Striking Distance Determined From High-Speed Videos and Measured Currents in Negative Cloud-to-Ground Lightning

NASA Astrophysics Data System (ADS)

Visacro, Silverio; Guimaraes, Miguel; Murta Vale, Maria Helena

2017-12-01

First and subsequent return strokes' striking distances (SDs) were determined for negative cloud-to-ground flashes from high-speed videos exhibiting the development of positive and negative leaders and the pre-return stroke phase of currents measured along a short tower. In order to improve the results, a new criterion was used for the initiation and propagation of the sustained upward connecting leader, consisting of a 4 A continuous current threshold. An advanced approach developed from the combined use of this criterion and a reverse propagation procedure, which considers the calculated propagation speeds of the leaders, was applied and revealed that SDs determined solely from the first video frame showing the upward leader can be significantly underestimated. An original approach was proposed for a rough estimate of first strokes' SD using solely records of current. This approach combines the 4 A criterion and a representative composite three-dimensional propagation speed of 0.34 × 106 m/s for the leaders in the last 300 m propagated distance. SDs determined under this approach showed to be consistent with those of the advanced procedure. This approach was applied to determine the SD of 17 first return strokes of negative flashes measured at MCS, covering a wide peak-current range, from 18 to 153 kA. The estimated SDs exhibit very high dispersion and reveal great differences in relation to the SDs estimated for subsequent return strokes and strokes in triggered lightning.

Comparison of fast electric field changes from subsequent return strokes of natural and triggered lightning

NASA Technical Reports Server (NTRS)

Le Vine, D. M.; Willett, J. C.; Bailey, J. C.

1989-01-01

Fast electric field changes from subsequent return strokes of natural and triggered lightning with propagation paths almost entirely over water are compared. Data were collected at the Kennedy Space Center, Florida, during the summer of 1987. Comparisons have been made of the average shape, the risetime, and the spectrum of the electric field changes. To a first approximation, the waveforms are very similar; however, the electric field changes from the triggered flashes tend to rise to peak faster and decay faster than do their counterparts in natural cloud-to-ground flashes.

Update Direct-Strike Lightning Environment for Stockpile-to-Target Sequence (Second Revision)

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

Uman, Martin A.; Rakov, V. A.; Elisme, J. O.

2010-10-05

The University of Florida has surveyed all relevant publications reporting lightning characteristics and presents here an up-to-date version of the direct-strike lightning environment specifications for nuclear weapons published in 1989 by R. J. Fisher and M. A. Uman. Further, we present functional expressions for current vs. time, current derivative vs. time, second current derivative vs. time, charge transfer vs. time, and action integral (specific energy) vs. time for positive and negative first return strokes, for negative subsequent return strokes, and for positive and negative continuing currents; and we give sets of constants for these functional expressions so that the resultantmore » waveforms exhibit approximately the median and extreme lightning parameters presented in the updated direct strike environment. Fourier transforms of the return stroke current waveforms are presented. The results of our literature survey are included in three Appendices entitled Return Stroke Current, Continuing Current, and Positive Lightning.« less

Characteristics of lightning leader propagation and ground attachment

NASA Astrophysics Data System (ADS)

Jiang, Rubin; Qie, Xiushu; Wang, Zhichao; Zhang, Hongbo; Lu, Gaopeng; Sun, Zhuling; Liu, Mingyuan; Li, Xun

2015-12-01

The grounding process and the associated leader behavior were analyzed by using high-speed video record and time-correlated electric field change for 37 natural negative cloud-to-ground flashes. Weak luminous grounded channel was recognized below the downward leader tip in the frame preceding the return stroke, which is inferred as upward connecting leader considering the physical process of lightning attachment, though not directly confirmed by sequential frames. For stepped leader-first return strokes, the upward connecting leaders tend to be induced by those downward leader branches with brighter luminosity and lower channel tip above ground, and they may accomplish the attachment with great possibility. The upward connecting leaders for 2 out of 61 leader-subsequent stroke sequences were captured in the frame prior to the return stroke, exhibiting relatively long channel lengths of 340 m and 105 m, respectively. The inducing downward subsequent leaders were of the chaotic type characterized by irregular electric field pulse train with duration of 0.2-0.3 ms. The transient drop of the high potential difference between stepped leader system and ground when the attachment occurred would macroscopically terminate the propagation of those ungrounded branches while would not effectively prevent the development of the existing space stem systems in the low-conductivity streamer zone apart from the leader tip. When the ungrounded branches are of poor connection with the main stroke channel, their further propagation toward ground would be feasible. These two factors may contribute to the occurrence of multiple grounding within the same leader-return stroke sequence.

Interaction of Lightning Electromagnetic Pulse with the Ionosphere as Inferred from Wideband Measurements and Modeling

NASA Astrophysics Data System (ADS)

Somu, Vijaya Bhaskar

Apparent ionospheric reflection heights estimated using the zero-to-zero and peak-to-peak methods to measure skywave delay relative to the groundwave were compared for 108 first and 124 subsequent strokes observed at LOG in 2009. For either metric there was a considerable decrease in average re ection height for subsequent strokes relative to first strokes. Median uncertainties in daytime re ection heights did not exceed 0.7 km. The standard errors in mean re ection heights were less than 3% of the mean value. Apparent changes in re ection height (estimated using the peak-to-peak method) within individual ashes for 54 daytime and 11 nighttime events at distances ranging from 50 km to 330 km were compared. For daytime conditions, the majority of the ashes showed a monotonic decrease in re ection height. For nighttime ashes, the monotonic decrease was found to be considerably less frequent. The apparent ionospheric re ection height tends to increase with return-stroke peak current. In order to increase the sample size for nighttime conditions, additional data for 43 nighttime flashes observed at LOG in 2014 were analyzed. The "fast-break-point" method of measuring skywave delay (McDonald et al., 1979) was additionally used. The 2014 results for return strokes are generally consistent with the 2009 results. The 2014 data were also used for estimating ionospheric re ection heights for elevated sources (6 CIDs and 3 PB pulses) using the double-skywave feature. The results were compared with re ection heights estimated for corresponding return strokes (if any), and fairly good agreement was generally found. It has been shown, using two different FDTD simulation codes, that the observed differences in re ection height cannot be explained by the difference in the frequency content of first and subsequent return-stroke currents. FDTD simulations showed that within 200 km the re ection heights estimated using the peak-to-peak method are close to the hOE parameter of the ionospheric profile for both daytime and nighttime conditions and for both first and second skywaves. The TL model was used to estimate the radial extent of elves produced by the interaction of LEMP with the ionosphere as a function of return-stroke peak current. For a peak current of 100 kA and the speed equal to one-half of the speed of light, the expected radius of elves is 157 km. Skywaves associated with 24 return strokes in 6 lightning ashes triggered at CB in 2015 and recorded at LOG (at a distance of 45 km from CB) were not found for any of the strokes recorded. In contrast, natural-lightning strokes do produce skywaves at comparable distances. One possible reason is the difference in the higher-frequency content (field waveforms for triggered lightning are more narrow than for natural lightning).

Statistical analysis of electric field parameters for negative lightning in Malaysia

NASA Astrophysics Data System (ADS)

Wooi, Chin-Leong; Abdul-Malek, Zulkurnain; Ahmad, Noor-Azlinda; El Gayar, Ali I.

2016-08-01

This paper presents a comparative study on the electric field and its derivative parameters of negative lightning in Malaysia and other regions. This study is the first in Malaysia where the parameters of negative electric field and its derivative are thoroughly analyzed. 104 negative lightning flashes containing 277 negative return strokes occurring within 10-100 km from the measuring station and recorded during monsoon period in the state of Johor, Malaysia had been analyzed. It was found that 73% of the recorded flashes are multiple strokes with an average multiplicity of 2.6 strokes per flash. For first return strokes, the arithmetic mean (AM) of initial peak electric field and the AM of initial peak electric field derivative are 21.8 V/m and 11.3 V/m/μs, respectively. The initial peaks of electric field and its derivative for first return strokes are larger than those for the subsequent return strokes. Comparison of overall results with those obtained earlier in Sri Lanka, Germany, Sweden, Japan, Florida indicates that several electric field and its derivative parameters are affected by propagation media and geographical region. Similarity of results with other countries having the same climatic condition is also observed.

The RF spectra of first and subsequent lightning return strokes in the 1- to 200-km range

NASA Technical Reports Server (NTRS)

Serhan, G. I.; Uman, M. A.; Childers, D. G.; Lin, Y. T.

1980-01-01

An experimental characterization of the frequency spectra of first and subsequent stroke electric fields are presented over a distance range from about 1 km, where the fields are primarily electrostatic, to 200 km, where they are primarily radiation. Spectra are presented to about 700 kHz for lightning within 12 km and to about 300 kHz for lightning at 50 and 200 km. It is shown that the return stroke ground wave spectrum beyond 50 km has a peak near 4 kHz but that within 10 km the spectrum shows a steady increase with decreasing frequency to 1 kHz. Frequency spectra at all ranges fall off roughly as 1/f for frequencies between 5 and 100 kHz, while the falloff above 100 kHz is faster as the distance to the stroke increases. From this high-frequency attenuation an RF conductivity for central Florida of between 0.002 and 0.005/ohm/m was determined.

Attachment process in rocket-triggered lightning strokes

NASA Astrophysics Data System (ADS)

Wang, D.; Rakov, V. A.; Uman, M. A.; Takagi, N.; Watanabe, T.; Crawford, D. E.; Rambo, K. J.; Schnetzer, G. H.; Fisher, R. J.; Kawasaki, Z.-I.

