the non-invasive electrotherapy with biosignals (electromyogram (EMG), electroencephalogram (EEG), electrooculogram (EOG)) that represent simultaneous active perception and volitional effort. To achieve this in a resource-poor setting, e.g., in low- and middle-income countries, we present a low-cost human-machine-interface (HMI) by leveraging recent advances in off-the-shelf video game sensor technology. In this paper, we discuss the open-source software interface that integrates low-cost off-the-shelf sensors for visual-auditory biofeedback with non-invasive electrotherapy to assist postural control during balance rehabilitation. We demonstrate the proof-of-concept on healthy volunteers. PMID:27166666

Improving activity recognition using a wearable barometric pressure sensor in mobility-impaired stroke patients.

PubMed

Massé, Fabien; Gonzenbach, Roman R; Arami, Arash; Paraschiv-Ionescu, Anisoara; Luft, Andreas R; Aminian, Kamiar

2015-08-25

Stroke survivors often suffer from mobility deficits. Current clinical evaluation methods, including questionnaires and motor function tests, cannot provide an objective measure of the patients' mobility in daily life. Physical activity performance in daily-life can be assessed using unobtrusive monitoring, for example with a single sensor module fixed on the trunk. Existing approaches based on inertial sensors have limited performance, particularly in detecting transitions between different activities and postures, due to the inherent inter-patient variability of kinematic patterns. To overcome these limitations, one possibility is to use additional information from a barometric pressure (BP) sensor. Our study aims at integrating BP and inertial sensor data into an activity classifier in order to improve the activity (sitting, standing, walking, lying) recognition and the corresponding body elevation (during climbing stairs or when taking an elevator). Taking into account the trunk elevation changes during postural transitions (sit-to-stand, stand-to-sit), we devised an event-driven activity classifier based on fuzzy-logic. Data were acquired from 12 stroke patients with impaired mobility, using a trunk-worn inertial and BP sensor. Events, including walking and lying periods and potential postural transitions, were first extracted. These events were then fed into a double-stage hierarchical Fuzzy Inference System (H-FIS). The first stage processed the events to infer activities and the second stage improved activity recognition by applying behavioral constraints. Finally, the body elevation was estimated using a pattern-enhancing algorithm applied on BP. The patients were videotaped for reference. The performance of the algorithm was estimated using the Correct Classification Rate (CCR) and F-score. The BP-based classification approach was benchmarked against a previously-published fuzzy-logic classifier (FIS-IMU) and a conventional epoch-based classifier (EPOCH). The algorithm performance for posture/activity detection, in terms of CCR was 90.4 %, with 3.3 % and 5.6 % improvements against FIS-IMU and EPOCH, respectively. The proposed classifier essentially benefits from a better recognition of standing activity (70.3 % versus 61.5 % [FIS-IMU] and 42.5 % [EPOCH]) with 98.2 % CCR for body elevation estimation. The monitoring and recognition of daily activities in mobility-impaired stoke patients can be significantly improved using a trunk-fixed sensor that integrates BP, inertial sensors, and an event-based activity classifier.

Interactive wearable systems for upper body rehabilitation: a systematic review.

PubMed

Wang, Qi; Markopoulos, Panos; Yu, Bin; Chen, Wei; Timmermans, Annick

2017-03-11

The development of interactive rehabilitation technologies which rely on wearable-sensing for upper body rehabilitation is attracting increasing research interest. This paper reviews related research with the aim: 1) To inventory and classify interactive wearable systems for movement and posture monitoring during upper body rehabilitation, regarding the sensing technology, system measurements and feedback conditions; 2) To gauge the wearability of the wearable systems; 3) To inventory the availability of clinical evidence supporting the effectiveness of related technologies. A systematic literature search was conducted in the following search engines: PubMed, ACM, Scopus and IEEE (January 2010-April 2016). Forty-five papers were included and discussed in a new cuboid taxonomy which consists of 3 dimensions: sensing technology, feedback modalities and system measurements. Wearable sensor systems were developed for persons in: 1) Neuro-rehabilitation: stroke (n = 21), spinal cord injury (n = 1), cerebral palsy (n = 2), Alzheimer (n = 1); 2) Musculoskeletal impairment: ligament rehabilitation (n = 1), arthritis (n = 1), frozen shoulder (n = 1), bones trauma (n = 1); 3) Others: chronic pulmonary obstructive disease (n = 1), chronic pain rehabilitation (n = 1) and other general rehabilitation (n = 14). Accelerometers and inertial measurement units (IMU) are the most frequently used technologies (84% of the papers). They are mostly used in multiple sensor configurations to measure upper limb kinematics and/or trunk posture. Sensors are placed mostly on the trunk, upper arm, the forearm, the wrist, and the finger. Typically sensors are attachable rather than embedded in wearable devices and garments; although studies that embed and integrate sensors are increasing in the last 4 years. 16 studies applied knowledge of result (KR) feedback, 14 studies applied knowledge of performance (KP) feedback and 15 studies applied both in various modalities. 16 studies have conducted their evaluation with patients and reported usability tests, while only three of them conducted clinical trials including one randomized clinical trial. This review has shown that wearable systems are used mostly for the monitoring and provision of feedback on posture and upper extremity movements in stroke rehabilitation. The results indicated that accelerometers and IMUs are the most frequently used sensors, in most cases attached to the body through ad hoc contraptions for the purpose of improving range of motion and movement performance during upper body rehabilitation. Systems featuring sensors embedded in wearable appliances or garments are only beginning to emerge. Similarly, clinical evaluations are scarce and are further needed to provide evidence on effectiveness and pave the path towards implementation in clinical settings.

Passive Wearable Skin Patch Sensor Measures Limb Hemodynamics Based on Electromagnetic Resonance.

PubMed

Cluff, Kim; Becker, Ryan; Jayakumar, Balakumar; Han, Kiyun; Condon, Ernie; Dudley, Kenneth; Szatkowski, George; Pipinos, Iraklis I; Amick, Ryan Z; Patterson, Jeremy

2018-04-01

The objectives of this study were to design and develop an open-circuit electromagnetic resonant skin patch sensor, characterize the fluid volume and resonant frequency relationship, and investigate the sensor's ability to measure limb hemodynamics and pulse volume waveform features. The skin patch was designed from an open-circuit electromagnetic resonant sensor comprised of a single baseline trace of copper configured into a square planar spiral which had a self-resonating response when excited by an external radio frequency sweep. Using a human arm phantom with a realistic vascular network, the sensor's performance to measure limb hemodynamics was evaluated. The sensor was able to measure pulsatile blood flow which registered as shifts in the sensor's resonant frequencies. The time-varying waveform pattern of the resonant frequency displayed a systolic upstroke, a systolic peak, a dicrotic notch, and a diastolic down stroke. The resonant frequency waveform features and peak systolic time were validated against ultrasound pulse wave Doppler. A statistical correlation analysis revealed a strong correlation () between the resonant sensor peak systolic time and the pulse wave Doppler peak systolic time. The sensor was able to detect pulsatile flow, identify hemodynamic waveform features, and measure heart rate with 98% accuracy. The open-circuit resonant sensor design leverages the architecture of a thin planar spiral which is passive (does not require batteries), robust and lightweight (does not have electrical components or electrical connections), and may be able to wirelessly monitor cardiovascular health and limb hemodynamics.

SIRRACT: An international randomized clinical trial of activity feedback during inpatient stroke rehabilitation enabled by wireless sensing

PubMed Central

Dorsch, Andrew K.; Thomas, Seth; Xu, Xiaoyu; Kaiser, William; Dobkin, Bruce H.

2014-01-01

Background Walking-related disability is the most frequent reason for inpatient stroke rehabilitation. Task-related practice is a critical component for improving patient outcomes. Objective To test the feasibility of providing quantitative feedback about daily walking performance and motivating greater skills practice via remote sensing. Methods In this phase III randomized, single blind clinical trial, patients participated in conventional therapies while wearing wireless sensors (tri-axial accelerometers) at both ankles. Activity-recognition algorithms calculated the speed, distance, and duration of walking bouts. Three times a week, therapists provided either feedback about performance on a 10-meter walk (speed-only) or walking speed feedback plus a review of walking activity recorded by the sensors (augmented). Primary outcomes at discharge included total daily walking time, derived from the sensors, and a timed 15-meter walk. Results Sixteen rehabilitation centers in 11 countries enrolled 135 participants over 15 months. Sensors recorded more than 1800 days of therapy, 37,000 individual walking bouts, and 2.5 million steps. No significant differences were found between the two feedback groups in daily walking time (15.1±13.1min vs. 16.6±14.3min, p=0.54) or 15-meter walking speed (0.93±0.47m/s vs. 0.91±0.53m/s, p=0.96). Remarkably, 30% of participants decreased their total daily walking time over their rehabilitation stay. Conclusions In this first trial of remote monitoring of inpatient stroke rehabilitation, augmented feedback beyond speed alone did not increase the time spent practicing or improve walking outcomes. Remarkably modest time was spent walking. Wireless sensing, however, allowed clinicians to audit skills practice and provided ground truth regarding changes in clinically important, mobility-related activities. PMID:25261154

A novel adaptive, real-time algorithm to detect gait events from wearable sensors.

PubMed

Chia Bejarano, Noelia; Ambrosini, Emilia; Pedrocchi, Alessandra; Ferrigno, Giancarlo; Monticone, Marco; Ferrante, Simona

2015-05-01

A real-time, adaptive algorithm based on two inertial and magnetic sensors placed on the shanks was developed for gait-event detection. For each leg, the algorithm detected the Initial Contact (IC), as the minimum of the flexion/extension angle, and the End Contact (EC) and the Mid-Swing (MS), as minimum and maximum of the angular velocity, respectively. The algorithm consisted of calibration, real-time detection, and step-by-step update. Data collected from 22 healthy subjects (21 to 85 years) walking at three self-selected speeds were used to validate the algorithm against the GaitRite system. Comparable levels of accuracy and significantly lower detection delays were achieved with respect to other published methods. The algorithm robustness was tested on ten healthy subjects performing sudden speed changes and on ten stroke subjects (43 to 89 years). For healthy subjects, F1-scores of 1 and mean detection delays lower than 14 ms were obtained. For stroke subjects, F1-scores of 0.998 and 0.944 were obtained for IC and EC, respectively, with mean detection delays always below 31 ms. The algorithm accurately detected gait events in real time from a heterogeneous dataset of gait patterns and paves the way for the design of closed-loop controllers for customized gait trainings and/or assistive devices.

Non-Invasive Electromagnetic Skin Patch Sensor to Measure Intracranial Fluid–Volume Shifts

PubMed Central

Griffith, Jacob; Cluff, Kim; Eckerman, Brandon; Aldrich, Jessica; Becker, Ryan; Moore-Jansen, Peer; Patterson, Jeremy

2018-01-01

Elevated intracranial fluid volume can drive intracranial pressure increases, which can potentially result in numerous neurological complications or death. This study’s focus was to develop a passive skin patch sensor for the head that would non-invasively measure cranial fluid volume shifts. The sensor consists of a single baseline component configured into a rectangular planar spiral with a self-resonant frequency response when impinged upon by external radio frequency sweeps. Fluid volume changes (10 mL increments) were detected through cranial bone using the sensor on a dry human skull model. Preliminary human tests utilized two sensors to determine feasibility of detecting fluid volume shifts in the complex environment of the human body. The correlation between fluid volume changes and shifts in the first resonance frequency using the dry human skull was classified as a second order polynomial with R2 = 0.97. During preliminary and secondary human tests, a ≈24 MHz and an average of ≈45.07 MHz shifts in the principal resonant frequency were measured respectively, corresponding to the induced cephalad bio-fluid shifts. This electromagnetic resonant sensor may provide a non-invasive method to monitor shifts in fluid volume and assist with medical scenarios including stroke, cerebral hemorrhage, concussion, or monitoring intracranial pressure. PMID:29596338

Correction of large amplitude wavefront aberrations

NASA Astrophysics Data System (ADS)

Cornelissen, S. A.; Bierden, P. A.; Bifano, T. G.; Webb, R. H.; Burns, S.; Pappas, S.

2005-12-01

Recently, a number of research groups around the world have developed ophthalmic instruments capable of in vivo diffraction limited imaging of the human retina. Adaptive optics was used in these systems to compensate for the optical aberrations of the eye and provide high contrast, high resolution images. Such compensation uses a wavefront sensor and a wavefront corrector (usually a deformable mirror) coordinated in a closed- loop control system that continuously works to counteract aberrations. While those experiments produced promising results, the deformable mirrors have had insufficient range of motion to permit full correction of the large amplitude aberrations of the eye expected in a normal population of human subjects. Other retinal imaging systems developed to date with MEMS (micro-electromechanical systems) DMs suffer similar limitations. This paper describes the design, manufacture and testing of a 6um stroke polysilicon surface micromachined deformable mirror that, coupled with an new optical method to double the effective stroke of the MEMS-DM, will permit diffraction-limited retinal imaging through dilated pupils in at least 90% of the human population. A novel optical design using spherical mirrors provides a double pass of the wavefront over the deformable mirror such that a 6um mirror displacement results in 12um of wavefront compensation which could correct for 24um of wavefront error. Details of this design are discussed. Testing of the effective wavefront modification was performed using a commercial wavefront sensor. Results are presented demonstrating improvement in the amplitude of wavefront control using an existing high degree of freedom MEMS deformable mirror.

Potent neuroprotection after stroke afforded by a double-knot spider-venom peptide that inhibits acid-sensing ion channel 1a

PubMed Central

Chassagnon, Irène R.; McCarthy, Claudia A.; Chin, Yanni K.-Y.; Pineda, Sandy S.; Mobli, Mehdi; Pham, Vi; De Silva, T. Michael; Lynch, Joseph W.; Widdop, Robert E.; Rash, Lachlan D.

2017-01-01

Stroke is the second-leading cause of death worldwide, yet there are no drugs available to protect the brain from stroke-induced neuronal injury. Acid-sensing ion channel 1a (ASIC1a) is the primary acid sensor in mammalian brain and a key mediator of acidosis-induced neuronal damage following cerebral ischemia. Genetic ablation and selective pharmacologic inhibition of ASIC1a reduces neuronal death following ischemic stroke in rodents. Here, we demonstrate that Hi1a, a disulfide-rich spider venom peptide, is highly neuroprotective in a focal model of ischemic stroke. Nuclear magnetic resonance structural studies reveal that Hi1a comprises two homologous inhibitor cystine knot domains separated by a short, structurally well-defined linker. In contrast with known ASIC1a inhibitors, Hi1a incompletely inhibits ASIC1a activation in a pH-independent and slowly reversible manner. Whole-cell, macropatch, and single-channel electrophysiological recordings indicate that Hi1a binds to and stabilizes the closed state of the channel, thereby impeding the transition into a conducting state. Intracerebroventricular administration to rats of a single small dose of Hi1a (2 ng/kg) up to 8 h after stroke induction by occlusion of the middle cerebral artery markedly reduced infarct size, and this correlated with improved neurological and motor function, as well as with preservation of neuronal architecture. Thus, Hi1a is a powerful pharmacological tool for probing the role of ASIC1a in acid-mediated neuronal injury and various neurological disorders, and a promising lead for the development of therapeutics to protect the brain from ischemic injury. PMID:28320941

On the behavior of return stroke current and the remotely detected electric field change waveform

NASA Astrophysics Data System (ADS)

Shao, Xuan-Min; Lay, Erin; Jacobson, Abram R.

2012-04-01

After accumulating a large number of remotely recorded negative return stroke electric field change waveforms, a subtle but persistent kink was found following the main return stroke peak by several microseconds. To understand the corresponding return stroke current properties behind the kink and the general return stroke radiation waveform, we analyze strokes occurring in triggered lightning flashes for which have been measured both the channel base current and simultaneous remote electric radiation field. In this study, the channel base current is assumed to propagate along the return stroke channel in a dispersive and lossy manner. The measured channel base current is band-pass filtered, and the higher-frequency component is assumed to attenuate faster than the lower-frequency component. The radiation electric field is computed for such a current behavior and is then propagated to distant sensors. It is found that such a return stroke model is capable of very closely reproducing the measured electric waveforms at multiple stations for the triggered return strokes, and such a model is considered applicable to the common behavior of the natural return stroke as well. On the basis of the analysis, a number of other observables are derived. The time-evolving current dispersion and attenuation compare well with previously reported optical observations. The observable speed tends to agree with optical and VHF observations. Line charge density that is removed or deposited by the return stroke is derived, and the implication of the charge density distribution on leader channel decay is discussed.

Triangulations of sprites relative to parent lighting near the Oklahoma Lightning Mapping Array

NASA Astrophysics Data System (ADS)

Lu, G.; Cummer, S. A.; Li, J.; Lyons, W. A.; Stanley, M. A.; Krehbiel, P. R.; Rison, W.; Thomas, R. J.; Weiss, S. A.; Beasley, W. H.; Bruning, E. C.; MacGorman, D. R.; Palivec, K.; Samaras, T. M.

2012-12-01

Temporal and spatial development of sprite-producing lightning flashes is examined with coordinated observations over an asymmetric mesoscale convective system on June 29, 2011 near the Oklahoma Lightning Mapping Array (OK-LMA). About 30 sprites were mutually observed from Bennett, Colorado and Hawley, Texas, allowing us to triangulate sprite formation in comparison with spatial/temporal development of the parent lightning. Complementary measurements of broadband (<1 Hz to ~300 kHz) radio frequency lightning signals are available from several magnetic sensors across the United States. Our analyses indicate that although sprite locations can be significantly offset horizontally (up to 70 km) from the parent ground stroke, they are usually laterally within 30 km of the in-cloud lightning activity during the 100 ms time interval prior to the sprite production. This is true for short-delayed sprites produced within 20 ms after a causative stroke, and long-delayed sprites appearing up to more than 200 ms after the stroke. Multiple sprites appearing as dancing/jumping events can be produced during one single flash either in a single lightning channel, through series of current surges superposed on a long and intense continuing current, or in multiple lightning channels through distinct ground strokes of the flash. The burst of continuous very-low-frequency/low-frequency lightning sferics commonly observed in association with sprites is linked to the horizontal progression of multiple negative leaders through positive charged regions of the cloud, which are typically centered at altitudes ~1-2 km (or more) above the freezing level.

Predicting efficacy of robot-aided rehabilitation in chronic stroke patients using an MRI-compatible robotic device.

PubMed

Sergi, Fabrizio; Krebs, Hermano Igo; Groissier, Benjamin; Rykman, Avrielle; Guglielmelli, Eugenio; Volpe, Bruce T; Schaechter, Judith D

2011-01-01

We are investigating the neural correlates of motor recovery promoted by robot-mediated therapy in chronic stroke. This pilot study asked whether efficacy of robot-aided motor rehabilitation in chronic stroke could be predicted by a change in functional connectivity within the sensorimotor network in response to a bout of motor rehabilitation. To address this question, two stroke patients participated in a functional connectivity MRI study pre and post a 12-week robot-aided motor rehabilitation program. Functional connectivity was evaluated during three consecutive scans before the rehabilitation program: resting-state; point-to-point reaching movements executed by the paretic upper extremity (UE) using a newly developed MRI-compatible sensorized passive manipulandum; resting-state. A single resting-state scan was conducted after the rehabilitation program. Before the program, UE movement reduced functional connectivity between the ipsilesional and contralesional primary motor cortex. Reduced interhemispheric functional connectivity persisted during the second resting-state scan relative to the first and during the resting-state scan after the rehabilitation program. Greater reduction in interhemispheric functional connectivity during the resting-state was associated with greater gains in UE motor function induced by the 12-week robotic therapy program. These findings suggest that greater reduction in interhemispheric functional connectivity in response to a bout of motor rehabilitation may predict greater efficacy of the full rehabilitation program.

Design and Test of a Closed-Loop FES System for Supporting Function of the Hemiparetic Hand Based on Automatic Detection using the Microsoft Kinect sensor.

PubMed

Simonsen, Daniel; Spaich, Erika G; Hansen, John; Andersen, Ole K

2016-10-26

This paper describes the design of a FES system automatically controlled in a closed loop using a Microsoft Kinect sensor, for assisting both cylindrical grasping and hand opening. The feasibility of the system was evaluated in real-time in stroke patients with hand function deficits. A hand function exercise was designed in which the subjects performed an arm and hand exercise in sitting position. The subject had to grasp one of two differently sized cylindrical objects and move it forward or backwards in the sagittal plane. This exercise was performed with each cylinder with and without FES support. Results showed that the stroke patients were able to perform up to 29% more successful grasps when they were assisted by FES. Moreover, the hand grasp-and-hold and hold-and-release durations were shorter for the smaller of the two cylinders. FES was appropriately timed in more than 95% of all trials indicating successful closed loop FES control. Future studies should incorporate options for assisting forward reaching in order to target a larger group of stroke patients.

Reliability and validity of bilateral ankle accelerometer algorithms for activity recognition and walking speed after stroke.

PubMed

Dobkin, Bruce H; Xu, Xiaoyu; Batalin, Maxim; Thomas, Seth; Kaiser, William

2011-08-01

Outcome measures of mobility for large stroke trials are limited to timed walks for short distances in a laboratory, step counters and ordinal scales of disability and quality of life. Continuous monitoring and outcome measurements of the type and quantity of activity in the community would provide direct data about daily performance, including compliance with exercise and skills practice during routine care and clinical trials. Twelve adults with impaired ambulation from hemiparetic stroke and 6 healthy controls wore triaxial accelerometers on their ankles. Walking speed for repeated outdoor walks was determined by machine-learning algorithms and compared to a stopwatch calculation of speed for distances not known to the algorithm. The reliability of recognizing walking, exercise, and cycling by the algorithms was compared to activity logs. A high correlation was found between stopwatch-measured outdoor walking speed and algorithm-calculated speed (Pearson coefficient, 0.98; P=0.001) and for repeated measures of algorithm-derived walking speed (P=0.01). Bouts of walking >5 steps, variations in walking speed, cycling, stair climbing, and leg exercises were correctly identified during a day in the community. Compared to healthy subjects, those with stroke were, as expected, more sedentary and slower, and their gait revealed high paretic-to-unaffected leg swing ratios. Test-retest reliability and concurrent and construct validity are high for activity pattern-recognition Bayesian algorithms developed from inertial sensors. This ratio scale data can provide real-world monitoring and outcome measurements of lower extremity activities and walking speed for stroke and rehabilitation studies.

A pilot clinical trial on a Variable Automated Speed and Sensing Treadmill (VASST) for hemiparetic gait rehabilitation in stroke patients.

PubMed

Chua, Karen S G; Chee, Johnny; Wong, Chin J; Lim, Pang H; Lim, Wei S; Hoo, Chuan M; Ong, Wai S; Shen, Mira L; Yu, Wei S

2015-01-01

Impairments in walking speed and capacity are common problems after stroke which may benefit from treadmill training. However, standard treadmills, are unable to adapt to the slower walking speeds of stroke survivors and are unable to automate training progression. This study tests a Variable Automated Speed and Sensing Treadmill (VASST) using a standard clinical protocol. VASST is a semi-automated treadmill with multiple sensors and micro controllers, including wireless control to reposition a fall-prevention harness, variable pre-programmed exercise parameters and laser beam foot sensors positioned on the belt to detect subject's foot positions. An open-label study with assessor blinding was conducted in 10 community-dwelling chronic hemiplegic patients who could ambulate at least 0.1 m/s. Interventions included physiotherapist-supervised training on VASST for 60 min three times per week for 4 weeks (total 12 h). Outcome measures of gait speed, quantity, balance, and adverse events were assessed at baseline, 2, 4, and 8 weeks. Ten subjects (8 males, mean age 55.5 years, 2.1 years post stroke) completed VASST training. Mean 10-m walk test speed was 0.69 m/s (SD = 0.29) and mean 6-min walk test distance was 178.3 m (84.0). After 4 weeks of training, 70% had significant positive gains in gait speed (0.06 m/s, SD = 0.08 m/s, P = 0.037); and 90% improved in walking distance. (54.3 m, SD = 30.9 m, P = 0.005). There were no adverse events. This preliminary study demonstrates the initial feasibility and short-term efficacy of VASST for walking speed and distance for people with chronic post-stroke hemiplegia.

A haptic-robotic platform for upper-limb reaching stroke therapy: Preliminary design and evaluation results

PubMed Central

Lam, Paul; Hebert, Debbie; Boger, Jennifer; Lacheray, Hervé; Gardner, Don; Apkarian, Jacob; Mihailidis, Alex

2008-01-01

Background It has been shown that intense training can significantly improve post-stroke upper-limb functionality. However, opportunities for stroke survivors to practice rehabilitation exercises can be limited because of the finite availability of therapists and equipment. This paper presents a haptic-enabled exercise platform intended to assist therapists and moderate-level stroke survivors perform upper-limb reaching motion therapy. This work extends on existing knowledge by presenting: 1) an anthropometrically-inspired design that maximizes elbow and shoulder range of motions during exercise; 2) an unobtrusive upper body postural sensing system; and 3) a vibratory elbow stimulation device to encourage muscle movement. Methods A multi-disciplinary team of professionals were involved in identifying the rehabilitation needs of stroke survivors incorporating these into a prototype device. The prototype system consisted of an exercise device, postural sensors, and a elbow stimulation to encourage the reaching movement. Eight experienced physical and occupational therapists participated in a pilot study exploring the usability of the prototype. Each therapist attended two sessions of one hour each to test and evaluate the proposed system. Feedback about the device was obtained through an administered questionnaire and combined with quantitative data. Results Seven of the nine questions regarding the haptic exercise device scored higher than 3.0 (somewhat good) out of 4.0 (good). The postural sensors detected 93 of 96 (97%) therapist-simulated abnormal postures and correctly ignored 90 of 96 (94%) of normal postures. The elbow stimulation device had a score lower than 2.5 (neutral) for all aspects that were surveyed, however the therapists felt the rehabilitation system was sufficient for use without the elbow stimulation device. Conclusion All eight therapists felt the exercise platform could be a good tool to use in upper-limb rehabilitation as the prototype was considered to be generally well designed and capable of delivering reaching task therapy. The next stage of this project is to proceed to clinical trials with stroke patients. PMID:18498641

Deletion or Inhibition of the Oxygen Sensor PHD1 Protects against Ischemic Stroke via Reprogramming of Neuronal Metabolism.

PubMed

Quaegebeur, Annelies; Segura, Inmaculada; Schmieder, Roberta; Verdegem, Dries; Decimo, Ilaria; Bifari, Francesco; Dresselaers, Tom; Eelen, Guy; Ghosh, Debapriva; Davidson, Shawn M; Schoors, Sandra; Broekaert, Dorien; Cruys, Bert; Govaerts, Kristof; De Legher, Carla; Bouché, Ann; Schoonjans, Luc; Ramer, Matt S; Hung, Gene; Bossaert, Goele; Cleveland, Don W; Himmelreich, Uwe; Voets, Thomas; Lemmens, Robin; Bennett, C Frank; Robberecht, Wim; De Bock, Katrien; Dewerchin, Mieke; Ghesquière, Bart; Fendt, Sarah-Maria; Carmeliet, Peter

2016-02-09

The oxygen-sensing prolyl hydroxylase domain proteins (PHDs) regulate cellular metabolism, but their role in neuronal metabolism during stroke is unknown. Here we report that PHD1 deficiency provides neuroprotection in a murine model of permanent brain ischemia. This was not due to an increased collateral vessel network. Instead, PHD1(-/-) neurons were protected against oxygen-nutrient deprivation by reprogramming glucose metabolism. Indeed, PHD1(-/-) neurons enhanced glucose flux through the oxidative pentose phosphate pathway by diverting glucose away from glycolysis. As a result, PHD1(-/-) neurons increased their redox buffering capacity to scavenge oxygen radicals in ischemia. Intracerebroventricular injection of PHD1-antisense oligonucleotides reduced the cerebral infarct size and neurological deficits following stroke. These data identify PHD1 as a regulator of neuronal metabolism and a potential therapeutic target in ischemic stroke. Copyright © 2016 Elsevier Inc. All rights reserved.

Feasibility of a Customized, In-Home, Game-Based Stroke Exercise Program Using the Microsoft Kinect® Sensor.

PubMed

Proffitt, Rachel; Lange, Belinda

2015-01-01

The objective of this study was to determine the feasibility of a 6-week, game-based, in-home telerehabilitation exercise program using the Microsoft Kinect® for individuals with chronic stroke. Four participants with chronic stroke completed the intervention based on games designed with the customized Mystic Isle software. The games were tailored to each participant's specific rehabilitation needs to facilitate the attainment of individualized goals determined through the Canadian Occupational Performance Measure. Likert scale questionnaires assessed the feasibility and utility of the game-based intervention. Supplementary clinical outcome data were collected. All participants played the games with moderately high enjoyment. Participant feedback helped identify barriers to use (especially, limited free time) and possible improvements. An in-home, customized, virtual reality game intervention to provide rehabilitative exercises for persons with chronic stroke is practicable. However, future studies are necessary to determine the intervention's impact on participant function, activity, and involvement.

DELETION OR INHIBITION OF THE OXYGEN SENSOR PHD1 PROTECTS AGAINST ISCHEMIC STROKE VIA REPROGRAMMING OF NEURONAL METABOLISM

PubMed Central

Quaegebeur, Annelies; Segura, Inmaculada; Schmieder, Roberta; Verdegem, Dries; Decimo, Ilaria; Bifari, Francesco; Dresselaers, Tom; Eelen, Guy; Ghosh, Debapriva; Schoors, Sandra; Janaki Raman, Sudha Rani; Cruys, Bert; Govaerts, Kristof; De Legher, Carla; Bouché, Ann; Schoonjans, Luc; Ramer, Matt S.; Hung, Gene; Bossaert, Goele; Cleveland, Don W.; Himmelreich, Uwe; Voets, Thomas; Lemmens, Robin; Bennett, C. Frank; Robberecht, Wim; De Bock, Katrien; Dewerchin, Mieke; Fendt, Sarah-Maria; Ghesquière, Bart; Carmeliet, Peter

2016-01-01

Summary The oxygen-sensing prolyl hydroxylase domain proteins (PHDs) regulate cellular metabolism, but their role in neuronal metabolism during stroke is unknown. Here we report that PHD1 deficiency provides neuroprotection in a murine model of permanent brain ischemia. This was not due to an increased collateral vessel network, nor to enhanced neurotrophin expression. Instead, PHD1−/− neurons were protected against oxygen-nutrient deprivation by reprogramming glucose metabolism. Indeed, PHD1−/− neurons enhanced glucose flux through the oxidative pentose phosphate pathway by diverting glucose from glycolysis. As a result, PHD1−/− neurons increased their redox buffering capacity to scavenge oxygen radicals in ischemia. Intracerebroventricular injection of PHD1-antisense oligonucleotides reduced the cerebral infarct size and neurological deficits following stroke. These data identify PHD1 as a novel regulator of neuronal metabolism and a potential therapeutic target in ischemic stroke. PMID:26774962

Pulse Oximeter Plethysmographic Waveform Changes in Awake, Spontaneously Breathing, Hypovolemic Volunteers

DTIC Science & Technology

2011-02-01

Methods of Measurement All subjects were instrumented with 3 Nonin pulse oximeter sensors ( Nonin Medical, Plymouth, MN; OEM III module, 16-bit data...ring finger of the left hand. Unlike standard pulse oximeters that have autocalibration capability, the Nonin pulse oximeter did not alter the raw...stroke volume and are therefore presented as percentage change from baseline levels. The PPG and Spo2 values from the Nonin pulse oxime- ter sensors were

Network of movement and proximity sensors for monitoring upper-extremity motor activity after stroke: proof of principle.

PubMed

Sokal, Brad; Uswatte, Gitendra; Barman, Joydip; Brewer, Michael; Byrom, Ezekiel; Latten, Jessica; Joseph, Jeethu; Serafim, Camila; Ghaffari, Touraj; Sarkar, Nilanjan

2014-03-01

To test the convergent validity of an objective method, Sensor-Enabled Radio-frequency Identification System for Monitoring Arm Activity (SERSMAA), that distinguishes between functional and nonfunctional activity. Cross-sectional study. Laboratory. Participants (N=25) were ≥0.2 years poststroke (median, 9) with a wide range of severity of upper-extremity hemiparesis. Not applicable. After stroke, laboratory tests of the motor capacity of the more-affected arm poorly predict spontaneous use of that arm in daily life. However, available subjective methods for measuring everyday arm use are vulnerable to self-report biases, whereas available objective methods only provide information on the amount of activity without regard to its relation with function. The SERSMAA consists of a proximity-sensor receiver on the more-affected arm and multiple units placed on objects. Functional activity is signaled when the more-affected arm is close to an object that is moved. Participants were videotaped during a laboratory simulation of an everyday activity, that is, setting a table with cups, bowls, and plates instrumented with transmitters. Observers independently coded the videos in 2-second blocks with a validated system for classifying more-affected arm activity. There was a strong correlation (r=.87, P<.001) between time that the more-affected arm was used for handling objects according to the SERSMAA and functional activity according to the observers. The convergent validity of SERSMAA for measuring more-affected arm functional activity after stroke was supported in a simulation of everyday activity. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Summary of 2011 Direct and Nearby Lightning Strikes to Launch Complex 39B, Kennedy Space Center, Florida

NASA Technical Reports Server (NTRS)

Mata, C.T.; Mata, A.G.

2012-01-01

A Lightning Protection System (LPS) was designed and built at Launch Complex 39B (LC39B), at the Kennedy Space Center (KSC), Florida in 2009. This LPS was instrumented with comprehensive meteorological and lightning data acquisition systems that were deployed from late 2010 until mid 2011. The first direct strikes to the LPS were recorded in March of 2011, when a limited number of sensors had been activated. The lightning instrumentation system detected a total of 70 nearby strokes and 19 direct strokes to the LPS, 2 of the 19 direct strokes to the LPS had two simultaneous ground attachment points (in both instances one channel terminated on the LPS and the other on the nearby ground). Additionally, there are more unaccounted nearby strokes seen on video records for which limited data was acquired either due to the distance of the stroke or the settings of the data acquisition system. Instrumentation deployment chronological milestones, a summary of lightning strikes (direct and nearby), high speed video frames, downconductor currents, and dH/dt and dE/dt typical waveforms for direct and nearby strokes are presented.

Objective fall risk detection in stroke survivors using wearable sensor technology: a feasibility study.

PubMed

Taylor-Piliae, Ruth E; Mohler, M Jane; Najafi, Bijan; Coull, Bruce M

2016-12-01

Stroke survivors often have persistent neural deficits related to motor function and sensation, which increase their risk of falling, most of which occurs at home or in community settings. The use of wearable technology to monitor fall risk and gait in stroke survivors may prove useful in enhancing recovery and/or preventing injuries. Determine the feasibility of using wearable technology (PAMSys™) to objectively monitor fall risk and gait in home and community settings in stroke survivors. In this feasibility study, we used the PAMSys to identify fall risk indicators (postural transitions: duration in seconds, and number of unsuccessful attempts), and gait (steps, speed, duration) for 48 hours during usual daily activities in stroke survivors (n = 10) compared to age-matched controls (n = 10). A questionnaire assessed device acceptability. Stroke survivors mean age was 70 ± 8 years old, were mainly Caucasian (60%) women (70%), and not significantly different than the age-matched controls (all P-values >0.20). Stroke survivors (100%) reported that the device was comfortable to wear, didn't interfere with everyday activities, and were willing to wear it for another 48 hours. None reported any difficulty with the device while sleeping, removing/putting back on for showering or changing clothes. When compared to controls, stroke survivors had significantly worse fall risk indicators and walked less (P < 0.05). Stroke survivors reported high acceptability of 48 hours of continuous PAMSys monitoring. The use of in-home wearable technology may prove useful in monitoring fall risk and gait in stroke survivors, potentially enhancing recovery.

Solar powered automobile automation for heatstroke prevention

NASA Astrophysics Data System (ADS)

Singh, Navtej Swaroop; Sharma, Ishan; Jangid, Santosh

2016-03-01

Heatstroke inside a car has been critical problem in every part of the world. Non-exertional heat stroke results from exposure to a high environmental temperature. Exertional heat stroke happens from strenuous exercise. This paper presents a solution for this fatal problem and proposes an embedded solution, which is cost effective and shows the feasibility in implementation. The proposed system consists of information sharing platform, interfacing of sensors, Global System Mobile (GSM), real time monitoring system and the system is powered by the solar panel. The system has been simulated and tested with experimental setup.

Gait switches in deep-diving beaked whales: biomechanical strategies for long-duration dives.

PubMed

Martín López, Lucía Martina; Miller, Patrick J O; Aguilar de Soto, Natacha; Johnson, Mark

2015-05-01

Diving animals modulate their swimming gaits to promote locomotor efficiency and so enable longer, more productive dives. Beaked whales perform extremely long and deep foraging dives that probably exceed aerobic capacities for some species. Here, we use biomechanical data from suction-cup tags attached to three species of beaked whales (Mesoplodon densirostris, N=10; Ziphius cavirostris, N=9; and Hyperoodon ampullatus, N=2) to characterize their swimming gaits. In addition to continuous stroking and stroke-and-glide gaits described for other diving mammals, all whales produced occasional fluke-strokes with distinctly larger dorso-ventral acceleration, which we termed 'type-B' strokes. These high-power strokes occurred almost exclusively during deep dive ascents as part of a novel mixed gait. To quantify body rotations and specific acceleration generated during strokes we adapted a kinematic method combining data from two sensors in the tag. Body rotations estimated with high-rate magnetometer data were subtracted from accelerometer data to estimate the resulting surge and heave accelerations. Using this method, we show that stroke duration, rotation angle and acceleration were bi-modal for these species, with B-strokes having 76% of the duration, 52% larger body rotation and four times more surge than normal strokes. The additional acceleration of B-strokes did not lead to faster ascents, but rather enabled brief glides, which may improve the overall efficiency of this gait. Their occurrence towards the end of long dives leads us to propose that B-strokes may recruit fast-twitch fibres that comprise ∼80% of swimming muscles in Blainville's beaked whales, thus prolonging foraging time at depth. © 2015. Published by The Company of Biologists Ltd.

EMG finger movement classification based on ANFIS

NASA Astrophysics Data System (ADS)

Caesarendra, W.; Tjahjowidodo, T.; Nico, Y.; Wahyudati, S.; Nurhasanah, L.

2018-04-01

An increase number of people suffering from stroke has impact to the rapid development of finger hand exoskeleton to enable an automatic physical therapy. Prior to the development of finger exoskeleton, a research topic yet important i.e. machine learning of finger gestures classification is conducted. This paper presents a study on EMG signal classification of 5 finger gestures as a preliminary study toward the finger exoskeleton design and development in Indonesia. The EMG signals of 5 finger gestures were acquired using Myo EMG sensor. The EMG signal features were extracted and reduced using PCA. The ANFIS based learning is used to classify reduced features of 5 finger gestures. The result shows that the classification of finger gestures is less than the classification of 7 hand gestures.

Development and preliminary evaluation of a novel low cost VR-based upper limb stroke rehabilitation platform using Wii technology.

PubMed

Tsekleves, Emmanuel; Paraskevopoulos, Ioannis Theoklitos; Warland, Alyson; Kilbride, Cherry

2016-01-01

This paper proposes a novel system (using the Nintendo Wii remote) that offers customised, non-immersive, virtual reality-based, upper-limb stroke rehabilitation and reports on promising preliminary findings with stroke survivors. The system novelty lies in the high accuracy of the full kinematic tracking of the upper limb movement in real-time, offering strong personal connection between the stroke survivor and a virtual character when executing therapist prescribed adjustable exercises/games. It allows the therapist to monitor patient performance and to individually calibrate the system in terms of range of movement, speed and duration. The system was tested for acceptability with three stroke survivors with differing levels of disability. Participants reported an overwhelming connection with the system and avatar. A two-week, single case study with a long-term stroke survivor showed positive changes in all four outcome measures employed, with the participant reporting better wrist control and greater functional use. Activities, which were deemed too challenging or too easy were associated with lower scores of enjoyment/motivation, highlighting the need for activities to be individually calibrated. Given the preliminary findings, it would be beneficial to extend the case study in terms of duration and participants and to conduct an acceptability and feasibility study with community dwelling survivors. Implications for Rehabilitation Low-cost, off-the-shelf game sensors, such as the Nintendo Wii remote, are acceptable by stroke survivors as an add-on to upper limb stroke rehabilitation but have to be bespoked to provide high-fidelity and real-time kinematic tracking of the arm movement. Providing therapists with real-time and remote monitoring of the quality of the movement and not just the amount of practice, is imperative and most critical for getting a better understanding of each patient and administering the right amount and type of exercise. The ability to translate therapeutic arm movement into individually calibrated exercises and games, allows accommodation of the wide range of movement difficulties seen after stroke and the ability to adjust these activities (in terms of speed, range of movement and duration) will aid motivation and adherence - key issues in rehabilitation. With increasing pressures on resources and the move to more community-based rehabilitation, the proposed system has the potential for promoting the intensity of practice necessary for recovery in both community and acute settings.

Head ballistocardiogram based on wireless multi-location sensors.

PubMed

Onizuka, Kohei; Sodini, Charles G

2015-08-01

Recently a wearable BCG monitoring technique based on an accelerometer worn at the ear was demonstrated to replace a conventional bulky BCG acquisition system. In this work, a multi-location wireless vital signs monitor was developed, and at least two common acceleration vectors correlating to sitting-BCG were found in the supine position by using head PPG signal as a reference for eight healthy human subjects. The head side amplitude in the supine position is roughly proportional to the sitting amplitude that is in turn proportional to the stroke volume. Signal processing techniques to identify J-waves in a subject having small amplitude was also developed based on the two common vectors at the head side and top.

Examining impairment of adaptive compensation for stabilizing motor repetitions in stroke survivors.

PubMed

Kim, Yushin; Koh, Kyung; Yoon, BumChul; Kim, Woo-Sub; Shin, Joon-Ho; Park, Hyung-Soon; Shim, Jae Kun

2017-12-01

The hand, one of the most versatile but mechanically redundant parts of the human body, suffers more and longer than other body parts after stroke. One of the rehabilitation paradigms, task-oriented rehabilitation, encourages motor repeatability, the ability to produce similar motor performance over repetitions through compensatory strategies while taking advantage of the motor system's redundancy. The previous studies showed that stroke survivors inconsistently performed a given motor task with limited motor solutions. We hypothesized that stroke survivors would exhibit deficits in motor repeatability and adaptive compensation compared to healthy controls in during repetitive force-pulse (RFP) production tasks using multiple fingers. Seventeen hemiparetic stroke survivors and seven healthy controls were asked to repeatedly press force sensors as fast as possible using the four fingers of each hand. The hierarchical variability decomposition model was employed to compute motor repeatability and adaptive compensation across finger-force impulses, respectively. Stroke survivors showed decreased repeatability and adaptive compensation of force impulses between individual fingers as compared to the control (p < 0.05). The stroke survivors also showed decreased pulse frequency and greater peak-to-peak time variance than the control (p < 0.05). Force-related variables, such as mean peak force and peak force interval variability, demonstrated no significant difference between groups. Our findings indicate that stroke-induced brain injury negatively affects their ability to exploit their redundant or abundant motor system in an RFP task.

Feasibility of a Customized, In-Home, Game-Based Stroke Exercise Program Using the Microsoft Kinect® Sensor

PubMed Central

PROFFITT, RACHEL; LANGE, BELINDA

2015-01-01

The objective of this study was to determine the feasibility of a 6-week, game-based, in-home telerehabilitation exercise program using the Microsoft Kinect® for individuals with chronic stroke. Four participants with chronic stroke completed the intervention based on games designed with the customized Mystic Isle software. The games were tailored to each participant’s specific rehabilitation needs to facilitate the attainment of individualized goals determined through the Canadian Occupational Performance Measure. Likert scale questionnaires assessed the feasibility and utility of the game-based intervention. Supplementary clinical outcome data were collected. All participants played the games with moderately high enjoyment. Participant feedback helped identify barriers to use (especially, limited free time) and possible improvements. An in-home, customized, virtual reality game intervention to provide rehabilitative exercises for persons with chronic stroke is practicable. However, future studies are necessary to determine the intervention’s impact on participant function, activity, and involvement. PMID:27563384

Biosensors for brain trauma and dual laser doppler flowmetry: enoxaparin simultaneously reduces stroke-induced dopamine and blood flow while enhancing serotonin and blood flow in motor neurons of brain, in vivo.

PubMed

Broderick, Patricia A; Kolodny, Edwin H

2011-01-01

Neuromolecular Imaging (NMI) based on adsorptive electrochemistry, combined with Dual Laser Doppler Flowmetry (LDF) is presented herein to investigate the brain neurochemistry affected by enoxaparin (Lovenox(®)), an antiplatelet/antithrombotic medication for stroke victims. NMI with miniature biosensors enables neurotransmitter and neuropeptide (NT) imaging; each NT is imaged with a response time in milliseconds. A semiderivative electronic reduction circuit images several NT's selectively and separately within a response time of minutes. Spatial resolution of NMI biosensors is in the range of nanomicrons and electrochemically-induced current ranges are in pico- and nano-amperes. Simultaneously with NMI, the LDF technology presented herein operates on line by illuminating the living brain, in this example, in dorso-striatal neuroanatomic substrates via a laser sensor with low power laser light containing optical fiber light guides. NMI biotechnology with BRODERICK PROBE(®) biosensors has a distinct advantage over conventional electrochemical methodologies both in novelty of biosensor formulations and on-line imaging capabilities in the biosensor field. NMI with unique biocompatible biosensors precisely images NT in the body, blood and brain of animals and humans using characteristic experimentally derived half-wave potentials driven by oxidative electron transfer. Enoxaparin is a first line clinical treatment prescribed to halt the progression of acute ischemic stroke (AIS). In the present studies, BRODERICK PROBE(®) laurate biosensors and LDF laser sensors are placed in dorsal striatum (DStr) dopaminergic motor neurons in basal ganglia of brain in living animals; basal ganglia influence movement disorders such as those correlated with AIS. The purpose of these studies is to understand what is happening in brain neurochemistry and cerebral blood perfusion after causal AIS by middle cerebral artery occlusion in vivo as well as to understand consequent enoxaparin and reperfusion effects actually while enoxaparin is inhibiting blood clots to alleviate AIS symptomatology. This research is directly correlated with the medical and clinical needs of stroke victims. The data are clinically relevant, not only to movement dysfunction but also to the depressive mood that stroke patients often endure. These are the first studies to image brain neurotransmitters while any stroke medications, such as anti-platelet/anti-thrombotic and/or anti-glycoprotein are working in organ systems to alleviate the debilitating consequences of brain trauma and stroke/brain attacks.

Biosensors for Brain Trauma and Dual Laser Doppler Flowmetry: Enoxaparin Simultaneously Reduces Stroke-Induced Dopamine and Blood Flow while Enhancing Serotonin and Blood Flow in Motor Neurons of Brain, In Vivo

PubMed Central

Broderick, Patricia A.; Kolodny, Edwin H.

2011-01-01

Neuromolecular Imaging (NMI) based on adsorptive electrochemistry, combined with Dual Laser Doppler Flowmetry (LDF) is presented herein to investigate the brain neurochemistry affected by enoxaparin (Lovenox®), an antiplatelet/antithrombotic medication for stroke victims. NMI with miniature biosensors enables neurotransmitter and neuropeptide (NT) imaging; each NT is imaged with a response time in milliseconds. A semiderivative electronic reduction circuit images several NT’s selectively and separately within a response time of minutes. Spatial resolution of NMI biosensors is in the range of nanomicrons and electrochemically-induced current ranges are in pico- and nano-amperes. Simultaneously with NMI, the LDF technology presented herein operates on line by illuminating the living brain, in this example, in dorso-striatal neuroanatomic substrates via a laser sensor with low power laser light containing optical fiber light guides. NMI biotechnology with BRODERICK PROBE® biosensors has a distinct advantage over conventional electrochemical methodologies both in novelty of biosensor formulations and on-line imaging capabilities in the biosensor field. NMI with unique biocompatible biosensors precisely images NT in the body, blood and brain of animals and humans using characteristic experimentally derived half-wave potentials driven by oxidative electron transfer. Enoxaparin is a first line clinical treatment prescribed to halt the progression of acute ischemic stroke (AIS). In the present studies, BRODERICK PROBE® laurate biosensors and LDF laser sensors are placed in dorsal striatum (DStr) dopaminergic motor neurons in basal ganglia of brain in living animals; basal ganglia influence movement disorders such as those correlated with AIS. The purpose of these studies is to understand what is happening in brain neurochemistry and cerebral blood perfusion after causal AIS by middle cerebral artery occlusion in vivo as well as to understand consequent enoxaparin and reperfusion effects actually while enoxaparin is inhibiting blood clots to alleviate AIS symptomatology. This research is directly correlated with the medical and clinical needs of stroke victims. The data are clinically relevant, not only to movement dysfunction but also to the depressive mood that stroke patients often endure. These are the first studies to image brain neurotransmitters while any stroke medications, such as anti-platelet/anti-thrombotic and/or anti-glycoprotein are working in organ systems to alleviate the debilitating consequences of brain trauma and stroke/brain attacks. PMID:22346571

Dynamic Measurement of Extra Long Stroke Cylinder in the Pneumatic System

NASA Astrophysics Data System (ADS)

Chang, Ho; Lan, Chou-wei; Chen, Liang-Chia

2006-10-01

This paper sets up the measure and control system of the dynamic characteristics of the extra long stroke cylinder. In the different types of the control conditions (e.g. different control law, operating pressure and direct control valves), using the measure and control system to measure the relation between the pressure and the velocity of the motion of the long stroke cylinder and to observe the stick slip phenomenon of the motion of the long stroke cylinder. In the innovate measurement system, two pressure sensors are set on the long stroke cylinder to measure the difference of the pressure between the inlet and the exhaust of the long stroke cylinder. In additions, a draw line encoder is set on the system to measure the position and the velocity of the motion of the long stroke cylinder. The measuring data of the measure system is transferred to the computer via A/D interface card and counter card, and Home-made program of Haptic Interface Device is used to control the system, saving the data of the motion of the long stroke cylinder. The system uses different types of direction control valve to control the motion of the long stroke cylinder and compares the difference of the motion of the long stroke cylinder. The results show that the motion of the cylinder that pauses in the middle of the cylinder stroke and causes the stick slip phenomenon is more violent than the stick slip phenomenon in other position. When the length of the pause time reaches the some range, the acceleration of the motion of the cylinder will be rised substantially. This paper not only focuses on the testing method of the dynamic characteristics of the motion of the long stroke cylinder, but also includes the analysis of the dynamic characteristics of the motion of the long stroke cylinder. It provides the data of the dynamic characteristics of the motion of the long stroke cylinder to improve and design the pneumatic system of the long stroke cylinder.

Analysis of electrical transients created by lightning

NASA Technical Reports Server (NTRS)

Nanevicz, J. E.; Vance, E. F.

1980-01-01

A series of flight tests was conducted using a specially-instrumented NASA Learjet to study the electrical transients created on an aircraft by nearby lightning. The instrumentation included provisions for the time-domain and frequency-domain recording of the electrical signals induced in sensors located both on the exterior and on the interior of the aircraft. The design and calibration of the sensors and associated measuring systems is described together with the results of the flight test measurements. The results indicate that the concept of providing instrumentation to follow the lightning signal from propagation field, to aircraft skin current, to current on interior wiring is basically sound. The results of the measurement indicate that the high frequency signals associated with lightning stroke precursor activity are important in generating electromagnetic noise on the interior of the aircraft. Indeed, the signals produced by the precursors are often of higher amplitude and of longer duration that the pulse produced by the main return stroke.

Direct observation of the myosin Va recovery stroke that contributes to unidirectional stepping along actin.

PubMed

Shiroguchi, Katsuyuki; Chin, Harvey F; Hannemann, Diane E; Muneyuki, Eiro; De La Cruz, Enrique M; Kinosita, Kazuhiko

2011-04-01

Myosins are ATP-driven linear molecular motors that work as cellular force generators, transporters, and force sensors. These functions are driven by large-scale nucleotide-dependent conformational changes, termed "strokes"; the "power stroke" is the force-generating swinging of the myosin light chain-binding "neck" domain relative to the motor domain "head" while bound to actin; the "recovery stroke" is the necessary initial motion that primes, or "cocks," myosin while detached from actin. Myosin Va is a processive dimer that steps unidirectionally along actin following a "hand over hand" mechanism in which the trailing head detaches and steps forward ∼72 nm. Despite large rotational Brownian motion of the detached head about a free joint adjoining the two necks, unidirectional stepping is achieved, in part by the power stroke of the attached head that moves the joint forward. However, the power stroke alone cannot fully account for preferential forward site binding since the orientation and angle stability of the detached head, which is determined by the properties of the recovery stroke, dictate actin binding site accessibility. Here, we directly observe the recovery stroke dynamics and fluctuations of myosin Va using a novel, transient caged ATP-controlling system that maintains constant ATP levels through stepwise UV-pulse sequences of varying intensity. We immobilized the neck of monomeric myosin Va on a surface and observed real time motions of bead(s) attached site-specifically to the head. ATP induces a transient swing of the neck to the post-recovery stroke conformation, where it remains for ∼40 s, until ATP hydrolysis products are released. Angle distributions indicate that the post-recovery stroke conformation is stabilized by ≥ 5 k(B)T of energy. The high kinetic and energetic stability of the post-recovery stroke conformation favors preferential binding of the detached head to a forward site 72 nm away. Thus, the recovery stroke contributes to unidirectional stepping of myosin Va.

Optical power and energy radiated by natural lightning

NASA Astrophysics Data System (ADS)

Quick, Mason G.; Krider, E. Philip

2013-02-01

Calibrated measurements of the visible and near-infrared radiation produced by both negative and positive cloud-to-ground (CG) lightning strokes have been made at distances of 5 to 32 km in southern Arizona (AZ) and the central Great Plains using a photodiode sensor with a flat spectral response between 0.4 and 1.0 µm. Time-correlated video images (60 fps) of the channel development provided information about the types of strokes that were detected and reports from the U.S. National Lightning Detection Network indicated their locations, polarities, and estimates of their peak current. In our sample of negative strokes that were suitable for analysis, there were 23 first (or only) strokes (FS), 19 subsequent strokes that created new ground contacts (NGC), and 101 subsequent strokes that re-illuminated a preexisting channel (PEC). We also analyzed 10 positive strokes (in nine flashes), and 73 of the larger impulses that were radiated by intracloud discharges (CPs). Assuming that these events can be approximated as isotropic sources and that the effects of atmospheric extinction are negligible, the peak optical power (Po), total optical energy (Eo), and characteristic widths of the sources (tcw = Eo/Po) have been computed. Median values of Po for negative FS, NGC, and PEC strokes were 1.8 × 1010 W, 1.1 × 1010 W, and 4.4 × 109 W, respectively. Median values of Eo were 3.6 × 106 J, 3.5 × 106 J, and 1.2 × 106 J, respectively. The median characteristic widths of negative FS, NGC, and PEC strokes were 229 µs, 244 µs, and 283 µs, respectively. Positive CG strokes produced a median Po, Eo, and tcw of 1.9 × 1010 W, 9.3 × 106 J, and 497 µs, respectively. Estimates of the space-and-time-average power per unit length (ℓo) in the lower portion of negative FS, NGC, and PEC channels had medians of 2.8 × 106 W/m, 3.2 × 106 W/m, and 1.4 × 106 W/m, respectively, and the median ℓo for four positive strokes was 8.8 × 106 W/m. Median values for the estimated peak electromagnetic power (PEM) radiated at early times in the strokes are 2.0 × 109 W, 2.5 × 109 W, 1.0 × 109 W, and 9.1 × 109 W for FS, NGC, PEC and positive strokes, respectively. CP events produced a median Po, Eo, and tcw of 2.0 × 109 W, 0.7 × 106 J, and 311 µs, respectively, and are in good agreement with aircraft and satellite measurements. The values of Po, Eo, and ℓo for negative CG strokes in AZ are significantly larger than prior measurements in Florida, likely because there is less atmospheric extinction in our dataset, and due to extinction, all the above values of Po, Eo, and ℓo are lower limits at the source.

Manual physical balance assistance of therapists during gait training of stroke survivors: characteristics and predicting the timing.

PubMed

Haarman, Juliet A M; Maartens, Erik; van der Kooij, Herman; Buurke, Jaap H; Reenalda, Jasper; Rietman, Johan S

2017-12-02

During gait training, physical therapists continuously supervise stroke survivors and provide physical support to their pelvis when they judge that the patient is unable to keep his balance. This paper is the first in providing quantitative data about the corrective forces that therapists use during gait training. It is assumed that changes in the acceleration of a patient's COM are a good predictor for therapeutic balance assistance during the training sessions Therefore, this paper provides a method that predicts the timing of therapeutic balance assistance, based on acceleration data of the sacrum. Eight sub-acute stroke survivors and seven therapists were included in this study. Patients were asked to perform straight line walking as well as slalom walking in a conventional training setting. Acceleration of the sacrum was captured by an Inertial Magnetic Measurement Unit. Balance-assisting corrective forces applied by the therapist were collected from two force sensors positioned on both sides of the patient's hips. Measures to characterize the therapeutic balance assistance were the amount of force, duration, impulse and the anatomical plane in which the assistance took place. Based on the acceleration data of the sacrum, an algorithm was developed to predict therapeutic balance assistance. To validate the developed algorithm, the predicted events of balance assistance by the algorithm were compared with the actual provided therapeutic assistance. The algorithm was able to predict the actual therapeutic assistance with a Positive Predictive Value of 87% and a True Positive Rate of 81%. Assistance mainly took place over the medio-lateral axis and corrective forces of about 2% of the patient's body weight (15.9 N (11), median (IQR)) were provided by therapists in this plane. Median duration of balance assistance was 1.1 s (0.6) (median (IQR)) and median impulse was 9.4Ns (8.2) (median (IQR)). Although therapists were specifically instructed to aim for the force sensors on the iliac crest, a different contact location was reported in 22% of the corrections. This paper presents insights into the behavior of therapists regarding their manual physical assistance during gait training. A quantitative dataset was presented, representing therapeutic balance-assisting force characteristics. Furthermore, an algorithm was developed that predicts events at which therapeutic balance assistance was provided. Prediction scores remain high when different therapists and patients were analyzed with the same algorithm settings. Both the quantitative dataset and the developed algorithm can serve as technical input in the development of (robot-controlled) balance supportive devices.

Novel near infrared sensors for hybrid BCI applications

NASA Astrophysics Data System (ADS)

Almajidy, Rand K.; Le, Khang S.; Hofmann, Ulrich G.

2015-07-01

This study's goal is to develop a low cost, portable, accurate and comfortable NIRS module that can be used simultaneously with EEG in a dual modality system for brain computer interface (BCI). The sensing modules consist of electroencephalography (EEG) electrodes (at the positions Fp1, Fpz and Fp2 in the international 10-20 system) with eight custom made functional near infrared spectroscopy (fNIRS) channels, positioned on the prefrontal cortex area with two extra channels to measure and eliminate extra-cranial oxygenation. The NIRS sensors were designed to guarantee good sensor-skin contact, without causing subject discomfort, using springs to press them to the skin instead of pressing them by cap fixture. Two open source software packages were modified to carry out dual modality hybrid BCI experiments. The experimental paradigm consisted of a mental task (arithmetic task or text reading) and a resting period. Both oxygenated hemoglobin concentration changes (HbO), and EEG signals showed an increase during the mental task, but the onset, period and amount of that increase depends on each modality's characteristics. The subject's degree of attention played an important role especially during online sessions. The sensors can be easily used to acquire brain signals from different cerebral cortex parts. The system serves as a simple technological test bed and will be used for stroke patient rehabilitation purposes.

Detection of Lightning-produced NOx by Air Quality Monitoring Stations in Israel

NASA Astrophysics Data System (ADS)

Yair, Y.; Shalev, S.; Saaroni, H.; Ziv, B.

2011-12-01

Lightning is the largest natural source for the production of nitrogen oxides (LtNOx) in the troposphere. Since NOx are greenhouse gases, it is important to know the global production rate of LtNOx for climate studies (present estimates range from 2 to 8 Tg per year) and to model its vertical distribution (Ott et al., 2010). One of the key factors for such an estimate is the yield of a single lightning flash, namely the number of molecules produced for each Joule of energy deposited along the lightning channel. We used lightning stroke data from the Israel Lightning Location System (ILLS) together with NOx data obtained from the national network of air quality monitoring stations operated by the Israeli Ministry of Environmental Protection. Looking for the fingerprints of LtNOx in the general ambient concentrations, usually most affected by pollution from urban sources, we looked only for CG strokes occurring within a radius of 3 km from the location of an air-quality monitoring station. This lowered the number of relevant cases from 605,413 strokes detected in the 2004/5 through 2009/10 seasons to 1,897 strokes. We applied a threshold of > 60kA reducing the number of events to 35. The results showed that there was no consistent rising trend in the NOx concentrations in the hour following the lightning (the lifetime near the ground is expected to be a few hours; Zhang et al., 2003). However, when considering only those events when the prevailing wind was in the direction from the stroke location toward the sensor (7 cases), a clear increase of few ppb following the stroke was observed in 5 cases [see Fig.]. This increase is well correlated with the wind speed, suggesting an effective transport from the stroke location to the sensor. Weaker winds allow dilution and result in smaller observed increases of LtNOx. Separate analysis of additional 17 cases in which the strokes were located < 500 m from the monitoring station (with any peak current above 7 kA) showed no consistent trend. When excluding the 7 events that occurred during rush hour traffic, we found 6 (of 10) cases with an average increase in NOx concentrations of 16 ppb in the hour following the lightning. These results suggest a contribution of CG lightning strokes to the ground level concentrations of NOx. L. E. Ott, K. E. Pickering, G. L. Stenchikov, D. J. Allen, A. J. DeCaria, B. Ridley, R.F. Lin, S. Lang, and W.K. Tao (2010), Production of lightning NOx and its vertical distribution calculated from three dimensional cloud scale chemical transport model simulations, J. Geophys. Res., 115, D04301, doi:10.1029/2009JD011880

Electrical bioimpedance enabling prompt intervention in traumatic brain injury

NASA Astrophysics Data System (ADS)

Seoane, Fernando; Atefi, S. Reza

2017-05-01

Electrical Bioimpedance (EBI) is a well spread technology used in clinical practice across the world. Advancements in Textile material technology with conductive textile fabrics and textile-electronics integration have allowed exploring potential applications for Wearable Measurement Sensors and Systems exploiting. The sensing principle of electrical bioimpedance is based on the intrinsic passive dielectric properties of biological tissue. Using a pair of electrodes, tissue is electrically stimulated and the electrical response can be sensed with another pair of surface electrodes. EBI spectroscopy application for cerebral monitoring of neurological conditions such as stroke and perinatal asphyxia in newborns have been justified using animal studies and computational simulations. Such studies have shown proof of principle that neurological pathologies indeed modify the dielectric composition of the brain that is detectable via EBI. Similar to stroke, Traumatic Brain Injury (TBI) also affects the dielectric properties of brain tissue that can be detected via EBI measurements. Considering the portable and noninvasive characteristics of EBI it is potentially useful for prehospital triage of TBI patients where. In the battlefield blast induced Traumatic Brain Injuries are very common. Brain damage must be assessed promptly to have a chance to prevent severe damage or eventually death. The relatively low-complexity of the sensing hardware required for EBI sensing and the already proven compatibility with textile electrodes suggest the EBI technology is indeed a candidate for developing a handheld device equipped with a sensorized textile cap to produce an examination in minutes for enabling medically-guided prompt intervention.

Deep-brain stimulator and control of Parkinson's disease

NASA Astrophysics Data System (ADS)

Varadan, Vijay K.; Harbaugh, Robert; Abraham, Jose K.

2004-07-01

The design of a novel feedback sensor system with wireless implantable polymer MEMS sensors for detecting and wirelessly transmitting physiological data that can be used for the diagnosis and treatment of various neurological disorders, such as Parkinson's disease, epilepsy, head injury, stroke, hydrocephalus, changes in pressure, patient movements, and tremors is presented in this paper. The sensor system includes MEMS gyroscopes, accelerometers, and pressure sensors. This feedback sensor system focuses on the development and integration of implantable systems with various wireless sensors for medical applications, particularly for the Parkinson's disease. It is easy to integrate and modify the sensor network feed back system for other neurological disorders mentioned above. The monitoring and control of tremor in Parkinson's disease can be simulated on a skeleton via wireless telemetry system communicating with electroactive polymer actuator, and microsensors attached to the skeleton hand and legs. Upon sensing any abnormal motor activity which represent the characteristic rhythmic motion of a typical Parkinson's (PD) patient, these sensors will generate necessary control pulses which will be transmitted to a hat sensor system on the skeleton head. Tiny inductively coupled antennas attached to the hat sensor system can receive these control pulses, demodulate and deliver it to actuate the parts of the skeleton to control the abnormal motor activity. This feedback sensor system can further monitor and control depending on the amplitude of the abnormal motor activity. This microsystem offers cost effective means of monitoring and controlling of neurological disorders in real PD patients. Also, this network system offers a remote monitoring of the patients conditions without visiting doctors office or hospitals. The data can be monitored using PDA and can be accessed using internet (or cell phone). Cellular phone technology will allow a health care worker to be automatically notified if monitoring indicates an emergency situation. The main advantage of such system is that it can effectively monitor large number of patients at the same time, which helps to compensate the present shortage of health care workers.

XBP1 (X-Box-Binding Protein-1)-Dependent O-GlcNAcylation Is Neuroprotective in Ischemic Stroke in Young Mice and Its Impairment in Aged Mice Is Rescued by Thiamet-G.

PubMed

Jiang, Meng; Yu, Shu; Yu, Zhui; Sheng, Huaxin; Li, Ying; Liu, Shuai; Warner, David S; Paschen, Wulf; Yang, Wei

2017-06-01

Impaired protein homeostasis induced by endoplasmic reticulum dysfunction is a key feature of a variety of age-related brain diseases including stroke. To restore endoplasmic reticulum function impaired by stress, the unfolded protein response is activated. A key unfolded protein response prosurvival pathway is controlled by the endoplasmic reticulum stress sensor (inositol-requiring enzyme-1), XBP1 (downstream X-box-binding protein-1), and O-GlcNAc (O-linked β-N-acetylglucosamine) modification of proteins (O-GlcNAcylation). Stroke impairs endoplasmic reticulum function, which activates unfolded protein response. The rationale of this study was to explore the potentials of the IRE1/XBP1/O-GlcNAc axis as a target for neuroprotection in ischemic stroke. Mice with Xbp1 loss and gain of function in neurons were generated. Stroke was induced by transient or permanent occlusion of the middle cerebral artery in young and aged mice. Thiamet-G was used to increase O-GlcNAcylation. Deletion of Xbp1 worsened outcome after transient and permanent middle cerebral artery occlusion. After stroke, O-GlcNAcylation was activated in neurons of the stroke penumbra in young mice, which was largely Xbp1 dependent. This activation of O-GlcNAcylation was impaired in aged mice. Pharmacological increase of O-GlcNAcylation before or after stroke improved outcome in both young and aged mice. Our study indicates a critical role for the IRE1/XBP1 unfolded protein response branch in stroke outcome. O-GlcNAcylation is a prosurvival pathway that is activated in the stroke penumbra in young mice but impaired in aged mice. Boosting prosurvival pathways to counterbalance the age-related decline in the brain's self-healing capacity could be a promising strategy to improve ischemic stroke outcome in aged brains. © 2017 American Heart Association, Inc.

A Personalized Self-Management Rehabilitation System with an Intelligent Shoe for Stroke Survivors: A Realist Evaluation

PubMed Central

2016-01-01

Background In the United Kingdom, stroke is the most significant cause of adult disability. Stroke survivors are frequently left with physical and psychological changes that can profoundly affect their functional ability, independence, and social participation. Research suggests that long-term, intense, task- and context-specific rehabilitation that is goal-oriented and environmentally enriched improves function, independence, and quality of life after a stroke. It is recommended that rehabilitation should continue until maximum recovery has been achieved. However, the increasing demand on services and financial constraints means that needs cannot be met through traditional face-to-face delivery of rehabilitation. Using a participatory design methodology, we developed an information communication technology–enhanced Personalized Self-Managed rehabilitation System (PSMrS) for stroke survivors with integrated insole sensor technology within an “intelligent shoe.”. The intervention model was based around a rehabilitation paradigm underpinned by theories of motor relearning and neuroplastic adaptation, motivational feedback, self-efficacy, and knowledge transfer. Objective To understand the conditions under which this technology-based rehabilitation solution would most likely have an impact on the motor behavior of the user, what would work for whom, in what context, and how. We were interested in what aspects of the system would work best to facilitate the motor behavior change associated with self-managed rehabilitation and which user characteristics and circumstances of use could promote improved functional outcomes. Methods We used a Realist Evaluation (RE) framework to evaluate the final prototype PSMrS with the assumption that the intervention consists of a series of configurations that include the Context of use, the underlying Mechanisms of change and the potential Outcomes or impacts (CMOs). We developed the CMOs from literature reviews and engagement with clinicians, users, and caregivers during a series of focus groups and home visits. These CMOs were then tested in five in-depth case studies with stroke survivors and their caregivers. Results While two new propositions emerged, the second importantly related to the self-management aspects of the system. The study revealed that the system should also encourage independent use and the setting of personalized goals or activities. Conclusions Information communication technology that purports to support the self-management of stroke rehabilitation should give significant consideration to the need for motivational feedback that provides quantitative, reliable, accurate, context-specific, and culturally sensitive information about the achievement of personalized goal-based activities. PMID:28582250

A Personalized Self-Management Rehabilitation System with an Intelligent Shoe for Stroke Survivors: A Realist Evaluation.

PubMed

Mawson, Susan; Nasr, Nasrin; Parker, Jack; Davies, Richard; Zheng, Huiru; Mountain, Gail

2016-01-07

In the United Kingdom, stroke is the most significant cause of adult disability. Stroke survivors are frequently left with physical and psychological changes that can profoundly affect their functional ability, independence, and social participation. Research suggests that long-term, intense, task- and context-specific rehabilitation that is goal-oriented and environmentally enriched improves function, independence, and quality of life after a stroke. It is recommended that rehabilitation should continue until maximum recovery has been achieved. However, the increasing demand on services and financial constraints means that needs cannot be met through traditional face-to-face delivery of rehabilitation. Using a participatory design methodology, we developed an information communication technology-enhanced Personalized Self-Managed rehabilitation System (PSMrS) for stroke survivors with integrated insole sensor technology within an "intelligent shoe.". The intervention model was based around a rehabilitation paradigm underpinned by theories of motor relearning and neuroplastic adaptation, motivational feedback, self-efficacy, and knowledge transfer. To understand the conditions under which this technology-based rehabilitation solution would most likely have an impact on the motor behavior of the user, what would work for whom, in what context, and how. We were interested in what aspects of the system would work best to facilitate the motor behavior change associated with self-managed rehabilitation and which user characteristics and circumstances of use could promote improved functional outcomes. We used a Realist Evaluation (RE) framework to evaluate the final prototype PSMrS with the assumption that the intervention consists of a series of configurations that include the Context of use, the underlying Mechanisms of change and the potential Outcomes or impacts (CMOs). We developed the CMOs from literature reviews and engagement with clinicians, users, and caregivers during a series of focus groups and home visits. These CMOs were then tested in five in-depth case studies with stroke survivors and their caregivers. While two new propositions emerged, the second importantly related to the self-management aspects of the system. The study revealed that the system should also encourage independent use and the setting of personalized goals or activities. Information communication technology that purports to support the self-management of stroke rehabilitation should give significant consideration to the need for motivational feedback that provides quantitative, reliable, accurate, context-specific, and culturally sensitive information about the achievement of personalized goal-based activities. ©Susan Mawson, Nasrin Nasr, Jack Parker, Richard Davies, Huiri Zheng, Gail Mountain. Originally published in JMIR Rehabilitation and Assistive Technology (http://rehab.jmir.org), 07.01.2016.

Static telescope aberration measurement using lucky imaging techniques

NASA Astrophysics Data System (ADS)

López-Marrero, Marcos; Rodríguez-Ramos, Luis Fernando; Marichal-Hernández, José Gil; Rodríguez-Ramos, José Manuel

2012-07-01

A procedure has been developed to compute static aberrations once the telescope PSF has been measured with the lucky imaging technique, using a nearby star close to the object of interest as the point source to probe the optical system. This PSF is iteratively turned into a phase map at the pupil using the Gerchberg-Saxton algorithm and then converted to the appropriate actuation information for a deformable mirror having low actuator number but large stroke capability. The main advantage of this procedure is related with the capability of correcting static aberration at the specific pointing direction and without the need of a wavefront sensor.

Imaging cerebral haemorrhage with magnetic induction tomography: numerical modelling.

PubMed

Zolgharni, M; Ledger, P D; Armitage, D W; Holder, D S; Griffiths, H

2009-06-01

Magnetic induction tomography (MIT) is a new electromagnetic imaging modality which has the potential to image changes in the electrical conductivity of the brain due to different pathologies. In this study the feasibility of detecting haemorrhagic cerebral stroke with a 16-channel MIT system operating at 10 MHz was investigated. The finite-element method combined with a realistic, multi-layer, head model comprising 12 different tissues, was used for the simulations in the commercial FE package, Comsol Multiphysics. The eddy-current problem was solved and the MIT signals computed for strokes of different volumes occurring at different locations in the brain. The results revealed that a large, peripheral stroke (volume 49 cm(3)) produced phase changes that would be detectable with our currently achievable instrumentation phase noise level (17 m degrees ) in 70 (27%) of the 256 exciter/sensor channel combinations. However, reconstructed images showed that a lower noise level than this, of 1 m degrees , was necessary to obtain good visualization of the strokes. The simulated MIT measurements were compared with those from an independent transmission-line-matrix model in order to give confidence in the results.

Development of a chronic disease management program for stroke survivors using intervention mapping: The Stroke Coach

PubMed Central

Sakakibara, Brodie M.; Lear, Scott A.; Barr, Susan I.; Benavente, Oscar; Goldsmith, Charlie H.; Silverberg, Noah D.; Yao, Jennifer; Eng, Janice J.

2018-01-01

Objective To describe the systematic development of the Stroke Coach, a theory- and evidence-based intervention to improve control of lifestyle behaviour risk factors in stroke patients. Design Intervention development. Setting Community. Participants Individuals who have had a stroke. Intervention We used Intervention Mapping to guide the development of the Stroke Coach. Intervention Mapping is a systematic process used for intervention development and comprised of steps that progress from the integration of theory and evidence to the organization of realistic strategies to facilitate the development of a practical intervention supported by empirical evidence. Social Cognitive Theory was the underlying premise for behaviour change, while Control Theory methods were directed towards sustaining the changes to ensure long-term health benefits. Practical evidence-based strategies were linked to behavioural determinants to improve stroke risk factor control. Main outcome measures Not applicable. Results The Stroke Coach is a patient-centred, community-based, telehealth intervention to promote healthy lifestyles after stroke. Over six months, participants receive seven 30 to 60 minute telephone sessions with a lifestyle coach who provides education, facilitates motivation for lifestyle modification, and empowers participants to self-management their stroke risk factors. Participants also receive a self-management manual and a self-monitoring kit. Conclusion Through the use of Intervention Mapping we developed a theoretically sound and evidence-grounded intervention to improve risk factor control in stroke patients. If empirical evaluation of the Stroke Coach produces positive results, the next step will be to develop an implementation intervention to ensure successful uptake and delivery of the program in community and outpatient settings. PMID:28219685

Autonomous locomotion of capsule endoscope in gastrointestinal tract.

PubMed

Yang, Sungwook; Park, Kitae; Kim, Jinseok; Kim, Tae Song; Cho, Il-Joo; Yoon, Eui-Sung

2011-01-01

Autonomous locomotion in gastrointestinal (GI) tracts is achieved with a paddling-based capsule endoscope. For this, a miniaturized encoder module was developed utilizing a MEMS fabrication technology to monitor the position of paddles. The integrated encoder module yielded the high resolution of 0.0025 mm in the linear motion of the paddles. In addition, a PID control method was implemented on a DSP to control the stroke of the paddles accurately. As a result, the average accuracy and the standard deviation were measured to be 0.037 mm and 0.025 mm by a laser position sensor for the repetitive measurements. The locomotive performance was evaluated via ex-vivo tests according to various strokes in paddling. In an in-vivo experiment with a living pig, the locomotion speed was improved by 58% compared with the previous control method relying on a given timer value for reciprocation of the paddles. Finally, the integrated encoder module and the control system allow consistent paddling during locomotion even under loads in GI tract. It provides the autonomous locomotion without intervention in monitoring and controlling the capsule endoscope.

Tropical Cyclone Lightning Distribution and Its Relationship to Convection and Intensity Change

NASA Technical Reports Server (NTRS)

Rodgers, Edward; Wienman, James; Pierce, Harold; Olson, William

2000-01-01

The long distance National Lightning Detection Network (NLDN) was used to monitor the distribution of lightning strokes in various 1998 and 1999 western North Atlantic tropical cyclones. These ground-based lightning observations together with the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave/Imager (SSM/I) and the Tropical Rain Mapping Mission (TRMM) Microwave Instrument (TMI) derived convective rain rates were used to monitor the propagation of electrically charged convective rain bands aid to qualitatively estimate intensification. An example of the lightning analyses was performed on hurricane George between 25-28 September, 1998 when the system left Key West and moved towards the Louisiana coast. During this period of time, George's maximum winds increased from 38 to 45 meters per second on 25 September and then remained steady state until it made landfall. Time-radius displays of the lightning strokes indicated that the greatest number of lightning strokes occurred within the outer core region (greater than 165 km) with little or no lightning strokes at radii less than 165 km. The trend in these lightning strokes decreased as George move into the Gulf of Mexico and showed no inward propagation. The lack inward propagating lightning strokes with time indicated that there was no evidence that an eye wall replacement was occurring that could alter George's intensity. Since George was steady state at this time, this result is not surprising. Time-azimuth displays of lightning strokes in an annulus whose outer and inner radii were respectively, 222 and 333 km from George's center were also constructed. A result from this analysis indicated that the maximum number of strokes occurred in the forward and rear right quadrant when George was over the Gulf of Mexico. This result is, consistent with the aircraft and satellite observations of maximum rainfall.

Effect of surface conductivity on the peak magnetic field radiated by first return strokes in cloud-to-ground lightning

NASA Technical Reports Server (NTRS)

Tyahla, Lori J.; Lopez, Raul E.

1994-01-01

The effect of surface conductivity on the peak magnetic field radiated by the first return stroke in cloud-to-ground lightning was investigated by comparing the peak magnetic fields from return strokes that struck water with those that struck land. The data were obtained from a network of three gated, wideband magnetic direction finders (DFs) at the NASA Kennedy Space Center during the summer of 1985. Two geographical areas that were equidistant from two of the direction finders were compared where the flash distances ranged from approximately 40 to 60 km. An unbiased data set was obtained by correcting site errors, equalizing differences in sensor gain, eliminating directional biases in DF triggering, and keeping differences in signal attenuation over the two surfaces to a minimum. When a statistical analysis was performed on the frequency distributions of the signal amplitudes, there was no statistically significant difference in the peak amplitudes of first return strokes over land (lambda = 8.2 x 10(exp -3) mho/m) and over water (lambda = 4 mho/m). Therefore we infer that the conductivity of the underlying surface does not significantly affect the magnitude of the peak magnetic field, and hence the peak current, in the first return stroke of a cloud-to-ground lightning flash.