1999-01-01

In order to study the lightning attachment process, we have obtained highly resolved (about 100 ns time resolution and about 3.6 m spatial resolution) optical images, electric field measurements, and channel-base current recordings for two dart leader/return-stroke sequences in two lightning flashes triggered using the rocket-and-wire technique at Camp Blanding, Florida. One of these two sequences exhibited an optically discernible upward-propagating discharge that occurred in response to the approaching downward-moving dart leader and connected to this descending leader. This observation provides the first direct evidence of the occurrence of upward connecting discharges in triggered lightning strokes, these strokes being similar to subsequent strokes in natural lightning. The observed upward connecting discharge had a light intensity one order of magnitude lower than its associated downward dart leader, a length of 7-11 m, and a duration of several hundred nanoseconds. The speed of the upward connecting discharge was estimated to be about 2 × 107 m/s, which is comparable to that of the downward dart leader. In both dart leader/return-stroke sequences studied, the return stroke was inferred to start at the point of junction between the downward dart leader and the upward connecting discharge and to propagate in both upward and downward directions. This latter inference provides indirect evidence of the occurrence of upward connecting discharges in both dart leader/return-stroke sequences even though one of these sequences did not have a discernible optical image of such a discharge. The length of the upward connecting discharges (observed in one case and inferred from the height of the return-stroke starting point in the other case) is greater for the event that is characterized by the larger leader electric field change and the higher return-stroke peak current. For the two dart leader/return-stroke sequences studied, the upward connecting discharge lengths are estimated to be 7-11 m and 4-7 m, with the corresponding return-stroke peak currents being 21 kA and 12 kA, and the corresponding leader electric field changes 30 m from the rocket launcher being 56 kV/m and 43 kV/m. Additionally, we note that the downward dart leader light pulse generally exhibits little variation in its 10-90% risetime and peak value over some tens of meters above the return-stroke starting point, while the following return-stroke light pulse shows an appreciable increase in risetime and a decrease in peak value while traversing the same section of the lightning channel. Our findings regarding (1) the initially bidirectional development of return-stroke process and (2) the relatively strong attenuation of the upward moving return-stroke light (and by inference current) pulse over the first some tens of meters of the channel may have important implications for return-stroke modeling.

Lightning Return-Stroke Current Waveforms Aloft, from Measured Field Change, Current, and Channel Geometry

NASA Technical Reports Server (NTRS)

Willett, J. C.; LeVine, D. M.; Idone, V. P.

2006-01-01

Three-dimensional reconstructions of six rocket-triggered lightning channels are derived from stereo photographs. These reconstructed channels are used to infer the behavior of the current in return strokes above the ground from current waveforms measured at the channel base and electric-field-change waveforms measured at a range of 5.2 kilometers for 24 return strokes in these channels. Streak photographs of 14 of the same strokes are analyzed to determine the rise times, propagation speeds, and amplitudes of relative light intensity for comparison with the electrical inferences. Results include the following: 1) The fine structure of the field-change waveforms that were radiated by these subsequent return strokes can be explained, in large part, by channel geometry. 2) The average 10 - 90% rise time of the stroke current increased by about a factor of seven in our sample, from an observed 0.31 plus or minus 0.17 microseconds at the surface to an inferred 2.2 plus or minus 0.5 microcseconds at 1 kilometer path length above the surface. 3) The three-dimensional propagation speed of the current front averaged 1.80 plus or minus 0.24 X 10(exp 8) meters per second over channel lengths typically greater than 1 kilometer. 4) Assuming that the measured current was entirely due to the return stroke forced an unreasonably large and abrupt reduction in inferred current amplitude over the first few tens of meters above the surface, especially in cases when the leader was bright relative to its stroke. Therefore, a significant fraction of the current at the surface was probably due to the leader, at least in such cases. 5) Peak return-stroke currents decreased by approximately 37 plus or minus 12% from 100 meters to 1 kilometer of path length above the surface. Because of uncertainty about how to partition the measured current between leader and return stroke, we are unable to infer the variation of current amplitude near the ground.

An experimental test of the 'transmission-line model' of electromagnetic radiation from triggered lightning return strokes

NASA Technical Reports Server (NTRS)

Willett, J. C.; Idone, V. P.; Orville, R. E.; Leteinturier, C.; Eybert-Berard, A.

1988-01-01

Peak currents, two-dimensional average propagation speeds, and electric field waveforms for a number of subsequent return strikes in rocket-triggered lightning flashes were measured in order to test the 'transmission-line model' of return-stroke radiation of Uman and McLain (1970). Reasonable agreement is found between the propagation speeds measured with the streak camera and those deduced from the transmission-line model. A modification of the model is proposed in which two wave fronts travel upward and downward away from a junction point a short distance above the ground.

An experimental test of the 'transmission-line model' of electromagnetic radiation from triggered lightning return strokes

NASA Astrophysics Data System (ADS)

Willett, J. C.; Idone, V. P.; Orville, R. E.; Leteinturier, C.; Eybert-Berard, A.

1988-04-01

Peak currents, two-dimensional average propagation speeds, and electric field waveforms for a number of subsequent return strikes in rocket-triggered lightning flashes were measured in order to test the 'transmission-line model' of return-stroke radiation of Uman and McLain (1970). Reasonable agreement is found between the propagation speeds measured with the streak camera and those deduced from the transmission-line model. A modification of the model is proposed in which two wave fronts travel upward and downward away from a junction point a short distance above the ground.

Lightning energetics: Estimates of energy dissipation in channels, channel radii, and channel-heating risetimes

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

Borovsky, J.E.

1998-05-01

In this report, several lightning-channel parameters are calculated with the aid of an electrodynamic model of lightning. The electrodynamic model describes dart leaders and return strokes as electromagnetic waves that are guided along conducting lightning channels. According to the model, electrostatic energy is delivered to the channel by a leader, where it is stored around the outside of the channel; subsequently, the return stroke dissipates this locally stored energy. In this report this lightning-energy-flow scenario is developed further. Then the energy dissipated per unit length in lightning channels is calculated, where this quantity is now related to the linear chargemore » density on the channel, not to the cloud-to-ground electrostatic potential difference. Energy conservation is then used to calculate the radii of lightning channels: their initial radii at the onset of return strokes and their final radii after the channels have pressure expanded. Finally, the risetimes for channel heating during return strokes are calculated by defining an energy-storage radius around the channel and by estimating the radial velocity of energy flow toward the channel during a return stroke. In three appendices, values for the linear charge densities on lightning channels are calculated, estimates of the total length of branch channels are obtained, and values for the cloud-to-ground electrostatic potential difference are estimated. {copyright} 1998 American Geophysical Union« less

Psychosocial Outcomes in StrokE: the POISE observational stroke study protocol

PubMed Central

Hackett, Maree L; Glozier, Nick; Jan, Stephen; Lindley, Richard

2009-01-01

Background Each year, approximately 12,000 Australians of working age survive a stroke. As a group, younger stroke survivors have less physical impairment and lower mortality after stroke compared with older survivors; however, the psychosocial and economic consequences are potentially substantial. Most of these younger stroke survivors have responsibility for generating an income or providing family care and indicate that their primary objective is to return to work. However, effective vocational rehabilitation strategies to increase the proportion of younger stroke survivors able to return to work, and information on the key target areas for those strategies, are currently lacking. Methods/Design This multi-centre, three year cohort study will recruit a representative sample of younger (< 65 years) stroke survivors to determine the modifiable predictors of subsequent return to work. Participants will be recruited from the New South Wales Stroke Services (SSNSW) network, the only well established and cohesively operating and managed, network of acute stroke units in Australia. It is based within the Greater Metropolitan area of Sydney including Wollongong and Newcastle, and extends to rural areas including Wagga Wagga. The study registration number is ACTRN12608000459325. Discussion The study is designed to identify targets for rehabilitation-, social- and medical-intervention strategies that promote and maintain healthy ageing in people with cardiovascular and mental health conditions, two of the seven Australian national health priority areas. This will rectify the paucity of information internationally around optimal clinical practice and social policy in this area. PMID:19519918

Update Direct-Strike Lightning Environment for Stockpile-to-Target Sequence

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

Uman, M A; Rakov, V A; Elisme, J O

2008-10-01

The University of Florida has surveyed all relevant publications reporting lightning characteristics and presents here an up-to-date version of the direct-strike lightning environment specifications for nuclear weapons published in 1989 by R. J. Fisher and M. A. Uman. Further, we present functional expressions for current vs. time, current derivative vs. time, second current derivative vs. time, charge transfer vs. time, and action integral (specific energy) vs. time for first return strokes, for subsequent return strokes, and for continuing currents; and we give sets of constants for these expressions so that they yield approximately the median and extreme negative lightning parametersmore » presented in this report. Expressions for the median negative lightning waveforms are plotted. Finally, we provide information on direct-strike lightning damage to metals such as stainless steel, which could be used as components of storage containers for nuclear waste materials; and we describe UF's new experimental research program to add to the sparse data base on the properties of positive lightning. Our literature survey, referred to above, is included in four Appendices. The following four sections (II, III, IV, and V) of this final report deal with related aspects of the research: Section II. Recommended Direct-Strike Median and Extreme Parameters; Section III. Time-Domain Waveforms for First Strokes, Subsequent Strokes, and Continuing Currents; Section IV. Damage to Metal Surfaces by Lightning Currents; and Section V. Measurement of the Characteristics of Positive Lightning. Results of the literature search used to derive the material in Section II and Section IV are found in the Appendices: Appendix 1. Return Stroke Current, Appendix 2. Continuing Current, Appendix 3. Positive Lightning, and Appendix 4. Lightning Damage to Metal Surfaces.« less

Bipolar cloud-to-ground lightning flash observations

NASA Astrophysics Data System (ADS)

Saba, Marcelo M. F.; Schumann, Carina; Warner, Tom A.; Helsdon, John H.; Schulz, Wolfgang; Orville, Richard E.

2013-10-01

lightning is usually defined as a lightning flash where the current waveform exhibits a polarity reversal. There are very few reported cases of cloud-to-ground (CG) bipolar flashes using only one channel in the literature. Reports on this type of bipolar flashes are not common due to the fact that in order to confirm that currents of both polarities follow the same channel to the ground, one necessarily needs video records. This study presents five clear observations of single-channel bipolar CG flashes. High-speed video and electric field measurement observations are used and analyzed. Based on the video images obtained and based on previous observations of positive CG flashes with high-speed cameras, we suggest that positive leader branches which do not participate in the initial return stroke of a positive cloud-to-ground flash later generate recoil leaders whose negative ends, upon reaching the branch point, traverse the return stroke channel path to the ground resulting in a subsequent return stroke of opposite polarity.

Protection characteristics of a Faraday cage compromised by lightning burnthrough.

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

Warne, Larry Kevin; Bystrom, Edward; Jorgenson, Roy Eberhardt

2012-01-01

A lightning flash consists of multiple, high-amplitude but short duration return strokes. Between the return strokes is a lower amplitude, continuing current which flows for longer duration. If the walls of a Faraday cage are made of thin enough metal, the continuing current can melt a hole through the metal in a process called burnthrough. A subsequent return stroke can couple energy through this newly-formed hole. This LDRD is a study of the protection provided by a Faraday cage when it has been compromised by burnthrough. We initially repeated some previous experiments and expanded on them in terms of scopemore » and diagnostics to form a knowledge baseline of the coupling phenomena. We then used a combination of experiment, analysis and numerical modeling to study four coupling mechanisms: indirect electric field coupling, indirect magnetic field coupling, conduction through plasma and breakdown through the hole. We discovered voltages higher than those encountered in the previous set of experiments (on the order of several hundreds of volts).« less

Observations of lightning processes using VHF radio interferometry

NASA Technical Reports Server (NTRS)

Rhodes, C. T.; Shao, X. M.; Krehbiel, P. R.; Thomas, R.

1991-01-01

A single station, multiple baseline radio interferometer was used to locate the direction of VHF radiation from lightning discharges with microsec time resolution. Radiation source directions and electric field waveforms were analyzed for various types of breakdown events. These include initial breakdown and K type events of in-cloud activity, and the leaders of initial and subsequent strokes to ground and activity during and following return strokes. Radiation during the initial breakdown of a flash and in the early stages of initial leaders to ground is found to be similar. In both instances, the activity consists of localized bursts of radiation that are intense and slow moving. Motion within a given burst is unresolved by the interferometer. Radiation from in-cloud K type events is essentially the same as that from dart leaders; in both cases it is produced at the leading edge of a fast moving streamer that propagates along a well defined, often extensive path. K type events are sometimes terminated by fast field changes that are similar to the return stroke initiated by dart leaders; such K type events are the in-cloud analog of the dart leader return stroke process.

A leader-return-stroke consistent macroscopic model for calculations of return stroke current and its optical and electromagnetic emissions

NASA Astrophysics Data System (ADS)

Cai, Shuyao; Chen, Mingli; Du, Yaping; Qin, Zilong

2017-08-01

A downward lightning flash usually starts with a downward leader and an upward connecting leader followed by an upward return stroke. It is the preceding leader that governs the following return stroke property. Besides, the return stroke property evolves with height and time. These two aspects, however, are not well addressed in most existing return stroke models. In this paper, we present a leader-return stroke consistent model based on the time domain electric field integral equation, which is a growth and modification of Kumar's macroscopic model. The model is further extended to simulate the optical and electromagnetic emissions of a return stroke by introducing a set of equations relating the return stroke current and conductance to the optical and electromagnetic emissions. With a presumed leader initiation potential, the model can then simulate the temporal and spatial evolution of the current, charge transfer, channel size, and conductance of the return stroke, furthermore the optical and electromagnetic emissions. The model is tested with different leader initiation potentials ranging from -10 to -140 MV, resulting in different return stroke current peaks ranging from 2.6 to 209 kA with different return stroke speed peaks ranging from 0.2 to 0.8 speed of light and different optical power peaks ranging from 4.76 to 248 MW/m. The larger of the leader initiation potential, the larger of the return stroke current and speed. Both the return stroke current and speed attenuate exponentially as it propagates upward. All these results are qualitatively consistent with those reported in the literature.

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.

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.

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.

Mexican Americans are Less Likely to Return to Work Following Stroke: Clinical and Policy Implications.

PubMed

Skolarus, Lesli E; Wing, Jeffrey J; Morgenstern, Lewis B; Brown, Devin L; Lisabeth, Lynda D

2016-08-01

Greater poststroke disability and U.S. employment policies may disadvantage minority stroke survivors from returning to work. We explored ethnic differences in return to work among Mexican Americans (MAs) and non-Hispanic whites (NHWs) working at the time of their stroke. Stroke patients were identified from the population-based BASIC (Brain Attack Surveillance in Corpus Christi) study from August 2011 to December 2013. Employment status was obtained at baseline and 90-day interviews. Sequential logistic regression models were built to assess ethnic differences in return to work after accounting for the following: (1) age (<65 versus ≥65); (2) sex; (3) 90-day National Institutes of Health Stroke Scale (NIHSS); and (4) education (lower than high school versus high school or higher). Of the 729 MA and NHW stroke survivors who completed the baseline interview, 197 (27%) were working at the time of their stroke, of which 125 (63%) completed the 90-day outcome interview. Forty-nine (40%) stroke survivors returned to work by 90 days. MAs were less likely to return to work (OR = .45, 95% CI .22-.94) than NHWs. The ethnic difference became nonsignificant after adjusting for NIHSS (OR = .59, 95% CI .24-1.44) and further attenuated after adjusting for education (OR = .85, 95% CI .32- 2.22). The majority of stroke survivors did not return to work within 90 days of their stroke. MA stroke survivors were less likely to return to work after stroke than NHW stroke survivors which was due to their greater neurological deficits and lower educational attainment compared with that of NHW stroke survivors. Future work should focus on clinical and policy efforts to reduce ethnic disparities in return to work. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Correlated observations of three triggered lightning flashes

NASA Technical Reports Server (NTRS)

Idone, V. P.; Orville, R. E.; Hubert, P.; Barret, L.; Eybert-Berard, A.

1984-01-01

Three triggered lightning flashes, initiated during the Thunderstorm Research International Program (1981) at Langmuir Laboratory, New Mexico, are examined on the basis of three-dimensional return stroke propagation speeds and peak currents. Nonlinear relationships result between return stroke propagation speed and stroke peak current for 56 strokes, and between return stroke propagation speed and dart leader propagation speed for 32 strokes. Calculated linear correlation coefficients include dart leader propagation speed and ensuing return stroke peak current (32 strokes; r = 0.84); and stroke peak current and interstroke interval (69 strokes; r = 0.57). Earlier natural lightning data do not concur with the weak positive correlation between dart leader propagation speed and interstroke interval. Therefore, application of triggered lightning results to natural lightning phenomena must be made with certain caveats. Mean values are included for the three-dimensional return stroke propagation speed and for the three-dimensional dart leader propagation speed.

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.

Performance Study of Earth Networks Total Lightning Network using Rocket-Triggered Lightning Data in 2014

NASA Astrophysics Data System (ADS)

Heckman, S.

2015-12-01

Modern lightning locating systems (LLS) provide real-time monitoring and early warning of lightningactivities. In addition, LLS provide valuable data for statistical analysis in lightning research. It isimportant to know the performance of such LLS. In the present study, the performance of the EarthNetworks Total Lightning Network (ENTLN) is studied using rocket-triggered lightning data acquired atthe International Center for Lightning Research and Testing (ICLRT), Camp Blanding, Florida.In the present study, 18 flashes triggered at ICLRT in 2014 were analyzed and they comprise of 78negative cloud-to-ground return strokes. The geometric mean, median, minimum, and maximum for thepeak currents of the 78 return strokes are 13.4 kA, 13.6 kA, 3.7 kA, and 38.4 kA, respectively. The peakcurrents represent typical subsequent return strokes in natural cloud-to-ground lightning.Earth Networks has developed a new data processor to improve the performance of their network. Inthis study, results are presented for the ENTLN data using the old processor (originally reported in 2014)and the ENTLN data simulated using the new processor. The flash detection efficiency, stroke detectionefficiency, percentage of misclassification, median location error, median peak current estimation error,and median absolute peak current estimation error for the originally reported data from old processorare 100%, 94%, 49%, 271 m, 5%, and 13%, respectively, and those for the simulated data using the newprocessor are 100%, 99%, 9%, 280 m, 11%, and 15%, respectively. The use of new processor resulted inhigher stroke detection efficiency and lower percentage of misclassification. It is worth noting that theslight differences in median location error, median peak current estimation error, and median absolutepeak current estimation error for the two processors are due to the fact that the new processordetected more number of return strokes than the old processor.

Lightning Return-Stroke Current Waveforms Aloft, From Measured Field Change, Current, and Channel Geometry

NASA Technical Reports Server (NTRS)

Willett, J. C.; LeVine, D. M.