UPDATE ON THE GLOBAL BURDEN OF ISCHAEMIC AND HAEMORRHAGIC STROKE IN 1990–2013: THE GBD 2013 STUDY

PubMed Central

Feigin, Valery L.; Krishnamurthi, Rita; Parmar, Priya; Norrving, Bo; Mensah, George A.; Bennett, Derrick A.; Barker-Collo, Suzanne; Moran, Andrew; Sacco, Ralph L.; Truelsen, Thomas; Davis, Stephen; Pandian, Jeyaraj Durai; Naghavi, Mohsen; Forouzanfar, Mohammad H.; Nguyen, Grant; Johnson, Catherine O.; Vos, Theo; Meretoja, Atte; Murray, Christopher; Roth, Gregory A.; Thrift, Amanda; Banerjee, Amitava; Kengne, Andre Pascal; Misganaw, Awoke; Kissela, Brett M.; Wolfe, Charles; Yu, Chuanhua; Anderson, Craig; Kim, Daniel; Rojas-Rueda, David; Tanne, David; Tirschwell, David Lawrence; Nand, Devina; Kazi, Dhruv S.; Pourmalek, Farshad; Catalá-López, Ferrán; Abd-Allah, Foad; Gankpé, Fortuné; deVeber, Gabrielle; Donnan, Geoffrey; Hankey, Graeme J.; Christensen, Hanne K.; Campos-Nonato, Ismael; Shiue, Ivy; Fernandes, Jefferson G.; Jonas, Jost B.; Sheth, Kevin; Kim, Yunjin; Dokova, Klara; Stroumpoulis, Konstantinos; Sposato, Luciano A.; Bahit, Maria Cecilia; Geleijnse, Johanna M.; Mackay, Mark T.; Mehndiratta, Man Mohan; Endres, Matthias; Giroud, Maurice; Brainin, Michael; Kravchenko, Michael; Piradov, Michael; Soljak, Michael; Liu, Ming; Connor, Myles; Venketasubramanian, Narayanaswamy; Bornstein, Natan; Shamalov, Nikolay; Roy, Nobhojit; Cabral, Norberto; Beauchamp, Norman J.; Lavados, Pablo M.; Jeemon, Panniyammakal; Lotufo, Paulo A.; Chowdhury, Rajiv; Sahathevan, Ramesh; Hamadeh, Randah R.; Malekzadeh, Reza; Gillium, Richard; Westerman, Ronny; Akinyemi, Rufus Olusola; Salman, Rustam Al-Shahi; Dharmaratne, Samath D.; Basu, Sanjay; Abera, Semaw Ferede; Kosen, Soewarta; Sampson, Uchechukwu K. A.; Caso, Valeria; Vlassov, Vasiliy; Melaku, Yohannes Adama; Kokubo, Yoshiohiro; Shinohara, Yukito; Varakin, Yuri; Wang, Wenzhi

2015-01-01

Background Global stroke epidemiology is changing rapidly. Although age-standardised rates of stroke mortality have decreased worldwide in the past two decades, the absolute numbers of people who have a stroke every year, live with the consequences of stroke, and die from their stroke are increasing. Regular updates on the current level of stroke burden are important for advancing our knowledge on stroke epidemiology and facilitate organization and planning of evidence-based stroke care. Objectives To estimate incidence, prevalence, mortality, disability-adjusted life-years (DALYs) and years lived with disability (YLDs), and their trends for ischaemic stroke (IS) and haemorrhagic stroke (HS) for 188 countries from 1990–2013. Methodology Stroke incidence, prevalence, mortality, DALYs and YLDs were estimated using all available data on mortality and stroke incidence, prevalence and excess mortality. Statistical models and country-level covariate data were employed and all rates were age-standardised to a global population. All estimated were produced with 95% uncertainty intervals (UI). Results In 2013, there were globally almost 25.7 million stroke survivors (71% with IS), 6.5 million deaths from stroke (51% died from IS), 113 million DALYs due to stroke (58% due to IS), and 10.3 million new strokes (67% IS). Over the 1990–2013 period, there was a significant increase in the absolute number of DALYs due to IS, and of deaths from IS and HS, survivors and incident events for both IS and HS. The preponderance of the burden of stroke continued to reside in developing countries, comprising 75.2% of deaths from stroke and 81.0% of stroke-related DALYs. Globally, the proportional contribution of stroke-related DALYs and deaths due to stroke compared to all diseases increased from 1990 (3.54% [95% UI 3.11–4.00%] and 9.66% [95% UI 8.47–10.70%]) to 2013 (4.62% [95% UI 4.01–5.30%] and 11.75% [95% UI 10.45–13.31%], respectively), but there was a diverging trend in developed and developing countries with a significant increase in DALYs and deaths in developing countries, and no measurable change in the proportional contribution of DALYs and deaths from stroke in developed countries. Conclusion Global stroke burden continues to increase globally. More efficient stroke prevention and management strategies are urgently needed to halt and eventually reverse the stroke pandemic, while universal access to organized stroke services should be a priority. PMID:26505981

Update on the Global Burden of Ischemic and Hemorrhagic Stroke in 1990-2013: The GBD 2013 Study.

PubMed

Feigin, Valery L; Krishnamurthi, Rita V; Parmar, Priya; Norrving, Bo; Mensah, George A; Bennett, Derrick A; Barker-Collo, Suzanne; Moran, Andrew E; Sacco, Ralph L; Truelsen, Thomas; Davis, Stephen; Pandian, Jeyaraj Durai; Naghavi, Mohsen; Forouzanfar, Mohammad H; Nguyen, Grant; Johnson, Catherine O; Vos, Theo; Meretoja, Atte; Murray, Christopher J L; Roth, Gregory A

2015-01-01

Global stroke epidemiology is changing rapidly. Although age-standardized rates of stroke mortality have decreased worldwide in the past 2 decades, the absolute numbers of people who have a stroke every year, and live with the consequences of stroke or die from their stroke, are increasing. Regular updates on the current level of stroke burden are important for advancing our knowledge on stroke epidemiology and facilitate organization and planning of evidence-based stroke care. This study aims to estimate incidence, prevalence, mortality, disability-adjusted life years (DALYs) and years lived with disability (YLDs) and their trends for ischemic stroke (IS) and hemorrhagic stroke (HS) for 188 countries from 1990 to 2013. Stroke incidence, prevalence, mortality, DALYs and YLDs were estimated using all available data on mortality and stroke incidence, prevalence and excess mortality. Statistical models and country-level covariate data were employed, and all rates were age-standardized to a global population. All estimates were produced with 95% uncertainty intervals (UIs). In 2013, there were globally almost 25.7 million stroke survivors (71% with IS), 6.5 million deaths from stroke (51% died from IS), 113 million DALYs due to stroke (58% due to IS) and 10.3 million new strokes (67% IS). Over the 1990-2013 period, there was a significant increase in the absolute number of DALYs due to IS, and of deaths from IS and HS, survivors and incident events for both IS and HS. The preponderance of the burden of stroke continued to reside in developing countries, comprising 75.2% of deaths from stroke and 81.0% of stroke-related DALYs. Globally, the proportional contribution of stroke-related DALYs and deaths due to stroke compared to all diseases increased from 1990 (3.54% (95% UI 3.11-4.00) and 9.66% (95% UI 8.47-10.70), respectively) to 2013 (4.62% (95% UI 4.01-5.30) and 11.75% (95% UI 10.45-13.31), respectively), but there was a diverging trend in developed and developing countries with a significant increase in DALYs and deaths in developing countries, and no measurable change in the proportional contribution of DALYs and deaths from stroke in developed countries. Global stroke burden continues to increase globally. More efficient stroke prevention and management strategies are urgently needed to halt and eventually reverse the stroke pandemic, while universal access to organized stroke services should be a priority. © 2015 S. Karger AG, Basel.

Development of a Chronic Disease Management Program for Stroke Survivors Using Intervention Mapping: The Stroke Coach.

PubMed

Sakakibara, Brodie M; Lear, Scott A; Barr, Susan I; Benavente, Oscar; Goldsmith, Charlie H; Silverberg, Noah D; Yao, Jennifer; Eng, Janice J

2017-06-01

To describe the systematic development of the Stroke Coach, a theory- and evidence-based intervention to improve control of lifestyle behavior risk factors in patients with stroke. Intervention development. Community. Individuals who have had a stroke. We used intervention mapping to guide the development of the Stroke Coach. Intervention mapping is a systematic process used for intervention development and composed of steps that progress from the integration of theory and evidence to the organization of realistic strategies to facilitate the development of a practical intervention supported by empirical evidence. Social cognitive theory was the underlying premise for behavior change, whereas control theory methods were directed toward sustaining the changes to ensure long-term health benefits. Practical evidence-based strategies were linked to behavioral determinants to improve stroke risk factor control. Not applicable. The Stroke Coach is a patient-centered, community-based, telehealth intervention to promote healthy lifestyles after stroke. Over 6 months, participants receive seven 30- to 60-minute telephone sessions with a lifestyle coach who provides education, facilitates motivation for lifestyle modification, and empowers participants to self-management their stroke risk factors. Participants also receive a self-management manual and a self-monitoring kit. Through the use of intervention mapping, we developed a theoretically sound and evidence-grounded intervention to improve risk factor control in patients with stroke. If empirical evaluation of the Stroke Coach produces positive results, the next step will be to develop an implementation intervention to ensure successful uptake and delivery of the program in community and outpatient settings. Copyright © 2017 American Congress of Rehabilitation Medicine. All rights reserved.

Early seizures predict the development of epilepsy in children and adolescents with stroke.

PubMed

Breitweg, Ina; Stülpnagel, Celina von; Pieper, Tom; Lidzba, Karen; Holthausen, Hans; Staudt, Martin; Kluger, Gerhard

2017-05-01

To identify risk factors for the development of epilepsy after pediatric stroke. Retrospective analysis of hospital charts of 93 children and adolescents with post-neonatal non-traumatic stroke and a minimum follow-up of two years. Seizures during the first 48 h after onset of stroke symptoms were defined as "early seizures"; when two or more seizures occurred after this period, the patient was classified as "epileptic". Early seizures, young age at stroke and MRI evidence of cortical involvement were observed more frequently in the children who developed epilepsy. These factors were, however, significantly interrelated; a stepwise multiple regression analysis in 46/93 patients with complete datasets identified only the occurrence of early seizures as a significant risk factor: 15/19 (79%) children with early seizures developed epilepsy, as opposed to only 7/53 (13%) without early seizures. Children with stroke who show seizures during the first 48 h after onset of stroke symptoms have a high risk to develop post-stroke epilepsy, whereas in children without early seizures, post-stroke epilepsy is rare. Copyright © 2016. Published by Elsevier Ltd.

Real-time monitoring of ischemic and contralateral brain pO2 during stroke by variable length multisite resonators

PubMed Central

Hou, Huagang; Li, Hongbin; Dong, Ruhong; Khan, Nadeem; Swartz, Harold

2014-01-01

Purpose Electron paramagnetic resonance (EPR) oximetry using variable length multi-probe implantable resonator (IR), was used to investigate the temporal changes in the ischemic and contralateral brain pO2 during stroke in rats. Material and Methods The EPR signal to noise ratio (S/N) of the IR with four sensor loops at a depth of up to11 mm were compared with direct implantation of lithium phthalocyanine (LiPc, oximetry probe) deposits in vitro. These IRs were used to follow the temporal changes in pO2 at two sites in each hemisphere during ischemia induced by left middle cerebral artery occlusion (MCAO) in rats breathing 30% O2 or 100% O2. Results The S/N ratios of the IRs were significantly greater than the LiPc deposits. A similar pO2 at two sites in each hemisphere prior to the onset of ischemia was observed in rats breathing 30% O2. However, a significant decline in the pO2 of the left cortex and striatum occurred during ischemia but no change in the pO2 of the contralateral brain was observed. A significant increase in the pO2 of only the contralateral non-ischemic brain was observed in the rats breathing 100% O2. No significant difference in the infarct volume was evident between the animals breathing 30% O2 or 100% O2 during ischemia. Conclusions EPR oximetry with IRs can repeatedly assess temporal changes in the brain pO2 at four sites simultaneously during stroke. This oximetry approach can be used to test and develop interventions to rescue ischemic tissue by modulating cerebral pO2 during stroke. PMID:24629514

Sensor technology more than a support.

PubMed

Olsson, Anna; Persson, Ann-Christine; Bartfai, Aniko; Boman, Inga-Lill

2018-03-01

This interview study is a part of a project that evaluated sensor technology as a support in everyday activities for patients with memory impairment. To explore patients with memory impairment and their partners' experiences of using sensor technology in their homes. Five patients with memory impairment after stroke and three partners were interviewed. Individual semi-structured interviews were analyzed with qualitative content analysis. Installing sensor technology with individually prerecorded voice reminders as memory support in the home had a broad impact on patients' and their families' lives. These effects were both positive and negative. The sensor technology not only supported activities but also influenced the patients by changing behavior, providing a sense of security, independence and increased self-confidence. For the partners, the sensor technology eased daily life, but also gave increased responsibility for maintenance. Technical problems led to frustration and stress for the patients. The results indicate that sensor technology has potential to increase opportunities for persons with memory impairment to perform and participate in activities and to unburden their partners. The results may promote an understanding of how sensor technology can be used to support persons with memory impairment in their homes.

Development of an Algorithm for Stroke Prediction: A National Health Insurance Database Study in Korea.

PubMed

Min, Seung Nam; Park, Se Jin; Kim, Dong Joon; Subramaniyam, Murali; Lee, Kyung-Sun

2018-01-01

Stroke is the second leading cause of death worldwide and remains an important health burden both for the individuals and for the national healthcare systems. Potentially modifiable risk factors for stroke include hypertension, cardiac disease, diabetes, and dysregulation of glucose metabolism, atrial fibrillation, and lifestyle factors. We aimed to derive a model equation for developing a stroke pre-diagnosis algorithm with the potentially modifiable risk factors. We used logistic regression for model derivation, together with data from the database of the Korea National Health Insurance Service (NHIS). We reviewed the NHIS records of 500,000 enrollees. For the regression analysis, data regarding 367 stroke patients were selected. The control group consisted of 500 patients followed up for 2 consecutive years and with no history of stroke. We developed a logistic regression model based on information regarding several well-known modifiable risk factors. The developed model could correctly discriminate between normal subjects and stroke patients in 65% of cases. The model developed in the present study can be applied in the clinical setting to estimate the probability of stroke in a year and thus improve the stroke prevention strategies in high-risk patients. The approach used to develop the stroke prevention algorithm can be applied for developing similar models for the pre-diagnosis of other diseases. © 2018 S. Karger AG, Basel.

Enhancing the development and approval of acute stroke therapies: Stroke Therapy Academic Industry roundtable.

PubMed

Fisher, Marc; Albers, Gregory W; Donnan, Geoffrey A; Furlan, Anthony J; Grotta, James C; Kidwell, Chelsea S; Sacco, Ralph L; Wechsler, Lawrence R

2005-08-01

Previous Stroke Therapy Academic Industry Roundtable (STAIR) meetings focused on preclinical evidence of drug efficacy and enhancing acute stroke trial design and performance. A fourth (STAIR-IV) was held to discuss relevant issues related to acute stroke drug development and regulatory approval. The STAIR-IV meeting had 3 main focus areas. The first topic was novel approaches to statistical design of acute stroke trials and appropriate outcome measures. The second focus was the need for better cooperation among participants in stroke therapy development that may be addressed through a national consortium of stroke trial centers in the United States and elsewhere. Lastly, regulatory issues related to the approval of novel mono and multiple acute stroke therapies were discussed. The development of additional acute stroke therapies represents a large unmet need with many remaining challenges and also opportunities to incorporate novel approaches to clinical trial design that will lead to regulatory approval. The STAIR-IV meeting explored new concepts of trial methodology and data analysis, initiatives for implementing a US clinical trialist consortium, and pertinent regulatory issues to expedite approval of novel therapies.

The European Stroke Organisation Guidelines: a standard operating procedure.

PubMed

Ntaios, George; Bornstein, Natan M; Caso, Valeria; Christensen, Hanne; De Keyser, Jacques; Diener, Hans-Christoph; Diez-Tejedor, Exuperio; Ferro, Jose M; Ford, Gary A; Grau, Armin; Keller, Emanuella; Leys, Didier; Russell, David; Toni, Danilo; Turc, Guillaume; Van der Worp, Bart; Wahlgren, Nils; Steiner, Thorsten

2015-10-01

In 2008, the recently founded European Stroke Organisation published its guidelines for the management of ischemic stroke and transient ischemic attack. This highly cited document was translated in several languages and was updated in 2009. Since then, the European Stroke Organisation has published guidelines for the management of intracranial aneurysms and subarachnoidal hemorrhage, for the establishment of stroke units and stroke centers, and recently for the management of intracerebral hemorrhage. In recent years, the methodology for the development of guidelines has evolved significantly. To keep pace with this progress and driven by the strong determination of the European Stroke Organisation to further promote stroke management, education, and research, the European Stroke Organisation decided to delineate a detailed standard operating procedure for its guidelines. There are two important cornerstones in this standard operating procedure: The first is the implementation of the Grading of Recommendations Assessment, Development, and Evaluation methodology for the development of its Guideline Documents. The second one is the decision of the European Stroke Organisation to move from the classical model of a single Guideline Document about a major topic (e.g. management of ischemic stroke) to focused modules (i.e. subdivisions of a major topic). This will enable the European Stroke Organisation to react faster when new developments in a specific stroke field occur and update its recommendations on the related module rather swiftly; with the previous approach of a single large Guideline Document, its entire revision had to be completed before an updated publication, delaying the production of up-to-date guidelines. After discussion within the European Stroke Organisation Guidelines Committee and significant input from European Stroke Organisation members as well as methodologists and analysts, this document presents the official standard operating procedure for the development of the Guideline Documents of the European Stroke Organisation. © 2015 World Stroke Organization.

Self-management develops through doing of everyday activities-a longitudinal qualitative study of stroke survivors during two years post-stroke.

PubMed

Satink, Ton; Josephsson, Staffan; Zajec, Jana; Cup, Edith H C; de Swart, Bert J M; Nijhuis-van der Sanden, Maria W G

2016-11-15

A description of the complexity of the process of self-management and the way stroke survivors give meaning to their process of self-management post-stroke is lacking. This study explores how stroke survivors managed their lives, gave meaning to their self-management post-stroke and how this evolved over time. Data was generated through participant observations and interviews of 10 stroke survivors at their homes at 3, 6, 9, 15 and 21 months post-discharge. A constant comparative method was chosen to analyse the data. 'Situated doing' was central in stroke survivors' simultaneous development of self-management and their sense of being in charge of everyday life post-stroke. Doing everyday activities provided the stroke survivors with an arena to explore, experience, evaluate, develop and adapt self-management and being in charge of everyday activities and daily life. The influence of stroke survivors' partners on this development was sometimes experienced as empowering and at other times as constraining. Over time, the meaning of self-management and being in charge changed from the opinion that self-management was doing everything yourself towards self-managing and being in charge, if necessary, with the help of others. Moreover, the sense of self-management and being in charge differed among participants: it ranged from managing only at the level of everyday activities to full role management and experiencing a meaningful and valuable life post-stroke. The findings of this study indicate the doing of activities as an important arena in which to develop self-management and being in charge post-stroke. Stroke self-management programs could best be delivered in stroke survivors' own environment and focus on not only stroke survivors but also their relatives. Furthermore, the focus of such interventions should be on not only the level of activities but also the existential level of self-management post-stroke.

The role of tactile sensation in online and offline hierarchical control of multi-finger force synergy.

PubMed

Koh, Kyung; Kwon, Hyun Joon; Yoon, Bum Chul; Cho, Yongseok; Shin, Joon-Ho; Hahn, Jin-Oh; Miller, Ross H; Kim, Yoon Hyuk; Shim, Jae Kun

2015-09-01

The hand, one of the most versatile but mechanically redundant parts of the human body, must overcome imperfect motor commands and inherent noise in both the sensory and motor systems in order to produce desired motor actions. For example, it is nearly impossible to produce a perfectly consistent note during a single violin stroke or to produce the exact same note over multiple strokes, which we denote online and offline control, respectively. To overcome these challenges, the central nervous system synergistically integrates multiple sensory modalities and coordinates multiple motor effectors. Among these sensory modalities, tactile sensation plays an important role in manual motor tasks by providing hand-object contact information. The purpose of this study was to investigate the role of tactile feedback in individual finger actions and multi-finger interactions during constant force production tasks. We developed analytical techniques for the linear decomposition of the overall variance in the motor system in both online and offline control. We removed tactile feedback from the fingers and demonstrated that tactile sensors played a critical role in the online control of synergistic interactions between fingers. In contrast, the same sensors did not contribute to offline control. We also demonstrated that when tactile feedback was removed from the fingers, the combined motor output of individual fingers did not change while individual finger behaviors did. This finding supports the idea of hierarchical control where individual fingers at the lower level work together to stabilize the performance of combined motor output at the higher level.

Pulse transit time measured by photoplethysmography improves the accuracy of heart rate as a surrogate measure of cardiac output, stroke volume and oxygen uptake in response to graded exercise.

PubMed

Pollonini, L; Padhye, N S; Re, R; Torricelli, A; Simpson, R J; Dacso, C C

2015-05-01

Heart rate (HR) is a valuable and widespread measure for physical training programs, although its description of conditioning is limited to the cardiac response to exercise. More comprehensive measures of exercise adaptation include cardiac output (Q̇), stroke volume (SV) and oxygen uptake (V̇O2), but these physiological parameters can be measured only with cumbersome equipment installed in clinical settings. In this work, we explore the ability of pulse transit time (PTT) to represent a valuable pairing with HR for indirectly estimating Q̇, SV and V̇O2 non-invasively. PTT was measured as the time interval between the peak of the electrocardiographic (ECG) R-wave and the onset of the photoplethysmography (PPG) waveform at the periphery (i.e. fingertip) with a portable sensor. Fifteen healthy young subjects underwent a graded incremental cycling protocol after which HR and PTT were correlated with Q̇, SV and V̇O2 using linear mixed models. The addition of PTT significantly improved the modeling of Q̇, SV and V̇O2 at the individual level ([Formula: see text] for SV, 0.548 for Q̇, and 0.771 for V̇O2) compared to predictive models based solely on HR ([Formula: see text] for SV, 0.503 for Q̇, and 0.745 for V̇O2). While challenges in sensitivity and artifact rejection exist, combining PTT with HR holds potential for development of novel wearable sensors that provide exercise assessment largely superior to HR monitors.

Inertial Gait Phase Detection for control of a drop foot stimulator Inertial sensing for gait phase detection.

PubMed

Kotiadis, D; Hermens, H J; Veltink, P H

2010-05-01

An Inertial Gait Phase Detection system was developed to replace heel switches and footswitches currently being used for the triggering of drop foot stimulators. A series of four algorithms utilising accelerometers and gyroscopes individually and in combination were tested and initial results are shown. Sensors were positioned on the outside of the upper shank. Tests were performed on data gathered from a subject, sufferer of stroke, implanted with a drop foot stimulator and triggered with the current trigger, the heel switch. Data tested includes a variety of activities representing everyday life. Flat surface walking, rough terrain and carpet walking show 100% detection and the ability of the algorithms to ignore non-gait events such as weight shifts. Timing analysis is performed against the current triggering method, the heel switch. After evaluating the heel switch timing against a reference system, namely the Vicon 370 marker and force plates system. Initial results show a close correlation between the current trigger detection and the inertial sensor based triggering algorithms. Algorithms were tested for stairs up and stairs down. Best results are observed for algorithms using gyroscope data. Algorithms were designed using threshold techniques for lowest possible computational load and with least possible sensor components to minimize power requirements and to allow for potential future implantation of sensor system.

Identifying compensatory movement patterns in the upper extremity using a wearable sensor system.

PubMed

Ranganathan, Rajiv; Wang, Rui; Dong, Bo; Biswas, Subir

2017-11-30

Movement impairments such as those due to stroke often result in the nervous system adopting atypical movements to compensate for movement deficits. Monitoring these compensatory patterns is critical for improving functional outcomes during rehabilitation. The purpose of this study was to test the feasibility and validity of a wearable sensor system for detecting compensatory trunk kinematics during activities of daily living. Participants with no history of neurological impairments performed reaching and manipulation tasks with their upper extremity, and their movements were recorded by a wearable sensor system and validated using a motion capture system. Compensatory movements of the trunk were induced using a brace that limited range of motion at the elbow. Our results showed that the elbow brace elicited compensatory movements of the trunk during reaching tasks but not manipulation tasks, and that a wearable sensor system with two sensors could reliably classify compensatory movements (~90% accuracy). These results show the potential of the wearable system to assess and monitor compensatory movements outside of a lab setting.

Development of blood extraction system for health monitoring system

NASA Astrophysics Data System (ADS)

Tsuchiya, Kazuyoshi; Nakanishi, Naoyuki; Nakamachi, Eiji

2004-03-01

The purpose of this research is to develop the compact human blood sampling device applied for a health monitoring system(HMS), which is called "Mobile Hospital". The HMS consists of (1) a micro electrical pumping system for blood extraction, (2) a bio-sensor to detect and evaluate an amount of Glucose, Cholesterol and Urea in extracted blood, by using enzyme such as Glucoseoxidase (GOD), Cholesteroloxidase and Urease. The mechanical design elements of the device are bio-compatible microneedle, indentation unit using a shape memory alloy(SMA) actuator and pumping unit using a piezoelectric microactuator. The design concept is the biomimetic micromachine of female mosquito"s blood sampling mechanism. The performances of the main mechanical elements such as indentation force of the microneedle, actual stroke of the indentation unit using a SMA actuator and liquid sampling ability of the pumping unit using PZT piezoelectric microactuator were measured. The 3 mm stroke of the indentation load generated by SMA actuator was 0.8mN. The amount of imitation blood extracted by using bimorph PZT actuators was about 0.5 microliters for 10 sec. A 60-micrometer outer diameter and 25-micrometer inner diameter Titanium microneedle, which size is same as female mosquito"s labium, was produced by sputter deposition.

Development of smartphone application that aids stroke screening and identifying nearby acute stroke care hospitals.

PubMed

Nam, Hyo Suk; Heo, JoonNyung; Kim, Jinkwon; Kim, Young Dae; Song, Tae Jin; Park, Eunjeong; Heo, Ji Hoe

2014-01-01

The benefits of thrombolytic treatment are time-dependent. We developed a smartphone application that aids stroke patient self-screening and hospital selection, and may also decrease hospital arrival time. The application was developed for iPhone and Android smartphones. Map data for the application were adopted from the open map. For hospital registration, a web page (http://stroke119.org) was developed using PHP and MySQL. The Stroke 119 application includes a stroke screening tool and real-time information on nearby hospitals that provide thrombolytic treatment. It also provides information on stroke symptoms, thrombolytic treatment, and prescribed actions when stroke is suspected. The stroke screening tool was adopted from the Cincinnati Prehospital Stroke Scale and is displayed in a cartoon format. If the user taps a cartoon image that represents abnormal findings, a pop-up window shows that the user may be having a stroke, informs the user what to do, and directs the user to call emergency services. Information on nearby hospitals is provided in map and list views, incorporating proximity to the user's location using a Global Positioning System (a built-in function of smartphones). Users can search for a hospital according to specialty and treatment levels. We also developed a web page for hospitals to register in the system. Neurology training hospitals and hospitals that provide acute stroke care in Korea were invited to register. Seventy-seven hospitals had completed registration. This application may be useful for reducing hospital arrival times for thrombolytic candidates.

Investigation of an optical sensor for small tilt angle detection of a precision linear stage

NASA Astrophysics Data System (ADS)

Saito, Yusuke; Arai, Yoshikazu; Gao, Wei

2010-05-01

This paper presents evaluation results of the characteristics of the angle sensor based on the laser autocollimation method for small tilt angle detection of a precision linear stage. The sensor consists of a laser diode (LD) as the light source, and a quadrant photodiode (QPD) as the position-sensing detector. A small plane mirror is mounted on the moving table of the stage as a target mirror for the sensor. This optical system has advantages of high sensitivity, fast response speed and the ability for two-axis angle detection. On the other hand, the sensitivity of the sensor is determined by the size of the optical spot focused on the QPD, which is a function of the diameter of the laser beam projected onto the target mirror. Because the diameter is influenced by the divergence of the laser beam, this paper focuses on the relationship between the sensor sensitivity and the moving position of the target mirror (sensor working distance) over the moving stroke of the stage. The main error components that influence the sensor sensitivity are discussed and the optimal conditions of the optical system of the sensor are analyzed. The experimental result about evaluation of the effective working distance is also presented.

Two-stroke engine diagnostics and design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1992-01-01

This paper focuses on research and development efforts on two-stroke cycle engines for automotive applications. Partial contents include: Velocity Field Characteristics in Motored Two-Stroke Ported Engines; Flow Vector Measurements at the Scavenging Ports in a Fired Two-Stroke Engine; A Study on Exhaust Dynamic Effect of Two-Stroke Motorcycle Petrol Engine; Characterization of Ignition and Parametric Study of a Two-Stroke-Cycle Direct-Injected Gasoline Engine; LDV Measurements of Intake Port Flow in a Two-Stroke Engine with and without Combustion; Appraisal of Regenerative Blowers for Scavenging of Small 2T S.I. Powerplants; and Development Experience of a Poppet-Valved Two-Stroke Flagship Engine.

Seizure development after stroke.

PubMed

Misirli, H; Ozge, A; Somay, G; Erdoğan, N; Erkal, H; Erenoğlu, N Y

2006-12-01

Although there have been many studies on seizures following stroke, there is still much we do not know about them. In this study, we evaluated the characteristics of seizures in stroke patients. There were 2267 patients with a first-ever stroke, and after excluding 387 patients, 1880 were available for analysis. Of these 1880 patients, we evaluated 200 patients with seizures and 400 patients without seizures. We investigated the seizures according to age, gender, stroke type, the aetiology of ischaemic stroke and the localisation of the lesion. The seizures were classified as early onset and late onset and the seizure type as partial, generalised or secondarily generalised. Seizures occurred in 200 (10.6%) of 1880 strokes. The number of patients with seizures were 138 (10.6%) in ischaemic stroke group and 62 (10.7%) in haemorrhagic stroke group. Patients with ischaemic strokes had 41 embolic (29.7%) and 97 thrombotic (70.3%) origin, and these were not statistically significant in comparison with controls. Cortical involvement for the development of seizures was the most important risk factor (odds ratios = 4.25, p < 0.01). It was concluded that embolic strokes, being younger than 65 years old, and cortical localisation of stroke were important risks for developing seizures.

HAMS (Hypoxia, Monitoring, and Mitigation System) II Quarterly Progress Report (Technical and Financial)

DTIC Science & Technology

2015-04-10

Peripheral Interface SpO2 Arterial Oxygen Saturation Measured via Pulse - Oximeter SRS Software Requirements Specification SV Stroke Volume SVR Systemic...viewer ....................................................................................................... 9 Figure 3: Pulse OX custom module...analysis approaches will be gathered. Sensors which detect SpO2, pulse / pulse rate, ECG, and skin temperature will be researched and evaluated for

Motor Impairment Evaluation for Upper Limb in Stroke Patients on the Basis of a Microsensor

ERIC Educational Resources Information Center

Huang, Shuai; Luo, Chun; Ye, Shiwei; Liu, Fei; Xie, Bin; Wang, Caifeng; Yang, Li; Huang, Zhen; Wu, Jiankang

2012-01-01

There has been an urgent need for an effective and efficient upper limb rehabilitation method for poststroke patients. We present a Micro-Sensor-based Upper Limb rehabilitation System for poststroke patients. The wearable motion capture units are attached to upper limb segments embedded in the fabric of garments. The body segment orientation…

77 FR 37445 - Notice of Permit Modification Received Under the Antarctic Conservation Act of 1978 (Pub. L. 95-541)

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-21

... depth, swim speed, ambient temperature, and light levels, stomach temperature, heat flux and skin temperature. An additional stroke frequency sensor is glued to the base of the tail. These tests and... photogrammetric models and infrared analysis and ultrasound measurements of blubber depth, collect blood samples...

Society of Vascular and Interventional Neurology (SVIN) Stroke Interventional Laboratory Consensus (SILC) Criteria: A 7M Management Approach to Developing a Stroke Interventional Laboratory in the Era of Stroke Thrombectomy for Large Vessel Occlusions

PubMed Central

Shams, Tanzila; Zaidat, Osama; Yavagal, Dileep; Xavier, Andrew; Jovin, Tudor; Janardhan, Vallabh

2016-01-01

Brain attack care is rapidly evolving with cutting-edge stroke interventions similar to the growth of heart attack care with cardiac interventions in the last two decades. As the field of stroke intervention is growing exponentially globally, there is clearly an unmet need to standardize stroke interventional laboratories for safe, effective, and timely stroke care. Towards this goal, the Society of Vascular and Interventional Neurology (SVIN) Writing Committee has developed the Stroke Interventional Laboratory Consensus (SILC) criteria using a 7M management approach for the development and standardization of each stroke interventional laboratory within stroke centers. The SILC criteria include: (1) manpower: personnel including roles of medical and administrative directors, attending physicians, fellows, physician extenders, and all the key stakeholders in the stroke chain of survival; (2) machines: resources needed in terms of physical facilities, and angiography equipment; (3) materials: medical device inventory, medications, and angiography supplies; (4) methods: standardized protocols for stroke workflow optimization; (5) metrics (volume): existing credentialing criteria for facilities and stroke interventionalists; (6) metrics (quality): benchmarks for quality assurance; (7) metrics (safety): radiation and procedural safety practices. PMID:27610118

'Care for Stroke', a web-based, smartphone-enabled educational intervention for management of physical disabilities following stroke: feasibility in the Indian context.

PubMed

Sureshkumar, K; Murthy, G V S; Munuswamy, Suresh; Goenka, Shifalika; Kuper, Hannah

2015-07-01

Stroke rehabilitation is a process targeted towards restoration or maintenance of the physical, mental, intellectual and social abilities of an individual affected by stroke. Unlike high-income countries, the resources for stroke rehabilitation are very limited in many low-income and middle-income countries (LMICs). Provision of cost-effective, post-stroke multidisciplinary rehabilitation services for the stroke survivors therefore becomes crucial to address the unmet needs and growing magnitude of disability experienced by the stroke survivors in LMICs. In order to meet the growing need for post-stroke rehabilitation services in India, we developed a web-based Smartphone-enabled educational intervention for management of physical disabilities following a stroke. On the basis of the findings from the rehabilitation needs assessment study, guidance from the expert group and available evidence from systematic reviews, the framework of the intervention content was designed. Web-based application designing and development by Professional application developers were subsequently undertaken. The application is called 'Care for Stroke'. It is a web-based educational intervention for management of physical disabilities following a stroke. This intervention is developed for use by the Stroke survivors who have any kind of rehabilitation needs to independently participate in his/her family and social roles. 'Care for stroke' is an innovative intervention which could be tested not just for its feasibility and acceptability but also for its clinical and cost-effectiveness through rigorously designed, randomised clinical trials. It is very important to test this intervention in LMICs where the rehabilitation and information needs of the stroke survivors seem to be substantial and largely unmet.

Stop Stroke: development of an innovative intervention to improve risk factor management after stroke.

PubMed

Redfern, Judith; Rudd, Anthony D; Wolfe, Charles D A; McKevitt, Christopher

2008-08-01

Stroke survivors are at high risk of stroke recurrence yet current strategies to reduce recurrence risk are sub-optimal. The UK Medical Research Council (MRC) have proposed a framework for developing and evaluating complex interventions, such as community management of stroke secondary prevention. The Framework outlines a five-phased approach from theory through to implementation of effective interventions. This paper reports Phases I-III of the development of a novel intervention to improve risk factor management after stroke. The pre-clinical/theoretical phase entailed reviewing the literature and undertaking quantitative and qualitative studies to identify current practices and barriers to secondary prevention. In Phase I (modelling), findings were used to design an intervention with the potential to overcome barriers to effective stroke secondary prevention management. The feasibility of delivering the intervention and its acceptability were tested in the Phase II exploratory trial involving 25 stroke survivors and their general practitioners. This led to the development of the definitive risk factor management intervention. This comprises multiple components and involves using an on-going population stroke register to target patients, carers and health care professionals with tailored secondary prevention advice. Clinical, socio-demographic and service use data collected by the stroke register are transformed to provide an individualised secondary prevention package for patients, carers and health care professionals at three time points: within 10 weeks, 3 and 6 months post-stroke. The intervention is currently being evaluated in a randomised controlled trial. Further research is needed to test generalisability to other aspects of stroke management and for other chronic diseases. The MRC Framework for complex interventions provides a structured approach to guide the development of novel interventions in public health. Implications for practice in stroke secondary prevention will emerge when the results of our randomised controlled trial are published.

Rocking the boat: does perfect rowing crew synchronization reduce detrimental boat movements?

PubMed

Cuijpers, L S; Passos, P J M; Murgia, A; Hoogerheide, A; Lemmink, K A P M; de Poel, H J

2017-12-01

In crew rowing, crew members need to mutually synchronize their movements to achieve optimal crew performance. Intuitively, poor crew coordination is often deemed to involve additional boat movements such as surge velocity fluctuations, heave, pitch, and roll, which would imply lower efficiency (eg, due to increased hydrodynamic drag). The aim of this study was to investigate this alleged relation between crew coordination and boat movements at different stroke rates. Fifteen crews of two rowers rowed in a double scull (ie, a two-person boat) at 18, 22, 26, 30, and 34 strokes per minute. Oar angles (using potentiometers) and movements of the boat (using a three-axial accelerometer-gyroscope sensor) were measured (200 Hz). Results indicated that crew synchronization became more consistent with stroke rate, while surge, heave, and pitch fluctuations increased. Further, within each stroke rate condition, better crew synchronization was related to less roll of the boat, but increased fluctuations regarding surge, heave, and pitch. Together this demonstrates that while better crew synchronization relates to enhanced lateral stability of the boat, it inevitably involves more detrimental boat movements and hence involves lower biomechanical efficiency. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Assessing altered motor unit recruitment patterns in paretic muscles of stroke survivors using surface electromyography.

PubMed

Hu, Xiaogang; Suresh, Aneesha K; Rymer, William Z; Suresh, Nina L

2015-12-01

The advancement of surface electromyogram (sEMG) recording and signal processing techniques has allowed us to characterize the recruitment properties of a substantial population of motor units (MUs) non-invasively. Here we seek to determine whether MU recruitment properties are modified in paretic muscles of hemispheric stroke survivors. Using an advanced EMG sensor array, we recorded sEMG during isometric contractions of the first dorsal interosseous muscle over a range of contraction levels, from 20% to 60% of maximum, in both paretic and contralateral muscles of stroke survivors. Using MU decomposition techniques, MU action potential amplitudes and recruitment thresholds were derived for simultaneously activated MUs in each isometric contraction. Our results show a significant disruption of recruitment organization in paretic muscles, in that the size principle describing recruitment rank order was materially distorted. MUs were recruited over a very narrow force range with increasing force output, generating a strong clustering effect, when referenced to recruitment force magnitude. Such disturbances in MU properties also correlated well with the impairment of voluntary force generation. Our findings provide direct evidence regarding MU recruitment modifications in paretic muscles of stroke survivors, and suggest that these modifications may contribute to weakness for voluntary contractions.

From prevention to nursing home care: a comprehensive national audit of stroke care.

PubMed

Horgan, Frances; McGee, Hannah; Hickey, Anne; Whitford, David L; Murphy, Sean; Royston, Maeve; Cowman, Seamus; Shelley, Emer; Conroy, Ronan M; Wiley, Miriam; O'Neill, Desmond

2011-01-01

Many countries are developing national audits of stroke care. However, these typically focus on stroke care from acute event to hospital discharge rather than the full spectrum from prevention to long-term care. We report on a comprehensive national audit of stroke care in the community and hospitals in the Republic of Ireland. The findings provide insights into the wider needs of people with stroke and their families, a basis for developing stroke-appropriate health strategies, and a global model for the evaluation of stroke services. Six national surveys were completed: general practitioners (prevention and primary care), hospital organisational and clinical audit of 2,570 consecutive stroke admissions (acute and hospital care), allied health professionals and public health nurses (discharge to community care), nursing homes (needs of patients discharged to long-term care), and patient and carers (post-hospital phase of rehabilitation and ongoing care). The audit identified substantial deficits in a number of areas including primary prevention, emergency assessment/investigation and treatment in hospital, discharge planning, rehabilitation and ongoing secondary prevention, and communication with patients and families. There was a lack of coordination and communication between the acute and community services, with a dearth of therapy services in both home and nursing home settings. This multi-faceted national stroke audit facilitated multiple perspectives on the continuum of stroke prevention and care. An overall synthesis of surveys supports the development of a multidisciplinary perspective in planning the development of comprehensive stroke services at the national level, and may assist in regional and global development of stroke strategies. Copyright © 2011 S. Karger AG, Basel.

Improving stroke transitions: Development and implementation of a social work case management intervention.

PubMed

Hughes, Anne K; Woodward, Amanda T; Fritz, Michele C; Reeves, Mathew J

2018-02-01

Strokes impact over 800,000 people every year. Stroke care typically begins with inpatient care and then continues across an array of healthcare settings. These transitions are difficult for patients and caregivers, with psychosocial needs going unmet. Our team developed a case management intervention for acute stroke patients and their caregivers aimed at improving stroke transitions. The intervention focusses on four aspects of a successful care transition: support, preparedness, identifying and addressing unmet needs, and stroke education. This paper describes the development and implementation of this program, and is an example of the synergy created between neuroscience and clinical practice.

The efficacy of novel anatomical sites for the assessment of muscle oxygenation during central hypovolemia.

PubMed

Sprick, Justin D; Soller, Babs R; Rickards, Caroline A

2016-11-01

Muscle tissue oxygenation (SmO 2 ) can track central blood volume loss associated with hemorrhage. Traditional peripheral measurement sites (e.g., forearm) may not be practical due to excessive movement or injury (e.g., amputation). The aim of this study was to evaluate the efficacy of three novel anatomical sites for the assessment of SmO 2 under progressive central hypovolemia. 10 male volunteers were exposed to stepwise prone lower body negative pressure to decrease central blood volume, while SmO 2 was assessed at four sites-the traditional site of the flexor carpi ulnaris (ARM), and three novel sites not previously investigated during lower body negative pressure, the deltoid, latissimus dorsi, and trapezius. SmO 2 at the novel sites was compared to the ARM sensor and to stroke volume responses. A reduction in SmO 2 was detected by the ARM sensor at the first level of lower body negative pressure (-15 mmHg; P = 0.007), and at -30 (the deltoid), -45 (latissimus dorsi), and -60 mmHg lower body negative pressure (trapezius) at the novel sites (P ≤ 0.04). SmO 2 responses at all novel sites were correlated with responses at the ARM (R ≥ 0.89), and tracked the reduction in stroke volume (R ≥ 0.87); the latissimus dorsi site exhibited the strongest linear correlations (R ≥ 0.96). Of the novel sensor sites, the latissimus dorsi exhibited the strongest linear associations with SmO 2 at the ARM, and with reductions in central blood volume. These findings have important implications for detection of hemorrhage in austere environments (e.g., combat) when use of a peripheral sensor may not be ideal, and may facilitate incorporation of these sensors into uniforms. © 2016 by the Society for Experimental Biology and Medicine.

NASA Tech Briefs, April 2002. Volume 26, No. 4

NASA Technical Reports Server (NTRS)

2002-01-01

The contents include: 1) Application Briefs; 2) Sneak Preview of Sensors Expo; 3) The Complexity of the Diagnosis Problem; 4) Design Concepts for the ISS TransHab Module; 5) Characteristics of Supercritical Transitional Mixing Layers; 6) Electrometer for Triboelectric Evaluation of Materials; 7) Infrared CO2 Sensor With Built-In Calibration Chambers; 8) Solid-State Potentiometric CO Sensor; 9) Planetary Rover Absolute Heading Detection Using a Sun Sensor; 10) Concept for Utilizing Full Areas of STJ Photodetector Arrays; 11) Development of Cognitive Sensors; 12) Enabling Higher-Voltage Operation of SOl CMOS Transistors; 13) Estimating Antenna-Pointing Errors From Beam Squints; 14) Advanced-Fatigue-Crack-Growth and Fracture- Mechanics Program; 15) Software for Sequencing Spacecraft Actions; 16) Program Distributes and Tracks Organizational Memoranda; 16) Flat Membrane Device for Dehumidification of Air; 17) Inverted Hindle Mount Reduces Sag of a Large, Precise Mirror; 18) Heart-Pump-Outlet/Cannula Coupling; 19) Externally Triggered Microcapsules Release Drugs In Situ; 20) Combinatorial Drug Design Augmented by Information Theory; 21) Multiple-Path-Length Optical Absorbance Cell; 22) Model of a Fluidized Bed Containing a Mixture of Particles; 23) Refractive Secondary Concentrators for Solar Thermal Systems; 24) Cold Flow Calorimeter; 25) Methodology for Tracking Hazards and Predicting Failures; 26) Estimating Heterodyne-Interferometer Polarization Leakage; 27) An Efficient Algorithm for Propagation of Temporal- Constraint Networks; 28) Software for Continuous Replanning During Execution; 29) Surface-Launched Explorers for Reconnaissance/Scouting; 30) Firmware for a Small Motion-Control Processor; 31) Gear Bearings and Gear-Bearing Transmissions; and 32) Linear Dynamometer With Variable Stroke and Frequency.

Stroke Prevalence, Mortality and Disability-Adjusted Life Years in Children and Youth Aged 0-19 Years: Data from the Global and Regional Burden of Stroke 2013.

PubMed

Krishnamurthi, Rita V; deVeber, Gabrielle; Feigin, Valery L; Barker-Collo, Suzanne; Fullerton, Heather; Mackay, Mark T; O'Callahan, Finbar; Lindsay, M Patrice; Kolk, Anneli; Lo, Warren; Shah, Priyanka; Linds, Alexandra; Jones, Kelly; Parmar, Priya; Taylor, Steve; Norrving, Bo; Mensah, George A; Moran, Andrew E; Naghavi, Mohsen; Forouzanfar, Mohammed H; Nguyen, Grant; Johnson, Catherine O; Vos, Theo; Murray, Christopher J L; Roth, Gregory A

2015-01-01

There is increasing recognition of stroke as an important contributor to childhood morbidity and mortality. Current estimates of global childhood stroke burden and its temporal trends are sparse. Accurate and up-to-date estimates of childhood stroke burden are important for planning research and the resulting evidence-based strategies for stroke prevention and management. To estimate the prevalence, mortality and disability-adjusted life years (DALYs) for ischemic stroke (IS), hemorrhagic stroke (HS) and all stroke types combined globally from 1990 to 2013. Stroke prevalence, mortality and DALYs were estimated using the Global Burden of Disease 2013 methods. All available data on stroke-related incidence, prevalence, excess mortality and deaths were collected. Statistical models and country-level covariates were employed to produce comprehensive and consistent estimates of prevalence and mortality. Stroke-specific disability weights were used to estimate years lived with disability and DALYs. Means and 95% uncertainty intervals (UIs) were calculated for prevalence, mortality and DALYs. The median of the percent change and 95% UI were determined for the period from 1990 to 2013. In 2013, there were 97,792 (95% UI 90,564-106,016) prevalent cases of childhood IS and 67,621 (95% UI 62,899-72,214) prevalent cases of childhood HS, reflecting an increase of approximately 35% in the absolute numbers of prevalent childhood strokes since 1990. There were 33,069 (95% UI 28,627-38,998) deaths and 2,615,118 (95% UI 2,265,801-3,090,822) DALYs due to childhood stroke in 2013 globally, reflecting an approximately 200% decrease in the absolute numbers of death and DALYs in childhood stroke since 1990. Between 1990 and 2013, there were significant increases in the global prevalence rates of childhood IS, as well as significant decreases in the global death rate and DALYs rate of all strokes in those of age 0-19 years. While prevalence rates for childhood IS and HS decreased significantly in developed countries, a decline was seen only in HS, with no change in prevalence rates of IS, in developing countries. The childhood stroke DALY rates in 2013 were 13.3 (95% UI 10.6-17.1) for IS and 92.7 (95% UI 80.5-109.7) for HS per 100,000. While the prevalence of childhood IS compared to childhood HS was similar globally, the death rate and DALY rate of HS was 6- to 7-fold higher than that of IS. In 2013, the prevalence rate of both childhood IS and HS was significantly higher in developed countries than in developing countries. Conversely, both death and DALY rates for all stroke types were significantly lower in developed countries than in developing countries in 2013. Men showed a trend toward higher childhood stroke death rates (1.5 (1.3-1.8) per 100,000) than women (1.1 (0.9-1.5) per 100,000) and higher childhood stroke DALY rates (120.1 (100.8-143.4) per 100,000) than women (90.9 (74.6-122.4) per 100,000) globally in 2013. Globally, between 1990 and 2013, there was a significant increase in the absolute number of prevalent childhood strokes, while absolute numbers and rates of both deaths and DALYs declined significantly. The gap in childhood stroke burden between developed and developing countries is closing; however, in 2013, childhood stroke burden in terms of absolute numbers of prevalent strokes, deaths and DALYs remained much higher in developing countries. There is an urgent need to address these disparities with both global and country-level initiatives targeting prevention as well as improved access to acute and chronic stroke care. © 2015 S. Karger AG, Basel.

High Risk of Seizures and Epilepsy after Decompressive Hemicraniectomy for Malignant Middle Cerebral Artery Stroke

PubMed Central

Brondani, Rosane; Garcia de Almeida, Andrea; Abrahim Cherubini, Pedro; Mandelli Mota, Suelen; de Alencastro, Luiz Carlos; Antunes, Apio Cláudio Martins; Bianchin Muxfeldt, Marino

2017-01-01

Background Decompressive hemicraniectomy (DHC) is a life-saving procedure for treatment of large malignant middle cerebral artery (MCA) strokes. Post-stroke epilepsy is an additional burden for these patients, but its incidence and the risk factors for its development have been poorly investigated. Objective To report the prevalence and risk factors for post-stroke seizures and post-stroke epilepsy after DHC for treatment of large malignant MCA strokes in a cohort of 36 patients. Methods In a retrospective cohort study of 36 patients we report the timing and incidence of post-stroke epilepsy. We analyzed if age, sex, vascular risk factors, side of ischemia, reperfusion therapy, stroke etiology, extension of stroke, hemorrhagic transformation, ECASS scores, National Institutes of Health Stroke Scale (NIHSS) scores, or modified Rankin scores were risk factors for seizure or epilepsy after DHC for treatment of large MCA strokes. Results The mean patient follow-up time was 1,086 days (SD = 1,172). Out of 36 patients, 9 (25.0%) died before being discharged. After 1 year, a total of 11 patients (30.6%) had died, but 22 (61.1%) of them had a modified Rankin score ≤4. Thirteen patients (36.1%) developed seizures within the first week after stroke. Seizures occurred in 22 (61.1%) of 36 patients (95% CI = 45.17–77.03%). Out of 34 patients who survived the acute period, 19 (55.9%) developed epilepsy after MCA infarcts and DHC (95% CI = 39.21–72.59%). In this study, no significant differences were observed between the patients who developed seizures or epilepsy and those who remained free of seizures or epilepsy regarding age, sex, side of stroke, presence of the clinical risk factors studied, hemorrhagic transformation, time of craniectomy, and Rankin score after 1 year of stroke. Conclusion The incidence of seizures and epilepsy after malignant MCA infarcts submitted to DHC might be very high. Seizure might occur precociously in patients who are not submitted to anticonvulsant prophylaxis. The large stroke volume and the large cortical ischemic area seem to be the main risk factors for seizure or epilepsy development in this subtype of stroke. PMID:28359069

A review: flexible, stretchable multifunctional sensors and actuators for heart arrhythmia therapy

NASA Astrophysics Data System (ADS)

Kang, Seung-Jo; Pak, James Jungho

2017-12-01

Cardiovascular disease is a very serious disease which results in about 30% of all global mortality. Atrial fibrillation (AF) causes rapid and irregular contractions resulting in stroke and cardiac arrest. AF is caused by abnormality of the heartbeat controlling electrical signal. Catheter ablation (CA) is often used to treat and remove the abnormal electrical source from the heart but it has limitations in sensing capability and spatial coverage. To overcome the limitations of the CA, new devices for improving the spatial capability have been reported. One of the most impressive methods is wrapping the heart surface with a flexible/stretchable film with an array of high-density multifunctional micro-sensors and actuators. With this technique, the overall heart surface may be diagnosed in real time and the AF may be treated much more effectively. The data acquisition from the array of multifunctional sensors is also very important for making the new devices useful. To operate the implanted device system, a battery is mostly used and it should be avoided to replace the battery by surgery. Therefore, various energy harvesting techniques or wireless energy transfer techniques to continuously feed the power to the system are under investigation. The development of these technologies was reviewed, and the current level of technology was reviewed and summarized.

Altered motor unit discharge patterns in paretic muscles of stroke survivors assessed using surface electromyography.

PubMed

Hu, Xiaogang; Suresh, Aneesha K; Rymer, William Z; Suresh, Nina L

2016-08-01

Hemispheric stroke survivors often show impairments in voluntary muscle activation. One potential source of these impairments could come from altered control of muscle, via disrupted motor unit (MU) firing patterns. In this study, we sought to determine whether MU firing patterns are modified on the affected side of stroke survivors, as compared with the analogous contralateral muscle. Using a novel surface electromyogram (EMG) sensor array, coupled with advanced template recognition software (dEMG) we recorded surface EMG signals over the first dorsal interosseous (FDI) muscle on both paretic and contralateral sides. Recordings were made as stroke survivors produced isometric index finger abductions over a large force range (20%-60% of maximum). Utilizing the dEMG algorithm, MU firing rates, recruitment thresholds, and action potential amplitudes were estimated for concurrently active MUs in each trial. Our results reveal significant changes in the firing rate patterns in paretic FDI muscle, in that the discharge rates, characterized in relation to recruitment force threshold and to MU size, were less clearly correlated with recruitment force than in contralateral FDI muscles. Firing rates in the affected muscle also did not modulate systematically with the level of voluntary muscle contraction, as would be expected in intact muscles. These disturbances in firing properties also correlated closely with the impairment of muscle force generation. Our results provide strong evidence of disruptions in MU firing behavior in paretic muscles after a hemispheric stroke, suggesting that modified control of the spinal motoneuron pool could be a contributing factor to muscular weakness in stroke survivors.

Altered motor unit discharge patterns in paretic muscles of stroke survivors assessed using surface electromyography

NASA Astrophysics Data System (ADS)

Hu, Xiaogang; Suresh, Aneesha K.; Rymer, William Z.; Suresh, Nina L.

2016-08-01

Objective. Hemispheric stroke survivors often show impairments in voluntary muscle activation. One potential source of these impairments could come from altered control of muscle, via disrupted motor unit (MU) firing patterns. In this study, we sought to determine whether MU firing patterns are modified on the affected side of stroke survivors, as compared with the analogous contralateral muscle. Approach. Using a novel surface electromyogram (EMG) sensor array, coupled with advanced template recognition software (dEMG) we recorded surface EMG signals over the first dorsal interosseous (FDI) muscle on both paretic and contralateral sides. Recordings were made as stroke survivors produced isometric index finger abductions over a large force range (20%-60% of maximum). Utilizing the dEMG algorithm, MU firing rates, recruitment thresholds, and action potential amplitudes were estimated for concurrently active MUs in each trial. Main results. Our results reveal significant changes in the firing rate patterns in paretic FDI muscle, in that the discharge rates, characterized in relation to recruitment force threshold and to MU size, were less clearly correlated with recruitment force than in contralateral FDI muscles. Firing rates in the affected muscle also did not modulate systematically with the level of voluntary muscle contraction, as would be expected in intact muscles. These disturbances in firing properties also correlated closely with the impairment of muscle force generation. Significance. Our results provide strong evidence of disruptions in MU firing behavior in paretic muscles after a hemispheric stroke, suggesting that modified control of the spinal motoneuron pool could be a contributing factor to muscular weakness in stroke survivors.

Improving the development, monitoring and reporting of stroke rehabilitation research: Consensus-based core recommendations from the Stroke Recovery and Rehabilitation Roundtable.

PubMed

Walker, Marion F; Hoffmann, Tammy C; Brady, Marian C; Dean, Catherine M; Eng, Janice J; Farrin, Amanda J; Felix, Cynthia; Forster, Anne; Langhorne, Peter; Lynch, Elizabeth A; Radford, Kathryn A; Sunnerhagen, Katharina S; Watkins, Caroline L

2017-07-01

Recent reviews have demonstrated that the quality of stroke rehabilitation research has continued to improve over the last four decades but despite this progress, there are still many barriers in moving the field forward. Rigorous development, monitoring and complete reporting of interventions in stroke trials are essential in providing rehabilitation evidence that is robust, meaningful and implementable. An international partnership of stroke rehabilitation experts committed to develop consensus-based core recommendations with a remit of addressing the issues identified as limiting stroke rehabilitation research in the areas of developing, monitoring and reporting stroke rehabilitation interventions. Work exploring each of the three areas took place via multiple teleconferences and a two-day meeting in Philadelphia in May 2016. A total of 15 recommendations were made. To validate the need for the recommendations, the group reviewed all stroke rehabilitation trials published in 2015 (n = 182 papers). Our review highlighted that the majority of publications did not clearly describe how interventions were developed or monitored during the trial. In particular, under-reporting of the theoretical rationale for the intervention and the components of the intervention call into question many interventions that have been evaluated for efficacy. More trials were found to have addressed the reporting of interventions recommendations than those related to development or monitoring. Nonetheless, the majority of reporting recommendations were still not adequately described. To progress the field of stroke rehabilitation research and to ensure stroke patients receive optimal evidence-based clinical care, we urge the research community to endorse and adopt our recommendations.

Evaluation of body temperature in individuals with stroke.

PubMed

Alfieri, Fábio Marcon; Massaro, Ayrton Roberto; Filippo, Thais Raquel; Portes, Leslie Andrews; Battistella, Linamara Rizzo

2017-01-01

A stroke can cause alterations in thermal sensitivity. to verify the conditions of body temperature in hemiplegic patients after stroke as compared to healthy individuals, as well as establish relations between thermal sensitivity and gender, age, Body Mass Index (BMI), plegic side, time after stroke, reports of thermal alterations and the motricity of patients with stroke sequelae. This cross-sectional study included 100 patients (55.6±13 years) with ischemic or hemorrhagic stroke sequelae with unilateral hemiparesis and thirty healthy subjects (55±12.9 years). Individuals with nervous peripheral lesions, diabetes, peripheral vascular diseases or tumors were not included in this study. The volunteers underwent axillary temperature evaluations with the use of a cutaneous thermometer and evaluations of cutaneous temperature of hands and feet as measured by infrared thermography captured by an infrared sensor (ThermaCAMTM SC 500-FLIR Systems). The mean temperature (°C) was analyzed with the SigmaStat 3.5 statistical package. The results have shown that healthy individuals have similar temperatures on either side of the body. The hemiplegic subjects presented a lower temperature on the plegic side and compared to the healthy subjects, both feet of the hemiparetic individuals were colder. The results have also shown that age, body mass index, and the time after stroke have no influence on the alterations in temperature. Regarding the paretic side, individuals with hemiplegia on the right side (right foot) had a lower temperature than those affected on the left side. Motricity was not related to any difference in temperature between the limbs and the reports of temperature differences had no relation with the actual differences found in the study. Healthy individuals have temperature symmetry between between sides of the body, while individuals with stroke sequelae present lower temperature in the paretic side, especially on their feet.

Stroke: Working toward a Prioritized World Agenda

PubMed Central

Hachinski, Vladimir; Donnan, Geoffrey A.; Gorelick, Philip B.; Hacke, Werner; Cramer, Steven C.; Kaste, Markku; Fisher, Marc; Brainin, Michael; Buchan, Alastair M.; Lo, Eng H.; Skolnick, Brett E.; Furie, Karen L.; Hankey, Graeme J.; Kivipelto, Miia; Morris, John; Rothwell, Peter M.; Sacco, Ralph L.; Smith, Sidney C.; Wang, Yulun; Bryer, Alan; Ford, Gary A.; Iadecola, Costantino; Martins, Sheila C.O.; Saver, Jeff; Skvortsova, Veronika; Bayley, Mark; Bednar, Martin M.; Duncan, Pamela; Enney, Lori; Finklestein, Seth; Jones, Theresa A.; Kalra, Lalit; Kleim, Jeff; Nitkin, Ralph; Teasell, Robert; Weiller, Cornelius; Desai, Bhupat; Goldberg, Mark P.; Heiss, Wolf-Dieter; Saarelma, Osmo; Schwamm, Lee H.; Shinohara, Yukito; Trivedi, Bhargava; Wahlgren, Nils; Wong, Lawrence K.; Hakim, Antoine; Norrving, Bo; Prudhomme, Stephen; Bornstein, Natan M.; Davis, Stephen M.; Goldstein, Larry B.; Leys, Didier; Tuomilehto, Jaakko

2013-01-01

Background and Purpose The aim of the Synergium was to devise and prioritize new ways of accelerating progress in reducing the risks, effects, and consequences of stroke. Methods Preliminary work was performed by 7 working groups of stroke leaders followed by a synergium (a forum for working synergistically together) with approximately 100 additional participants. The resulting draft document had further input from contributors outside the synergium. Results Recommendations of the Synergium are: Basic Science, Drug Development and Technology: There is a need to develop: (1) New systems of working together to break down the prevalent ‘silo’ mentality; (2) New models of vertically integrated basic, clinical, and epidemiological disciplines; and (3) Efficient methods of identifying other relevant areas of science. Stroke Prevention: (1) Establish a global chronic disease prevention initiative with stroke as a major focus. (2) Recognize not only abrupt clinical stroke, but subtle subclinical stroke, the commonest type of cerebrovascular disease, leading to impairments of executive function. (3) Develop, implement and evaluate a population approach for stroke prevention. (4) Develop public health communication strategies using traditional and novel (e.g., social media/marketing) techniques. Acute Stroke Management: Continue the establishment of stroke centers, stroke units, regional systems of emergency stroke care and telestroke networks. Brain Recovery and Rehabilitation: (1) Translate best neuroscience, including animal and human studies, into poststroke recovery research and clinical care. (2) Standardize poststroke rehabilitation based on best evidence. (3) Develop consensus on, then implementation of, standardized clinical and surrogate assessments. (4) Carry out rigorous clinical research to advance stroke recovery. Into the 21st Century: Web, Technology and Communications: (1) Work toward global unrestricted access to stroke-related information. (2) Build centralized electronic archives and registries. Foster Cooperation Among Stakeholders (large stroke organizations, nongovernmental organizations, governments, patient organizations and industry) to enhance stroke care. Educate and energize professionals, patients, the public and policy makers by using a ‘Brain Health’ concept that enables promotion of preventive measures. Conclusions To accelerate progress in stroke, we must reach beyond the current status scientifically, conceptually, and pragmatically. Advances can be made not only by doing, but ceasing to do. Significant savings in time, money, and effort could result from discontinuing practices driven by unsubstantiated opinion, unproven approaches, and financial gain. Systematic integration of knowledge into programs coupled with careful evaluation can speed the pace of progress PMID:20636706

Stroke: Working toward a Prioritized World Agenda

PubMed Central

Hachinski, Vladimir; Donnan, Geoffrey A.; Gorelick, Philip B.; Hacke, Werner; Cramer, Steven C.; Kaste, Markku; Fisher, Marc; Brainin, Michael; Buchan, Alastair M.; Lo, Eng H.; Skolnick, Brett E.; Furie, Karen L.; Hankey, Graeme J.; Kivipelto, Miia; Morris, John; Rothwell, Peter M.; Sacco, Ralph L.; Smith, Jr., Sidney C.; Wang, Yulun; Bryer, Alan; Ford, Gary A.; Iadecola, Costantino; Martins, Sheila C.O.; Saver, Jeff; Skvortsova, Veronika; Bayley, Mark; Bednar, Martin M.; Duncan, Pamela; Enney, Lori; Finklestein, Seth; Jones, Theresa A.; Kalra, Lalit; Kleim, Jeff; Nitkin, Ralph; Teasell, Robert; Weiller, Cornelius; Desai, Bhupat; Goldberg, Mark P.; Heiss, Wolf-Dieter; Saarelma, Osmo; Schwamm, Lee H.; Shinohara, Yukito; Trivedi, Bhargava; Wahlgren, Nils; Wong, Lawrence K.; Hakim, Antoine; Norrving, Bo; Prudhomme, Stephen; Bornstein, Natan M.; Davis, Stephen M.; Goldstein, Larry B.; Leys, Didier; Tuomilehto, Jaakko

2010-01-01

Background and Purpose The aim of the Synergium was to devise and prioritize new ways of accelerating progress in reducing the risks, effects, and consequences of stroke. Methods Preliminary work was performed by 7 working groups of stroke leaders followed by a synergium (a forum for working synergistically together) with approximately 100 additional participants. The resulting draft document had further input from contributors outside the synergium. Results Recommendations of the Synergium are: Basic Science, Drug Development and Technology: There is a need to develop: (1) New systems of working together to break down the prevalent ‘silo’ mentality; (2) New models of vertically integrated basic, clinical, and epidemiological disciplines; and (3) Efficient methods of identifying other relevant areas of science. Stroke Prevention: (1) Establish a global chronic disease prevention initiative with stroke as a major focus. (2) Recognize not only abrupt clinical stroke, but subtle subclinical stroke, the commonest type of cerebrovascular disease, leading to impairments of executive function. (3) Develop, implement and evaluate a population approach for stroke prevention. (4) Develop public health communication strategies using traditional and novel (e.g., social media/marketing) techniques. Acute Stroke Management: Continue the establishment of stroke centers, stroke units, regional systems of emergency stroke care and telestroke networks. Brain Recovery and Rehabilitation: (1) Translate best neuroscience, including animal and human studies, into poststroke recovery research and clinical care. (2) Standardize poststroke rehabilitation based on best evidence. (3) Develop consensus on, then implementation of, standardized clinical and surrogate assessments. (4) Carry out rigorous clinical research to advance stroke recovery. Into the 21st Century: Web, Technology and Communications: (1) Work toward global unrestricted access to stroke-related information. (2) Build centralized electronic archives and registries. Foster Cooperation Among Stakeholders (large stroke organizations, nongovernmental organizations, governments, patient organizations and industry) to enhance stroke care. Educate and energize professionals, patients, the public and policy makers by using a ‘Brain Health’ concept that enables promotion of preventive measures. Conclusions To accelerate progress in stroke, we must reach beyond the current status scientifically, conceptually, and pragmatically. Advances can be made not only by doing, but ceasing to do. Significant savings in time, money, and effort could result from discontinuing practices driven by unsubstantiated opinion, unproven approaches, and financial gain. Systematic integration of knowledge into programs coupled with careful evaluation can speed the pace of progress. PMID:20516682

Stroke: Working Toward a Prioritized World Agenda

PubMed Central

Hachinski, Vladimir; Donnan, Geoffrey A.; Gorelick, Philip B.; Hacke, Werner; Cramer, Steven C.; Kaste, Markku; Fisher, Marc; Brainin, Michael; Buchan, Alastair M.; Lo, Eng H.; Skolnick, Brett E.; Furie, Karen L.; Hankey, Graeme J.; Kivipelto, Miia; Morris, John; Rothwell, Peter M.; Sacco, Ralph L.; Smith, Sidney C.; Wang, Yulun; Bryer, Alan; Ford, Gary A.; Iadecola, Costantino; Martins, Sheila C.O.; Saver, Jeff; Skvortsova, Veronika; Bayley, Mark; Bednar, Martin M.; Duncan, Pamela; Enney, Lori; Finklestein, Seth; Jones, Theresa A.; Kalra, Lalit; Kleim, Jeff; Nitkin, Ralph; Teasell, Robert; Weiller, Cornelius; Desai, Bhupat; Goldberg, Mark P.; Heiss, Wolf-Dieter; Saarelma, Osmo; Schwamm, Lee H.; Shinohara, Yukito; Trivedi, Bhargava; Wahlgren, Nils; Wong, Lawrence K.; Hakim, Antoine; Norrving, Bo; Prudhomme, Stephen; Bornstein, Natan M.; Davis, Stephen M.; Edin, FRCP; Goldstein, Larry B.; Leys, Didier; Tuomilehto, Jaakko

2013-01-01

Background and Purpose The aim of the Synergium was to devise and prioritize new ways of accelerating progress in reducing the risks, effects, and consequences of stroke. Methods Preliminary work was performed by 7 working groups of stroke leaders followed by a synergium (a forum for working synergistically together) with approximately 100 additional participants. The resulting draft document had further input from contributors outside the synergium. Results Recommendations of the Synergium are: Basic Science, Drug Development and Technology: There is a need to develop: (1) New systems of working together to break down the prevalent “silo” mentality; (2) New models of vertically integrated basic, clinical, and epidemiological disciplines; and (3) Efficient methods of identifying other relevant areas of science. Stroke Prevention: (1) Establish a global chronic disease prevention initiative with stroke as a major focus. (2) Recognize not only abrupt clinical stroke, but subtle subclinical stroke, the commonest type of cerebrovascular disease, leading to impairments of executive function. (3) Develop, implement and evaluate a population approach for stroke prevention. (4) Develop public health communication strategies using traditional and novel (eg, social media/marketing) techniques. Acute Stroke Management: Continue the establishment of stroke centers, stroke units, regional systems of emergency stroke care and telestroke networks. Brain Recovery and Rehabilitation: (1) Translate best neuroscience, including animal and human studies, into poststroke recovery research and clinical care. (2) Standardize poststroke rehabilitation based on best evidence. (3) Develop consensus on, then implementation of, standardized clinical and surrogate assessments. (4) Carry out rigorous clinical research to advance stroke recovery. Into the 21st Century: Web, Technology and Communications: (1) Work toward global unrestricted access to stroke-related information. (2) Build centralized electronic archives and registries. Foster Cooperation Among Stakeholders (large stroke organizations, nongovernmental organizations, governments, patient organizations and industry) to enhance stroke care. Educate and energize professionals, patients, the public and policy makers by using a “Brain Health” concept that enables promotion of preventive measures. Conclusions To accelerate progress in stroke, we must reach beyond the current status scientifically, conceptually, and pragmatically. Advances can be made not only by doing, but ceasing to do. Significant savings in time, money, and effort could result from discontinuing practices driven by unsubstantiated opinion, unproven approaches, and financial gain. Systematic integration of knowledge into programs coupled with careful evaluation can speed the pace of progress. PMID:20498453

Stroke: working toward a prioritized world agenda.

PubMed

Hachinski, Vladimir; Donnan, Geoffrey A; Gorelick, Philip B; Hacke, Werner; Cramer, Steven C; Kaste, Markku; Fisher, Marc; Brainin, Michael; Buchan, Alastair M; Lo, Eng H; Skolnick, Brett E; Furie, Karen L; Hankey, Graeme J; Kivipelto, Miia; Morris, John; Rothwell, Peter M; Sacco, Ralph L; Smith, Sidney C; Wang, Yulun; Bryer, Alan; Ford, Gary A; Iadecola, Costantino; Martins, Sheila C O; Saver, Jeff; Skvortsova, Veronika; Bayley, Mark; Bednar, Martin M; Duncan, Pamela; Enney, Lori; Finklestein, Seth; Jones, Theresa A; Kalra, Lalit; Kleim, Jeff; Nitkin, Ralph; Teasell, Robert; Weiller, Cornelius; Desai, Bhupat; Goldberg, Mark P; Heiss, Wolf-Dieter; Saarelma, Osmo; Schwamm, Lee H; Shinohara, Yukito; Trivedi, Bhargava; Wahlgren, Nils; Wong, Lawrence K; Hakim, Antoine; Norrving, Bo; Prudhomme, Stephen; Bornstein, Natan M; Davis, Stephen M; Goldstein, Larry B; Leys, Didier; Tuomilehto, Jaakko

2010-01-01

The aim of the Synergium was to devise and prioritize new ways of accelerating progress in reducing the risks, effects, and consequences of stroke. Preliminary work was performed by 7 working groups of stroke leaders followed by a synergium (a forum for working synergistically together) with approximately 100 additional participants. The resulting draft document had further input from contributors outside the synergium. Recommendations of the Synergium are: Basic Science, Drug Development and Technology: There is a need to develop: (1) New systems of working together to break down the prevalent 'silo' mentality; (2) New models of vertically integrated basic, clinical, and epidemiological disciplines; and (3) Efficient methods of identifying other relevant areas of science. Stroke Prevention: (1) Establish a global chronic disease prevention initiative with stroke as a major focus. (2) Recognize not only abrupt clinical stroke, but subtle subclinical stroke, the commonest type of cerebrovascular disease, leading to impairments of executive function. (3) Develop, implement and evaluate a population approach for stroke prevention. (4) Develop public health communication strategies using traditional and novel (e.g., social media/marketing) techniques. Acute Stroke Management: Continue the establishment of stroke centers, stroke units, regional systems of emergency stroke care and telestroke networks. Brain Recovery and Rehabilitation: (1) Translate best neuroscience, including animal and human studies, into poststroke recovery research and clinical care. (2) Standardize poststroke rehabilitation based on best evidence. (3) Develop consensus on, then implementation of, standardized clinical and surrogate assessments. (4) Carry out rigorous clinical research to advance stroke recovery. Into the 21st Century: Web, Technology and Communications: (1) Work toward global unrestricted access to stroke-related information. (2) Build centralized electronic archives and registries. Foster Cooperation Among Stakeholders (large stroke organizations, nongovernmental organizations, governments, patient organizations and industry) to enhance stroke care. Educate and energize professionals, patients, the public and policy makers by using a 'Brain Health' concept that enables promotion of preventive measures. To accelerate progress in stroke, we must reach beyond the current status scientifically, conceptually, and pragmatically. Advances can be made not only by doing, but ceasing to do. Significant savings in time, money, and effort could result from discontinuing practices driven by unsubstantiated opinion, unproven approaches, and financial gain. Systematic integration of knowledge into programs coupled with careful evaluation can speed the pace of progress. Copyright (c) 2010 American Heart Association. Inc., S. Karger AG, Basel, and John Wiley & Sons, Inc.

Stroke: working toward a prioritized world agenda.

PubMed

Hachinski, Vladimir; Donnan, Geoffrey A; Gorelick, Philip B; Hacke, Werner; Cramer, Steven C; Kaste, Markku; Fisher, Marc; Brainin, Michael; Buchan, Alastair M; Lo, Eng H; Skolnick, Brett E; Furie, Karen L; Hankey, Graeme J; Kivipelto, Miia; Morris, John; Rothwell, Peter M; Sacco, Ralph L; Smith, Sidney C; Wang, Yulun; Bryer, Alan; Ford, Gary A; Iadecola, Costantino; Martins, Sheila C O; Saver, Jeff; Skvortsova, Veronika; Bayley, Mark; Bednar, Martin M; Duncan, Pamela; Enney, Lori; Finklestein, Seth; Jones, Theresa A; Kalra, Lalit; Kleim, Jeff; Nitkin, Ralph; Teasell, Robert; Weiller, Cornelius; Desai, Bhupat; Goldberg, Mark P; Heiss, Wolf-Dieter; Saarelma, Osmo; Schwamm, Lee H; Shinohara, Yukito; Trivedi, Bhargava; Wahlgren, Nils; Wong, Lawrence K; Hakim, Antoine; Norrving, Bo; Prudhomme, Stephen; Bornstein, Natan M; Davis, Stephen M; Goldstein, Larry B; Leys, Didier; Tuomilehto, Jaakko

2010-06-01

The aim of the Synergium was to devise and prioritize new ways of accelerating progress in reducing the risks, effects, and consequences of stroke. Preliminary work was performed by 7 working groups of stroke leaders followed by a synergium (a forum for working synergistically together) with approximately 100 additional participants. The resulting draft document had further input from contributors outside the synergium. Recommendations of the Synergium are: Basic Science, Drug Development and Technology: There is a need to develop: (1) New systems of working together to break down the prevalent "silo" mentality; (2) New models of vertically integrated basic, clinical, and epidemiological disciplines; and (3) Efficient methods of identifying other relevant areas of science. Stroke Prevention: (1) Establish a global chronic disease prevention initiative with stroke as a major focus. (2) Recognize not only abrupt clinical stroke, but subtle subclinical stroke, the commonest type of cerebrovascular disease, leading to impairments of executive function. (3) Develop, implement and evaluate a population approach for stroke prevention. (4) Develop public health communication strategies using traditional and novel (eg, social media/marketing) techniques. Acute Stroke Management: Continue the establishment of stroke centers, stroke units, regional systems of emergency stroke care and telestroke networks. Brain Recovery and Rehabilitation: (1) Translate best neuroscience, including animal and human studies, into poststroke recovery research and clinical care. (2) Standardize poststroke rehabilitation based on best evidence. (3) Develop consensus on, then implementation of, standardized clinical and surrogate assessments. (4) Carry out rigorous clinical research to advance stroke recovery. Into the 21st Century: Web, Technology and Communications: (1) Work toward global unrestricted access to stroke-related information. (2) Build centralized electronic archives and registries. Foster Cooperation Among Stakeholders (large stroke organizations, nongovernmental organizations, governments, patient organizations and industry) to enhance stroke care. Educate and energize professionals, patients, the public and policy makers by using a "Brain Health" concept that enables promotion of preventive measures. To accelerate progress in stroke, we must reach beyond the current status scientifically, conceptually, and pragmatically. Advances can be made not only by doing, but ceasing to do. Significant savings in time, money, and effort could result from discontinuing practices driven by unsubstantiated opinion, unproven approaches, and financial gain. Systematic integration of knowledge into programs coupled with careful evaluation can speed the pace of progress.

Stroke: working toward a prioritized world agenda.

PubMed

Hachinski, Vladimir; Donnan, Geoffrey A; Gorelick, Philip B; Hacke, Werner; Cramer, Steven C; Kaste, Markku; Fisher, Marc; Brainin, Michael; Buchan, Alastair M; Lo, Eng H; Skolnick, Brett E; Furie, Karen L; Hankey, Graeme J; Kivipelto, Miia; Morris, John; Rothwell, Peter M; Sacco, Ralph L; Smith, Sidney C; Wang, Yulun; Bryer, Alan; Ford, Gary A; Iadecola, Costantino; Martins, Sheila C O; Saver, Jeff; Skvortsova, Veronika; Bayley, Mark; Bednar, Martin M; Duncan, Pamela; Enney, Lori; Finklestein, Seth; Jones, Theresa A; Kalra, Lalit; Kleim, Jeff; Nitkin, Ralph; Teasell, Robert; Weiller, Cornelius; Desai, Bhupat; Goldberg, Mark P; Heiss, Wolf-Dieter; Saarelma, Osmo; Schwamm, Lee H; Shinohara, Yukito; Trivedi, Bhargava; Wahlgren, Nils; Wong, Lawrence K; Hakim, Antoine; Norrving, Bo; Prudhomme, Stephen; Bornstein, Natan M; Davis, Stephen M; Goldstein, Larry B; Leys, Didier; Tuomilehto, Jaakko

2010-08-01

The aim of the Synergium was to devise and prioritize new ways of accelerating progress in reducing the risks, effects, and consequences of stroke. Preliminary work was performed by seven working groups of stroke leaders followed by a synergium (a forum for working synergistically together) with approximately 100 additional participants. The resulting draft document had further input from contributors outside the synergium. Recommendations of the Synergium are: Basic Science, Drug Development and Technology: There is a need to develop: (1) New systems of working together to break down the prevalent 'silo' mentality; (2) New models of vertically integrated basic, clinical, and epidemiological disciplines; and (3) Efficient methods of identifying other relevant areas of science. Stroke Prevention: (1) Establish a global chronic disease prevention initiative with stroke as a major focus. (2) Recognize not only abrupt clinical stroke, but subtle subclinical stroke, the commonest type of cerebrovascular disease, leading to impairments of executive function. (3) Develop, implement and evaluate a population approach for stroke prevention. (4) Develop public health communication strategies using traditional and novel (eg, social media/marketing) techniques. Acute Stroke Management: Continue the establishment of stroke centers, stroke units, regional systems of emergency stroke care and telestroke networks. Brain Recovery and Rehabilitation: (1) Translate best neuroscience, including animal and human studies, into poststroke recovery research and clinical care. (2) Standardize poststroke rehabilitation based on best evidence. (3) Develop consensus on, then implementation of, standardized clinical and surrogate assessments. (4) Carry out rigorous clinical research to advance stroke recovery. Into the 21st Century: Web, Technology and Communications: (1) Work toward global unrestricted access to stroke-related information. (2) Build centralized electronic archives and registries. Foster Cooperation Among Stakeholders (large stroke organizations, nongovernmental organizations, governments, patient organizations and industry) to enhance stroke care. Educate and energize professionals, patients, the public and policy makers by using a 'Brain Health' concept that enables promotion of preventive measures. To accelerate progress in stroke, we must reach beyond the current status scientifically, conceptually, and pragmatically. Advances can be made not only by doing, but ceasing to do. Significant savings in time, money, and effort could result from discontinuing practices driven by unsubstantiated opinion, unproven approaches, and financial gain. Systematic integration of knowledge into programs coupled with careful evaluation can speed the pace of progress.