2002-01-01

Direct current measurements are available near the attachment point from both natural cloud-to-ground lightning and rocket-triggered lightning, but little is known about the rise time and peak amplitude of return-stroke currents aloft. We present, as functions of height, current amplitudes, rise times, and effective propagation velocities that have been estimated with a novel remote-sensing technique from data on 24 subsequent return strokes in six different lightning flashes that were triggering at the NASA Kennedy Space Center, FL, during 1987. The unique feature of this data set is the stereo pairs of still photographs, from which three-dimensional channel geometries were determined previously. This has permitted us to calculate the fine structure of the electric-field-change (E) waveforms produced by these strokes, using the current waveforms measured at the channel base together with physically reasonable assumptions about the current distributions aloft. The computed waveforms have been compared with observed E waveforms from the same strokes, and our assumptions have been adjusted to maximize agreement. In spite of the non-uniqueness of solutions derived by this technique, several conclusions seem inescapable: 1) The effective propagation speed of the current up the channel is usually significantly (but not unreasonably) faster than the two-dimensional velocity measured by a streak camera for 14 of these strokes. 2) Given the deduced propagation speed, the peak amplitude of the current waveform often must decrease dramatically with height to prevent the electric field from being over-predicted. 3) The rise time of the current wave front must always increase rapidly with height in order to keep the fine structure of the calculated field consistent with the observations.

Radiation from lightning return strokes over a finitely conducting earth

NASA Technical Reports Server (NTRS)

Le Vine, D. M.; Gesell, L.; Kao, Michael

1986-01-01

The effects of the conductivity of the earth on radiation from lightning return strokes are examined theoretically using a piecewise linear transmission line model for the return stroke. First, calculations are made of the electric field radiated during the return stroke, and then this electric field is used to compute the response of conventional AM radio receivers and electric field change systems during the return stroke. The calculations apply to the entire transient waveform (they are not restricted to the initial portions of the return stroke) and yield fast field changes and RF radiation in agreement with measurements made during real lightning. This research was motivated by measurements indicating that a time delay exists between the time of arrival of the fast electric field change and the RF radiation from first return strokes. The time delay is on the order of 20 microsec for frequencies in the HF-UHF range for lightning in Florida. The time delay is obtained theoretically in this paper. It occurs when both the effects of attenuation due to conductivity of the earth, and the finite velocity of propagation of the current pulse up the return stroke channel, are taken into account in the model.

Two-dimensional velocity, optical risetime, and peak current estimates for natural positive lightning return strokes

NASA Technical Reports Server (NTRS)

Mach, Douglas M.; Rust, W. D.

1993-01-01

Velocities, optical risetimes, and transmission line model peak currents for seven natural positive return strokes are reported. The average 2D positive return stroke velocity for channel segments of less than 500 m in length starting near the base of the channel is 0.8 +/- 0.3 x 10 exp 8 m/s, which is slower than the present corresponding average velocity for natural negative first return strokes of 1.7 +/- 0.7 x 10 exp 8/s. It is inferred that positive stroke peak currents in the literature, which assume the same velocity as negative strokes, are low by a factor of 2. The average 2D positive return stroke velocity for channel segments of greater than 500 m starting near the base of the channel is 0.9 +/- 0.4 x 10 exp 8 m/s. The corresponding average velocity for the present natural negative first strokes is 1.2 +/- 0.6 x 10 exp 8 m/s. No significant velocity change with height is found for positive return strokes.

Return to work predictors of stroke survivors and their spousal caregivers.

PubMed

Schulz, Celia H; Godwin, Kyler M; Hersch, Gayle I; Hyde, Leslie K; Irabor, Jocelyn J; Ostwald, Sharon K

2017-01-01

Return to work is an issue of concern for stroke survivors and their spouses. Ramifications may include loss of income and self-efficacy. This study describes the return to work patterns of stroke survivors and their spousal caregivers post stroke. One hundred fifty-nine dyads were examined for their return to work patterns at baseline (post hospital discharge) and then at 3 month intervals for one year. Relationships were determined between work and gender, age, ethnicity, education, type of insurance, type of stroke, location of stroke, motor and cognitive functional status, depression, mutuality, and life satisfaction. Low levels of return to work by stroke survivors (7.5%) and a small decrease in the amount of working caregivers (from 45.3% to 40.35%) were found one year post baseline. Variables that predicted return to work changed over the five data points except for younger age for the caregiver, which was consistently significant across all data points. Three case scenarios representative of working patterns are offered. Further research is needed regarding the return to work needs of stroke survivors and their spousal caregivers, particularly what role the occupational therapist may play in facilitating that process.

Variation in light intensity with height and time from subsequent lightning return strokes

NASA Technical Reports Server (NTRS)

Jordan, D. M.; Uman, M. A.

1983-01-01

Photographic measurements of relative light intensity as a function of height and time have been conducted for seven return strokes in two lightning flashes at 7.8 and 8.7 km ranges, using film which possesses an approximately constant spectral response in the 300-670 nm range. The amplitude of the initial light peak is noted to decrease exponentially with height, with a decay constant of 0.6-0.8 km. The logarithm of the peak light intensity near the ground is found to be approximately proportional to the initial peak electric field intensity, implying that the current decrease with height may be much slower than the light decrease. Absolute light intensity is presently estimated through the integration of the photographic signals from individual channel segments, in order to simulate the calibrated, all-sky photoelectric data of Guo and Krider (1982).

Returning to Paid Employment after Stroke: The Psychosocial Outcomes In StrokE (POISE) Cohort Study

PubMed Central

Hackett, Maree L.; Glozier, Nick; Jan, Stephen; Lindley, Richard

2012-01-01

Objectives To determine which early modifiable factors are associated with younger stroke survivors' ability to return to paid work in a cohort study with 12-months of follow-up conducted in 20 stroke units in the Stroke Services NSW clinical network. Participants Were aged >17 and <65 years, recent (within 28 days) stroke, able to speak English sufficiently to respond to study questions, and able to provide written informed consent. Participants with language or cognitive impairment were eligible to participate if their proxy provided consent and completed assessments on the participants' behalf. The main outcome measure was return to paid work during the 12 months following stroke. Results Of 441 consented participants (average age 52 years, 68% male, 83% with ischemic stroke), 218 were in paid full-time and 53 in paid part-time work immediately before their stroke, of whom 202 (75%) returned to paid part- or full-time work within 12 months. Being male, female without a prior activity restricting illness, younger, independent in activities of daily living (ADL) at 28 days after stroke, and having private health insurance was associated with return to paid work, following adjustment for other illnesses and a history of depression before stroke (C statistic 0·81). Work stress and post stroke depression showed no such independent association. Conclusions Given that independence in ADL is the strongest predictor of return to paid work within 12 months of stroke, these data reinforce the importance of reducing stroke-related disability and increasing independence for younger stroke survivors. Trial Registration Australian New Zealand Clinical Trials Registry ANZCTRN 12608000459325 PMID:22848610

Barriers and facilitators associated with return to work after stroke: a qualitative meta-synthesis.

PubMed

Brannigan, Colm; Galvin, Rose; Walsh, Mary E; Loughnane, Cliona; Morrissey, Emma-Jane; Macey, Chris; Delargy, Mark; Horgan, N Frances

2017-02-01

To enhance the employment outcomes of individuals who experience a stroke, it is essential to understand the factors that determine successful return to work. The aim of this systematic review was to examine barriers to and facilitators of return to work after stroke from the perspective of people with stroke through the process of a qualitative meta-synthesis. A systematic literature search was conducted. Studies that employed qualitative methods to explore the experiences of individuals with stroke around return to work after stroke were included. The methodological quality of the studies was assessed by two independent reviewers. Overarching themes, concepts and interpretations were extracted from each individual study, compared and meta-synthesized. Fifteen studies were included and the overall methodological quality of the studies was good. Four broad themes emerged as factors associated with return to work after stroke. These included (i) the nature of the effects of stroke, (ii) the preparatory environment, (iii) personal coping strategies and internal challenges and (iv) the meaning of work. Return to work after stroke is a complex process which can be facilitated or impeded by organizational, social or personal factors, as well as accessibility to appropriate services. Implications for Rehabilitation Following a period of dedicated inpatient rehabilitation, there is a need to integrate community-support services to optimize return to work among stroke survivors. A dedicated community stroke support liaison officer may help to facilitate the transition between the hospital and the community and workplace environment. Education provided by healthcare professionals is necessary in the community and the workplace to ensure that family, friends and employers are aware of the impairments, activity limitations and participation restrictions of the stroke survivor.

The propagation speed of a positive lightning return stroke

NASA Technical Reports Server (NTRS)

Idone, Vincent P.; Orville, Richard E.; Mach, Douglas M.; Rust, W. David

1987-01-01

The first direct determination of the propagation speed of a lightning return stroke lowering positive charge to ground has been made. This stroke was the third of eight otherwise negative strokes in a triggered lightning flash initiated at the Kennedy Space Center, FL. Two independent optical systems, one photographic and the other photoelectric, yielded common recordings for the third and fourth strokes; the respective two-dimensional return stroke propagation speeds were 1.0 vs 0.93 x 10 to the 8th m/s for the positive (third) stroke and 1.0 vs 1.0 x 10 to the 8th m/s for the fourth stroke. Using fast electric-field data, the positive stroke peak current was estimated to be 21 kA. Photoelectric data only yielded propagation speeds of 1.4, 1.6, 1.2, 1.3, 1.0 and 0.90 x 10 to the 8th m/s for the first, second and fifth through eighth return strokes, respectively.

Method and apparatus for determining return stroke polarity of distant lightning

NASA Technical Reports Server (NTRS)

Blakeslee, Richard J. (Inventor); Brook, Marx (Inventor)

1992-01-01

A method is described for determining the return stroke polarity of distant lightning for distances beyond 600 km by detecting the electric field associated with a return stroke of distant lightning, and processing the electric field signal to determine the polarity of the slow tail of the VLF waveform signal associated with the detected electric field. The polarity of the return stroke of distant lightning is determined based upon the polarity of the slow tail portion of the waveform.