Development and Validation of a Bilingual Stroke Preparedness Assessment Instrument

PubMed Central

Skolarus, Lesli E.; Mazor, Kathleen M.; Sánchez, Brisa N.; Dome, Mackenzie; Biller, José; Morgenstern, Lewis B.

2017-01-01

Background and Purpose Stroke preparedness interventions are limited by the lack of psychometrically sound intermediate endpoints. We sought to develop and assess the reliability and validity of the video-Stroke Action Test, video-STAT, an English and Spanish video-based test to assess people’s ability to recognize and react to stroke signs. Methods Video-STAT development and testing was divided into four phases: 1) video development and community-generated response options; 2) pilot testing in community health centers; 3) administration in a national sample, bilingual sample and neurologist sample; and 4) administration before and after a stroke preparedness intervention. Results The final version of the video-STAT included 8 videos: 4 acute stroke/emergency, 2 prior stroke/non-emergency, 1 non-stroke/emergency, 1 non-stroke/non-emergency. Acute stroke recognition and action response were queried after each vignette. Video-STAT scoring was based on the acute stroke vignettes only (score range 0–12 best). The national sample consisted of 598 participants, 438 who took the video-STAT in English and 160 who took the video-STAT in Spanish. There was adequate internal consistency (Cronbach’s alpha=0.72). The average video-STAT score was 5.6 (sd=3.6) while the average neurologist score was 11.4 (sd=1.3). There was no difference in video-STAT scores between the 116 bilingual video-STAT participants who took the video-STAT in English or Spanish. Compared to baseline scores, the video-STAT scores increased following a stroke preparedness intervention (6.2 vs. 8.9, p<0.01) among a sample of 101 African American adults and youth. Conclusion The video-STAT yields reliable scores that appear to be valid measures of stroke preparedness. PMID:28250199

Shoulder pain and concomitant hand oedema among stroke patients with pronounced arm paresis

PubMed Central

2013-01-01

Background The aim of this prospective study was to identify clinical factors associated with the development of shoulder pain in stroke patients with pronounced arm paresis. Methods At stroke onset, 485 patients were initially assessed in 2007–2009. Sixty-three patients with pronounced arm paresis completed the study, and 21 of these developed shoulder pain. Clinical findings were recorded fortnightly by the attending physiotherapist during hospital stay. Results Hand oedema on the paretic side was more common in patients developing shoulder pain compared with those who did not develop shoulder pain. The onset of shoulder pain was associated with concomitant hand oedema. High NIHSS score was associated with developing shoulder pain. Patients with a history of shoulder pain developed pain earlier than those without previous shoulder pain. Patients with haemorrhagic stroke were significantly more prone to developing shoulder pain. Conclusions One-third of the stroke patients with pronounced arm paresis developed shoulder pain. Concomitant hand oedema seems to be an additional symptom of shoulder injury. Patients with low general status are more vulnerable to develop post-stroke shoulder pain. PMID:24765589

Wearable kinesthetic system for capturing and classifying upper limb gesture in post-stroke rehabilitation.

PubMed

Tognetti, Alessandro; Lorussi, Federico; Bartalesi, Raphael; Quaglini, Silvana; Tesconi, Mario; Zupone, Giuseppe; De Rossi, Danilo

2005-03-02

BACKGROUND: Monitoring body kinematics has fundamental relevance in several biological and technical disciplines. In particular the possibility to exactly know the posture may furnish a main aid in rehabilitation topics. In the present work an innovative and unobtrusive garment able to detect the posture and the movement of the upper limb has been introduced, with particular care to its application in post stroke rehabilitation field by describing the integration of the prototype in a healthcare service. METHODS: This paper deals with the design, the development and implementation of a sensing garment, from the characterization of innovative comfortable and diffuse sensors we used to the methodologies employed to gather information on the posture and movement which derive from the entire garments. Several new algorithms devoted to the signal acquisition, the treatment and posture and gesture reconstruction are introduced and tested. RESULTS: Data obtained by means of the sensing garment are analyzed and compared with the ones recorded using a traditional movement tracking system. CONCLUSION: The main results treated in this work are summarized and remarked. The system was compared with a commercial movement tracking system (a set of electrogoniometers) and it performed the same accuracy in detecting upper limb postures and movements.

Phytochemicals in Ischemic Stroke.

PubMed

Kim, Joonki; Fann, David Yang-Wei; Seet, Raymond Chee Seong; Jo, Dong-Gyu; Mattson, Mark P; Arumugam, Thiruma V

2016-09-01

Stroke is the second foremost cause of mortality worldwide and a major cause of long-term disability. Due to changes in lifestyle and an aging population, the incidence of stroke continues to increase and stroke mortality predicted to exceed 12 % by the year 2030. However, the development of pharmacological treatments for stroke has failed to progress much in over 20 years since the introduction of the thrombolytic drug, recombinant tissue plasminogen activator. These alarming circumstances caused many research groups to search for alternative treatments in the form of neuroprotectants. Here, we consider the potential use of phytochemicals in the treatment of stroke. Their historical use in traditional medicine and their excellent safety profile make phytochemicals attractive for the development of therapeutics in human diseases. Emerging findings suggest that some phytochemicals have the ability to target multiple pathophysiological processes involved in stroke including oxidative stress, inflammation and apoptotic cell death. Furthermore, epidemiological studies suggest that the consumption of plant sources rich in phytochemicals may reduce stroke risk, and so reinforce the possibility of developing preventative or neuroprotectant therapies for stroke. In this review, we describe results of preclinical studies that demonstrate beneficial effects of phytochemicals in experimental models relevant to stroke pathogenesis, and we consider their possible mechanisms of action.

Users perspectives on interactive distance technology enabling home-based motor training for stroke patients.

PubMed

Ehn, Maria; Hansson, Pär; Sjölinder, Marie; Boman, Inga-Lill; Folke, Mia; Sommerfeld, Disa; Borg, Jörgen; Palmcrantz, Susanne

2015-01-01

The aim of this work has been to develop a technical support enabling home-based motor training after stroke. The basis for the work plan has been to develop an interactive technical solution supporting three different groups of stroke patients: (1) patients with stroke discharged from hospital with support from neuro team; (2) patients with stroke whose support from neuro team will be phased out and (3) patients living with impaired motor functions long-term. The technology has been developed in close collaboration with end-users using a method earlier evaluated and described [12]. This paper describes the main functions of the developed technology. Further, results from early user-tests with end-users, performed to identify needs for improvements to be carried out during further technical development. The developed technology will be tested further in a pilot study of the safety and, usefulness of the technology when applied as a support for motor training in three different phases of the post-stroke rehabilitation process.

External force/velocity control for an autonomous rehabilitation robot

NASA Astrophysics Data System (ADS)

Saekow, Peerayuth; Neranon, Paramin; Smithmaitrie, Pruittikorn

2018-01-01

Stroke is a primary cause of death and the leading cause of permanent disability in adults. There are many stroke survivors, who live with a variety of levels of disability and always need rehabilitation activities on daily basis. Several studies have reported that usage of rehabilitation robotic devices shows the better improvement outcomes in upper-limb stroke patients than the conventional therapy-nurses or therapists actively help patients with exercise-based rehabilitation. This research focuses on the development of an autonomous robotic trainer designed to guide a stroke patient through an upper-limb rehabilitation task. The robotic device was designed and developed to automate the reaching exercise as mentioned. The designed robotic system is made up of a four-wheel omni-directional mobile robot, an ATI Gamma multi-axis force/torque sensor used to measure contact force and a microcontroller real-time operating system. Proportional plus Integral control was adapted to control the overall performance and stability of the autonomous assistive robot. External force control was successfully implemented to establish the behavioral control strategy for the robot force and velocity control scheme. In summary, the experimental results indicated satisfactorily stable performance of the robot force and velocity control can be considered acceptable. The gain tuning for proportional integral (PI) velocity control algorithms was suitably estimated using the Ziegler-Nichols method in which the optimized proportional and integral gains are 0.45 and 0.11, respectively. Additionally, the PI external force control gains were experimentally tuned using the trial and error method based on a set of experiments which allow a human participant moves the robot along the constrained circular path whilst attempting to minimize the radial force. The performance was analyzed based on the root mean square error (E_RMS) of the radial forces, in which the lower the variation in radial forces, the better the performance of the system. The outstanding performance of the tests as specified by the E_RMS of the radial force was observed with proportional and integral gains of Kp = 0.7 and Ki = 0.75, respectively.

The Riks-Stroke story: building a sustainable national register for quality assessment of stroke care.

PubMed

Asplund, Kjell; Hulter Åsberg, Kerstin; Appelros, Peter; Bjarne, Daniela; Eriksson, Marie; Johansson, Asa; Jonsson, Fredrik; Norrving, Bo; Stegmayr, Birgitta; Terént, Andreas; Wallin, Sari; Wester, Per-Olov

2011-04-01

Riks-Stroke, the Swedish Stroke Register, is the world's longest-running national stroke quality register (established in 1994) and includes all 76 hospitals in Sweden admitting acute stroke patients. The development and maintenance of this sustainable national register is described. Riks-Stroke includes information on the quality of care during the acute phase, rehabilitation and secondary prevention of stroke, as well as data on community support. Riks-Stroke is unique among stroke quality registers in that patients are followed during the first year after stroke. The data collected describe processes, and medical and patient-reported outcome measurements. The register embraces most of the dimensions of health-care quality (evidence-based, safe, provided in time, distributed fairly and patient oriented). Annually, approximately 25,000 patients are included. In 2009, approximately 320,000 patients had been accumulated (mean age 76-years). The register is estimated to cover 82% of all stroke patients treated in Swedish hospitals. Among critical issues when building a national stroke quality register, the delicate balance between simplicity and comprehensiveness is emphasised. Future developments include direct transfer of data from digital medical records to Riks-Stroke and comprehensive strategies to use the information collected to rapidly implement new evidence-based techniques and to eliminate outdated methods in stroke care. It is possible to establish a sustainable quality register for stroke at the national level covering all hospitals admitting acute stroke patients. Riks-Stroke is fulfilling its main goals to support continuous quality improvement of Swedish stroke services and serve as an instrument for following up national stroke guidelines. © 2010 The Authors. International Journal of Stroke © 2010 World Stroke Organization.

Robotic Mirror Therapy System for Functional Recovery of Hemiplegic Arms.

PubMed

Beom, Jaewon; Koh, Sukgyu; Nam, Hyung Seok; Kim, Wonshik; Kim, Yoonjae; Seo, Han Gil; Oh, Byung-Mo; Chung, Sun Gun; Kim, Sungwan

2016-08-15

Mirror therapy has been performed as effective occupational therapy in a clinical setting for functional recovery of a hemiplegic arm after stroke. It is conducted by eliciting an illusion through use of a mirror as if the hemiplegic arm is moving in real-time while moving the healthy arm. It can facilitate brain neuroplasticity through activation of the sensorimotor cortex. However, conventional mirror therapy has a critical limitation in that the hemiplegic arm is not actually moving. Thus, we developed a real-time 2-axis mirror robot system as a simple add-on module for conventional mirror therapy using a closed feedback mechanism, which enables real-time movement of the hemiplegic arm. We used 3 Attitude and Heading Reference System sensors, 2 brushless DC motors for elbow and wrist joints, and exoskeletal frames. In a feasibility study on 6 healthy subjects, robotic mirror therapy was safe and feasible. We further selected tasks useful for activities of daily living training through feedback from rehabilitation doctors. A chronic stroke patient showed improvement in the Fugl-Meyer assessment scale and elbow flexor spasticity after a 2-week application of the mirror robot system. Robotic mirror therapy may enhance proprioceptive input to the sensory cortex, which is considered to be important in neuroplasticity and functional recovery of hemiplegic arms. The mirror robot system presented herein can be easily developed and utilized effectively to advance occupational therapy.

Preliminary analysis on faint luminous lightning events recorded by multiple high speed cameras

NASA Astrophysics Data System (ADS)

Alves, J.; Saraiva, A. V.; Pinto, O.; Campos, L. Z.; Antunes, L.; Luz, E. S.; Medeiros, C.; Buzato, T. S.

2013-12-01

The objective of this work is the study of some faint luminous events produced by lightning flashes that were recorded simultaneously by multiple high-speed cameras during the previous RAMMER (Automated Multi-camera Network for Monitoring and Study of Lightning) campaigns. The RAMMER network is composed by three fixed cameras and one mobile color camera separated by, in average, distances of 13 kilometers. They were located in the Paraiba Valley (in the cities of São José dos Campos and Caçapava), SP, Brazil, arranged in a quadrilateral shape, centered in São José dos Campos region. This configuration allowed RAMMER to see a thunderstorm from different angles, registering the same lightning flashes simultaneously by multiple cameras. Each RAMMER sensor is composed by a triggering system and a Phantom high-speed camera version 9.1, which is set to operate at a frame rate of 2,500 frames per second with a lens Nikkor (model AF-S DX 18-55 mm 1:3.5 - 5.6 G in the stationary sensors, and a lens model AF-S ED 24 mm - 1:1.4 in the mobile sensor). All videos were GPS (Global Positioning System) time stamped. For this work we used a data set collected in four RAMMER manual operation days in the campaign of 2012 and 2013. On Feb. 18th the data set is composed by 15 flashes recorded by two cameras and 4 flashes recorded by three cameras. On Feb. 19th a total of 5 flashes was registered by two cameras and 1 flash registered by three cameras. On Feb. 22th we obtained 4 flashes registered by two cameras. Finally, in March 6th two cameras recorded 2 flashes. The analysis in this study proposes an evaluation methodology for faint luminous lightning events, such as continuing current. Problems in the temporal measurement of the continuing current can generate some imprecisions during the optical analysis, therefore this work aim to evaluate the effects of distance in this parameter with this preliminary data set. In the cases that include the color camera we analyzed the RGB mode (red, green, blue) and compared them with the data provided by the black and white cameras for the same event and the influence of these parameters with the luminosity intensity of the flashes. Two peculiar cases presented, from the data obtained at one site, a stroke, some continuing current during the interval between the strokes and, then, a subsequent stroke; however, the other site showed that the subsequent stroke was in fact an M-component, since the continuing current had not vanished after its parent stroke. These events generated a dubious classification for the same event that was based only in a visual analysis with high-speed cameras and they were analyzed in this work.

High pro-BNP levels predict the occurrence of atrial fibrillation after cryptogenic stroke.

PubMed

Rodríguez-Yáñez, Manuel; Arias-Rivas, Susana; Santamaría-Cadavid, María; Sobrino, Tomás; Castillo, José; Blanco, Miguel

2013-07-30

Antiplatelets are recommended for secondary prevention in patients with cryptogenic stroke; however, some patients may present with a cardioembolic source that has not been detected, which may modify the treatment. Because high pro-brain natriuretic peptide (BNP) levels are associated with cardioembolic stroke, our objective was to determine whether pro-BNP levels in the acute phase of stroke predict the development of atrial fibrillation (AF) in patients with cryptogenic stroke. A prospective study including patients with cryptogenic stroke was conducted. Demographic data, medical history, and stroke characteristics were assessed at admission. A blood sample was obtained within the first 24 hours from stroke onset to determine pro-BNP levels. Patients were followed by a neurologist at 3 and 6 months and later by a primary care physician for 2 years to evaluate the development of AF. One thousand fifty patients with ischemic stroke were evaluated. Three hundred seventy-two patients (35%) had cryptogenic stroke. One hundred eight patients were excluded from the study, so 264 patients were valid for the analysis. AF was detected in 15 patients (5.6%) during the follow-up. Patients who developed AF were older, had hypertension more frequently, and showed higher levels of pro-BNP. In the logistic regression model, we found that pro-BNP ≥360 pg/mL was the only variable independently associated with the risk of developing AF (odds ratio 5.70, 95% confidence interval 1.11-29.29, p = 0.037). Pro-BNP ≥360 pg/mL increases by 5-fold the possibility of detecting AF during follow-up in patients with cryptogenic stroke.

Difference of motor overflow depending on the impaired or unimpaired hand in stroke patients.

PubMed

Kim, Yushin; Kim, Woo-Sub; Shim, Jae Kun; Suh, Dong Won; Kim, TaeYeong; Yoon, BumChul

2015-02-01

The aim of this study was to investigate the patterns of contralateral motor overflow (i.e. mirror movement) between the homologous body parts on the right and left side, in stroke patients during single-finger and multi-finger maximum force production tasks. Forty subjects, including stroke (n=20) and normal subjects (n=20), participated in this study. The stroke subjects maximally pressed force sensors with their fingers in a flexed position using a single (index, middle, ring, or little) or all fingers (all 4 fingers) using the impaired (IH) or unimpaired (UIH) hand, while the non-patient subjects used their right hands for the same tasks. The maximal voluntary forces in the ipsilateral and unintended pressing forces of each contralateral finger were recorded during the tasks. The magnitude of motor overflow to the contralateral side was calculated using the index of contralateral independence (CI). During the single finger tasks, the finger CI was significantly decreased in the UIH (91%) compared with that in the IH (99%) or normal hands (99%). Likewise, the multiple finger tasks showed that the CI was significantly lower in the UIH (84%) compared with that in the IH (96%) or normal hands (99%). However, the maximal forces were significantly lower in the IH relative to those in the UIH and normal hands. These data demonstrate that stroke patients have greater motor overflow from the UIH to the IH. Copyright © 2014 Elsevier B.V. All rights reserved.

Assessing altered motor unit recruitment patterns in paretic muscles of stroke survivors using surface electromyography

NASA Astrophysics Data System (ADS)

Hu, Xiaogang; Suresh, Aneesha K.; Rymer, William Z.; Suresh, Nina L.

2015-12-01

Objective. The advancement of surface electromyogram (sEMG) recording and signal processing techniques has allowed us to characterize the recruitment properties of a substantial population of motor units (MUs) non-invasively. Here we seek to determine whether MU recruitment properties are modified in paretic muscles of hemispheric stroke survivors. Approach. Using an advanced EMG sensor array, we recorded sEMG during isometric contractions of the first dorsal interosseous muscle over a range of contraction levels, from 20% to 60% of maximum, in both paretic and contralateral muscles of stroke survivors. Using MU decomposition techniques, MU action potential amplitudes and recruitment thresholds were derived for simultaneously activated MUs in each isometric contraction. Main results. Our results show a significant disruption of recruitment organization in paretic muscles, in that the size principle describing recruitment rank order was materially distorted. MUs were recruited over a very narrow force range with increasing force output, generating a strong clustering effect, when referenced to recruitment force magnitude. Such disturbances in MU properties also correlated well with the impairment of voluntary force generation. Significance. Our findings provide direct evidence regarding MU recruitment modifications in paretic muscles of stroke survivors, and suggest that these modifications may contribute to weakness for voluntary contractions.

Assessing altered motor unit recruitment patterns in paretic muscles of stroke survivors using surface electromyography

PubMed Central

Hu, Xiaogang; Suresh, Aneesha K; Rymer, William Z; Suresh, Nina L

2017-01-01

Objective The advancement of surface electromyogram (sEMG) recording and signal processing techniques has allowed us to characterize the recruitment properties of a substantial population of motor units (MUs) non-invasively. Here we seek to determine whether MU recruitment properties are modified in paretic muscles of hemispheric stroke survivors. Approach Using an advanced EMG sensor array, we recorded sEMG during isometric contractions of the first dorsal interosseous muscle over a range of contraction levels, from 20% to 60% of maximum, in both paretic and contralateral muscles of stroke survivors. Using MU decomposition techniques, MU action potential amplitudes and recruitment thresholds were derived for simultaneously activated MUs in each isometric contraction. Main results Our results show a significant disruption of recruitment organization in paretic muscles, in that the size principle describing recruitment rank order was materially distorted. MUs were recruited over a very narrow force range with increasing force output, generating a strong clustering effect, when referenced to recruitment force magnitude. Such disturbances in MU properties also correlated well with the impairment of voluntary force generation. Significance Our findings provide direct evidence regarding MU recruitment modifications in paretic muscles of stroke survivors, and suggest that these modifications may contribute to weakness for voluntary contractions. PMID:26402920

The organisational context of nursing care in stroke units: a case study approach.

PubMed

Burton, Christopher R; Fisher, Andrea; Green, Theresa L

2009-01-01

Internationally the stroke unit is recognised as the evidence-based model for patient management, although clarity about the effective components of stroke units is lacking. Whilst skilled nursing care has been proposed as one component, the theoretical and empirical basis for stroke nursing is limited. We attempted to explore the organisational context of stroke unit nursing, to determine those features that staff perceived to be important in facilitating high quality care. A case study approach was used, that included interviews with nurses and members of the multidisciplinary teams in two Canadian acute stroke units. A total of 20 interviews were completed, transcribed and analysed thematically using the Framework Approach. Trustworthiness was established through the review of themes and their interpretation by members of the stroke units. Nine themes that comprised an organisational context that supported the delivery of high quality nursing care in acute stroke units were identified, and provide a framework for organisational development. The study highlighted the importance of an overarching service model to guide the organisation of care and the development of specialist and advanced nursing roles. Whilst multidisciplinary working appears to be a key component of stroke unit nursing, various organisational challenges to its successful implementation were highlighted. In particular the consequence of differences in the therapeutic approach of nurses and therapy staff needs to be explored in greater depth. Successful teamwork appears to depend on opportunities for the development of relationships between team members as much as the use of formal communication systems and structures. A co-ordinated approach to education and training, clinical leadership, a commitment to research, and opportunities for role and practice development also appear to be key organisational features of stroke unit nursing. Recommendations for the development of stroke nursing leadership and future research into teamwork in stroke settings are made.

Motor recovery monitoring using acceleration measurements in post acute stroke patients.

PubMed

Gubbi, Jayavardhana; Rao, Aravinda S; Fang, Kun; Yan, Bernard; Palaniswami, Marimuthu

2013-04-16

Stroke is one of the major causes of morbidity and mortality. Its recovery and treatment depends on close clinical monitoring by a clinician especially during the first few hours after the onset of stroke. Patients who do not exhibit early motor recovery post thrombolysis may benefit from more aggressive treatment. A novel approach for monitoring stroke during the first few hours after the onset of stroke using a wireless accelerometer based motor activity monitoring system is developed. It monitors the motor activity by measuring the acceleration of the arms in three axes. In the presented proof of concept study, the measured acceleration data is transferred wirelessly using iMote2 platform to the base station that is equipped with an online algorithm capable of calculating an index equivalent to the National Institute of Health Stroke Score (NIHSS) motor index. The system is developed by collecting data from 15 patients. We have successfully demonstrated an end-to-end stroke monitoring system reporting an accuracy of calculating stroke index of more than 80%, highest Cohen's overall agreement of 0.91 (with excellent κ coefficient of 0.76). A wireless accelerometer based 'hot stroke' monitoring system is developed to monitor the motor recovery in acute-stroke patients. It has been shown to monitor stroke patients continuously, which has not been possible so far with high reliability.

Higher Education Is Associated with a Lower Risk of Dementia after a Stroke or TIA. The Rotterdam Study.

PubMed

Mirza, Saira Saeed; Portegies, Marileen L P; Wolters, Frank J; Hofman, Albert; Koudstaal, Peter J; Tiemeier, Henning; Ikram, M Arfan

2016-01-01

Higher education is associated with a lower risk of dementia, possibly because of a higher tolerance to subclinical neurodegenerative pathology. Whether higher education also protects against dementia after clinical stroke or transient ischemic attack (TIA) remains unknown. Within the population-based Rotterdam Study, 12,561 participants free of stroke, TIA and dementia were followed for occurrence of stroke, TIA and dementia. Across the levels of education, associations of incident stroke or TIA with subsequent development of dementia and differences in cognitive decline following stroke or TIA were investigated. During 124,862 person-years, 1,463 persons suffered a stroke or TIA, 1,158 persons developed dementia, of whom 186 developed dementia after stroke or TIA. Risk of dementia after a stroke or TIA, compared to no stroke or TIA, was highest in the low education category (hazards ratio [HR] 1.46, 95% CI 1.18-1.81) followed by intermediate education category (HR 1.36, 95% CI 1.03-1.81). No significant association was observed in the high education category (HR 0.62, 95% CI 0.25-1.54). In gender stratified analyses, decrease in risk of dementia with increasing education was significant only in men. Higher education is associated with a lower risk of dementia after stroke or TIA, particularly in men, which might be explained by a higher cognitive reserve. © 2016 S. Karger AG, Basel.

RNA Expression Profiles from Blood for the Diagnosis of Stroke and its Causes

PubMed Central

Sharp, Frank R; Jickling, Glen C; Stamova, Boryana; Tian, Yingfang; Zhan, Xinhua; Ander, Bradley P; Cox, Christopher; Kuczynski, Beth; Liu, DaZhi

2013-01-01

A blood test to detect stroke and its causes would be particularly useful in babies, young children, and patients in intensive care units, and for emergencies when imaging is difficult to obtain or unavailable. Using whole genome microarrays, we first showed specific gene expression profiles in rats 24 hours after ischemic and hemorrhagic stroke, hypoxia, and hypoglycemia. These proof-of-principle studies revealed that groups of genes (called gene profiles) can distinguish ischemic stroke patients from controls 3 hours to 24 hours after the strokes. In addition, gene expression profiles have been developed that distinguish stroke due to large-vessel atherosclerosis from cardioembolic stroke. These profiles will be useful for predicting the causes of cryptogenic stroke. Our results in adults suggest similar diagnostic tools could be developed for children. PMID:21636778

Executive dysfunction post-stroke: an insight into the perspectives of physiotherapists.

PubMed

Hayes, Sara; Donnellan, Claire; Stokes, Emma

2015-01-01

To gain an understanding of physiotherapy practice in relation to executive dysfunction (ED) post-stroke. Three focus groups were conducted using semi-structured interview schedules to highlight how ED post-stroke was understood by 12 physiotherapists with greater than 1 year of experience working in the area of stroke care. The focus group data were analysed using qualitative data analysis. The themes extracted from the data on physiotherapists' self-reported knowledge of ED post-stroke were: physiotherapists' lack of knowledge of ED post-stroke; current physiotherapy practice regarding ED post-stroke; the negative impact of ED on physiotherapy rehabilitation post-stroke and the future learning needs of physiotherapists regarding ED post-stroke. Current results demonstrate that ED has negative implications for physiotherapy rehabilitation post-stroke. Although further interdisciplinary research is warranted, the present results suggest that physiotherapists should be aware of the presence of ED in people post-stroke and develop strategies to minimise the impact of ED on physiotherapy rehabilitation. Implications for Rehabilitation Physiotherapists report a lack of knowledge of ED post-stroke and a requirement for future learning and training regarding the optimal management of people with ED undergoing physiotherapy rehabilitation post-stroke. ED has negative implications for physiotherapy rehabilitation post-stroke and physiotherapists should be aware of the presence of ED in people post-stroke and develop strategies to minimise the impact of ED on physiotherapy rehabilitation.

Blood pressure as a therapeutic target in stroke.

PubMed

Armario, Pedro; de la Sierra, Alejandro

2009-01-01

Stroke, as a clinical manifestation of the cardiovascular diseases, is one of the leading causes of death and disability in both developed and developing countries. Hypertension is by far, the most important risk factor for stroke. Epidemiological data indicate that the risk of stroke increases with both systolic and diastolic blood pressure elevation, from levels of 115/75 mmHg. It is also evident that most adults worldwide have values above these limits, thus emphasizing the importance of blood pressure as a risk factor for stroke. Clinical trials of antihypertensive treatment, both in studies that have compared active drugs against placebo or in those comparing different types of drugs have clearly demonstrated a protective effect of blood pressure reduction in the prevention of stroke. The degree of protection is directly related to blood pressure reduction and, the lower the level, the better the prognosis. Although data on secondary stroke prevention are scarcer, studies also seem to indicate that lowering blood pressure with antihypertensive treatment protects against stroke recurrence. At the present moment there is still uncertainty on 2 different aspects regarding the relationship between antihypertensive treatment and stroke. First, the blood pressure management during acute stroke has not adequately investigated in clinical trials. Second, the possibility of a protective role of specific types of antihypertensive drugs beyond blood pressure reduction is a matter of debate. Independently of these unresolved issues, prevention of hypertension development by lifestyle changes and adequate treatment and control to the hypertensive population will be a very effective measure in reducing stroke incidence, stroke recurrence, and stroke mortality.

Development and Pilot Testing of 24/7 In-Ambulance Telemedicine for Acute Stroke: Prehospital Stroke Study at the Universitair Ziekenhuis Brussel-Project.

PubMed

Valenzuela Espinoza, Alexis; Van Hooff, Robbert-Jan; De Smedt, Ann; Moens, Maarten; Yperzeele, Laetitia; Nieboer, Koenraad; Hubloue, Ives; de Keyser, Jacques; Convents, Andre; Fernandez Tellez, Helio; Dupont, Alain; Putman, Koen; Brouns, Raf

2016-01-01

In-ambulance telemedicine is a recently developed and a promising approach to improve emergency care. We implemented the first ever 24/7 in-ambulance telemedicine service for acute stroke. We report on our experiences with the development and pilot testing of the Prehospital Stroke Study at the Universitair Ziekenhuis Brussel (PreSSUB) to facilitate a wider spread of the knowledge regarding this technique. Successful execution of the project involved the development and validation of a novel stroke scale, design and creation of specific hardware and software solutions, execution of field tests for mobile internet connectivity, design of new care processes and information flows, recurrent training of all professional caregivers involved in acute stroke management, extensive testing on healthy volunteers, organisation of a 24/7 teleconsultation service by trained stroke experts and 24/7 technical support, and resolution of several legal issues. In all, it took 41 months of research and development to confirm the safety, technical feasibility, reliability, and user acceptance of the PreSSUB approach. Stroke-specific key information can be collected safely and reliably before and during ambulance transportation and can adequately be communicated with the inhospital team awaiting the patient. This paper portrays the key steps required and the lessons learned for successful implementation of a 24/7 expert telemedicine service supporting patients with acute stroke during ambulance transportation to the hospital. © 2016 S. Karger AG, Basel.

Epigenetic regulation of inflammation in stroke

PubMed Central

Ng, Gavin Yong-Quan; Yun-An, Lim; Sobey, Christopher G.; Dheen, Thameem; Fann, David Yang-Wei; Arumugam, Thiruma V.

2018-01-01

Despite extensive research, treatments for clinical stroke are still limited only to the administration of tissue plasminogen activator and the recent introduction of mechanical thrombectomy, which can be used in only a limited proportion of patients due to time constraints. A plethora of inflammatory events occur during stroke, arising in part due to the body’s immune response to brain injury. Neuroinflammation contributes significantly to neuronal cell death and the development of functional impairment and death in stroke patients. Therefore, elucidating the molecular and cellular mechanisms underlying inflammatory damage following stroke injury will be essential for the development of useful therapies. Research findings increasingly point to the likelihood that epigenetic mechanisms play a role in the pathophysiology of stroke. Epigenetics involves the differential regulation of gene expression, including those involved in brain inflammation and remodelling after stroke. Hence, it is conceivable that epigenetic mechanisms may contribute to differential interindividual vulnerability and injury responses to cerebral ischaemia. In this review, we summarize recent findings on the emerging role of epigenetics in the regulation of neuroinflammation in stroke. We also discuss potential epigenetic targets that may be assessed for the development of stroke therapies. PMID:29774056

High Risk of Seizures and Epilepsy after Decompressive Hemicraniectomy for Malignant Middle Cerebral Artery Stroke
.

PubMed

Brondani, Rosane; Garcia de Almeida, Andrea; Abrahim Cherubini, Pedro; Mandelli Mota, Suelen; de Alencastro, Luiz Carlos; Antunes, Apio Cláudio Martins; Bianchin Muxfeldt, Marino

2017-01-01

Decompressive hemicraniectomy (DHC) is a life-saving procedure for treatment of large malignant middle cerebral artery (MCA) strokes. Post-stroke epilepsy is an additional burden for these patients, but its incidence and the risk factors for its development have been poorly investigated. To report the prevalence and risk factors for post-stroke seizures and post-stroke epilepsy after DHC for treatment of large malignant MCA strokes in a cohort of 36 patients. In a retrospective cohort study of 36 patients we report the timing and incidence of post-stroke epilepsy. We analyzed if age, sex, vascular risk factors, side of ischemia, reperfusion therapy, stroke etiology, extension of stroke, hemorrhagic transformation, ECASS scores, National Institutes of Health Stroke Scale (NIHSS) scores, or modified Rankin scores were risk factors for seizure or epilepsy after DHC for treatment of large MCA strokes. The mean patient follow-up time was 1,086 days (SD = 1,172). Out of 36 patients, 9 (25.0%) died before being discharged. After 1 year, a total of 11 patients (30.6%) had died, but 22 (61.1%) of them had a modified Rankin score ≤4. Thirteen patients (36.1%) developed seizures within the first week after stroke. Seizures occurred in 22 (61.1%) of 36 patients (95% CI = 45.17-77.03%). Out of 34 patients who survived the acute period, 19 (55.9%) developed epilepsy after MCA infarcts and DHC (95% CI = 39.21-72.59%). In this study, no significant differences were observed between the patients who developed seizures or epilepsy and those who remained free of seizures or epilepsy regarding age, sex, side of stroke, presence of the clinical risk factors studied, hemorrhagic transformation, time of craniectomy, and Rankin score after 1 year of stroke. The incidence of seizures and epilepsy after malignant MCA infarcts submitted to DHC might be very high. Seizure might occur precociously in patients who are not submitted to anticonvulsant prophylaxis. The large stroke volume and the large cortical ischemic area seem to be the main risk factors for seizure or epilepsy development in this subtype of stroke.
. © 2017 The Author(s)
. Published by S. Karger AG, Basel.

Singapore Tele-technology Aided Rehabilitation in Stroke (STARS) trial: protocol of a randomized clinical trial on tele-rehabilitation for stroke patients.

PubMed

Koh, Gerald Choon-Huat; Yen, Shih Cheng; Tay, Arthur; Cheong, Angela; Ng, Yee Sien; De Silva, Deidre Anne; Png, Carolina; Caves, Kevin; Koh, Karen; Kumar, Yogaprakash; Phan, Shi Wen; Tai, Bee Choo; Chen, Cynthia; Chew, Effie; Chao, Zhaojin; Chua, Chun En; Koh, Yen Sin; Hoenig, Helen

2015-09-05

Most acute stroke patients with disabilities do not receive recommended rehabilitation following discharge to the community. Functional and social barriers are common reasons for non-adherence to post-discharge rehabilitation. Home rehabilitation is an alternative to centre-based rehabilitation but is costlier. Tele-rehabilitation is a possible solution, allowing for remote supervision of rehabilitation and eliminating access barriers. The objective of the Singapore Tele-technology Aided Rehabilitation in Stroke (STARS) trial is to determine if a novel tele-rehabilitation intervention for the first three months after stroke admission improves functional recovery compared to usual care. This is a single blind (evaluator blinded), parallel, two-arm randomised controlled trial study design involving 100 recent stroke patients. The inclusion criteria are age ≥40 years, having caregiver support and recent stroke defined as stroke diagnosis within 4 weeks. Consenting participants will be randomized with varying block size of 4 or 6 assuming a 1:1 treatment allocation with the participating centre as the stratification factor. The baseline assessment will be done within 4 weeks of stroke onset, followed by follow-up assessments at 3 and 6 months. The tele-rehabilitation intervention lasts for 3 months and includes exercise 5-days-a-week using an iPad-based system that allows recording of daily exercise with video and sensor data and weekly video-conferencing with tele-therapists after data review. Those allocated to the control group will receive usual care. The primary outcome measure is improvement in life task's social activity participation at three months as measured by the disability component of the Jette Late Life Functional and Disability Instrument (LLFDI). Secondary outcome variables consist of gait speed (Timed 5-Meter Walk Test) and endurance (Two-Minute Walk test), performance of basic activities of daily living (Shah-modified Barthel Index), balance confidence (Activities-Specific Balance Confidence Scale), patient self-reported health-related quality-of-life [Euro-QOL (EQ-5D)], health service utilization (Singapore Stroke Study Health Service Utilization Form) and caregiver reported stress (Zarit Caregiver Burden Inventory). The goal of this trial is to provide evidence on the potential benefit and cost-effectiveness of this novel tele-rehabilitation programme which will guide health care decision-making and potentially improve performance of post-stroke community-based rehabilitation. This trial protocol was registered under ClinicalTrials.gov on 18 July 2013 as study title "The Singapore Tele-technology Aided Rehabilitation in Stroke (STARS) Study" (ID: The STARS Study, ClinicalTrials.gov Identifier: NCT01905917 ).

Blood Biomarkers for the Early Diagnosis of Stroke: The Stroke-Chip Study.

PubMed

Bustamante, Alejandro; López-Cancio, Elena; Pich, Sara; Penalba, Anna; Giralt, Dolors; García-Berrocoso, Teresa; Ferrer-Costa, Carles; Gasull, Teresa; Hernández-Pérez, María; Millan, Mónica; Rubiera, Marta; Cardona, Pedro; Cano, Luis; Quesada, Helena; Terceño, Mikel; Silva, Yolanda; Castellanos, Mar; Garces, Moisés; Reverté, Silvia; Ustrell, Xavier; Marés, Rafael; Baiges, Joan Josep; Serena, Joaquín; Rubio, Francisco; Salas, Eduardo; Dávalos, Antoni; Montaner, Joan

2017-09-01

Stroke diagnosis could be challenging in the acute phase. We aimed to develop a blood-based diagnostic tool to differentiate between real strokes and stroke mimics and between ischemic and hemorrhagic strokes in the hyperacute phase. The Stroke-Chip was a prospective, observational, multicenter study, conducted at 6 Stroke Centers in Catalonia. Consecutive patients with suspected stroke were enrolled within the first 6 hours after symptom onset, and blood samples were drawn immediately after admission. A 21-biomarker panel selected among previous results and from the literature was measured by immunoassays. Outcomes were differentiation between real strokes and stroke mimics and between ischemic and hemorrhagic strokes. Predictive models were developed by combining biomarkers and clinical variables in logistic regression models. Accuracy was evaluated with receiver operating characteristic curves. From August 2012 to December 2013, 1308 patients were included (71.9% ischemic, 14.8% stroke mimics, and 13.3% hemorrhagic). For stroke versus stroke mimics comparison, no biomarker resulted included in the logistic regression model, but it was only integrated by clinical variables, with a predictive accuracy of 80.8%. For ischemic versus hemorrhagic strokes comparison, NT-proBNP (N-Terminal Pro-B-Type Natriuretic Peptide) >4.9 (odds ratio, 2.40; 95% confidence interval, 1.55-3.71; P <0.0001) and endostatin >4.7 (odds ratio, 2.02; 95% confidence interval, 1.19-3.45; P =0.010), together with age, sex, blood pressure, stroke severity, atrial fibrillation, and hypertension, were included in the model. Predictive accuracy was 80.6%. The studied biomarkers were not sufficient for an accurate differential diagnosis of stroke in the hyperacute setting. Additional discovery of new biomarkers and improvement on laboratory techniques seem necessary for achieving a molecular diagnosis of stroke. © 2017 American Heart Association, Inc.

Does national expenditure on research and development influence stroke outcomes?

PubMed

Kim, Young Dae; Jung, Yo Han; Norrving, Bo; Ovbiagele, Bruce; Saposnik, Gustavo

2017-10-01

Background Expenditure on research and development is a macroeconomic indicator representative of national investment. International organizations use this indicator to compare international research and development activities. Aim We investigated whether differences in expenditures on research and development at the country level may influence the incidence of stroke and stroke mortality. Methods We compared stroke metrics with absolute amount of gross domestic expenditure on R&D (GERD) per-capita adjusted for purchasing power parity (aGERD) and relative amount of GERD as percent of gross domestic product (rGERD). Sources included official data from the UNESCO, the World Health Organization, the World Bank, and population-based studies. We used correlation analysis and multivariable linear regression modeling. Results Overall, data on stroke mortality rate and GERD were available from 66 countries for two periods (2002 and 2008). Age-standardized stroke mortality rate was associated with aGERD (r = -0.708 in 2002 and r = -0.730 in 2008) or rGERD (r = -0.545 in 2002 and r = -0.657 in 2008) (all p < 0.001). Multivariable analysis showed a lower aGERD and rGERD were independently and inversely associated with higher stroke mortality (all p < 0.05). The estimated prevalence of hypertension, diabetes, or obesity was higher in countries with lower aGERD. The analysis of 27 population-based studies showed consistent inverse associations between aGERD or rGERD and incident risk of stroke and 30-day case fatality. Conclusions There is higher stroke mortality among countries with lower expenditures in research and development. While this study does not prove causality, it suggests a potential area to focus efforts to improve global stroke outcomes.

Increased risk of brain cancer incidence in stroke patients: a clinical case series, population-based and longitudinal follow-up study.

PubMed

Chen, Chih-Wei; Cheng, Tain-Junn; Ho, Chung-Han; Wang, Jhi-Joung; Weng, Shih-Feng; Hou, Ya-Chin; Cheng, Hung-Chi; Chio, Chung-Ching; Shan, Yan-Shen; Chang, Wen-Tsan

2017-12-12

Stroke and brain cancer are two distinct diseases. However, the relationship between both diseases has rarely been examined. This study investigated the longitudinal risk for developing brain cancer in stroke patients. To study this, we first reviewed the malignant gliomas previously with or without stroke using brain magnetic resonance imaging (MRI) images and the past histories. Two ischemic stroke patients before the malignant glioma were identified and belonged to the glioblastoma mutiforme (GBM). Particularly, both GBM specimens displayed strong hypoxia-inducible factor 1α (HIF-1α) expression in immunohistochemical (IHC) staining. To elucidate the significance of this relationship, we then used a nationwide population-based cohort in Taiwan to investigate the risk for the incidence of brain cancer in patients previously with or without stroke. The incidence of all tumors in the stroke group was lower than that in the control group with an adjusted hazard ratio (HR) of 0.79 (95% confidence interval [CI]: 0.74-0.84) in both gender and age older than 60 years. But the stroke patients had higher risk of developing only brain cancer with an adjusted HR of 3.09 (95% CI: 1.80-5.30), and otherwise had lower risk of developing head and neck, digestive, respiratory, bone and skin, as well as other tumors, all with p<0.05. After stratification by gender and age, the female and aged 40-60 year old stroke patients had higher risk of developing brain cancer with an adjusted HR of 7.41 (95% CI: 3.30-16.64) and 16.34 (95% CI: 4.45-62.13), respectively, both with p<0.05. Patients with stroke, in particular female and age 40-60 years old, have an increased risk for developing brain cancer.

A Reduced Order Model of the Linearized Incompressible Navier-Strokes Equations for the Sensor/Actuator Placement Problem

NASA Technical Reports Server (NTRS)

Allan, Brian G.

2000-01-01

A reduced order modeling approach of the Navier-Stokes equations is presented for the design of a distributed optimal feedback kernel. This approach is based oil a Krylov subspace method where significant modes of the flow are captured in the model This model is then used in all optimal feedback control design where sensing and actuation is performed oil tile entire flow field. This control design approach yields all optimal feedback kernel which provides insight into the placement of sensors and actuators in the flow field. As all evaluation of this approach, a two-dimensional shear layer and driven cavity flow are investigated.

Development and Validation of a Bilingual Stroke Preparedness Assessment Instrument.

PubMed

Skolarus, Lesli E; Mazor, Kathleen M; Sánchez, Brisa N; Dome, Mackenzie; Biller, José; Morgenstern, Lewis B

2017-04-01

Stroke preparedness interventions are limited by the lack of psychometrically sound intermediate end points. We sought to develop and assess the reliability and validity of the video-Stroke Action Test (video-STAT) an English and a Spanish video-based test to assess people's ability to recognize and react to stroke signs. Video-STAT development and testing was divided into 4 phases: (1) video development and community-generated response options, (2) pilot testing in community health centers, (3) administration in a national sample, bilingual sample, and neurologist sample, and (4) administration before and after a stroke preparedness intervention. The final version of the video-STAT included 8 videos: 4 acute stroke/emergency, 2 prior stroke/nonemergency, 1 nonstroke/emergency, and 1 nonstroke/nonemergency. Acute stroke recognition and action response were queried after each vignette. Video-STAT scoring was based on the acute stroke vignettes only (score range 0-12 best). The national sample consisted of 598 participants, 438 who took the video-STAT in English and 160 who took the video-STAT in Spanish. There was adequate internal consistency (Cronbach α=0.72). The average video-STAT score was 5.6 (SD=3.6), whereas the average neurologist score was 11.4 (SD=1.3). There was no difference in video-STAT scores between the 116 bilingual video-STAT participants who took the video-STAT in English or Spanish. Compared with baseline scores, the video-STAT scores increased after a stroke preparedness intervention (6.2 versus 8.9, P <0.01) among a sample of 101 black adults and youth. The video-STAT yields reliable scores that seem to be valid measures of stroke preparedness. © 2017 American Heart Association, Inc.

γδ T cells as early sensors of tissue damage and mediators of secondary neurodegeneration

PubMed Central

Gelderblom, Mathias; Arunachalam, Priyadharshini; Magnus, Tim

2014-01-01

Spontaneous or medically induced reperfusion occurs in up to 70% of patients within 24 h after cerebral ischemia. Reperfusion of ischemic brain tissue can augment the inflammatory response that causes additional injury. Recently, T cells have been shown to be an essential part of the post-ischemic tissue damage, and especially IL-17 secreting T cells have been implicated in the pathogenesis of a variety of inflammatory reactions in the brain. After stroke, it seems that the innate γδ T cells are the main IL-17 producing cells and that the γδ T cell activation constitutes an early and mainly damaging immune response in stroke. Effector mechanism of γδ T cell derived IL-17 in the ischemic brain include the induction of metalloproteinases, proinflammatory cytokines and neutrophil attracting chemokines, leading to a further amplification of the detrimental inflammatory response. In this review, we will give an overview on the concepts of γδ T cells and IL-17 in stroke pathophysiology and on their potential importance for human disease conditions. PMID:25414640

Effect of Statin Intensity on the Risk of Epilepsy After Ischaemic Stroke: Real-World Evidence from Population-Based Health Claims.

PubMed

Lin, Fang-Ju; Lin, Hung-Wei; Ho, Yunn-Fang

2018-04-01

Statins possess neuroprotective effects. However, real-world evidence supporting their utility in post-stroke epilepsy (PSE) prevention is limited. The association between statin use, including timing of prescribing (pre-stroke vs post-stroke), type (lipophilicity, intensity of therapy) and dose intensity, and risk of developing PSE were investigated by studying Taiwanese health claims (2003-2013). Patients with new-onset ischaemic stroke were identified. The main outcome was a diagnosis of epilepsy after ischaemic stroke. According to pre-stroke statin use, groups of current users, former users, and non-users were compared using ANOVA. An extended Cox regression model was utilized to estimate the hazard ratio (HR) of PSE, with post-stroke statin use and certain comedications as time-dependent variables. Serial sensitivity analyses were performed to ensure study robustness. Of the 20,858 ischaemic stroke patients, 954 (4.6%) developed PSE. Post-stroke statin use (adjusted HR (aHR) 0.55; 95% confidence interval 0.46-0.67, p < 0.001), but not pre-stroke statin use was associated with a significantly reduced risk of developing PSE. A dose-response correlation was also observed between PSE risk reduction and quartiles of the statin cumulative defined daily dose (cDDD) (aHR 0.84, 0.67, 0.53, and 0.50 for the lowest, second, third, and highest quartiles of cDDD, respectively). Risk predictors and protectors against PSE were also characterized. The post-stroke use of statins after ischaemic stroke was associated with PSE risk reduction in a cDDD-dependent manner. Further clinical studies on the potential applications of statins for PSE prophylaxis, particularly among at-risk patients, are warranted.

Retinal vein occlusion and the risk of stroke development: a 9-year nationwide population-based study.

PubMed

Rim, Tyler Hyungtaek; Kim, Dong Wook; Han, John Seungsoo; Chung, Eun Jee

2015-06-01

To evaluate the risk of stroke development after retinal vein occlusion (RVO). Nationwide, population-based 9-year longitudinal study. National registry data were collected from the Korean National Health Insurance Research Database, comprising 1 025 340 (∼2.2%) random subjects who were selected from 46 605 433 Korean residents in 2002. Patients diagnosed with RVO or stroke in 2002 were excluded. The RVO group was composed of patients with an initial diagnosis of central or branch RVO between January 2003 and December 2005 (n = 344 in 2003, 375 in 2004, and 312 in 2005). The comparison group was composed of randomly selected patients (5 per patient with RVO; n = 1696 in 2003, 1854 in 2004, and 1524 in 2005) who were matched to the RVO group according to age, sex, residential area, household income, and year of RVO diagnosis. Each sampled patient was tracked until 2010. Cox proportional hazard regressions were used to calculate the overall survival rate for stroke development after adjusting for potential confounders, including hypertension, diabetes mellitus, and chronic kidney disease. Retinal vein occlusion and ischemic or hemorrhagic stroke based on the International Classification of Disease codes. Stroke developed in 16.8% of the RVO group and in 10.7% of the comparison group. Retinal vein occlusion was associated with an increased risk of stroke development (hazard ratio [HR], 1.48; 95% confidence interval [CI], 1.24-1.76). Hypertension, diabetes mellitus, and chronic kidney disease also increased the risk of stroke development. In addition, RVO increased the risk of both ischemic stroke (HR, 1.51; 95% CI, 1.24-1.84) and hemorrhagic stroke (HR, 1.30; 95% CI, 0.83-2.05), although this result was not significant for hemorrhagic stroke. In terms of age, the effect size of the HR was largest among younger adults, aged <50 years (HR, 2.69), compared with middle-aged adults, aged 50 to 69 years (HR, 1.33), and older adults, aged ≥70 years (HR, 1.46). Retinal vein occlusion was significantly associated with stroke development after adjusting for potential confounders. These findings are limited by uncontrolled confounding and need to be replicated by other observational studies. Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Acute kidney injury and edaravone in acute ischemic stroke: the Fukuoka Stroke Registry.

PubMed

Kamouchi, Masahiro; Sakai, Hironori; Kiyohara, Yutaka; Minematsu, Kazuo; Hayashi, Kunihiko; Kitazono, Takanari

2013-11-01

A free radical scavenger, edaravone, which has been used for the treatment of ischemic stroke, was reported to cause acute kidney injury (AKI) as a fatal adverse event. The aim of the present study was to clarify whether edaravone is associated with AKI in patients with acute ischemic stroke. From the Fukuoka Stroke Registry database, 5689 consecutive patients with acute ischemic stroke who were hospitalized within 24 hours of the onset of symptoms were included in this study. A logistic regression analysis for the Fukuoka Stroke Registry cohort was done to identify the predictors for AKI. A propensity score-matched nested case-control study was also performed to elucidate any association between AKI and edaravone. Acute kidney injury occurred in 128 of 5689 patients (2.2%) with acute ischemic stroke. A multivariate analysis revealed that the stroke subtype, the basal serum creatinine level, and the presence of infectious complications on admission were each predictors of developing AKI. In contrast, a free radical scavenger, edaravone, reduced the risk of developing AKI (multivariate-adjusted odds ratio [OR] .45, 95% confidence interval [CI] .30-.67). Propensity score-matched case-control study confirmed that edaravone use was negatively associated with AKI (propensity score-adjusted OR .46, 95% CI .29-.74). Although AKI has a significant impact on the clinical outcome of hospital inpatients, edaravone has a protective effect against the development of AKI in patients with acute ischemic stroke. Copyright © 2013 National Stroke Association. Published by Elsevier Inc. All rights reserved.

A simple prediction score for developing a hospital-acquired infection after acute ischemic stroke.

PubMed

Friedant, Adam J; Gouse, Brittany M; Boehme, Amelia K; Siegler, James E; Albright, Karen C; Monlezun, Dominique J; George, Alexander J; Beasley, Timothy Mark; Martin-Schild, Sheryl

2015-03-01

Hospital-acquired infections (HAIs) are a major cause of morbidity and mortality in acute ischemic stroke patients. Although prior scoring systems have been developed to predict pneumonia in ischemic stroke patients, these scores were not designed to predict other infections. We sought to develop a simple scoring system for any HAI. Patients admitted to our stroke center (July 2008-June 2012) were retrospectively assessed. Patients were excluded if they had an in-hospital stroke, unknown time from symptom onset, or delay from symptom onset to hospital arrival greater than 48 hours. Infections were diagnosed via clinical, laboratory, and imaging modalities using standard definitions. A scoring system was created to predict infections based on baseline patient characteristics. Of 568 patients, 84 (14.8%) developed an infection during their stays. Patients who developed infection were older (73 versus 64, P < .0001), more frequently diabetic (43.9% versus 29.1%, P = .0077), and had more severe strokes on admission (National Institutes of Health Stroke Scale [NIHSS] score 12 versus 5, P < .0001). Ranging from 0 to 7, the overall infection score consists of age 70 years or more (1 point), history of diabetes (1 point), and NIHSS score (0-4 conferred 0 points, 5-15 conferred 3 points, >15 conferred 5 points). Patients with an infection score of 4 or more were at 5 times greater odds of developing an infection (odds ratio, 5.67; 95% confidence interval, 3.28-9.81; P < .0001). In our sample, clinical, laboratory, and imaging information available at admission identified patients at risk for infections during their acute hospitalizations. If validated in other populations, this score could assist providers in predicting infections after ischemic stroke. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Functional status of acute stroke patients in University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia.

PubMed

Rameezan, B A R; Zaliha, O

2005-12-01

Stroke is a leading cause of death and disability in most developed countries and developing nations. Majority of the stroke survivors are left with significant physical and cognitive impairments. In addition to the improved acute stroke care, they often benefit from rehabilitation in improving their function. This was the first study done to document function for post stroke patients in Malaysia. It was prospective study conducted to document functional status of acute stroke patients upon admission, discharge and at 3 months post stroke. Assessment of functional status for these patients are based on their activities of daily living and ambulation i.e. self-care, sphincter control, mobility, locomotion, communication and social cognition. It is also aimed to describe their demographic and clinical characteristics. Correlation of functional status at 3 months post stroke with the initial severity of stroke was also explored. A total of fifty-one patients with acute stroke in University Malaya Medical Centre (UMMC) were recruited. The patient's age ranged from 38 to 83 years with a mean of 60.2 years. Thirty-six patients (71%) were first stroke sufferers and fifteen patients (29%) had recurrent stroke. At discharge from acute stay, 13% of patients were able to ambulate with aids and 87% needed assistance for ambulation in varying degrees. Eighty-two percent of patients showed improvement in overall function (both motor and cognition) at 3 months post stroke. Sixty percent of patients were independent in ambulation and 40% required assistance. Significant correlation was seen between the initial severity of stroke and functional status at 3 months post stroke. Functional status of patients with stroke has improved at 3 months post stroke. A comprehensive rehabilitation medicine programme should be incorporated into management of stroke patients to expedite functional recovery and improve patient's independence.

[Elements of system semiotics of the brain and head with cranial vessels of patients with stroke and with risk of stroke development].

PubMed

Makomela, N M

2007-01-01

By means of a multispiral computer and magnetic resonance tomography 211 patients with an ischemic stroke, 109 patients with hemorrhagic stroke, 41 patients with an arterial hypertensia, 43 patients with aneurism, 58 patients with discirculation encephalopathy, 125 patients with ischemic illness of heart, practically healthy 62 have been observed. The author found high frequency of pathological deformations of carotid and vertebral arteries of not closed arterial circle, calcification of the pineal body and vascular plexus of lateral ventricles. cysts of maxillary sinuses of patients with stroke in comparison with patients at risk of the development of stroke and practically healthy subjects.

Motor recovery monitoring using acceleration measurements in post acute stroke patients

PubMed Central

2013-01-01

Background Stroke is one of the major causes of morbidity and mortality. Its recovery and treatment depends on close clinical monitoring by a clinician especially during the first few hours after the onset of stroke. Patients who do not exhibit early motor recovery post thrombolysis may benefit from more aggressive treatment. Method A novel approach for monitoring stroke during the first few hours after the onset of stroke using a wireless accelerometer based motor activity monitoring system is developed. It monitors the motor activity by measuring the acceleration of the arms in three axes. In the presented proof of concept study, the measured acceleration data is transferred wirelessly using iMote2 platform to the base station that is equipped with an online algorithm capable of calculating an index equivalent to the National Institute of Health Stroke Score (NIHSS) motor index. The system is developed by collecting data from 15 patients. Results We have successfully demonstrated an end-to-end stroke monitoring system reporting an accuracy of calculating stroke index of more than 80%, highest Cohen’s overall agreement of 0.91 (with excellent κ coefficient of 0.76). Conclusion A wireless accelerometer based ‘hot stroke’ monitoring system is developed to monitor the motor recovery in acute-stroke patients. It has been shown to monitor stroke patients continuously, which has not been possible so far with high reliability. PMID:23590690

Stroke rehabilitation

PubMed Central

Bindawas, Saad M.; Vennu, Vishal S.

2016-01-01

Stroke is a major cause of death and other complications worldwide. In Saudi Arabia, stroke has become an emerging health issue leading to disability and death. However, stroke care including rehabilitation services, in Saudi Arabia lags behind developed countries. Stroke rehabilitation is an essential recovery option after stroke and should start as early as possible to avoid potential complications. The growing evidence on stroke rehabilitation effectiveness in different health care settings and outcome measures used widely are reviewed in this call to action paper. PMID:27744457

A strategic plan to accelerate development of acute stroke treatments.

PubMed

Marler, John R

2012-09-01

In order to reenergize acute stroke research and accelerate the development of new treatments, we need to transform the usual design and conduct of clinical trials to test for small but significant improvements in effectiveness, and treat patients as soon as possible after stroke onset when treatment effects are most detectable. This requires trials that include thousands of acute stroke patients. A plan to make these trials possible is proposed. There are four components: (1) free access to the electronic medical record; (2) a large stroke emergency network and clinical trial coordinating center connected in real time to hundreds of emergency departments; (3) a clinical trial technology development center; and (4) strategic leadership to raise funds, motivate clinicians to participate, and interact with politicians, insurers, legislators, and other national and international organizations working to advance the quality of stroke care. © 2012 New York Academy of Sciences.

A scoring system for ascertainment of incident stroke; the Risk Index Score (RISc).

PubMed

Kass-Hout, T A; Moyé, L A; Smith, M A; Morgenstern, L B

2006-01-01

The main objective of this study was to develop and validate a computer-based statistical algorithm that could be translated into a simple scoring system in order to ascertain incident stroke cases using hospital admission medical records data. The Risk Index Score (RISc) algorithm was developed using data collected prospectively by the Brain Attack Surveillance in Corpus Christi (BASIC) project, 2000. The validity of RISc was evaluated by estimating the concordance of scoring system stroke ascertainment to stroke ascertainment by physician and/or abstractor review of hospital admission records. RISc was developed on 1718 randomly selected patients (training set) and then statistically validated on an independent sample of 858 patients (validation set). A multivariable logistic model was used to develop RISc and subsequently evaluated by goodness-of-fit and receiver operating characteristic (ROC) analyses. The higher the value of RISc, the higher the patient's risk of potential stroke. The study showed RISc was well calibrated and discriminated those who had potential stroke from those that did not on initial screening. In this study we developed and validated a rapid, easy, efficient, and accurate method to ascertain incident stroke cases from routine hospital admission records for epidemiologic investigations. Validation of this scoring system was achieved statistically; however, clinical validation in a community hospital setting is warranted.

Incorporating Stroke Severity Into Hospital Measures of 30-Day Mortality After Ischemic Stroke Hospitalization.

PubMed

Schwartz, Jennifer; Wang, Yongfei; Qin, Li; Schwamm, Lee H; Fonarow, Gregg C; Cormier, Nicole; Dorsey, Karen; McNamara, Robert L; Suter, Lisa G; Krumholz, Harlan M; Bernheim, Susannah M

2017-11-01

The Centers for Medicare & Medicaid Services publicly reports a hospital-level stroke mortality measure that lacks stroke severity risk adjustment. Our objective was to describe novel measures of stroke mortality suitable for public reporting that incorporate stroke severity into risk adjustment. We linked data from the American Heart Association/American Stroke Association Get With The Guidelines-Stroke registry with Medicare fee-for-service claims data to develop the measures. We used logistic regression for variable selection in risk model development. We developed 3 risk-standardized mortality models for patients with acute ischemic stroke, all of which include the National Institutes of Health Stroke Scale score: one that includes other risk variables derived only from claims data (claims model); one that includes other risk variables derived from claims and clinical variables that could be obtained from electronic health record data (hybrid model); and one that includes other risk variables that could be derived only from electronic health record data (electronic health record model). The cohort used to develop and validate the risk models consisted of 188 975 hospital admissions at 1511 hospitals. The claims, hybrid, and electronic health record risk models included 20, 21, and 9 risk-adjustment variables, respectively; the C statistics were 0.81, 0.82, and 0.79, respectively (as compared with the current publicly reported model C statistic of 0.75); the risk-standardized mortality rates ranged from 10.7% to 19.0%, 10.7% to 19.1%, and 10.8% to 20.3%, respectively; the median risk-standardized mortality rate was 14.5% for all measures; and the odds of mortality for a high-mortality hospital (+1 SD) were 1.51, 1.52, and 1.52 times those for a low-mortality hospital (-1 SD), respectively. We developed 3 quality measures that demonstrate better discrimination than the Centers for Medicare & Medicaid Services' existing stroke mortality measure, adjust for stroke severity, and could be implemented in a variety of settings. © 2017 American Heart Association, Inc.

Recognizing upper limb movements with wrist worn inertial sensors using k-means clustering classification.

PubMed

Biswas, Dwaipayan; Cranny, Andy; Gupta, Nayaab; Maharatna, Koushik; Achner, Josy; Klemke, Jasmin; Jöbges, Michael; Ortmann, Steffen

2015-04-01

In this paper we present a methodology for recognizing three fundamental movements of the human forearm (extension, flexion and rotation) using pattern recognition applied to the data from a single wrist-worn, inertial sensor. We propose that this technique could be used as a clinical tool to assess rehabilitation progress in neurodegenerative pathologies such as stroke or cerebral palsy by tracking the number of times a patient performs specific arm movements (e.g. prescribed exercises) with their paretic arm throughout the day. We demonstrate this with healthy subjects and stroke patients in a simple proof of concept study in which these arm movements are detected during an archetypal activity of daily-living (ADL) - 'making-a-cup-of-tea'. Data is collected from a tri-axial accelerometer and a tri-axial gyroscope located proximal to the wrist. In a training phase, movements are initially performed in a controlled environment which are represented by a ranked set of 30 time-domain features. Using a sequential forward selection technique, for each set of feature combinations three clusters are formed using k-means clustering followed by 10 runs of 10-fold cross validation on the training data to determine the best feature combinations. For the testing phase, movements performed during the ADL are associated with each cluster label using a minimum distance classifier in a multi-dimensional feature space, comprised of the best ranked features, using Euclidean or Mahalanobis distance as the metric. Experiments were performed with four healthy subjects and four stroke survivors and our results show that the proposed methodology can detect the three movements performed during the ADL with an overall average accuracy of 88% using the accelerometer data and 83% using the gyroscope data across all healthy subjects and arm movement types. The average accuracy across all stroke survivors was 70% using accelerometer data and 66% using gyroscope data. We also use a Linear Discriminant Analysis (LDA) classifier and a Support Vector Machine (SVM) classifier in association with the same set of features to detect the three arm movements and compare the results to demonstrate the effectiveness of our proposed methodology. Copyright © 2014 Elsevier B.V. All rights reserved.

Assessing Gait Impairments Based on Auto-Encoded Patterns of Mahalanobis Distances from Consecutive Steps.

PubMed

Muñoz-Organero, Mario; Davies, Richard; Mawson, Sue

2017-01-01

Insole pressure sensors capture the force distribution patterns during the stance phase while walking. By comparing patterns obtained from healthy individuals to patients suffering different medical conditions based on a given similarity measure, automatic impairment indexes can be computed in order to help in applications such as rehabilitation. This paper uses the data sensed from insole pressure sensors for a group of healthy controls to train an auto-encoder using patterns of stochastic distances in series of consecutive steps while walking at normal speeds. Two experiment groups are compared to the healthy control group: a group of patients suffering knee pain and a group of post-stroke survivors. The Mahalanobis distance is computed for every single step by each participant compared to the entire dataset sensed from healthy controls. The computed distances for consecutive steps are fed into the previously trained autoencoder and the average error is used to assess how close the walking segment is to the autogenerated model from healthy controls. The results show that automatic distortion indexes can be used to assess each participant as compared to normal patterns computed from healthy controls. The stochastic distances observed for the group of stroke survivors are bigger than those for the people with knee pain.

Two decades of nation-wide community-based stroke support - The Singapore National Stroke Association.

PubMed

Venketasubramanian, Narayanaswamy; Yin, Ann; Lee, Lay B; De Silva, Deidre A

2017-04-01

The Singapore National Stroke Association, registered in 1996, offers support and information to stroke survivors and caregivers, and aims to raise public stroke awareness. In the last 20 years, we have developed programs to equip stroke survivors and caregivers with knowledge, life skills, comfort, and opportunities for socialization and reintegration. We have on-going public education and advocacy initiatives. Obtaining funding, member recruitment, volunteer retention, and leadership renewal are on-going challenges. Singapore National Stroke Association will continue to strive for the betterment of stroke survivors, their caregivers, and the public.

Classification of Small Negative Lightning Reports at the KSC-ER

NASA Technical Reports Server (NTRS)

Ward, Jennifer G.; Cummins, Kenneth L.; Krider, Philip

2008-01-01

The NASA Kennedy Space Center (KSC) and Air Force Eastern Range (ER) operate an extensive suite of lightning sensors because Florida experiences the highest area density of ground strikes in the United States, with area densities approaching 16 fl/sq km/yr when accumulated in 10x10 km (100 sq km) grids. The KSC-ER use data derived from two cloud-to-ground (CG) lightning detection networks, the "Cloud-to-Ground Lightning Surveillance System" (CGLSS) and the U.S. National Lightning Detection Network (TradeMark) (NLDN) plus a 3-dimensional lightning mapping system, the Lightning Detection and Ranging (LDAR) system, to provide warnings for ground operations and to insure mission safety during space launches. For operational applications at the KSC-ER it is important to understand the performance of each lightning detection system in considerable detail. In this work we examine a specific subset of the CGLSS stroke reports that have low values of the negative inferred peak current, Ip, i.e. values between 0 and -7 kA, and were thought to produce a new ground contact (NGC). When possible, the NLDN and LDAR systems were used to validate the CGLSS classification and to determine how many of these reported strokes were first strokes, subsequent strokes in a pre-existing channel (PEC), or cloud pulses that the CGLSS misclassified as CG strokes. It is scientifically important to determine the smallest current that can reach the ground either in the form of a first stroke or by way of a subsequent stroke that creates a new ground contact. In Biagi et al (2007), 52 low amplitude, negative return strokes ([Ip] < or = 10 kA) were evaluated in southern Arizona, northern Texas, and southern Oklahoma. The authors found that 50-87% of the small NLDN reports could be classified as CG (either first or subsequent strokes) on the basis of video and waveform recordings. Low amplitude return strokes are interesting because they are usually difficult to detect, and they are thought to bypass conventional lightning protection that relies on a sufficient attractive radius to prevent "shielding failure" (Golde, 1977). They also have larger location errors compared to the larger current events. In this study, we use the estimated peak current provided by the CGLSS and the results of our classification to determine the minimum Ip for each category of CG stroke and its probability of occurrence. Where possible, these results are compared to the findings in the literature.

Poverty and stroke in India: a time to act.

PubMed

Pandian, Jeyaraj D; Srikanth, Velandai; Read, Stephen J; Thrift, Amanda G

2007-11-01

In developed countries, the predominant health problems are those lifestyle-related illnesses associated with increased wealth. In contrast, diseases occurring in developing countries can largely be attributed to poverty, poor healthcare infrastructure, and limited access to care. However, many developing countries such as India have undergone economic and demographic growth in recent years resulting in a transition from diseases caused by poverty toward chronic, noncommunicable, lifestyle-related diseases. Despite this recent rapid economic growth, a large proportion of the Indian population lives in poverty. Although risk factors for stroke in urban Indian populations are similar to developed nations, it is likely that they may be quite different among those afflicted by poverty. Furthermore, treatment options for stroke are fewer in developing countries like India. Well-organized stroke services and emergency transport services are lacking, many treatments are unaffordable, and sociocultural factors may influence access to medical care for many stroke victims. Most stroke centers are currently in the private sector and establishing such centers in the public sector will require enormous capital investment. Given the limited resources available for hospital treatments, it would be logical to place a greater emphasis on effective populationwide interventions to control or reduce exposure to leading stroke risk factors. There also needs to be a concerted effort to ensure access to stroke care programs that are tailored to suit Indian communities and are accessible to the large majority of the population, namely the poor.

NEUROIMAGING CHARACTERISTICS AND POST-STROKE FATIGUE WITHIN THE FIRST 6 MONTHS AFTER ISCHEMIC STROKES.

PubMed

Delva, M; Delva, I

2017-10-01

Aim - identify neuroimaging characteristics associated with different post-stroke fatigue (PSF) domains within first 6 months after ischemic strokes. There were enrolled in the study 107 patients with acute ischemic strokes. General PSF and certain PSF domains (global, physical, mental, motivational, activity-related) were measured by multidimensional fatigue inventory-20 (MFI-20) scale at hospital stay, in 1, 3 and 6 months after stroke occurrence. Brain MRI studies included cerebral infarct localization, planimetric measurements of infarct volumes, measurement of brain atrophy indexes (bifrontal, bicaudate, cortical atrophy indexes, width of third ventricle) and evaluation of leukoaraiosis severity, according to Fazekas scale. In univariate logistic regression analysis infarcts volumes as well as brain atrophy indexes were not significantly associated with risk of any PSF domain at any time points within first 6 months after ischemic strokes. On the other hand, it had been found reliable associations between subcortical infarcts and increased risk of PSF domains which are related just to physical activity (physical PSF, activity-related PSF) in 1 month after stroke onset and later, as well as reliable associations between infratentorial infarcts and risk of global PSF domain in 3 months after stroke and later. Moreover, it have been revealed significant direct associations between severity of white matter lesions and risk of mental PSF in 3 months after stroke onset and later. Subcortical infarcts may be risk factors for development of physical PSF domain, infratentorial infarcts - risk factors for development of global PSF domain, leukoaraiosis extension - risk factor for development of mental PSF domain but not early than 1 month after stroke occurrence.

Walking during body-weight-supported treadmill training and acute responses to varying walking speed and body-weight support in ambulatory patients post-stroke.

PubMed

Aaslund, Mona Kristin; Helbostad, Jorunn Lægdheim; Moe-Nilssen, Rolf

2013-05-01

Rehabilitating walking in ambulatory patients post-stroke, with training that is safe, task-specific, intensive, and of sufficient duration, can be challenging. Some challenges can be met by using body-weight-supported treadmill training (BWSTT). However, it is not known to what degree walking characteristics are similar during BWSTT and overground walking. In addition, important questions regarding the training protocol of BWSTT remain unanswered, such as how proportion of body-weight support (BWS) and walking speed affect walking characteristics during training. The objective was therefore to investigate if and how kinematic walking characteristics are different between overground walking and treadmill walking with BWS in ambulatory patients post-stroke, and the acute response of altering walking speed and percent BWS during treadmill walking with BWS. A cross-sectional repeated-measures design was used. Ambulating patients post-stroke walked in slow, preferred, and fast walking speed overground and at comparable speeds on the treadmill with 20% and 40% BWS. Kinematic walking characteristics were obtained using a kinematic sensor attached over the lower back. Forty-four patients completed the protocol. Kinematic walking characteristics were similar during treadmill walking with BWS, compared to walking overground. During treadmill walking, choice of walking speed had greater impact on kinematic walking characteristics than proportion of BWS. Faster walking speeds tended to affect the kinematic walking characteristics positively. This implies that in order to train safely and with sufficient intensity and duration, therapists may choose to include BWSTT in walking rehabilitation also for ambulatory patients post-stroke without aggravating gait pattern during training.

WWLLN lightning and satellite microwave radiometrics at 37 to 183 GHz: Thunderstorms in the broad tropics

NASA Astrophysics Data System (ADS)

Solorzano, N. N.; Thomas, J. N.; Hutchins, M. L.; Holzworth, R. H.

2016-10-01

We investigate lightning strokes and deep convection through the examination of cloud-to-ground (CG) lightning from the World Wide Lightning Location Network (WWLLN) and passive microwave radiometer data. Microwave channels at 37 to 183.3 GHz are provided by the Tropical Rainfall Measuring Mission satellite (TRMM) Microwave Imager (TMI) and the Special Sensor Microwave Imager/Sounder (SSMIS) on the Defense Meteorological Satellite Program (DMSP) satellite F16. The present study compares WWLLN stroke rates and minimum radiometer brightness temperatures (Tbs) for two Northern Hemisphere and Southern Hemisphere summers (2009-2011) in the broad tropics (35°S to 35°N). To identify deep convection, we use lightning data and Tbs derived from all channels and differences in the Tbs (ΔTbs) of the three water vapor channels near 183.3 GHz. We find that stroke probabilities increase with increasing Tb depressions for all frequencies examined. Moreover, we apply methods that use the 183.3 GHz channels to pinpoint deep convection associated with lightning. High lightning stroke probabilities are found over land regions for both intense and relatively weak convective systems, although the TMI 85 GHz results should be used with caution as they are affected by a 7 km gap between the conical scans. Over the ocean, lightning is associated mostly with larger Tb depressions. Generally, our results support the noninductive thundercloud charging mechanism but do not rule out the inductive mechanism during the mature stages of storms. Lastly, we present a case study in which lightning stroke rates are used to reconstruct microwave radiometer Tbs.

Stroke outcomes measures must be appropriately risk adjusted to ensure quality care of patients: a presidential advisory from the American Heart Association/American Stroke Association.

PubMed

Fonarow, Gregg C; Alberts, Mark J; Broderick, Joseph P; Jauch, Edward C; Kleindorfer, Dawn O; Saver, Jeffrey L; Solis, Penelope; Suter, Robert; Schwamm, Lee H

2014-05-01

Because stroke is among the leading causes of death, disability, hospitalizations, and healthcare expenditures in the United States, there is interest in reporting outcomes for patients hospitalized with acute ischemic stroke. The American Heart Association/American Stroke Association, as part of its commitment to promote high-quality, evidence-based care for cardiovascular and stroke patients, fully supports the development of properly risk-adjusted outcome measures for stroke. To accurately assess and report hospital-level outcomes, adequate risk adjustment for case mix is essential. During the development of the Centers for Medicare & Medicaid Services 30-day stroke mortality and 30-day stroke readmission measures, concerns were expressed that these measures were not adequately designed because they do not include a valid initial stroke severity measure, such as the National Institutes of Health Stroke Scale. These outcome measures, as currently constructed, may be prone to mischaracterizing the quality of stroke care being delivered by hospitals and may ultimately harm acute ischemic stroke patients. This article details (1) why the Centers for Medicare & Medicaid Services acute ischemic stroke outcome measures in their present form may not provide adequate risk adjustment, (2) why the measures as currently designed may lead to inaccurate representation of hospital performance and have the potential for serious unintended consequences, (3) what activities the American Heart Association/American Stroke Association has engaged in to highlight these concerns to the Centers for Medicare & Medicaid Services and other interested parties, and (4) alternative approaches and opportunities that should be considered for more accurately risk-adjusting 30-day outcomes measures in patients with ischemic stroke.

Developing a stroke severity index based on administrative data was feasible using data mining techniques.

PubMed

Sung, Sheng-Feng; Hsieh, Cheng-Yang; Kao Yang, Yea-Huei; Lin, Huey-Juan; Chen, Chih-Hung; Chen, Yu-Wei; Hu, Ya-Han

2015-11-01

Case-mix adjustment is difficult for stroke outcome studies using administrative data. However, relevant prescription, laboratory, procedure, and service claims might be surrogates for stroke severity. This study proposes a method for developing a stroke severity index (SSI) by using administrative data. We identified 3,577 patients with acute ischemic stroke from a hospital-based registry and analyzed claims data with plenty of features. Stroke severity was measured using the National Institutes of Health Stroke Scale (NIHSS). We used two data mining methods and conventional multiple linear regression (MLR) to develop prediction models, comparing the model performance according to the Pearson correlation coefficient between the SSI and the NIHSS. We validated these models in four independent cohorts by using hospital-based registry data linked to a nationwide administrative database. We identified seven predictive features and developed three models. The k-nearest neighbor model (correlation coefficient, 0.743; 95% confidence interval: 0.737, 0.749) performed slightly better than the MLR model (0.742; 0.736, 0.747), followed by the regression tree model (0.737; 0.731, 0.742). In the validation cohorts, the correlation coefficients were between 0.677 and 0.725 for all three models. The claims-based SSI enables adjusting for disease severity in stroke studies using administrative data. Copyright © 2015 Elsevier Inc. All rights reserved.

Status and Future Perspectives of Utilizing Big Data in Neurosurgical and Stroke Research

PubMed Central

NISHIMURA, Ataru; NISHIMURA, Kunihiro; KADA, Akiko; IIHARA, Koji

2016-01-01

The management, analysis, and integration of Big Data have received increasing attention in healthcare research as well as in medical bioinformatics. The J-ASPECT study is the first nationwide survey in Japan on the real-world setting of stroke care using data obtained from the diagnosis procedure combination-based payment system. The J-ASPECT study demonstrated a significant association between comprehensive stroke care (CSC) capacity and the hospital volume of stroke interventions in Japan; further, it showed that CSC capabilities were associated with reduced in-hospital mortality rates. Our study aims to create new evidence and insight from ‘real world’ neurosurgical practice and stroke care in Japan using Big Data. The final aim of this study is to develop effective methods to bridge the evidence-practice gap in acute stroke healthcare. In this study, the authors describe the status and future perspectives of the development of a new method of stroke registry as a powerful tool for acute stroke care research. PMID:27680330

Design and test of a Microsoft Kinect-based system for delivering adaptive visual feedback to stroke patients during training of upper limb movement.

PubMed

Simonsen, Daniel; Popovic, Mirjana B; Spaich, Erika G; Andersen, Ole Kæseler

2017-11-01

The present paper describes the design and test of a low-cost Microsoft Kinect-based system for delivering adaptive visual feedback to stroke patients during the execution of an upper limb exercise. Eleven sub-acute stroke patients with varying degrees of upper limb function were recruited. Each subject participated in a control session (repeated twice) and a feedback session (repeated twice). In each session, the subjects were presented with a rectangular pattern displayed on a vertical mounted monitor embedded in the table in front of the patient. The subjects were asked to move a marker inside the rectangular pattern by using their most affected hand. During the feedback session, the thickness of the rectangular pattern was changed according to the performance of the subject, and the color of the marker changed according to its position, thereby guiding the subject's movements. In the control session, the thickness of the rectangular pattern and the color of the marker did not change. The results showed that the movement similarity and smoothness was higher in the feedback session than in the control session while the duration of the movement was longer. The present study showed that adaptive visual feedback delivered by use of the Kinect sensor can increase the similarity and smoothness of upper limb movement in stroke patients.

Nighttime observations of thunderstorm electrical activity from a high altitude airplane

NASA Technical Reports Server (NTRS)

Brook, M.; Rhodes, C.; Vaughan, O. H., Jr.; Orville, R. E.; Vonnegut, B.

1984-01-01

Photographs from a NASA U-2 airplane flying over nocturnal thunderstorms show frequent lightning activity in the upper part of the cloud. In some cases, unobscured segments of lightning channels 1 km or longer are visible in clear air around and above the cloud. Multiple images of lightning channels indicate multiple discharges in the same channel. Photographs taken through a diffraction grating show that the lightning has a spectrum similar to that observed in the lower troposphere. Lightning spectra obtained with a slitless line-scan spectrometer show strong singly ionized nitrogen emissions at 463.0 and 500.5 nm. Field changes measured with an electric field-change meter correlate with pulses measured with a photocell optical system. Optical signals corresponding to dart leader, return stroke, and continuing current events are readily distinguished in the scattered light emerging from the cloud surface. The variation of light intensity with time in lightning events is consistent with predicted modification of optical lightning signals by clouds. It appears that satellite based optical sensor measurements cannot provide reliable information on current rise times in return strokes. On the other hand, discrimination between cloud-to-ground and intracloud flashes and the counting of ground strokes is possible using the optical pulse pairs which have been identified with leader, return-stroke events in the cloud-to-ground flashes studied.