Method and apparatus for determining return stroke polarity of distant lightning

NASA Technical Reports Server (NTRS)

Blakeslee, Richard J. (Inventor); Brook, Marx (Inventor)

1990-01-01

A method is described for determining the return stroke polarity of distant lightning for distances beyond 600 km by detecting the electric field associated with a return stroke of distant lightning, and processing the electric field signal to determine the polarity of the slow tail of the VLF waveform signal associated with the detected electric field. The polarity of the return stroke of distant lightning is determined based upon the polarity of the slow tail portion of the waveform.

Experimental and analytical investigation on metal damage suffered from simulated lightning currents

NASA Astrophysics Data System (ADS)

Yakun, LIU; Zhengcai, FU; Quanzhen, LIU; Baoquan, LIU; Anirban, GUHA

2017-12-01

The damage of two typical metal materials, Al alloy 3003 and steel alloy Q235B, subjected to four representative lightning current components are investigated by laboratory and analytical studies to provide fundamental data for lightning protection. The four lightning components simulating the natural lightning consist of the first return stroke, the continuing current of interval stroke, the long continuing current, and the subsequent stroke, with amplitudes 200 kA, 8 kA, 400 A, and 100 kA, respectively. The damage depth and area suffered from different lightning components are measured by the ultrasonic scanning system. And the temperature rise is measured by the thermal imaging camera. The results show that, for both Al 3003 and steel Q235B, the first return stroke component results in the largest damage area with damage depth 0.02 mm uttermost. The long continuing current component leads to the deepest damage depth of 3.3 mm for Al 3003 and much higher temperature rise than other components. The correlation analysis between damage results and lightning parameters indicates that the damage depth has a positive correlation with charge transfer. The damage area is mainly determined by the current amplitude and the temperature rise increases linearly with the charge transfer larger.

Positive attitudes and preserved high level of motor performance are important factors for return to work in younger persons after stroke: a national survey.

PubMed

Lindström, Britta; Röding, Jenny; Sundelin, Gunnevi

2009-09-01

Significant numbers of younger persons with stroke should be given the opportunity to return to work. The aim of this study was to investigate factors of importance for return to work among persons after first ever stroke, in the age range 18-55 years. A questionnaire was sent to all persons who had experienced a first ever stroke, 18-55 years of age, registered in the Swedish national quality register for stroke care, Riks-Stroke. Of the 1068 who answered the questionnaire, 855 (539 men and 316 women) were in paid employment before their stroke, and were included in this study. Sixty-five percent returned to work and, of these, an equal proportion were men and women. Significant factors associated with return to work were the perceived importance of work (odds ratio (OR) 5.10), not perceiving themselves as a burden on others (OR 3.33), support from others for return to work (OR 3.66), retaining the ability to run a short distance (OR 2.77), and higher socioeconomic codes (OR 2.12). A negative association was found between those rehabilitated in wards intended for younger persons and return to work (OR 0.37). External support from others, and positive attitudes towards return to work, were factors associated with successful return to work after stroke. Contrary to what was expected, independence in personal activities of daily living and cognitive factors were not associated with return to work to the same extent as persistent higher level of physical functions, such as ability to run a short distance.

Parameters of triggered-lightning flashes in Florida and Alabama

NASA Astrophysics Data System (ADS)

Fisher, R. J.; Schnetzer, G. H.; Thottappillil, R.; Rakov, V. A.; Uman, M. A.; Goldberg, J. D.

1993-12-01

Channel base currents from triggered lightning were measured at the NASA Kennedy Space Center, Florida, during summer 1990 and at Fort McClellan, Alabama, during summer 1991. Additionally, 16-mm cinematic records with 3- or 5-ms resolution were obtained for all flashes, and streak camera records were obtained for three of the Florida flashes. The 17 flashes analyzed here contained 69 strokes, all lowering negative charge from cloud to ground. Statistics on interstroke interval, no-current interstroke interval, total stroke duration, total stroke charge, total stroke action integral (∫ i2dt), return stroke current wave front characteristics, time to half peak value, and return stroke peak current are presented. Return stroke current pulses, characterized by rise times of the order of a few microseconds or less and peak values in the range of 4 to 38 kA, were found not to occur until after any preceding current at the bottom of the lightning channel fell below the noise level of less than 2 A. Current pulses associated with M components, characterized by slower rise times (typically tens to hundreds of microseconds) and peak values generally smaller than those of the return stroke pulses, occurred during established channel current flow of some tens to some hundreds of amperes. A relatively strong positive correlation was found between return stroke current average rate of rise and current peak. There was essentially no correlation between return stroke current peak and 10-90% rise time or between return stroke peak and the width of the current waveform at half of its peak value. Parameters of the lightning flashes triggered in Florida and Alabama are similar to each other but are different from those of triggered lightning recorded in New Mexico during the 1981 Thunderstorm Research International Program. Continuing currents that follow return stroke current peaks and last for more than 10 ms exhibit a variety of wave shapes that we have subdivided into four categories. All such continuing currents appear to start with a current pulse presumably associated with an M component. A brief summary of lightning parameters important for lightning protection, in a form convenient for practical use, is presented in an appendix.

Length bounds for connecting discharges in triggered lightning subsequent strokes

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

Idone, V.P.

1990-11-20

Highly time resolved streak recordings from nine subsequent strokes in four triggered flashes have been examined for evidence of the occurrence of upward connecting discharges. These photographic recordings were obtained with superior spatial and temporal resolution (0.3 m and 0.5 {lambda}s) and were examined with a video image analysis system to help delineate the separate leader and return stroke image tracks. Unfortunately, a definitive determination of the occurrence of connecting discharges in these strokes could not be made. The data did allow various determinations of an upper bound length for any possible connecting discharge in each stroke. Under the simplestmore » analysis approach possible, an 'absolute' upper bound set of lengths was measured that ranged from 12 to 27 m with a mean of 19 m; two other more involved analyses yielded arguably better upper bound estimates of 8-18 m and 7-26 m with means of 19 m; two other more involved analyses yielded arguably better upper bound estimates of 8-18 m and 7-26 m with means of 12 and 13 m, respectively. An additional set of low time-resolution telephoto recordings of the lowest few meters of channel revealed six strokes in these flashes with one or more upward unconnected channels originating from the lightning rod tip. The maximum length of unconnected channel seen in each of these strokes ranged from 0.2 to 1.6 m with a mean of 0.7 m. This latter set of observations is interpreted as indirect evidence that connecting discharges did occur in these strokes and that the lower bound for their length is about 1 m.« less

Statistical Evolution of the Lightning Flash

NASA Astrophysics Data System (ADS)

Zoghzoghy, F. G.; Cohen, M.; Said, R.; Inan, U. S.

2012-12-01

Natural lightning is one of the most fascinating and powerful electrical processes on Earth. To date, the physics behind this natural phenomenon are not fully understood, due primarily to the difficulty of obtaining measurements inside thunderstorms and to the wide range of timescales involved (from nanoseconds to seconds). Our aim is to use accurate lightning geo-location data from the National Lightning Detection Network (NLDN) to study statistical patterns in lightning, taking advantage of the fact that millions of lightning flashes occur around the globe every day. We present two sets of results, one involving the patterns of flashes in a storm, and a second involving the patterns of strokes in a flash. These patterns can provide a surrogate measure of the timescales and the spatial extents of the underlying physical processes. First, we study the timescales of charge buildup inside thunderstorms. We find that, following a lightning flash, the probability of another neighboring flash decreases and takes tens of seconds to recover. We find that this suppression effect is a function of flash type, stroke peak current, cloud-to-ground (CG) stroke multiplicity, and other lightning and geographical parameters. We find that the probabilities of subsequent flashes are more suppressed following oceanic lightning, or following flashes with higher peak currents and/or higher multiplicities (for CG flashes). Second, we use NLDN data to study the evolution of the strokes within a CG flash. A CG flash typically includes multiple return strokes, which can occur in the same channel or in multiple channels within a few kilometers. We cluster NLDN stroke data into flashes and produce the probability density function of subsequent strokes as a function of distance and time-delays relative to the previous stroke. Using this technique, we investigate processes which occur during the CG lightning flash with nanosecond to millisecond timescales. For instance, our results suggest that subsequent strokes that occur in a newly formed channel follow a pattern that propagates at a speed of ~200 km/s. We present our statistical techniques and discuss more thoroughly our work and results.

Characteristics of return stroke electric fields produced by lightning flashes at distances of 1 to 15 kilometers

NASA Technical Reports Server (NTRS)

Hopf, CH.

1991-01-01

Electric field derivative signals from single and multiple lightning strokes are presented. For about 25 pct. of all acquired waveforms, produced by return strokes, stepped leaders or intracloud discharges, type and distance of the signal source are known from the observations by an all sky video camera system. The analysis of the electric field derivative waveforms in the time domain shows a significant difference in the impulse width between return stroke signals and those of stepped leaders and intracloud discharges. In addition, the computed amplitude density spectrum of return stroke waveforms lies by a factor of 10 above that of stepped leaders and intracloud discharges in the frequency range from 50 to 500 kHz.

Modeling of transmission line exposure to direct lightning strokes

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

Rizk, F.A.M.

1990-10-01

The paper introduces a new model for assessing the exposure of free-standing structures and horizontal conductors above flat ground to direct lightning strokes. The starting point of this work is a recently developed criterion for positive leader inception, modified to account for positive leaders initiated under the influence of a negative descending lightning stroke. Subsequent propagation of the positive leader is analyzed to define the point of encounter of the two leaders which determines the attractive radius of a structure or the attractive lateral distance of a conductor. These parameters are investigated for a wide range of heights and return-strokemore » currents. A method for analyzing shielding failure and determining the critical shielding angle is also described. The predictions of the model are compared with field observations and previously developed models.« less

A numerical study on bow shocks around the lightning return stroke channel

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

Chen, Qiang, E-mail: cq0405@126.com; Chen, Bin, E-mail: emcchen@163.com; Yi, Yun

2015-03-15

Bow shock structures are important to various hydrodynamics and magnetohydrodynamics (MHD) phenomena in geophysics and astrophysics. The formation and propagation of bow shocks around the lightning return stroke channel are investigated based on the self-similar motion theory and simulated with a two-dimensional Eulerian finite volume resistive radiation MHD code. In this framework, as verification of theoretical models, the evolving structures of many quantities, such as the plasma density, temperature, pressure, shock velocity, and magnetic field, can be obtained, which present all the characteristics of bow shocks in the lightning return stroke processes. The evolution characteristics and the configuration of themore » curved return stroke channels, e.g., the non-ideal effects and the scaling laws, are discussed in detail. The results may have applications for some observed features of the return stroke channels and other phenomena in the lightning discharge plasmas.« less

Variation in light intensity with height and time from subsequent lightning return strokes

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

Jordan, D.M.; Uman, M.A.

1983-08-20

Relative light intensity has been measured photographically as a function of height and time for seven subsequent return strokes in two lightning flashes at ranges of 7.8 and 8.7 km. The film used was Kodak 5474 Shellburst, which has a roughly constant spectral response between 300 and 670 nm. The time resolution was about 1.0 ..mu..s, and the spatial resolution was about 4 m. The observed light signals consisted of a fast rise to peak, followed by a slower decrease to a relatively constant value. The amplitude of the initial light peak decreases exponentially with height with a decay constantmore » of about 0.6 to 0.8 km. The 20% to 80% rise time of the initial light signal is between 1 and 4 ..mu..s near ground and increases by an additional 1 to 2 ..mu..s by the time the return stroke reaches the cloud base, a height between 1 and 2 km. The light intensity 30 ..mu..s after the initial peak is relatively constant with height and has an amplitude that is 15% to 30% of the initial peak near the ground and 50% to 100% of the initial peak at cloud base. The logarithm of the peak light intensity near the ground is roughly proportional to the initial peak electric field intensity, and this in turn implies that the current decrease with height may be much slower than the light decrease. The absolute light intensity has been estimated by integrating the photographic signals from individual channel segments to simulate the calibrated all-sky photoelectric data of Guo and Krider (1982). Using this method, the authors find that the mean peak radiance near the ground is 8.3 x 10/sup 5/ W/m, with a total range from 1.4 x 10/sup 5/ to 3.8 x 10/sup 6/ W/m. 16 references, 11 figures.« less

The evolution of discharge current and channel radius in cloud-to-ground lightning return stroke process

NASA Astrophysics Data System (ADS)

Fan, Tingting; Yuan, Ping; Wang, Xuejuan; Cen, Jianyong; Chang, Xuan; Zhao, Yanyan

2017-09-01

The spectra of two negative cloud-to-ground lightning discharge processes with multi-return strokes are obtained by a slit-less high-speed spectrograph, which the temporal resolution is 110 μs. Combined with the synchronous electrical observation data and theoretical calculation, the physical characteristics during return strokes process are analysed. A positive correlation between discharge current and intensity of ionic lines in the spectra is verified, and based on this feature, the current evolution characteristics during four return strokes are investigated. The results show that the time from peak current to the half-peak value estimated by multi point-fitting is about 101 μs-139 μs. The Joule heat in per unit length of four return strokes channel is in the order of 105J/m-106 J/m. The radius of arc discharge channel is positively related to the discharge current, and the more intense the current is, the greater the radius of channel is. Furthermore, the evolution for radius of arc core channel in the process of return stroke is consistent with the change trend of discharge current after the peak value. Compared with the decay of the current, the temperature decreases more slowly.

Stepped-to-dart Leaders in Cloud-to-ground Lightning

NASA Astrophysics Data System (ADS)

Stolzenburg, M.; Marshall, T. C.; Karunarathne, S.; Karunarathna, N.; Warner, T.; Orville, R. E.

2013-12-01

Using time-correlated high-speed video (50,000 frames per second) and fast electric field change (5 MegaSamples per second) data for lightning flashes in East-central Florida, we describe an apparently rare type of subsequent leader: a stepped leader that finds and follows a previously used channel. The observed 'stepped-to-dart leaders' occur in three natural negative ground flashes. Stepped-to-dart leader connection altitudes are 3.3, 1.6 and 0.7 km above ground in the three cases. Prior to the stepped-to-dart connection, the advancing leaders have properties typical of stepped leaders. After the connection, the behavior changes almost immediately (within 40-60 us) to dart or dart-stepped leader, with larger amplitude E-change pulses and faster average propagation speeds. In this presentation, we will also describe the upward luminosity after the connection in the prior return stroke channel and in the stepped leader path, along with properties of the return strokes and other leaders in the three flashes.

Study protocol to a nationwide prospective cohort study on return to gainful occupation after stroke in Denmark 1996 - 2006

PubMed Central

2010-01-01

Background Successful return to work is regarded as one of the most important outcome factors for working-age post stroke patients. The present study will estimate the effect of various predictors on the odds of returning to work after stroke. Nearly twenty thousand 20-57 year-old stroke patients in Denmark who were gainfully occupied prior to the stroke will be included in the study. Methods/design Stroke patients will be followed prospectively through national registers. Multi-level logistic regression will be used to model the odds of being gainfully occupied ca. two years after the stroke as a function of the following predictors: Age (20-49 years, 50-57 years) gender, occupational class, self-employment (yes; no), onset calendar year (1996, 1997, ..., 2006), diagnosis (subarachnoid haemorrhage; intracerebral haemorrhage; cerebral infarction; stroke, not specified as haemorrhage or infarction) and 'type of municipality' (the variable is set to 1 if the person lived in a municipality which had a brain injury rehabilitation centre at the time of the stroke. Otherwise it is set to 0). Municipalities will be treated as the subjects while individual observations within municipalities are treated as correlated repeated measurements. Discussion Since our follow-up is done through registers and all people in the target population are included, the study is free from sampling bias, recall bias and non-response bias. The study is also strengthened by its size. The major weakness of the study is that it does not contain any stroke severity measures. Thus, it cannot accurately predict whether a particular stroke patient will in fact return to work. The study is, however, quite useful from a public health perspective. It can be used to estimate the proportion of patients in a certain group that is expected to return to work, and thereby provide a comparison material, which e.g. municipalities can use to evaluate their success in returning their stroke patients to work. PMID:20958997

Characteristics of the most intense lightning storm ever recorded at the CN Tower

NASA Astrophysics Data System (ADS)

Hussein, A. M.; Kazazi, S.; Anwar, M.; Yusouf, M.; Liatos, P.

2017-02-01

Lightning strikes to the CN Tower have been optically observed since 1978. In 1990, five independent systems started to operate to simultaneously record parameters of lightning strikes to the tower, including the time derivative of the current, the associated electric and magnetic fields, and the channel optical characteristics. On August 24, 2011, during an unusually severe lightning storm, video records showed that the CN Tower was struck with 52 lightning flashes within 84 min and 6.9 s. Thus, this storm produced, on average, a flash to the tower every 99 s. However, the CN Tower lightning current derivative measurement system only recorded 32 flashes, which were perfectly time-matched with 32 of the 52 video-recorded flashes. It is found that the current derivative measurement system recorded every video-recorded flash that contained at least one return stroke. Based on the analysis of video records, it is noted that each of the storm's 52 flashes contains an initial-stage current, proving that all flashes were upward initiated. This unique CN Tower storm - the most intense ever recorded at the tower - is here thoroughly analyzed, based on video and current records. The inter-flash time within the storm is found to vary between 10.6 s and 274 s, with an overall average of 98 s. It is also found that the inter-flash time between successive non-return-stroke flashes is on average 64% longer than that for successive flashes containing return strokes. Statistical analysis of video and current data clearly reveals that the time duration of flashes containing initial-stage currents and return strokes is on average 27% longer than that of flashes that only have initial-stage currents. Furthermore, it is important to note that the time duration of the initial-stage current in flashes containing no return strokes is on average 76% longer than that in flashes containing return strokes. Therefore, it is possible to conclude that if the time duration of the initial-stage current in a flash is long enough, resulting in large charge transfer, then there is less probability of having return strokes following it. The 32 current-recorded flashes contain a total of 156 return strokes, with an average multiplicity of 4.875. It is worth mentioning that during one decade, 1992-2001, the CN Tower current derivative measurement system only recorded 478 return strokes, demonstrating that the number of return strokes recorded at the tower within about 84 min is close to one third of those recorded at the tower during one decade. This finding clearly shows the great value and rarity of the presented extensive lightning current derivative data. Only one of the 32 current-recorded flashes is proved to be positive with a single return stroke. Based on current records, out of a total of 124 inter-stroke time intervals, 94% are found to be within 200 ms, with an overall inter-stroke time average of 68.1 ms. The maximum inter-stroke time recorded during this storm is 726.3 ms, the longest ever recorded at the CN Tower.