A Review of Stroke Research in Malaysia from 2000 - 2014.

PubMed

Cheah, W K; Hor, C P; Zariah, A A; Looi, I

2016-06-01

Over 100 articles related to stroke were found in a search through a database dedicated to indexing all literature with original data involving the Malaysian population between years 2000 and 2014. Stroke is emerging as a major public health problem. The development of the National Stroke Registry in the year 2009 aims to coordinate and improve stroke care, as well as to generate more data on various aspects of stroke in the country. Studies on predictors of survival after strokes have shown potential to improve the overall management of stroke, both during acute event and long term care. Stroke units were shown to be effective locally in stroke outcomes and prevention of stroke-related complications. The limited data looking at direct cost of stroke management suggests that the health economic burden in stroke management may be even higher. Innovative rehabilitation programmes including braincomputer interface technology were studied with encouraging results. Studies in traditional complementary medicine for strokes such as acupuncture, Urut Melayu and herbal medicine were still limited.

Burden of stroke in Bangladesh.

PubMed

Islam, Md Nazmul; Moniruzzaman, Mohammed; Khalil, Md Ibrahim; Basri, Rehana; Alam, Mohammad Khursheed; Loo, Keat Wei; Gan, Siew Hua

2013-04-01

Stroke is the third leading cause of death in Bangladesh. The World Health Organization ranks Bangladesh's mortality rate due to stroke as number 84 in the world. The reported prevalence of stroke in Bangladesh is 0.3%, although no data on stroke incidence have been recorded. Hospital-based studies conducted in past decades have indicated that hypertension is the main cause of ischaemic and haemorrhagic stroke in Bangladesh. The high number of disability-adjusted life-years lost due to stroke (485 per 10,000 people) show that stroke severely impacts Bangladesh's economy. Although two non-governmental organizations, BRAC and the Centre for the Rehabilitation of the Paralysed, are actively involved in primary stroke prevention strategies, the Bangladeshi government needs to emphasize healthcare development to cope with the increasing population density and to reduce stroke occurrence. © 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.

Feasibility of a smartphone-based balance assessment system for subjects with chronic stroke.

PubMed

Hou, You-Ruei; Chiu, Ya-Lan; Chiang, Shang-Lin; Chen, Hui-Ya; Sung, Wen-Hsu

2018-07-01

Stroke is a cerebral artery disease that may lead to long-term disabilities or death. Patients that survive a stroke usually suffer balance impairments, which affect their performance in activities of daily living (ADLs) and quality of life (QoL). In recent years, smartphones have become very popular and have many capabilities. Smartphone built-in sensors have shown their ability and potential in balance performance assessment. However, the feasibility of smartphones on subjects with chronic strokes remains to be proved. Therefore, the purpose of this study is to evaluate the feasibility of a smartphone-based balance assessment system for subjects with chronic stroke. Ten subjects with chronic stroke and thirteen healthy adults were recruited in the study. The smartphone HTC 10 (HTC Corporation, Taiwan) was used to perform the balance assessment, and its built-in accelerometer and gyroscope were used to record data from the subjects. Six postures were tested for thirty seconds each: shoulder-width stance (SWS) with eyes opened (E/O) and eyes closed (E/C), feet-together stance (FTS) with E/O and E/C, and semi-tandem stance (STS) with E/O and E/C. The smartphone was fixed to the back of subjects at the second sacral spine (S2) level. The changes registered in the accelerometer and gyroscope data were used to represent the balance performance, in which higher values indicate more instability. Data was analyzed using the independent t-test with the software SPSS 20, and the statistical significance level was set to α < 0.05. Significant difference in the acceleration data was found among subjects with chronic stroke and healthy adults under four assessment postures: SWS with E/C (p = 0.048), FTS with E/O (p = 0.027), FTS with E/C (p = 0.000), and STS with E/C (p = 0.048). Furthermore, according to the gyroscope data, there were significant differences in how the two groups performed the postures. The results demonstrate that a smartphone with a built-in accelerometer and gyroscope can be used to classify balance performances between healthy adults and subjects with chronic stroke. This study shows that smartphones are feasible to assess balance for subjects with chronic stroke. Copyright © 2018 Elsevier B.V. All rights reserved.

Clinical Implications of Technological Advances in Screening for Atrial Fibrillation.

PubMed

Singh, Nikhil; Chun, Sung; Hadley, David; Froelicher, Victor

The incidence of atrial fibrillation (AF) continues to increase worldwide as people live longer. AF is the leading cause of stroke among patients older than 75 years and is responsible for at least 15% of all strokes. Industry has responded to this problem with a plethora of monitoring devices. These include single lead ECG adhesive sensors, implantable loop recorders, smartphone attachments and wearables. This review will concentrate on clinical studies using these technologies. There are wearables including watches and watch-like devices that will be mentioned but these have not been validated for clinical use. This review will begin with a background regarding screening for AF and at the end present findings from Cardiac Implantable devices that could influence use of the new mobile health technologies. Copyright © 2018 Elsevier Inc. All rights reserved.

Countries with women inequalities have higher stroke mortality.

PubMed

Kim, Young Dae; Jung, Yo Han; Caso, Valeria; Bushnell, Cheryl D; Saposnik, Gustavo

2017-10-01

Background Stroke outcomes can differ by women's legal or socioeconomic status. Aim We investigated whether differences in women's rights or gender inequalities were associated with stroke mortality at the country-level. Methods We used age-standardized stroke mortality data from 2008 obtained from the World Health Organization. We compared female-to-male stroke mortality ratio and stroke mortality rates in women and men between countries according to 50 indices of women's rights from Women, Business and the Law 2016 and Gender Inequality Index from the Human Development Report by the United Nations Development Programme. We also compared stroke mortality rate and income at the country-level. Results In our study, 176 countries with data available on stroke mortality rate in 2008 and indices of women's rights were included. There were 46 (26.1%) countries where stroke mortality in women was higher than stroke mortality in men. Among them, 29 (63%) countries were located in Sub-Saharan African region. After adjusting by country income level, higher female-to-male stroke mortality ratio was associated with 14 indices of women's rights, including differences in getting a job or opening a bank account, existence of domestic violence legislation, and inequalities in ownership right to property. Moreover, there was a higher female-to-male stroke mortality ratio among countries with higher Gender Inequality Index (r = 0.397, p < 0.001). Gender Inequality Index was more likely to be associated with stroke mortality rate in women than that in men (p < 0.001). Conclusions Our study suggested that the gender inequality status is associated with women's stroke outcomes.

Using theory to develop an exercise intervention for patients post stroke.

PubMed

Shaughnessy, Marianne; Resnick, Barbara M

2009-01-01

Stroke remains a leading cause of disability for older adults. While is it well established in the literature that exercise programs can have significant benefit, many stroke survivors do not receive specific recommendations for exercise or lack the motivation to continue exercising following discharge from rehabilitation. This article describes an exercise intervention developed for subacute stroke survivors that utilizes the self-efficacy theory framework. The rationale for selection of this theoretical framework and specific examples of interventions linked to components of the model are provided. The article describes the motivational/educational program and the sequential follow-up designed to prepare stroke survivors to increase exercise behavior. Theoretical frameworks are useful tools for guiding and organizing research investigations from literature review through development and implementation of the intervention to interpretation of findings.

Development and validation of a patient-reported outcome measure for stroke patients.

PubMed

Luo, Yanhong; Yang, Jie; Zhang, Yanbo

2015-05-08

Family support and patient satisfaction with treatment are crucial for aiding in the recovery from stroke. However, current validated stroke-specific questionnaires may not adequately capture the impact of these two variables on patients undergoing clinical trials of new drugs. Therefore, the aim of this study was to develop and evaluate a new stroke patient-reported outcome measure (Stroke-PROM) instrument for capturing more comprehensive effects of stroke on patients participating in clinical trials of new drugs. A conceptual framework and a pool of items for the preliminary Stroke-PROM were generated by consulting the relevant literature and other questionnaires created in China and other countries, and interviewing 20 patients and 4 experts to ensure that all germane parameters were included. During the first item-selection phase, classical test theory and item response theory were applied to an initial scale completed by 133 patients with stroke. During the item-revaluation phase, classical test theory and item response theory were used again, this time with 475 patients with stroke and 104 healthy participants. During the scale assessment phase, confirmatory factor analysis was applied to the final scale of the Stroke-PROM using the same study population as in the second item-selection phase. Reliability, validity, responsiveness and feasibility of the final scale were tested. The final scale of Stroke-PROM contained 46 items describing four domains (physiology, psychology, society and treatment). These four domains were subdivided into 10 subdomains. Cronbach's α coefficients for the four domains ranged from 0.861 to 0.908. Confirmatory factor analysis supported the validity of the final scale, and the model fit index satisfied the criterion. Differences in the Stroke-PROM mean scores were significant between patients with stroke and healthy participants in nine subdomains (P < 0.001), indicating that the scale showed good responsiveness. The Stroke-PROM is a patient-reported outcome multidimensional questionnaire developed especially for clinical trials of new drugs and is focused on issues of family support and patient satisfaction with treatment. Extensive data analyses supported the validity, reliability and responsiveness of the Stroke-PROM.

[Clinical applications of molecular imaging methods for patients with ischemic stroke].

PubMed

Yamauchi, Hiroshi; Fukuyama, Hidenao

2007-02-01

Several molecular imaging methods have been developed to visualize pathophysiology of cerebral ischemia in humans in vivo. PET and SPECT with specific ligands have been mainly used as diagnostic tools for the clinical usage of molecular imaging in patients with ischemic stroke. Recently, cellular MR imaging with specific contrast agents has been developed to visualize targeted cells in human stroke patients. This article reviews the current status in the clinical applications of those molecular imaging methods for patients with ischemic stroke.

Best practice guidelines for stroke in Cameroon: An innovative and participatory knowledge translation project.

PubMed

Cockburn, Lynn; Fanfon, Timothy N; Bramall, Alexa; Ngole, Eta M; Kuwoh, Pius; Anjonga, Emmanuel; Difang, Brenda M E; Kiani, Shirin; Muso, Petra S; Trivedi, Navjyot; Sama, Julius; Teboh, Sylvian

2014-01-01

Although the adherence to stroke guidelines in high-income countries has been shown to be associated with improved patient outcomes, the research, development and implementation of rehabilitation related guidelines in African countries is lacking. The purpose of this article is to describe how a group of front-line practitioners collaborated with academics and students to develop best practice guidelines (BPG) for the management and rehabilitation of stroke in adult patients in Cameroon. A working group was established and adapted internationally recognised processes for the development of best practice guidelines. The group determined the scope of the guidelines, documented current practices, and critically appraised evidence to develop guidelines relevant to the Cameroon context. The primary result of this project is best practice guidelines which provided an overview of the provision of stroke rehabilitation services in the region, and made 83 practice recommendations to improve these services. We also report on the successes and challenges encountered during the process, and the working group's recommendations aimed at encouraging others to consider similar projects. This project demonstrated that there is interest and capacity for improving stroke rehabilitation practices and for stroke guideline development in Africa.

75 FR 3475 - National Institute Of Neurological Disorders and Stroke; Notice of Meetings

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-21

... Neurological Disorders and Stroke; Notice of Meetings Pursuant to section 10(d) of the Federal Advisory... Neurological Disorders and Stroke Council. The meetings will be open to the public as indicated below, with... Committee: National Advisory Neurological Disorders and Stroke Council; Training, Career Development, and...

The Vocational Rehabilitation of Stroke Victims: Description and Prediction

ERIC Educational Resources Information Center

Lugar, Owen; Kelz, James

1971-01-01

The purpose of the study was to predict the outcome of a stroke victim's vocational rehabilitation through the use of demographic and medical data. Characteristics of stroke clients were used to develop an eight-factor stroke rating scale. Recommendations for further refinement of the scale were included. (Author)

Provision of inpatient rehabilitation and challenges experienced with participation post discharge: quantitative and qualitative inquiry of African stroke patients.

PubMed

Rhoda, Anthea; Cunningham, Natalie; Azaria, Simon; Urimubenshi, Gerard

2015-09-28

The provision of rehabilitation differs between developed and developing countries, this could impact on the outcomes of post stroke rehabilitation. The aim of this paper is to present provision of in-patient stroke rehabilitation. In addition the challenges experienced by the individuals with participation post discharge are also presented. Qualitative and quantitative research methods were used to collect data. The quantitative data was collected using a retrospective survey of stroke patients admitted to hospitals over a three- to five-year period. Quantitative data was captured on a validated data capture sheet and analysed descriptively. The qualitative data was collected using interviews from a purposively and conveniently selected sample, audio-taped and analysed thematically. The qualitative data was presented within the participation model. A total of 168 medical folders were reviewed for a South African sample, 139 for a Rwandan sample and 145 for a Tanzanian sample. The mean age ranged from 62.6 (13.78) years in the South African sample to 56.0 (17.4) in the Rwandan sample. While a total of 98 % of South African stroke patients received physiotherapy, only 39.4 % of Rwandan patients received physiotherapy. From the qualitative interviews, it became clear that the stroke patients had participation restrictions. When conceptualised within the Participation Model participation restrictions experienced by the stroke patients were a lack of accomplishment, inability to engage in previous roles and a perception of having health problems. With the exception of Rwanda, stroke patients in the countries studied are admitted to settings early post stroke allowing for implementation of effective acute interventions. The participants were experiencing challenges which included a lack of transport and the physical geographic surroundings in the rural settings not being conducive to wheelchair use. Stroke patients admitted to hospitals in certain African countries could receive limited in-patient therapeutic interventions. With the exception of barriers in the physical environment, stroke patients in developing countries where resources are limited experience the same participation restrictions as their counterparts in developed countries where resources are more freely available. Rehabilitation interventions in these developing countries should therefore be community-based focussing on intervening in the physical environment.

Consequences of Stroke in Community-Dwelling Elderly: The Health and Retirement Study 1998-2008

PubMed Central

Divani, Afshin A.; Majidi, Shahram; Barrett, Anna M.; Noorbaloochi, Siamak; Luft, Andreas R.

2011-01-01

Background and Purpose Stroke survivors are at risk of developing co-morbidities that further reduce their quality of life. The purpose of this study was to determine the risk of developing a secondary health problem after stroke. Methods We performed a case-control analysis using six biennial interview waves (1998 to 2008) of the Health and Retirement Study. We compared 631 non-institutionalized individuals who had suffered a single stroke to 631 controls matched for age, gender and interview-wave. We studied sleep problems, urinary incontinence (UI), motor impairment, falls and memory deficits among the two groups. Results Stroke survivors frequently developed new or worsened motor impairment (33%), sleep problems (up to 33%), falls (30%), UI (19%), and memory deficits (9%). As compared with controls, the risk of developing a secondary health problem was highest for memory deficits (OR: 2.45, 95%CI: 1.34-4.46), followed by UI (OR: 1.86, 95%CI: 1.31-2.66), motor impairment (OR: 1.61, 95%CI: 1.16-2.24), falls (OR: 1.5, 95%CI: 1.12-2.0) and sleep disturbances (OR: 1.49, 95%CI: 1.09-2.03). In contrast, stroke survivors were not more likely to injure themselves during a fall (OR: 1.14, 95%CI: 0.72-1.79). After adjusting for cardiovascular risk factors, social status, psychiatric symptoms and pain, the risks of falling or developing sleep problems were not different from the control subjects. Conclusions The risk of developing a secondary health problem that can impact daily life is markedly increased after stroke. A better understanding of frequencies and risks for secondary health problems after stroke are necessary for designing better preventive and rehabilitation strategies. PMID:21597018

Developing a personalised self-management system for post stroke rehabilitation; utilising a user-centred design methodology.

PubMed

Mawson, Susan; Nasr, Nasrin; Parker, Jack; Zheng, Huiru; Davies, Richard; Mountain, Gail

2014-11-01

To develop and evaluate an information and communication technology (ICT) solution for a post-stroke Personalised Self-Managed Rehabilitation System (PSMrS). The PSMrS translates current models of stroke rehabilitation and theories underpinning self-management and self-efficacy into an ICT-based system for home-based post-stroke rehabilitation. The interdisciplinary research team applied a hybrid of health and social sciences research methods and user-centred design methods. This included a series of home visits, focus groups, in-depth interviews, cultural probes and technology biographies. The iterative development of both the content of the PSMrS and the interactive interfaces between the system and the user incorporates current models of post-stroke rehabilitation and addresses the factors that promote self-managed behaviour and self-efficacy such as mastery, verbal persuasion and physiological feedback. The methodological approach has ensured that the interactive technology has been driven by the needs of the stroke survivors and their carers in the context of their journey to both recovery and adaptation. Underpinned by theories of motor relearning, neuroplasticity, self-management and behaviour change, the PSMrS developed in this study has resulted in a personalised system for self-managed rehabilitation, which has the potential to change motor behaviour and promote the achievement of life goals for stroke survivors.

Standardizing the structure of stroke clinical and epidemiologic research data: the National Institute of Neurological Disorders and Stroke (NINDS) Stroke Common Data Element (CDE) project.

PubMed

Saver, Jeffrey L; Warach, Steven; Janis, Scott; Odenkirchen, Joanne; Becker, Kyra; Benavente, Oscar; Broderick, Joseph; Dromerick, Alexander W; Duncan, Pamela; Elkind, Mitchell S V; Johnston, Karen; Kidwell, Chelsea S; Meschia, James F; Schwamm, Lee

2012-04-01

The National Institute of Neurological Disorders and Stroke initiated development of stroke-specific Common Data Elements (CDEs) as part of a project to develop data standards for funded clinical research in all fields of neuroscience. Standardizing data elements in translational, clinical, and population research in cerebrovascular disease could decrease study start-up time, facilitate data sharing, and promote well-informed clinical practice guidelines. A working group of diverse experts in cerebrovascular clinical trials, epidemiology, and biostatistics met regularly to develop a set of stroke CDEs, selecting among, refining, and adding to existing, field-tested data elements from national registries and funded trials and studies. Candidate elements were revised on the basis of comments from leading national and international neurovascular research organizations and the public. The first iteration of the National Institute of Neurological Disorders and Stroke (NINDS) stroke-specific CDEs comprises 980 data elements spanning 9 content areas: (1) biospecimens and biomarkers; (2) hospital course and acute therapies; (3) imaging; (4) laboratory tests and vital signs; (5) long-term therapies; (6) medical history and prior health status; (7) outcomes and end points; (8) stroke presentation; and (9) stroke types and subtypes. A CDE website provides uniform names and structures for each element, a data dictionary, and template case report forms, using the CDEs. Stroke-specific CDEs are now available as standardized, scientifically vetted, variable structures to facilitate data collection and data sharing in cerebrovascular patient-oriented research. The CDEs are an evolving resource that will be iteratively improved based on investigator use, new technologies, and emerging concepts and research findings.

Risks of newly onset hemorrhagic stroke in patients with neovascular age-related macular degeneration.

PubMed

Lee, Wan-Ju Annabelle; Cheng, Ching-Lan; Lee, Cheng-Han; Kao Yang, Yea-Huei; Lin, Swu-Jane; Hsieh, Cheng-Yang

2017-10-01

Age-related macular degeneration (AMD) is an eye disease causing blindness in the elderly. It shares many common possible pathogenic mechanisms with cardiovascular diseases. Many studies have discussed the association between AMD and stroke, but the results were inconsistent. Our aim was to determine the associations between neovascular AMD and the risk of stroke in the Taiwanese population. This is a retrospective cohort study. We used claims data from National Health Insurance Research Database. Patients aged more than 45 years without stroke, myocardial infarction, or any AMD were selected from 2001 to 2008 and followed until 2010. The index date was defined as the date of nAMD diagnosis (ICD-9 code, 362.52). The comparison group was patients without an nAMD diagnosis with age- and sex-matched to nAMD subjects at a ratio of up to 10 to 1. Kaplan-Meier survival analysis and Cox regression analysis were used. The incidence of stroke events (ICD-9 codes, 430-434) and their subtypes (hemorrhagic and ischemic) were primary outcomes. Secondary outcomes included acute myocardial infarction (AMI), composite AMI/stroke, and all-cause mortality. Patients with nAMD had a higher risk of developing stroke, with an adjusted HR of 1.30 (95% CI, 1.01-1.68). A higher risk for hemorrhagic stroke (HR, 1.70, 95% CI, 1.03-2.83) was also found. No significant differences were observed in ischemic stroke, the composite of AMI/stroke, and all-cause mortality. Patients with nAMD had a significantly higher risk of developing stroke, which was driven mainly by the increased risk of developing the hemorrhagic subtype. Copyright © 2017 John Wiley & Sons, Ltd.

Development and validation of clinical prediction models for mortality, functional outcome and cognitive impairment after stroke: a study protocol

PubMed Central

Fahey, Marion; Rudd, Anthony; Béjot, Yannick; Wolfe, Charles; Douiri, Abdel

2017-01-01

Introduction Stroke is a leading cause of adult disability and death worldwide. The neurological impairments associated with stroke prevent patients from performing basic daily activities and have enormous impact on families and caregivers. Practical and accurate tools to assist in predicting outcome after stroke at patient level can provide significant aid for patient management. Furthermore, prediction models of this kind can be useful for clinical research, health economics, policymaking and clinical decision support. Methods 2869 patients with first-ever stroke from South London Stroke Register (SLSR) (1995–2004) will be included in the development cohort. We will use information captured after baseline to construct multilevel models and a Cox proportional hazard model to predict cognitive impairment, functional outcome and mortality up to 5 years after stroke. Repeated random subsampling validation (Monte Carlo cross-validation) will be evaluated in model development. Data from participants recruited to the stroke register (2005–2014) will be used for temporal validation of the models. Data from participants recruited to the Dijon Stroke Register (1985–2015) will be used for external validation. Discrimination, calibration and clinical utility of the models will be presented. Ethics Patients, or for patients who cannot consent their relatives, gave written informed consent to participate in stroke-related studies within the SLSR. The SLSR design was approved by the ethics committees of Guy’s and St Thomas’ NHS Foundation Trust, Kings College Hospital, Queens Square and Westminster Hospitals (London). The Dijon Stroke Registry was approved by the Comité National des Registres and the InVS and has authorisation of the Commission Nationale de l’Informatique et des Libertés. PMID:28821511

Combined Heat & Power Using the Infinia Concentrated Solar CHP PowerDish System

DTIC Science & Technology

2013-08-01

been due to a temperature induced reduction in magnetic field strength (inside the generator) that in turn can cause a generator over-stroke which can... Measurements and Sensors 34 Table 4: Results Summary Performance Objectives (same as Table 2) 38 Table 5: Building 9246 Energy Consumption vs...and Building Measurement Instrumentation P&ID 28 Figure 12: Building 9246 Radiant Heating and Hot Water Equipment 29 Figure 13: Coolant Flow

Monitoring Hitting Load in Tennis Using Inertial Sensors and Machine Learning.

PubMed

Whiteside, David; Cant, Olivia; Connolly, Molly; Reid, Machar

2017-10-01

Quantifying external workload is fundamental to training prescription in sport. In tennis, global positioning data are imprecise and fail to capture hitting loads. The current gold standard (manual notation) is time intensive and often not possible given players' heavy travel schedules. To develop an automated stroke-classification system to help quantify hitting load in tennis. Nineteen athletes wore an inertial measurement unit (IMU) on their wrist during 66 video-recorded training sessions. Video footage was manually notated such that known shot type (serve, rally forehand, slice forehand, forehand volley, rally backhand, slice backhand, backhand volley, smash, or false positive) was associated with the corresponding IMU data for 28,582 shots. Six types of machine-learning models were then constructed to classify true shot type from the IMU signals. Across 10-fold cross-validation, a cubic-kernel support vector machine classified binned shots (overhead, forehand, or backhand) with an accuracy of 97.4%. A second cubic-kernel support vector machine achieved 93.2% accuracy when classifying all 9 shot types. With a view to monitoring external load, the combination of miniature inertial sensors and machine learning offers a practical and automated method of quantifying shot counts and discriminating shot types in elite tennis players.

Real-time estimation of paracellular permeability of cerebral endothelial cells by capacitance sensor array

NASA Astrophysics Data System (ADS)

Hyun Jo, Dong; Lee, Rimi; Hyoung Kim, Jin; Oh Jun, Hyoung; Geol Lee, Tae; Hun Kim, Jeong

2015-06-01

Vascular integrity is important in maintaining homeostasis of brain microenvironments. In various brain diseases including Alzheimer’s disease, stroke, and multiple sclerosis, increased paracellular permeability due to breakdown of blood-brain barrier is linked with initiation and progression of pathological conditions. We developed a capacitance sensor array to monitor dielectric responses of cerebral endothelial cell monolayer, which could be utilized to evaluate the integrity of brain microvasculature. Our system measured real-time capacitance values which demonstrated frequency- and time-dependent variations. With the measurement of capacitance at the frequency of 100 Hz, we could differentiate the effects of vascular endothelial growth factor (VEGF), a representative permeability-inducing factor, on endothelial cells and quantitatively analyse the normalized values. Interestingly, we showed differential capacitance values according to the status of endothelial cell monolayer, confluent or sparse, evidencing that the integrity of monolayer was associated with capacitance values. Another notable feature was that we could evaluate the expression of molecules in samples in our system with the reference of real-time capacitance values. We suggest that this dielectric spectroscopy system could be successfully implanted as a novel in vitro assay in the investigation of the roles of paracellular permeability in various brain diseases.

A new paradigm for primary prevention strategy in people with elevated risk of stroke.

PubMed

Feigin, Valery L; Norrving, Bo

2014-07-01

Existing methods of primary stroke prevention are not sufficiently effective. Based on the recently developed Stroke Riskometer app, a new 'mass-elevated risk stroke/cardiovascular disease prevention' approach as an addition to the currently adopted absolute risk stroke/cardiovascular disease prevention approach is being advocated. We believe this approach is far more appealing to the individuals concerned and could be as efficient as the conventional population-based approach because it allows identification and engagement in prevention of all individuals who are at an increased (even slightly increased) risk of stroke and cardiovascular disease. The key novelty of this approach is twofold. First, it utilizes modern far-reaching mobile technologies, allowing individuals to calculate their absolute risk of stroke within the next 5 to 10 years and to compare their risk with those of the same age and gender without risk factors. Second, it employs self-management strategies to engage the person concerned in stroke/cardiovascular disease prevention, which is tailored to the person's individual risk profile. Preventative strategies similar to the Stroke Riskometer could be developed for other non-communicable disorders for which reliable predictive models and preventative recommendations exist. This would help reduce the burden of non-communicable disorders worldwide. © 2014 The Authors. International Journal of Stroke published by John Wiley & Sons Ltd on behalf of World Stroke Organization.

Increased stroke risk in Bell's palsy patients without steroid treatment.

PubMed

Lee, C-C; Su, Y-C; Chien, S-H; Ho, H-C; Hung, S-K; Lee, M-S; Chou, P; Chiu, B C-H; Huang, Y-S

2013-04-01

To investigate the risk of stroke development following a diagnosis of Bell's palsy in a nationwide follow-up study. Information on Bell's palsy and other factors relevant for stroke was obtained for 433218 eligible subjects without previous stroke who had ambulatory visit in 2004. Of those, 897 patients with Bell's palsy were identified. Over a median 2.9 years of follow-up, 4581 incident strokes were identified. We estimated hazard ratios (HR) and 95% confidence intervals [CI] with Cox proportional hazard models adjusting for age, sex, co-morbidities, and important risk factors. Standardized incidence ratio of stroke amongst patients with Bell's palsy was analyzed. Compared with non-Bell's palsy patients, patients with Bell's palsy had a 2.02-times (95% CI, 1.42-2.86) higher risk of stroke. The adjusted HR of developing stroke for patients with Bell's palsy treated with and without systemic steroid were 1.67 (95% CI, 0.69-4) and 2.10 (95%, 1.40-3.07), respectively. Patients with Bell's palsy carry a higher risk of stroke than the general population. Our data suggest that these patients might benefit from a more intensive stroke prevention therapy and regular follow-up after initial diagnosis. © 2012 The Author(s) European Journal of Neurology © 2012 EFNS.

Implementation of evidence-based stroke care: enablers, barriers, and the role of facilitators

PubMed Central

Purvis, Tara; Moss, Karen; Denisenko, Sonia; Bladin, Chris; Cadilhac, Dominique A

2014-01-01

A stroke care strategy was developed in 2007 to improve stroke services in Victoria, Australia. Eight stroke network facilitators (SNFs) were appointed in selected hospitals to enable the establishment of stroke units, develop thrombolysis services, and implement protocols. We aimed to explain the main issues being faced by clinicians in providing evidence-based stroke care, and to determine if the appointment of an SNF was perceived as an acceptable strategy to improve stroke care. Face-to-face semistructured interviews were used in a qualitative research design. Interview transcripts were verified by respondents prior to coding. Two researchers conducted thematic analysis of major themes and subthemes. Overall, 84 hospital staff participated in 33 interviews during 2008. The common factors found to impact on stroke care included staff and equipment availability, location of care, inconsistent use of clinical pathways, and professional beliefs. Other barriers included limited access to specialist clinicians and workload demands. The establishment of dedicated stroke units was considered essential to improve the quality of care. The SNF role was valued for identifying gaps in care and providing capacity to change clinical processes. This is the first large, qualitative multicenter study to describe issues associated with delivering high-quality stroke care and the potential benefits of SNFs to facilitate these improvements. PMID:25246799

Impact of metabolic syndrome components on incident stroke subtypes: a Chinese cohort study.

PubMed

Chen, Y-C; Sun, C-A; Yang, T; Chu, C-H; Bai, C-H; You, S-L; Hwang, L-C; Chen, C-H; Wei, C-Y; Chou, Y-C

2014-11-01

Limited evidence is available on the risk differences in the development of stroke subtypes in relation to particular clustering patterns of the metabolic syndrome (MetS) components. A follow-up study of a Chinese cohort involving 10,292 individuals was performed to assess the roles of cluster patterns of the MetS components in the prediction of incident stroke subtypes. During follow-up, there were 161 incident cases of ischemic strokes and 41 incident cases of hemorrhagic strokes. Among MetS components, only the hypertensive trait was associated with significantly elevated risks of both ischemic and hemorrhagic strokes. Furthermore, MetS with hypertension as components was associated with increased risk of ischemic and hemorrhagic strokes (adjusted hazards ratio (95% confidence interval) was 2.96 (1.94-4.50) and 2.93 (1.25-6.90), respectively) as compared with those who had neither hypertension nor MetS. Notably, as the number of the MetS components increased, the risk of ischemic stroke significantly and dose-dependently increased. This implies a cumulative effect of MetS components in elevating the risk of ischemic stroke. These findings suggest that MetS comprises heterogenous clusters with respect to the risk of developing the subtype of stroke.

Exploring views on long term rehabilitation for people with stroke in a developing country: findings from focus group discussions

PubMed Central

2014-01-01

Background The importance of long term rehabilitation for people with stroke is increasingly evident, yet it is not known whether such services can be materialised in countries with limited community resources. In this study, we explored the perception of rehabilitation professionals and people with stroke towards long term stroke rehabilitation services and potential approaches to enable provision of these services. Views from providers and users are important in ensuring whatever strategies developed for long term stroke rehabilitations are feasible and acceptable. Methods Focus group discussions were conducted involving 15 rehabilitation professionals and eight long term stroke survivors. All recorded conversations were transcribed verbatim and analysed using the principles of qualitative research. Results Both groups agreed that people with stroke may benefit from more rehabilitation compared to the amount of rehabilitation services presently provided. Views regarding the unavailability of long term rehabilitation services due to multi-factorial barriers were recognised. The groups also highlighted the urgent need for the establishment of community-based stroke rehabilitation centres. Family-assisted home therapy was viewed as a potential approach to continued rehabilitation for long term stroke survivors, given careful planning to overcome several family-related issues. Conclusions Barriers to the provision of long term stroke rehabilitation services are multi-factorial. Establishment of community-based stroke rehabilitation centres and training family members to conduct home-based therapy are two potential strategies to enable the continuation of rehabilitation for long term stroke survivors. PMID:24606911

Examining Differences in Patterns of Sensory and Motor Recovery After Stroke With Robotics.

PubMed

Semrau, Jennifer A; Herter, Troy M; Scott, Stephen H; Dukelow, Sean P

2015-12-01

Developing a better understanding of the trajectory and timing of stroke recovery is critical for developing patient-centered rehabilitation approaches. Here, we quantified proprioceptive and motor deficits using robotic technology during the first 6 months post stroke to characterize timing and patterns in recovery. We also make comparisons of robotic assessments to traditional clinical measures. One hundred sixteen subjects with unilateral stroke were studied at 4 time points: 1, 6, 12, and 26 weeks post stroke. Subjects performed robotic assessments of proprioceptive (position sense and kinesthesia) and motor function (unilateral reaching task and bimanual object hit task), as well as several clinical measures (Functional Independence Measure, Purdue Pegboard, and Chedoke-McMaster Stroke Assessment). One week post stroke, many subjects displayed proprioceptive (48% position sense and 68% kinesthesia) and motor impairments (80% unilateral reaching and 85% bilateral movement). Interindividual recovery on robotic measures was highly variable. However, we characterized recovery as early (normal by 6 weeks post stroke), late (normal by 26 weeks post stroke), or incomplete (impaired at 26 weeks post stroke). Proprioceptive and motor recovery often followed different timelines. Across all time points, robotic measures were correlated with clinical measures. These results highlight the need for more sensitive, targeted identification of sensory and motor deficits to optimize rehabilitation after stroke. Furthermore, the trajectory of recovery for some individuals with mild to moderate stroke may be much longer than previously considered. © 2015 American Heart Association, Inc.

The economics of atrial fibrillation: a time for review and prioritization.

PubMed

Cadilhac, Dominique A

2012-08-01

Stroke associated with atrial fibrillation may occur in up to one third of people who experience an ischemic event, and results in greater stroke severity and poorer health outcomes. The ageing population in developed and developing countries will lead to an increase in the prevalence of atrial fibrillation in society. Detecting people who have atrial fibrillation and ensuring optimal prevention management is essential for reducing the burden of stroke worldwide. There is evidence that use of anticoagulants is inadequate in primary and secondary prevention of stroke. New anticoagulants that have fewer side effects and population screening tools are available. However, there is little information available about the cost-effectiveness of these new options for atrial fibrillation detection and stroke prevention management over current practice. Since resources for spending in health are limited, it is essential that formal economic analyses are undertaken to ensure there are informed and evidence-based decisions on where to best invest stroke prevention resources. It is essential that renewed efforts in the area of atrial fibrillation and options for stroke prevention are undertaken within the public health research community. © 2012 The Author. International Journal of Stroke © 2012 World Stroke Organization.

Thunderstorm monitoring with VLF network and super dense meteorological observation system

NASA Astrophysics Data System (ADS)

Takahashi, Yukihiro; Sato, Mitsuteru

2015-04-01

It's not easy to understand the inside structure and developing process of thunderstorm only with existing meteorological instruments since its horizontal extent of the storm cell is sometimes smaller than an order of 10 km while one of the densest ground network in Japan, AMEDAS, consists of sites located every 17 km in average and the resolution of meteorological radar is 1-2 km in general. Even the X-band radar realizes the resolution of 250 m or larger. Here we suggest a thunderstorm monitoring system consisting of the network of VLF radio wave receivers and the super dense meteorological observation system with simple and low cost plate-type sensors that can be used for measurement both of raindrop and vertical electric field change caused by cloud-to-ground lightning discharge, adding to basic equipments for meteorological measurements. The plate-type sensor consists of two aluminum plates with a diameter of 10-20 cm. We carried out an observation campaign in summer of 2013 in the foothills of Mt. Yastugatake, Yamanashi and Nagano prefectures in Japan, installing 6 plate-type sensors at a distance of about 4 km. Horizontal location, height and charge amount of each lightning discharge are estimated successfully based on the information of electric field changes at several observing sites. Moreover, it was found that the thunderstorm has a very narrow structure smaller than 300 m that cannot be measured by any other ways, counting the positive and negative pulses caused by attachment of raindrop to the sensor plate, respectively. We plan to construct a new super dense observation network in the north Kanto region, Japan, where the lightning activity is most prominent in summer Japan and surrounded by our VLF systems developed for detecting sferics from lightning discharge, distributing more than several tens of sensors at every 4 km or shorter, such as an order of 100 m at minimum. This kind of new type network will reveal the unknown fine structures of thunderstorms and open the door for constructing real time alert system of torrential rainfall and lightning stroke especially in the city area.

Rehabilitation Needs of Stroke Survivors After Discharge From Hospital in India.

PubMed

Kamalakannan, Sureshkumar; Gudlavalleti Venkata, Murthy; Prost, Audrey; Natarajan, Subbulakshmy; Pant, Hira; Chitalurri, Naveen; Goenka, Shifalika; Kuper, Hannah

2016-09-01

To assess the rehabilitation needs of stroke survivors in Chennai, India, after discharge from the hospital. Mixed-methods research design. Home-based. Stroke survivors (n=50; mean age ± SD, 58.9±10.5y) and primary caregivers of these stroke survivors (n=50; mean age ± SD, 43.1±11.8y) took part in the quantitative survey. A subsample of stroke survivors (n=12), primary caregivers (n=10), and health care professionals (n=8) took part in the qualitative in-depth interviews. Not applicable. Rehabilitation needs after hospital discharge. About 82% of the needs expressed by stroke survivors and 92% of the needs expressed by caregivers indicated that they had a substantial need for information. The proportion of financial needs reported by the stroke survivors and the caregivers was 70% and 75%, respectively. The qualitative data revealed major gaps in access to stroke rehabilitation services. Service providers identified availability and affordability of services as key problems. Stroke survivors and their caregivers identified lack of information about stroke as major barriers to accessibility of stroke rehabilitation services. Caregivers expressed a tremendous need for support to manage family dynamics. The study highlights a considerable unmet need for poststroke rehabilitation services. Given the lack of rehabilitation resources in India, developing an accessible, innovative, patient-centered, culturally sensitive rehabilitation intervention is of public health importance. It is crucial for low- and middle-income countries like India to develop technology-driven stroke rehabilitation strategies to meet the growing rehabilitation needs of stroke survivors. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Development and Evaluation of a Feedback Support System with Audio and Playback Strokes

ERIC Educational Resources Information Center

Li, Kai; Akahori, Kanji

2008-01-01

This paper describes the development and evaluation of a handwritten correction support system with audio and playback strokes used to teach Japanese writing. The study examined whether audio and playback strokes have a positive effect on students using honorific expressions in Japanese writing. The results showed that error feedback with audio…

Stroke

MedlinePlus

... taking blood thinners, such as warfarin (Coumadin). Very high blood pressure may cause blood vessels to burst, leading to ... can develop bleeding and become a hemorrhagic stroke. High blood pressure is the main risk factor for strokes . Other ...

The development and implementation of stroke risk prediction model in National Health Insurance Service's personal health record.

PubMed

Lee, Jae-Woo; Lim, Hyun-Sun; Kim, Dong-Wook; Shin, Soon-Ae; Kim, Jinkwon; Yoo, Bora; Cho, Kyung-Hee

2018-01-01

The purpose of this study was to build a 10-year stroke prediction model and categorize a probability of stroke using the Korean national health examination data. Then it intended to develop the algorithm to provide a personalized warning on the basis of each user's level of stroke risk and a lifestyle correction message about the stroke risk factors. Subject to national health examinees in 2002-2003, the stroke prediction model identified when stroke was first diagnosed by following-up the cohort until 2013 and estimated a 10-year probability of stroke. It sorted the user's individual probability of stroke into five categories - normal, slightly high, high, risky, very risky, according to the five ranges of average probability of stroke in comparison to total population - less than 50 percentile, 50-70, 70-90, 90-99.9, more than 99.9 percentile, and constructed the personalized warning and lifestyle correction messages by each category. Risk factors in stroke risk model include the age, BMI, cholesterol, hypertension, diabetes, smoking status and intensity, physical activity, alcohol drinking, past history (hypertension, coronary heart disease) and family history (stroke, coronary heart disease). The AUC values of stroke risk prediction model from the external validation data set were 0.83 in men and 0.82 in women, which showed a high predictive power. The probability of stroke within 10 years for men in normal group (less than 50 percentile) was less than 3.92% and those in very risky group (top 0.01 percentile) was 66.2% and over. The women's probability of stroke within 10 years was less than 3.77% in normal group (less than 50 percentile) and 55.24% and over in very risky group. This study developed the stroke risk prediction model and the personalized warning and the lifestyle correction message based on the national health examination data and uploaded them to the personal health record service called My Health Bank in the health information website - Health iN. By doing so, it urged medical users to strengthen the motivation of health management and induced changes in their health behaviors. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Telestroke ambulances in prehospital stroke management: concept and pilot feasibility study.

PubMed

Liman, Thomas G; Winter, Benjamin; Waldschmidt, Carolin; Zerbe, Norman; Hufnagl, Peter; Audebert, Heinrich J; Endres, Matthias

2012-08-01

Pre- and intrahospital time delays are major concerns in acute stroke care. Telemedicine-equipped ambulances may improve time management and identify patients with stroke eligible for thrombolysis by an early prehospital stroke diagnosis. The aims of this study were (1) to develop a telestroke ambulance prototype; (2) to test the reliability of stroke severity assessment; and (3) to evaluate its feasibility in the prehospital emergency setting. Mobil, real-time audio-video streaming telemedicine devices were implemented into advanced life support ambulances. Feasibility of telestroke ambulances and reliability of the National Institutes of Health Stroke Scale assessment were tested using current wireless cellular communication technology (third generation) in a prehospital stroke scenario. Two stroke actors were trained in simulation of differing right and left middle cerebral artery stroke syndromes. National Institutes of Health Stroke Scale assessment was performed by a hospital-based stroke physician by telemedicine, by an emergency physician guided by telemedicine, and "a posteriori" on the basis of video documentation. In 18 of 30 scenarios, National Institutes of Health Stroke Scale assessment could not be performed due to absence or loss of audio-video signal. In the remaining 12 completed scenarios, interrater agreement of National Institutes of Health Stroke Scale examination between ambulance and hospital and ambulance and "a posteriori" video evaluation was moderate to good with weighted κ values of 0.69 (95% CI, 0.51-0.87) and 0.79 (95% CI, 0.59-0.98), respectively. Prehospital telestroke examination was not at an acceptable level for clinical use, at least on the basis of the used technology. Further technical development is needed before telestroke is applicable for prehospital stroke management during patient transport.

Predictors and assessment of cognitive dysfunction resulting from ischaemic stroke

PubMed Central

Gottesman, Rebecca F; Hillis, Argye E

2013-01-01

Stroke remains a primary cause of morbidity throughout the world mainly because of its effect on cognition. Individuals can recover from physical disability resulting from stroke, but might be unable to return to their previous occupations or independent life because of cognitive impairments. Cognitive dysfunction ranges from focal deficits, resulting directly from an area of infarction or from hypoperfusion in adjacent tissue, to more global cognitive dysfunction. Global dysfunction is likely to be related to other underlying subclinical cerebrovascular disease, such as white-matter disease or subclinical infarcts. Study of cognitive dysfunction after stroke is complicated by varying definitions and lack of measurement of cognition before stroke. Additionally, stroke can affect white-matter connectivity, so newer imaging techniques, such as diffusion-tensor imaging and magnetisation transfer imaging, that can be used to assess this subclinical injury are important tools in the assessment of cognitive dysfunction after stroke. As research is increasingly focused on the role of preventable risk factors in the development of dementia, the role of stroke in the development of cognitive impairment and dementia could be another target for prevention. PMID:20723846

Stroke Outreach in an Inner City Market: A Platform for Identifying African American Males for Stroke Prevention Interventions.

PubMed

Sharrief, Anjail Zarinah; Johnson, Brenda; Urrutia, Victor Cruz

2015-01-01

There are significant racial disparities in stroke incidence and mortality. Health fairs and outreach programs can be used to increase stroke literacy, but they often fail to reach those at highest risk, including African American males. We conducted a stroke outreach and screening program at an inner city market in order to attract a high-risk group for a stroke education intervention. A modified Framingham risk tool was used to estimate stroke risk and a 10-item quiz was developed to assess stroke literacy among 80 participants. We report results of the demographic and stroke risk analyses and stroke knowledge assessment. The program attracted a majority male (70%) and African American (95%) group of participants. Self-reported hypertension (57.5%), tobacco use (40%), and diabetes (23.8%) were prevalent. Knowledge of stroke warning signs, risk factors, and appropriate action to take for stroke symptoms was not poor when compared to the literature. Stroke outreach and screening in an inner city public market may be an effective way to target a high-risk population for stroke prevention interventions. Stroke risk among participants was high despite adequate stroke knowledge.

What is the evidence for using family based interventions to prevent stroke recurrence?

PubMed

Lawrence, Maggie; McVey, Caroline; Kerr, Susan

Stroke has a devastating impact on individuals and families. Risk factors for recurrence include lifestyle behaviours such as smoking, excessive alcohol consumption, an unhealthy diet and physical inactivity. This article describes a programme of research that aims to gather and synthesise the evidence required to inform the development and evaluation of a family centred, behavioural intervention designed to address lifestyle risk factors for recurrent stroke. We present an overview of the research undertaken to develop the evidence base. This included a survey of stroke nurse practice, a focus group study with people who had had a stroke as well as their family members, and a systematic review of the efficacy of lifestyle interventions.

Evidence-based quality indicators for stroke rehabilitation.

PubMed

Grube, Maike M; Dohle, Christian; Djouchadar, Diana; Rech, Petra; Bienek, Karen; Dietz-Fricke, Ursula; Jöbges, Michael; Kohler, Martin; Missala, Isabelle; Schönherr, Bertram; Werner, Cordula; Zeytountchian, Helen; Wissel, Jörg; Heuschmann, Peter U

2012-01-01

Previous stroke performance measures consider aspects of postacute treatment, but there are only few specific quality indicators or standards for poststroke rehabilitation. The purpose of this study was to develop a set of indicators for measuring the quality of postacute stroke rehabilitation in inpatient and outpatient facilities using a standardized evidence-based approach. Quality indicators were developed between January 2009 and February 2010 by an interdisciplinary board of healthcare professionals from rehabilitation centers cooperating in the Berlin Stroke Alliance. The Berlin Stroke Alliance is a regional network of >40 providers of acute treatment, rehabilitation, and aftercare aiming to improve stroke services within Berlin and Brandenburg. The indicators were developed according to published international recommendations and predefined methodological requirements. The applied standards included a systematic literature review, a rating of published evidence, an external peer review, and the evaluation in a pilot study before implementation. Of an initial list of 33 indicators, 20 indicators were rated as being appropriate. After completion of the pilot phase, we agreed on a set of 18 indicators. The indicators measure processes (9 indicators), outcomes (5 indicators), and structures (4 indicators) in the following domains of stroke rehabilitation: completion of diagnostics; secondary prevention; cognition and affect; speech and swallowing; management of complications; sensorimotor functions and mobility; discharge status; and aftercare. Documentation of evidence-based quality indicators for stroke rehabilitation in clinical routine is feasible and can serve as a first step toward implementing standardized cross-institutional quality assurance programs for stroke rehabilitation.

Allied health clinicians using translational research in action to develop a reliable stroke audit tool.

PubMed

Abery, Philip; Kuys, Suzanne; Lynch, Mary; Low Choy, Nancy

2018-05-23

To design and establish reliability of a local stroke audit tool by engaging allied health clinicians within a privately funded hospital. Design: Two-stage study involving a modified Delphi process to inform stroke audit tool development and inter-tester reliability. Allied health clinicians. A modified Delphi process to select stroke guideline recommendations for inclusion in the audit tool. Reliability study: 1 allied health representative from each discipline audited 10 clinical records with sequential admissions to acute and rehabilitation services. Recommendations were admitted to the audit tool when 70% agreement was reached, with 50% set as the reserve agreement. Inter-tester reliability was determined using intra-class correlation coefficients (ICCs) across 10 clinical records. Twenty-two participants (92% female, 50% physiotherapists, 17% occupational therapists) completed the modified Delphi process. Across 6 voting rounds, 8 recommendations reached 70% agreement and 2 reached 50% agreement. Two recommendations (nutrition/hydration; goal setting) were added to ensure representation for all disciplines. Substantial consistency across raters was established for the audit tool applied in acute stroke (ICC .71; range .48 to .90) and rehabilitation (ICC.78; range .60 to .93) services. Allied health clinicians within a privately funded hospital generally agreed in an audit process to develop a reliable stroke audit tool. Allied health clinicians agreed on stroke guideline recommendations to inform a stroke audit tool. The stroke audit tool demonstrated substantial consistency supporting future use for service development. This process, which engages local clinicians, could be adopted by other facilities to design reliable audit tools to identify local service gaps to inform changes to clinical practice. © 2018 John Wiley & Sons, Ltd.

Mapping patients' experiences after stroke onto a patient-focused intervention framework.

PubMed

Donnellan, C; Martins, A; Conlon, A; Coughlan, T; O'Neill, D; Collins, D R

2013-03-01

Stroke patients' involvement in the rehabilitation process including decision making has made significant advances clinically over the past two decades. However, development of patient-focused interventions in stroke rehabilitation is a relatively under developed area of research. The aim of this study was to interpret the explanations that patients gave of their experience after stroke and how these may validate an already established patient-focused intervention framework - the Quest for quality and improved performance (QQUIP) (2006) that includes seven quality improvement goals. A random purposive sample of eight stroke patients was interviewed between 3 and 6 months following discharge. Patients' reports of their experience after stroke were obtained using in-dept semi-structured interviews and analysed using Qualitative Content Analysis. Explanations given by patients included both positive and negative reports of the stroke experience. Regardless of consequences as a result of physical, psychological and social impairments, there were other life style disruptions that were reported by all patients such as taking new medication and adverse effects of these, experiencing increasing fatigue, difficulties with social activities and situations and having to make changes in health behaviours and lifestyle. Some of the core themes that emerged reflected the aims of QQUIP improvement goals that include improving health literacy, clinical decision-making, self-care, patient safety, access to health advice, care experience and service development. Further recommendations based on the findings from this study would be to consider using the QQUIP framework for developing intervention studies in stroke rehabilitation care that are person-centred. This framework provides a template that is equipped to address some of the main concerns that people have following the experience of stroke and also focuses on improving quality of care.

Serum Insulin-Like Growth Factor 1 and the Risk of Ischemic Stroke: The Framingham Study.

PubMed

Saber, Hamidreza; Himali, Jayandra J; Beiser, Alexa S; Shoamanesh, Ashkan; Pikula, Aleksandra; Roubenoff, Ronenn; Romero, Jose R; Kase, Carlos S; Vasan, Ramachandran S; Seshadri, Sudha

2017-07-01

Low insulin-like growth factor 1 (IGF-1) has been associated with increased risk of atherosclerosis and atrial fibrillation in cross-sectional studies. Yet, prospective data linking IGF-1 levels to the development of ischemic stroke remain inconclusive. We examined prospectively the association between serum IGF-1 levels and incident ischemic stroke. We measured serum IGF-1 levels in 757 elderly individuals (mean age 79±5, 62% women), free of prevalent stroke, from the Framingham original cohort participants at the 22nd examination cycle (1990-1994) and were followed up for the development of ischemic stroke. Cox models were used to relate IGF-1 levels to the risk for incident ischemic stroke, adjusted for potential confounders. During a mean follow-up of 10.2 years, 99 individuals developed ischemic stroke. After adjustment for age, sex, and potential confounders, higher IGF-1 levels were associated with a lower risk of incident ischemic stroke, with subjects in the lowest quintile of IGF-1 levels having a 2.3-fold higher risk of incident ischemic stroke (95% confidence interval, 1.09-5.06; P =0.03) as compared with those in the top quintile. We observed an effect modification by diabetes mellitus and waist-hip ratio for the association between IGF-1 and ischemic stroke ( P <0.1). In subgroup analyses, the effects were restricted to subjects with diabetics and those in top waist-hip ratio quartile, in whom each standard deviation increase in IGF-1 was associated with a 61% (hazard ratio, 0.39; 95% confidence interval, 0.20-0.78; P =0.007) and 41% (hazard ratio, 0.59; 95% confidence interval, 0.37-0.95; P =0.031) lower risk of incident ischemic stroke, respectively. IGF-1 levels were inversely associated with ischemic stroke, especially among persons with insulin resistance. © 2017 American Heart Association, Inc.

Randomized controlled trial of robot-assisted gait training with dorsiflexion assistance on chronic stroke patients wearing ankle-foot-orthosis.

PubMed

Yeung, Ling-Fung; Ockenfeld, Corinna; Pang, Man-Kit; Wai, Hon-Wah; Soo, Oi-Yan; Li, Sheung-Wai; Tong, Kai-Yu

2018-06-19

Robot-assisted ankle-foot-orthosis (AFO) can provide immediate powered ankle assistance in post-stroke gait training. Our research team has developed a novel lightweight portable robot-assisted AFO which is capable of detecting walking intentions using sensor feedback of wearer's gait pattern. This study aims to investigate the therapeutic effects of robot-assisted gait training with ankle dorsiflexion assistance. This was a double-blinded randomized controlled trial. Nineteen chronic stroke patients with motor impairment at ankle participated in 20-session robot-assisted gait training for about five weeks, with 30-min over-ground walking and stair ambulation practices. Robot-assisted AFO either provided active powered ankle assistance during swing phase in Robotic Group (n = 9), or torque impedance at ankle joint as passive AFO in Sham Group (n = 10). Functional assessments were performed before and after the 20-session gait training with 3-month Follow-up. Primary outcome measure was gait independency assessed by Functional Ambulatory Category (FAC). Secondary outcome measures were clinical scores including Fugl-Meyer Assessment (FMA), Modified Ashworth Scale (MAS), Berg Balance Scale (BBS), Timed 10-Meter Walk Test (10MWT), Six-minute Walk Test (SMWT), supplemented by gait analysis. All outcome measures were performed in unassisted gait after patients had taken off the robot-assisted AFO. Repeated-measures analysis of covariance was conducted to test the group differences referenced to clinical scores before training. After 20-session robot-assisted gait training with ankle dorsiflexion assistance, the active ankle assistance in Robotic Group induced changes in gait pattern with improved gait independency (all patients FAC ≥ 5 post-training and 3-month follow-up), motor recovery, walking speed, and greater confidence in affected side loading response (vertical ground reaction force + 1.49 N/kg, peak braking force + 0.24 N/kg) with heel strike instead of flat foot touch-down at initial contact (foot tilting + 1.91°). Sham Group reported reduction in affected leg range of motion (ankle dorsiflexion - 2.36° and knee flexion - 8.48°) during swing. Robot-assisted gait training with ankle dorsiflexion assistance could improve gait independency and help stroke patients developing confidence in weight acceptance, but future development of robot-assisted AFO should consider more lightweight and custom-fit design. ClinicalTrials.gov NCT02471248 . Registered 15 June 2015 retrospectively registered.

Aerodynamic forces and flow structures of the leading edge vortex on a flapping wing considering ground effect.

PubMed

Van Truong, Tien; Byun, Doyoung; Kim, Min Jun; Yoon, Kwang Joon; Park, Hoon Cheol

2013-09-01

The aim of this work is to provide an insight into the aerodynamic performance of the beetle during takeoff, which has been estimated in previous investigations. We employed a scaled-up electromechanical model flapping wing to measure the aerodynamic forces and the three-dimensional flow structures on the flapping wing. The ground effect on the unsteady forces and flow structures were also characterized. The dynamically scaled wing model could replicate the general stroke pattern of the beetle's hind wing kinematics during takeoff flight. Two wing kinematic models have been studied to examine the influences of wing kinematics on unsteady aerodynamic forces. In the first model, the angle of attack is asymmetric and varies during the translational motion, which is the flapping motion of the beetle's hind wing. In the second model, the angle of attack is constant during the translational motion. The instantaneous aerodynamic forces were measured for four strokes during the beetle's takeoff by the force sensor attached at the wing base. Flow visualization provided a general picture of the evolution of the three-dimensional leading edge vortex (LEV) on the beetle hind wing model. The LEV is stable during each stroke, and increases radically from the root to the tip, forming a leading-edge spiral vortex. The force measurement results show that the vertical force generated by the hind wing is large enough to lift the beetle. For the beetle hind wing kinematics, the total vertical force production increases 18.4% and 8.6% for the first and second strokes, respectively, due to the ground effect. However, for the model with a constant angle of attack during translation, the vertical force is reduced during the first stroke. During the third and fourth strokes, the ground effect is negligible for both wing kinematic patterns. This finding suggests that the beetle's flapping mechanism induces a ground effect that can efficiently lift its body from the ground during takeoff.

Feasibility and efficacy of wearable devices for upper limb rehabilitation in patients with chronic stroke: a randomized controlled pilot study.

PubMed

Lin, Li-Fong; Lin, Yi-Jia; Lin, Zi-Hao; Chuang, Li-Yun; Hsu, Wei-Chun; Lin, Yuan-Hsiang

2017-06-19

Wearable devices based on inertial measurement units through wireless sensor networks have many applications such as real-time motion monitoring and functional outcome assessment of stroke rehabilitation. However, additional investigations are warranted to validate their clinical value, particularly in detecting the synergy patterns of movements after stroke. To explore the feasibility and efficacy of wearable devices for upper limb rehabilitation in patients with chronic stroke and to compare the intervention effects (e.g., neurological recovery, active range of motion, and deviation angle) with those in a control group. A single-blind, randomized-controlled pilot study. Rehabilitation ward. A total of 18 patients with chronic stroke were randomly distributed into a device group and control group. Both groups received conventional rehabilitation; nevertheless, the device group was additionally subjected to 15 daily sessions at least three times a week for 5 weeks. The outcome measures included the upper extremity subscores of the Fugl-Meyer assessment, active range of motion, and deviation angle. These measurements were performed pre- and post-treatment. All five Fugl-Meyer assessment subscores improved in both the device and control groups after intervention; in particular, the "shoulder/elbow/forearm" subscore (p = 0.02, 0.03) and "total score" (p = 0.03, 0.03) substantially improved. The active range of motion of shoulder flexion and abduction substantially improved at pre-post treatment in both the device (p = 0.02, 0.03) and control (p = 0.02, 0.03) groups. The deviation angle of shoulder external rotation during shoulder abduction substantially improved in the device group (p = 0.02), but not in the control group. The designed wearable devices are practical and efficient for use in chronic patients with stroke. Wearable devices are expected to be useful for future internet-of-things rehabilitation clinical trials at home and in long-term care institutions.

Differences Between US and UK Adults in Stroke Preparedness

PubMed Central

Ford, Gary A.; Morgenstern, Lewis B.; White, Martin; Sniehotta, Falko F.; Mackintosh, Joan E.; Gellert, Paul; Skolarus, Lesli E.

2015-01-01

Background and Purpose— Although time-dependent treatment is available, most people delay contacting emergency medical services for stroke. Given differences in the healthcare system and public health campaigns, exploring between-country differences in stroke preparedness may identify novel ways to increase acute stroke treatment. Methods— A survey was mailed to population-based samples in Ingham County, Michigan, US (n=2500), and Newcastle upon Tyne, UK (n=2500). Surveys included stroke perceptions and stroke/nonstroke scenarios to assess recognition and response to stroke. Between-country differences and associations with stroke preparedness were examined using t tests and linear mixed models. Results— Overall response rate was 27.4%. The mean age of participants was 55 years, and 58% were female. US participants were better in recognizing stroke (70% versus 63%, d=0.27) and were more likely to call emergency medical services (55% versus 52%, d=0.11). After controlling for demographics and comorbidities, US participants remained more likely to recognize stroke but were not more likely to respond appropriately. A greater belief that medical treatment can help with stroke and understanding of stroke was associated with improved stroke recognition and response. Conclusions— Overall, stroke recognition and response were moderate. US participants were modestly better at recognizing stroke, although there was little difference in response to stroke. Future stroke awareness interventions could focus more on stroke outcome expectations and developing a greater understanding of stroke among the public. PMID:26419968

Treatment of hyperglycaemia in patients with acute stroke.

PubMed

Castilla-Guerra, L; Fernández-Moreno, M C; Hewitt, J

2016-03-01

The proportion of diabetic patients who are hospitalised for stroke has been increasing in recent years, currently reaching almost a third of all cases of stroke. In addition, about half of patients with acute stroke present hyperglycaemia in the first hours of the stroke. Although hyperglycaemia in the acute phase of stroke is associated with a poor prognosis, its treatment is currently a topic of debate. There is no evidence that the adminstration of intravenous insulin to these patients offers benefits in terms of the evolution of the stroke. New studies in development, such as the SHINE study (Stroke Hyperglycemia Insulin Network Effort), may contribute to clarifying the role of intensive control of glycaemia during the acute phase of the stroke. Ultimately, patients who have presented with stroke should be screened for diabetes. Copyright © 2015 Elsevier España, S.L.U. y Sociedad Española de Medicina Interna (SEMI). All rights reserved.

Advances in Probes and Methods for Clinical EPR Oximetry

PubMed Central

Hou, Huagang; Khan, Nadeem; Jarvis, Lesley A.; Chen, Eunice Y.; Williams, Benjamin B.; Kuppusamy, Periannan

2015-01-01

EPR oximetry, which enables reliable, accurate, and repeated measurements of the partial pressure of oxygen in tissues, provides a unique opportunity to investigate the role of oxygen in the pathogenesis and treatment of several diseases including cancer, stroke, and heart failure. Building on significant advances in the in vivo application of EPR oximetry for small animal models of disease, we are developing suitable probes and instrumentation required for use in human subjects. Our laboratory has established the feasibility of clinical EPR oximetry in cancer patients using India ink, the only material presently approved for clinical use. We now are developing the next generation of probes, which are both superior in terms of oxygen sensitivity and biocompatibility including an excellent safety profile for use in humans. Further advances include the development of implantable oxygen sensors linked to an external coupling loop for measurements of deep-tissue oxygenations at any depth, overcoming the current limitation of 10 mm. This paper presents an overview of recent developments in our ability to make meaningful measurements of oxygen partial pressures in human subjects under clinical settings. PMID:24729217

Linear Actuator Has Long Stroke and High Resolution

NASA Technical Reports Server (NTRS)

Cook, Brant T.; Moore, Donald M.; Braun, David F.; Koenig, John S.; Hankins, Steve M.

2009-01-01

The term precision linear actuator, direct drive ( PLADD ) refers to a robust linear actuator designed to be capable of repeatedly performing, over a lifetime of the order of 5 to 10 years, positioning maneuvers that include, variously, submicron increments or slews of the order of a centimeter. The PLADD is capable of both long stroke (120 mm) and high resolution (repeatable increments of 20 nm). Unlike precise linear actuators of prior design, the PLADD contains no gears, levers, or hydraulic converters. The PLADD, now at the prototype stage of development, is intended for original use as a coarse-positioning actuator in a spaceborne interferometer. The PLADD could also be adapted to terrestrial applications in which there are requirements for long stroke and high resolution: potential applications include medical imaging and fabrication of semiconductor devices. The PLADD (see figure) includes a commercially available ball-screw actuator driven directly by a commercially available three-phase brushless DC motor. The ball-screw actuator comprises a spring-preloaded ball nut on a ball screw that is restrained against rotation as described below. The motor is coupled directly (that is, without an intervening gear train) to a drive link that, in turn, is coupled to the ball nut. By eliminating the gear train, the direct-drive design eliminates the complexity, backlash, and potential for misalignment associated with a gear train. To prevent inadvertent movement, there is a brake that includes flexured levers compressed against the drive link by preload springs. This is a power-off brake: There are also piezoelectric stacks that can be activated to oppose the springs and push the levers away from the drive link. Hence, power must be applied to the piezoelectric stacks to release the drive link from braking. To help ensure long operational life, all of the mechanical drive components are immersed in an oil bath within hermetically sealed bellows. The outer end of the bellows holds the outer end of the ball screw, thereby preventing rotation of the ball screw. Positioning is controlled by an electronic control system that includes digital and analog subsystems that interact with the motor and brake and with two sensor/encoder units: a Hall-effect-sensor rotation encoder and a linear glass-scale encoder. This system implements a proportional + integral + derivative control algorithm that results in variation of voltage commands to each of the three pairs of windings of the brushless DC motor. In one of two alternative control modes, the voltages are applied to the windings in a trapezoidal commutation scheme on the basis of timing signals obtained from the Hall-effect sensors; this scheme yields relatively coarse positioning - 24 steps per motor revolution. The second control mode involves a sinusoidal commutation scheme in which the output of the linear glass-scale encoder is transposed to rotational increments to yield much finer position feedback - more than 400,000 steps per revolution.

Markedly impaired bilateral coordination of gait in post-stroke patients: Is this deficit distinct from asymmetry? A cohort study

PubMed Central

2011-01-01

Background Multiple aspects of gait are typically impaired post-stroke. Asymmetric gait is common as a consequence of unilateral brain lesions. The relationship between the resulting asymmetric gait and impairments in the ability to properly coordinate the reciprocal stepping activation of the legs is not clear. The objective of this exploratory study is to quantify the effects of hemiparesis on two putatively independent aspects of the bilateral coordination of gait to gain insight into mechanisms and their relationship and to assess their potential as clinical markers. Methods Twelve ambulatory stroke patients and age-matched healthy adults wore a tri-axial piezo-resistive accelerometer and walked back and forth along a straight path in a hall at a comfortable walking speed during 2 minutes. Gait speed, gait asymmetry (GA), and aspects of the bilateral coordination of gait (BCG) were determined. Bilateral coordination measures included the left-right stepping phase for each stride φi, consistency in the phase generation φ_CV, accuracy in the phase generation φ_ABS, and Phase Coordination Index (PCI), a combination of accuracy and consistency of the phase generation. Results Group differences (p < 0.001) were observed for gait speed (1.1 ± 0.1 versus 1.7 ± 0.1 m/sec for patients and controls, respectively), GA (26.3 ± 5.6 versus 5.5 ± 1.2, correspondingly) and PCI (19.5 ± 2.3 versus 6.2 ± 1.0, correspondingly). A significant correlation between GA and PCI was seen in the stroke patients (r = 0.94; p < 0.001), but not in the controls. Conclusions In ambulatory post-stroke patients, two gait coordination properties, GA and PCI, are markedly impaired. Although these features are not related to each other in healthy controls, they are strongly related in stroke patients, which is a novel finding. A measurement approach based on body-fixed sensors apparently may provide sensitive markers that can be used for clinical assessment and for enhancing rehabilitation targeting in post-stroke patients. PMID:21545703

In-hospital risk prediction for post-stroke depression: development and validation of the Post-stroke Depression Prediction Scale.

PubMed

de Man-van Ginkel, Janneke M; Hafsteinsdóttir, Thóra B; Lindeman, Eline; Ettema, Roelof G A; Grobbee, Diederick E; Schuurmans, Marieke J

2013-09-01

The timely detection of post-stroke depression is complicated by a decreasing length of hospital stay. Therefore, the Post-stroke Depression Prediction Scale was developed and validated. The Post-stroke Depression Prediction Scale is a clinical prediction model for the early identification of stroke patients at increased risk for post-stroke depression. The study included 410 consecutive stroke patients who were able to communicate adequately. Predictors were collected within the first week after stroke. Between 6 to 8 weeks after stroke, major depressive disorder was diagnosed using the Composite International Diagnostic Interview. Multivariable logistic regression models were fitted. A bootstrap-backward selection process resulted in a reduced model. Performance of the model was expressed by discrimination, calibration, and accuracy. The model included a medical history of depression or other psychiatric disorders, hypertension, angina pectoris, and the Barthel Index item dressing. The model had acceptable discrimination, based on an area under the receiver operating characteristic curve of 0.78 (0.72-0.85), and calibration (P value of the U-statistic, 0.96). Transforming the model to an easy-to-use risk-assessment table, the lowest risk category (sum score, <-10) showed a 2% risk of depression, which increased to 82% in the highest category (sum score, >21). The clinical prediction model enables clinicians to estimate the degree of the depression risk for an individual patient within the first week after stroke.

Cell-Based and Exosome Therapy in Diabetic Stroke.

PubMed

Venkat, Poornima; Chopp, Michael; Chen, Jieli

2018-03-02

Stroke is a global health concern and it is imperative that therapeutic strategies with wide treatment time frames be developed to improve neurological outcome in patients. Patients with diabetes mellitus who suffer a stroke have worse neurological outcomes and long-term functional recovery than nondiabetic stroke patients. Diabetes induced vascular damage and enhanced inflammatory milieu likely contributes to worse post stroke outcomes. Diabetic stroke patients have an aggravated pathological cascade, and treatments that benefit nondiabetic stroke patients do not necessarily translate to diabetic stroke patients. Therefore, there is a critical need to develop therapeutics for stroke specifically in the diabetic population. Stem cell based therapy for stroke is an emerging treatment option with wide therapeutic time window. Cell-based therapies for stroke promote endogenous central nervous system repair and neurorestorative mechanisms such as angiogenesis, neurogenesis, vascular remodeling, white matter remodeling, and also modulate inflammatory and immune responses at the local and systemic level. Emerging evidence suggests that exosomes and their cargo microRNA mediate cell therapy derived neurorestorative effects. Exosomes are small vesicles containing protein and RNA characteristic of its parent cell. Exosomes are transported by biological fluids and facilitate communication between neighboring and remote cells. MicroRNAs, a class of naturally occurring, small noncoding RNA sequences, contained within exosomes can regulate recipient cell's signaling pathways and alter protein expression either acting alone or in concert with other microRNAs. In this perspective article, we summarize current knowledge and highlight the promising future of cell based and exosome therapy for stroke and specifically for diabetic stroke. Stem Cells Translational Medicine 2018. © 2018 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

Real time and in vivo monitoring of nitric oxide by electrochemical sensors--from dream to reality.

PubMed

Zhang, Xueji

2004-09-01

Nitric oxide is a key intercellular messenger in the human and animal bodies. The identification of nitric oxide (NO) as the endothelium-derived relaxing factor (EDRF) has driven an enormous effort to further elucidate the chemistry, biology and therapeutic actions of this important molecule. It has found that nitric oxide is involved in many disease states such as such as chronic heart failure, stroke, impotent (erectile dysfunction). The bioactivity of nitric oxide intrinsically linked to its diffusion from its site production to the sites of action. Accurate reliable in real time detection of NO in various biological systems is therefore crucial to understanding its biological role. However, the instability of NO in aqueous solution and its high reactivity with other molecules can cause difficulties for its measurement depending on the detection method employed. Although a variety of methods have been described to measure NO in aqueous environments, it is now generally accepted that electrochemical (amperometric) detection using NO-specific electrodes is the most reliable and sensitive technique available for real-time in situ detection of NO. In 1992 the first commercial NO electrode-based amperometric detection system was developed by WPI. The system has been used successfully for a number of years in a wide range of research applications, both in vitro and in vivo. Recently, many new electrochemical nitric sensors have been invented and commercialized. Here we describe some of the background principles in NO sensors design, methodology and their applications.

Selection of NIR H2O absorption transitions for in-cylinder measurement of temperature in IC engines

NASA Astrophysics Data System (ADS)

Zhou, Xin; Liu, Xiang; Jeffries, Jay B.; Hanson, Ronald K.

2005-12-01

The water vapour spectrum in the 1.25-1.65 µm region is systematically analysed to find the best absorption transitions for sensitive measurement of in-cylinder gas temperature over short paths in an internal combustion engine. The strategy to select the optimum wavelength regions and absorption line combinations is developed for the time-varying pressures and temperatures expected during the compression portion of an engine cycle. We have identified 14 transitions of water vapour in this spectral region as promising for this application. From these transitions, 16 potential line pairs were considered for a wavelength-modulated absorption sensor for in-cylinder gas temperature during the compression stroke. Expected performance is modelled for the intake portion of two engine cycles that produce extreme temperature and pressure variations during compression.

Inertial Sensor Technology for Elite Swimming Performance Analysis: A Systematic Review

PubMed Central

Mooney, Robert; Corley, Gavin; Godfrey, Alan; Quinlan, Leo R; ÓLaighin, Gearóid

2015-01-01

Technical evaluation of swimming performance is an essential factor of elite athletic preparation. Novel methods of analysis, incorporating body worn inertial sensors (i.e., Microelectromechanical systems, or MEMS, accelerometers and gyroscopes), have received much attention recently from both research and commercial communities as an alternative to video-based approaches. This technology may allow for improved analysis of stroke mechanics, race performance and energy expenditure, as well as real-time feedback to the coach, potentially enabling more efficient, competitive and quantitative coaching. The aim of this paper is to provide a systematic review of the literature related to the use of inertial sensors for the technical analysis of swimming performance. This paper focuses on providing an evaluation of the accuracy of different feature detection algorithms described in the literature for the analysis of different phases of swimming, specifically starts, turns and free-swimming. The consequences associated with different sensor attachment locations are also considered for both single and multiple sensor configurations. Additional information such as this should help practitioners to select the most appropriate systems and methods for extracting the key performance related parameters that are important to them for analysing their swimmers’ performance and may serve to inform both applied and research practices. PMID:26712760

Recent Development of the Two-Stroke Engine. 2 - Design Features

DTIC Science & Technology

1945-05-01

NATIONALADVISORYCOMMI~EE FOR AERONAUTICS. TECHNICAL MEMORANDUM No, 1082 R~CENT DEVELOPMENT OX’ THE TWO–STROKE ENGTNE II - DES IGN l’llATURliS By J...MEMORANDUM . ... . ,., . ,.!. .,, .,- ... —--— — FOR AERONAUTICS ‘ NO. 1082 , > ,. RECENT DEVELOPMENT OF THE TWO-STROKE ENGINE II - DESIGN FEATURES* ,“” By...lUOTE: Reprint of R.T.P.3 Translation No. 2382; issued by the Ministry of Aircraft Production, London, England. II: ._: 2 NACA TM NO. 1082 (=“) The

Stroke Treatment Academic Industry Roundtable

PubMed Central

Jovin, Tudor G.; Albers, Gregory W.; Liebeskind, David S.

2017-01-01

Background and Purpose The STAIR (Stroke Treatment Academic Industry Roundtable) meeting aims to advance acute stroke therapy development through collaboration between academia, industry, and regulatory institutions. In pursuit of this goal and building on recently available level I evidence of benefit from endovascular therapy (ET) in large vessel occlusion stroke, STAIR IX consensus recommendations were developed that outline priorities for future research in ET. Methods Three key directions for advancing the field were identified: (1) development of systems of care for ET in large vessel occlusion stroke, (2) development of therapeutic approaches adjunctive to ET, and (3) exploring clinical benefit of ET in patient population insufficiently studied in recent trials. Methodological issues such as optimal trial design and outcome measures have also been addressed. Results Development of systems of care strategies should be geared both toward ensuring broad access to ET for eligible patients and toward shortening time to reperfusion to the minimum possible. Adjunctive therapy development includes neuroprotective approaches, adjuvant microcirculatory/collateral enhancing strategies, and periprocedural management. Future research priorities seeking to expand the eligible patient population are to determine benefit of ET in patients presenting beyond conventional time windows, in patients with large baseline ischemic core lesions, and in other important subgroups. Conclusions Research priorities in ET for large vessel occlusion stroke are to improve systems of care, investigate effective adjuvant therapies, and explore whether patient eligibility could be expanded. PMID:27586682

Development of a patient-centred, patient-reported outcome measure (PROM) for post-stroke cognitive rehabilitation: qualitative interviews with stroke survivors to inform design and content.

PubMed

Patchick, Emma L; Horne, Maria; Woodward-Nutt, Kate; Vail, Andy; Bowen, Audrey

2015-12-01

Improving cognition is service users' top research priority for life after stroke, and future research should include outcomes that they deem important. Patient perspectives on outcomes are collected using patient-reported outcome measures (PROMs). There is currently no patient-centred PROM specific for cognitive rehabilitation trials. Inform PROM development by exploring stroke survivor perspectives on the important, measurable impacts of persisting post-stroke cognitive problems. Qualitative semi-structured interviews in participants' homes. Purposive sample of 16 cognitively impaired stroke survivors at least six months post-stroke. Interviews used a schedule and communication aids developed through patient consultation. Interviews were transcribed verbatim with non-verbal communication recorded using field notes. Data were analysed using a framework approach to find commonalities to shape the focus and content of an outcome measure. Participants identified important impacts of their 'invisible' cognitive problems, outside of other stroke-related impairments. Cognitive problems exacerbated emotional issues and vice versa. Changes in self-identity and social participation were prominent. Impact was not spoken about in terms of frequency but rather in terms of the negative affect associated with problems; terms like 'bothered' and 'frustration' were often used. The results support the development of a PROM specifically designed to address the impact of cognitive problems. It should: include items addressing a comprehensive range of cognitive skills; ask questions about mood, self-identity and social participation; use accessible wording that respondents understand and endorse; measure impact rather than frequency; and explore perceived impact on carers. © 2014 John Wiley & Sons Ltd.

Frequency-difference MIT imaging of cerebral haemorrhage with a hemispherical coil array: numerical modelling.

PubMed

Zolgharni, M; Griffiths, H; Ledger, P D

2010-08-01

The feasibility of detecting a cerebral haemorrhage with a hemispherical MIT coil array consisting of 56 exciter/sensor coils of 10 mm radius and operating at 1 and 10 MHz was investigated. A finite difference method combined with an anatomically realistic head model comprising 12 tissue types was used to simulate the strokes. Frequency-difference images were reconstructed from the modelled data with different levels of the added phase noise and two types of a priori boundary errors: a displacement of the head and a size scaling error. The results revealed that a noise level of 3 m degrees (standard deviation) was adequate for obtaining good visualization of a peripheral stroke (volume approximately 49 ml). The simulations further showed that the displacement error had to be within 3-4 mm and the scaling error within 3-4% so as not to cause unacceptably large artefacts on the images.

Changes in intracranial pressure gradients between the cerebral hemispheres in patients with intracerebral hematomas in one cerebral hemisphere.

PubMed

Qiu, Wusi; Jiang, Qizhou; Xiao, Guoming; Wang, Weiming; Shen, Hong

2014-01-01

Intracranial-pressure (ICP) monitoring is useful for patients with increased ICP following hemorrhagic stroke. In this study, the changes in pressure gradients between the two cerebral hemispheres were investigated after hemorrhagic stroke of one side, and after a craniotomy. Twenty-four patients with acute cerebral hemorrhages and intracerebral hematomas who exhibited mass effect and midline shift to the contralateral side on computed tomography were selected for this study. After admission, both sides of the cranium were drilled, and optical fiber sensors were implanted to monitor the brain parenchyma pressure (BPP) in both cerebral hemispheres. All patients underwent surgical hematoma evacuations. The preoperative and postoperative BPP data from both cerebral hemispheres were collected at various time points and compared pairwise. There were statistically significant differences (P < 0.01) in the preoperative BPP values between the two hemispheres at three different time points. Differences in the BPP values between the two hemispheres at the time of surgery, and 24 and 48 h after surgery, were not statistically significant (P > 0.05). The posteroperative BPPs of both hemispheres were statistically significantly lower than preoperative recordings. BPP sensors should be applied to the injured cerebral hemisphere, because this becomes the source of increased ICP. Hematoma evacuation surgery effectively decreases ICP and eliminates pressure gradients between the two cerebral hemispheres, consequently enabling brain shift correction.

Incidence and 30-day case fatality rate of first-ever stroke in urban Nigeria: the prospective community based Epidemiology of Stroke in Lagos (EPISIL) phase II results.

PubMed

Danesi, Mustapha A; Okubadejo, Njideka U; Ojini, Frank I; Ojo, Oluwadamilola O

2013-08-15

Stroke is a leading cause of death worldwide and a major contributor to global disease burden. Although epidemiologic information from a community perspective is important in determining the magnitude of the burden in specific regions, and directing equitable distribution of health resources, data on the incidence of stroke in developing countries in Africa are scarce. To determine the current incidence rate and short-term (30-day) case fatality rate (CFR) of stroke in urban Nigeria, and provide age-adjusted and gender-specific incidence rates to enable comparison with global populations. The study was a prospective community-based stroke registry enrolling hospitalized and non-hospitalized first-ever in a lifetime stroke cases presenting at all health facilities (hospitals, homeopathic caregivers, physiotherapy clinics) located in the designated community. Pre-hospitalization deaths due to stroke were not included in our study. The study was conducted between January 1st and December 31st 2007 in Surulere Local Government Area of Lagos State, south western Nigeria, a mixed-income urban locality with a population of approximately 750,000 based on data from the National Population Commission. Stroke was defined using the World Health Organization (WHO) clinical criteria. Case fatality at 30-days post stroke was determined at follow-up on 160 hospitalized stroke cases. 189 first-ever strokes, comprised of 112 men and 77 women (mean±SD age 58.5±13.5 years) were documented, giving a crude incidence rate of 25.2 per 100,000 per year (95% confidence interval 21.6- 28.8). The gender-specific rates were 28.3/100,000 and 21.3/100,000 for males and females respectively. The age-adjusted incidence rate was 54.08 per 100,000 per year (adjusted to the WHO New World Population). Hospitalization rate was 84.6%, while the CFR (hospitalized) was 16.2%. The stroke incidence in this urban sub-Saharan African community remains lower than that in emerging and developed economies, although the age- and gender-related trends and CFR are comparable to that in developed countries. Copyright © 2013 Elsevier B.V. All rights reserved.

Development of stroke-induced quadriplegia after endovascular repair of blunt aortic injury pseudoaneurysm.

PubMed

Amoudi, Abdullah S; Merdad, Anas A; Makhdoom, Ahmed Q; Jamjoom, Reda A

2015-01-01

Endovascular repair of blunt aortic injury is now a first-line approach in management. This can warrant coverage of the left subclavian artery (LSA), which could lead to posterior strokes. In this case report, we present a severe complication of endovascular repair of a traumatic aortic aneurysm. A 53-year-old man presented with blunt aortic injury, endovascular repair was carried out where the left subclavian artery was covered. The intervention had a 100% technical success. Twelve hours later, he was discovered to have quadriplegia, a CT scan showed a large left cerebellar infarction extending to the medulla oblongata and proximal spinal cord. Strokes complicate 3% of thoracic endovascular aortic repairs, 80% of those strokes occur in patients who had their LSA`s covered. Most patients however, tolerate the coverage. Although our patient had a dominant right vertebral artery, and lacked risks for these strokes, he developed an extensive stroke that left him quadriplegic.

Development and evaluation of a Smartphone-enabled, caregiver-supported educational intervention for management of physical disabilities following stroke in India: protocol for a formative research study

PubMed Central

Sureshkumar, K; Murthy, G V S; Kinra, Sanjay; Goenka, Shifalika; Kuper, Hannah

2015-01-01

The incidence and prevalence of stroke in India has reached epidemic proportions. The growing magnitude of disability in patients with stroke in India poses a major public health challenge. Given the nature of the condition, affected individuals often become disabled with profound effects on their quality of life. The availability of rehabilitation services for people with disabilities is inadequate in India. Rehabilitation services are usually offered by private hospitals located in urban areas and many stroke survivors, especially those who are poor or live in rural areas, cannot afford to pay for, or do not have access to, such services. Thus, identification of cost-effective ways to rehabilitate people with stroke-related disability is an important challenge. Educational interventions in stroke rehabilitation can assist stroke survivors to make informed decisions regarding their on-going treatment and to self-manage their condition with support from their caregivers. Although educational interventions have been shown to improve patient knowledge for self-management of stroke, an optimal format for the intervention has not as yet been established, particularly in low- and middle-income countries. This formative research study aims to systematically develop an educational intervention for management of post-stroke disability for stroke survivors in India, and evaluate the feasibility and acceptability of delivering the intervention using Smartphones and with caregiver support. The research study will be conducted in Chennai, India, and will be organised in three different phases. Phase 1: Development of the intervention. Phase 2: Field testing and finalising the intervention. Phase 3: Piloting of the intervention and assessment of feasibility and acceptability. A mixed-methods approach will be used to develop and evaluate the intervention. If successful, it will help realise the potential of using Smartphone-enabled, carer-supported educational intervention to bridge the gaps in service access for rehabilitation of individuals with stroke-related disability in India. The proposed research will also provide valuable information for clinicians and policymakers. PMID:26751379

External validation of a six simple variable model of stroke outcome and verification in hyper-acute stroke.

PubMed

Reid, J M; Gubitz, G J; Dai, D; Reidy, Y; Christian, C; Counsell, C; Dennis, M; Phillips, S J

2007-12-01

We aimed to validate a previously described six simple variable (SSV) model that was developed from acute and sub-acute stroke patients in our population that included hyper-acute stroke patients. A Stroke Outcome Study enrolled patients from 2001 to 2002. Functional status was assessed at 6 months using the modified Rankin Scale (mRS). SSV model performance was tested in our cohort. 538 acute ischaemic (87%) and haemorrhagic stroke patients were enrolled, 51% of whom presented to hospital within 6 h of symptom recognition. At 6 months post-stroke, 42% of patients had a good outcome (mRS < or = 2). Stroke patients presenting within 6 h of symptom recognition were significantly older with higher stroke severity. In our Stroke Outcome Study dataset, the SSV model had an area under the curve of 0.792 for 6 month outcomes and performed well for hyper-acute or post-acute stroke, age < or > or = 75 years, haemorrhagic or ischaemic stroke, men or women, moderate and severe stroke, but poorly for mild stroke. This study confirms the external validity of the SSV model in our hospital stroke population. This model can therefore be utilised for stratification in acute and hyper-acute stroke trials.

Assessment of isometric muscle strength and rate of torque development with hand-held dynamometry: Test-retest reliability and relationship with gait velocity after stroke.

PubMed

Mentiplay, Benjamin F; Tan, Dawn; Williams, Gavin; Adair, Brooke; Pua, Yong-Hao; Bower, Kelly J; Clark, Ross A

2018-04-27

Isometric rate of torque development examines how quickly force can be exerted and may resemble everyday task demands more closely than isometric strength. Rate of torque development may provide further insight into the relationship between muscle function and gait following stroke. Aims of this study were to examine the test-retest reliability of hand-held dynamometry to measure isometric rate of torque development following stroke, to examine associations between strength and rate of torque development, and to compare the relationships of strength and rate of torque development to gait velocity. Sixty-three post-stroke adults participated (60 years, 34 male). Gait velocity was assessed using the fast-paced 10 m walk test. Isometric strength and rate of torque development of seven lower-limb muscle groups were assessed with hand-held dynamometry. Intraclass correlation coefficients were calculated for reliability and Spearman's rho correlations were calculated for associations. Regression analyses using partial F-tests were used to compare strength and rate of torque development in their relationship with gait velocity. Good to excellent reliability was shown for strength and rate of torque development (0.82-0.97). Strong associations were found between strength and rate of torque development (0.71-0.94). Despite high correlations between strength and rate of torque development, rate of torque development failed to provide significant value to regression models that already contained strength. Assessment of isometric rate of torque development with hand-held dynamometry is reliable following stroke, however isometric strength demonstrated greater relationships with gait velocity. Further research should examine the relationship between dynamic measures of muscle strength/torque and gait after stroke. Copyright © 2018 Elsevier Ltd. All rights reserved.

Sensitivity and Specificity of an Adult Stroke Screening Tool in Childhood Ischemic Stroke.

PubMed

Neville, Kerri; Lo, Warren

2016-05-01

There are frequent delays in the diagnosis of acute pediatric ischemic stroke. A screening tool that could increase the suspicion of acute ischemic stroke could aid early recognition and might improve initial care. An earlier study reported that children with acute ischemic stroke have signs that can be recognized with two adult stroke scales. We tested the hypothesis that an adult stroke scale could distinguish children with acute ischemic stroke from children with acute focal neurological deficits not due to stroke. We retrospectively applied an adult stroke scale to the recorded examinations of 53 children with acute symptomatic acute ischemic stroke and 53 age-matched control subjects who presented with focal neurological deficits. We examined the sensitivity and specificity of the stroke scale and the occurrence of acute seizures as predictors of stroke status. The total stroke scale did not differentiate children with acute ischemic stroke from those who had acute deficits from nonstroke causes; however, the presence of arm weakness was significantly associated with stroke cases. Acute seizures were significantly associated with stroke cases. An adult stroke scale is not sensitive or specific to distinguish children with acute ischemic stroke from those with nonstroke focal neurological deficits. The development of a pediatric acute ischemic stroke screening tool should include arm weakness and perhaps acute seizures as core elements. Such a scale must account for the limitations of language in young or intellectually disabled children. Copyright © 2016 Elsevier Inc. All rights reserved.

Improving human activity recognition and its application in early stroke diagnosis.

PubMed

Villar, José R; González, Silvia; Sedano, Javier; Chira, Camelia; Trejo-Gabriel-Galan, Jose M

2015-06-01

The development of efficient stroke-detection methods is of significant importance in today's society due to the effects and impact of stroke on health and economy worldwide. This study focuses on Human Activity Recognition (HAR), which is a key component in developing an early stroke-diagnosis tool. An overview of the proposed global approach able to discriminate normal resting from stroke-related paralysis is detailed. The main contributions include an extension of the Genetic Fuzzy Finite State Machine (GFFSM) method and a new hybrid feature selection (FS) algorithm involving Principal Component Analysis (PCA) and a voting scheme putting the cross-validation results together. Experimental results show that the proposed approach is a well-performing HAR tool that can be successfully embedded in devices.

Self-reported history of stroke and long-term living conditions near air pollution sources: results of a national epidemiological study in Lebanon.

PubMed

Salameh, Pascale; Farah, Rita; Hallit, Souheil; Zeidan, Rouba Karen; Chahine, Mirna N; Asmar, Roland; Hosseini, Hassan

2018-02-20

Stroke is a disease related to high mortality and morbidity, particularly in developing countries. Some studies have linked self-reported indoor and outdoor pollution to stroke and mini-stroke, while some others showed no association. Our objective was to assess this association in Lebanon, a Middle Eastern developing country. A national cross-sectional study was conducted all over Lebanon. In addition to self-reported items of pollution exposure, we assessed potential predictors of stroke and mini-stroke, including sociodemographic characteristics, self-reported health information, and biological measurements. Moreover, we assessed dose-effect relationship of pollution items in relation with stroke. Self-reported indoor pollution exposure was associated with stroke and mini-stroke, with or without taking biological values into account. Moreover, we found a dose-effect relationship of exposure with risk of disease, but this effect did not reach statistical significance after adjustment for sociodemographics and biological characteristics. No association was found for any outdoor pollution item. Although additional studies would be necessary to confirm these findings, sensitizing the population about the effect of pollution on chronic diseases, working on reducing pollution, and improving air quality should be implemented to decrease the burden of the disease on the population and health system.

STANDARDIZING THE STRUCTURE OF STROKE CLINICAL AND EPIDEMIOLOGIC RESEARCH DATA: THE NINDS STROKE COMMON DATA ELEMENT (CDE) PROJECT

PubMed Central

Saver, Jeffrey L.; Warach, Steven; Janis, Scott; Odenkirchen, Joanne; Becker, Kyra; Benavente, Oscar; Broderick, Joseph; Dromerick, Alexander W.; Duncan, Pamela; Elkind, Mitchell S. V.; Johnston, Karen; Kidwell, Chelsea S.; Meschia, James F.; Schwamm, Lee

2012-01-01

Background and Purpose The National Institute of Neurological Disorders and Stroke initiated development of stroke-specific Common Data Elements (CDEs) as part of a project to develop data standards for funded clinical research in all fields of neuroscience. Standardizing data elements in translational, clinical and population research in cerebrovascular disease could decrease study start-up time, facilitate data sharing, and promote well-informed clinical practice guidelines. Methods A Working Group of diverse experts in cerebrovascular clinical trials, epidemiology, and biostatistics met regularly to develop a set of Stroke CDEs, selecting among, refining, and adding to existing, field-tested data elements from national registries and funded trials and studies. Candidate elements were revised based on comments from leading national and international neurovascular research organizations and the public. Results The first iteration of the NINDS stroke-specific CDEs comprises 980 data elements spanning nine content areas: 1) Biospecimens and Biomarkers; 2) Hospital Course and Acute Therapies; 3) Imaging; 4) Laboratory Tests and Vital Signs; 5) Long Term Therapies; 6) Medical History and Prior Health Status; 7) Outcomes and Endpoints; 8) Stroke Presentation; 9) Stroke Types and Subtypes. A CDE website provides uniform names and structures for each element, a data dictionary, and template case report forms (CRFs) using the CDEs. Conclusion Stroke-specific CDEs are now available as standardized, scientifically-vetted variable structures to facilitate data collection and data sharing in cerebrovascular patient-oriented research. The CDEs are an evolving resource that will be iteratively improved based on investigator use, new technologies, and emerging concepts and research findings. PMID:22308239

Organization of acute stroke services in Poland - Polish Stroke Unit Network development.

PubMed

Sarzyńska-Długosz, Iwona; Skowrońska, Marta; Członkowska, Anna

2013-01-01

According to the recommendations of stroke organizations, every stroke patient should be treated in a specialized stroke unit (SU). We aimed to evaluate the development of the SU network in Poland during the past decade. In Poland, stroke is treated mainly by neurologists. A questionnaire evaluating structure and staff of neurological departments was sent to all neurological departments in 2003, 2005 and 2007. In 2010, we collected data based on information from the National Health Fund. We divided departments into categories: with a comprehensive SU, with a primary SU unit, and departments without an SU. Primary SUs were further divided into class A SUs (fulfilling criteria of the National Programme of Prevention and Treatment of Stroke Experts - eligible for thrombolysis), class B (conditionally fulfilling criteria), and class C (not fulfilling criteria). Final analyses included 87.4% of departments (194/222) in 2003, 85.5% of departments (188/220) in 2005, and 83.1% of departments (182/219) in 2007. According to the above-mentioned classification there were 20 class A SUs in 2003, 58 in 2005 and 5 comprehensive and 51 class A SUs in 2007. In 2012, based on information from the National Health Fund there were 150 SUs, all fulfilling criteria for thrombolysis, 9 of them comprehensive SUs. The SU network in Poland is developing dynamically but thrombolysis and endovascular procedures are done too rarely. Now it is necessary to improve quality of stroke services and to make organizational changes in the in-hospital stroke pathways as well as to organize continuous education of medical staff.

Correcting highly aberrated eyes using large-stroke adaptive optics.

PubMed

Sabesan, Ramkumar; Ahmad, Kamran; Yoon, Geunyoung

2007-11-01

To investigate the optical performance of a large-stroke deformable mirror in correcting large aberrations in highly aberrated eyes. A large-stroke deformable mirror (Mirao 52D; Imagine Eyes) and a Shack-Hartmann wavefront sensor were used in an adaptive optics system. Closed-loop correction of the static aberrations of a phase plate designed for an advanced keratoconic eye was performed for a 6-mm pupil. The same adaptive optics system was also used to correct the aberrations in one eye each of two moderate keratoconic and three normal human eyes for a 6-mm pupil. With closed-loop correction of the phase plate, the total root-mean-square (RMS) over a 6-mm pupil was reduced from 3.54 to 0.04 microm in 30 to 40 iterations, corresponding to 3 to 4 seconds. Adaptive optics closed-loop correction reduced an average total RMS of 1.73+/-0.998 to 0.10+/-0.017 microm (higher order RMS of 0.39+/-0.124 to 0.06+/-0.004 microm) in the three normal eyes and 2.73+/-1.754 to 0.10+/-0.001 microm (higher order RMS of 1.82+/-1.058 to 0.05+/-0.017 microm) in the two keratoconic eyes. Aberrations in both normal and highly aberrated eyes were successfully corrected using the large-stroke deformable mirror to provide almost perfect optical quality. This mirror can be a powerful tool to assess the limit of visual performance achievable after correcting the aberrations, especially in eyes with abnormal corneal profiles.

[Commercial video games in the rehabilitation of patients with sub-acute stroke: a pilot study].

PubMed

Cano-Manas, M J; Collado-Vazquez, S; Cano-de-la-Cuerda, R

2017-10-16

Stroke generates dependence on the patients due to the various impairments associated. The use of low-cost technologies for neurological rehabilitation may be beneficial for the treatment of these patients. To determine whether combined treatment using a semi-immersive virtual reality protocol to an interdisciplinary rehabilitation approach, improve balance and postural control, functional independence, quality of life, motivation, self-esteem and adherence to intervention in stroke patients in subacute stage. A longitudinal prospective study with pre and post-intervention evaluation was carried out. Fourteen were recruited at La Fuenfria Hospital (Spain) and completed the intervention. Experimental intervention was performed during eight weeks in combination with conventional treatment of physiotherapy and occupational therapy. Each session was increased in time and intensity, using commercial video games linked to Xbox 360° videoconsole and Kinect sensor. There were statistical significant improvements in modified Rankin scale (p = 0.04), baropodometry (load distribution, p = 0.03; support surface, p = 0.01), Barthel Index (p = 0.01), EQ-5D Questionnaire (p = 0.01), motivation (p = 0.02), self-esteem (p = 0.01) and adherence to the intervention (p = 0.02). An interdisciplinary rehabilitation approach supplemented with semi-immersive virtual reality seems to be useful for improving balance and postural control, functional independence in basic activities of daily living, quality of life, as well as motivation and self-esteem, with excellent adherence. This intervention modality could be adopted as a therapeutic tool in neurological rehabilitation of stroke patients in subacute stage.

Propulsion System with Pneumatic Artificial Muscles for Powering Ankle-Foot Orthosis

NASA Astrophysics Data System (ADS)

Veneva, Ivanka; Vanderborght, Bram; Lefeber, Dirk; Cherelle, Pierre

2013-12-01

The aim of this paper is to present the design of device for control of new propulsion system with pneumatic artificial muscles. The propulsion system can be used for ankle joint articulation, for assisting and rehabilitation in cases of injured ankle-foot complex, stroke patients or elderly with functional weakness. Proposed device for control is composed by microcontroller, generator for muscles contractions and sensor system. The microcontroller receives the control signals from sensors and modulates ankle joint flex- ion and extension during human motion. The local joint control with a PID (Proportional-Integral Derivative) position feedback directly calculates desired pressure levels and dictates the necessary contractions. The main goal is to achieve an adaptation of the system and provide the necessary joint torque using position control with feedback.

Demystifying post-stroke pain: from etiology to treatment

PubMed Central

Treister, Andrew K.; Hatch, Maya N.; Cramer, Steven C.; Chang, Eric Y.

2016-01-01

Pain following stroke is commonly reported but often incompletely managed, which prevents optimal recovery. This is in part due to the esoteric nature of post-stroke pain and its limited presence in current discussions of stroke management. The major specific afflictions that affect patients with stroke who develop pain include central post-stroke pain (CPSP), complex regional pain syndrome (CRPS), and pain associated with spasticity and shoulder subluxation. Each disorder carries its own intricacies that require specific approaches to treatment and understanding. This review aims to present and clarify the major pain syndromes that affect patients who have suffered from stroke in order to aid in their diagnosis and treatment. PMID:27317916

Strategy of thunderstorm measurement with super dense ground-based observation network

NASA Astrophysics Data System (ADS)

Takahashi, Y.; Sato, M.

2014-12-01

It's not easy to understand the inside structure and developing process of thunderstorm only with existing meteorological instruments since its horizontal extent of the storm cell is sometimes smaller than an order of 10 km while one of the densest ground network in Japan, AMEDAS, consists of sites located every 17 km in average and the resolution of meteorological radar is 1-2 km in general. Even the X-band radar realizes the resolution of 250 m or larger. Here we suggest a new super dense observation network with simple and low cost sensors that can be used for measurement both of raindrop and vertical electric field change caused by cloud-to-ground lightning discharge. This sensor consists of two aluminum plates with a diameter of 10-20 cm. We carried out an observation campaign in summer of 2013 in the foothills of Mt. Yastugatake, Yamanashi and Nagano prefectures in Japan, installing 6 plate-type sensors at a distance of about 4 km. Horizontal location, height and charge amount of each lightning discharge are estimated successfully based on the information of electric field changes at several observing sites. Moreover, it was found that the thunderstorm has a very narrow structure well smaller than 300 m that cannot be measured by any other ways, counting the positive and negative pulses caused by attachment of raindrop to the sensor plate, respectively. We plan to construct a new super dense observation network in the north Kanto region, Japan, where the lightning activity is most prominent in summer Japan, distributing more than several tens of sensors at every 4 km or shorter, such as an order of 100 m at minimum. This kind of new type network will reveal the unknown fine structures of thunderstorms and open the door for constructing real time alert system of torrential rainfall and lightning stroke especially in the city area.

Dry Electrodes for ECG and Pulse Transit Time for Blood Pressure: A Wearable Sensor and Smartphone Communication Approach

NASA Astrophysics Data System (ADS)

Shyamkumar, Prashanth

Cardiovascular Diseases (CVDs) have been a major cause for deaths in both men and women in United States. Cerebrovascular Diseases like Strokes are known to have origins in CVDs as well. Moreover, nearly 18 Million Americans have a history of myocardial infarction and are currently undergoing cardiac rehabilitation. Consequently, CVDs are the highest costing disease groups and cost more than all types of cancer combined. However, significant cost reduction is possible through the effective use of the vast advances in embedded and pervasive electronic devices for healthcare. These devices can automate and move a significant portion of disease management to the patient's home through cyber connectivity, a concept known as point-of-care (POC) diagnostics and healthcare services. POC can minimize hospital visits and potentially avoid admission altogether with prognostic tools that give advanced notice of any abnormalities or chronic illnesses so that the treatment can be planned in advance. The POC concept requires continuous remote health monitoring. Therefore, the various sensors needed for comprehensive monitoring need to be worn daily and throughout the day. Moreover, true "roaming" capability is necessary so that it does not restrict the user's travel or his/her quotidian activities. Two biomedical signals namely, Electrocardiogram (ECG) and Blood Pressure are important diagnostic tests in assessing the cardiac health of a person. To that end, the research presented in this thesis: First , describes the development of a remote monitoring solution based on Bluetooth(TM), smartphones and cyber infrastructure for cardiac care called e-nanoflex. Second, Sensors for ECG that are compatible with everyday life style namely, (a) dry, gel-less vertically aligned gold nanowire electrodes, (b) dry textile-based conductive sensor electrodes to address the need for this technology to monitor cardiovascular diseases in women are tested with e-nanoflex and discussed. Third, non-invasive, cuff-less Blood pressure estimation based on Pulse Transit Time with multiple synchronized sensor nodes, is implemented with e-nanoflex and the results are discussed.

Development and validation of clinical prediction models for mortality, functional outcome and cognitive impairment after stroke: a study protocol.

PubMed

Fahey, Marion; Rudd, Anthony; Béjot, Yannick; Wolfe, Charles; Douiri, Abdel

2017-08-18

Stroke is a leading cause of adult disability and death worldwide. The neurological impairments associated with stroke prevent patients from performing basic daily activities and have enormous impact on families and caregivers. Practical and accurate tools to assist in predicting outcome after stroke at patient level can provide significant aid for patient management. Furthermore, prediction models of this kind can be useful for clinical research, health economics, policymaking and clinical decision support. 2869 patients with first-ever stroke from South London Stroke Register (SLSR) (1995-2004) will be included in the development cohort. We will use information captured after baseline to construct multilevel models and a Cox proportional hazard model to predict cognitive impairment, functional outcome and mortality up to 5 years after stroke. Repeated random subsampling validation (Monte Carlo cross-validation) will be evaluated in model development. Data from participants recruited to the stroke register (2005-2014) will be used for temporal validation of the models. Data from participants recruited to the Dijon Stroke Register (1985-2015) will be used for external validation. Discrimination, calibration and clinical utility of the models will be presented. Patients, or for patients who cannot consent their relatives, gave written informed consent to participate in stroke-related studies within the SLSR. The SLSR design was approved by the ethics committees of Guy's and St Thomas' NHS Foundation Trust, Kings College Hospital, Queens Square and Westminster Hospitals (London). The Dijon Stroke Registry was approved by the Comité National des Registres and the InVS and has authorisation of the Commission Nationale de l'Informatique et des Libertés. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Scientific Lightning Detection Network for Kazakhstan

NASA Astrophysics Data System (ADS)

Streltsov, A. V.; Lozbin, A.; Inchin, A.; Shpadi, Y.; Inchin, P.; Shpadi, M.; Ayazbayev, G.; Bykayev, R.; Mailibayeva, L.

2015-12-01

In the frame of grant financing of the scientific research in 2015-2017 the project "To Develop Electromagnetic System for lightning location and atmosphere-lithosphere coupling research" was found. The project was start in January, 2015 and should be done during 3 years. The purpose is to create a system of electromagnetic measurements for lightning location and atmosphere-lithosphere coupling research consisting of a network of electric and magnetic sensors and the dedicated complex for data processing and transfer to the end user. The main tasks are to set several points for electromagnetic measurements with 100-200 km distance between them, to develop equipment for these points, to develop the techniques and software for lightning location (Time-of-arrival and Direction Finding (TOA+DF)) and provide a lightning activity research in North Tien-Shan region with respect to seismicity and other natural and manmade activities. Also, it is planned to use lightning data for Global Electric Circuit (GEC) investigation. Currently, there are lightning detection networks in many countries. In Kazakhstan we have only separate units in airports. So, we don't have full lightning information for our region. It is planned, to setup 8-10 measurement points with magnetic and electric filed antennas for VLF range. The final data set should be including each stroke location, time, type (CG+, CG-, CC+ or CC-) and waveform from each station. As the magnetic field lightning antenna the ferrite rod VLF antenna will be used. As the electric field antenna the wide range antenna with specific frequencies filters will be used. For true event detection TOA and DF methods needs detected stroke from minimum 4 stations. In this case we can get location accuracy about 2-3 km and better.

New portable voice guidance device for the manual wheelchair transfer: a pilot study in patients with hemiplegia.

PubMed

Yoshida, Taiki; Otaka, Yohei; Osu, Rieko; Kita, Kahori; Sakata, Sachiko; Kondo, Kunitsugu

2017-05-01

Older and/or cognitively impaired patients require verbal guidance to prevent accidents during wheelchair operation, thus increasing the burden on caregivers. This study aimed to develop a new portable voice guidance device for manual wheelchairs and examine its clinical usefulness. We developed a portable voice guidance device to monitor the statuses of wheelchair brakes and footrests and automatically provide voice guidance for operation. The device comprises a microcomputer, four magnets and magnetic sensors, speaker and battery. Device operation was assessed during the transfer from a wheelchair to bed six times per day over three days for a total of 90 transfers in five stroke patients (mean age: 79.6 years) who required verbal guidance to direct wheelchair operation. Device usability was also assessed using a questionnaire. The device performed perfectly during all attempted transfers (100%). To ensure safety, the assessor needed to add verbal guidance during 33 of 90 attempted transfers (36.6%). Overall, the device usability was favourable. However, some assessors were unsatisfied with the volume of the device voice, guidance timing and burden reduction. Our device could facilitate wheelchair operation and might potentially be used to reduce fall risk in stroke patients and the burden on caregivers. Implications for Rehabilitation The acquisition of transfer independence is an important step in the rehabilitation of patients with mobility issues. Many patients require supervision and guidance regarding the operation of brakes and footrests on manual wheelchairs. This newly developed voice guidance device for manual wheelchair transfers worked well in patients with hemiplegia and might be helpful to reduce the fall risks and the burden of care.

Recovery of Dysphagia in Lateral Medullary Stroke

PubMed Central

Gupta, Hitesh; Banerjee, Alakananda

2014-01-01

Lateral medullary stroke is typically associated with increased likelihood of occurrence of dysphagia and exhibits the most severe and persistent form. Worldwide little research exists on dysphagia in brainstem stroke. An estimated 15% of all patients admitted to stroke rehabilitation units experience a brainstem stroke out of which about 47% suffer from dysphagia. In India, a study showed that 22.3% of posterior circulation stroke patients develop dysphagia. Dearth of literature on dysphagia and its outcome in brainstem stroke particularly lateral medullary stroke motivated the author to present an actual case study of a patient who had dysphagia following a lateral medullary infarct. This paper documents the severity and management approach of dysphagia in brainstem stroke, with traditional dysphagia therapy and VitalStim therapy. Despite being diagnosed with a severe form of dysphagia followed by late treatment intervention, the patient had complete recovery of the swallowing function. PMID:25045555

The fate of medications evaluated for ischemic stroke pharmacotherapy over the period 1995-2015.

PubMed

Chen, Xiaoling; Wang, Kewei

2016-11-01

Stroke is a brain damage caused by a loss of blood supply to a portion of the brain, which requires prompt and effective treatment. The current pharmacotherapy for ischemic stroke primarily relies on thrombolysis using recombinant tissue plasminogen activators (rt-PAs) to breakdown blood clots. Neuroprotective agents that inhibit excitatory neurotransmitters are also used to treat ischemic stroke but have failed to translate into clinical benefits. This poses a major challenge in biomedical research to understand what causes the progressive brain cell death after stroke and how to develop an effective pharmacotherapy for stroke. This brief review analyzes the fate of about 430 potentially useful stroke medications over the period 1995-2015 and describes in detail those that successfully reached the market. Hopefully, the information from this analysis will shed light on how future stroke research can improve stroke drug discovery.

Recovery of Dysphagia in lateral medullary stroke.

PubMed

Gupta, Hitesh; Banerjee, Alakananda

2014-01-01

Lateral medullary stroke is typically associated with increased likelihood of occurrence of dysphagia and exhibits the most severe and persistent form. Worldwide little research exists on dysphagia in brainstem stroke. An estimated 15% of all patients admitted to stroke rehabilitation units experience a brainstem stroke out of which about 47% suffer from dysphagia. In India, a study showed that 22.3% of posterior circulation stroke patients develop dysphagia. Dearth of literature on dysphagia and its outcome in brainstem stroke particularly lateral medullary stroke motivated the author to present an actual case study of a patient who had dysphagia following a lateral medullary infarct. This paper documents the severity and management approach of dysphagia in brainstem stroke, with traditional dysphagia therapy and VitalStim therapy. Despite being diagnosed with a severe form of dysphagia followed by late treatment intervention, the patient had complete recovery of the swallowing function.

New perspectives on the pharmacotherapy of ischemic stroke.

PubMed

Bradberry, J Chris; Fagan, Susan C; Gray, David R; Moon, Yong S K

2004-01-01

To provide an overview of the impact of ischemic stroke and the steps that can be taken to reduce its burden through greater awareness of the disease, improved diagnosis and better treatment, with emphasis on the use of antiplatelet agents. Recent (1995-2003) published scientific literature, as identified by the authors through Medline searches, using the terms stroke, transient ischemic attack, cerebrovascular disease, atherothrombosis, risk factors, pharmacotherapy, prevention, and reviews on treatment. Recent systematic English-language review articles and reports of controlled randomized clinical trials were screened for inclusion. Ischemic stroke is generally the result of an atherothrombotic process leading to vessel obstruction or narrowing. Of the two types of ischemic stroke, thrombotic stroke is caused by a thrombus that develops within the cerebral vasculature, while embolic stroke arises from a distant embolus that lodges in a cerebral artery. The neurologic manifestations of stroke depend on the location of injury in the brain and the degree of ischemia or infarction. Symptoms may be reversible or irreversible and range from sensory deficits to hemiplegia. Risk factors for development of ischemic stroke include hypertension, diabetes, dyslipidemia, smoking, atrial fibrillation, prior stroke, and transient ischemic attack. Tissue plasminogen activator is currently the only available drug treatment for acute ischemic stroke. Stroke recurrence rates are high (about 40% over 5 years), and all ischemic stroke patients should receive antithrombotic therapy (unless contraindicated) for secondary prevention. Of the oral antiplatelet therapies, aspirin, clopidogrel (Plavix--Bristol-Myers Squibb/Sanofi Pharmaceuticals Partnership), and the extended-release dipyridamole plus aspirin combination are acceptable first-line agents, while anticoagulants (warfarin) are preferred in patients with atrial fibrillation. Lifestyle changes and drug therapy are important components of primary and secondary prevention strategies in ischemic stroke. Risk factors such as elevated blood pressure and high cholesterol should be aggressively treated. Antiplatelet agents, antihypertensive agents, and cholesterol-lowering agents are therapeutic cornerstones for secondary prevention.

Socioeconomic Status and Stroke Prevalence in Morocco: Results from the Rabat-Casablanca Study

PubMed Central

Engels, Thomas; Baglione, Quentin; Audibert, Martine; Viallefont, Anne; Mourji, Fouzi; El Alaoui Faris, Mustapha

2014-01-01

Background Stroke is a growing public health concern in low- and middle- income countries. Improved knowledge about the association between socioeconomic status and stroke in these countries would enable the development of effective stroke prevention and management strategies. This study presents the association between socioeconomic status and the prevalence of stroke in Morocco, a lower middle-income country. Methods Data on the prevalence of stroke and stroke-related risk factors were collected during a large population-based survey. The diagnosis of stroke in surviving patients was confirmed by neurologists while health, demographic, and socioeconomic characteristics of households were collected using structured questionnaires. We used Multiple Correspondence Analysis to develop a wealth index based on characteristics of the household dwelling as well as ownership of selected assets. We used logistic regressions controlling for multiple variables to assess the statistical association between socioeconomic status and stroke. Findings Our results showed a significant association between household socioeconomic status and the prevalence of stroke. This relationship was non-linear, with individuals from both the poorest (mainly rural) and richest (mainly urban) households having a lower prevalence of stroke as compared to individuals with medium wealth level. The latter belonged mainly to urban households with a lower socioeconomic status. When taking into account the urban population only, we observed that a third of poorest households experienced a significantly higher prevalence of stroke compared to the richest third (OR = 2.06; CI 95%: 1.09; 3.89). Conclusion We conclude that individuals from the most deprived urban households bear a higher risk of stroke than the rest of the population in Morocco. This result can be explained to a certain extent by the higher presence of behavioral risk factors in this specific category of the population, which leads in turn to metabolic and physiological risk factors of stroke, such as obesity, diabetes, and hypertension. PMID:24586649

25-hydroxyvitamin D levels and risk of stroke: A prospective study and meta-analysis

PubMed Central

Sun, Qi; Pan, An; Hu, Frank B.; Manson, JoAnn E.; Rexrode, Kathryn M.

2012-01-01

Background and Purpose Despite evidence suggesting that vitamin D deficiency may lead to elevated cardiovascular disease risk, results regarding the association of 25(OH)D levels with stroke risk are inconclusive. We aimed to examine this association in a prospective study in women and to summarize all existing data in a meta-analysis. Methods We measured 25(OH)D levels among 464 women who developed ischemic stroke and an equal number of controls who were free of stroke through 2006 in the Nurses’ Health Study (NHS). We searched MEDLINE and EMBASE for articles published through March 2011 that prospectively evaluated 25(OH)D levels in relation to stroke. Results After multivariable adjustment for lifestyle and dietary covariates, lower 25(OH)D levels were associated with an elevated risk of ischemic stroke in the NHS: the odds ratio (95% CI) comparing women in the lowest vs. highest tertiles was 1.49 (1.01, 2.18; Ptrend=0.04). We found 6 other prospective studies that examined 25(OH)D in relation to stroke outcomes. After pooling our results with these prospective studies that included 1,214 stroke cases in total, low 25(OH)D levels were associated with increased risk of developing stroke outcomes in comparison to high levels: the pooled relative risk (95% CI) was 1.52 (1.20, 1.85; I2 = 0.0%, Pheterogeneity=0.63). In two studies that explicitly examined ischemic stroke, this association was 1.59 (1.07, 2.12; I2 = 0.0%, Pheterogeneity=0.80). Conclusions These data provide evidence that low vitamin D levels are modestly associated with risk of stroke. Maintaining adequate vitamin D status may lower risk of stroke in women. PMID:22442173

Benefit of Anticoagulation Therapy in Hyperthyroidism-Related Atrial Fibrillation.

PubMed

Chan, Pak-Hei; Hai, Jojo; Yeung, Chun-Yip; Lip, Gregory Y H; Lam, Karen Siu-Ling; Tse, Hung-Fat; Siu, Chung-Wah

2015-08-01

Existing data on the risk of ischemic stroke in hyperthyroidism-related atrial fibrillation (AF) and the impact of long-term anticoagulation in these patients, particularly those with self-limiting AF, remain inconclusive. Risk of stroke in hyperthyroidism-related AF is the same as nonhyperthyroid counterparts. This was a single-center observational study of 9727 Chinese patients with nonvalvular AF from July 1997 to December 2011. Patients with AF diagnosed concomitantly with hyperthyroidism were identified. Primary and secondary endpoints were defined as hospitalization with ischemic stroke and intracranial hemorrhage in the first 2 years. Patient characteristics, duration of AF, and choice of antithrombotic therapy were recorded. Self-limiting AF was defined as <7 days' duration. Out of 9727 patients, 642 (6.6%) had concomitant hyperthyroidism and AF at diagnosis. For stroke prevention, 136 and 243 patients (21.1% and 37.9%) were prescribed warfarin and aspirin, respectively, whereas the remaining patients (41.0%) received no therapy. Ischemic stroke occurred in 50 patients (7.8%), and no patient developed hemorrhagic stroke. Patients with CHA2 DS2 -VASc of 0 did not develop stroke. Warfarin effectively reduced the incidence of stroke compared with aspirin or no therapy in patients with CHA2 DS2 -VASc ≥1 and non-self-limiting AF, but not in those with self-limiting AF or CHA2 DS2 -VASc of 0. Presence of hyperthyroidism did not confer additional risk of ischemic stroke compared with nonhyperthyroid AF. Patients with hyperthyroidism-related AF are at high risk of stroke (3.9% per year). Warfarin confers stroke prevention in patients with CHA2 DS2 -VASc ≥1 and non-self-limiting AF. Overall stroke risk was lower in hyperthyroid non-self-limiting AF patients compared with nonhyperthyroid counterparts. © 2015 Wiley Periodicals, Inc.

Community-based stroke system of care for Chinese rural areas.

PubMed

He, Mingli; Wang, Jin'e; Gong, Ling; Dong, Qing; Ji, Niu; Xing, Houxun; Zhou, Yuan; Qin, Sizhou; Wang, Huizheng; Zhang, Huamin; Hui, Rutai; Wang, Yibo

2014-08-01

Stroke system of care plays key roles both in providing effective therapies and in improving the overall outcome of patients with stroke. Our purpose was to develop and evaluate the system in Chinese rural areas. A stroke system of care was developed from November 2009 to November 2010 in 3 townships in Ganyu County. An additional 3 matched townships were invited as controls. We first investigated stroke management in these townships and then implemented stroke system of care and an education campaign in the 3 intervention townships. The effectiveness of the system was then evaluated. There were 1036 patients with new stroke among 344 345 subjects in the 6 rural communities. The incidence of stroke in the rural areas was 301/100 000, and the mortality rate was 55/100 000. The proportions significantly increased in the intervention communities after the implementation of the stroke system of care and education campaign when compared with the control communities, including patients presenting at rural hospitals within 3 hours of symptom onset (13.6% versus 8.7%; P=0.017), diagnosed by computed tomographic scanning within 24 hours of admission (65.3% versus 58.5%; P=0.034), and received thrombolytic treatment (3.9% versus 1.7%; P=0.038). During the 1-year follow-up, 32 (6.5%) patients with stroke in the intervention communities and 48 (10.1%) in the control communities died. The disability rate of stroke was significantly reduced in the intervention communities at postintervention (38.4% versus 48.1%; P=0.001). A stroke system of care would be reliable and practical in Chinese rural areas. http://www.chictr.org. Unique identifier: ChiCTR-RCH-13003408. © 2014 American Heart Association, Inc.

Prevalence of stroke and related burden among older people living in Latin America, India and China

PubMed Central

Schoenborn, Claudia; Kalra, Lalit; Acosta, Daisy; Guerra, Mariella; Huang, Yueqin; Jacob, K S; Llibre Rodriguez, Juan J; Salas, Aquiles; Sosa, Ana Luisa; Williams, Joseph D; Liu, Zhaorui; Moriyama, Tais; Valhuerdi, Adolfo; Prince, Martin J

2011-01-01

Objectives Despite the growing importance of stroke in developing countries, little is known of stroke burden in survivors. The authors investigated the prevalence of self-reported stroke, stroke-related disability, dependence and care-giver strain in Latin America (LA), China and India. Methods Cross-sectional surveys were conducted on individuals aged 65+ (n=15 022) living in specified catchment areas. Self-reported stroke diagnosis, disability, care needs and care giver burden were assessed using a standardised protocol. For those reporting stroke, the correlates of disability, dependence and care-giver burden were estimated at each site using Poisson or linear regression, and combined meta-analytically. Results The prevalence of self-reported stroke ranged between 6% and 9% across most LA sites and urban China, but was much lower in urban India (1.9%), and in rural sites in India (1.1%), China (1.6%) and Peru (2.7%). The proportion of stroke survivors needing care varied between 20% and 39% in LA sites but was higher in rural China (44%), urban China (54%) and rural India (73%). Comorbid dementia and depression were the main correlates of disability and dependence. Conclusion The prevalence of stroke in urban LA and Chinese sites is nearly as high as in industrialised countries. High levels of disability and dependence in the other mainly rural and less-developed sites suggest underascertainment of less severe cases as one likely explanation for the lower prevalence in those settings. As the health transition proceeds, a further increase in numbers of older stroke survivors is to be anticipated. In addition to prevention, stroke rehabilitation and long-term care needs should be addressed. PMID:21402745

Door-to-door capture of incident and prevalent stroke cases in Durango, Mexico: the Brain Attack Surveillance in Durango Study.

PubMed

Cantu-Brito, Carlos; Majersik, Jennifer J; Sánchez, Brisa N; Ruano, Angel; Becerra-Mendoza, Daniela; Wing, Jeffrey J; Morgenstern, Lewis B

2011-03-01

Stroke incidence and prevalence estimates in developing countries should include stroke cases not presenting to hospital. We performed door-to-door stroke case ascertainment in Durango Municipality, Mexico, to estimate stroke incidence and prevalence and to determine the error made by only ascertaining hospital cases. Between September 2008 and March 2009, 1996 housing units were randomly sampled to screen for stroke in Durango Municipality residents 35 years of age and older. Field workers utilized a validated screening tool. Those screening positive were referred to a neurologist for history and examination and a head CT scan. Prevalence and cumulative incidence from the door-to-door surveillance were calculated and compared with previously reported hospitalization rates during the same defined time. Respondents included 2437 subjects from 1419 homes. The refusal rate was 3.8%. Twenty subjects had verified or probable stroke. The prevalence of probable or verified stroke was 7.7 per 1000 (95% CI, 4.3 per 1000-11.2 per 1000). Five patients had a stroke during the time of the hospital surveillance, yielding a cumulative incidence of 232.3 per 100 000 (95% CI, 27.8-436.9). Two of the 5 cases were captured by door-to-door surveillance but not by hospital surveillance. This study provides the first community-based stroke prevalence and incidence estimates in Mexico. The wide confidence intervals, despite the large number of surveyed housing units, suggest the need for more advanced sampling strategies for stroke surveillance in the developing world.

Door-to-door capture of incident and prevalent stroke cases in Durango, Mexico – the Brain Attack Surveillance in Durango (BASID) Study

PubMed Central

Cantu-Brito, Carlos; Majersik, Jennifer J; Sánchez, Brisa N; Ruano, Angel; Becerra-Mendoza, Daniela; Wing, Jeffrey J; Morgenstern, Lewis B

2011-01-01

Background and Purpose Stroke incidence and prevalence estimates in developing countries should include stroke cases not presenting to hospital. We performed door-to-door stroke case ascertainment in Durango Municipality, Mexico to estimate stroke incidence and prevalence, and to determine the error made by only ascertaining hospital cases. Methods Between September 2008 and March 2009, 1996 housing units were randomly sampled to screen for stroke in Durango Municipality residents ≥35 years of age. Field workers utilized a validated screening tool. Those screening positive were referred to a neurologist for history and examination and if confirmed, a head CT scan. Prevalence and cumulative incidence from the door-to-door surveillance were calculated and compared with previously reported hospitalization rates during the same defined time. Results Respondents included 2437 subjects from 1419 homes. The refusal rate was 3.8%. Twenty subjects had verified or probable stroke. The prevalence of probable or verified stroke was 7.7/1000 (95% CI: 4.3/1000, 11.2/1000). Five patients had a stroke during the time of the hospital surveillance, yielding a cumulative incidence of 232.3/100,000 (95% CI: 27.8, 436.9). Two of the 5 cases were captured by door-to-door surveillance but not by hospital surveillance. Conclusions This study provides the first community-based stroke prevalence and incidence estimates in Mexico. The wide confidence intervals, despite the large number of surveyed housing units, suggest the need for more advanced sampling strategies for stroke surveillance in the developing world. PMID:21212398

Association between ambient air pollution and hospitalization for ischemic and hemorrhagic stroke in China: A multicity case-crossover study.

PubMed

Liu, Hui; Tian, Yaohua; Xu, Yan; Huang, Zhe; Huang, Chao; Hu, Yonghua; Zhang, Jun

2017-11-01

There is growing interest in the association between ambient air pollution and stroke, but few studies have investigated the association in developing countries. The primary objective of this study was to examine the association between levels of ambient air pollutants and hospital admission for stroke in China. A time-stratified case-crossover analysis was conducted between 2014 and 2015 in 14 large Chinese cities among 200,958 ischemic stroke and 41,746 hemorrhagic stroke hospitalizations. We used conditional logistic regression to estimate the percentage changes in stroke admissions in relation to interquartile range increases in air pollutants. Air pollution was positively associated with ischemic stroke. A difference of an interquartile range of the 6-day average for particulate matter less than 10 μm in aerodynamic diameter, sulfur dioxide, nitrogen dioxide, carbon monoxide, and ozone corresponded to 0.7% (95% CI: 0%, 1.4%), 1.6% (95% CI: 1.0%, 2.3%), 2.6% (95% CI: 1.8%, 3.5%), 0.5% (95% CI: -0.2%, 1.1%), and 1.3% (95% CI: 0.3%, 2.3%) increases in ischemic stroke admissions, respectively. For hemorrhagic stroke, we observed the only significant association in relation to nitrogen dioxide on the current day (percentage change: 1.6%; 95% CI: 0.3%, 2.9%). Our findings contribute to the limited scientific literature concerning the effect of ambient air pollution on stroke in developing countries. Our findings may have significant public health implications for primary prevention of stroke in China. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of X-Y servo pneumatic-piezoelectric hybrid actuators for position control with high response, large stroke and nanometer accuracy.

PubMed

Chiang, Mao-Hsiung

2010-01-01

This study aims to develop a X-Y dual-axial intelligent servo pneumatic-piezoelectric hybrid actuator for position control with high response, large stroke (250 mm, 200 mm) and nanometer accuracy (20 nm). In each axis, the rodless pneumatic actuator serves to position in coarse stroke and the piezoelectric actuator compensates in fine stroke. Thus, the overall control systems of the single axis become a dual-input single-output (DISO) system. Although the rodless pneumatic actuator has relatively larger friction force, it has the advantage of mechanism for multi-axial development. Thus, the X-Y dual-axial positioning system is developed based on the servo pneumatic-piezoelectric hybrid actuator. In addition, the decoupling self-organizing fuzzy sliding mode control is developed as the intelligent control strategies. Finally, the proposed novel intelligent X-Y dual-axial servo pneumatic-piezoelectric hybrid actuators are implemented and verified experimentally.

Development of X-Y Servo Pneumatic-Piezoelectric Hybrid Actuators for Position Control with High Response, Large Stroke and Nanometer Accuracy

PubMed Central

Chiang, Mao-Hsiung

2010-01-01

This study aims to develop a X-Y dual-axial intelligent servo pneumatic-piezoelectric hybrid actuator for position control with high response, large stroke (250 mm, 200 mm) and nanometer accuracy (20 nm). In each axis, the rodless pneumatic actuator serves to position in coarse stroke and the piezoelectric actuator compensates in fine stroke. Thus, the overall control systems of the single axis become a dual-input single-output (DISO) system. Although the rodless pneumatic actuator has relatively larger friction force, it has the advantage of mechanism for multi-axial development. Thus, the X-Y dual-axial positioning system is developed based on the servo pneumatic-piezoelectric hybrid actuator. In addition, the decoupling self-organizing fuzzy sliding mode control is developed as the intelligent control strategies. Finally, the proposed novel intelligent X-Y dual-axial servo pneumatic-piezoelectric hybrid actuators are implemented and verified experimentally. PMID:22319266

Lipid profile in cerebrovascular accidents.

PubMed

Togha, Mansoureh; Gheini, Mohamad Reza; Ahmadi, Babak; Khashaiar, Patricia; Razeghi, Soodeh

2011-01-01

Changes in the lipid profile have been suggested as a risk factor for developing ischemic stroke. Their role in intra-cerebral hemorrhage, however, is not clear. The present study was designed to evaluate the lipid profile levels of patients who had experienced an acute stroke during the first 24-hour and to compare these levels in different patients suffering from the stroke, either hemorrhagic or ischemic, and healthy individuals. In this cross-sectional study, 258 consecutive patients with acute stroke admitted to the neurology department of our center during September 2006 and September 2007 were studied. As for the control group, 187 apparently healthy subjects living in the same community and matched for age and sex were selected. Lipid profile was measured and compared between the three groups. In the patients' group, 65 suffered from hemorrhagic stroke (group 1) and the other 193 had ischemic stroke (group 2). Except for TG values, there was no significant difference among the ischemic and hemorrhagic lipid profile. Age, cholesterol, and LDL influenced the risk of developing an ischemic stroke; TG was not reported as a risk factor or a protective one. While the comparison of data retrieved from patients suffering from hemorrhagic strokes with the controls, revealed LDL as the risk factor contributing to the development of ICH whereas TG was reported as a protective factor. It could be concluded that LDL level can be considered as a risk factor for both ischemic and hemorrhagic cerebral events.

Smoking as a Crucial Independent Determinant of Stroke

PubMed Central

Paul, Seana L; Thrift, Amanda G; Donnan, Geoffrey A

2004-01-01

Background Although smoking is known to be powerful risk factor for other vascular diseases, such as cardiac and peripheral vascular disease, only relatively recently has evidence for the role of smoking in the development of stroke been established. The reasons for this advance lie in the acknowledgement that stroke is a heterogeneous disease, in which its subtypes are associated with different risk factors. Furthermore, improvements in the stringency of epidemiological studies and the greater use of CT scanning have enabled the role of smoking in the development of stroke to be elucidated. Summary of review This is a qualitative examination of high quality epidemiological studies in which the role of smoking and passive smoking, as a risk factor for cerebral infarction, intracerebral haemorrhage and subarachnoid haemorrhage, is examined. In addition, the pathological mechanisms by which smoking or passive smoking may contribute to the development of stroke are reviewed. Conclusion Smoking is a crucial independent determinant of cerebral infarction and subarachnoid haemorrhage, however its role in intracerebral haemorrhage is unclear. Although studies are limited, there is evidence that exposure to passive smoking may also increase the risk of stroke. Smoking appears to be involved in the pathogenesis of stroke via direct injury to the vasculature and also by altering haemodynamic factors within the circulation. Importantly, smoking is modifiable risk factor for stroke. Therefore, the encouragement of smoking cessation may result in a substantial reduction in the incidence of this devastating disease.

Smoking as a Crucial Independent Determinant of Stroke

PubMed Central

Paul, Seana L; Thrift, Amanda G; Donnan, Geoffrey A

2004-01-01

Background Although smoking is known to be powerful risk factor for other vascular diseases, such as cardiac and peripheral vascular disease, only relatively recently has evidence for the role of smoking in the development of stroke been established. The reasons for this advance lie in the acknowledgement that stroke is a heterogeneous disease, in which its subtypes are associated with different risk factors. Furthermore, improvements in the stringency of epidemiological studies and the greater use of CT scanning have enabled the role of smoking in the development of stroke to be elucidated. Summary of review This is a qualitative examination of high quality epidemiological studies in which the role of smoking and passive smoking, as a risk factor for cerebral infarction, intracerebral haemorrhage and subarachnoid haemorrhage, is examined. In addition, the pathological mechanisms by which smoking or passive smoking may contribute to the development of stroke are reviewed. Conclusion Smoking is a crucial independent determinant of cerebral infarction and subarachnoid haemorrhage, however its role in intracerebral haemorrhage is unclear. Although studies are limited, there is evidence that exposure to passive smoking may also increase the risk of stroke. Smoking appears to be involved in the pathogenesis of stroke via direct injury to the vasculature and also by altering haemodynamic factors within the circulation. Importantly, smoking is modifiable risk factor for stroke. Therefore, the encouragement of smoking cessation may result in a substantial reduction in the incidence of this devastating disease. PMID:19570273

Stroke care programme in Aragon (PAIA): strategy and outcomes for the period 2009-2014.

PubMed

Marta Moreno, J; Bestué Cardiel, M; Giménez Muñoz, A; Palacín Larroy, M

2018-06-01

In 2008, stroke mortality, morbidity, and disability rates in Aragon were higher than the average in Spain. These data underscored the need to develop a stroke care programme (PAIA). We present the dynamics of planning, implementation, evaluation, and improvement developed between 2009 and 2014 as well as the results of the PAIA after that 5-year period. Structure, processes, and outcomes have improved with reference to the key indicators of healthcare (audit: 2008, 2010, 2012) among others: stroke rate in 2013 was 2.07 (2.36 in 2008); 78% of strokes were managed in stroke units in 2014 (30% in 2008); rate of fibrinolysis was 8.3% in 2014 (4.4% in 2010); fibrinolysis was administered in secondary hospitals (30% of the total); fibrinolysis was administered by Telestroke in 9%; stroke mortality decreased (38%); 67.7 years of potential life lost (YPLL) in 2013 (144 in 2008); nurse training; development of neurosonology; networking; sharing protocols and best practices between health sectors, etc. CONCLUSIONS: Integrated process management and multidisciplinary teams distributed and deployed over an entire territory with established protocols, references, evaluations, and continuous development, have been proven powerful tools to ensure both quality and equality. The PAIA is a good example of clinical governance and networking due to its dynamic and sustained improvement and cooperation between clinicians. Copyright © 2016 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

Epidemiology, pathophysiology, and treatment of hypertension in ischaemic stroke patients.

PubMed

Hisham, Nur Fatirul; Bayraktutan, Ulvi

2013-10-01

Stroke continues to be one of the leading causes of mortality and morbidity worldwide. There are 2 main types of stroke: ischaemic strokes, which are caused by obstruction of the blood vessels leading to or within the brain, and haemorrhagic strokes, which are induced by the disruption of blood vessels. Stroke is a disease of multifactorial aetiology that may develop as an end state in patients with serious vascular conditions--most notably, uncontrolled arterial hypertension--thereby necessitating the effective control of this risk factor to prevent stroke or its recurrence. This paper focuses specifically on the epidemiology and pathogenesis of ischaemic stroke mainly in chronically hypertensive patients and pays particular attention to the efficacy of a select group of routinely used major antihypertensive drugs (i.e., angiotensin-converting enzyme inhibitors, angiotensin II type 1 receptor blockers, and calcium channel blockers) in the treatment of strokes. Copyright © 2013 National Stroke Association. Published by Elsevier Inc. All rights reserved.

National Service Framework for Older People: stroke coordinators.

PubMed

McDonald, Paul S; Mayer, Peter; Dunn, Linda

The National Service Framework (NSF) for Older People aims to develop integrated stroke services with specialized treatment, carer involvement, secondary prevention and rehabilitation. There is an emphasis upon the role of stroke coordinators. The aim of this study was to examine the relationships between stroke coordinators and other agencies involved in stroke care, and to describe stroke coordinators' current roles. Interviews with 11 stroke coordinators across the West Midlands region took place and were evaluated using a grounded theory approach. The roles of stroke coordinators and the perceived levels of integration among stroke services varied between localities. In a few areas, a number of 'adhesive' factors helped bond the coordinator role to successful integration, while in most areas the absence of all or some of these factors made the role less effective. To meet the demands of the NSF, a stroke coordinator's role needs to be a high profile, corporate function, requiring a higher level of autonomy, accountability and responsibility, and demanding creativity and innovation from post holders.

Stroke epidemiology, prevention, and management strategies at a regional level: Latin America and the Caribbean.

PubMed

Lavados, Pablo M; Hennis, Anselm J M; Fernandes, Jefferson G; Medina, Marco T; Legetic, Branca; Hoppe, Arnold; Sacks, Claudio; Jadue, Liliana; Salinas, Rodrigo

2007-04-01

Stroke is a major health problem in Latin American and Caribbean countries. In this paper, we review the epidemiology, aetiology, and management of stroke in the region based on a systematic search of articles published in Spanish, Portuguese, and English. Stroke mortality is higher than in developed countries but rates are declining. Population-based studies show variations in incidence of strokes: lower rates of ischaemic stroke and similar rates of intracranial haemorrhages, compared with other regions. A significant proportion of strokes in these populations can be attributed to a few preventable risk factors. Some countries have published national clinical guidelines, although much needs to be done in the organisation of care and rehabilitation. Even though the burden of stroke is high, there is a paucity of information for implementing evidence-based management. The Global Stroke Initiative, the WHO STEPS Stroke surveillance, and WHO-PREMISE projects provide opportunities for surveillance at institutional and community levels.

Multiattribute selection of acute stroke imaging software platform for Extending the Time for Thrombolysis in Emergency Neurological Deficits (EXTEND) clinical trial.

PubMed

Churilov, Leonid; Liu, Daniel; Ma, Henry; Christensen, Soren; Nagakane, Yoshinari; Campbell, Bruce; Parsons, Mark W; Levi, Christopher R; Davis, Stephen M; Donnan, Geoffrey A

2013-04-01

The appropriateness of a software platform for rapid MRI assessment of the amount of salvageable brain tissue after stroke is critical for both the validity of the Extending the Time for Thrombolysis in Emergency Neurological Deficits (EXTEND) Clinical Trial of stroke thrombolysis beyond 4.5 hours and for stroke patient care outcomes. The objective of this research is to develop and implement a methodology for selecting the acute stroke imaging software platform most appropriate for the setting of a multi-centre clinical trial. A multi-disciplinary decision making panel formulated the set of preferentially independent evaluation attributes. Alternative Multi-Attribute Value Measurement methods were used to identify the best imaging software platform followed by sensitivity analysis to ensure the validity and robustness of the proposed solution. Four alternative imaging software platforms were identified. RApid processing of PerfusIon and Diffusion (RAPID) software was selected as the most appropriate for the needs of the EXTEND trial. A theoretically grounded generic multi-attribute selection methodology for imaging software was developed and implemented. The developed methodology assured both a high quality decision outcome and a rational and transparent decision process. This development contributes to stroke literature in the area of comprehensive evaluation of MRI clinical software. At the time of evaluation, RAPID software presented the most appropriate imaging software platform for use in the EXTEND clinical trial. The proposed multi-attribute imaging software evaluation methodology is based on sound theoretical foundations of multiple criteria decision analysis and can be successfully used for choosing the most appropriate imaging software while ensuring both robust decision process and outcomes. © 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.

Development and application of Model of Resource Utilization, Costs, and Outcomes for Stroke (MORUCOS): an Australian economic model for stroke.

PubMed

Mihalopoulos, Catherine; Cadilhac, Dominique A; Moodie, Marjory L; Dewey, Helen M; Thrift, Amanda G; Donnan, Geoffrey A; Carter, Robert C

2005-01-01

To outline the development, structure, data assumptions, and application of an Australian economic model for stroke (Model of Resource Utilization, Costs, and Outcomes for Stroke [MORUCOS]). The model has a linked spreadsheet format with four modules to describe the disease burden and treatment pathways, estimate prevalence-based and incidence-based costs, and derive life expectancy and quality of life consequences. The model uses patient-level, community-based, stroke cohort data and macro-level simulations. An interventions module allows options for change to be consistently evaluated by modifying aspects of the other modules. To date, model validation has included sensitivity testing, face validity, and peer review. Further validation of technical and predictive accuracy is needed. The generic pathway model was assessed by comparison with a stroke subtypes (ischemic, hemorrhagic, or undetermined) approach and used to determine the relative cost-effectiveness of four interventions. The generic pathway model produced lower costs compared with a subtypes version (total average first-year costs/case AUD$ 15,117 versus AUD$ 17,786, respectively). Optimal evidence-based uptake of anticoagulation therapy for primary and secondary stroke prevention and intravenous thrombolytic therapy within 3 hours of stroke were more cost-effective than current practice (base year, 1997). MORUCOS is transparent and flexible in describing Australian stroke care and can effectively be used to systematically evaluate a range of different interventions. Adjusting results to account for stroke subtypes, as they influence cost estimates, could enhance the generic model.

Critical early thrombolytic and endovascular reperfusion therapy for acute ischemic stroke victims: a call for adjunct neuroprotection.

PubMed

Lapchak, Paul A

2015-10-01

Today, there is an enormous amount of excitement in the field of stroke victim care due to the recent success of MR. CLEAN, SWIFT PRIME, ESCAPE, EXTEND-IA, and REVASCAT endovascular trials. Successful intravenous (IV) recombinant tissue plasminogen activator (rt-PA) clinical trials [i.e., National Institute of Neurological Disorders and Stroke (NINDS) rt-PA trial, Third European Cooperative Acute Stroke Study (ECASSIII), and Third International Stroke study (IST-3)] also need to be emphasized. In the recent endovascular and thrombolytic trials, there is statistically significant improvement using both the National Institutes of Health Stroke Scale (NIHSS) and the modified Rankin Score (mRS) scale, but neither approach promotes complete recovery in patients enrolled within any particular NIHSS or mRS score tier. Absolute improvement (mRS 0-2 at 90 days) with endovascular therapy is 13.5-31 %, whereas thrombolytics alone also significantly improve patient functional independence, but to a lesser degree (NINDS rt-PA trial 13 %). This article has 3 main goals: (1) first to emphasize the utility and cost-effectiveness of rt-PA to treat stroke; (2) second to review the recent endovascular trials with respect to efficacy, safety, and cost-effectiveness as a stroke treatment; and (3) to further consider and evaluate strategies to develop novel neuroprotective drugs. A thesis will be put forth so that future stroke trials and therapy development can optimally promote recovery so that stroke victims can return to "normal" life.

Development, Implementation, and Evaluation of a Telemedicine Service for the Treatment of Acute Stroke Patients: TeleStroke

PubMed Central

2012-01-01

Background Health care service based on telemedicine can reduce both physical and time barriers in stroke treatments. Moreover, this service connects centers specializing in stroke treatment with other centers and practitioners, thereby increasing accessibility to neurological specialist care and fibrinolytic treatment. Objective Development, implementation, and evaluation of a care service for the treatment of acute stroke patients based on telemedicine (TeleStroke) at Virgen del Rocío University Hospital. Methods The evaluation phase, conducted from October 2008 to January 2011, involved patients who presented acute stroke symptoms confirmed by the emergency physician; they were examined using TeleStroke in two hospitals, at a distance of 16 and 110 kilometers from Virgen del Rocío University Hospital. We analyzed the number of interconsultation sheets, the percentage of patients treated with fibrinolysis, and the number of times they were treated. To evaluate medical professionals’ acceptance of the TeleStroke system, we developed a web-based questionnaire using a Technology Acceptance Model. Results A total of 28 patients were evaluated through the interconsultation sheet. Out of 28 patients, 19 (68%) received fibrinolytic treatment. The most common reasons for not treating with fibrinolysis included: clinical criteria in six out of nine patients (66%) and beyond the time window in three out of nine patients (33%). The mean “onset-to-hospital” time was 69 minutes, the mean time from admission to CT image was 33 minutes, the mean “door-to-needle” time was 82 minutes, and the mean “onset-to-needle” time was 150 minutes. Out of 61 medical professionals, 34 (56%) completed a questionnaire to evaluate the acceptability of the TeleStroke system. The mean values for each item were over 6.50, indicating that respondents positively evaluated each item. This survey was assessed using the Cronbach alpha test to determine the reliability of the questionnaire and the results obtained, giving a value of 0.97. Conclusions The implementation of TeleStroke has made it possible for patients in the acute phase of stroke to receive effective treatment, something that was previously impossible because of the time required to transfer them to referral hospitals. PMID:23612154

Application of the World Stroke Organization health system indicators and performance in Australia, Singapore, and the USA.

PubMed

Tse, Tamara; Carey, Leeanne; Cadilhac, Dominique; Koh, Gerald Choon-Huat; Baum, Carolyn

2016-10-01

Aim To examine how Australia, Singapore and the United States of America (USA) match to the World Stroke Organization Global Stroke Services health system monitoring indicators (HSI). Design Descriptive comparative study Participants The health systems of Australia, Singapore, the USA. Outcome measures Published data available from each country were mapped to the 10 health system monitoring indicators proposed by the World Stroke Organization. Results Most health system monitoring indicators were at least partially met in each country. Thrombolytic agents were available for use in acute stroke. Stroke guidelines and stroke registry data were available in all three countries. Stroke incidence, prevalence, and mortality rates were available but at non-uniform times post-stroke. The International Classification of Disease 9 or 10 coding systems are used in all three countries. Standardized clinical audits are routine in Australia and the USA, but not in Singapore. The use of the modified Rankin Scale is collected sub-acutely but not at one year post-stroke in all three countries. Conclusions The three developed countries are performing well against the World Stroke Organization health system monitoring indicators for acute and sub-acute stroke care. However, improvements in stroke risk assessment and at one-year post-stroke outcome measurement are needed.

Analysis of speed, stroke rate, and stroke distance for world-class breaststroke swimming.

PubMed

Garland Fritzdorf, Stephen; Hibbs, Angela; Kleshnev, Valery

2009-02-15

Speed in aquatic locomotion is determined by stroke distance and stroke rate, but it does not always follow that an increase in stroke rate will lead to an increase in speed. Kleshnev (2006) developed a method to evaluate the relationship between speed and stroke rate during rowing - the effective work per stroke. In this case study, the effective work per stroke was determined for a male world-class 100-m breaststroke swimmer for seven races in major championships and compared between: each of the seven races; each quarter within each race; and the best swims of this case study and seven other world-class swimmers. The effective work per stroke was related to race performance, with the fastest race having the highest effective work per stroke and lowest stroke rate, with slower races having low effectiveness and high stroke rate (R(2) = 0.85). The effective work per stroke was reduced in a race as the swimmer fatigued. The within-race standard deviation of effectiveness was lower in fast swims (R(2) = 0.84). This analysis has identified some characteristics of fast swimming: high effectiveness, optimal stroke rate, and a flat effectiveness profile. Training and racing strategies can now be devised to improve performance by increasing the sensitivity of assessment of strengths and weaknesses in individuals.

Lightning activity related to satellite and radar observations of a mesoscale convective system over Texas on 7 8 April 2002

NASA Astrophysics Data System (ADS)

Dotzek, Nikolai; Rabin, Robert M.; Carey, Lawrence D.; MacGorman, Donald R.; McCormick, Tracy L.; Demetriades, Nicholas W.; Murphy, Martin J.; Holle, Ronald L.

2005-07-01

A multi-sensor study of the leading-line, trailing-stratiform (LLTS) mesoscale convective system (MCS) that developed over Texas in the afternoon of 7 April 2002 is presented. The analysis relies mainly on operationally available data sources such as GOES East satellite imagery, WSR-88D radar data and NLDN cloud-to-ground flash data. In addition, total lightning information in three dimensions from the LDAR II network in the Dallas-Ft. Worth region is used. GOES East satellite imagery revealed several ring-like cloud top structures with a diameter of about 100 km during MCS formation. The Throckmorton tornadic supercell, which had formed just ahead of the developing linear MCS, was characterized by a high CG+ percentage below a V-shaped cloud top overshoot north of the tornado swath. There were indications of the presence of a tilted electrical dipole in this storm. Also this supercell had low average CG- first stroke currents and flash multiplicities. Interestingly, especially the average CG+ flash multiplicity in the Throckmorton storm showed oscillations with an estimated period of about 15 min. Later on, in the mature LLTS MCS, the radar versus lightning activity comparison revealed two dominant discharge regions at the back of the convective leading edge and a gentle descent of the upper intracloud lightning region into the trailing stratiform region, apparently coupled to hydrometeor sedimentation. There was evidence for an inverted dipole in the stratiform region of the LLTS MCS, and CG+ flashes from the stratiform region had high first return stroke peak currents.

Nursing application of Bobath principles in stroke care.

PubMed

Passarella, P M; Lewis, N

1987-04-01

The nursing approach in the care of stroke patients has a direct impact on functional outcome. Nursing application of Bobath principles in stroke care offers a nursing focus on involvement of the affected side; facilitation of normal tone, posture, and movement; and development of more normal function. A research study evaluating the functional gains of stroke patients demonstrated a significant level of functional improvement in those treated with Bobath principles over stroke patients treated with the traditional nursing approach. Practical methods for applying Bobath principles in patient care activities are described. These therapeutic methods provide nurses with the means to maximize stroke patients' potential and further influence their functional recovery.

Orbiter Landing Loads Math Model Description and Correlation with ALT Flight Data

NASA Technical Reports Server (NTRS)

Hamilton, D. A.; Schliesing, J. A.; Zupp, G. A., Jr.

1980-01-01

Results of the space shuttle approach and landing test are examined in order to assess landing gear characteristics and performance and verify landing dynamic analyses. The landing gears were instrumented with load-calibrated strain gages, a wheel-speed sensor, and strut stroke measurement devices. The mathematical procedure used in predicting the shuttle touchdown loads and dynamics is presented together with the comparisons between measured flight data and the analytical predictions. Conclusions from these data are also presented.

Improving Situational Awareness in the Counter-IED Fight with the Utilization of Unmanned Sensor Systems

DTIC Science & Technology

2009-06-01

Resistant Ambush Protected (MRAP) vehicles, which were designed to withstand an antitank mine (Eisler, 2007). An EFP can penetrate a thickness of armored...These robots weigh less than 100 pounds, are man-portable, and move on small treads with seven speed settings. The TALON is controlled with a...is powered by a two-stroke piston engine and has a steerable nose and main gear, with tires suitable for rough terrain. The Tern utilizes a GPS

ALDH2 protects against stroke by clearing 4-HNE

PubMed Central

Guo, Jin-Min; Liu, Ai-Jun; Zang, Pu; Dong, Wen-Zhe; Ying, Li; Wang, Wei; Xu, Pu; Song, Xu-Rui; Cai, Jun; Zhang, She-Qing; Duan, Jun-Li; Mehta, Jawahar L; Su, Ding-Feng

2013-01-01

Aldehyde dehydrogenase 2 (ALDH2) is a mitochondrial enzyme that metabolizes ethanol and toxic aldehydes such as 4-hydroxy-2-nonenal (4-HNE). Using an unbiased proteomic search, we identified ALDH2 deficiency in stroke-prone spontaneously hypertensive rats (SHR-SP) as compared with spontaneously hypertensive rats (SHR). We concluded the causative role of ALDH2 deficiency in neuronal injury as overexpression or activation of ALDH2 conferred neuroprotection by clearing 4-HNE in in vitro studies. Further, ALDH2-knockdown rats revealed the absence of neuroprotective effects of PKCε. Moderate ethanol administration that is known to exert protection against stroke was shown to enhance the detoxification of 4-HNE, and to protect against ischemic cerebral injury through the PKCε-ALDH2 pathway. In SHR-SP, serum 4-HNE level was persistently elevated and correlated inversely with the lifespan. The role of 4-HNE in stroke in humans was also suggested by persistent elevation of its plasma levels for at least 6 months after stroke. Lastly, we observed that 21 of 1 242 subjects followed for 8 years who developed stroke had higher initial plasma 4-HNE levels than those who did not develop stroke. These findings suggest that activation of the ALDH2 pathway may serve as a useful index in the identification of stroke-prone subjects, and the ALDH2 pathway may be a potential target of therapeutic intervention in stroke. PMID:23689279

Develop a wearable ankle robot for in-bed acute stroke rehabilitation.

PubMed

Ren, Yupeng; Xu, Tao; Wang, Liang; Yang, Chung Yong; Guo, Xin; Harvey, Richard L; Zhang, Li-Qun

2011-01-01

Movement training is important in motor recovery post stroke and early intervention is critical to stroke rehabilitation. However, acute stroke survivors are actively trained with activities helpful for recovery of mobility in only 13% of the time in the acute phase. Considering the first few months post stroke is critical in stroke recovery (neuroplasticity), there is a strong need for movement therapy and manipulate/mobilize the joints. There is a lack of in-bed robotic rehabilitation in acute stroke. This study seeks to meet the clinic need and deliver intensive passive and active movement therapy using a wearable robot to enhance motor function in acute stroke. Passively, the wearable robot stretches the joint to its extreme positions safely and forcefully. Actively, movement training is conducted and game playing is used to guide and motivate the patient in movement training.

The impact of surgical left atrial appendage amputation/ligation on stroke prevention in patients undergoing off-pump coronary artery bypass grafting.

PubMed

Endo, Daisuke; Kato, Tomoko S; Iwamura, Tai; Oishi, Atsumi; Yokoyama, Yasutaka; Kuwaki, Kenji; Inaba, Hirotaka; Amano, Atsushi

2017-06-01

Stroke is a major adverse event in patients developing atrial fibrillation (AF) after cardiac surgery. Surgical left atrial appendage amputation/ligation (LAA-A/L) during off-pump coronary artery bypass grafting (OPCAB) is routinely performed in our institution. We analyzed 578 consecutive patients (mean age 69 years, male 82%) undergoing OPCAB with or without concomitant LAA-A/L from 2011 to 2014 at our institution in a prospective observational manner. The safety and efficacy of the concomitant LAA-A/L on preventing early (<30 days) and overall postoperative stroke were examined. A total of 193 patients (33.4%) underwent LAA-A/L, consisting of amputation in 154 and ligation in 39 patients (80 and 20% of the cases, respectively). Preoperative characteristics, operative time, requirement of blood transfusion, and 30-day mortality were not significantly different between those with and without LAA-A/L. The incidences of postoperative AF and early and overall stroke were not significantly different between the groups in the analysis based on a total cohort. In a subanalysis of patients without LAA-A/L, early and overall stroke occurred more frequently in those developing postoperative AF than those without AF (2.8 vs. 0%; p = 0.005, 6.2 vs. 1.5%; p = 0.017, respectively), while in patients receiving LAA-A/L, stroke incidences did not differ between those with and without AF. Multivariate logistic regression showed postoperative AF without LAA-A/L as the only independent positive predictor of overall stroke (OR 3.69, p = 0.03). Concomitant LAA-A/L with OPCAB can safely prevent postoperative stroke occurrence in case patients develop AF, the most common arrhythmia associated with stroke.

Development of an education campaign to reduce delays in pre-hospital response to stroke.

PubMed

Caminiti, Caterina; Schulz, Peter; Marcomini, Barbara; Iezzi, Elisa; Riva, Silvia; Scoditti, Umberto; Zini, Andrea; Malferrari, Giovanni; Zedde, Maria Luisa; Guidetti, Donata; Montanari, Enrico; Baratti, Mario; Denti, Licia

2017-06-24

Systematic reviews call for well-designed trials with clearly described intervention components to support the effectiveness of educational campaigns to reduce patient delay in stroke presentation. We herein describe the systematic development process of a campaign aimed to increase stroke awareness and preparedness. Campaign development followed Intervention Mapping (IM), a theory- and evidence-based tool, and was articulated in two phases: needs assessment and intervention development. In phase 1, two cross-sectional surveys were performed, one aiming to measure stroke awareness in the target population and the other to analyze the behavioral determinants of prehospital delay. In phase 2, a matrix of proximal program objectives was developed, theory-based intervention methods and practical strategies were selected and program components and materials produced. In phase 1, the survey on 202 citizens highlighted underestimation of symptom severity, as in only 44% of stroke situations respondents would choose to call the emergency service (EMS). In the survey on 393 consecutive patients, 55% presented over 2 hours after symptom onset; major determinants were deciding to call the general practitioner first and the reaction of the first person the patient called. In phase 2, adult individuals were identified as the target of the intervention, both as potential "patients" and witnesses of stroke. The low educational level found in the patient survey called for a narrative approach in cartoon form. The family setting was chosen for the message because 42% of patients who presented within 2 hours had been advised by a family member to call EMS. To act on people's tendency to view stroke as an untreatable disease, it was decided to avoid fear-arousal appeals and use a positive message providing instructions and hope. Focus groups were used to test educational products and identify the most suitable sites for message dissemination. The IM approach allowed to develop a stroke campaign integrating theories, scientific evidence and information collected from the target population, and enabled to provide clear explanations for the reasons behind key decisions during the intervention development process. NCT01881152 . Retrospectively registered June 7 2013.

Promoting psychosocial well-being following stroke: study protocol for a randomized, controlled trial.

PubMed

Kirkevold, Marit; Kildal Bragstad, Line; Bronken, Berit A; Kvigne, Kari; Martinsen, Randi; Gabrielsen Hjelle, Ellen; Kitzmüller, Gabriele; Mangset, Margrete; Angel, Sanne; Aadal, Lena; Eriksen, Siren; Wyller, Torgeir B; Sveen, Unni

2018-04-03

Stroke is a major public health threat globally. Psychosocial well-being may be affected following stroke. Depressive symptoms, anxiety, general psychological distress and social isolation are prevalent. Approximately one third report depressive symptoms and 20% report anxiety during the first months or years after the stroke. Psychosocial difficulties may impact significantly on long-term functioning and quality of life, reduce the effects of rehabilitation services and lead to higher mortality rates. The aim of the study is to evaluate the effect of a previously developed and feasibility tested dialogue-based psychosocial intervention aimed at promoting psychosocial well-being and coping following stroke among stroke survivors with and without aphasia. The study will be conducted as a multicenter, randomized, single blind controlled trial with one intervention and one control arm. It will include a total of 330 stroke survivors randomly allocated into either an intervention group (dialogue-based intervention to promote psychosocial well-being) or a control group (usual care). Participants in the intervention group will receive eight individual sessions of supported dialogues in their homes during the first six months following an acute stroke. The primary outcome measure will be psychosocial well-being measured by the General Health Questionnaire (GHQ). Secondary outcome measures will be quality of life (SAQoL), sense of coherence (SOC), and depression (Yale). Process evaluation will be conducted in a longitudinal mixed methods study by individual qualitative interviews with 15-20 participants in the intervention and control groups, focus group interviews with the intervention personnel and data collectors, and a comprehensive analysis of implementation fidelity. The intervention described in this study protocol is based on thorough development and feasibility work, guided by the UK medical research council framework for developing and testing complex interventions. It combines classical effectiveness evaluation with a thorough process evaluation. The results from this study may inform the development of further trials aimed at promoting psychosocial well-being following stroke as well as inform the psychosocial follow up of stroke patients living at home. NCT02338869 ; registered 10/04/2014 (On-going trial).