Exertional heat stroke and acute liver failure: a late dysfunction

PubMed Central

Carvalho, Ana Sofia; Rodeia, Simão C; Silvestre, Joana; Póvoa, Pedro

2016-01-01

Heat stroke (HS) is defined as a severe elevation of core body temperature along with central nervous system dysfunction. Exertional heat stroke (EHS) with acute liver failure (ALF) is a rare condition. The authors report the case of a 25-year-old man with a history of cognitive enhancers’ intake who developed hyperthermia and neurological impairment while running an outdoor marathon. The patient was cooled and returned to normal body temperature after 6 h. He subsequently developed ALF and was transferred to the intensive care unit. Over-the-counter drug intake may have been related to heat intolerance and contributed to the event. The patient was successfully treated with conservative measures. In the presence of EHS, it is crucial to act promptly with aggressive total body cooling, in order to prevent progression of the clinical syndrome. Liver function must also be monitored, since it can be a late organ dysfunction. PMID:26969359

Working after a stroke: survivors' experiences and perceptions of barriers to and facilitators of the return to paid employment.

PubMed

Alaszewski, Andy; Alaszewski, Helen; Potter, Jonathan; Penhale, Bridget

2007-12-30

This paper examines respondents' relationship with work following a stroke and explores their experiences including the perceived barriers to and facilitators of a return to employment. Our qualitative study explored the experiences and recovery of 43 individuals under 60 years who had survived a stroke. Participants, who had experienced a first stroke less than three months before and who could engage in in-depth interviews, were recruited through three stroke services in South East England. Each participant was invited to take part in four interviews over an 18-month period and to complete a diary for one week each month during this period. At the time of their stroke a minority of our sample (12, 28% of the original sample) were not actively involved in the labour market and did not return to the work during the period that they were involved in the study. Of the 31 participants working at the time of the stroke, 13 had not returned to work during the period that they were involved in the study, six returned to work after three months and nine returned in under three months and in some cases virtually immediately after their stroke. The participants in our study all valued work and felt that working, especially in paid employment, was more desirable than not working. The participants who were not working at the time of their stroke or who had not returned to work during the period of the study also endorsed these views. However they felt that there were a variety of barriers and practical problems that prevented them working and in some cases had adjusted to a life without paid employment. Participants' relationship with work was influenced by barriers and facilitators. The positive valuations of work were modified by the specific context of stroke, for some participants work was a cause of stress and therefore potentially risky, for others it was a way of demonstrating recovery from stroke. The value and meaning varied between participants and this variation was related to past experience and biography. Participants who wanted to work indicated that their ability to work was influenced by the nature and extent of their residual disabilities. A small group of participants had such severe residual disabilities that managing everyday life was a challenge and that working was not a realistic prospect unless their situation changed radically. The remaining participants all reported residual disabilities. The extent to which these disabilities formed a barrier to work depended on an additional range of factors that acted as either barriers or facilitator to return to work. A flexible working environment and supportive social networks were cited as facilitators of return to paid employment. Participants in our study viewed return to work as an important indicator of recovery following a stroke. Individuals who had not returned to work felt that paid employment was desirable but they could not overcome the barriers. Individuals who returned to work recognized the barriers but had found ways of managing them.

Association of multiple ischemic strokes with mortality in incident hemodialysis patients: an application of multistate model to determine transition probabilities in a retrospective observational cohort.

PubMed

Wetmore, James B; Mahnken, Jonathan D; Phadnis, Milind A

2016-09-21

Little is known about the effect of multiple, or subsequent, ischemic strokes in patients receiving hemodialysis. We undertook a retrospective cohort study of incident hemodialysis patients with Medicare coverage who had experienced a first ischemic stroke. Factors associated with either a subsequent ischemic stroke or death following a first new stroke were modeled. A multistate model with Cox proportional hazards was used to predict transition probabilities from first ischemic stroke to either subsequent stroke or to death, and the demographic and clinical factors associated with the respective transition probabilities were determined. Effect of a subsequent ischemic stroke on survival was quantified. Overall, 12,054 individuals (mean age 69.7 years, 41.3 % male, 53.0 % Caucasian and 34.0 % African-American) experienced a first new ischemic stroke. Female sex was associated with an increased risk of having a subsequent ischemic stroke (adjusted hazard ratio 1.37, 95 % confidence intervals 1.20 - 1.56, P < 0.0001); African-Americans, as compared to Caucasians, had lower likelihood of dying after a first new ischemic stroke (0.81, 0.77 - 0.85, P < 0.0001). A subsequent stroke trended towards having a higher likelihood of transitioning to death compared to a first new ischemic stroke on dialysis (1.72, 0.96 - 3.09, P = 0.071). When a subsequent ischemic stroke occurs at 24 months, probability of survival dropped >15 %, in absolute terms, from 0.254 to 0.096, with substantial drops observed at subsequent time points such that the probability of survival was more than halved. Likelihood of subsequent ischemic stroke and of survival in hemodialysis patients appears to vary by sex and race: females are more likely than males to experience a subsequent ischemic stroke, and Caucasians are more likely than African-Americans to die after a first new ischemic stroke. The risk of a transitioning to a subsequent stroke (after having had a first) increases until about 1 year, then decreases. Subsequent strokes are associated with decreased probability of survival, an effect which increases as time since first stroke elapses. This information may be of assistance to clinicians when counseling hemodialysis patients about the implications of recurrent ischemic stroke.

Power spectra at radio frequency of lightning return stroke waveforms

NASA Technical Reports Server (NTRS)

Lanzerotti, L. J.; Thomson, D. J.; Maclennan, C. G.; Rinnert, K.; Krider, E. P.

1989-01-01

The power spectra of the wideband (10 Hz to 100 kHz) magnetic field signals in a number of lightning return strokes (primarily first return strokes) measured during a lightning storm which occurred in Lindau, West Germany in August, 1984 have been calculated. The RF magnetic field data were obtained with the engineering unit of the Galileo Jupiter Probe lightning experiment. The spectra of the magnetic field data definitely show fine structure, with two or three distinct peaks appearing in the spectra of many of the waveforms. An enhancement of power at frequencies of about 60-70 kHz is often seen in the spectra of the waveform time segments preceding and following the rise-to-peak amplitude of the return stroke.

Post-stroke fatigue and return to work: a 2-year follow-up.

PubMed

Andersen, G; Christensen, D; Kirkevold, M; Johnsen, S P

2012-04-01

Post-stroke fatigue may affect the ability to return to work but quantitative studies are lacking. We included 83 first-ever stroke patients <60 years and employed either full-time (n = 77) or part-time (n = 6) at baseline. The patients were recruited from stroke units at Aarhus University Hospital between 2003 and 2005 and were followed for 2 years. Fatigue was assessed by the Multidimensional Fatigue Inventory. Pathological fatigue was defined as a score ≥12 on the General Fatigue dimension. Return to paid work was defined as working at least 10 h per week. Data were analyzed using multivariable logistic regression. A total of 58% of patients had returned to paid work after 2 years. The adjusted Odds Ratio (OR) for returning to paid work was 0.39 (95% confidence interval (CI) 0.16-1.08) for patients with a General Fatigue score ≥12 at baseline. Persisting pathological fatigue after 2 years of follow-up was associated with a lower chance of returning to paid work [adjusted OR 0.29 (95% CI 0.11-0.74)]. Higher scores of General Fatigue at follow-up also correlated negatively with the chance of returning to paid work when analyzing fatigue on a continuous scale (adjusted OR 0.87, 95% CI 0.80-0.94 for each point increase in General Fatigue). Post-stroke fatigue appears to be an independent determinant of not being able to resume paid work following stroke. © 2011 John Wiley & Sons A/S.

Cloud-to-ground lightning flash characteristics from June 1984 through May 1985

NASA Technical Reports Server (NTRS)

Orville, Richard E.; Weisman, Robert A.; Pyle, Richard B.; Henderson, Ronald W.; Orville, Richard E., Jr.

1987-01-01

A magnetic direction-finding network for the detection of lightning cloud-to-ground strikes has been installed along the east coast of the United States. Time, location, flash polarity, stroke count, and peak signal amplitude are recorded in real time. The data were recorded from Maine to North Carolina and as far west as Ohio; analyses were restricted to flashes within 300 km of a direction finder. Measurements of peak signal strength have been obtained from 720,284 first return strokes lowering negative charge. The resulting distribution indicates that few negative strokes have peak currents exceeding 100 kA. Measurements have also been obtained of peak signal strength from 17,694 first return strokes lowering positive charge. These strokes have a median peak current of 45 kA, with some peak currents reaching 300-400 kA. The median peak signal strength and the peak current, double from summer to winter for both negative and positive first return strokes. The polarity of ground flashes is observed to be less than 5 percent positive throughout the summer and early fall, then increases to over 50 percent during the winter, and returns to less than 10 percent in early spring. The percent of positive flashes with one stroke is observed to be approximately 90 percent throughout the year. The percent of negative flashes with one stroke is observed to increase from 40 percent in the summer to approximately 80 percent in January, returning to less than 50 percent in the spring.

Enterprise size and return to work after stroke.

PubMed

Hannerz, Harald; Ferm, Linnea; Poulsen, Otto M; Pedersen, Betina Holbæk; Andersen, Lars L

2012-12-01

It has been hypothesised that return to work rates among sick-listed workers increases with enterprise size. The aim of the present study was to estimate the effect of enterprise size on the odds of returning to work among previously employed stroke patients in Denmark, 2000-2006. We used a prospective design with a 2 year follow-up period. The study population consisted of 13,178 stroke patients divided into four enterprise sizes categories, according to the place of their employment prior to the stroke: micro (1-9 employees), small (10-49 employees), medium (50-249 employees) and large (>250 employees). The analysis was based on nationwide data on enterprise size from Statistics Denmark merged with data from the Danish occupational hospitalisation register. We found a statistically significant association (p = 0.034); each increase in enterprise size category was followed by an increase in the estimated odds of returning to work. The chances of returning to work after stroke increases as the size of enterprise increases. Preventive efforts and research aimed at finding ways of mitigating the effect are warranted.