The Stroke Riskometer™ App: Validation of a data collection tool and stroke risk predictor

PubMed Central

Parmar, Priya; Krishnamurthi, Rita; Ikram, M Arfan; Hofman, Albert; Mirza, Saira S; Varakin, Yury; Kravchenko, Michael; Piradov, Michael; Thrift, Amanda G; Norrving, Bo; Wang, Wenzhi; Mandal, Dipes Kumar; Barker-Collo, Suzanne; Sahathevan, Ramesh; Davis, Stephen; Saposnik, Gustavo; Kivipelto, Miia; Sindi, Shireen; Bornstein, Natan M; Giroud, Maurice; Béjot, Yannick; Brainin, Michael; Poulton, Richie; Narayan, K M Venkat; Correia, Manuel; Freire, António; Kokubo, Yoshihiro; Wiebers, David; Mensah, George; BinDhim, Nasser F; Barber, P Alan; Pandian, Jeyaraj Durai; Hankey, Graeme J; Mehndiratta, Man Mohan; Azhagammal, Shobhana; Ibrahim, Norlinah Mohd; Abbott, Max; Rush, Elaine; Hume, Patria; Hussein, Tasleem; Bhattacharjee, Rohit; Purohit, Mitali; Feigin, Valery L

2015-01-01

Background The greatest potential to reduce the burden of stroke is by primary prevention of first-ever stroke, which constitutes three quarters of all stroke. In addition to population-wide prevention strategies (the ‘mass’ approach), the ‘high risk’ approach aims to identify individuals at risk of stroke and to modify their risk factors, and risk, accordingly. Current methods of assessing and modifying stroke risk are difficult to access and implement by the general population, amongst whom most future strokes will arise. To help reduce the burden of stroke on individuals and the population a new app, the Stroke Riskometer™, has been developed. We aim to explore the validity of the app for predicting the risk of stroke compared with current best methods. Methods 752 stroke outcomes from a sample of 9501 individuals across three countries (New Zealand, Russia and the Netherlands) were utilized to investigate the performance of a novel stroke risk prediction tool algorithm (Stroke Riskometer™) compared with two established stroke risk score prediction algorithms (Framingham Stroke Risk Score [FSRS] and QStroke). We calculated the receiver operating characteristics (ROC) curves and area under the ROC curve (AUROC) with 95% confidence intervals, Harrels C-statistic and D-statistics for measure of discrimination, R2 statistics to indicate level of variability accounted for by each prediction algorithm, the Hosmer-Lemeshow statistic for calibration, and the sensitivity and specificity of each algorithm. Results The Stroke Riskometer™ performed well against the FSRS five-year AUROC for both males (FSRS = 75·0% (95% CI 72·3%–77·6%), Stroke Riskometer™ = 74·0(95% CI 71·3%–76·7%) and females [FSRS = 70·3% (95% CI 67·9%–72·8%, Stroke Riskometer™ = 71·5% (95% CI 69·0%–73·9%)], and better than QStroke [males – 59·7% (95% CI 57·3%–62·0%) and comparable to females = 71·1% (95% CI 69·0%–73·1%)]. Discriminative ability of all algorithms was low (C-statistic ranging from 0·51–0·56, D-statistic ranging from 0·01–0·12). Hosmer-Lemeshow illustrated that all of the predicted risk scores were not well calibrated with the observed event data (P < 0·006). Conclusions The Stroke Riskometer™ is comparable in performance for stroke prediction with FSRS and QStroke. All three algorithms performed equally poorly in predicting stroke events. The Stroke Riskometer™ will be continually developed and validated to address the need to improve the current stroke risk scoring systems to more accurately predict stroke, particularly by identifying robust ethnic/race ethnicity group and country specific risk factors. PMID:25491651

[Advances in the pathophysiology and management of infections in the acute phase of stroke].

PubMed

Salat, David; Campos, Mireia; Montaner, Joan

2012-12-15

Infection in the acute phase of stroke has been identified as an independent predictor of poor outcome, both in the short and intermediate term. Various factors raising the risk of developing an infection (exposure to multiple pathogens, disruption of the protective function of the mucous membranes and a state of relative immunosuppression) coexist during the acute phase of stroke. Several risk factors have been identified for their development (especially increasing age and stroke severity). It has been proposed that infection contributes to a worse prognosis through different mechanisms, notably the development of an inflammatory response to brain tissue (with a potential to add secondary damage to that caused by the ischemic insult). Clinical trials evaluating the prophylactic and early administration of antibiotics to reduce the incidence of infection in the acute phase of stroke have yielded inconsistent results. Immunomodulating strategies, which may provide therapeutic alternatives in the future, are currently being evaluated. Copyright © 2012 Elsevier España, S.L. All rights reserved.

Risk of Stroke Among Survivors of the September 11, 2001 World Trade Center Disaster.

PubMed

Yu, Shengchao; Alper, Howard E; Nguyen, Angela-Maithy; Brackbill, Robert M

2018-05-30

The aim of this study was to investigate the association between 9/11-related posttraumatic stress disorder (PTSD), dust cloud exposure, and subsequent development of stroke among 42,527 enrollees in the World Trade Center (WTC) Health Registry. Using four waves of longitudinal data from the WTC Health Registry surveys, we employed Cox proportional hazards regression models to assess the associations. Incidence of stroke was higher among those with PTSD or intense dust cloud exposure than those without, and it was even higher for those who had experienced both. In fully adjusted models, participants with PTSD had an increased risk of developing stroke [adjusted hazards ratio (AHR) 1.69, 95% confidence interval (95% CI) 1.42 to 2.02], as did those with intense dust exposure (AHR 1.29, 95% CI 1.09 to 1.53). We found that individuals with 9/11-related PTSD and/or intense dust exposure may have an increased risk of developing stroke.

e100 NeuroRobotic system.

PubMed

Stein, Joel

2009-01-01

Therapy incorporating the repeated practice of motor tasks has been found to enhance motor function after stroke. This type of therapy may be facilitated by robotic devices and several such devices are being developed for use in rehabilitation. The Myomo e100 NeuroRobotic system is a novel device developed to provide assistance during elbow movements in stroke survivors. The device uses surface electromyographic signals to control a powered elbow orthosis. Data from a pilot study reveals that the device can be used successfully by stroke survivors and suggests that it may be effective in helping to restore motor control after stroke. Further studies are needed to confirm these preliminary results.

Return stroke velocities and currents using a solid state silicon detector system

NASA Technical Reports Server (NTRS)

Mach, Douglas M.; Rust, W. David

1988-01-01

A small, portable device has been developed to measure return stroke velocities. With the device, velocities from 135 strokes that consist of 92 natural return strokes and 43 triggered return strokes have been analyzed. The average return stroke velocity for longer channels, greater than 500 meters, is 1.2 + or - 0.3 x 10 to the 8th m/s for both natural and triggered return strokes. For shorter channel lengths, less than 500 m, natural lightning has a statistically higher average return stroke velocity of 1.9 + or - 0.7 x 10 to the 8th m/s than triggered lightning with an average return stroke velocity of 1.4 + or - 0.4 x 10 to the 8th m/s. Using the transmission line model of the return stroke, natural lightning has a peak current distribution that is log-normal with a median value of 19 kA. Return stroke velocities and currents were determined for two distant single stroke natural positive cloud-to-ground flashes. The velocities were 1.0 and 1.7 x 10 to the 8th ms/s while the estimated peak current for each positive flash was over 125 kA.

Defining and Measuring Dysphagia Following Stroke

ERIC Educational Resources Information Center

Daniels, Stephanie K.; Schroeder, Mae Fern; DeGeorge, Pamela C.; Corey, David M.; Foundas, Anne L.; Rosenbek, John C.

2009-01-01

Purpose: To continue the development of a quantified, standard method to differentiate individuals with stroke and dysphagia from individuals without dysphagia. Method: Videofluoroscopic swallowing studies (VFSS) were completed on a group of participants with acute stroke (n = 42) and healthy age-matched individuals (n = 25). Calibrated liquid…

Polymorphisms of the lipoprotein lipase gene as genetic markers for stroke in colombian population: a case control study.

PubMed

Velásquez Pereira, Leydi Carolina; Vargas Castellanos, Clara Inés; Silva Sieger, Federico Arturo

2016-12-30

To analyze if there is an association between the presence of polymorphisms in the LPL gene (rs320, rs285 and rs328) with development of acute ischemic stroke in Colombian population. In a case control design, 133 acute ischemic stroke patients (clinical diagnosis and x-ray CT) and 269 subjects without stroke as controls were studied. PCR -RFLP technique was used to detect rs320, rs285 and rs328 polymorphisms in the LPL gene. In the present research was not found any association between any of the LPL gene polymorphism and acute ischemic stroke in the population studied; the allele and genotypic frequencies of the studied polymorphisms were similar in cases and controls and followed the Hardy-Weinberg equilibrium. The study was approved by the IRB and each subject signed the informed consent. LPL gene polymorphisms are not genetic markers for the development of stroke in the Colombian sample used.

Development of stroke-induced quadriplegia after endovascular repair of blunt aortic injury pseudoaneurysm

PubMed Central

Amoudi, Abdullah S.; Merdad, Anas A.; Makhdoom, Ahmed Q.; Jamjoom, Reda A.

2015-01-01

Endovascular repair of blunt aortic injury is now a first-line approach in management. This can warrant coverage of the left subclavian artery (LSA), which could lead to posterior strokes. In this case report, we present a severe complication of endovascular repair of a traumatic aortic aneurysm. A 53-year-old man presented with blunt aortic injury, endovascular repair was carried out where the left subclavian artery was covered. The intervention had a 100% technical success. Twelve hours later, he was discovered to have quadriplegia, a CT scan showed a large left cerebellar infarction extending to the medulla oblongata and proximal spinal cord. Strokes complicate 3% of thoracic endovascular aortic repairs, 80% of those strokes occur in patients who had their LSA’s covered. Most patients however, tolerate the coverage. Although our patient had a dominant right vertebral artery, and lacked risks for these strokes, he developed an extensive stroke that left him quadriplegic. PMID:25630782

Building a Knowledge to Action Program in Stroke Rehabilitation.

PubMed

Janzen, Shannon; McIntyre, Amanda; Richardson, Marina; Britt, Eileen; Teasell, Robert

2016-09-01

The knowledge to action (KTA) process proposed by Graham et al (2006) is a framework to facilitate the development and application of research evidence into clinical practice. The KTA process consists of the knowledge creation cycle and the action cycle. The Evidence Based Review of Stroke Rehabilitation is a foundational part of the knowledge creation cycle and has helped guide the development of best practice recommendations in stroke. The Rehabilitation Knowledge to Action Project is an audit-feedback process for the clinical implementation of best practice guidelines, which follows the action cycle. The objective of this review was to: (1) contextualize the Evidence Based Review of Stroke Rehabilitation and Rehabilitation Knowledge to Action Project within the KTA model and (2) show how this process led to improved evidence-based practice in stroke rehabilitation. Through this process, a single centre was able to change clinical practice and promote a culture that supports the use of evidence-based practices in stroke rehabilitation.

Care for post-stroke patients at Malaysian public health centres: self-reported practices of family medicine specialists.

PubMed

Abdul Aziz, Aznida F; Mohd Nordin, Nor Azlin; Abd Aziz, Noor; Abdullah, Suhazeli; Sulong, Saperi; Aljunid, Syed M

2014-03-02

Provision of post stroke care in developing countries is hampered by discoordination of services and limited access to specialised care. Albeit shortcomings, primary care continues to provide post-stroke services in less than favourable circumstances. This paper aimed to review provision of post-stroke care and related problems among Family Medicine Specialists managing public primary health care services. A semi-structured questionnaire was distributed to 121 Family Physicians servicing public funded health centres in a pilot survey focused on improving post stroke care provision at community level. The questionnaire assessed respondents background and practice details i.e. estimated stroke care burden, current service provision and opinion on service improvement. Means and frequencies described quantitative data. For qualitative data, constant comparison method was used until saturation of themes was reached. Response rate of 48.8% was obtained. For every 100 patients seen at public healthcentres each month, 2 patients have stroke. Median number of stroke patients seen per month is 5 (IQR 2-10). 57.6% of respondents estimated total stroke patients treated per year at each centre was less than 40 patients. 72.4% lacked a standard care plan although 96.6% agreed one was needed. Patients seen were: discharged from tertiary care (88.1%), shared care plan with specialists (67.8%) and patients who developed stroke during follow up at primary care (64.4%). Follow-ups were done at 8-12 weekly intervals (60.3%) with 3.4% on 'as needed' basis. Referrals ranked in order of frequency were to physiotherapy services, dietitian and speech and language pathologists in public facilities. The FMS' perceived 4 important 'needs' in managing stroke patients at primary care level; access to rehabilitation services, coordinated care between tertiary centres and primary care using multidisciplinary care approach, a standardized guideline and family and caregiver support. Post discharge stroke care guidelines and access to rehabilitation services at primary care is needed for post stroke patients residing at home in the community.

Dietary Supplementations as Neuroprotective Therapies: Focus on NT-020 Diet Benefits in a Rat Model of Stroke

PubMed Central

Kaneko, Yuji; Cortes, Lourdes; Sanberg, Cyndy; Acosta, Sandra; Bickford, Paula C.; Borlongan, Cesar V.

2012-01-01

Stroke remains the number one cause of disability in the adult population. Despite scientific progress in our understanding of stroke pathology, only one treatment (tissue plasminogen activator or tPA) is able to afford benefits but to less than 3% of ischemic stroke patients. The development of experimental dietary supplement therapeutics designed to stimulate endogenous mechanisms that confer neuroprotection is likely to open new avenues for exploring stroke therapies. The present review article evaluates the recent literature supporting the benefits of dietary supplementation for the therapy of ischemic stroke. This article focuses on discussing the medical benefits of NT-020 as an adjunct agent for stroke therapy. Based on our preliminary data, a pre-stroke treatment with dietary supplementation promotes neuroprotection by decreasing inflammation and enhancing neurogenesis. However, we recognize that a pre-stroke treatment holds weak clinical relevance. Thus, the main goal of this article is to provide information about recent data that support the assumption of natural compounds as neuroprotective and to evaluate the therapeutic effects of a dietary supplement called NT-020 as in a stroke model. We focus on a systematic assessment of practical treatment parameters so that NT-020 and other dietary supplementations can be developed as an adjunct agent for the prevention or treatment of chronic diseases. We offer rationale for determining the optimal dosage, therapeutic window, and mechanism of action of NT-020 as a dietary supplement to produce neuroprotection when administered immediately after stroke onset. We highlight our long-standing principle in championing both translational and basic science approaches in an effort to fully reveal the therapeutic potential of NT-020 as dietary supplementation in the treatment of stroke. We envision dietary supplementation as an adjunct therapy for stroke at acute, subacute, and even chronic periods. PMID:22837703

Professionals’ views on interprofessional stroke team functioning

PubMed Central

Cramm, Jane M; Nieboer, Anna P

2011-01-01

Introduction The quality of integrated stroke care depends on smooth team functioning but professionals may not always work well together. Professionals’ perspectives on the factors that influence stroke team functioning remain largely unexamined. Understanding their experiences is critical to indentifying measures to improve team functioning. The aim of this study was to identify the factors that contributed to the success of interprofessional stroke teams as perceived by team members. Methods We distributed questionnaires to professionals within 34 integrated stroke care teams at various health care facilities in 9 Dutch regions. 558 respondents (response rate: 39%) completed the questionnaire. To account for the hierarchical structure of the study design we fitted a hierarchical random-effects model. The hierarchical structure comprised 558 stroke team members (level 1) nested in 34 teams (level 2). Results Analyses showed that personal development, social well-being, interprofessional education, communication, and role understanding significantly contributed to stroke team functioning. Team-level constructs affecting interprofessional stroke team functioning were communication and role understanding. No significant relationships were found with individual-level personal autonomy and team-level cohesion. Discussion and conclusion Our findings suggest that interventions to improve team members’ social well-being, communication, and role understanding will improve teams’ performance. To further advance interprofessional team functioning, healthcare organizations should pay attention to developing professionals’ interpersonal skills and interprofessional education. PMID:23390409

Translating new knowledge into practices: reconceptualising stroke as an emergency condition

PubMed Central

Snow, Stephanie J

2013-01-01

Objectives To examine how the new concept of stroke as an emergency condition led to the development of new clinical pathways for stroke patients in Newcastle Upon Tyne, implemented through protocols which were then rapidly adopted across the UK and further afield. Methods Historical analysis using health policy documents, published papers and correspondence on stroke alongside 17 interviews with stroke clinicians and managers in the UK and the US. Results The challenges of implementation stemmed from organisational and professional barriers rather than scientific or technological difficulties. Stroke’s historical status as a non-treatable illness was a barrier to the adoption of acute treatments. Building new pathways for stroke patients by developing protocols for paramedics and emergency room staff originated as a local solution to a local problem but were taken up widely. Discussion Understanding the clinical response to the reconceptualisation of stroke as a treatable disease contributes to our understandings of the relations between clinical research and practice. These findings have implications for how we understand the translation of new knowledge into practice and its transfer across different clinical communities and settings. Protocols are shown to be a particularly valuable tool, bridging knowledge between communities and manifesting a new identity for stroke. PMID:23129788

Technique of diffusion weighted imaging and its application in stroke

NASA Astrophysics Data System (ADS)

Li, Enzhong; Tian, Jie; Han, Ying; Wang, Huifang; Li, Wu; He, Huiguang

2003-05-01

To study the application of diffusion weighted imaging and image post processing in the diagnosis of stroke, especially in acute stroke, 205 patients were examined by 1.5 T or 1.0 T MRI scanner and the images such as T1, T2 and diffusion weighted images were obtained. Image post processing was done with "3D Med System" developed by our lab to analyze data and acquire the apparent diffusion coefficient (ADC) map. In acute and subacute stage of stroke, the signal in cerebral infarction areas changed to hyperintensity in T2- and diffusion-weighted images, normal or hypointensity in T1-weighted images. In hyperacute stage, however, the signal was hyperintense just in the diffusion weighted imaes; others were normal. In the chronic stage, the signal in T1- and diffusion-weighted imaging showed hypointensity and hyperintensity in T2 weighted imaging. Because ADC declined obviously in acute and subacute stage of stroke, the lesion area was hypointensity in ADC map. With the development of the disease, ADC gradually recovered and then changed to hyperintensity in ADC map in chronic stage. Using diffusion weighted imaging and ADC mapping can make a diagnosis of stroke, especially in the hyperacute stage of stroke, and can differentiate acute and chronic stroke.

Stroke doctors: Who are we? A World Stroke Organization survey.

PubMed

Meretoja, Atte; Acciarresi, Monica; Akinyemi, Rufus O; Campbell, Bruce; Dowlatshahi, Dar; English, Coralie; Henninger, Nils; Poppe, Alexandre; Putaala, Jukka; Saini, Monica; Sato, Shoichiro; Wu, Bo; Brainin, Michael; Norrving, Bo; Davis, Stephen

2017-10-01

Background Specialist training provides skilled workforce for service delivery. Stroke medicine has evolved rapidly in the past years. No prior information exists on background or training of stroke doctors globally. Aims To describe the specialties that represent stroke doctors, their training requirements, and the scientific organizations ensuring continuous medical education. Methods The World Stroke Organization conducted an expert survey between June and November 2014 using e-mailed questionnaires. All Organization for Economic Co-operation and Development countries with >1 million population and other countries with >50 million population were included ( n = 49, total 5.6 billion inhabitants, 85% of global strokes). Two stroke experts from each selected country were surveyed, discrepancies resolved, and further information on identified stroke-specific curricula sought. Results We received responses from 48 (98%) countries. Of ischemic stroke patients, 64% were reportedly treated by neurologists, ranging from 5% in Ireland to 95% in the Netherlands. Per thousand annual strokes there were average six neurologists, ranging from 0.3 in Ethiopia to 33 in Israel. Of intracerebral hemorrhage patients, 29% were reportedly treated by neurosurgeons, ranging from 5% in Sweden to 79% in Japan, with three neurosurgeons per thousand strokes, ranging from 0.1 in Ethiopia to 24 in South Korea. Most countries had a stroke society (86%) while only 10 (21%) had a degree or subspecialty for stroke medicine. Conclusions Stroke doctor numbers, background specialties, and opportunities to specialize in stroke vary across the globe. Most countries have a scientific society to pursue advancement of stroke medicine, but few have stroke curricula.

Stroke mortality and its determinants in a resource-limited setting: A prospective cohort study in Yaounde, Cameroon.

PubMed

Nkoke, Clovis; Lekoubou, Alain; Balti, Eric; Kengne, Andre Pascal

2015-11-15

About three quarters of stroke deaths occur in developing countries including those in sub-Saharan African. Short and long-term stroke fatality data are needed for health service and policy formulation. We prospectively followed up from stroke onset, 254 patients recruited from the largest reference hospitals in Yaounde (Cameroon). Mortality and determinants were investigated using the accelerated failure time regression analysis. Stroke mortality rates at one-, six- and 12 months were respectively 23.2% (Ischemic strokes: 20.4%, hemorrhagic strokes: 26.1%, and undetermined strokes: 34.8, p=0.219), 31.5% (ischemic strokes: 31.5%, hemorrhagic strokes: 30.4%, and undetermined strokes: 34.8%, p=0.927), and 32.7% (ischemic strokes: 32.1%, hemorrhagic strokes: 30.4%, undetermined strokes: 43.5%, p=0.496). Fever, swallowing difficulties, and admission NIHSS independently predicted mortality at one month, six and 12 months. Elevated systolic blood pressure (BP) predicted mortality at one month. Elevated diastolic blood pressure was a predictor of mortality at one month in participants with hemorrhagic stroke. Low hemoglobin level on admission only predicted long term mortality. In this resource-limited setting, post-stroke mortality was high with 1 out of 5 deaths occurring at one month and up to 30% deaths at six and twelve months after the index event. Fever, stroke severity, elevated BP and anemia increased the risk of death. Our findings add to the body of evidence for the poor outcome after stroke in resource limited environments. Copyright © 2015 Elsevier B.V. All rights reserved.

MaLT - Combined Motor and Language Therapy Tool for Brain Injury Patients Using Kinect.

PubMed

Wairagkar, Maitreyee; McCrindle, Rachel; Robson, Holly; Meteyard, Lotte; Sperrin, Malcom; Smith, Andy; Pugh, Moyra

2017-03-23

The functional connectivity and structural proximity of elements of the language and motor systems result in frequent co-morbidity post brain injury. Although rehabilitation services are becoming increasingly multidisciplinary and "integrated", treatment for language and motor functions often occurs in isolation. Thus, behavioural therapies which promote neural reorganisation do not reflect the high intersystem connectivity of the neurologically intact brain. As such, there is a pressing need for rehabilitation tools which better reflect and target the impaired cognitive networks. The objective of this research is to develop a combined high dosage therapy tool for language and motor rehabilitation. The rehabilitation therapy tool developed, MaLT (Motor and Language Therapy), comprises a suite of computer games targeting both language and motor therapy that use the Kinect sensor as an interaction device. The games developed are intended for use in the home environment over prolonged periods of time. In order to track patients' engagement with the games and their rehabilitation progress, the game records patient performance data for the therapist to interrogate. MaLT incorporates Kinect-based games, a database of objects and language parameters, and a reporting tool for therapists. Games have been developed that target four major language therapy tasks involving single word comprehension, initial phoneme identification, rhyme identification and a naming task. These tasks have 8 levels each increasing in difficulty. A database of 750 objects is used to programmatically generate appropriate questions for the game, providing both targeted therapy and unique gameplay every time. The design of the games has been informed by therapists and by discussions with a Public Patient Involvement (PPI) group. Pilot MaLT trials have been conducted with three stroke survivors for the duration of 6 to 8 weeks. Patients' performance is monitored through MaLT's reporting facility presented as graphs plotted from patient game data. Performance indicators include reaction time, accuracy, number of incorrect responses and hand use. The resultant games have also been tested by the PPI with a positive response and further suggestions for future modifications made. MaLT provides a tool that innovatively combines motor and language therapy for high dosage rehabilitation in the home. It has demonstrated that motion sensor technology can be successfully combined with a language therapy task to target both upper limb and linguistic impairment in patients following brain injury. The initial studies on stroke survivors have demonstrated that the combined therapy approach is viable and the outputs of this study will inform planned larger scale future trials.

Novel Screening Tool for Stroke Using Artificial Neural Network.

PubMed

Abedi, Vida; Goyal, Nitin; Tsivgoulis, Georgios; Hosseinichimeh, Niyousha; Hontecillas, Raquel; Bassaganya-Riera, Josep; Elijovich, Lucas; Metter, Jeffrey E; Alexandrov, Anne W; Liebeskind, David S; Alexandrov, Andrei V; Zand, Ramin

2017-06-01

The timely diagnosis of stroke at the initial examination is extremely important given the disease morbidity and narrow time window for intervention. The goal of this study was to develop a supervised learning method to recognize acute cerebral ischemia (ACI) and differentiate that from stroke mimics in an emergency setting. Consecutive patients presenting to the emergency department with stroke-like symptoms, within 4.5 hours of symptoms onset, in 2 tertiary care stroke centers were randomized for inclusion in the model. We developed an artificial neural network (ANN) model. The learning algorithm was based on backpropagation. To validate the model, we used a 10-fold cross-validation method. A total of 260 patients (equal number of stroke mimics and ACIs) were enrolled for the development and validation of our ANN model. Our analysis indicated that the average sensitivity and specificity of ANN for the diagnosis of ACI based on the 10-fold cross-validation analysis was 80.0% (95% confidence interval, 71.8-86.3) and 86.2% (95% confidence interval, 78.7-91.4), respectively. The median precision of ANN for the diagnosis of ACI was 92% (95% confidence interval, 88.7-95.3). Our results show that ANN can be an effective tool for the recognition of ACI and differentiation of ACI from stroke mimics at the initial examination. © 2017 American Heart Association, Inc.

Design and implementation of visual-haptic assistive control system for virtual rehabilitation exercise and teleoperation manipulation.

PubMed

Veras, Eduardo J; De Laurentis, Kathryn J; Dubey, Rajiv

2008-01-01

This paper describes the design and implementation of a control system that integrates visual and haptic information to give assistive force feedback through a haptic controller (Omni Phantom) to the user. A sensor-based assistive function and velocity scaling program provides force feedback that helps the user complete trajectory following exercises for rehabilitation purposes. This system also incorporates a PUMA robot for teleoperation, which implements a camera and a laser range finder, controlled in real time by a PC, were implemented into the system to help the user to define the intended path to the selected target. The real-time force feedback from the remote robot to the haptic controller is made possible by using effective multithreading programming strategies in the control system design and by novel sensor integration. The sensor-based assistant function concept applied to teleoperation as well as shared control enhances the motion range and manipulation capabilities of the users executing rehabilitation exercises such as trajectory following along a sensor-based defined path. The system is modularly designed to allow for integration of different master devices and sensors. Furthermore, because this real-time system is versatile the haptic component can be used separately from the telerobotic component; in other words, one can use the haptic device for rehabilitation purposes for cases in which assistance is needed to perform tasks (e.g., stroke rehab) and also for teleoperation with force feedback and sensor assistance in either supervisory or automatic modes.

Middle cerebral artery occlusion in Macaca fascicularis: acute and chronic stroke evolution.

PubMed

D'Arceuil, Helen E; Duggan, Michael; He, Julian; Pryor, Johnny; de Crespigny, Alex

2006-04-01

An intravascular stroke model designed for magnetic resonance imaging was developed in Macaca fascicularis (M. fascicularis) to characterize serial stroke lesion evolution. This model produces a range of stroke lesion sizes which closely mimics human stroke evolution. This paper describes the care of animals undergoing this stroke procedure, the range of outcomes we experienced and the cause of mortality in this model. Anesthesia was induced with atropine and ketamine and maintained with isoflurane or propofol. Non-invasive blood pressure, oxygen saturation, heart rate, respiration rate, temperature and end tidal CO2 were monitored continuously. The stroke was created by occluding a distal branch of the middle cerebral artery. During catheter placement animals were heparinized and vasospasm was minimized using verapamil. Anesthetic induction and maintenance were smooth. Animals with small strokes showed very rapid recovery, were able to ambulate and self-feed within 2 hours of recovery. Animals with strokes of >or=4% of the hemispheric volume required lengthy observation during recovery and parenteral nutrition. Large strokes resulted in significant brain edema, herniation and brainstem compression. Intracerebral hemorrhage and or subarachnoid hemorrhage coupled with a stroke of any size was acutely fatal. In the absence of an effective acute stroke therapy, the spectrum of outcomes seen in our primate model is very similar to that observed in human stroke patients.

Twenty-Five-Year (1986-2011) Trends in the Incidence and Death Rates of Stroke Complicating Acute Myocardial Infarction.

PubMed

Hariri, Essa; Tisminetzky, Mayra; Lessard, Darleen; Yarzebski, Jorge; Gore, Joel; Goldberg, Robert

2018-05-04

The occurrence of a stroke after an acute myocardial infarction is associated with increased morbidity and mortality rates. However, limited data are available, particularly from a population-based perspective, about recent trends in the incidence and mortality rates associated with stroke complicating an acute myocardial infarction. The purpose of this study was to examine 25-year trends (1986-2011) in the incidence and in-hospital mortality rates of initial episodes of stroke complicating acute myocardial infarction. The study population consisted of 11,436 adults hospitalized with acute myocardial infarction at all 11 medical centers in central Massachusetts on a biennial basis between 1986 and 2011. In this study cohort, 159 patients (1.4%) experienced an acute first-ever stroke during hospitalization for acute myocardial infarction. The proportion of patients with acute myocardial infarction who developed a stroke increased through the 1990s but decreased slightly thereafter. Compared with patients who did not experience a stroke, those who experienced a stroke were significantly older, were more likely to be female, had a previous acute myocardial infarction, had a significant burden of comorbidities, and were more likely to have died (32.1% vs 10.8%) during their index hospitalization. Patients who developed a first stroke in the most recent study years (2003-2011) were more likely to have died during hospitalization than those hospitalized during earlier study years. Although the incidence rates of acute stroke complicating acute myocardial infarction remained relatively stable during the years under study, the in-hospital mortality rates of those experiencing a stroke have not decreased. Copyright © 2018. Published by Elsevier Inc.

Increased pulse wave velocity in patients with acute lacunar infarction doubled the risk of future ischemic stroke.

PubMed

Saji, Naoki; Murotani, Kenta; Shimizu, Hirotaka; Uehara, Toshiyuki; Kita, Yasushi; Toba, Kenji; Sakurai, Takashi

2017-04-01

The aim of this study was to determine whether pulse wave velocity (PWV), a marker of vascular endothelial impairment and arteriosclerosis, predicts future ischemic stroke in patients who developed acute lacunar infarction. Patients with a first-ever ischemic stroke due to acute lacunar infarction were enrolled in this study. An oscillometric device (Form PWV/ABI; Omron Colin, Tokyo, Japan) was used to measure brachial-ankle PWV 1 week after stroke onset. Patients were followed for at least 5 years. The main end point of the study was recurrent ischemic stroke. Event-free survival was analyzed using Kaplan-Meier plots and log-rank tests. The risk of recurrent ischemic stroke was estimated using the Cox proportional-hazards model. Of the 156 patients (61% male, mean age: 69.2±11.3 years) assessed in this study, 29 developed recurrent ischemic stroke. The median brachial-ankle PWV value was 20.4 m s -1 . Patients with high PWV values had a greater risk of recurrent ischemic stroke than patients with low PWV values (28% vs. 15%, P=0.08). Kaplan-Meier curve analysis showed that patients with high PWV values had a less favorable (that is, free of recurrent ischemic stroke) survival time (P=0.015). A multivariate Cox proportional-hazards model identified high PWV as an independent predictor of recurrent ischemic stroke after adjusting for age, sex and blood pressure (hazard ratio 2.35, 95% confidence interval, 1.02-5.70, P=0.044). In patients with acute lacunar infarction, a high PWV predicts a twofold greater risk of future ischemic stroke, independent of patient age, sex and blood pressure levels.

Substantial Progress Yet Significant Opportunity for Improvement in Stroke Care in China.

PubMed

Li, Zixiao; Wang, Chunjuan; Zhao, Xingquan; Liu, Liping; Wang, Chunxue; Li, Hao; Shen, Haipeng; Liang, Li; Bettger, Janet; Yang, Qing; Wang, David; Wang, Anxin; Pan, Yuesong; Jiang, Yong; Yang, Xiaomeng; Zhang, Changqing; Fonarow, Gregg C; Schwamm, Lee H; Hu, Bo; Peterson, Eric D; Xian, Ying; Wang, Yilong; Wang, Yongjun

2016-11-01

Stroke is a leading cause of death in China. Yet the adherence to guideline-recommended ischemic stroke performance metrics in the past decade has been previously shown to be suboptimal. Since then, several nationwide stroke quality management initiatives have been conducted in China. We sought to determine whether adherence had improved since then. Data were obtained from the 2 phases of China National Stroke Registries, which included 131 hospitals (12 173 patients with acute ischemic stroke) in China National Stroke Registries phase 1 from 2007 to 2008 versus 219 hospitals (19 604 patients) in China National Stroke Registries phase 2 from 2012 to 2013. Multiple regression models were developed to evaluate the difference in adherence to performance measure between the 2 study periods. The overall quality of care has improved over time, as reflected by the higher composite score of 0.76 in 2012 to 2013 versus 0.63 in 2007 to 2008. Nine of 13 individual performance metrics improved. However, there were no significant improvements in the rates of intravenous thrombolytic therapy and anticoagulation for atrial fibrillation. After multivariate analysis, there remained a significant 1.17-fold (95% confidence interval, 1.14-1.21) increase in the odds of delivering evidence-based performance metrics in the more recent time periods versus older data. The performance metrics with the most significantly increased odds included stroke education, dysphagia screening, smoking cessation, and antithrombotics at discharge. Adherence to stroke performance metrics has increased over time, but significant opportunities remain for further improvement. Continuous stroke quality improvement program should be developed as a national priority in China. © 2016 American Heart Association, Inc.

Characteristics of Patent Foramen Ovale Associated with Cryptogenic Stroke: A Biplane Transesophageal Echocardiography Study

NASA Technical Reports Server (NTRS)

Homma, S.; DiTullio, M. R.; Sacco, R. L.; Mihalatos, D..; LiMandri, G.; Mohr, J. P.

1994-01-01

Patent foramen ovale is associated with ischemic stroke in patients without a clearly identifiable etiology for stroke (cryptogenic stroke). Paradoxical embolization is thought to be a potential mechanism. However, patent foramen ovale is also found in patients with known cause of stroke. Therefore, using contrast transesophageal echocardiography, we characterized the patent foramen ovale in cryptogenic stroke patients to assess morphological factors that may contribute to paradoxical embolization. Methods: Contrast transesophageal echocardiographic studies of 74 consecutive patients referred for ischemic stroke were reviewed. Twenty-three patients with patent foramen ovale were identified. These patients were classified as having strokes of determined origin or cryptogenic strokes according to criteria developed for the Stroke Data Bank of the National Institute of Neurological Disorders and Stroke. Separation of septum primum from secundum and the number of microbubbles appearing in left atrium were then quantitated. These parameters were compared between patients with cryptogenic stroke and those with known cause of stroke. Results: The patent foramen ovale dimension was significantly larger in patients with cryptogenic stroke compared with patients with an identifiable cause of stroke (2.1+/-1.7 mm versus 057+/-0.78 mm [mean+/-SD]; P<.01). The number of microbubbles was also greater in patients with cryptogenic stroke compared with patients with an identifiable cause of stroke (13.9+/-10.7 versus 1.62+/-0.8 [mean+/-SD]; P<.0005). Conclusions: Patients with cryptogenic stroke have larger patent foramen ovale with more extensive right-to-left inter-atrial shunting than patients with stroke of determined cause. Transesophageal echocardiographically identifiable characteristics of patent foramen ovale may be important in defining the clinical significance of individual patent foramina.

77 FR 9731 - Rehabilitation Research and Development Service Scientific Merit Review Board; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-17

... Disease. March 6-7--Brain Injury: Traumatic Brain Injury (TBI) and Stroke; Musculoskeletal/Orthopedic... Cord Injury. March 13-14--Brain Injury: TBI and Stroke; Career Development Award Program; Psychological...

Interactive Bio-feedback Therapy Using Hybrid Assistive Limbs for Motor Recovery after Stroke: Current Practice and Future Perspectives

PubMed Central

MORISHITA, Takashi; INOUE, Tooru

2016-01-01

Interactive bio-feedback (iBF) was initially developed for the rehabilitation of motor function in patients with neurological disorders, and subsequently yielded the development of the hybrid assistive limb (HAL). Here, we provide a review of the theory underlying HAL treatment as well as our clinical experience and recommendations for future clinical studies using HAL in acute stroke patients. We performed a PubMed-based literature search, a retrospective data review of our acute stroke case series, and included a sample case report of our findings. Given past animal studies and functional imaging results, iBF therapy using the HAL in the acute phase of stroke seems an appropriate approach for preventing learned non-use and interhemispheric excitation imbalances. iBF therapy may furthermore promote appropriate neuronal network reorganization. Based on experiences in our stroke center, HAL rehabilitation is a safe and effective treatment modality for recovering motor impairments after acute stroke, and allows the design of tailored rehabilitation programs for individual patients. iBF therapy through the HAL system seems to be an effective and promising approach to stroke rehabilitation; however, the superiority of this treatment to conventional rehabilitation remains unclear. Further clinical studies are warranted. Additionally, the formation of a patient registry will permit a meta-analysis of HAL cases and address the problems associated with a controlled trial (e.g., the heterogeneity of an acute stroke cohort). The development of robotic engineering will improve the efficacy of HAL rehabilitation and has the potential to standardize patient rehabilitation practice. PMID:27616320

Clinical Manifestations, Outcomes, and Etiologies of Perinatal Stroke in Taiwan: Comparisons between Ischemic, and Hemorrhagic Stroke Based on 10-year Experience in A Single Institute.

PubMed

Lee, Chien-Chung; Lin, Jainn-Jim; Lin, Kuang-Lin; Lim, Wai-Ho; Hsu, Kai-Hsiang; Hsu, Jen-Fu; Fu, Ren-Huei; Chiang, Ming-Chou; Chu, Shih-Ming; Lien, Reyin

2017-06-01

Perinatal stroke is a common cause of established neurological sequelae. Although several risk factors have been identified, many questions regarding causes and clinical outcomes remain unanswered. This study investigated the clinical manifestations and outcomes of perinatal stroke and identified its etiologies in Taiwan. We searched the reports of head magnetic resonance imaging and computed tomography performed between January 2003 and December 2012. The medical records of enrolled infants with perinatal stroke were also reviewed. Thirty infants with perinatal stroke were identified; 10 infants had perinatal arterial ischemic stroke (PAIS) and 20 had perinatal hemorrhagic stroke (PHS). Neonatal seizure was the most common manifestation and presented in 40% of infants with PAIS and 50% of infants with PHS. All survivors with PAIS and 77% of the surviving infants with PHS developed neurological sequelae. Acute seizure manifestation was associated with poststroke epilepsy in infants with PHS but not in infants with PAIS (86% vs. 0%, p=0.005). PAIS was mostly caused by dysfunctional hemostasis (20%) and embolism (20%), whereas PHS was mostly attributable to birth asphyxia (30%). Perinatal stroke is associated with high mortality and morbidity rates in infants. Clinically, it can be difficult to distinguish PAIS and PHS. One should keep a high level of suspicion, especially for PHS, if infants develop unexplained seizure, cyanosis, conscious change, anemia, and/or thrombocytopenia. A systematic diagnostic approach is helpful in identifying the etiologies of perinatal stroke. Copyright © 2016. Published by Elsevier B.V.

Computer Games as Therapy for Persons with Stroke.

PubMed

Lauterbach, Sarah A; Foreman, Matt H; Engsberg, Jack R

2013-02-01

Stroke affects approximately 800,000 individuals each year, with 65% having residual impairments. Studies have demonstrated that mass practice leads to regaining motor function in affected extremities; however, traditional therapy does not include the repetitions needed for this recovery. Videogames have been shown to be good motivators to complete repetitions. Advances in technology and low-cost hardware bring new opportunities to use computer games during stroke therapy. This study examined the use of the Microsoft (Redmond, WA) Kinect™ and Flexible Action and Articulated Skeleton Toolkit (FAAST) software as a therapy tool to play existing free computer games on the Internet. Three participants attended a 1-hour session where they played two games with upper extremity movements as game controls. Video was taken for analysis of movement repetitions, and questions were answered about participant history and their perceptions of the games. Participants remained engaged through both games; regardless of previous computer use all participants successfully played two games. Five minutes of game play averaged 34 repetitions of the affected extremity. The Intrinsic Motivation Inventory showed a high level of satisfaction in two of the three participants. The Kinect Sensor with the FAAST software has the potential to be an economical tool to be used alongside traditional therapy to increase the number of repetitions completed in a motivating and engaging way for clients.

"FIND Technology": investigating the feasibility, efficacy and safety of controller-free interactive digital rehabilitation technology in an inpatient stroke population: study protocol for a randomized controlled trial.

PubMed

Bird, M L; Cannell, J; Callisaya, M L; Moles, E; Rathjen, A; Lane, K; Tyson, A; Smith, S

2016-04-16

Stroke results in significant disability, which can be reduced by physical rehabilitation. High levels of repetition and activity are required in rehabilitation, but patients are typically sedentary. Using clinically relevant and fun computer games may be one way to achieve increased activity in rehabilitation. A single-blind randomized controlled trial will be conducted to evaluate the feasibility, efficacy and safety of novel stroke-specific rehabilitation software. This software uses controller-free client interaction and inertial motion sensors. Elements of feasibility include recruitment into the trial, ongoing participation (adherence and dropout), perceived benefit, enjoyment and ease of use of the games. Efficacy will be determined by measuring activity and using upper-limb tasks as well as measures of balance and mobility. The hypothesis that the intervention group will have increased levels of physical activity within rehabilitation and improved physical outcomes compared with the control group will be tested. Results from this study will provide a basis for discussion of feasibility of this interactive video technological solution in an inpatient situation. Differences in activity levels between groups will be the primary measure of efficacy. It will also provide data on measures of upper-limb function, balance and mobility. ACTRN12614000427673 . Prospectively registered 17 April 2014.

Lower-Limb Rehabilitation Robot Design

NASA Astrophysics Data System (ADS)

Bouhabba, E. M.; Shafie, A. A.; Khan, M. R.; Ariffin, K.

2013-12-01

It is a general assumption that robotics will play an important role in therapy activities within rehabilitation treatment. In the last decade, the interest in the field has grown exponentially mainly due to the initial success of the early systems and the growing demand caused by increasing numbers of stroke patients and their associate rehabilitation costs. As a result, robot therapy systems have been developed worldwide for training of both the upper and lower extremities. This paper investigates and proposes a lower-limb rehabilitation robot that is used to help patients with lower-limb paralysis to improve and resume physical functions. The proposed rehabilitation robot features three rotary joints forced by electric motors providing linear motions. The paper covers mechanism design and optimization, kinematics analysis, trajectory planning, wearable sensors, and the control system design. The design and control system demonstrate that the proposed rehabilitation robot is safe and reliable with the effective design and better kinematic performance.

A solid state lightning propagation speed sensor

NASA Technical Reports Server (NTRS)

Mach, Douglas M.; Rust, W. David

1989-01-01

A device to measure the propagation speeds of cloud-to-ground lightning has been developed. The lightning propagation speed (LPS) device consists of eight solid state silicon photodetectors mounted behind precision horizontal slits in the focal plane of a 50-mm lens on a 35-mm camera. Although the LPS device produces results similar to those obtained from a streaking camera, the LPS device has the advantages of smaller size, lower cost, mobile use, and easier data collection and analysis. The maximum accuracy for the LPS is 0.2 microsec, compared with about 0.8 microsecs for the streaking camera. It is found that the return stroke propagation speed for triggered lightning is different than that for natural lightning if measurements are taken over channel segments less than 500 m. It is suggested that there are no significant differences between the propagation speeds of positive and negative flashes. Also, differences between natural and triggered dart leaders are discussed.

An electromechanical attenuator/actuator for Space Station docking

NASA Technical Reports Server (NTRS)

Stokes, Lebarian; Glenn, Dean; Carroll, Monty B.

1987-01-01

The development of a docking system for aerospace vehicles has identified the need for reusable and variably controlled attenuators/actuators for energy absorption and compliance. One approach to providing both the attenuator and the actuator functions is by way of an electromechanical attenuator/actuator (EMAA) as opposed to a hydraulic system. The use of the electromechanical devices is considered to be more suitable for a space environment because of the absence of contamination from hydraulic fluid leaks and because of the cost effectiveness of maintenance. A smart EMAA that uses range/rate/attitude sensor information to preadjust a docking interface to eliminate misalignments and to minimize contact and stroking forces is described. A prototype EMAA was fabricated and is being tested and evaluated. Results of preliminary testing and analysis already performed have established confidence that this concept is feasible and will provide the desired reliability and low maintenance for repetitive long term operation typical of Space Station requirements.

Sonochemically Fabricated Microelectrode Arrays for Use as Sensing Platforms

PubMed Central

Collyer, Stuart D.; Davis, Frank; Higson, Séamus P.J.

2010-01-01

The development, manufacture, modification and subsequent utilisation of sonochemically-formed microelectrode arrays is described for a range of applications. Initial fabrication of the sensing platform utilises ultrasonic ablation of electrochemically insulating polymers deposited upon conductive carbon substrates, forming an array of up to 70,000 microelectrode pores cm−2. Electrochemical and optical analyses using these arrays, their enhanced signal response and stir-independence area are all discussed. The growth of conducting polymeric “mushroom” protrusion arrays with entrapped biological entities, thereby forming biosensors is detailed. The simplicity and inexpensiveness of this approach, lending itself ideally to mass fabrication coupled with unrivalled sensitivity and stir independence makes commercial viability of this process a reality. Application of microelectrode arrays as functional components within sensors include devices for detection of chlorine, glucose, ethanol and pesticides. Immunosensors based on microelectrode arrays are described within this monograph for antigens associated with prostate cancer and transient ischemic attacks (strokes). PMID:22399926

Bio-logging of physiological parameters in higher marine vertebrates

NASA Astrophysics Data System (ADS)

Ponganis, Paul J.

2007-02-01

Bio-logging of physiological parameters in higher marine vertebrates had its origins in the field of bio-telemetry in the 1960s and 1970s. The development of microprocessor technology allowed its first application to bio-logging investigations of Weddell seal diving physiology in the early 1980s. Since that time, with the use of increased memory capacity, new sensor technology, and novel data processing techniques, investigators have examined heart rate, temperature, swim speed, stroke frequency, stomach function (gastric pH and motility), heat flux, muscle oxygenation, respiratory rate, diving air volume, and oxygen partial pressure (P) during diving. Swim speed, heart rate, and body temperature have been the most commonly studied parameters. Bio-logging investigation of pressure effects has only been conducted with the use of blood samplers and nitrogen analyses on animals diving at isolated dive holes. The advantages/disadvantages and limitations of recording techniques, probe placement, calibration techniques, and study conditions are reviewed.

Stroke and long-term exposure to outdoor air pollution from nitrogen dioxide: a cohort study.

PubMed

Andersen, Zorana J; Kristiansen, Luise C; Andersen, Klaus K; Olsen, Tom S; Hvidberg, Martin; Jensen, Steen S; Ketzel, Matthias; Loft, Steffen; Sørensen, Mette; Tjønneland, Anne; Overvad, Kim; Raaschou-Nielsen, Ole

2012-02-01

Years of exposure to tobacco smoke substantially increase the risk for stroke. Whether long-term exposure to outdoor air pollution can lead to stroke is not yet established. We examined the association between long-term exposure to traffic-related air pollution and incident and fatal stroke in a prospective cohort study. We followed 57,053 participants of the Danish Diet, Cancer and Health cohort in the Hospital Discharge Register for the first-ever hospital admission for stroke (incident stroke) between baseline (1993-1997) and 2006 and defined fatal strokes as death within 30 days of admission. We associated the estimated mean levels of nitrogen dioxide at residential addresses since 1971 to incident and fatal stroke by Cox regression analyses and examined the effects by stroke subtypes: ischemic, hemorrhagic, and nonspecified stroke. Over a mean follow-up of 9.8 years of 52,215 eligible subjects, there were 1984 (3.8%) first-ever (incident) hospital admissions for stroke of whom 142 (7.2%) died within 30 days. We detected borderline significant associations between mean nitrogen dioxide levels at residence since 1971 and incident stroke (hazard ratio, 1.05; 95% CI, 0.99-1.11, per interquartile range increase) and stroke hospitalization followed by death within 30 days (1.22; 1.00-1.50). The associations were strongest for nonspecified and ischemic strokes, whereas no association was detected with hemorrhagic stroke. Long-term exposure to traffic-related air pollution may contribute to the development of ischemic but not hemorrhagic stroke, especially severe ischemic strokes leading to death within 30 days.

Relationship between QT Interval Dispersion in acute stroke and stroke prognosis: A Systematic Review

PubMed Central

Lederman, Yitzchok S.; Balucani, Clotilde; Lazar, Jason; Steinberg, Leah; Gugger, James; Levine, Steven R.

2014-01-01

Background QT dispersion (QTd) has been proposed as an indirect ECG measure of heterogeneity of ventricular repolarization. The predictive value of QTd in acute stroke remains controversial. We aimed to clarify the relationship between QTd and acute stroke and stroke prognosis. Methods A systematic review of the literature was performed using pre-specified medical subjects heading (MeSH) terms, Boolean logic and the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Eligible studies (a) included ischemic or hemorrhagic stroke and (b) provided QTd measurements. Results Two independent reviewers identified 553 publications. Sixteen articles were included in the final analysis. There were a total of 888 stroke patients: 59% ischemic and 41% hemorrhagic. There was considerable heterogeneity in study design, stroke subtypes, ECG assessment-time, control groups and comparison groups. Nine studies reported a significant association between acute stroke and baseline QTd. Two studies reported that QTd increases are specifically related to hemorrhagic strokes, involvement of the insular cortex, right-side lesions, larger strokes, and increases in 3, 4-dihydroxyphenylethylene glycol in hemorrhagic stroke. Three studies reported QTd to be an independent predictor of stroke mortality. One study each reported increases in QTd in stroke patients who developed ventricular arrhythmias and cardiorespiratory compromise. Conclusions There are few well-designed studies and considerable variability in study design in addressing the significance of QTd in acute stroke. Available data suggest that stroke is likely to be associated with increased QTd. While some evidence suggests a possible prognostic role of QTd in stroke, larger and well-designed studies need to confirm these findings. PMID:25282188

Peer education for secondary stroke prevention in inner-city minorities: design and methods of the prevent recurrence of all inner-city strokes through education randomized controlled trial.

PubMed

Goldfinger, Judith Z; Kronish, Ian M; Fei, Kezhen; Graciani, Albert; Rosenfeld, Peri; Lorig, Kate; Horowitz, Carol R

2012-09-01

The highest risk for stroke is among survivors of strokes or transient ischemic attacks (TIA). However, use of proven-effective cardiovascular medications to control stroke risk is suboptimal, particularly among the Black and Latino populations disproportionately impacted by stroke. A partnership of Harlem and Bronx community representatives, stroke survivors, researchers, clinicians, outreach workers and patient educators used community-based participatory research to conceive and develop the Prevent Recurrence of All Inner-city Strokes through Education (PRAISE) trial. Using data from focus groups with stroke survivors, they tailored a peer-led, community-based chronic disease self-management program to address stroke risk factors. PRAISE will test, in a randomized controlled trial, whether this stroke education intervention improves blood pressure control and a composite outcome of blood pressure control, lipid control, and use of antithrombotic medications. Of the 582 survivors of stroke and TIA enrolled thus far, 81% are Black or Latino and 56% have an annual income less than $15,000. Many (33%) do not have blood pressures in the target range, and most (66%) do not have control of all three major stroke risk factors. Rates of stroke recurrence risk factors remain suboptimal in the high risk, urban, predominantly minority communities studied. With a community-partnered approach, PRAISE has recruited a large number of stroke and TIA survivors to date, and may prove successful in engaging those at highest risk for stroke and reducing disparities in stroke outcomes in inner-city communities. Copyright © 2012 Elsevier Inc. All rights reserved.

Strokes after cardioversion of atrial fibrillation--The FibStroke study.

PubMed

Palomäki, Antti; Mustonen, Pirjo; Hartikainen, Juha E K; Nuotio, Ilpo; Kiviniemi, Tuomas; Ylitalo, Antti; Hartikainen, Päivi; Lehtola, Heidi; Luite, Riho; Airaksinen, K E Juhani

2016-01-15

Cardioversion of atrial fibrillation (AF) is associated with an increased risk for stroke. We identified all cardioversions during the 30 days preceding stroke or transient ischemic attack (TIA) in patients with a previously diagnosed AF, and sought to assess the characteristics of cardioversions leading to stroke or TIA. FibStroke is a cross-sectional observational multicenter registry that included AF patients with an ischemic stroke or intracranial bleed identified from a discharge registry of four Finnish hospitals. In total 3677 consecutive AF patients suffered 3252 strokes and 956 TIA episodes during 2003–2012. This pre-specified analysis focused on the 1644 events that occurred to patients with paroxysmal or persistent AF at the time of stroke/TIA. A total of 78 strokes and 22 TIA episodes were preceded by a cardioversion. Post-cardioversion strokes accounted for 6.4% of strokes in patients with paroxysmal/persistent AF. Of the 100 cardioversions leading to an ischemic event, 77 were acute and 23 were elective, 63 events occurred in patients not using anticoagulation, and 5 patients had periprocedural INR < 2. Importantly, 21 patients were in low risk of stroke, i.e. CHA2DS2-VASc score < 2. The median delay from cardioversion to event was 2 days. All nine patients who after an unsuccessful cardioversion developed a stroke had a spontaneous cardioversion prior to stroke. Every sixteenth stroke of patients with paroxysmal/persistent AF is preceded by a cardioversion. Most post-cardioversion strokes occur in patients not using oral anticoagulation before cardioversion of acute AF.

Sensor probes and phantoms for advanced transcranial magnetic stimulation system developments

NASA Astrophysics Data System (ADS)

Meng, Qinglei; Patel, Prashil; Trivedi, Sudhir; Du, Xiaoming; Hong, Elliot; Choa, Fow-Sen

2015-05-01

Transcranial magnetic stimulation (TMS) has become one of the most widely used noninvasive method for brain tissue stimulation and has been used as a treatment tool for various neurological and psychiatric disorders including migraine, stroke, Parkinson's disease, dystonia, tinnitus and depression. In the process of developing advanced TMS deep brain stimulation tools, we need first to develop field measurement devices like sensory probes and brain phantoms, which can be used to calibrate the TMS systems. Currently there are commercially available DC magnetic or electric filed measurement sensors, but there is no instrument to measure transient fields. In our study, we used a commercial figure-8 shaped TMS coil to generate transient magnetic field and followed induced field and current. The coil was driven by power amplified signal from a pulse generator with tunable pulse rate, amplitude, and duration. In order to obtain a 3D plot of induced vector electric field, many types of probes were designed to detect single component of electric-field vectors along x, y and z axis in the space around TMS coil. We found that resistor probes has an optimized signal-to-noise ratio (SNR) near 3k ohm but it signal output is too weak compared with other techniques. We also found that inductor probes can have very high output for Curl E measurement, but it is not the E-field distribution we are interested in. Probes with electrical wire wrapped around iron coil can directly measure induced E-field with high sensitivity, which matched computer simulation results.

SQUID: sensorized shirt with smartphone interface for exercise monitoring and home rehabilitation.

PubMed

Farjadian, Amir B; Sivak, Mark L; Mavroidis, Constantinos

2013-06-01

Stroke is a leading cause of serious long-term disability in the United States. There is a need for new technological adjuncts to expedite patients' scheduled discharge from hospital and pursue rehabilitation procedure at home. SQUID is a low-cost, smart shirt that incorporates a six-channel electromyography (EMG) and heart rate data acquisition module to deliver objective audiovisual and haptic biofeedback to the patient. The sensorized shirt is interfaced with a smartphone application, for the subject's usage at home, as well as the online database, for the therapist's remote supervision from hospital. A single healthy subject was recruited to investigate the system functionality during improperly performed exercise. The system can potentially be used in automated, remote monitoring of variety of physical therapy exercises, rooted in strength or coordination training of specific muscle groups.

Topologically Optimized Nano-Positioning Stage Integrating with a Capacitive Comb Sensor.

PubMed

Chen, Tao; Wang, Yaqiong; Liu, Huicong; Yang, Zhan; Wang, Pengbo; Sun, Lining

2017-01-28

Nano-positioning technology has been widely used in many fields, such as microelectronics, optical engineering, and micro manufacturing. This paper presents a one-dimensional (1D) nano-positioning system, adopting a piezoelectric ceramic (PZT) actuator and a multi-objective topological optimal structure. The combination of a nano-positioning stage and a feedback capacitive comb sensor has been achieved. In order to obtain better performance, a wedge-shaped structure is used to apply the precise pre-tension for the piezoelectric ceramics. Through finite element analysis and experimental verification, better static performance and smaller kinetic coupling are achieved. The output displacement of the system achieves a long-stroke of up to 14.7 μm and high-resolution of less than 3 nm. It provides a flexible and efficient way in the design and optimization of the nano-positioning system.

Topologically Optimized Nano-Positioning Stage Integrating with a Capacitive Comb Sensor

PubMed Central

Chen, Tao; Wang, Yaqiong; Liu, Huicong; Yang, Zhan; Wang, Pengbo; Sun, Lining

2017-01-01

Nano-positioning technology has been widely used in many fields, such as microelectronics, optical engineering, and micro manufacturing. This paper presents a one-dimensional (1D) nano-positioning system, adopting a piezoelectric ceramic (PZT) actuator and a multi-objective topological optimal structure. The combination of a nano-positioning stage and a feedback capacitive comb sensor has been achieved. In order to obtain better performance, a wedge-shaped structure is used to apply the precise pre-tension for the piezoelectric ceramics. Through finite element analysis and experimental verification, better static performance and smaller kinetic coupling are achieved. The output displacement of the system achieves a long-stroke of up to 14.7 μm and high-resolution of less than 3 nm. It provides a flexible and efficient way in the design and optimization of the nano-positioning system. PMID:28134854

Regression of stroke-like lesions in MELAS-syndrome after seizure control.

PubMed

Finsterer, Josef; Barton, Peter

2010-12-01

There are some indications that seizure activity promotes the development of stroke-like episodes, or vice versa, in patients with mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome or other syndromic mitochondrial disorders. A 41-year-old Caucasian female with MELAS syndrome, presenting with short stature, microcytic anaemia, increased blood-sedimentation rate, myopathy, hyper-gammaglobulinaemia, an iron-metabolism defect, migraine-like headaches, and stroke-like episodes, developed complex partial and generalised seizures at age 32 years. Valproic acid was ineffective but after switching to lamotrigine and lorazepam, she became seizure-free for five years and stroke-like episodes did not recur. Cerebral MRI initially showed enhanced gyral thickening and a non-enhanced T2-hyperintensity over the left parieto-temporo-occipital white matter and cortex and enhanced caudate heads. After two years without seizures, the non-enhanced hyperintense parieto-temporo-occipital lesion had disappeared, being attributed to consequent seizure control. The caudate heads, however, remained hyperintense throughout the observational period. This case indicates that adequate seizure control in a patient with MELAS syndrome may prevent the recurrence of stroke-like episodes and may result in the disappearance of stroke-like lesions on MRI.

Absolute position calculation for a desktop mobile rehabilitation robot based on three optical mouse sensors.

PubMed

Zabaleta, Haritz; Valencia, David; Perry, Joel; Veneman, Jan; Keller, Thierry

2011-01-01

ArmAssist is a wireless robot for post stroke upper limb rehabilitation. Knowing the position of the arm is essential for any rehabilitation device. In this paper, we describe a method based on an artificial landmark navigation system. The navigation system uses three optical mouse sensors. This enables the building of a cheap but reliable position sensor. Two of the sensors are the data source for odometry calculations, and the third optical mouse sensor takes very low resolution pictures of a custom designed mat. These pictures are processed by an optical symbol recognition algorithm which will estimate the orientation of the robot and recognize the landmarks placed on the mat. The data fusion strategy is described to detect the misclassifications of the landmarks in order to fuse only reliable information. The orientation given by the optical symbol recognition (OSR) algorithm is used to improve significantly the odometry and the recognition of the landmarks is used to reference the odometry to a absolute coordinate system. The system was tested using a 3D motion capture system. With the actual mat configuration, in a field of motion of 710 × 450 mm, the maximum error in position estimation was 49.61 mm with an average error of 36.70 ± 22.50 mm. The average test duration was 36.5 seconds and the average path length was 4173 mm.

Assessing the Cognitive Regulation of Emotion in Depressed Stroke Patients

ERIC Educational Resources Information Center

Turner, Margaret A.; Andrewes, David G.

2010-01-01

This study evaluated the psychometric properties of a simple scale for measuring positive interpersonal attitudes of depressed stroke patients, with regard to their cognitive limitations. Two versions of the Attitudes Towards Relationships Scale were developed and administered to depressed stroke (n = 48) and control rheumatic/orthopaedic (n = 45)…

Teach Your Child Badminton.

ERIC Educational Resources Information Center

Downey, Jake

This illustrated guide provides basic knowledge that will enable parents to teach their children how to play badminton. Strokes are described functionally--how the player performs the stroke is a matter for individual interpretation. Each lesson is connected to the next in such a way as to encourage learning of strokes and skill development.…

Acute effect of ambient air pollution on stroke mortality in the China air pollution and health effects study.

PubMed

Chen, Renjie; Zhang, Yuhao; Yang, Chunxue; Zhao, Zhuohui; Xu, Xiaohui; Kan, Haidong

2013-04-01

There have been no multicity studies on the acute effects of air pollution on stroke mortality in China. This study was undertaken to examine the associations between daily stroke mortality and outdoor air pollution (particulate matter <10 μm in aerodynamic diameter, sulfur dioxide, and nitrogen dioxide) in 8 Chinese cities. We used Poisson regression models with natural spline-smoothing functions to adjust for long-term and seasonal trends, as well as other time-varying covariates. We applied 2-stage Bayesian hierarchical statistical models to estimate city-specific and national average associations of air pollution with daily stroke mortality. Air pollution was associated with daily stroke mortality in 8 Chinese cities. In the combined analysis, an increase of 10 μg/m(3) of 2-day moving average concentrations of particulate matter <10 μm in aerodynamic diameter, sulfur dioxide, and nitrogen dioxide corresponded to 0.54% (95% posterior intervals, 0.28-0.81), 0.88% (95% posterior intervals, 0.54-1.22), and 1.47% (95% posterior intervals, 0.88-2.06) increase of stroke mortality, respectively. The concentration-response curves indicated linear nonthreshold associations between air pollution and risk of stroke mortality. To our knowledge, this is the first multicity study in China, or even in other developing countries, to report the acute effect of air pollution on stroke mortality. Our results contribute to very limited data on the effect of air pollution on stroke for high-exposure settings typical in developing countries.

The Reliability and Validity of the Japanese Version of the Stroke Impact Scale Version 3.0.

PubMed

Ochi, Mitsuhiro; Ohashi, Hiroshi; Hachisuka, Kenji; Saeki, Satoru

It is important to evaluate body functions and structures, activity, and participation in stroke rehabilitation. The Stroke Impact Scale (SIS), a new stroke-specific self-report measure that was developed by Duncan et al, is widely used to measure multidimensional consequences about health-related quality of life. The SIS version 3.0 includes 9 domains (strength, hand function, activity of daily living and instrumental activity of daily living, mobility, communication, emotion, memory and thinking, participation, and recovery). Patients are asked to make a percentage rating of their recovery since their stroke on a visual analog scale of 0 to 100 for the stroke recovery domain. Each item in the 8 domains other than stroke recovery are scored in a range of 1 to 5 as a raw score and calculated using the manual to a final score. We developed a Japanese version of the SIS version 3.0 and assessed its reliability and validity in 32 chronic stroke survivors. The internal consistency (Cronbach's α < 0.70) was satisfactory. The test-retest reliability (ICC, 0.86 to 0.96) was also satisfactory. Regarding convergent validity, a significant correlation (Spearman's correlation coefficient, P < 0.05) was found between the SIS physical domain score and Brunnstrom stage (r, 0.49 to 0.53) and short form 8 (r = 0.82). The Japanese version of the SIS version 3.0 is valid, reliable, and clinically useful for stroke survivors.

Stroke injury, cognitive impairment and vascular dementia☆

PubMed Central

Kalaria, Raj N.; Akinyemi, Rufus; Ihara, Masafumi

2016-01-01

The global burden of ischaemic strokes is almost 4-fold greater than haemorrhagic strokes. Current evidence suggests that 25–30% of ischaemic stroke survivors develop immediate or delayed vascular cognitive impairment (VCI) or vascular dementia (VaD). Dementia after stroke injury may encompass all types of cognitive disorders. States of cognitive dysfunction before the index stroke are described under the umbrella of pre-stroke dementia, which may entail vascular changes as well as insidious neurodegenerative processes. Risk factors for cognitive impairment and dementia after stroke are multifactorial including older age, family history, genetic variants, low educational status, vascular comorbidities, prior transient ischaemic attack or recurrent stroke and depressive illness. Neuroimaging determinants of dementia after stroke comprise silent brain infarcts, white matter changes, lacunar infarcts and medial temporal lobe atrophy. Until recently, the neuropathology of dementia after stroke was poorly defined. Most of post-stroke dementia is consistent with VaD involving multiple substrates. Microinfarction, microvascular changes related to blood–brain barrier damage, focal neuronal atrophy and low burden of co-existing neurodegenerative pathology appear key substrates of dementia after stroke injury. The elucidation of mechanisms of dementia after stroke injury will enable establishment of effective strategy for symptomatic relief and prevention. Controlling vascular disease risk factors is essential to reduce the burden of cognitive dysfunction after stroke. This article is part of a Special Issue entitled: Vascular Contributions to Cognitive Impairment and Dementia edited by M. Paul Murphy, Roderick A. Corriveau and Donna M. Wilcock. PMID:26806700

Why a polysomnogram should become part of the diagnostic evaluation of stroke and transient ischemic attack.

PubMed

Grigg-Damberger, Madeleine

2006-02-01

Neurologists need to recognize, diagnose, and treat obstructive sleep apnea (OSA) in patients with stroke or transient ischemic attack (TIA). Increasing medical evidence suggests that OSA is an independent risk factor for stroke and TIA. Stroke (or TIA) is more likely a cause, rather than a consequence, of OSA because PSG studies have shown: 1) apneas in stroke are typically obstructive, not central or Cheyne-Stokes in type; 2) apneas are just as frequent and severe in patients with either TIA or stroke; 3) OSA severity is not influenced by the acuteness or location of the stroke; 4) untreated OSA patients have more strokes, stroke morbidity, and mortality than those who are treated. OSA alone can induce hypertension, especially in younger men. A causal relationship has recently been demonstrated between OSA and hypertension. A distinctive feature of OSA-induced hypertension is loss of the normal nighttime fall in blood pressure ("nondippers"). Data from the Sleep Heart Health Study showed a dose-response association between OSA severity and the presence of hypertension 4 years later. Hypertension or ischemic heart disease usually develops in untreated patients with OSA over time without particular worsening of OSA. Studies have shown sleep itself is not a risk factor for stroke because most stroke and TIAs begin between 6 am and noon, while the individual is awake. However, OSA promptly be considered in stroke beginning during sleep because 88% of strokes that develop during sleep occur in "nondippers." Premature death in OSA patients is most often cardiovascular, but occurs while the patients are awake. The risk of myocardial infarction is increased 20-fold in untreated OSA. Treating OSA patients with continuous positive airway pressure can prevent or improve hypertension, reduce abnormal elevations of inflammatory cytokines and adhesion molecules, reduce excessive sympathetic tone, avoid increased vascular oxidative stress, reverse coagulation abnormalities, and reduce leptin levels. If all this can be achieved by a polysomnogram, then this test should become part of a neurologist's armamentarium for stroke and TIA.

Stroke care in Central Eastern Europe: current problems and call for action.

PubMed

Lenti, Laura; Brainin, Michael; Titianova, Ekaterina; Morovic, Sandra; Demarin, Vida; Kalvach, Pavel; Skoloudik, David; Kobayashi, Adam; Czlonkowska, Anna; Muresanu, Dafin F; Shekhovtsova, Ksenia; Skvortsova, Veronica I; Sternic, Nadezda; Beslac Bumbasirevic, Ljiljana; Svigelj, Viktor; Turcani, Peter; Bereczki, Dániel; Csiba, László

2013-07-01

Stroke is a major medical problem and one of the leading causes of mortality and disability all over in Europe. However, there are significant East-West differences in stroke care as well as in stroke mortality and morbidity rates. Central and Eastern European countries that formerly had centralized and socialist health care systems have serious and similar problems in organizing health and stroke care 20 years after the political transition. In Central and Eastern Europe, stroke is more frequent, the mortality rate is higher, and the victims are younger than in Western Europe. High-risk patients live in worse environmental conditions, and the socioeconomic consequences of stroke further weaken the economic development of these countries. To address these issues, a round table conference was organized. The main aim of this conference was to discuss problems to be solved related to acute and chronic stroke care in Central and Eastern European countries, and also, to exchange ideas on possible solutions. In this article, the discussed problems and possible solutions will be summarized, and introduce 'The Budapest Statement of Stroke Experts of Central and Eastern European countries'. © 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.

Lacunar Infarcts, Depression, and Anxiety Symptoms One Year after Stroke.

PubMed

Arba, Francesco; Ali, Myzoon; Quinn, Terence J; Hankey, Graeme J; Lees, Kennedy R; Inzitari, Domenico

2016-04-01

Mood disorders are frequent after stroke and are associated with poorer quality of life. Previous studies have reported conflicting results as to stroke subtype in the incidence of poststroke mood disorders. We explored the relationship between subcortical ischemic stroke subtype (lacunar) and presence of such symptoms at 1 year after stroke. Anonymized data were accessed from the Virtual International Stroke Trials Archive. Stroke subtypes were classified according to the Trial of Org 10172 in Acute Stroke Treatment classification. Depression and anxiety symptoms were assessed using Hospital Anxiety and Depression Scale. We investigated independent predictors of depression and anxiety symptoms using a logistic regression model. Data were available for 2160 patients. Almost one fifth of the patients developed both anxiety and depression at 1-year follow-up. After adjusting for confounders, the lacunar subtype was least associated with both anxiety (odds ratio [OR] = .61; 95% confidence interval [CI] = .46-.80) and depression symptoms (OR = .71; CI = .55-.93) versus other stroke subtypes. Lacunar strokes have a weaker association with presence of anxiety and depression symptoms compared with other subtypes. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Serum leptin levels and the risk of stroke: The Framingham Study

PubMed Central

Saber, Hamidreza; Himali, Jayandra J.; Shoamanesh, Ashkan; Beiser, Alexa; Pikula, Alexandra; Harris, Tamara B.; Roubenoff, Ronenn; Romero, Jose Rafael; Kase, Carlos S.; Vasan, Ramachandran S.; Seshadri, Sudha

2015-01-01

Background and Purpose Leptin is a major adipokine that regulates weight balance and energy homeostasis. There is inconsistent evidence linking circulating leptin levels to risk of stroke. We tested the hypothesis that leptin levels are associated with risk of incident stroke in an elderly community-based sample. Methods Serum leptin levels were assayed in 757 stroke-free individuals (mean age 79 years, 62% women) from the Framingham Original cohort at the 22nd examination cycle (1990–1994). Incidence of all-stroke and ischemic stroke were prospectively ascertained. Results During a mean follow-up of 10 years, 119 individuals developed stroke (99 ischemic stroke). In multivariable Cox regression models, log-leptin levels were not associated with incidence of all-stroke or ischemic stroke (hazard ratios[HR] per standard deviation(SD) increment in log-leptin 0.9 [0.73–1.09] and 0.89 [0.72–1.11], respectively). The results were suggestive for potential effect modification by waist-hip ratio(WHR) for the association between leptin and stroke (P=0.03). Adjusting for age, sex and established stroke risk factors, analysis stratified by WHR quartiles revealed a lower incidence of first-ever all-stroke and ischemic stroke associated with higher leptin levels among only subjects in the top WHR quartile (HR, 0.64 [0.43, 0.95] versus 0.98 [0.77, 1.25], for incident all-stroke and 0.61 [0.39, 0.95] versus 0.96 [0.74, 1.26] for ischemic stroke). Conclusions Leptin levels were not directly related to risk of incident stroke overall but there was an inverse association with stroke in the top WHR quartile. Further investigations are required to confirm these findings and explore possible mechanisms for the observed association. PMID:26337973

Effect of Visual Art School-Based Stroke Intervention for Middle School Students.

PubMed

Johnson, Ashleigh B; Montgomery, Chelsea M; Dillard, Wesley A; Morrill, Kenneth; Hoesli, Coral; Gillette, Wesley M; Johnson, Brandon K; Nathaniel, Thomas I

2017-08-01

Community stroke awareness initiatives have traditionally been used to expand knowledge of stroke signs and risk factors to high-risk adult populations. Here, we use a novel unfettered, visual art-based approach for an elementary school initiative to raise stroke awareness. Seventh graders in a middle school art class received stroke awareness training during the course of the 2015 to 2016 school year through their teacher in the visual arts class. In turn, they used this training to develop their own artistic interpretations of key stroke awareness concepts via project-based learning and then present their projects to raise awareness about stroke. We evaluated our predata and postdata to determine whether the visual art school-based stroke intervention was effective in both educating students about stroke and enabling them to effectively disseminate this information to parents and other adults in their community. The pretest evaluation indicates a fair or good knowledge about stroke, and no student indicated an "outstanding" or "excellent" knowledge. The posttest evaluation indicated a higher degree of stroke awareness because students were rated as having an "outstanding," "excellent," or "very good" performance especially in the ability to translate knowledge of stroke awareness lessons learned in their art class into a well-articulated stroke-related project and presentation. Pearson χ test reveals significant difference (P < .001) between the pretest and posttest evaluations. Our results indicate that our school-based stroke intervention was effective in both educating students about stroke and enabling them to effectively disseminate this information to parents and other adults in their community. The use of a visual art teacher to lead the educational component in the intervention indicates that expertise in neurology or stroke is not necessary to facilitate understanding of stroke and highlights the importance of creativeness in stroke education for children.

Assessment of motion of a swing leg and gait rehabilitation with a gravity balancing exoskeleton.

PubMed

Agrawal, Sunil K; Banala, Sai K; Fattah, Abbas; Sangwan, Vivek; Krishnamoorthy, Vijaya; Scholz, John P; Hsu, Wei-Li

2007-09-01

The gravity balancing exoskeleton, designed at University of Delaware, Newark, consists of rigid links, joints and springs, which are adjustable to the geometry and inertia of the leg of a human subject wearing it. This passive exoskeleton does not use any motors but is designed to unload the human leg joints from the gravity load over its range-of-motion. The underlying principle of gravity balancing is to make the potential energy of the combined leg-machine system invariant with configuration of the leg. Additionally, parameters of the exoskeleton can be changed to achieve a prescribed level of gravity assistance, from 0% to 100%. The goal of the results reported in this paper is to provide preliminary quantitative assessment of the changes in kinematics and kinetics of the walking gait when a human subject wears such an exoskeleton. The data on kinematics and kinetics were collected on four healthy and three stroke patients who wore this exoskeleton. These data were computed from the joint encoders and interface torque sensors mounted on the exoskeleton. This exoskeleton was also recently used for a six-week training of a chronic stroke patient, where the gravity assistance was progressively reduced from 100% to 0%. The results show a significant improvement in gait of the stroke patient in terms of range-of-motion of the hip and knee, weight bearing on the hemiparetic leg, and speed of walking. Currently, training studies are underway to assess the long-term effects of such a device on gait rehabilitation of hemiparetic stroke patients.

Computational neurorehabilitation: modeling plasticity and learning to predict recovery.

PubMed

Reinkensmeyer, David J; Burdet, Etienne; Casadio, Maura; Krakauer, John W; Kwakkel, Gert; Lang, Catherine E; Swinnen, Stephan P; Ward, Nick S; Schweighofer, Nicolas

2016-04-30

Despite progress in using computational approaches to inform medicine and neuroscience in the last 30 years, there have been few attempts to model the mechanisms underlying sensorimotor rehabilitation. We argue that a fundamental understanding of neurologic recovery, and as a result accurate predictions at the individual level, will be facilitated by developing computational models of the salient neural processes, including plasticity and learning systems of the brain, and integrating them into a context specific to rehabilitation. Here, we therefore discuss Computational Neurorehabilitation, a newly emerging field aimed at modeling plasticity and motor learning to understand and improve movement recovery of individuals with neurologic impairment. We first explain how the emergence of robotics and wearable sensors for rehabilitation is providing data that make development and testing of such models increasingly feasible. We then review key aspects of plasticity and motor learning that such models will incorporate. We proceed by discussing how computational neurorehabilitation models relate to the current benchmark in rehabilitation modeling - regression-based, prognostic modeling. We then critically discuss the first computational neurorehabilitation models, which have primarily focused on modeling rehabilitation of the upper extremity after stroke, and show how even simple models have produced novel ideas for future investigation. Finally, we conclude with key directions for future research, anticipating that soon we will see the emergence of mechanistic models of motor recovery that are informed by clinical imaging results and driven by the actual movement content of rehabilitation therapy as well as wearable sensor-based records of daily activity.

Haptic exploration of fingertip-sized geometric features using a multimodal tactile sensor

NASA Astrophysics Data System (ADS)

Ponce Wong, Ruben D.; Hellman, Randall B.; Santos, Veronica J.

2014-06-01

Haptic perception remains a grand challenge for artificial hands. Dexterous manipulators could be enhanced by "haptic intelligence" that enables identification of objects and their features via touch alone. Haptic perception of local shape would be useful when vision is obstructed or when proprioceptive feedback is inadequate, as observed in this study. In this work, a robot hand outfitted with a deformable, bladder-type, multimodal tactile sensor was used to replay four human-inspired haptic "exploratory procedures" on fingertip-sized geometric features. The geometric features varied by type (bump, pit), curvature (planar, conical, spherical), and footprint dimension (1.25 - 20 mm). Tactile signals generated by active fingertip motions were used to extract key parameters for use as inputs to supervised learning models. A support vector classifier estimated order of curvature while support vector regression models estimated footprint dimension once curvature had been estimated. A distal-proximal stroke (along the long axis of the finger) enabled estimation of order of curvature with an accuracy of 97%. Best-performing, curvature-specific, support vector regression models yielded R2 values of at least 0.95. While a radial-ulnar stroke (along the short axis of the finger) was most helpful for estimating feature type and size for planar features, a rolling motion was most helpful for conical and spherical features. The ability to haptically perceive local shape could be used to advance robot autonomy and provide haptic feedback to human teleoperators of devices ranging from bomb defusal robots to neuroprostheses.

Nursing care for stroke patients: A survey of current practice in 11 European countries.

PubMed

Tulek, Zeliha; Poulsen, Ingrid; Gillis, Katrin; Jönsson, Ann-Cathrin

2018-02-01

To conduct a survey of the clinical nursing practice in European countries in accordance with the European Stroke Strategies 2006 and to examine to what extent the European Stroke Strategies have been implemented in stroke care nursing in Europe. Stroke is a leading cause of death and disability globally. Optimal organisation of interdisciplinary stroke care is expected to ameliorate outcome after stroke. Consequently, universal access to stroke care based on evidence-based guidelines is a priority. This study is a descriptive cross-sectional survey. A questionnaire comprising 61 questions based on the European Stroke Strategies and scientific evidence in nursing practice was distributed to representatives of the European Association of Neuroscience Nurses, who sent the questionnaire to nurses active in stroke care. The questionnaire covered the following areas of stroke care: organisation of stroke services, management of acute stroke and prevention including basic care and nursing, and secondary prevention. Ninety-two nurses in stroke care in 11 European countries participated in the survey. Within the first 48 hr after stroke onset, 95% monitor patients regularly, 94% start mobilisation after 24 hr when patients are stable, and 89% assess patients' ability to swallow. Change of position for immobile patients is followed by 73%, and postvoid residual urine volume is measured by 85%. Some aspects needed improvement, for example, staff education (70%), education for patients/families/carers (55%) and individual care plans in secondary prevention (62%). The participating European countries comply well with the European Stroke Strategies guidelines, particularly in the acute stroke care, but not all stroke units have reached optimal development in all aspects of stroke care nursing. Our study may provide clinical administrators and nurses in stroke care with information that may contribute to improved compliance with the European Stroke Strategies and evidence-based guidelines. © 2017 John Wiley & Sons Ltd.

Advancing stroke genomic research in the age of Trans-Omics big data science: Emerging priorities and opportunities.

PubMed

Owolabi, Mayowa; Peprah, Emmanuel; Xu, Huichun; Akinyemi, Rufus; Tiwari, Hemant K; Irvin, Marguerite R; Wahab, Kolawole Wasiu; Arnett, Donna K; Ovbiagele, Bruce

2017-11-15

We systematically reviewed the genetic variants associated with stroke in genome-wide association studies (GWAS) and examined the emerging priorities and opportunities for rapidly advancing stroke research in the era of Trans-Omics science. Using the PRISMA guideline, we searched PubMed and NHGRI- EBI GWAS catalog for stroke studies from 2007 till May 2017. We included 31 studies. The major challenge is that the few validated variants could not account for the full genetic risk of stroke and have not been translated for clinical use. None of the studies included continental Africans. Genomic study of stroke among Africans presents a unique opportunity for the discovery, validation, functional annotation, Trans-Omics study and translation of genomic determinants of stroke with implications for global populations. This is because all humans originated from Africa, a continent with a unique genomic architecture and a distinctive epidemiology of stroke; as well as substantially higher heritability and resolution of fine mapping of stroke genes. Understanding the genomic determinants of stroke and the corresponding molecular mechanisms will revolutionize the development of a new set of precise biomarkers for stroke prediction, diagnosis and prognostic estimates as well as personalized interventions for reducing the global burden of stroke. Copyright © 2017 Elsevier B.V. All rights reserved.

Pathophysiology, treatment, and animal and cellular models of human ischemic stroke

PubMed Central

2011-01-01

Stroke is the world's second leading cause of mortality, with a high incidence of severe morbidity in surviving victims. There are currently relatively few treatment options available to minimize tissue death following a stroke. As such, there is a pressing need to explore, at a molecular, cellular, tissue, and whole body level, the mechanisms leading to damage and death of CNS tissue following an ischemic brain event. This review explores the etiology and pathogenesis of ischemic stroke, and provides a general model of such. The pathophysiology of cerebral ischemic injury is explained, and experimental animal models of global and focal ischemic stroke, and in vitro cellular stroke models, are described in detail along with experimental strategies to analyze the injuries. In particular, the technical aspects of these stroke models are assessed and critically evaluated, along with detailed descriptions of the current best-practice murine models of ischemic stroke. Finally, we review preclinical studies using different strategies in experimental models, followed by an evaluation of results of recent, and failed attempts of neuroprotection in human clinical trials. We also explore new and emerging approaches for the prevention and treatment of stroke. In this regard, we note that single-target drug therapies for stroke therapy, have thus far universally failed in clinical trials. The need to investigate new targets for stroke treatments, which have pleiotropic therapeutic effects in the brain, is explored as an alternate strategy, and some such possible targets are elaborated. Developing therapeutic treatments for ischemic stroke is an intrinsically difficult endeavour. The heterogeneity of the causes, the anatomical complexity of the brain, and the practicalities of the victim receiving both timely and effective treatment, conspire against developing effective drug therapies. This should in no way be a disincentive to research, but instead, a clarion call to intensify efforts to ameliorate suffering and death from this common health catastrophe. This review aims to summarize both the present experimental and clinical state-of-the art, and to guide future research directions. PMID:21266064

Exploring the experience of facilitating self-management with minority ethnic stroke survivors: a qualitative study of therapists' perceptions

PubMed Central

Jones, Fiona; Kilbride, Cherry; Victor, Christina

2014-01-01

Purpose: The utility of self-management with people from minority ethnic backgrounds has been questioned, resulting in the development of culturally specific tools. Yet, the use of stroke specific self-management programmes is underexplored in these high risk groups. This article presents the experience of stroke therapists in using a stroke specific self-management programme with stroke survivors from minority ethnic backgrounds. Methods: 26 stroke therapists with experience of using the self-management programme with stroke survivors from minority ethnic backgrounds participated in semi-structured interviews. These were audio recorded, transcribed verbatim and analysed thematically. Results: Three themes were identified. One questioned perceived differences in stroke survivors interaction with self-management based on ethnicity. The other themes contrasted with this view demonstrating two areas in which ethnic and cultural attributes were deemed to influence the self-management process both positively and negatively. Aspects of knowledge of health, illness and recovery, religion, family and the professionals themselves are highlighted. Conclusions: This study indicates that ethnicity should not be considered a limitation to the use of an individualized stroke specific self-management programme. However, it highlights potential facilitators and barriers, many of which relate to the capacity of the professional to effectively navigate cultural and ethnic differences. Implications for Rehabilitation Stroke therapists suggest that ethnicity should not be considered a barrier to successful engagement with a stroke specific self-management programme. Health, illness and recovery beliefs along with religion and the specific role of the family do however need to be considered to maximize the effectiveness of the programme. A number of the facilitators and barriers identified are not unique to stroke survivors from ethnic minority communities, nor shared by all. The therapists skills at negotiating identified barriers to self-management are highlighted as an area for further development. PMID:24670190

Hybrid Nanostructured Textile Bioelectrode for Unobtrusive Health Monitoring

NASA Astrophysics Data System (ADS)

Rai, Pratyush

Coronary heart disease, cardiovascular diseases and strokes are the leading causes of mortality in United States of America. Timely point-of-care health diagnostics and therapeutics for person suffering from these diseases can save thousands of lives. However, lack of accessible minimally intrusive health monitoring systems makes timely diagnosis difficult and sometimes impossible. To remedy this problem, a textile based nano-bio-sensor was developed and evaluated in this research. The sensor was made of novel array of vertically standing nanostructures that are conductive nano-fibers projecting from a conductive fabric. These sensor electrodes were tested for the quality of electrical contact that they made with the skin based on the fundamental skin impedance model and electromagnetic theory. The hybrid nanostructured dry electrodes provided large surface area and better contact with skin that improved electrode sensitivity and reduced the effect of changing skin properties, which are the problems usually faced by conventional dry textile electrodes. The dry electrodes can only register strong physiological signals because of high background noise levels, thus limiting the use of existing dry electrodes to heart rate measurement and respiration. Therefore, dry electrode systems cannot be used for recording complete ECG waveform, EEG or measurement of bioimpedance. Because of their improved sensitivity these hybrid nanostructured dry electrodes can be applied to measurement of ECG and bioimpedance with very low baseline noise. These textile based electrodes can be seamlessly integrated into garments of daily use such as vests and bra. In combination with embedded wireless network device that can communicate with smart phone, laptop or GPRS, they can function as wearable wireless health diagnostic systems.

Stroke-Associated Pneumonia Risk Score: Validity in a French Stroke Unit.

PubMed

Cugy, Emmanuelle; Sibon, Igor

2017-01-01

Stroke-associated pneumonia is a leading cause of in-hospital death and post-stroke outcome. Screening patients at high risk is one of the main challenges in acute stroke units. Several screening tests have been developed, but their feasibility and validity still remain unclear. The aim of our study was to evaluate the validity of four risk scores (Pneumonia score, A2DS2, ISAN score, and AIS-APS) in a population of ischemic stroke patients admitted in a French stroke unit. Consecutive ischemic stroke patients admitted to a stroke unit were retrospectively analyzed. Data that allowed to retrospectively calculate the different pneumonia risk scores were recorded. Sensitivity and specificity of each score were assessed for in-hospital stroke-associated pneumonia and mortality. The qualitative and quantitative accuracy and utility of each diagnostic screening test were assessed by measuring the Youden Index and the Clinical Utility Index. Complete data were available for only 1960 patients. Pneumonia was observed in 8.6% of patients. Sensitivity and specificity were, respectively, .583 and .907 for Pneumonia score, .744 and .796 for A2DS2, and .696 and .812 for ISAN score. Data were insufficient to test AIS-APS. Stroke-associated pneumonia risk scores had an excellent negative Clinical Utility Index (.77-.87) to screen for in-hospital risk of pneumonia after acute ischemic stroke. All scores might be useful and applied to screen stroke-associated pneumonia in stroke patients treated in French comprehensive stroke units. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Contribution of Sickle Cell Disease to the Pediatric Stroke Burden Among Hospital Discharges of African-Americans—United States, 1997–2012

PubMed Central

Baker, Charlotte; Grant, Althea M.; George, Mary G.; Grosse, Scott D.; Adamkiewicz, Thomas V.

2015-01-01

Background Approximately 10–20% of children with sickle cell disease (SCD) develop stroke, but few consistent national estimates of the stroke burden for children with SCD exist. The purpose of this study is to determine the proportion of diagnosed stroke among African-American pediatric discharges with and without SCD. Procedure Records for African-Americans aged 1–18 years in the Kids' Inpatient Database (KID) 1997–2012 with ≥1 ICD-9-CM diagnosis code for stroke were included. Data were weighted to provide national estimates. A total of 2,994 stroke cases among African-American children were identified. Diagnoses co-existing with ischemic or hemorrhagic stroke were frequency ranked separately. Results From 1997 through 2012, SCD was present in 24% of stroke discharges, with 89% being ischemic stroke. For hospital discharges of African-American children, SCD is the highest co-existing risk factor for ischemic stroke (29%). Stroke in children with SCD occurred predominantly in children aged 5–9 years, older than previously reported. The trend of stroke discharges significantly decreased for children with SCD from 1997 to 2012 for children aged 10–14 years. Conclusions SCD is a leading risk factor to pediatric stroke in African-American children. Reducing the number of strokes among children with SCD would have a significant impact on the rate of strokes among African-American children. Preventative intervention may be modifying initial age of presentation of stroke in children with SCD. PMID:26174777

Stroke awareness and knowledge in an urban New Zealand population.

PubMed

Bay, Jacquie L; Spiroski, Ana-Mishel; Fogg-Rogers, Laura; McCann, Clare M; Faull, Richard L M; Barber, Peter A

2015-06-01

Stroke is the third most common cause of death and a major cause of chronic disability in New Zealand. Linked to risk factors that develop across the life-course, stroke is considered to be largely preventable. This study assessed the awareness of stroke risk, symptoms, detection, and prevention behaviors in an urban New Zealand population. Demographics, stroke risk factors awareness, symptoms, responsiveness, and prevention behaviors were evaluated using a structured oral questionnaire. Binomial logistic regression analyses were used to identify predictors of stroke literacy. Although personal experience of stroke increased awareness of symptoms and their likeliness to indicate the need for urgent medical attention, only 42.7% of the respondents (n = 850) identified stroke as involving both blood and the brain. Educational attainment at or above a trade certificate, apprenticeship, or diploma increased the awareness of stroke symptoms compared with those with no formal educational attainment. Pacific Island respondents were less likely than New Zealand Europeans to identify a number of stroke risk factors. Māori, Pacific Island, and Asian respondents were less likely to identify symptoms of stroke and indicate the need for urgent medical attention. The variability in stroke awareness and knowledge may suggest the need to enhance stroke-related health literacy that facilitates understanding of risk and of factors that reduce morbidity and mortality after stroke in people of Māori and Pacific Island descent and in those with lower educational attainment or socioeconomic status. It is therefore important that stroke awareness campaigns include tailored components for target audiences. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Ischemic Stroke: From Next Generation Sequencing and GWAS to Community Genomics?

PubMed

Black, Michael; Wang, Wenzhi; Wang, Wei

2015-08-01

Stroke is a major cause of mortality and morbidity in both the developed and developing world. Next generation sequencing (NGS) and multi-omics integrative biology research offer new opportunities in the way we research and understand stroke. These biotechnologies also signal a shift from genetics to genomics of stroke, which is highlighted in this review. Stroke is a focal neurological deficit resulting from disruption of the cerebral blood supply. There are two main types of common stroke, ischemic stroke (IS), which comprises 80% of cases, and hemorrhagic stroke (HS) that accounts for about 20% of cases. IS is a complex multi-factorial disease with multiple environmental and genomic determinants. We discuss here IS from genomics and bioinformatics perspectives, including the highlights of the genome wide association studies (GWAS), NGS progress to date, and exome studies. While both 'common variant, common disease' and 'rare variant, common disease' approaches need to be assessed in tandem, future studies into IS omics should also consider pedigree and/or community based sampling to take account of the complex diversity of IS genetics. We conclude by presenting an example of such community genomics research from China in an extended pedigree sample, and the ways in which the intersection of genomics and global society can usefully inform our understanding of IS pathophysiology and potential preventive medicine interventions in the future.

Does non-central nervous system tuberculosis increase the risk of ischemic stroke? A population-based propensity score-matched follow-up study.

PubMed

Wu, Chueh-Hung; Chen, Li-Sheng; Yen, Ming-Fang; Chiu, Yueh-Hsia; Fann, Ching-Yuan; Chen, Hsiu-Hsi; Pan, Shin-Liang

2014-01-01

Previous studies on the association between tuberculosis and the risk of developing ischemic stroke have generated inconsistent results. We therefore performed a population-based, propensity score-matched longitudinal follow-up study to investigate whether contracting non-central nervous system (CNS) tuberculosis leads to an increased risk of ischemic stroke. We used a logistic regression model that includes age, sex, pre-existing comorbidities and socioeconomic status as covariates to compute the propensity score. A total of 5804 persons with at least three ambulatory visits in 2001 with the principal diagnosis of non-CNS tuberculosis were enrolled in the tuberculosis group. The non-tuberculosis group consisted of 5804, propensity score-matched subjects without tuberculosis. The three-year ischemic stroke-free survival rates for these 2 groups were estimated using the Kaplan-Meier method. The stratified Cox proportional hazards regression was used to estimate the effect of tuberculosis on the occurrence of ischemic stroke. During three-year follow-up, 176 subjects in the tuberculosis group (3.0%) and 207 in the non-tuberculosis group (3.6%) had ischemic stroke. The hazard ratio for developing ischemic stroke in the tuberculosis group was 0.92 compared to the non-tuberculosis group (95% confidence interval: 0.73-1.14, P = 0.4299). Non-CNS tuberculosis does not increase the risk of subsequent ischemic stroke.

A measure of early physical functioning (EPF) post-stroke.

PubMed

Finch, Lois E; Higgins, Johanne; Wood-Dauphinee, Sharon; Mayo, Nancy E

2008-07-01

To develop a comprehensive measure of Early Physical Functioning (EPF) post-stroke quantified through Rasch analysis and conceptualized using the International Classification of Functioning Disability and Health (ICF). An observational cohort study. A cohort of 262 subjects (mean age 71.6 (standard deviation 12.5) years) hospitalized post-acute stroke. Functional assessments were made within 3 days of stroke with items from valid and reliable indices commonly utilized to evaluate stroke survivors. Information on important variables was also collected. Principal component and Rasch analysis confirmed the factor structure, and dimensionality of the measure. Rasch analysis combined items across ICF components to develop the measure. Items were deleted iteratively, those retained fit the model and were related to the construct; reliability and validity were assessed. A 38-item unidimensional measure of the EPF met all Rasch model requirements. The item difficulty matched the person ability (mean person measure: -0.31; standard error 0.37 logits), reliability of the person-item-hierarchy was excellent at 0.97. Initial validity was adequate. The 38-item EPF measure was developed. It expands the range of assessment post acute stroke; it covers a broad spectrum of difficulty with good initial psychometric properties that, once revalidated, can assist in planning and evaluating early interventions.

Risk and mortality of traumatic brain injury in stroke patients: two nationwide cohort studies.

PubMed

Chou, Yi-Chun; Yeh, Chun-Chieh; Hu, Chaur-Jong; Meng, Nai-Hsin; Chiu, Wen-Ta; Chou, Wan-Hsin; Chen, Ta-Liang; Liao, Chien-Chang

2014-01-01

Patients with stroke had higher incidence of falls and hip fractures. However, the risk of traumatic brain injury (TBI) and post-TBI mortality in patients with stroke was not well defined. Our study is to investigate the risk of TBI and post-TBI mortality in patients with stroke. Using reimbursement claims from Taiwan's National Health Insurance Research Database, we conducted a retrospective cohort study of 7622 patients with stroke and 30 488 participants without stroke aged 20 years and older as reference group. Data were collected on newly developed TBI after stroke with 5 to 8 years' follow-up during 2000 to 2008. Another nested cohort study including 7034 hospitalized patients with TBI was also conducted to analyze the contribution of stroke to post-TBI in-hospital mortality. Compared with the nonstroke cohort, the adjusted hazard ratio of TBI risk among patients with stroke was 2.80 (95% confidence interval = 2.58-3.04) during the follow-up period. Patients with stroke had higher mortality after TBI than those without stroke (10.2% vs 3.2%, P < .0001) with an adjusted relative risk (RR) of 1.46 (95% confidence interval = 1.15-1.84). Recurrent stroke (RR = 1.60), hemorrhagic stroke (RR = 1.68), high medical expenditure for stroke (RR = 1.80), epilepsy (RR = 1.79), neurosurgery (RR = 1.94), and hip fracture (RR = 2.11) were all associated with significantly higher post-TBI mortality among patients with stroke. Patients with stroke have an increased risk of TBI and in-hospital mortality after TBI. Various characteristics of stroke severity were all associated with higher post-TBI mortality. Special attention is needed to prevent TBI among these populations.

Higher total serum cholesterol levels are associated with less severe strokes and lower all-cause mortality: ten-year follow-up of ischemic strokes in the Copenhagen Stroke Study.

PubMed

Olsen, Tom Skyhøj; Christensen, Rune Haubo Bojesen; Kammersgaard, Lars Peter; Andersen, Klaus Kaae

2007-10-01

Evidence of a causal relation between serum cholesterol and stroke is inconsistent. We investigated the relation between total serum cholesterol and both stroke severity and poststroke mortality to test the hypothesis that hypercholesterolemia is primarily associated with minor stroke. In the study, 652 unselected patients with ischemic stroke arrived at the hospital within 24 hours of stroke onset. A measure of total serum cholesterol was obtained in 513 (79%) within the 24-hour time window. Stroke severity was measured with the Scandinavian Stroke Scale (0=worst, 58=best); a full cardiovascular risk profile was established for all. Death within 10 years after stroke onset was obtained from the Danish Registry of Persons. Mean+/-SD age of the 513 patients was 75+/-10 years, 54% were women, and the mean+/-SD Scandinavian Stroke Scale score was 39+/-17. Serum cholesterol was inversely and almost linearly related to stroke severity: an increase of 1 mmol/L in total serum cholesterol resulted in an increase in the Scandinavian Stroke Scale score of 1.32 (95% CI, 0.28 to 2.36, P=0.013), meaning that higher cholesterol levels are associated with less severe strokes. A survival analysis revealed an inverse linear relation between serum cholesterol and mortality, meaning that an increase of 1 mmol/L in cholesterol results in a hazard ratio of 0.89 (95% CI, 0.82 to 0.97, P=0.01). The results of our study support the hypothesis that a higher cholesterol level favors development of minor strokes. Because of selection, therefore, major strokes are more often seen in patients with lower cholesterol levels. Poststroke mortality, therefore, is inversely related to cholesterol.

Optimizing stroke clinical trial design: estimating the proportion of eligible patients.

PubMed

Taylor, Alexis; Castle, Amanda; Merino, José G; Hsia, Amie; Kidwell, Chelsea S; Warach, Steven

2010-10-01

Clinical trial planning and site selection require an accurate estimate of the number of eligible patients at each site. In this study, we developed a tool to calculate the proportion of patients who would meet a specific trial's age, baseline severity, and time to treatment inclusion criteria. From a sample of 1322 consecutive patients with acute ischemic cerebrovascular syndromes, we developed regression curves relating the proportion of patients within each range of the 3 variables. We used half the patients to develop the model and the other half to validate it by comparing predicted vs actual proportions who met the criteria for 4 current stroke trials. The predicted proportion of patients meeting inclusion criteria ranged from 6% to 28% among the different trials. The proportion of trial-eligible patients predicted from the first half of the data were within 0.4% to 1.4% of the actual proportion of eligible patients. This proportion increased logarithmically with National Institutes of Health Stroke Scale score and time from onset; lowering the baseline limits of the National Institutes of Health Stroke Scale score and extending the treatment window would have the greatest impact on the proportion of patients eligible for a stroke trial. This model helps estimate the proportion of stroke patients eligible for a study based on different upper and lower limits for age, stroke severity, and time to treatment, and it may be a useful tool in clinical trial planning.

The Influence of Acute Hyperglycemia in an Animal Model of Lacunar Stroke That Is Induced by Artificial Particle Embolization

PubMed Central

Tsai, Ming-Jun; Lin, Ming-Wei; Huang, Yaw-Bin; Kuo, Yu-Min; Tsai, Yi-Hung

2016-01-01

Animal and clinical studies have revealed that hyperglycemia during ischemic stroke increases the stroke's severity and the infarct size in clinical and animal studies. However, no conclusive evidence demonstrates that acute hyperglycemia worsens post-stroke outcomes and increases infarct size in lacunar stroke. In this study, we developed a rat model of lacunar stroke that was induced via the injection of artificial embolic particles during full consciousness. We then used this model to compare the acute influence of hyperglycemia in lacunar stroke and diffuse infarction, by evaluating neurologic behavior and the rate, size, and location of the infarction. The time course of the neurologic deficits was clearly recorded from immediately after induction to 24 h post-stroke in both types of stroke. We found that acute hyperglycemia aggravated the neurologic deficit in diffuse infarction at 24 h after stroke, and also aggravated the cerebral infarct. Furthermore, the infarct volumes of the basal ganglion, thalamus, hippocampus, and cerebellum but not the cortex were positively correlated with serum glucose levels. In contrast, acute hyperglycemia reduced the infarct volume and neurologic symptoms in lacunar stroke within 4 min after stroke induction, and this effect persisted for up to 24 h post-stroke. In conclusion, acute hyperglycemia aggravated the neurologic outcomes in diffuse infarction, although it significantly reduced the size of the cerebral infarct and improved the neurologic deficits in lacunar stroke. PMID:27226775

Progress in reducing the burden of stroke.

PubMed

Chalmers, J; Chapman, N

2001-12-01

1. The burden of stroke worldwide is growing rapidly, driven by an ageing population and by the rapid rate of urbanization and industrialization in the developing world. There are approximately 5 million fatal and 15 million non-fatal strokes each year and over 50 million survivors of stroke alive, worldwide, today. 2. The most important determinant of stroke risk is blood pressure, with a strong, continuous relationship between the level of the systolic and diastolic pressures and the risk of initial and recurrent stroke, in both Western and Asian populations. 3. Randomized clinical trials have clearly demonstrated that blood pressure lowering reduces the risk of initial stroke by 35-40% in hypertensive patients; but, until recently, there was no conclusive evidence that blood pressure lowering was effective in the secondary prevention of stroke. 4. The Perindopril Protection Against Recurrent Stroke Study (PROGRESS) has provided definitive evidence that blood pressure lowering in patients with previous stroke or transient ischaemic attack (TIA) reduces the incidence of secondary stroke by 28%, of major vascular events by 26% and of major coronary events by 26%. These reductions were all magnified by approximately 50% in a subgroup of patients in whom the angiotensin-converting enzyme inhibitor perindopril was routinely combined with the diuretic indapamide. 5. Successful global implementation of a treatment with perindopril and indapamide in patients with a history of stroke or TIA would markedly reduce the burden of stroke and could avert between 0.5 and one million strokes each year, worldwide.

[IL-1beta, IL-10, INF-gamma, TNF-alpha, S100beta, AMA-M2 and cell immune response in stroke].

PubMed

Sergeeva, S P; Erofeeva, L M; Gul'tiaev, M M

2011-01-01

Clinical data showed a role for stress, inflammatory, innate immune and adaptive immune mechanisms is stroke. Absolute and relative count of lymphocytes decrease, CD3 HLA DR+ and immunoregulatory balance (CD4+/CD8+) increase, concentration of IL-1beta, INF-gamma, TNF-alpha, S100beta, AMA-M2 increase, IL-10 decrease were detected in peripheral blood of 25 patients with stroke. It is explained that the products of brain cell stroke destruction (AMA-M2) play in autoimmune stroke progress mechanisms the same role as neurospecific proteins as S100beta. It is concluded that both stereotype and autoimmune mechanisms are involved in the development of stroke.

Developing a Cantonese Version of Birmingham Cognitive Screen for Stroke Survivors in Hong Kong

ERIC Educational Resources Information Center

Kong, Anthony Pak-Hin; Chan, John; Lau, Johnny King-L.; Bickerton, Wai-Ling; Weekes, Brendan; Humphreys, Glyn

2018-01-01

The "Birmingham Cognitive Screen" (BCoS) is a neuropsychological battery designed to assess impairment to a variety of cognitive domains including language in patients with brain injuries. Twenty-two stroke participants and 16 gender-, age-, and education-matched controls were recruited in Hong Kong. The stroke participants were…

The H2 robotic exoskeleton for gait rehabilitation after stroke: early findings from a clinical study.

PubMed

Bortole, Magdo; Venkatakrishnan, Anusha; Zhu, Fangshi; Moreno, Juan C; Francisco, Gerard E; Pons, Jose L; Contreras-Vidal, Jose L

2015-06-17

Stroke significantly affects thousands of individuals annually, leading to considerable physical impairment and functional disability. Gait is one of the most important activities of daily living affected in stroke survivors. Recent technological developments in powered robotics exoskeletons can create powerful adjunctive tools for rehabilitation and potentially accelerate functional recovery. Here, we present the development and evaluation of a novel lower limb robotic exoskeleton, namely H2 (Technaid S.L., Spain), for gait rehabilitation in stroke survivors. H2 has six actuated joints and is designed to allow intensive overground gait training. An assistive gait control algorithm was developed to create a force field along a desired trajectory, only applying torque when patients deviate from the prescribed movement pattern. The device was evaluated in 3 hemiparetic stroke patients across 4 weeks of training per individual (approximately 12 sessions). The study was approved by the Institutional Review Board at the University of Houston. The main objective of this initial pre-clinical study was to evaluate the safety and usability of the exoskeleton. A Likert scale was used to measure patient's perception about the easy of use of the device. Three stroke patients completed the study. The training was well tolerated and no adverse events occurred. Early findings demonstrate that H2 appears to be safe and easy to use in the participants of this study. The overground training environment employed as a means to enhance active patient engagement proved to be challenging and exciting for patients. These results are promising and encourage future rehabilitation training with a larger cohort of patients. The developed exoskeleton enables longitudinal overground training of walking in hemiparetic patients after stroke. The system is robust and safe when applied to assist a stroke patient performing an overground walking task. Such device opens the opportunity to study means to optimize a rehabilitation treatment that can be customized for individuals. This study was registered at ClinicalTrials.gov ( https://clinicaltrials.gov/show/NCT02114450 ).

Pre-Stroke Use of Beta-Blockers Does Not Lower Post-Stroke Infection Rate: An Exploratory Analysis of the Preventive Antibiotics in Stroke Study.

PubMed

Westendorp, Willeke F; Vermeij, Jan-Dirk; Brouwer, Matthijs C; Roos, Y B W E M; Nederkoorn, Paul J; van de Beek, Diederik

2016-01-01

Stroke-associated infections occur frequently and are associated with unfavorable outcome. Previous cohort studies suggest a protective effect of beta-blockers (BBs) against infections. A sympathetic drive may increase immune suppression and infections. This study is aimed at investigating the association between BB treatment at baseline and post-stroke infection in the Preventive Antibiotics in Stroke Study (PASS), a prospective clinical trial. We performed an exploratory analysis in PASS, 2,538 patients with acute phase of stroke (24 h after onset) were randomized to ceftriaxone (intravenous, 2 g per day for 4 days) in addition to stroke unit care, or standard stroke unit care without preventive antibiotic treatment. All clinical data, including use of BBs, was prospectively collected. Infection was diagnosed by the treating physician, and independently by an expert panel blinded for all other data. Multivariable analysis was performed to investigate the relation between BB treatment and infection rate. Infection, as defined by the physician, occurred in 348 of 2,538 patients (14%). Multivariable analysis showed that the use of BBs at baseline was associated with the development of infection during clinical course (adjusted OR (aOR) 1.61, 95% CI 1.19-2.18; p < 0.01). BB use at baseline was also associated with the development of pneumonia (aOR 1.56, 95% CI 1.05-2.30; p = 0.03). Baseline BB use was not associated with mortality (aOR 1.14, 95% CI 0.84-1.53; p = 0.41) or unfavorable outcome at 3 months (aOR 1.10, 95% CI 0.89-1.35; p = 0.39). Patients treated with BBs prior to stroke have a higher rate of infection and pneumonia. © 2016 S. Karger AG, Basel.

Serum hsCRP: A Novel Marker for Prediction of Cerebrovascular Accidents (Stroke).

PubMed

Patgiri, Dibyaratna; Pathak, Mauchumi Saikia; Sharma, Pradeep; Kutum, Tridip; Mattack, Nirmali

2014-12-01

Strokes are caused by disruption of the blood supply to the brain. This may result from either blockage or rupture of a blood vessel. Yearly 15 million people worldwide suffer a stroke. India ranks second worldwide in terms of deaths from stroke. The incidence of stroke increases with age affecting the economically productive middle aged population. Hypertension and male sex are other risk factors for stroke. C-Reactive Protein (CRP) is an acute phase protein whose concentration rises in blood following inflammation. Formerly, assays for CRP detected its rise only after significant inflammation. However, recently developed high sensitivity assays (hsCRP) enable the measurement of CRP in individuals who are apparently healthy. Several studies indicate that hsCRP is elevated in individuals who are at risk of developing Coronary Artery Disease or Cerebrovascular events, the elevation may be found years before the first detection of vascular problems. In the absence of other biochemical markers, the present study aimed to evaluate the predictive and diagnostic role of hsCRP in stroke. The study consisted of 50 patients of acute stroke admitted in Gauhati Medical College and Hospital. The control population consisted of two groups - 50 age and sex matched controls with hypertension (Hypertensive control group) and 50 age and sex matched controls with no obvious disease constituted the Normal control group. hsCRP levels were measured in all the groups and compared statistically. hsCRP is an acute phase reactant whose concentration rises in stroke as well as in those at risk. The rise may be identified even before the appearance of risk factors. Hence, hsCRP may be useful as a predictive and diagnostic marker in stroke.

An individualized coaching program for patients with acute ischemic stroke: Feasibility study.

PubMed

Vanacker, P; Standaert, D; Libbrecht, N; Vansteenkiste, I; Bernard, D; Yperzeele, L; Vanhooren, G

2017-03-01

An individualized stroke care program was developed to match patients' education with their needs regarding stroke knowledge, secondary prevention and rehabilitation. Our purpose was to assess feasibility of in-hospital and post-discharge, personalized stroke coaching service. Acute ischemic stroke patients enrolled in ASTRAL-B stroke registry (Sint-Lucashospital, Bruges Belgium) with: (a) hospitalization between 12/2014-12/2015, (b) hospital-to-home discharge, and (c) without cognitive decline, were selected. The stroke coach contacted patients individually twice during hospitalization (2×20min) and post-discharge via phone calls using the standardized WSO Post-Strokechecklist. Risk factor management, review of therapy and clinical evolution were discussed. Participants were contacted at 2 weeks, followed by repeat calls if necessary and ambulatory with the vascular neurologist at 1, 3, 6 and 12 months. Of all 255 patients meeting the inclusion criteria, 152 (59.7%) received individualized education during hospitalization by the stroke coach. Median age of our population was 74 years and median NIHSS 5. Majority of patients had at least two cardiovascular risk factors. Patients were not coached because of palliative care/decease (10%), unfavorable life expectancy (2%), dementia (8.5%) and lack of time due to short hospitalization (22%). A quarter of all patients were contacted at least once by phone, 12% were contacted at least twice after discharge. At three months, low stroke recurrence (5%) and mortality rates (4%) were identified, probably linked to improved adherence. We demonstrated feasibility of an individualized coaching service executed by well-trained stroke nurse. Future research will focus on developing an online portal delivering post-discharge services to patients and caregivers. Copyright © 2017 Elsevier B.V. All rights reserved.

Robotic devices and brain-machine interfaces for hand rehabilitation post-stroke.

PubMed

McConnell, Alistair C; Moioli, Renan C; Brasil, Fabricio L; Vallejo, Marta; Corne, David W; Vargas, Patricia A; Stokes, Adam A

2017-06-28

To review the state of the art of robotic-aided hand physiotherapy for post-stroke rehabilitation, including the use of brain-machine interfaces. Each patient has a unique clinical history and, in response to personalized treatment needs, research into individualized and at-home treatment options has expanded rapidly in recent years. This has resulted in the development of many devices and design strategies for use in stroke rehabilitation. The development progression of robotic-aided hand physiotherapy devices and brain-machine interface systems is outlined, focussing on those with mechanisms and control strategies designed to improve recovery outcomes of the hand post-stroke. A total of 110 commercial and non-commercial hand and wrist devices, spanning the 2 major core designs: end-effector and exoskeleton are reviewed. The growing body of evidence on the efficacy and relevance of incorporating brain-machine interfaces in stroke rehabilitation is summarized. The challenges involved in integrating robotic rehabilitation into the healthcare system are discussed. This review provides novel insights into the use of robotics in physiotherapy practice, and may help system designers to develop new devices.

Audit report and systematic review of orolingual angioedema in post-acute stroke thrombolysis.

PubMed

Lekoubou, Alain; Philippeau, Frédéric; Derex, Laurent; Olaru, Angel; Gouttard, Michel; Vieillart, Anne; Kengne, Andre Pascal

2014-07-01

Post-intravenous recombinant tissue plasminogen activator (r-tPA) orolingual angioedema (PIROLA), including the life-threatening form, is an underappreciated complication of ischaemic stroke treatment. We present an audit report and a systematic review of published observational studies on PIROLA occurrence in acute ischaemic stroke patients. Clinical files of patients treated in the stroke unit of Bourg-en-Bresse General Hospital (France) from January 2010 to December 2012 were reviewed, and MEDLINE (inception to May 2013) were searched and bibliographies/citations of retrieved articles examined for evidence of PIROLA. Of the 129 acute ischaemic stroke patients treated at Bourg-en-Bresse between 2010 and 2012, four patients, all receiving angiotensin converting enzyme inhibitor (ACEI), developed a PIROLA (cumulative incidence rate: 32‰). The complication started within an hour of receiving r-tPA and integrally resolved within 3-24 hours, with antihistamines/steroid treatment in two patients. The systematic review identified 27 studies, totalising with ours, over 9050 acute ischaemic stroke patients from 12 countries, among whom 100 (cumulative incidence rate: 17‰; 95% confidence intervals: 8-26), developed a PIROLA within 6-240 minutes of receiving r-tPA, 0-100% of them occurring among patients on ACEI. The complication was contralateral to the stroke location in 47% cases, ipsilateral in 14%, and bilateral in 39%; and resolved within 24 hours with treatment in 90%. No related death was recorded. About 17‰ acute ischaemic stroke patients receiving r-tPA develop PIROLA, occurring essentially among those on concomitant ACEI. PIROLA occurrence should be actively monitored, particularly within the first few hours as some may require urgent lifesaving procedures.

Secular trends in the incidence of and risk factors for ischemic stroke and its subtypes in Japanese population.

PubMed

Kubo, Michiaki; Hata, Jun; Doi, Yasufumi; Tanizaki, Yumihiro; Iida, Mitsuo; Kiyohara, Yutaka

2008-12-16

The study of long-term trends in the incidence of and risk factors for ischemic stroke subtypes could offer insights into primary and secondary prevention. We established 3 cohorts of residents >/=40 years of age in 1961, 1974, and 1988 in the Japanese community of Hisayama. Morphological examinations by autopsy or brain imaging were performed on most of the ischemic stroke cases developed in these cohorts. When 13-year follow-up data were compared, the age-adjusted incidence of ischemic stroke and lacunar infarction declined significantly from the first to the third cohort for both sexes, whereas the incidences of atherothrombotic and cardioembolic infarction did not change during this period. Hypertension was a powerful risk factor for the development of ischemic stroke, and improvement of hypertension control would have largely influenced this declining trend: The age- and sex-adjusted hazard ratio of hypertension decreased from 3.25 (95% CI 2.17 to 4.86) in the first cohort to 1.83 (1.29 to 2.58) in the third cohort. A rapid increase in the prevalence of metabolic disorders may have offset the impact of improvements in hypertension control and resulted in a slowdown of the decline in the incidence of ischemic stroke in the cohorts in the present study; however, hypertension still makes a large contribution to the development of ischemic stroke. These findings suggest that in the Japanese population, the incidence of ischemic stroke has declined significantly over the past 40 years, probably owing to better management of hypertension. There is a need for greater primary prevention efforts in the treatment of hypertension and metabolic disorders.

Oxfordshire community stroke project clinical stroke syndrome and appearances of tissue and vascular lesions on pretreatment ct in hyperacute ischemic stroke among the first 510 patients in the Third International Stroke Trial (IST-3).

PubMed

Kobayashi, Adam; Wardlaw, Joanna M; Lindley, Richard I; Lewis, Steff C; Sandercock, Peter A G; Czlonkowska, Anna

2009-03-01

The Oxfordshire Community Stroke Project (OCSP) clinical stroke syndrome classification correlates well with the stroke lesion in established ischemic stroke, but there are few data in patients with hyperacute stroke. We wished to assess whether the OCSP correlated with the site and size of the ischemic lesion and location of cerebral vessel lesion on computed tomography (CT) in hyperacute stroke. Prospective study of ischemic stroke patients presenting within 6 hours of onset in the Third International Stroke Trial (IST-3), a randomized, controlled trial of rt-PA. OCSP syndrome was assigned by a computer-based algorithm. The CT assessment was made by a neuroradiologist blinded to clinical details. We assessed baseline data and CT findings for the first 510 patients; early tissue ischemic changes were present in 329/510 (65%) total anterior circulation syndrome (TACS) - 79%; partial anterior circulation syndrome (PACS) - 57%, lacunar syndrome (LACS) - 40%; posterior circulation syndrome (POCS) - 33%. The site and size of ischemic change on CT was compatible with the clinical syndrome in 79%, 37%, 2%, and 14%, respectively. Assuming that all patients with a normal CT scan will develop an incompatible lesion these numbers reflected the "worst possible scenario." For the "best possible scenario" we presumed that those with a normal CT will develop concordant ischemic change and the proportions were 100%, 80%, 62% and 81%, respectively. The hyperattenuated artery sign was seen in 206/510 (40%); (TACS 54%; PACS 35%, LACS 5%, and POCS 19%). Within 6 hours of stroke, in patients with a nonlacunar syndrome, the OCSP syndrome correlated well with the pattern of ischemic change on CT. For clinicians who wish to restrict the use of thrombolytic therapy to large-artery ischemic stroke, concordance of clinical and CT appearances may give greater confidence in making therapeutic decisions in hyperacute stroke. In centers where immediate access to MR is limited, use of the classification may help focus use of MR on patients with suspected LACS and POCS. The utility of the classification may further increase if IST-3 establishes that the OCSP syndrome significantly modifies response to thrombolytic therapy.

Canadian Association of Emergency Physicians position statement on acute ischemic stroke.

PubMed

Harris, Devin; Hall, Christopher; Lobay, Kevin; McRae, Andrew; Monroe, Tanya; Perry, Jeffrey J; Shearing, Anthony; Wollam, Gabe; Goddard, Tom; Lang, Eddy

2015-03-01

The CAEP Stroke Practice Committee was convened in the spring of 2013 to revisit the 2001 policy statement on the use of thrombolytic therapy in acute ischemic stroke. The terms of reference of the panel were developed to include national representation from urban academic centres as well as community and rural centres from all regions of the country. Membership was determined by attracting recognized stroke leaders from across the country who agreed to volunteer their time towards the development of revised guidance on the topic. The guideline panel elected to adopt the GRADE language to communicate guidance after review of existing systematic reviews and international clinical practice guidelines. Stroke neurologists from across Canada were engaged to work alongside panel members to develop guidance as a dyad-based consensus when possible. There was no unique systematic review performed to support this guidance, rather existing efficacy data was relied upon. After a series of teleconferences and face to face meetings, a draft guideline was developed and presented to the CAEP board in June of 2014. The panel noted the development of significant new evidence to inform a number of clinical questions related to acute stroke management. In general terms the recommendations issued by the CAEP Stroke Practice Committee are supportive of the use of thrombolytic therapy when treatment can be administered within 3 hours of symptom onset. The committee is also supportive of system-level changes including pre-hospital interventions, the transport of patients to dedicated stroke centers when possible and tele-health measures to support thrombolytic therapy in a timely window. Of note, after careful deliberation, the panel elected to issue a conditional recommendation against the use of thrombolytic therapy in the 3–4.5 hour window. The view of the committee was that as a result of a narrow risk benefit balance, one that is considerably narrower than the same considerations under 3 hours, a significant number of informed patients and families would opt against the risk of early intracranial hemorrhage and the possibility of increased 90-day mortality that is not seen for more timely treatment. Furthermore, the frequently impaired nature of patients suffering an acute stroke and the difficulties in asking families to make life and death decisions in a highly time-sensitive context led the panel to restrict a strong endorsement of thrombolytic to the 3 hour outermost limit. The committee noted as well that Health Canada has not approved a thrombolytic agent beyond a three hour window in acute ischemic stroke.

Royal College of Physicians Intercollegiate Stroke Working Party evidence-based guidelines for the secondary prevention of stroke through nutritional or dietary modification.

PubMed

Hookway, C; Gomes, F; Weekes, C E

2015-04-01

Each year, 15 million people worldwide and 110,000 people in England have a stroke. Having a stroke increases the risk of having another. There are a number of additional known risk factors that can be modified by diet. The present study aimed to systematically review key nutrients and diets and their role in secondary prevention, as well as provide evidence-based guidelines for use in clinical practice. The work was conducted as part of the process to develop the 4th edition of the Royal College of Physicians' (RCP) National Clinical Guideline (NCG) for Stroke. Questions were generated by the research team, in consultation with the Virtual Stroke Group, an online professional interest group, and the RCP Intercollegiate Stroke Working Party Guideline Development Group. Nine questions covering several individual nutrients and diet combinations were defined and searches conducted up until 31 October 2011 using five electronic databases (Embase, Medline, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Library and Web of Science). All included studies were assessed for quality and risk of bias using van Tulder criteria for randomised controlled trials (RCTs) and Quality of Reporting of Meta-analyses (QUORUM) criteria for systematic reviews. Of 4287 abstracts were identified, 79 papers were reviewed and 29 systematic reviews and RCTs were included to provide evidence for the secondary prevention components of the guidelines. For each question, evidence statements, recommendations and practical considerations were developed. This systematic review process has resulted in the development of evidence-based guidelines for use in clinical practice and has identified areas for further research. © 2014 The British Dietetic Association Ltd.

Role of hypothalamic cannabinoid receptors in post-stroke depression in rats.

PubMed

Wang, Shanshan; Sun, Hong; Liu, Sainan; Wang, Ting; Guan, Jinqun; Jia, Jianjun

2016-03-01

One of the most common psychological consequences of stroke is post-stroke depression (PSD). While more than 30 percent of stroke patients eventually develop PSD, the neurobiological mechanisms underlying such a phenomenon have not been well investigated. Given the critical involvement of hypothalamic-pituitary-adrenal axis and endocannabinoid system in response to stressful stimuli, we evaluated the hypothesis that cannabinoid receptors in the hypothalamus are critical for modulation of post-stroke depression-like behaviors in rats. To this end, rats were treated with middle cerebral artery occlusion (MCAO) followed by chronic unpredictable mild stress (CUMS) treatment procedure. We then assessed the expression of CB1 and CB2 receptors in the hypothalamus, and evaluated the effects of pharmacological stimulations of CB1 or CB2 receptors on the expression and development of depression-like behaviors in PSD rats. We found that PSD rats exhibited decreased the expression of CB1 receptor, but not CB2 receptor, in the ventral medial hypothalamus (VMH). Such an effect was not observed in the dorsally adjacent brain regions. Furthermore, intra-VMH injections of CB2 receptor agonist, but not CB1 receptor agonist, attenuated the expression of depression-like behaviors in PSD rats. Finally, repeated intraperitoneal injections of CB1 or CB2 receptor agonists during CUMS treatment inhibited the development of depression-like behaviors in PSD rats. Taken together, these results suggest that decreased CB1 receptor expression is likely associated with the development of post-stroke depression, and CB2 receptor may be a potential therapeutic target for the treatment post-stroke depressive disorders. Copyright © 2016 Elsevier Inc. All rights reserved.

Symptomatic pulmonary embolism among stroke patients in Taiwan: a retrospective cohort study.

PubMed

Chen, Chih-Chi; Lee, Tsong-Hai; Chung, Chia-Ying; Chang, Wei-Han; Hong, Jia-Pei; Huang, Li-Ting; Tang, Simon F T; Chen, Chih-Kuang

2012-01-01

Stroke patients are at particular risk for developing pulmonary embolism (PE), which is a cardiovascular emergency associated with a high mortality rate. Little information is available on symptomatic PE in Asian stroke patients. To determine the frequency of symptomatic PE in ischemic and hemorrhagic stroke patients; to identify common characteristics and risk factors of symptomatic PE in Taiwanese stroke patients; and to compare the difference between fatal PE and nonfatal PE among these stroke patients. This is a retrospective cohort study of stroke patients admitted between January 2002 and December 2009 to a tertiary referral center in Northern Taiwan. We used the International Classification of Diseases, Ninth Revision, Clinical Modification codes to identify eligible patients. We determined annual frequency and risk factors of symptomatic PE. We also compared the difference between ischemic stroke patients with fatal and nonfatal PE. Among the admitted stroke patients, 21,129 (78.87%) had ischemic strokes and 5,662 (21.13 %) had hemorrhagic strokes. There were 14 (0.066%) ischemic and 1 hemorrhagic stroke (0.018%) patients included in this study. Of the recruited stroke patients, 64.29% had past heart disease history, especially atrial fibrillation (42.86%). Patients with fatal PE showed a significantly lower poststroke Glasgow Coma Scale (GCS) motor component than patients with nonfatal PE. Symptomatic PE is not common in stroke patients in Taiwan. Clinicians need to keep this fatal disease in mind, especially for persons with heart disease like atrial fibrillation. Stroke patients with impaired poststroke GCS motor components seemed to have a greater mortality risk if they have symptomatic PE.

Care for post-stroke patients at Malaysian public health centres: self-reported practices of family medicine specialists

PubMed Central

2014-01-01

Background Provision of post stroke care in developing countries is hampered by discoordination of services and limited access to specialised care. Albeit shortcomings, primary care continues to provide post-stroke services in less than favourable circumstances. This paper aimed to review provision of post-stroke care and related problems among Family Medicine Specialists managing public primary health care services. Methods A semi-structured questionnaire was distributed to 121 Family Physicians servicing public funded health centres in a pilot survey focused on improving post stroke care provision at community level. The questionnaire assessed respondents background and practice details i.e. estimated stroke care burden, current service provision and opinion on service improvement. Means and frequencies described quantitative data. For qualitative data, constant comparison method was used until saturation of themes was reached. Results Response rate of 48.8% was obtained. For every 100 patients seen at public healthcentres each month, 2 patients have stroke. Median number of stroke patients seen per month is 5 (IQR 2-10). 57.6% of respondents estimated total stroke patients treated per year at each centre was less than 40 patients. 72.4% lacked a standard care plan although 96.6% agreed one was needed. Patients seen were: discharged from tertiary care (88.1%), shared care plan with specialists (67.8%) and patients who developed stroke during follow up at primary care (64.4%). Follow-ups were done at 8-12 weekly intervals (60.3%) with 3.4% on ‘as needed’ basis. Referrals ranked in order of frequency were to physiotherapy services, dietitian and speech and language pathologists in public facilities. The FMS’ perceived 4 important ‘needs’ in managing stroke patients at primary care level; access to rehabilitation services, coordinated care between tertiary centres and primary care using multidisciplinary care approach, a standardized guideline and family and caregiver support. Conclusions Post discharge stroke care guidelines and access to rehabilitation services at primary care is needed for post stroke patients residing at home in the community. PMID:24580779

Development and validation of the Pediatric Stroke Quality of Life Measure.

PubMed

Fiume, Andrea; Deveber, Gabrielle; Jang, Shu-Hyun; Fuller, Colleen; Viner, Shani; Friefeld, Sharon

2018-06-01

To develop and validate a disease-specific parent proxy and child quality of life (QoL) measure for patients aged 2 to 18 years surviving cerebral sinovenous thrombosis (CSVT) and arterial ischaemic stroke (AIS). Utilizing qualitative and quantitative methods, we developed a 75-item Pediatric Stroke Quality of Life Measure (PSQLM) questionnaire. We mailed the PSQLM and a standardized generic QoL measure, Pediatric Quality of Life Inventory (PedsQL), to 353 families. Stroke type, age at stroke, and neurological outcome on the Pediatric Stroke Outcome Measure were documented. We calculated the internal consistency, validity, and reliability of the PSQLM. The response rate was 29%, yielding a sample of 101 patients (mean age 9y 9mo [SD 4.30]; 69 AIS [68.3%], 32 CSVT [31.7%]). The internal consistency of the PSQLM was high (Cronbach's α=0.94-0.97). Construct validity for the PSQLM was moderately strong (r=0.3-0.4; p<0.003) and, as expected, correlation with the PedsQL was moderate, suggesting the PSQLM operationalizes QoL distinct from the PedsQL. Test-retest reliability at 2 weeks was very good (intraclass correlation coefficient [ICC] 0.85-0.95; 95% confidence interval 0.83-0.97) and good agreement was established between parent and child report (ICC 0.63-0.76). The PSQLM demonstrates sound psychometric properties. Further research will seek to increase its clinical utility by reducing length and establishing responsiveness for descriptive and longitudinal evaluative assessment. A pediatric stroke-specific quality of life (QoL) measurement tool for assessments based on perceptions of importance and satisfaction. Moderate-to-high reliability and validity established for a new clinical scale evaluating QoL among children with stroke. Perceived QoL measured using the Pediatric Stroke Quality of Life Measure appears lower in children with neurological impairment. © 2018 Mac Keith Press.

Inter-rater reliability of kinesthetic measurements with the KINARM robotic exoskeleton.

PubMed

Semrau, Jennifer A; Herter, Troy M; Scott, Stephen H; Dukelow, Sean P

2017-05-22

Kinesthesia (sense of limb movement) has been extremely difficult to measure objectively, especially in individuals who have survived a stroke. The development of valid and reliable measurements for proprioception is important to developing a better understanding of proprioceptive impairments after stroke and their impact on the ability to perform daily activities. We recently developed a robotic task to evaluate kinesthetic deficits after stroke and found that the majority (~60%) of stroke survivors exhibit significant deficits in kinesthesia within the first 10 days post-stroke. Here we aim to determine the inter-rater reliability of this robotic kinesthetic matching task. Twenty-five neurologically intact control subjects and 15 individuals with first-time stroke were evaluated on a robotic kinesthetic matching task (KIN). Subjects sat in a robotic exoskeleton with their arms supported against gravity. In the KIN task, the robot moved the subjects' stroke-affected arm at a preset speed, direction and distance. As soon as subjects felt the robot begin to move their affected arm, they matched the robot movement with the unaffected arm. Subjects were tested in two sessions on the KIN task: initial session and then a second session (within an average of 18.2 ± 13.8 h of the initial session for stroke subjects), which were supervised by different technicians. The task was performed both with and without the use of vision in both sessions. We evaluated intra-class correlations of spatial and temporal parameters derived from the KIN task to determine the reliability of the robotic task. We evaluated 8 spatial and temporal parameters that quantify kinesthetic behavior. We found that the parameters exhibited moderate to high intra-class correlations between the initial and retest conditions (Range, r-value = [0.53-0.97]). The robotic KIN task exhibited good inter-rater reliability. This validates the KIN task as a reliable, objective method for quantifying kinesthesia after stroke.

Improving cognitive outcomes for pediatric stroke.

PubMed

Greenham, Mardee; Anderson, Vicki; Mackay, Mark T

2017-04-01

The past 20 years have seen a 35% increase in prevalence of pediatric stroke. Contrary to widely held views, children do not recover better than adults. This review explores the impact of pediatric stroke on cognitive domains, including intellectual and executive functions, memory and behavior, and the influence of age, lesion characteristics, and comorbidities on outcome. Cognitive problems occur in up to half of ischemic and hemorrhagic stroke survivors. Single-center studies have shown intelligence quotient scores skewed to the lower end of the average range, with greater impairment in performance than verbal domains. Executive function, such as attention and processing speed are particularly vulnerable to the effects of pediatric stroke. Age at stroke, larger infarct size, cortical/subcortical lesion location, epilepsy, and comorbid physical deficits are associated with poorer cognitive outcomes. Cognitive impairment occurs relatively frequently following pediatric stroke but the nature, severity, and predictors of specific deficits are not well defined. Improving understanding of outcomes following pediatric stroke is a key priority for families but a paucity of data limits the ability to develop targeted disease, and age-specific pediatric rehabilitation strategies to optimize cognitive outcomes following pediatric stroke.

Stroke management in northern Lombardy: organization of an emergency-urgency network and development of a connection between prehospital and in-hospital settings.

PubMed

Vidale, Simone; Verrengia, Elena; Gerardi, Francesca; Arnaboldi, Marco; Bezzi, Giacomo; Bono, Giorgio; Guidotti, Mario; Grampa, Giampiero; Perrone, Patrizia; Zarcone, Davide; Zoli, Alberto; Beghi, Ettore; Agostoni, Elio; Porazzi, Daniele; Landriscina, Mario

2012-08-01

Stroke is the leading cause of disability in adulthood, and the principal aim of care in cerebrovascular disease is the reduction of this negative outcome and mortality. Several studies demonstrated the efficacy of thrombolytic therapy in ischemic stroke, but up to 80% of cases could not be treated because the diagnostic workup exceeds the time limit. In this article, we described the design of a study conducted in the northern Lombardy, within the district of Sondrio, Lecco, Como, and Varese. The awaited results of this study are reduction of avoidable delay, organization of an operative stroke emergency network, and identification of highly specialized structures. The study schedules education and data registration with implementation and training of acute stroke management algorithms. The use of standardized protocols during prehospital and in-hospital phase can optimize acute stroke pathways. The results of this study could contribute to the assessment of an effective and homogeneous health system to manage acute stroke. © 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.

Kids Identifying and Defeating Stroke (KIDS): development and implementation of a multiethnic health education intervention to increase stroke awareness among middle school students and their parents.

PubMed

Mullen Conley, Kathleen; Juhl Majersik, Jennifer; Gonzales, Nicole R; Maddox, Katherine E; Pary, Jennifer K; Brown, Devin L; Moyé, Lemuel A; Espinosa, Nina; Grotta, James C; Morgenstern, Lewis B

2010-01-01

The Kids Identifying and Defeating Stroke (KIDS) project is a 3-year prospective, randomized, controlled, multiethnic school-based intervention study. Project goals include increasing knowledge of stroke signs and treatment and intention to immediately call 911 among Mexican American (MA) and non-Hispanic White (NHW) middle school students and their parents. This article describes the design, implementation, and interim evaluation of this theory-based intervention. Intervention students received a culturally appropriate stroke education program divided into four 50-minute classes each year during the sixth, seventh, and eighth grades. Each class session also included a homework assignment that involved the students' parents or other adult partners. Interim-test results indicate that this educational intervention was successful in improving students' stroke symptom and treatment knowledge and intent to call 911 upon witnessing a stroke compared with controls. The authors conclude that this school-based educational intervention to reduce delay time to hospital arrival for stroke shows early promise.

Paediatric stroke: pressing issues and promising directions.

PubMed

Kirton, Adam; deVeber, Gabrielle

2015-01-01

Stroke occurs across the lifespan with unique issues in the fetus, neonate, and child. The past decade has seen substantial advances in paediatric stroke research and clinical care, but many unanswered questions and controversies remain. The pathobiology of perinatal stroke needs to be better understood if prevention strategies are to be realised. Similarly, enhanced understanding of the mechanisms underlying childhood stroke, including cerebral arteriopathies, could inform the development of mechanism-specific treatments. Emerging clinical trials, including studies of neonatal sinovenous thrombosis and childhood arterial stroke, offer the hope of evidence-based treatment options in the near future. Early recognition of stroke in children is a key educational target for both the public and health-care professionals, and has translational potential to advance the application of neuroprotective, thrombolytic, and antithrombotic interventions and rehabilitation strategies to the earliest possible timepoints after stroke onset, improving outcomes and quality of life for affected children and their families. Copyright © 2015 Elsevier Ltd. All rights reserved.

Hip Hop Stroke: Study Protocol for a Randomized Controlled Trial to Address Stroke Literacy

PubMed Central

Williams, Olajide; Leighton-Herrmann, Ellyn; DeSorbo, Alexandra; Hecht, Mindy; Hedmann, Monique; Huq, Saima; Gerin, William; Chinchilli, Vernon; Ogedegbe, Gbenga; Noble, James

2015-01-01

Objective Stroke is the fifth leading cause of death and the leading cause of serious long-term adult disability in the US. Acute stroke treatments with intravenous thrombolysis and endovascular therapy are proven to reduce disability, however a critical limitation on their effectiveness is the narrow time window for administration, which is 4.5 hours and 6 hours respectively from the onset of symptoms. Our overarching goal is to reduce pre-hospital delays to acute stroke treatments in economically disadvantaged minority communities where the greatest delays exist, using Hip Hop Stroke. Methods Hip Hop Stroke (HHS) is a school-based, child-mediated, culturally-tailored stroke communication multimedia intervention developed using validated models of behavior change and designed to improve stroke literacy (knowledge of stroke symptoms, the urgent need to call 911, and prevention measures) of 4th, 5th and 6th grade students and their parents residing in poor urban communities. Children in the intervention arm will receive the HHS intervention, while those in the attentional control arm will receive standardized nutrition education based on the USDA's MyPyramid program. Children will be trained and motivated to share stroke information with their parents or other adult caregiver. Both children and parents will complete a stroke knowledge assessment at baseline, immediately following the program, and at 3-months post-program. The primary outcome is the effect of the child mediation on parental stroke literacy. Conclusion Stroke literate children, a captive audience in school systems, may represent a viable channel for spreading stroke information into households of poor urban communities where mass media stroke campaigns have shown the lowest penetration. These children may also call 911 when witnessing a stroke in their homes or communities. The HHS program may highlight the potential role of children in the chain of stroke recovery as a strategy for reducing prehospital delays to acute stroke treatment. PMID:26779395

Hip Hop Stroke: Study Protocol for a Randomized Controlled Trial to Address Stroke Literacy.

PubMed

Williams, Olajide; Leighton-Herrmann, Ellyn; DeSorbo, Alexandra; Hecht, Mindy; Hedmann, Monique; Huq, Saima; Gerin, William; Chinchilli, Vernon; Ogedegbe, Gbenga; Noble, James

2015-10-01

Stroke is the fifth leading cause of death and the leading cause of serious long-term adult disability in the US. Acute stroke treatments with intravenous thrombolysis and endovascular therapy are proven to reduce disability, however a critical limitation on their effectiveness is the narrow time window for administration, which is 4.5 hours and 6 hours respectively from the onset of symptoms. Our overarching goal is to reduce pre-hospital delays to acute stroke treatments in economically disadvantaged minority communities where the greatest delays exist, using Hip Hop Stroke. Hip Hop Stroke (HHS) is a school-based, child-mediated, culturally-tailored stroke communication multimedia intervention developed using validated models of behavior change and designed to improve stroke literacy (knowledge of stroke symptoms, the urgent need to call 911, and prevention measures) of 4 th , 5 th and 6 th grade students and their parents residing in poor urban communities. Children in the intervention arm will receive the HHS intervention, while those in the attentional control arm will receive standardized nutrition education based on the USDA's MyPyramid program. Children will be trained and motivated to share stroke information with their parents or other adult caregiver. Both children and parents will complete a stroke knowledge assessment at baseline, immediately following the program, and at 3-months post-program. The primary outcome is the effect of the child mediation on parental stroke literacy. Stroke literate children, a captive audience in school systems, may represent a viable channel for spreading stroke information into households of poor urban communities where mass media stroke campaigns have shown the lowest penetration. These children may also call 911 when witnessing a stroke in their homes or communities. The HHS program may highlight the potential role of children in the chain of stroke recovery as a strategy for reducing prehospital delays to acute stroke treatment.

Computed tomographic angiography in stroke imaging: fundamental principles, pathologic findings, and common pitfalls.

PubMed

Gupta, Rajiv; Jones, Stephen E; Mooyaart, Eline A Q; Pomerantz, Stuart R

2006-06-01

The development of multidetector row computed tomography (MDCT) now permits visualization of the entire vascular tree that is relevant for the management of stroke within 15 seconds. Advances in MDCT have brought computed tomography angiography (CTA) to the frontline in evaluation of stroke. CTA is a rapid and noninvasive modality for evaluating the neurovasculature. This article describes the role of CTA in the management of stroke. Fundamentals of contrast delivery, common pathologic findings, artifacts, and pitfalls in CTA interpretation are discussed.

Casemix and process indicators of outcome in stroke. The Royal College of Physicians minimum data set for stroke.

PubMed

Irwin, P; Rudd, A

1998-01-01

The emphasis on outcomes measurement requires that casemix is considered in any comparative studies. In 1996 the Intercollegiate Working Party for Stroke agreed a minimum data set to measure the severity of casemix in stroke. The reasons for its development, the evidence base supporting the items included and the possible uses of the data set are described. It is currently being evaluated in national outcome and process audits to be reported at a later date.

Delivering Knowledge of Stroke to Parents Through Their Children Using a Manga for Stroke Education in Elementary School.

PubMed

Ishigami, Akiko; Yokota, Chiaki; Nishimura, Kunihiro; Ohyama, Satoshi; Tomari, Shinya; Hino, Tenyu; Arimizu, Takuro; Wada, Shinichi; Toyoda, Kazunori; Minematsu, Kazuo

2017-02-01

School-based intervention would be promising to spread stroke knowledge widely. This study aimed to clarify the effectiveness of our new educational aids that were developed for elementary school children to impart information about stroke to children and their parents in 2 different ways: with or without stroke lessons by a neurologist. We enrolled 562 children (aged 11 to 12 years) and their parents (n = 485). The students were divided into 2 groups: 323 received a lesson on stroke by a stroke neurologist without watching an animated cartoon (Group I), and 239 watched an animated cartoon without the lesson (Group II). All of the children took the manga home, and talked about stroke with their parents. Questionnaires on stroke knowledge were administered at baseline (BL), immediately after the lesson (IL), and 3 months (3M) after the lesson. There were significant increases in the adjusted mean scores for risk factors as well as stroke symptoms at 3M in both groups compared with BL scores, although the children in Group I scored significantly better than those in Group II at IL and 3M (P < .05). In both children and parents, the correct answer rates of the FAST mnemonic at 3M were around 90%, with no significant differences between groups. Stroke education for elementary school children using our educational aids provided knowledge of stroke symptoms to the children as well as their parents even without lessons on stroke, although a better understanding of stroke was obtained from lessons led by stroke neurologists. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Trends in risk factors, patterns and causes in hospitalized strokes over 25 years: The Lausanne Stroke Registry.

PubMed

Carrera, Emmanuel; Maeder-Ingvar, Malin; Rossetti, Andrea O; Devuyst, Gérald; Bogousslavsky, Julien

2007-01-01

The Lausanne Stroke Registry includes, from 1979, all patients admitted to the department of Neurology of the Lausanne University Hospital with the diagnosis of first clinical stroke. Using the Lausanne Stroke Registry, we aimed to determine trends in risk factors, causes, localization and inhospital mortality over 25 years in hospitalized stroke patients. We assessed temporal trends in stroke patients characteristics through the following consecutive periods: 1979-1987, 1988-1995 and 1996-2003. Age-adjusted cardiovascular risk factors, etiologies, stroke localizations and mortality were compared between the three periods. Overall, 5,759 patients were included. Age was significantly different among the analyzed periods (p < 0.001), showing an increment in older patients throughout time. After adjustment for age, hypercholesterolemia increased (p < 0.001), as opposed to cigarette smoking (p < 0.001), hypertension (p < 0.001) and diabetes and hyperglycemia (p < 0.001). In patients with ischemic strokes, there were significant changes in the distribution of causes with an increase in cardioembolic strokes (p < 0.001), and in the localization of strokes with an increase in entire middle cerebral artery (MCA) and posterior circulation strokes together with a decrease in superficial middle cerebral artery stroke (p < 0.001). In patients with hemorrhagic strokes, the thalamic localizations increased, whereas the proportion of striatocapsular hemorrhage decreased (p = 0.022). Except in the older patient group, the mortality rate decreased. This study shows major trends in the characteristics of stroke patients admitted to a department of neurology over a 25-year time span, which may result from referral biases, development of acute stroke management and possibly from the evolution of cerebrovascular risk factors.

Inducible Glutamate Oxaloacetate Transaminase as a Therapeutic Target Against Ischemic Stroke

PubMed Central

Khanna, Savita; Briggs, Zachary

2015-01-01

Abstract Significance: Glutamate serves multi-faceted (patho)physiological functions in the central nervous system as the most abundant excitatory neurotransmitter and under pathological conditions as a potent neurotoxin. Regarding the latter, elevated extracellular glutamate is known to play a central role in ischemic stroke brain injury. Recent Advances: Glutamate oxaloacetate transaminase (GOT) has emerged as a new therapeutic target in protecting against ischemic stroke injury. Oxygen-sensitive induction of GOT expression and activity during ischemic stroke lowers glutamate levels at the stroke site while sustaining adenosine triphosphate levels in brain. The energy demands of the brain are among the highest of all organs underscoring the need to quickly mobilize alternative carbon skeletons for metabolism in the absence of glucose during ischemic stroke. Recent work builds on the important observation of Hans Krebs that GOT-mediated metabolism of glutamate generates tri-carboxylic acid (TCA) cycle intermediates in brain tissue. Taken together, outcomes suggest GOT may enable the transformative switch of otherwise excitotoxic glutamate into life-sustaining TCA cycle intermediates during ischemic stroke. Critical Issues: Neuroprotective strategies that focus solely on blocking mechanisms of glutamate-mediated excitotoxicity have historically failed in clinical trials. That GOT can enable glutamate to assume the role of a survival factor represents a paradigm shift necessary to develop the overall significance of glutamate in stroke biology. Future Directions: Ongoing efforts are focused to develop the therapeutic significance of GOT in stroke-affected brain. Small molecules that target induction of GOT expression and activity in the ischemic penumbra are the focus of ongoing studies. Antioxid. Redox Signal. 22, 175–186. PMID:25343301

Chromium supplementation improved post-stroke brain infarction and hyperglycemia.

PubMed

Chen, Wen-Ying; Mao, Frank Chiahung; Liu, Chia-Hsin; Kuan, Yu-Hsiang; Lai, Nai-Wei; Wu, Chih-Cheng; Chen, Chun-Jung

2016-04-01

Hyperglycemia is common after acute stroke and is associated with a worse outcome of stroke. Thus, a better understanding of stress hyperglycemia is helpful to the prevention and therapeutic treatment of stroke. Chromium is an essential nutrient required for optimal insulin activity and normal carbohydrate and lipid metabolism. Beyond its nutritional effects, dietary supplement of chromium causes beneficial outcomes against several diseases, in particular diabetes-associated complications. In this study, we investigated whether post-stroke hyperglycemia involved chromium dynamic mobilization in a rat model of permanent focal cerebral ischemia and whether dietary supplement of chromium improved post-stroke injury and alterations. Stroke rats developed brain infarction, hyperglycemia, hyperinsulinemia, glucose intolerance, and insulin resistance. Post-stroke hyperglycemia was accompanied by elevated secretion of counter-regulatory hormones including glucagon, corticosterone, and norepinephrine, decreased insulin signaling in skeletal muscles, and increased hepatic gluconeogenesis. Correlation studies revealed that counter-regulatory hormone secretion showed a positive correlation with chromium loss and blood glucose increased together with chromium loss. Daily chromium supplementation increased tissue chromium levels, attenuated brain infarction, improved hyperglycemia, and decreased plasma levels of glucagon and corticosterone in stroke rats. Our findings suggest that stroke rats show disturbance of tissue chromium homeostasis with a net loss through urinary excretion and chromium mobilization and loss might be an alternative mechanism responsible for post-stroke hyperglycemia.

Prediabetes is associated with post-stroke cognitive impairment in ischaemic stroke patients.

PubMed

Wang, Qiongzhang; Zhao, Kai; Cai, Yan; Tu, Xinjie; Liu, Yuntao; He, Jincai

2018-05-15

Diabetes mellitus is associated with post-stroke cognitive impairment. To the best of our knowledge, no study has explored the relationship between prediabetes and post-stroke cognitive impairment. The purpose of this study is to explore the association between prediabetes and cognitive impairment in ischaemic stroke patients at 1 month. Two hundred one acute ischaemic stroke patients were consecutively recruited within the first 24 h after admission and were followed up for 1 month. Patients were divided into a diabetes mellitus group, prediabetes group and non-diabetes mellitus group by fasting glucose levels, 2-h postprandial blood glucose levels and glycosylated haemoglobin levels at admission. Cognitive function was evaluated by the Mini-Mental State Examination at 1 month after stroke. The prediabetes group had a higher risk of post-stroke cognitive impairment than the non-diabetes group (35.7% vs. 18.1%, χ 2  = 4.252, P = .039). In logistical analyses, prediabetes was associated with post-stroke cognitive impairment after adjusting for potential confounding factors (odds ratio 3.062, 95% confidence interval 1.130-8.299, P = .028). Our findings show that prediabetes is associated with post-stroke cognitive impairment and may predict its development at 1 month post-stroke. Copyright © 2018 Elsevier B.V. All rights reserved.

Menopause and Stroke: An Epidemiologic Review

PubMed Central

Lisabeth, Lynda; Bushnell, Cheryl

2012-01-01

Although women have a lower risk of stroke during middle age, the menopausal transition is a time when many women develop cardiovascular risk factors. In addition, during the 10 years after menopause, the risk of stroke roughly doubles in women. Endogenous estrogen levels decline by 60% during the menopausal transition, leading to a relative androgen excess, which could contribute to the increased cardiovascular risk factors in women. Earlier onset of menopause may influence the risk of stroke, but the data are not clear. Because of the stroke risk associated with hormone therapy, this is only indicated for treatment of vasomotor symptoms, but some formulations may be safe than others. More research is needed to understand which women are at greatest stroke risk during midlife and to determine the safest formulation, dose, and duration of hormone therapy that will treat vasomotor symptoms without increasing the risk for stroke. PMID:22172623

The Use of Animal Models for Stroke Research: A Review

PubMed Central

Casals, Juliana B; Pieri, Naira CG; Feitosa, Matheus LT; Ercolin, Anna CM; Roballo, Kelly CS; Barreto, Rodrigo SN; Bressan, Fabiana F; Martins, Daniele S; Miglino, Maria A; Ambrósio, Carlos E

2011-01-01

Stroke has been identified as the second leading cause of death worldwide. Stroke is a focal neurologic deficit caused by a change in cerebral circulation. The use of animal models in recent years has improved our understanding of the physiopathology of this disease. Rats and mice are the most commonly used stroke models, but the demand for larger models, such as rabbits and even nonhuman primates, is increasing so as to better understand the disease and its treatment. Although the basic mechanisms of stroke are nearly identical among mammals, we here discuss the differences between the human encephalon and various animals. In addition, we compare common surgical techniques used to induce animal models of stroke. A more complete anatomic knowledge of the cerebral vessels of various model species is needed to develop more reliable models for objective results that improve knowledge of the pathology of stroke in both human and veterinary medicine. PMID:22330245

Treatment of Fever After Stroke: Conflicting Evidence

PubMed Central

Wrotek, Sylwia E.; Kozak, Wieslaw E.; Hess, David C.; Fagan, Susan C.

2014-01-01

Approximately 50% of patients hospitalized for stroke develop fever. In fact, experimental evidence suggests that high body temperature is significantly correlated to initial stroke severity, lesion size, mortality, and neurologic outcome. Fever occurring after stroke is associated with poor outcomes. We investigated the etiology of fever after stroke and present evidence evaluating the efficacy and safety of interventions used to treat stroke-associated fever. Oral antipyretics are only marginally effective in lowering elevated body temperature in this population and may have unintended adverse consequences. Nonpharmacologic approaches to cooling have been more effective in achieving normothermia, but whether stroke outcomes can be improved remains unclear. We recommend using body temperature as a biomarker and a catalyst for aggressive investigation for an infectious etiology. Care must be taken not to exceed the new standard of a maximum acetaminophen does of 3 g/day to avoid patient harm. PMID:22026396

In vivo animal stroke models: a rationale for rodent and non-human primate models

PubMed Central

Tajiri, Naoki; Dailey, Travis; Metcalf, Christopher; Mosley, Yusef I.; Lau, Tsz; Staples, Meaghan; van Loveren, Harry; Kim, Seung U.; Yamashima, Tetsumori; Yasuhara, Takao; Date, Isao; Kaneko, Yuji; Borlongan, Cesario V.

2013-01-01

On average, every four minutes an individual dies from a stroke, accounting for 1 out of every 18 deaths in the United States. Apporximately 795,000 Americans have a new or recurrent stroke each year, with just over 600,000 of these being first attack [1]. There have been multiple animal models of stroke demonstrating that novel therapeutics can help improve the clinical outcome. However, these results have failed to show the same outcomes when tested in human clinical trials. This review will discuss the current in vivo animal models of stroke, advantages and limitations, and the rationale for employing these animal models to satisfy translational gating items for examination of neuroprotective, as well as neurorestorative strategies in stroke patients. An emphasis in the present discussion of therapeutics development is given to stem cell therapy for stroke. PMID:23682299

Generating and measuring photochemical changes inside the brain using optical fibers: exploring stroke.

PubMed

Tsiminis, Georgios; Klarić, Thomas S; Schartner, Erik P; Warren-Smith, Stephen C; Lewis, Martin D; Koblar, Simon A; Monro, Tanya M

2014-11-01

We report here on the development of a method for inducing a stroke in a specific location within a mouse brain through the use of an optical fiber. By capturing the emitted fluorescence signal generated using the same fiber it is possible to monitor photochemical changes within the brain in real-time, and directly measure the concentration of the stroke-inducing dye, Rose Bengal, at the infarct site. This technique reduces the requirement for post-operative histology to determine if a stroke has successfully been induced within the animal, and therefore opens up the opportunity to explore the recovery of the brain after the stroke event.

The two-stroke poppet valve engine. Part 1: Intake and exhaust ports flow experimental assessments

NASA Astrophysics Data System (ADS)

Kamili Zahidi, M.; Razali Hanipah, M.; Ramasamy, D.; Noor, M. M.; Kadirgama, K.; Rahman, M. M.

2017-10-01

A two-stroke poppet valve engine is developed to overcome the common problems in conventional two-stroke engine designs. However, replacing piston control port with poppet valve will resulted different flow behaviour. This paper is looking at experimental assessment on a two-stroke poppet valve engine configuration to investigate the port flow performance. The aims are to evaluate the intake and exhaust coefficient of discharge and assess the twostroke capability of the cylinder head. The results has shown comparable coefficient of discharge values as production engine for the intake while the exhaust has higher values which is favourable for the two-stroke cycle operation.

Unobtrusive Estimation of Cardiac Contractility and Stroke Volume Changes Using Ballistocardiogram Measurements on a High Bandwidth Force Plate

PubMed Central

Ashouri, Hazar; Orlandic, Lara; Inan, Omer T.

2016-01-01

Unobtrusive and inexpensive technologies for monitoring the cardiovascular health of heart failure (HF) patients outside the clinic can potentially improve their continuity of care by enabling therapies to be adjusted dynamically based on the changing needs of the patients. Specifically, cardiac contractility and stroke volume (SV) are two key aspects of cardiovascular health that change significantly for HF patients as their condition worsens, yet these parameters are typically measured only in hospital/clinical settings, or with implantable sensors. In this work, we demonstrate accurate measurement of cardiac contractility (based on pre-ejection period, PEP, timings) and SV changes in subjects using ballistocardiogram (BCG) signals detected via a high bandwidth force plate. The measurement is unobtrusive, as it simply requires the subject to stand still on the force plate while holding electrodes in the hands for simultaneous electrocardiogram (ECG) detection. Specifically, we aimed to assess whether the high bandwidth force plate can provide accuracy beyond what is achieved using modified weighing scales we have developed in prior studies, based on timing intervals, as well as signal-to-noise ratio (SNR) estimates. Our results indicate that the force plate BCG measurement provides more accurate timing information and allows for better estimation of PEP than the scale BCG (r2 = 0.85 vs. r2 = 0.81) during resting conditions. This correlation is stronger during recovery after exercise due to more significant changes in PEP (r2 = 0.92). The improvement in accuracy can be attributed to the wider bandwidth of the force plate. ∆SV (i.e., changes in stroke volume) estimations from the force plate BCG resulted in an average error percentage of 5.3% with a standard deviation of ±4.2% across all subjects. Finally, SNR calculations showed slightly better SNR in the force plate measurements among all subjects but the small difference confirmed that SNR is limited by motion artifacts rather than instrumentation. PMID:27240380

Static Electric Fields and Lightning Over Land and Ocean in Florida Thunderstorms

NASA Technical Reports Server (NTRS)

Wilson, J. G.; Cummins, K. L.; Simpson, A. A.; Hinckley, A.

2017-01-01

Natural cloud-to-ground (CG) lightning and the charge structure of the associated clouds behave differently over land and ocean. Existing literature has raised questions over the years on the behavior of thunderstorms and lightning over oceans, and there are still open scientific questions. We expand on the observational datasets by obtaining identical electric field observations over coastal land, near-shore, and deep ocean regions during both clear air and thunderstorm periods. Oceanic observations were obtained using two 3-meter NOAA buoys that were instrumented with Campbell Scientific electric field mills to measure the static electric fields. These data were compared to selected electric field records from the existing on-shore electric field mill suite of 31 sensors at Kennedy Space Center (KSC). CG lightning occurrence times, locations and peak current values for both on-shore and ocean were provided by the U.S. National Lightning Detection Network. The buoy instruments were first evaluated on-shore at the Florida coast, to calibrate field enhancements and to confirm proper behavior of the system in elevated-field environments. The buoys were then moored 20NM and 120NM off the coast of KSC in February (20NM) and August (120NM) 2014. Statistically larger CG peak currents were reported over the deep ocean for first strokes and for subsequent strokes with new contacts points. Storm-related static fields were significantly larger at both oceanic sites, likely due to decreased screening by nearby space charge. Time-evolution of the static field during storm development and propagation indicated weak or missing lower positive charge regions in most storms that initiated over the deep ocean, supporting one mechanism for the observed high peak currents in negative first strokes over the deep ocean. This project also demonstrated the practicality of off-shore electric field measurements for safety-related decision making at KSC.

Predictors of Stroke and Coma After Neurosurgery: An ACS-NSQIP Analysis.

PubMed

Larsen, Alexandra M G; Cote, David J; Karhade, Aditya V; Smith, Timothy R

2016-09-01

The American College of Surgeons National Surgical Quality Improvement Program database aims to reduce 30-day postoperative complications. Reduction of postoperative stroke and coma can decrease length and cost of hospitalization, improve patient functional status, and decrease morbidity and mortality. We performed a search of the American College of Surgeons National Surgical Quality Improvement Program database for all patients from 2006 to 2013 undergoing an operation with a surgeon whose primary specialty was neurologic surgery. Of 94,546 neurosurgical patients reported, there were 687 (0.73%) cases of postoperative stroke and coma. The annual rate of coma longer than 24 hours decreased from 0.90% in 2006 to 0.002% in 2013 (P < 0.001), and the annual rate of stroke decreased from 1.2% in 2006 to 0.5% in 2013 (P = 0.013). Multivariate analysis showed that inpatient status (P = 0.001; odds ratio [OR], 30.3), age (P = 0.005; OR, 1.012), history of diabetes (P = 0.017; OR, 1.515), ventilator dependence (P < 0.001; OR, 4.379), impaired sensorium (P < 0.001; OR, 2.314), history of coma longer than 24 hours (P < 0.001; OR, 2.655), hemiparesis (P = 0.022; OR, 1.492), cerebrovascular accident/stroke with neurologic deficit (P < 0.001; OR, 2.091), cerebrovascular accident/stroke without neurologic deficit (P = 0.001; OR, 2.44), and tumor involving central nervous system (P < 0.001; OR, 2.928) are significant risk factors for developing postneurosurgical stroke and coma. The rate of postneurosurgical stroke decreased from 1.2% in 2006 to 0.5% in 2013 and the rate of postneurosurgical coma greater than 24 hours decreased from 0.9% in 2006 to 0.002% in 2013. Ten risk factors for developing postneurosurgical stroke and coma were identified using multivariable analysis. These risk factors should be assessed preoperatively and incorporated into clinical decision making so that individuals who are at higher risk for the development of stroke and coma can be appropriately monitored during the postoperative period. Copyright © 2016 Elsevier Inc. All rights reserved.

Using Delphi methodology in the development of a new patient-reported outcome measure for stroke survivors with visual impairment.

PubMed

Hepworth, Lauren R; Rowe, Fiona J

2018-02-01

The aim of this study was to ascertain what items stroke survivors and stroke care professionals think are important when assessing quality of life for stroke survivors with visual impairment for inclusion in the new patient-reported outcome measure. A reactive Delphi process was used in a three-round electronic-based survey. The items presented consisted of 62 items originally sourced from a systematic review of existing vision-related quality of life instruments and stroke survivor interviews, reduced and refined following a ranking exercise and pilot with stroke survivors with visual impairment. Stakeholders (stroke survivors/clinicians) were invited to take part in the process. A consensus definition of ≥70% was decided a priori. Participants were asked to rank importance on a 9-point scale and categorize the items by relevance to types of visual impairment following stroke or not relevant. Analysis of consensus, stability, and agreement was conducted. In total, 113 participants registered for the Delphi survey of which 47 (41.6%) completed all three rounds. Response rates to the three rounds were 78/113 (69.0%), 61/76 (81.3%), and 49/64 (76.6%), respectively. The participants included orthoptists (45.4%), occupational therapists (44.3%), and stroke survivors (10.3%). Consensus was reached on 56.5% of items in the three-round process, all for inclusion. A consensus was reached for 83.8% in the categorization of items. The majority (82.6%) of consensus were for relevant to 'all visual impairment following stroke'; two items were deemed 'not relevant'. The lack of item reduction achieved by this Delphi process highlights the need for additional methods of item reduction in the development of a new PROM for visual impairment following stroke. These results will be considered alongside Rasch analysis to achieve further item reduction. However, the Delphi survey remains important as it provides clinical and patient insight into each item rather than purely relying on the psychometric data.

Knowledge of stroke among stroke patients and their relatives in Northwest India.

PubMed

Pandian, Jeyaraj Durai; Kalra, Guneet; Jaison, Ashish; Deepak, Sukhbinder Singh; Shamsher, Shivali; Singh, Yashpal; Abraham, George

2006-06-01

The knowledge of warning symptoms and risk factors for stroke has not been studied among patients with stroke in developing countries. We aimed to assess the knowledge of stroke among patients with stroke and their relatives. Prospective tertiary referral hospital-based study in Northwest India. Trained nurses and medical interns interviewed patients with stroke and transient ischemic attack and their relatives about their knowledge of stroke symptoms and risk factors. Univariable and multivariable logistic regression were used. Of the 147 subjects interviewed, 102 (69%) were patients and 45 (31%) were relatives. There were 99 (67%) men and 48 (33%) women and the mean age was 59.7+/-14.1 years. Sixty-two percent of respondents recognized paralysis of one side as a warning symptom and 54% recognized hypertension as a risk factor for stroke. In the multivariable logistic regression analysis, higher education was associated with the knowledge of correct organ involvement in stroke (OR 2.6, CI 1.1- 6.1, P =0.02), whereas younger age (OR 2.7, CI 1.1-7.0, P =0.04) and higher education (OR 4.1, CI 1.5-10.9, P =0.005) correlated with a better knowledge regarding warning symptoms of stroke. In this study cohort, in general, there is lack of awareness of major warning symptoms, risk factors, organ involvement and self-recognition of stroke. However younger age and education status were associated with better knowledge. There is an urgent need for awareness programs about stroke in this study cohort.

Using the Two-Stroke Engine to Develop Technological Literacy

ERIC Educational Resources Information Center

Preble, Brian C.

2018-01-01

The two-stroke engine is an engineering marvel that has been incorporated into many aspects of modern-day life. While many seek to eliminate the two-stroke, others seek to revive this simple and effective power plant, aiming to make it more environmentally friendly and fuel-efficient. If successful, improvements could be far-reaching and…

Hypertension-Induced Vascular Remodeling Contributes to Reduced Cerebral Perfusion and the Development of Spontaneous Stroke in Aged SHRSP Rats

DTIC Science & Technology

2010-01-01

recanalization and reperfusion occurs in up to 50% of cases within 24 h of stroke onset ( Kassem -Moussa and Graffagnino, 2002; Merino et al, 2008...stroke-prone spontaneously hypertensive rat. Eur I Pharmacol574:158-71 Kassem -Moussa H, Graffagnino C (2002) Nonocclusion and spontaneous

Patterns of stroke recurrence according to subtype of first stroke event: the North East Melbourne Stroke Incidence Study (NEMESIS).

PubMed

Azarpazhooh, Mahmoud Reza; Nicol, Marcus B; Donnan, Geoffrey A; Dewey, Helen M; Sturm, Jonathan W; Macdonell, Richard A L; Pearce, Dora C; Thrift, Amanda G

2008-08-01

Specific information about the nature of recurrent events that occur after each subtype of index stroke may be useful for refining preventive therapies. We aimed to determine whether stroke recurrence rates, the pattern of subtype recurrence, and prescription of secondary prevention agents differed according to initial stroke subtype. Multiple overlapping sources were used to recruit all first-ever stroke patients from a geographically defined region of Melbourne, Australia over a 3-year period from 1996 to 1999. Potential stroke recurrences (fatal and nonfatal) occurring within 2 years of the initial event were identified following patient interview and follow up of death records. Subjects were classified into the different Oxfordshire groups and the type of first-ever stroke was compared with recurrent stroke events. One thousand, three hundred and sixteen first-ever strokes were registered during the 3-year period (mean age 74.4 years). A total of 103 first recurrent stroke events (fatal and nonfatal) occurred among those with a first-ever ischemic stroke or intracerebral hemorrhage (ICH) during the 2-year follow-up period. The recurrent stroke subtype was different to the index stroke subtype in most (78%) patients. People with partial anterior circulation infarct had the greatest proportion of recurrences (13%), with a third of these being the more severe total anterior circulation infarct subgroup. The relative risk of ICH after an index lacunar infarct (LACI) compared with an index non-LACI was 4.06 (95% CI 1.10-14.97, P=0.038). Prescription of secondary prevention agents was greater at 2 years after stroke than at hospital discharge, and was similar between ischemic stroke subtypes. Approximately 9% of people with first-ever stroke suffered a recurrent event, despite many being prescribed secondary prevention agents. This has implications for the uptake of current preventive strategies and the development of new strategies. The possibility that ICH is greater among index LACI cases needs to be confirmed.

A Method to Estimate the Probability That Any Individual Lightning Stroke Contacted the Surface Within Any Radius of Any Point

NASA Technical Reports Server (NTRS)

Huddleston, Lisa L.; Roeder, William; Merceret, Francis J.

2010-01-01

A technique has been developed to calculate the probability that any nearby lightning stroke is within any radius of any point of interest. In practice, this provides the probability that a nearby lightning stroke was within a key distance of a facility, rather than the error ellipses centered on the stroke. This process takes the current bivariate Gaussian distribution of probability density provided by the current lightning location error ellipse for the most likely location of a lightning stroke and integrates it to get the probability that the stroke is inside any specified radius. This new facility-centric technique will be much more useful to the space launch customers and may supersede the lightning error ellipse approach discussed in [5], [6].

[Preditive clinical factors for epileptic seizures after ischemic stroke].

PubMed

Fukujima, M M; Cardeal, J O; Lima, J G

1996-06-01

Preditive clinical factors for epileptic seizures after ischemic stroke. Clinical features of 35 patients with ischemic stroke who developed epilepsy (Group 1) were compared with those of 35 patients with ischemic stroke without epilepsy (Group 2). The age of the patients did not differ between the groups. There were more men than women and more white than other races in both groups. Diabetes melitus, hypertension, transient ischemic attack, previous stroke, migraine, Chagas disease, cerebral embolism of cardiac origin and use of oral contraceptive did not differ between the groups. Smokers and alcohol users were more frequent in Group 1 (p < 0.05). Most patients of Group 1 presented with hemiparesis; none presented cerebellar or brainstem involvement. Perhaps strokes in smokers have some different aspects, that let them more epileptogenic than in non smokers.

An adolescent with intact motor skills and intelligence after infant hemorrhagic stroke without rehabilitation therapy: a case report.

PubMed

Lee, Shenghuo; Yan, Tiebin; Lu, Xiao

2012-01-01

Devastating intracerebral hemorrhagic stroke is rarely encountered in children, but it has a high mortality rate. The case of a 15-year-old boy who survived a major stroke at 40 days old is described. He showed no significant motor or intelligence impairment in adolescence until he was hospitalized for transient left had tremors and slight left hand weakness caused by a cyst. The patient's almost complete motor recovery highlights the power of neural plasticity in young patients. The pediatric stroke was huge, but this did not affect his adolescent movement or intelligence, demonstrating the great neuroplastic potential of the developing human brain. These observations may help increase our knowledge about stroke in children and improve the treatment of pediatric stroke patients.

Anesthesia in Experimental Stroke Research

PubMed Central

Hoffmann, Ulrike; Sheng, Huaxin; Ayata, Cenk; Warner, David S.

2016-01-01

Anesthetics have enabled major advances in development of experimental models of human stroke. Yet their profound pharmacologic effects on neural function can confound the interpretation of experimental stroke research. Anesthetics have drug and dose-specific effects on cerebral blood flow and metabolism, neurovascular coupling, autoregulation, ischemic depolarizations, excitotoxicity, inflammation, neural networks, and numerous molecular pathways relevant for stroke outcome. Both pre- and post-conditioning properties have been described. Anesthetics also modulate systemic arterial blood pressure, lung ventilation, and thermoregulation, all of which may interact with the ischemic insult as well as the therapeutic interventions. These confounds present a dilemma. Here, we provide an overview of the anesthetic mechanisms of action and molecular and physiologic effects on factors relevant to stroke outcomes that can guide the choice and optimization of the anesthetic regimen in experimental stroke. PMID:27534542

Computational Pipeline for NIRS-EEG Joint Imaging of tDCS-Evoked Cerebral Responses-An Application in Ischemic Stroke.

PubMed

Guhathakurta, Debarpan; Dutta, Anirban

2016-01-01

Transcranial direct current stimulation (tDCS) modulates cortical neural activity and hemodynamics. Electrophysiological methods (electroencephalography-EEG) measure neural activity while optical methods (near-infrared spectroscopy-NIRS) measure hemodynamics coupled through neurovascular coupling (NVC). Assessment of NVC requires development of NIRS-EEG joint-imaging sensor montages that are sensitive to the tDCS affected brain areas. In this methods paper, we present a software pipeline incorporating freely available software tools that can be used to target vascular territories with tDCS and develop a NIRS-EEG probe for joint imaging of tDCS-evoked responses. We apply this software pipeline to target primarily the outer convexity of the brain territory (superficial divisions) of the middle cerebral artery (MCA). We then present a computational method based on Empirical Mode Decomposition of NIRS and EEG time series into a set of intrinsic mode functions (IMFs), and then perform a cross-correlation analysis on those IMFs from NIRS and EEG signals to model NVC at the lesional and contralesional hemispheres of an ischemic stroke patient. For the contralesional hemisphere, a strong positive correlation between IMFs of regional cerebral hemoglobin oxygen saturation and the log-transformed mean-power time-series of IMFs for EEG with a lag of about -15 s was found after a cumulative 550 s stimulation of anodal tDCS. It is postulated that system identification, for example using a continuous-time autoregressive model, of this coupling relation under tDCS perturbation may provide spatiotemporal discriminatory features for the identification of ischemia. Furthermore, portable NIRS-EEG joint imaging can be incorporated into brain computer interfaces to monitor tDCS-facilitated neurointervention as well as cortical reorganization.

Computational Pipeline for NIRS-EEG Joint Imaging of tDCS-Evoked Cerebral Responses—An Application in Ischemic Stroke

PubMed Central

Guhathakurta, Debarpan; Dutta, Anirban

2016-01-01

Transcranial direct current stimulation (tDCS) modulates cortical neural activity and hemodynamics. Electrophysiological methods (electroencephalography-EEG) measure neural activity while optical methods (near-infrared spectroscopy-NIRS) measure hemodynamics coupled through neurovascular coupling (NVC). Assessment of NVC requires development of NIRS-EEG joint-imaging sensor montages that are sensitive to the tDCS affected brain areas. In this methods paper, we present a software pipeline incorporating freely available software tools that can be used to target vascular territories with tDCS and develop a NIRS-EEG probe for joint imaging of tDCS-evoked responses. We apply this software pipeline to target primarily the outer convexity of the brain territory (superficial divisions) of the middle cerebral artery (MCA). We then present a computational method based on Empirical Mode Decomposition of NIRS and EEG time series into a set of intrinsic mode functions (IMFs), and then perform a cross-correlation analysis on those IMFs from NIRS and EEG signals to model NVC at the lesional and contralesional hemispheres of an ischemic stroke patient. For the contralesional hemisphere, a strong positive correlation between IMFs of regional cerebral hemoglobin oxygen saturation and the log-transformed mean-power time-series of IMFs for EEG with a lag of about −15 s was found after a cumulative 550 s stimulation of anodal tDCS. It is postulated that system identification, for example using a continuous-time autoregressive model, of this coupling relation under tDCS perturbation may provide spatiotemporal discriminatory features for the identification of ischemia. Furthermore, portable NIRS-EEG joint imaging can be incorporated into brain computer interfaces to monitor tDCS-facilitated neurointervention as well as cortical reorganization. PMID:27378836

More outcomes than trials: a call for consistent data collection across stroke rehabilitation trials.

PubMed

Ali, M; English, C; Bernhardt, J; Sunnerhagen, K S; Brady, M

2013-01-01

Stroke survivors experience complex combinations of impairments, activity limitations, and participation restrictions. The essential components of stroke rehabilitation remain elusive. Determining efficacy in randomized controlled trials (RCTs) is challenging; there is no commonly agreed primary outcome measure for rehabilitation trials. Clinical guidelines depend on proof of efficacy in RCTs and meta-analyses. However, diverse trial aims, differing methods, inconsistent data collection, and use of multiple assessment tools hinder comparability across trials. Consistent data collection in acute stroke trials has facilitated meta-analyses to inform trial design and clinical practice. With few exceptions, inconsistent data collection has hindered similar progress in stroke rehabilitation research. There is an urgent need for the routine collection of a core dataset of common variables in rehabilitation trials. The European Stroke Organisation Outcomes Working Group, the National Institutes of Neurological Disorders and Stroke Common Data Elements project, and the Collaborative Stroke Audit and Research project have called for consistency in data collection in stroke trials. Standardizing data collection can decrease study start up times, facilitate data sharing, and inform clinical guidelines. Although achieving consensus on which outcome measures to use in stroke rehabilitation trials is a considerable task, perhaps a feasible starting point is to achieve consistency in the collection of data on demography, stroke severity, and stroke onset to inclusion times. Longer term goals could include the development of a consensus process to establish the core dataset. This should be endorsed by researchers, funders, and journal editors in order to facilitate sustainable change. © 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.

Combinations of stroke neurorehabilitation to facilitate motor recovery: perspectives on Hebbian plasticity and homeostatic metaplasticity

PubMed Central

Takeuchi, Naoyuki; Izumi, Shin-Ichi

2015-01-01

Motor recovery after stroke involves developing new neural connections, acquiring new functions, and compensating for impairments. These processes are related to neural plasticity. Various novel stroke rehabilitation techniques based on basic science and clinical studies of neural plasticity have been developed to aid motor recovery. Current research aims to determine whether using combinations of these techniques can synergistically improve motor recovery. When different stroke neurorehabilitation therapies are combined, the timing of each therapeutic program must be considered to enable optimal neural plasticity. Synchronizing stroke rehabilitation with voluntary neural and/or muscle activity can lead to motor recovery by targeting Hebbian plasticity. This reinforces the neural connections between paretic muscles and the residual motor area. Homeostatic metaplasticity, which stabilizes the activity of neurons and neural circuits, can either augment or reduce the synergic effect depending on the timing of combination therapy and types of neurorehabilitation that are used. Moreover, the possibility that the threshold and degree of induced plasticity can be altered after stroke should be noted. This review focuses on the mechanisms underlying combinations of neurorehabilitation approaches and their future clinical applications. We suggest therapeutic approaches for cortical reorganization and maximal functional gain in patients with stroke, based on the processes of Hebbian plasticity and homeostatic metaplasticity. Few of the possible combinations of stroke neurorehabilitation have been tested experimentally; therefore, further studies are required to determine the appropriate combination for motor recovery. PMID:26157374

Early Rivaroxaban Use After Cardioembolic Stroke May Not Result in Hemorrhagic Transformation: A Prospective Magnetic Resonance Imaging Study.

PubMed

Gioia, Laura C; Kate, Mahesh; Sivakumar, Leka; Hussain, Dulara; Kalashyan, Hayrapet; Buck, Brian; Bussiere, Miguel; Jeerakathil, Thomas; Shuaib, Ashfaq; Emery, Derek; Butcher, Ken

2016-07-01

Early anticoagulation after cardioembolic stroke remains controversial because of the potential for hemorrhagic transformation (HT). We tested the safety and feasibility of initiating rivaroxaban ≤14 days after cardioembolic stroke/transient ischemic attack. A prospective, open-label study of patients with atrial fibrillation treated with rivaroxaban ≤14 days of transient ischemic attack or ischemic stroke (National Institute of Health Stroke Scale <9). All patients underwent magnetic resonance imaging <24 hours of rivaroxaban initiation and day 7. The primary end point was symptomatic HT at day 7. Sixty patients (mean±SD age 71±19 years, 82% stroke/18% transient ischemic attack) were enrolled. Median (interquartile range) time from onset to rivaroxaban was 3 (5) days. At treatment initiation, median National Institute of Health Stroke Scale was 2 (4), and median diffusion-weighted imaging volume was 7.9 (13.7) mL. At baseline, HT was present in 25 (42%) patients (hemorrhagic infarct [HI]1=19, HI2=6). On follow-up magnetic resonance imaging, no patients developed symptomatic HT. New asymptomatic HI1 developed in 3 patients, and asymptomatic progression from HI1 to HI2 occurred in 5 patients; otherwise, HT remained unchanged at day 7. These data support the safety of rivaroxaban initiation ≤14 days of mild-moderate cardioembolic stroke/transient ischemic attack. Magnetic resonance imaging evidence of petechial HT, which is common, does not appear to increase the risk of symptomatic HT. © 2016 American Heart Association, Inc.

What are the social consequences of stroke for working-aged adults? A systematic review.

PubMed

Daniel, Katie; Wolfe, Charles D A; Busch, Markus A; McKevitt, Christopher

2009-06-01

Approximately one fourth of strokes occur in people aged <65 years. UK current policy calls for services that meet the specific needs of working-aged adults with stroke. We aimed to identify the social consequences of stroke in working-aged adults, which might subsequently inform the development and evaluation of services for this group. We reviewed quantitative and qualitative studies identifying social consequences for working-aged adults with stroke using multiple search strategies (electronic databases, bibliographic references, hand searches). Social consequences were defined as those pertaining to the World Health Organization International Classification of Functioning, Disability and Health domain "participation." Two authors reviewed articles using a standardized matrix for data extraction. Seventy-eight studies were included: 66 were quantitative observational studies, 2 were quantitative interventional studies, 9 were qualitative studies, and one used mixed methods. Seventy studies reported data on return to work after stroke with proportions ranging from 0% to 100%. Other categories of social consequences included negative impact on family relationships (5% to 54%), deterioration in sexual life (5% to 76%), economic difficulties (24% to 33%), and deterioration in leisure activities (15% to 79%). Methodological variations account for the wide range of rates of return to work after stroke. There is limited evidence of the negative impact of stroke on other aspects of social participation. Robust estimates of the prevalence of such outcomes are required to inform the development of appropriate interventions. We propose strategies by which methodology and reporting in this field might be improved.

Stroke in young adults who abuse amphetamines or cocaine: a population-based study of hospitalized patients.

PubMed

Westover, Arthur N; McBride, Susan; Haley, Robert W

2007-04-01

The abuse of stimulant drugs is increasing in the western United States. Although numerous case reports and animal studies suggest a link with stroke, epidemiologic studies have yielded conflicting results. To test the hypothesis that young adults who abuse amphetamines or cocaine are at a higher risk of stroke. Using a cross-sectional design and from a quality indicators' database of 3 148 165 discharges from Texas hospitals, we estimated the secular trends from January 1, 2000, to December 31, 2003, in the abuse of various drugs and of strokes. We developed separate logistic regression models of risk factors for hemorrhagic (n = 937) and ischemic (n = 998) stroke discharges of persons aged 18 to 44 years in 2003, and for mortality risk in patients with stroke. Main Outcome Measure Incidence of stroke using definitions from the Agency for Healthcare Research and Quality's stroke mortality Inpatient Quality Indicator. From 2000 to 2003, the rate of increase was greatest for abuse of amphetamines, followed by cannabis and cocaine. The rate of strokes also increased, particularly among amphetamine abusers. In 812 247 discharges in 2003, amphetamine abuse was associated with hemorrhagic stroke (adjusted odds ratio [OR], 4.95; 95% confidence interval [CI], 3.24-7.55), but not with ischemic stroke; cocaine abuse was associated with hemorrhagic (OR, 2.33; 95% CI, 1.74-3.11) and ischemic (OR, 2.03; 95% CI, 1.48-2.79) stroke. Amphetamine, but not cocaine, abuse was associated with a higher risk of death after hemorrhagic stroke (OR, 2.63; 95% CI, 1.07-6.50). Increases in stimulant drug abuse may increase the rate of hospital admissions for strokes and stroke-related mortality.

Effects of ambient temperature on stroke hospital admissions: Results from a time-series analysis of 104,432 strokes in Guangzhou, China.

PubMed

Guo, Pi; Zheng, Murui; Feng, Wenru; Wu, Jiagang; Deng, Changyu; Luo, Ganfeng; Wang, Li; Pan, Bingying; Liu, Huazhang

2017-02-15

Stroke is a main cause of death and public health burden in China. The evidence on the burden of different strokes attack attribute to ambient temperature in China is limited. This study aimed to show the characteristics of stroke attack and the attributable risk due to temperature based on hospital admission data in Guangzhou, one of the most developed cities in China. From January 1, 2013 to December 31, 2015, 104,432 stroke hospitalizations in Guangzhou residents from 67 hospitals for stroke sentinel surveillance were registered. Characteristics of hospital admissions by gender, age group, calendar year and stroke subtype were analyzed, and distributed lag non-linear models were applied to evaluate the effects of temperature on stroke attack admissions. Stroke attack admissions increased from 31,851 to 36,755 through 2013 to 2015, increasing by 15.4%. An increasing trend in the risk of stroke attack with age was observed, irrespectively of stroke subtype and calendar year. People with hypertension were more likely to have an associated stroke than people without that. The effects of cold temperature on attack admissions for CBI and ICH strokes were significant. Overall, the percentages of CBI and ICH attack admissions attribute to cold temperature were 9.06% (95% CI: 1.84, 15.00) and 15.09% (95% CI: 5.86, 21.96), respectively. Besides, elderly people were more vulnerable to cold temperature than the young. Measures should be taken to increase public awareness about the ill effects of cold temperature on stroke attack, and educate the public about self-protection. Copyright © 2016 Elsevier B.V. All rights reserved.

Development of a Questionnaire to Investigate Study Design Factors Influencing Participation in Gait Rehabilitation Research by People with Stroke: A Brief Report.

PubMed

Patterson, Kara K; Gallant, Nicole; Ormiston, Tracey; Patience, Chad; Whitechurch, Mandy; Mansfield, Avril; Brown, Janet

2015-08-01

The main objective of this study was to evaluate the feasibility of a newly developed questionnaire to assess the influence of study design on participation in gait rehabilitation research in a pilot test with individuals with stroke. A secondary objective was to investigate the relationship between participation in gait rehabilitation research and social and clinical factors of interest after stroke. A questionnaire was developed with expert opinion and guidance from related previous research. The questionnaire was pilot tested in a group of 21 people with stroke, and social and clinical factors (including gait function) were collected. Gait function was assessed using a pressure-sensitive mat; social and clinical characteristics were extracted from patient charts. Correlations were performed to investigate relationships between questionnaire responses and gait function, motor impairment, and chronicity; t-tests were used to examine response differences between people with a caregiver at home and those without. A total of 21 people with stroke completed the questionnaire without difficulty; mean completion time was 7.2 (SD 3.5) minutes, with a range of responses across participants. Borderline significant associations were found between gait function and the number of studies in which a person would participate and between stroke chronicity and the location of studies in which a person would participate. A questionnaire to investigate the influence of study design factors on participation in rehabilitation research is feasible for administration in the post-stroke population and has potential to inform the design of future studies.

The experience of living with stroke and using technology: opportunities to engage and co-design with end users.

PubMed

Nasr, Nasrin; Leon, Beatriz; Mountain, Gail; Nijenhuis, Sharon M; Prange, Gerdienke; Sale, Patrizio; Amirabdollahian, Farshid

2016-11-01

We drew on an interdisciplinary research design to examine stroke survivors' experiences of living with stroke and with technology in order to provide technology developers with insight into values, thoughts and feelings of the potential users of a to-be-designed robotic technology for home-based rehabilitation of the hand and wrist. Ten stroke survivors and their family carers were purposefully selected. On the first home visit, they were introduced to cultural probe. On the second visit, the content of the probe packs were used as prompt to conduct one-to-one interviews with them. The data generated was analysed using thematic analysis. A third home visit was conducted to evaluate the early prototype. User requirements were categorised into their network of relationships, their attitude towards technology, their skills, their goals and motivations. The user requirements were used to envision the requirements of the system including providing feedback on performance, motivational aspects and usability of the system. Participants' views on the system requirements were obtained during a participatory evaluation. This study showed that prior to the development of technology, it is important to engage with potential users to identify user requirements and subsequently envision system requirements based on users' views. Implications for Rehabilitation An understanding of how stroke survivors make sense of their experiences of living with stroke is needed to design home-based rehabilitation technologies. Linking stroke survivors' goals, motivations, behaviour, feelings and attitude to user requirements prior to technology development has a significant impact on improving the design.

Development of early comprehensive stroke inpatient rehabilitation in Poland - current status and future requirements.

PubMed

Sarzyńska-Długosz, Iwona; Krawczyk, Maciej; Członkowska, Anna

2011-01-01

Every stroke patient should undergo early rehabilitation. We aimed to evaluate accessibility, development and needs in early stroke inpatient rehabilitation in Poland. A questionnaire evaluating rehabilitation departments was prepared and sent (in 2004 and 2008) to rehabilitation wards in Poland, where stroke patients are treated and undergo early rehabilitation. We divided departments into classes: class A - having comprehensive rehabilitation (physiotherapy minimum 60 minutes/day, speech therapy minimum 30 minutes/5 days/week, rehabilitation of other cognitive impairments minimum 30 minutes/5 days/week, group physiotherapy); B - having the possibility of all types of therapy, but done less frequently; C - physiotherapy and speech therapy; D - physiotherapy and cognitive rehabilitation; E - only physiotherapy. In 2004, we obtained responses from 115 of 172 (66.9%) rehabilitation departments. According to prespecified criteria there were 11 class A, 31 class B, 28 class C, 4 class D, and 41 class E wards. In 2008, we received response from 89 of 149 (59.7%) rehabilitation departments. According to prespecified criteria there were 17 class A, 40 class B, 22 class C, 0 class D, and 10 class E wards. In 2004, 159 beds and in 2008, 294 beds in class A departments were available for stroke patients. The minimal number of needed but lacking beds was 604 in 2004 and 469 in 2008. Development of departments providing early comprehensive stroke rehabilitation from 2004 to 2008 is marked, but still insufficient. In 2008, 19% of rehabilitation departments could provide comprehensive stroke rehabilitation and this was 38.5% of beds actually needed.

A hemicyanine based ratiometric fluorescence probe for mapping lysosomal pH during heat stroke in living cells.

PubMed

Wu, Luling; Wang, Yang; James, Tony D; Jia, Nengqin; Huang, Chusen

2018-05-29

Heat stroke is a lethal condition which can cause dysfunction in the central nervous system, multi-organ damage and even death. However, there is still limited knowledge of the detailed mechanism about the roles of lysosomes in heat stroke due to lack of effective tools. Herein, we introduce our previously developed hemicyanine with a large D-π-A structure as the key fluorophore to develop a new fluorescent probe (CPY) for ratiometric mapping of lysosomal pH changes in live cells under a heat shock stimulus.

Use of virtual reality to promote hand therapy post-stroke

NASA Astrophysics Data System (ADS)

Tsoupikova, Daria; Stoykov, Nikolay; Vick, Randy; Li, Yu; Kamper, Derek; Listenberger, Molly

2013-03-01

A novel artistic virtual reality (VR) environment was developed and tested for use as a rehabilitation protocol for post-stroke hand rehabilitation therapy. The system was developed by an interdisciplinary team of engineers, art therapists, occupational therapists, and VR artists to improve patients' motivation and engagement. Specific exercises were developed to explicitly promote the practice of therapeutic tasks requiring hand and arm coordination for upper extremity rehabilitation. Here we describe system design, development, and user testing for efficiency, subject's satisfaction and clinical feasibility. We report results of the completed qualitative, pre-clinical pilot study of the system effectiveness for therapy. Fourteen stroke survivors with chronic hemiparesis participated in a single training session within the environment to gauge user response to the protocol through a custom survey. Results indicate that users found the system comfortable, enjoyable, tiring; instructions clear, and reported a high level of satisfaction with the VR environment and rehabilitation task variety and difficulty. Most patients reported very positive impressions of the VR environment and rated it highly, appreciating its engagement and motivation. We are currently conducting a longitudinal intervention study over 6 weeks in stroke survivors with chronic hemiparesis. Initial results following use of the system on the first subjects demonstrate that the system is operational and can facilitate therapy for post stroke patients with upper extremity impairment.

Prevalence, incidence, and factors associated with pre-stroke and post-stroke dementia: a systematic review and meta-analysis.

PubMed

Pendlebury, Sarah T; Rothwell, Peter M

2009-11-01

Reliable data on the prevalence and predictors of post-stroke dementia are needed to inform patients and carers, plan services and clinical trials, ascertain the overall burden of stroke, and understand its causes. However, published data on the prevalence and risk factors for pre-stroke and post-stroke dementia are conflicting. We undertook this systematic review to assess the heterogeneity in the reported rates and to identify risk factors for pre-stroke and post-stroke dementia. Studies published between 1950 and May 1, 2009, were identified from bibliographic databases, reference lists, and journal contents pages. Studies were included if they were on patients with symptomatic stroke, were published in English, reported on a series of consecutive eligible patients or volunteers in prospective cohort studies, included all stroke or all ischaemic stroke, measured dementia by standard criteria, and followed up patients for at least 3 months after stroke. Pooled rates of dementia were stratified by study setting, inclusion or exclusion of pre-stroke dementia, and by first, any, or recurrent stroke. Pooled odds ratios were calculated for factors associated with pre-stroke and post-stroke dementia. We identified 22 hospital-based and eight population-based eligible cohorts (7511 patients) described in 73 papers. The pooled prevalence of pre-stroke dementia was higher (14.4%, 95% CI 12.0-16.8) in hospital-based studies than in population-based studies (9.1%, 6.9-11.3). Although post-stroke (

Development of a Mobile Tool That Semiautomatically Screens Patients for Stroke Clinical Trials.

PubMed

Spokoyny, Ilana; Lansberg, Maarten; Thiessen, Rosita; Kemp, Stephanie M; Aksoy, Didem; Lee, YongJae; Mlynash, Michael; Hirsch, Karen G

2016-10-01

Despite several national coordinated research networks, enrollment in many cerebrovascular trials remains challenging. An electronic tool was needed that would improve the efficiency and efficacy of screening for multiple simultaneous acute clinical stroke trials by automating the evaluation of inclusion and exclusion criteria, improving screening procedures and streamlining the communication process between the stroke research coordinators and the stroke clinicians. A multidisciplinary group consisting of physicians, study coordinators, and biostatisticians designed and developed an electronic clinical trial screening tool on a HIPAA (Health Insurance Portability and Accountability Act)-compliant platform. A web-based tool was developed that uses branch logic to determine eligibility for simultaneously enrolling clinical trials and automatically notifies the study coordinator teams about eligible patients. After 12 weeks of use, 225 surveys were completed, and 51 patients were enrolled in acute stroke clinical trials. Compared with the 12 weeks before implementation of the tool, there was an increase in enrollment from 16.5% of patients screened to 23.4% of patients screened (P<0.05). Clinicians and coordinators reported increased satisfaction with the process and improved ease of screening. We created a semiautomated electronic screening tool that uses branch logic to screen patients for stroke clinical trials. The tool has improved efficiency and efficacy of screening, and it could be adapted for use at other sites and in other medical fields. © 2016 American Heart Association, Inc.

The level of awareness of stroke risk factors and symptoms in the Gulf Cooperation Council countries: Gulf Cooperation Council stroke awareness study.

PubMed

Kamran, S; Bener, A B; Deleu, D; Khoja, W; Jumma, M; Al Shubali, A; Inshashi, J; Sharouqi, I; Al Khabouri, J

2007-01-01

To assess the knowledge of stroke in the general public in the Gulf Cooperation Council (GCC) countries. The Arabian Gulf is a rapidly developing part of the world with major changes in the lifestyle that can increase the risk of stroke. To design effective stroke treatment and prevention strategies, an assessment of the public knowledge of stroke is required. A cross-sectional community-based survey was conducted at primary health care centers (PHCs), in urban and semi-urban areas, of the GCC countries (Qatar, Saudi Arabia, Kuwait, Bahrain, the United Arab Emirates, Oman) on the level of stroke awareness in the general public. Health care workers completed 3,750 face-to-face interviews. 1,089 (29.0%) were familiar with the term 'stroke', and 29.3% considered the age group 30-50 at the highest risk for stroke. The commonest risk factors identified were hypertension (23.1%) and smoking (27.3%). People who did not know the term stroke had a higher incidence of diabetes, hypertension, and had more than one risk factor (p < 0.05). The most frequently identified stroke symptoms were weakness (23%) and speech problems (21.7%). Of those who recognized stroke, blockage of blood vessels was identified as the commonest cause of stroke (22%) followed by tension/worrying (20%). Doctors and nurses were regarded as the best source of stroke information (70%). In the univariate comparison, younger age (p < 0.001), higher level of education (p < 0.001), and female gender (p = 0.008) better predicted stroke recognition. In a multivariate logistic regression analysis, the level of education, monthly income and smoking were independent variables predicting stroke knowledge. The majority of the patients had not even heard the term stroke. Stroke knowledge was poorest among the groups that were at the highest risk for stroke. Stroke education has to focus on the high-risk groups, particularly the younger population. The health care workers at the PHCs and hospitals will need instructions on providing stroke information to the public. The level of knowledge of stroke risk factors and symptoms emphasizes the need for stroke education efforts in the community. (c) 2008 S. Karger AG, Basel.

The Alberta Stroke Prevention in TIAs and mild strokes (ASPIRE) intervention: rationale and design for evaluating the implementation of a province-wide TIA triaging system.

PubMed

Jeerakathil, Thomas; Shuaib, Ashfaq; Majumdar, Sumit R; Demchuk, Andrew M; Butcher, Kenneth S; Watson, Tim J; Dean, Naeem; Gordon, Deb; Edmond, Cathy; Coutts, Shelagh B

2014-10-01

Stroke risk after transient ischaemic attack is high and, it is a challenge worldwide to provide urgent assessment and preventive services to entire populations. To determine whether a province-wide transient ischaemic attack Triaging algorithm and transient ischaemic attack hotline (the Alberta Stroke Prevention in transient ischaemic attacks and mild strokes intervention) can reduce the rate of stroke recurrence following transient ischaemic attack across the population of Alberta, Canada (population 3·7 million, 90-day rate of post-stroke transient ischaemic attack currently 9·5%). It also seeks to improve upon current transient ischaemic attack triaging rules by incorporating time from symptom onset as a predictive variable. The transient ischaemic attack algorithm and hotline were developed with a broad consensus of clinicians, patients, policy-makers, and researchers and based on local adaptation of the work of others and research and insights developed within the province. Because neither patient-level nor region-level randomization was possible, we conducted a quasi-experimental design examining changes in the post-transient ischaemic attack rate of stroke recurrence before and after the 15-month implementation period using an interrupted time-series regression analysis. The design controls for changes in case-mix, co-interventions, and secular trends. A prospective transient ischaemic attack cohort will also be concurrently created with telephone follow-up at seven-days and 90 days as well as passive follow-up over the longer term using linkages to provincial healthcare administrative databases. The primary outcome measure is the change in recurrence rate of stroke following transient ischaemic attack at seven-days and 90 days, comparing a period of two-years before vs. two-years after the intervention is implemented. All cases of recurrent stroke will be validated. Secondary outcomes include functional status, hospitalizations, morbidity, and mortality. We are undertaking a rigorous evaluation of a population-based approach to improving quality of transient ischaemic attack care. Whether positive or negative, our work should provide important insights for all potential stakeholders. © 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.

Volunteer Stroke Service (VSS) groups for patients with communication difficulties after stroke: a qualitative analysis of the value of groups to their users.

PubMed

Legg, Lynn; Stott, David; Ellis, Graham; Sellars, Cameron

2007-09-01

To identify the functions that Volunteer Stroke Service (VSS) groups fulfil for their members. Qualitative focus group study. Mixed urban and rural community settings in Scotland. Seven focus groups comprising a total of 24 men and 14 women, with dysarthria or aphasia following stroke, who were members of VSS groups funded by Chest Heart and Stroke Scotland. We identified eight main themes. VSS groups (1) include members in an interpersonal network, (2) provide members with the opportunity to develop interpersonal relations, (3) provide members with support, (4) provide opportunities for personal growth and development, (5) supply members with a purpose, structure and routine, (6) help members establish and confirm their identify, beliefs and values, (7) help members accomplish individual and shared goals, and (8) provide members with the opportunity to influence others and be influenced. VSS groups appear to provide a range of functions that meet members' personal, interpersonal and psychological needs.

Barriers and facilitators to staying in work after stroke: insight from an online forum.

PubMed

Balasooriya-Smeekens, Chantal; Bateman, Andrew; Mant, Jonathan; De Simoni, Anna

2016-04-06

To explore barriers and facilitators to staying in work following stroke. Qualitative analysis of posts regarding staying in work following stroke using the archives of an online forum for stroke survivors. 60 stroke survivors (29 male, 23 female, 8 not stated; mean age at stroke 44 years) who have returned to work, identified using terms 'return to work' and 'back at work'. Posts from UK stroke survivors and family members on Talkstroke, the forum of the Stroke Association, between 2004 and 2011. Stroke and transient ischaemic attack (TIA) survivors reported residual impairments that for many had impact on work. Most impairments were 'invisible', including fatigue, problems with concentration, memory and personality changes. Participants described positive (eg, back at work being better than expected) and negative work experiences, including being at risk of losing the job because of stroke-related impairments. Barriers to successfully staying in work included lack of understanding of stroke--in particular invisible impairments--of survivors, employers and general practitioners (GPs), and lack of support in terms of formal adjustments, and 'feeling supported'. Stroke survivors described how they developed their own coping strategies, and how workplace and employer helped them to stay in work. Despite having been able to return to work after a stroke, people may still experience difficulties in staying in work and risking losing their job. There is a need to improve awareness, in particular of invisible stroke-related impairments, among stroke survivors, work personnel and clinicians. This might be achieved through improved assessments of residual impairments in the workplace and in general practice. Future studies should investigate the effect of unrecognised fatigue and invisible impairments on staying in work following stroke, and explore the potential role for primary care in supporting stroke survivors who have returned to employment. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Stroke Location Is an Independent Predictor of Cognitive Outcome.

PubMed

Munsch, Fanny; Sagnier, Sharmila; Asselineau, Julien; Bigourdan, Antoine; Guttmann, Charles R; Debruxelles, Sabrina; Poli, Mathilde; Renou, Pauline; Perez, Paul; Dousset, Vincent; Sibon, Igor; Tourdias, Thomas

2016-01-01

On top of functional outcome, accurate prediction of cognitive outcome for stroke patients is an unmet need with major implications for clinical management. We investigated whether stroke location may contribute independent prognostic value to multifactorial predictive models of functional and cognitive outcomes. Four hundred twenty-eight consecutive patients with ischemic stroke were prospectively assessed with magnetic resonance imaging at 24 to 72 hours and at 3 months for functional outcome using the modified Rankin Scale and cognitive outcome using the Montreal Cognitive Assessment (MoCA). Statistical maps of functional and cognitive eloquent regions were derived from the first 215 patients (development sample) using voxel-based lesion-symptom mapping. We used multivariate logistic regression models to study the influence of stroke location (number of eloquent voxels from voxel-based lesion-symptom mapping maps), age, initial National Institutes of Health Stroke Scale and stroke volume on modified Rankin Scale and MoCA. The second part of our cohort was used as an independent replication sample. In univariate analyses, stroke location, age, initial National Institutes of Health Stroke Scale, and stroke volume were all predictive of poor modified Rankin Scale and MoCA. In multivariable analyses, stroke location remained the strongest independent predictor of MoCA and significantly improved the prediction compared with using only age, initial National Institutes of Health Stroke Scale, and stroke volume (area under the curve increased from 0.697-0.771; difference=0.073; 95% confidence interval, 0.008-0.155). In contrast, stroke location did not persist as independent predictor of modified Rankin Scale that was mainly driven by initial National Institutes of Health Stroke Scale (area under the curve going from 0.840 to 0.835). Similar results were obtained in the replication sample. Stroke location is an independent predictor of cognitive outcome (MoCA) at 3 months post stroke. © 2015 American Heart Association, Inc.

The mobilize center: an NIH big data to knowledge center to advance human movement research and improve mobility.

PubMed

Ku, Joy P; Hicks, Jennifer L; Hastie, Trevor; Leskovec, Jure; Ré, Christopher; Delp, Scott L

2015-11-01

Regular physical activity helps prevent heart disease, stroke, diabetes, and other chronic diseases, yet a broad range of conditions impair mobility at great personal and societal cost. Vast amounts of data characterizing human movement are available from research labs, clinics, and millions of smartphones and wearable sensors, but integration and analysis of this large quantity of mobility data are extremely challenging. The authors have established the Mobilize Center (http://mobilize.stanford.edu) to harness these data to improve human mobility and help lay the foundation for using data science methods in biomedicine. The Center is organized around 4 data science research cores: biomechanical modeling, statistical learning, behavioral and social modeling, and integrative modeling. Important biomedical applications, such as osteoarthritis and weight management, will focus the development of new data science methods. By developing these new approaches, sharing data and validated software tools, and training thousands of researchers, the Mobilize Center will transform human movement research. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association.

An investigation of fluid flow during induction stroke of a water analog model of an IC engine using an innovative optical velocimetry concept: LIPA

NASA Technical Reports Server (NTRS)

Stier, Bernd; Falco, R. E.

1994-01-01

Optical measurements on an axisymmetrical quartz component engine research model were made to evaluate the flow field encountered during induction. The measurement technique is LIPA (Laser Induced Photochemical Anemometry), a non-intrusive velocimetry concept that provides an investigator of fluid flow with a tool to attain planar information about three-dimensional velocity and vorticity vectors in a single measurement step. The goal of this investigation is to further develop this measurement technique and apply it to study the induction stroke of a water analog model of a four-stroke internal combustion engine. The research conducted in the water analog model is a fundamental scientific inquiry into the flow fields that develop in the induction stroke of an engine at idling engine speeds. As this is the first investigation of its kind using LIPA technique, our goal has been to quantify, in a preliminary manner, the flow field features that develop during the intake stroke. In the process a more comprehensive understanding of the flow field features was developed, and tied to the quantification. The study evaluated the flow field of the intake stroke by estimating fields of velocity and vorticity. On the basis of these data, information about fluid dynamics during induction at engine speeds of 10, 20, and 30 RPM (corresponding to 170, 340, and 510 RPM respectively, when air is the flowing medium) for three different valve lifts was obtained. The overall development of the flow field, its energy content (kinetic, fluctuation) for the different settings of the engine parameters, vorticity information, and cyclic variations have been quantified. These have been discussed in terms of mixing performance.

Flex-Fuel Two-Stroke Snowmobile: Development of a Flex-Fuel, Two-Stroke, Direct-Injection Snowmobile for Use in the Clean Snowmobile Challenge and National Parks

DOT National Transportation Integrated Search

2009-09-01

The University of Idaho's entry into the 2009 SAE Clean Snowmobile Challenge (CSC) was a semi-direct-injection (SDI) two-stroke powered REV-XP snowmobile modified to use flex fuel. The flex fuel engine produces stock engine power on any blend of etha...

Development of a Multidimensional Index for Assessing Social Support in Rehabilitation.

ERIC Educational Resources Information Center

McColl, Mary Ann; Friedland, Judith

1989-01-01

Discusses the development and psychometric evaluation of the Social Support Inventory for Stroke Survivors, a multidimensional instrument for measuring social support and its influence on the rehabilitation of stroke patients. Examines the test-retest reliability and internal consistency of the instrument and suggests modifications and clinical…

An interactive distance solution for stroke rehabilitation in the home setting - A feasibility study.

PubMed

Palmcrantz, Susanne; Borg, Jörgen; Sommerfeld, Disa; Plantin, Jeanette; Wall, Anneli; Ehn, Maria; Sjölinder, Marie; Boman, Inga-Lill

2017-09-01

In this study an interactive distance solution (called the DISKO tool) was developed to enable home-based motor training after stroke. The overall aim was to explore the feasibility and safety of using the DISKO-tool, customized for interactive stroke rehabilitation in the home setting, in different rehabilitation phases after stroke. Fifteen patients in three different stages in the continuum of rehabilitation after stroke participated in a home-based training program using the DISKO-tool. The program included 15 training sessions with recurrent follow-ups by the integrated application for video communication with a physiotherapist. Safety and feasibility were assessed from patients, physiotherapists, and a technician using logbooks, interviews, and a questionnaire. Qualitative content analysis and descriptive statistics were used in the analysis. Fourteen out of 15 patients finalized the training period with a mean of 19.5 minutes spent on training at each session. The DISKO-tool was found to be useful and safe by patients and physiotherapists. This study demonstrates the feasibility and safety of the DISKO-tool and provides guidance in further development and testing of interactive distance technology for home rehabilitation, to be used by health care professionals and patients in different phases of rehabilitation after stroke.

Development and initial psychometric evaluation of an item bank created to measure upper extremity function in persons with stroke.

PubMed

Higgins, Johanne; Finch, Lois E; Kopec, Jacek; Mayo, Nancy E

2010-02-01

To create and illustrate the development of a method to parsimoniously and hierarchically assess upper extremity function in persons after stroke. Data were analyzed using Rasch analysis. Re-analysis of data from 8 studies involving persons after stroke. Over 4000 patients with stroke who participated in various studies in Montreal and elsewhere in Canada. Data comprised 17 tests or indices of upper extremity function and health-related quality of life, for a total of 99 items related to upper extremity function. Tests and indices included, among others, the Box and Block Test, the Nine-Hole Peg Test and the Stroke Impact Scale. Data were collected at various times post-stroke from 3 days to 1 year. Once the data fit the model, a bank of items measuring upper extremity function with persons and items organized hierarchically by difficulty and ability in log units was produced. This bank forms the basis for eventual computer adaptive testing. The calibration of the items should be tested further psychometrically, as should the interpretation of the metric arising from using the item calibration to measure the upper extremity of individuals.

Delayed-onset dementia after stroke or transient ischemic attack.

PubMed

Mok, Vincent C T; Lam, Bonnie Y K; Wang, Zhaolu; Liu, Wenyan; Au, Lisa; Leung, Eric Y L; Chen, Sirong; Yang, Jie; Chu, Winnie C W; Lau, Alexander Y L; Chan, Anne Y Y; Shi, Lin; Fan, Florence; Ma, Sze H; Ip, Vincent; Soo, Yannie O Y; Leung, Thomas W H; Kwok, Timothy C Y; Ho, Chi L; Wong, Lawrence K S; Wong, Adrian

2016-11-01

Patients surviving stroke without immediate dementia are at high risk of delayed-onset dementia. Mechanisms underlying delayed-onset dementia are complex and may involve vascular and/or neurodegenerative diseases. Dementia-free patients with stroke and/or transient ischemic attack (TIA; n = 919) were studied for 3 years prospectively, excluding those who developed dementia 3 to 6 months after stroke and/or TIA. Forty subjects (4.4%) developed dementia during the study period. Imaging markers of severe small vessel disease (SVD), namely presence of ≥3 lacunes and confluent white matter changes; history of hypertension and diabetes mellitus independently predicted delayed-onset dementia after adjustment for age, gender, and education. Only 6 of 31 (19.4%) subjects with delayed cognitive decline harbored Alzheimer's disease-like Pittsburg compound B (PiB) retention. Most PiB cases (16/25, 64%) had evidence of severe SVD. Severe SVD contributes importantly to delayed-onset dementia after stroke and/or TIA. Future clinical trials aiming to prevent delayed-onset dementia after stroke and/or TIA should target this high-risk group. Copyright © 2016 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

STARTING-SICH Nomogram to Predict Symptomatic Intracerebral Hemorrhage After Intravenous Thrombolysis for Stroke.

PubMed

Cappellari, Manuel; Turcato, Gianni; Forlivesi, Stefano; Zivelonghi, Cecilia; Bovi, Paolo; Bonetti, Bruno; Toni, Danilo

2018-02-01

Symptomatic intracerebral hemorrhage (sICH) is a rare but the most feared complication of intravenous thrombolysis for ischemic stroke. We aimed to develop and validate a nomogram for individualized prediction of sICH in intravenous thrombolysis-treated stroke patients included in the multicenter SITS-ISTR (Safe Implementation of Thrombolysis in Stroke-International Stroke Thrombolysis Register). All patients registered in the SITS-ISTR by 179 Italian centers between May 2001 and March 2016 were originally included. The main outcome measure was sICH per the European Cooperative Acute Stroke Study II definition (any type of intracerebral hemorrhage with increase of ≥4 National Institutes of Health Stroke Scale score points from baseline or death <7 days). On the basis of multivariate logistic model, the nomogram was generated. We assessed the discriminative performance by using the area under the receiver-operating characteristic curve and calibration of risk prediction model by using the Hosmer-Lemeshow test. A total of 15 949 patients with complete data for generating the nomogram was randomly dichotomized into training (3/4; n=12 030) and test (1/4; n=3919) sets. After multivariate logistic regression, 10 variables remained independent predictors of sICH to compose the STARTING-SICH (systolic blood pressure, age, onset-to-treatment time for thrombolysis, National Institutes of Health Stroke Scale score, glucose, aspirin alone, aspirin plus clopidogrel, anticoagulant with INR ≤1.7, current infarction sign, hyperdense artery sign) nomogram. The area under the receiver-operating characteristic curve of STARTING-SICH was 0.739. Calibration was good ( P =0.327 for the Hosmer-Lemeshow test). The STARTING-SICH is the first nomogram developed and validated in a large SITS-ISTR cohort for individualized prediction of sICH in intravenous thrombolysis-treated stroke patients. © 2018 American Heart Association, Inc.

What is the value of conducting a trial of r-tPA for the treatment of mild stroke patients?

PubMed

Guzauskas, Gregory F; Chen, Er; Lalla, Deepa; Yu, Elaine; Tayama, Darren; Veenstra, David L

2017-02-01

Background The Phase IIIb, Double-Blind, Multicenter Study to Evaluate the Efficacy and Safety of Alteplase in Patients With Mild Stroke: Rapidly Improving Symptoms and Minor Neurologic Deficits (PRISMS) trial will assess r-tPA in ischemic stroke patients who present with mild deficits (i.e. mild stroke). Aims To assess PRISMS's societal value in clarifying the optimal care for patients with mild ischemic stroke. Methods A value of information (VOI) decision model was developed to compare the outcomes of mild stroke patients treated vs. not treated with r-tPA. Model inputs were derived from a subset of Third International Stroke Trial patients, a recent meta-analysis of r-tPA trials, expert opinion, and other published sources. VOI analyses were also used to assess the expected US societal value of the PRISMS trial and the expected value of reducing uncertainty in key trial estimates. Results The expected net societal value of the PRISMS trial was approximately $210 million ($160 m-$260 m), representing a six-fold return on investment. The value of reducing uncertainty in r-tPA efficacy was approximately $150 million ($100 m-$200 m), while reducing uncertainty in r-tPA safety (increased risk for symptomatic intracranial hemorrhage) did not add additional value in comparison. Conclusions Developing a better understanding of the outcomes of r-tPA treatment in patients with mild ischemic stroke will provide tremendous societal value by clarifying current uncertainty around treatment effectiveness. Enrollment in the PRISMS trial for patients presenting with mild ischemic stroke within 0-3 h of symptom onset should be highly encouraged.

Prevalence and predictors of 6-month fatigue in patients with ischemic stroke: a population-based stroke incidence study in Auckland, New Zealand, 2002-2003.

PubMed

Feigin, Valery L; Barker-Collo, Suzanne; Parag, Varsha; Hackett, Maree L; Kerse, Ngaire; Barber, P Alan; Theadom, Alice; Krishnamurthi, Rita

2012-10-01

Although persistent and significant fatigue affects the daily life of stroke survivors, there are no population-based studies examining the prevalence of fatigue in 6-month survivors of ischemic stroke and few studies of predictors of poststroke fatigue. This article examined data from the Auckland Regional Community Stroke study conducted in Auckland, New Zealand, in 2002 to 2003. Presence of fatigue was evaluated at 6 months in 613 patients with ischemic stroke using a Short Form 36 Vitality Score (energy and fatigue) of ≤ 47. Multivariate logistic regression analysis was used to determine predictors of fatigue development 6 months poststroke. The prevalence of fatigue was 30% (28% in men and 33% in women). There was a clear association between increased prevalence of fatigue and advancing age. The only baseline variables independently associated with an increased risk of developing fatigue at 6 months poststroke were prestroke incontinence and being of New Zealand European ethnicity. Being independent and living alone at baseline were associated with significant reduction in the risk of being fatigued at 6 months poststroke. Severe depression at 6 months was significantly and independently associated with being fatigued. The prevalence of fatigue found in our study is at the lower level of range reported in other studies. The prevalence of fatigue increased with advancing age, as found in most previous studies. Because fatigue can have a negative impact on stroke recovery, particular attention needs to be paid to those who are older, incontinent before stroke, and those who report severe symptoms of depression at 6 months after stroke.

Automated data capture from free-text radiology reports to enhance accuracy of hospital inpatient stroke codes.

PubMed

Flynn, Robert W V; Macdonald, Thomas M; Schembri, Nicola; Murray, Gordon D; Doney, Alexander S F

2010-08-01

Much potentially useful clinical information for pharmacoepidemiological research is contained in unstructured free-text documents and is not readily available for analysis. Routine health data such as Scottish Morbidity Records (SMR01) frequently use generic 'stroke' codes. Free-text Computerised Radiology Information System (CRIS) reports have potential to provide this missing detail. We aimed to increase the number of stroke-type-specific diagnoses by augmenting SMR01 with data derived from CRIS reports and to assess the accuracy of this methodology. SMR01 codes describing first-ever-stroke admissions in Tayside, Scotland from 1994 to 2005 were linked to CRIS CT-brain scan reports occurring with 14 days of admission. Software was developed to parse the text and elicit details of stroke type using keyword matching. An algorithm was iteratively developed to differentiate intracerebral haemorrhage (ICH) from ischaemic stroke (IS) against a training set of reports with pathophysiologically precise SMR01 codes. This algorithm was then applied to CRIS reports associated with generic SMR01 codes. To establish the accuracy of the algorithm a sample of 150 ICH and 150 IS reports were independently classified by a stroke physician. There were 8419 SMR01 coded first-ever strokes. The proportion of patients with pathophysiologically clear diagnoses doubled from 2745 (32.6%) to 5614 (66.7%). The positive predictive value was 94.7% (95%CI 89.8-97.3) for IS and 76.7% (95%CI 69.3-82.7) for haemorrhagic stroke. A free-text processing approach was acceptably accurate at identifying IS, but not ICH. This approach could be adapted to other studies where radiology reports may be informative. 2010 John Wiley & Sons, Ltd.

Combined functional electrical stimulation (FES) and robotic system for wrist rehabiliation after stroke.

PubMed

Hu, Xiaoling; Tong, K Y; Li, R; Chen, M; Xue, J J; Ho, S K; Chen, P N

2010-01-01

Functional electrical stimulation (FES) and rehabilitation robots are techniques used to assist in post-stroke rehabilitation. However, FES and rehabilitation robots are still separate systems currently; and their combined training effects on persons after experiencing a stroke have not been well studied yet. In this work, a new combined FES-robot system driven by user's voluntary intention was developed for wrist joint training after stroke. The performance of the FES-robot assisted wrist tracking was evaluated on five subjects with chronic stroke. With simultaneous assistance from both the FES and robot parts of the system, the motion accuracy was improved and excessive activation in elbow flexor was reduced during wrist tracking.

Optimizing Language for Stroke Motor Rehabilitation: Recommendations from the ACRM Stroke Movement Interventions Subcommittee

PubMed Central

Page, Stephen J.; Schmid, Arlene; Harris, Jocelyn

2012-01-01

As knowledge and interest in stroke motor rehabilitation continue to increase, consistent terminologies that are specific to this discipline must be established. Such language is critical to effective rehabilitative team communication, and is important to facilitating communication among the diverse groups interested in the science and practice of stroke motor rehabilitation. The purpose of this paper is to provide operational definitions for three concepts that are common - and commonly mislabeled - attributes of stroke motor rehabilitation interventions: intensity, duration, and frequency. In developing these guidelines, conceptual frameworks used in the pharmaceutical, exercise, and rehabilitative therapy realms were used. Implications of these definitions for research and clinical practice are also discussed. PMID:22446292

Current and future bioanalytical approaches for stroke assessment.

PubMed

Pullagurla, Swathi R; Baird, Alison E; Adamski, Mateusz G; Soper, Steven A

2015-01-01

Efforts are underway to develop novel platforms for stroke diagnosis to meet the criteria for effective treatment within the narrow time window mandated by the FDA-approved therapeutic (<3 h). Blood-based biomarkers could be used for rapid stroke diagnosis and coupled with new analytical tools, could serve as an attractive platform for managing stroke-related diseases. In this review, we will discuss the physiological processes associated with stroke and current diagnostic tools as well as their associated shortcomings. We will then review information on blood-based biomarkers and various detection technologies. In particular, point of care testing that permits small blood volumes required for the analysis and rapid turn-around time measurements of multiple markers will be presented.

Scottish Stroke Research Network: the first three years.

PubMed

McCormick, K; Langhorne, P; Graham, F E J; McFarlane, C

2010-08-01

Research networks were introduced in the UK to facilitate and improve clinical research and stroke was seen as a priority topic for local research network development. The Scottish Stroke Research Network (SSRN) is one of 11 stroke research networks in the UK. In this article we review the progress of the Scottish Stroke Research Network in the three years since inception. Between 2006-2009 the number of active hospital research sites has increased from 10 to 22 expanding to involve 20 stroke research nurses. There was a corresponding 58% increase in recruitment of participants into stroke studies, from 376 in 2006/07 to 594 in 2008/09. The majority (17/20) of our current studies are interventional. Data from one of these, the CLOTs trial (Clots in Legs Or sTocking after Stroke), demonstrates that the annual recruitment in Scotland increased from a median of 94 (range 6-122) patients per year in the six years before the SSRN, to 140 (135-158) patients per year after SSRN involvement. We currently screen about 50% of Scottish stroke patients and approximately 5% of Scottish stroke patients are participating in research studies that we support. The SSRN has made good progress in the first three years. Increasing the recruitment of screened patients remains a challenge.

A blueprint for transforming stroke rehabilitation care in Canada: the case for change.

PubMed

Teasell, Robert W; Foley, Norine C; Salter, Katherine L; Jutai, Jeffrey W

2008-03-01

Stroke is a major source of disability in Canada and other developed countries, which carries with it a high toll in terms of personal suffering for the stroke survivor and their family in addition to the associated economic costs. Despite the impressive body of evidence describing effective and feasible stroke rehabilitation practices, stroke survivors, their families, and health professionals currently do not benefit from a rehabilitation system that is well organized and evidence based. Using the principles of best evidence, we make the case for needed changes to the current system based on 5 processes of care known to be important in the pursuit of optimal outcomes: (1) admission to specialized stroke rehabilitation units, (2) early admission to stroke rehabilitation units, (3) intensive stroke rehabilitation therapies, (4) task-specific rehabilitation therapies, and (5) well-resourced outpatient programs. Implementation of these strategies will be expected to result in improved functional gain, fewer complications, decreased mortality, and reduced need for institutionalization. In addition to providing improved care for both the stroke survivor and their family, evidence-based stroke rehabilitation care is more efficient and may reduce costs. Our experience in Canada suggests that instituting these 5 measures alone will result in significant improvements to the health care system.

Stroke epidemiology in Karabük city Turkey: Community based study.

PubMed

Padir Şensöz, Nilay; Türk Börü, Ülkü; Bölük, Cem; Bilgiç, Adnan; Öztop Çakmak, Özgür; Duman, Arda; Taşdemir, Mustafa

2018-03-01

Stroke has been projected to increase in developing countries like Turkey. Information about the prevalence of stroke may uncover the etiology of stroke and overcome its impact burden. However, data is limited due to a lack of studies based in Turkey and neighboring regions. We aimed to investigate the prevalence and risk factors of stroke in the Turkish city of Karabük and to pave the way for future epidemiological studies in Turkey. The study was designed as a cross-sectional, door-to-door survey. The questionnaire was completed by a trained team in the presence of the participants according to their answers. Patients who had been diagnosed with stroke prior to the survey were re-examined by a neurologist. 3131 persons who were above 44 years old were screened. 129 of them were found to have had a stroke previously. The prevalence rate of stroke above 44 years was found to be 4.12% (98% confidence level and ± 2% margin of error). 72.1% of stroke patients had hypertension. Male/female ratio was 0.72. This study showed a high prevalence rate of stroke in Karabük Turkey with a low male/female ratio when compared to other studies.

A systematic review of perceived barriers and motivators to physical activity after stroke.

PubMed

Nicholson, Sarah; Sniehotta, Falko F; van Wijck, Frederike; Greig, Carolyn A; Johnston, Marie; McMurdo, Marion E T; Dennis, Martin; Mead, Gillian E

2013-07-01

Physical fitness is impaired after stroke, may contribute to disability, yet is amenable to improvement through regular physical activity. To facilitate uptake and maintenance of physical activity, it is essential to understand stroke survivors' perceived barriers and motivators. Therefore, we undertook a systematic review of perceived barriers and motivators to physical activity after stroke. Electronic searches of EMBASE, Medline, CINAHL, and PsychInfo were performed. We included peer-reviewed journal articles, in English, between 1 January 1966 and 30 August 2010 reporting stroke survivors' perceived barriers and motivators to physical activity. Searches identified 73,807 citations of which 57 full articles were retrieved. Six articles were included, providing data on 174 stroke survivors (range 10 to 83 per article). Two reported barriers and motivators, two reported only motivators, and two reported only barriers. Five were qualitative articles and one was quantitative. The most commonly reported barriers were lack of motivation, environmental factors (e.g. transport), health concerns, and stroke impairments. The most commonly reported motivators were social support and the need to be able to perform daily tasks. This review has furthered our understanding of the perceived barriers and motivators to physical activity after a stroke. This review will enable the development of tailored interventions to target barriers, while building upon perceived motivators to increase and maintain stroke survivors' physical activity. © 2012 The Authors. International Journal of Stroke © 2012 World Stroke Organization.

Increased Risk of Stroke in Patients of Concussion: A Nationwide Cohort Study.

PubMed

Liu, Shih-Wei; Huang, Liang-Chung; Chung, Wu-Fu; Chang, Hsuan-Kan; Wu, Jau-Ching; Chen, Li-Fu; Chen, Yu-Chun; Huang, Wen-Cheng; Cheng, Henrich; Lo, Su-Shun

2017-02-25

Long-term morbidities can develop after traumatic brain injury (TBI). Some studies have suggested that the risk of stroke is higher after TBI, but the association between concussion and stroke remains unclear. Using a national cohort, the authors analyzed the incidence of both hemorrhagic and ischemic strokes in patients with previous concussion. A representative cohort of approximately one million people was followed up for four years. Patients with new-onset concussion were identified ( n = 13,652) as the concussion group. Subsequently, the incidence rates of later stroke events in the concussion group were compared to a sex-, age- and propensity score-matched comparison group ( n = 13,652). The overall incidence rate of stroke in the concussion group was higher than that of the comparison group (9.63 versus 6.52 per 1000 person-years, p < 0.001). Significantly higher stroke risk was observed in the concussion group than in the comparison group (crude hazard ratio 1.48, p < 0.001; adjusted HR 1.65, p < 0.001). In the concussion group, the cumulative incidence rates of both ischemic stroke and hemorrhagic stroke were higher than those of the comparison group (8.9% vs. 5.8% and 2.7% vs. 1.6%, respectively, both p < 0.001). Concussion is an independent risk factor for both ischemic and hemorrhagic strokes. Prevention and monitoring strategies of stroke are therefore suggested for patients who have experienced concussion.

Angiogenesis-regulating microRNAs and ischemic stroke

PubMed Central

Yin, Ke-Jie; Hamblin, Milton; Chen, Y. Eugene

2014-01-01

Stroke is a leading cause of death and disability worldwide. Ischemic stroke is the dominant subtype of stroke and results from focal cerebral ischemia due to occlusion of major cerebral arteries. Thus, the restoration or improvement of reduced regional cerebral blood supply in a timely manner is very critical for improving stroke outcomes and post-stroke functional recovery. The recovery from ischemic stroke largely relies on appropriate restoration of blood flow via angiogenesis. Newly formed vessels would allow increased cerebral blood flow, thus increasing the amount of oxygen and nutrients delivered to affected brain tissue. Angiogenesis is strictly controlled by many key angiogenic factors in the central nervous system, and these molecules have been well-documented to play an important role in the development of angiogenesis in response to various pathological conditions. Promoting angiogenesis via various approaches that target angiogenic factors appears to be a useful treatment for experimental ischemic stroke. Most recently, microRNAs (miRs) have been identified as negative regulators of gene expression in a post-transcriptional manner. Accumulating studies have demonstrated that miRs are essential determinants of vascular endothelial cell biology/angiogenesis as well as contributors to stroke pathogenesis. In this review, we summarize the knowledge of stroke-associated angiogenic modulators, as well as the role and molecular mechanisms of stroke-associated miRs with a focus on angiogenesis-regulating miRs. Moreover, we further discuss their potential impact on miR-based therapeutics in stroke through targeting and enhancing post-ischemic angiogenesis. PMID:26156265

New Approach to Identify Ischemic Stroke Patients at Risk to Develop Hemorrhagic Transformation

PubMed Central

MANOLESCU, Bogdan Nicolae; JICKLING, Glen C.

2012-01-01

ABSTRACT Some patients with ischemic stroke are subject to hemorrhagic transformation, a complication leading to increased patient morbidity and mortality. The discovery of biomarkers that can be used to identify ischemic strokes prone to this complication are very important for the clinical practice because therapy could be altered to mitigate the risk. We discuss here the results of a trial that evaluated for the first time tight junction proteins as biomarkers of blood-brain barrier disruption and hemorrhagic transformation in ischemic stroke. PMID:23482691

Neurochemical changes underpinning the development of adjunct therapies in recovery after stroke: A role for GABA?

PubMed

Johnstone, Ainslie; Levenstein, Jacob M; Hinson, Emily L; Stagg, Charlotte J

2017-01-01

Stroke is a leading cause of long-term disability, with around three-quarters of stroke survivors experiencing motor problems. Intensive physiotherapy is currently the most effective treatment for post-stroke motor deficits, but much recent research has been targeted at increasing the effects of the intervention by pairing it with a wide variety of adjunct therapies, all of which aim to increase cortical plasticity, and thereby hope to maximize functional outcome. Here, we review the literature describing neurochemical changes underlying plasticity induction following stroke. We discuss methods of assessing neurochemicals in humans, and how these measurements change post-stroke. Motor learning in healthy individuals has been suggested as a model for stroke plasticity, and we discuss the support for this model, and what evidence it provides for neurochemical changes. One converging hypothesis from animal, healthy and stroke studies is the importance of the regulation of the inhibitory neurotransmitter GABA for the induction of cortical plasticity. We discuss the evidence supporting this hypothesis, before finally summarizing the literature surrounding the use of adjunct therapies such as non-invasive brain stimulation and SSRIs in post-stroke motor recovery, both of which have been show to influence the GABAergic system.

Income Inequality, Economic Growth and Stroke Mortality in Brazil: Longitudinal and Regional Analysis 2002-2009.

PubMed

Vincens, Natalia; Stafström, Martin

2015-01-01

Stroke accounts for more than 10% of all deaths globally and most of it occurs in low- and middle-income countries (LMIC). Income inequality and gross domestic product (GDP) per capita has been associated to stroke mortality in developed countries. In LMIC, GDP per capita is considered to be a more relevant health determinant than income inequality. This study aims to investigate if income inequality is associated to stroke mortality in Brazil at large, but also on regional and state levels, and whether GDP per capita modulates the impact of this association. Stroke mortality rates, Gini index and GDP per capita data were pooled for the 2002 to 2009 period from public available databases. Random effects models were fitted, controlling for GDP per capita and other covariates. Income inequality was independently associated to stroke mortality rates, even after controlling for GDP per capita and other covariates. GDP per capita reduced only partially the impact of income inequality on stroke mortality. A decrease in 10 points in the Gini index was associated with 18% decrease in the stroke mortality rate in Brazil. Income inequality was independently associated to stroke mortality in Brazil.

Design of a Family Study Among High-Risk Caribbean Hispanics: The Northern Manhattan Family Study

PubMed Central

Sacco, Ralph L.; Sabala, Edison A.; Rundek, Tanja; Juo, Suh-Hang Hank; Huang, Jinaping Sam; DiTullio, Marco; Homma, Shunichi; Almonte, Katihurka; Lithgow, Carlos García; Boden-Albala, Bernadette

2008-01-01

Stroke continues to kill disproportionately more Blacks and Hispanics than Whites in the United States. Racial/ethnic variations in the incidence of stroke and prevalence of stroke risk factors are probably explained by both genetic and environmental influences. Family studies can help identify genetic predisposition to stroke and potential stroke precursors. Few studies have evaluated the heritability of these stroke risk factors among non-White populations, and none have focused on Caribbean Hispanic populations. The aim of the Northern Manhattan Family Study (NOMAFS) is to investigate the gene-environment interaction of stroke risk factors among Caribbean Hispanics. The unique recruitment and methodologic approaches used in this study are relevant to the design and conduct of genetic aggregation studies to investigate complex genetic disorders in non-White populations. The aim of this paper is to describe the NOMAFS and report enrollment and characteristics of the participants. The NO-MAFS will provide a data resource for the exploration of the genetic determinants of highly heritable stroke precursor phenotypes that are less complex than the stroke phenotype. Understanding the gene environment interaction is the critical next step toward the development of new and unique approaches to disease prevention and interventions. PMID:17682370

The development and implementation of the structured training programme for caregivers of inpatients after stroke (TRACS) intervention: the London Stroke Carers Training Course.

PubMed

Forster, Anne; Dickerson, Josie; Melbourn, Anne; Steadman, Jayne; Wittink, Margreet; Young, John; Kalra, Lalit; Farrin, Amanda

2015-03-01

To describe the content and delivery of the adapted London Stroke Carers Training Course intervention evaluated in the Training Caregivers after Stroke (TRACS) trial. The London Stroke Carers Training Course is a structured training programme for caregivers of inpatients who are likely to return home after their stroke. The course was delivered by members of the multidisciplinary team while the patient was in the stroke unit with one recommended 'follow through' session after discharge home. The intervention consists of 14 training components (six mandatory) that were identified as important knowledge/skills that caregivers would need to be able to care for the stroke patient after discharge home. Following national training days, the London Stroke Carers Training Course was disseminated to intervention sites by the cascade method of implementation. The intervention was adapted for implementation across a range of stroke units. Training days were well attended (median 2.5 and 2.0 attendees per centre for the first and second days, respectively) and the feedback positive, demonstrating 'face validity' for the intervention. However cascading of this training to other members of the multidisciplinary team was not consistent, with 7/18 centres recording no cascade training. The adapted London Stroke Carers Training Course provided a training programme that could be delivered in a standardised, structured way in a variety of stroke unit settings throughout the UK. The intervention was well received by stroke unit staff, however, the cascade method of implementation was not as effective as we would have wished. © The Author(s) 2014.

Determinants of Health-Related Quality of Life in Taiwanese Middle-Aged Women Stroke Survivors.

PubMed

Pai, Hsiang-Chu; Wu, Ming-Hsiu; Chang, Mei-Yueh

Female stroke victims have a higher survival rate and experience a greater loss of quality of life than do male stroke victims. The aim of this study was to evaluate the determinants of health-related quality of life in middle-aged women stroke survivors. This study is a cross-sectional design. This cross-sectional research uses a descriptive, prospective, and correlational study design to investigate the associations between latent variables. Participants included women stroke survivors, aged 45-65 years, who were patients at a medical center in Taiwan. Participants completed an interview and a six-part questionnaire comprising the Short-Form Health Survey (SF-36), National Institutes of Health Stroke Scale, Modified Rankin Scale, Burden Scale, Chinese Health Questionnaire, and five items that pertain to the survivor's cognitive appraisal of coping. Structural equation modeling (SEM), with the use of the partial least squares (PLS) method, was used to examine the proposed conceptual model. A total of 48 dyad samples (48 female stroke survivors, mean age = 55.29; 48 caregivers, mean age = 42.71) participated in the study. Overall, women's physical functioning (PF; stroke severity), cognitive appraisal of coping, and caregiver's psychosocial functioning were the predictors, explaining 43.3% of the variance in women's health-related quality of life. We found that female stroke survivors' level of stroke severity and negative appraisal-impact of stroke are significant predictors of the stroke survivor's quality of life. In addition to assisting women in their PF rehabilitation, rehabilitation nurses also should help to develop survivors' self-care confidence as a means to avoid the recurrence of stroke.

Development, Validation, and Assessment of an Ischemic Stroke or Transient Ischemic Attack-Specific Prediction Tool for Obstructive Sleep Apnea.

PubMed

Sico, Jason J; Yaggi, H Klar; Ofner, Susan; Concato, John; Austin, Charles; Ferguson, Jared; Qin, Li; Tobias, Lauren; Taylor, Stanley; Vaz Fragoso, Carlos A; McLain, Vincent; Williams, Linda S; Bravata, Dawn M

2017-08-01

Screening instruments for obstructive sleep apnea (OSA), as used routinely to guide clinicians regarding patient referral for polysomnography (PSG), rely heavily on symptomatology. We sought to develop and validate a cerebrovascular disease-specific OSA prediction model less reliant on symptomatology, and to compare its performance with commonly used screening instruments within a population with ischemic stroke or transient ischemic attack (TIA). Using data on demographic factors, anthropometric measurements, medical history, stroke severity, sleep questionnaires, and PSG from 2 independently derived, multisite, randomized trials that enrolled patients with stroke or TIA, we developed and validated a model to predict the presence of OSA (i.e., Apnea-Hypopnea Index ≥5 events per hour). Model performance was compared with that of the Berlin Questionnaire, Epworth Sleepiness Scale (ESS), the Snoring, Tiredness, Observed apnea, high blood Pressure, Body mass index, Age, Neck circumference, and Gender instrument, and the Sleep Apnea Clinical Score. The new SLEEP Inventory (Sex, Left heart failure, ESS, Enlarged neck, weight [in Pounds], Insulin resistance/diabetes, and National Institutes of Health Stroke Scale) performed modestly better than other instruments in identifying patients with OSA, showing reasonable discrimination in the development (c-statistic .732) and validation (c-statistic .731) study populations, and having the highest negative predictive value of all in struments. Clinicians should be aware of these limitations in OSA screening instruments when making decisions about referral for PSG. The high negative predictive value of the SLEEP INventory may be useful in determining and prioritizing patients with stroke or TIA least in need of overnight PSG. Published by Elsevier Inc.

[Contribution of Professor SHI Xue-min's academic thoughts to treatment of stroke].

PubMed

Liu, Jian; Fan, Xiao-Nong; Wang, Shu

2014-01-01

Based on the thought of Zhishen (a kind of mind regulation), Professor SHI Xue-min, academician of the China Academy of Engineering, found the Xingnao Kaiqiao (to refresh the mind and to cause resuscitation) acupuncture method, which still plays an important role in the acupuncture treatment of wind stroke nowadays. Meanwhile, great importance is attached to the comprehensive treatment of wind stroke. Danqi Piantan capsule (see text) is developed and "wind stroke unit" is set up. In recent years, Professor SHI shifts the center of research to the treatment of hypertension, the risk factor of wind stroke. Taking Renying (ST 9) as the major acupoint, acupuncture with standard measurement and manipulations is established. And good clinical effect has been obtained as well. Therefore, this article focuses on the introduction of Professor SHI Xue-min's contribution to wind stroke treatment.

Influence of Inflammation on Poststroke Plasticity

PubMed Central

Kossut, Malgorzata

2013-01-01

Age-related brain injuries including stroke are a leading cause of morbidity and mental disability worldwide. Most patients who survive stroke experience some degree of recovery. The restoration of lost functions can be explained by neuronal plasticity, understood as brain ability to reorganize and remodel itself in response to changed environmental requirements. However, stroke triggers a cascade of events which may prevent the normal development of the plastic changes. One of them may be inflammatory response initiated immediately after stroke, which has been found to contribute to neuronal injury. Some recent evidence though has suggested that inflammatory reaction can be also neuroprotective. This paper attempts to discuss the influence of poststroke inflammatory response on brain plasticity and stroke outcome. We also describe the recent anti-inflammatory strategies that have been effective for recovery in experimental stroke. PMID:23533818

Kids Identifying and Defeating Stroke (KIDS): Development and Implementation of a Multi-Ethnic Health Education Intervention to Increase Stroke Awareness Among Middle School Students and Their Parents

PubMed Central

Conley, Kathleen M; Majersik, Jennifer; Gonzales, Nicole R; Maddox, Katherine E; Pary, Jennifer K; Brown, Devin L; Moyé, Lemuel A; Espinosa, Nina; Grotta, James C; Morgenstern, Lewis B

2009-01-01

The KIDS (Kids Identifying and Defeating Stroke) Program is a three-year prospective, randomized, controlled, multiethnic school-based intervention study. Program goals include increasing knowledge of stroke signs and treatment and intention to immediately call 911 among Mexican American (MA) and non-Hispanic white (NHW) middle school students and their parents. This article describes the design, implementation and interim evaluation of this theory-based intervention. Intervention students received a culturally appropriate stroke education program divided into four 50-minute classes each year during the 6th, 7th, and 8th grades. Each class session also included a homework assignment that involved the students’ parents or other adult partners. Interim-test results indicate that this educational intervention was successful in improving students’ stroke symptom and treatment knowledge and intent to call 911 upon witnessing a stroke compared with controls (p<0.001). We conclude that this school-based educational intervention to reduce delay time to hospital arrival for stroke shows early promise. PMID:18332150

What do nurses and therapists think about the positioning of stroke patients?

PubMed

Rowat, A M

2001-06-01

At present, there are a number of different positioning strategies for stroke patients, but these are mainly based on clinical experience rather than research. Prior to developing a study to evaluate the effect of positioning on outcome after stroke, it was important to establish if nurses in our hospital had given much thought to the positioning of stroke patients. This study aimed to explore whether nurses working on the stroke unit at a Scottish teaching hospital held different views on the positioning of conscious and unconscious stroke patients to nurses working on other wards with stroke patients and therapists. Questionnaires on various aspects of patient positioning were sent to 150 nurses and 25 therapists working in five specialities where stroke patients are cared for in a large teaching hospital. Overall, the majority of nurses and therapists (74%) believed that the best position for conscious stroke patients was sitting in a chair. Also, 80% of them believed that the best position for unconscious stroke patients was lying on the nonparetic side. There was less of a consensus between nurses and therapists working in the five specialities as to whether it was appropriate for conscious or unconscious stroke patients to lie on their paretic side, lie supine or sit propped-up in bed in either a 30 or 70 degrees angle. The lack of consensus between nurses working in the five specialities is probably because at present there is little research to guide nursing practices for the positioning of stroke patients. Therefore, research to confirm which positions improves or hinders outcome after stroke is essential. Indeed, positioning is a simple inexpensive strategy, which could have a substantial public health impact, as stroke is so common.