Fine structure in RF spectra of lightning return stroke wave forms

NASA Technical Reports Server (NTRS)

Lanzerotti, L. J.; Thomson, D. J.; Maclennan, C. G.; Rinnert, K.; Krider, E. P.

1988-01-01

The power spectra of the wide-band (10 Hz to 100 kHz) magnetic-field signals for a number of lightning return strokes measured during a thunderstorm which occurred in Lindau in August, 1984 have been calculated. The RF magnetic field data are obtained with the engineering unit of the Galileo Jupiter Probe lightning experiment. Each return stroke data stream is passed through an adaptive filter designed to whiten its spectrum. The spectra of the magnetic field data definitely show fine structure, with two or three distinct peaks in the spectra of many of the waveforms. A peak at f of about 60-70 kHz is often seen in the power spectra of the waveform time segments preceding and following the rise-to-peak amplitude of the return stroke.

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/

Returning to Work after the Onset of Illness: Experiences of Right Hemisphere Stroke Survivors

ERIC Educational Resources Information Center

Koch, Lynn; Egbert, Nichole; Coeling, Harriet; Ayers, Denise

2005-01-01

Experiences of right hemisphere stroke survivors in their attempts to return to work after the onset of stroke were explored through an interdisciplinary qualitative investigation. Key findings indicate that (a) participants experienced an array of functional limitations that precipitated employment changes; (b) employment changes had a…

The (im)possibilities of returning to work after a stroke.

PubMed

Norstedt, Maria

2017-01-01

What a stroke means for working-age persons has not been sufficiently studied from a sociological perspective. This article uses the empirical material of a larger study to describe and analyze how institutional practices and discourses influence attempts to return to work after a stroke. Semi-structured interviews were conducted with ten persons who have had a stroke and ten civil servants and professionals from the Swedish Public Employment Service, the Social Insurance Agency, and different health care institutions. The qualitative analysis was inspired by institutional ethnography. The analysis shows how persons who have had a stroke and civil servants and professionals in welfare organizations share the same goal: a return to working life for the former. The persons in this study related to, translated, and put into practice discourses of normality and employability in this process. However, there were, at times, conflicting institutional practices between the different organizations. Conflicting institutional practices connected to the discourses of normality and employability contribute to the difficulties that persons who have had a stroke face when trying to return to work after recovery.

The influence of the breakdown electric field in the configuration of lightning corona sheath on charge distribution in the channel

NASA Astrophysics Data System (ADS)

Ignjatovic, Milan; Cvetic, Jovan; Heidler, Fridolin; Markovic, Slavoljub; Djuric, Radivoje

2014-11-01

A model of corona sheath that surrounds the thin core of the lightning channel has been investigated by using a generalized traveling current source return stroke model. The lightning channel is modeled by a charged corona sheath that stretches around a highly conductive central core through which the main current flows. The channel core with the negatively charged outer channel sheath forms a strong electric field, with an overall radial orientation. The return stroke process is modeled as the negative leader charge in the corona sheath being discharged by the positive charge coming from the channel core. Expressions that describe how the corona sheath radius evolves during the return stroke are obtained from the corona sheath model, which predicts charge motion within the sheath. The corona sheath model, set forth by Maslowski and Rakov (2006), Tausanovic et al. (2010), Marjanovic and Cvetic (2009), Cvetic et al. (2011) and Cvetic et al. (2012), divides the sheath onto three zones: zone 1 (surrounding the channel core with net positive charge), zone 2 (surrounding zone 1 with negative charge) and zone 3 (the outer zone, representing uncharged virgin air). In the present study, we have assumed a constant electric field inside zone 1, as suggested by experimental research of corona discharges in coaxial geometry conducted by Cooray (2000). The present investigation builds upon previous studies by Tausanovic et al. (2010) and Cvetic et al. (2012) in several ways. The value of the breakdown electric field has been varied for probing its effect on channel charge distribution prior and during the return stroke. With the aim of investigating initial space charge distribution along the channel, total electric field at the outer surface of the channel corona sheath, just before the return stroke, is calculated and compared for various return stroke models. A self-consistent algorithm is applied to the generalized traveling current source return stroke model, so that the boundary condition for total electric field is fulfilled. The new density of space charge and the new radius of channel corona envelope, immediately before the return stroke stage, are calculated. The obtained results indicate a strong dependence of channel charge distribution on the breakdown electric field value. Among the compared return stroke models, transmission-line-type models have exhibited a good agreement with the predictions of the Gauss' law regarding total breakdown electric field on the corona sheath's outer surface. The generalized lightning traveling current source return stroke model gives similar results if the adjustment of the space charge density inside the corona sheath is performed.

Barriers and facilitators to staying in work after stroke: insight from an online forum

PubMed Central

Balasooriya-Smeekens, Chantal; Bateman, Andrew; Mant, Jonathan; De Simoni, Anna

2016-01-01

Objective To explore barriers and facilitators to staying in work following stroke. Design Qualitative analysis of posts regarding staying in work following stroke using the archives of an online forum for stroke survivors. Participants 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’. Setting Posts from UK stroke survivors and family members on Talkstroke, the forum of the Stroke Association, between 2004 and 2011. Results 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. Conclusions 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. PMID:27053267

Effect of early and late rehabilitation onset in a chronic rat model of ischemic stroke- assessment of motor cortex signaling and gait functionality over time.

PubMed

Nielsen, Rasmus K; Samson, Katrine L; Simonsen, Daniel; Jensen, Winnie

2013-11-01

The aim of the present study was to investigate the effects of ischemic stroke and onset of subsequent rehabilitation of gait function in rats. Nine male Sprague-Dawley rats were instrumented with a 16-channel intracortical (IC) electrode array. An ischemic stroke was induced within the hindlimb area of the left motor cortex. The rehabilitation consisted of a repetitive training paradigm over 28 days, initiated on day one ("Early-onset", 5 rats) and on day seven, ("Late-onset", 4 rats). Data were obtained from IC microstimulation tests, treadmill walking tests, and beam walking tests. Results revealed an expansion of the hindlimb representation within the motor cortex area and an increased amount of cortical firing rate modulation for the "Early-onset" group but not for the "Late-onset" group. Kinematic data revealed a significant change for both intervention groups. However, this difference was larger for the "Early-onset" group. Results from the beam walking test showed functional performance deficits following stroke which returned to pre-stroke level after the rehabilitative training. The results from the present study indicate the existence of a critical time period following stroke where onset of rehabilitative training may be more effective and related to a higher degree of true recovery.

Horizontal fields generated by return strokes

NASA Technical Reports Server (NTRS)

Cooray, Vernon

1991-01-01

Horizontal fields generated by return strokes play an important role in the interaction of lightning generated electric fields with power lines. In many of the recent investigations on the interaction of lightning electromagnetic fields with power lines, the horizontal field was calculated by employing the expression for the tilt of the electric field of a plane wave propagating over finitely conducting earth. The method is suitable for calculating horizontal fields generated by return strokes at distances as close as 200m. At these close ranges, the use of the wavetilt expression can cause large errors.

Submicrosecond risetimes in lightning return-stroke fields

NASA Technical Reports Server (NTRS)

Weidman, C. D.; Krider, E. P.

1980-01-01

Measurements of lightning electric field, E, and dE/dt signatures have been made near Tampa Bay, Florida, under conditions where the lightning locations were known and where the results were not significantly affected by the response time of the measuring system or groundwave propagation. The fast transitions found on the initial portion of return-stroke fields have 10-90% risetimes ranging from 40 to 200 nsec, with a mean of 90 nsec. The maximum field derivatives during return strokes range from 5 to 75 V/m per microsec with a mean of 29 V/m per microsec when normalized to a distance of 100 km. These field risetime and derivative values suggest that return-stroke currents contain large, submicrosecond components, and this in turn suggests that it may be necessary to reevaluate the possible effects of lightning and the performance of lightning-protection devices in many situations.

A unified engineering model of the first stroke in downward negative lightning

NASA Astrophysics Data System (ADS)

Nag, Amitabh; Rakov, Vladimir A.

2016-03-01

Each stroke in a negative cloud-to-ground lightning flash is composed of downward leader and upward return stroke processes, which are usually modeled individually. The first stroke leader is stepped and starts with preliminary breakdown (PB) which is often viewed as a separate process. We present the first unified engineering model for computing the electric field produced by a sequence of PB, stepped leader, and return stroke processes, serving to transport negative charge to ground. We assume that a negatively charged channel extends downward in a stepped fashion during both the PB and leader stages. Each step involves a current wave that propagates upward along the newly formed channel section. Once the leader attaches to ground, an upward propagating return stroke neutralizes the charge deposited along the channel. Model-predicted electric fields are in reasonably good agreement with simultaneous measurements at both near (hundreds of meters, electrostatic field component is dominant) and far (tens of kilometers, radiation field component is dominant) distances from the lightning channel. Relations between the features of computed electric field waveforms and model input parameters are examined. It appears that peak currents associated with PB pulses are similar to return stroke peak currents, and the observed variation of electric radiation field peaks produced by leader steps at different heights above ground is influenced by the ground corona space charge.

Calculations of lightning return stroke electric and magnetic fields above ground

NASA Technical Reports Server (NTRS)

Master, M. J.; Uman, M. A.; Ling, Y. T.; Standler, R. B.

1981-01-01

Lin et al., (1980) presented a lightning return stroke model with which return stroke electric and magnetic fields measured at ground level could be reproduced. This model and a modified version of it, in which the initial current peak decays with height above ground, are used to compute waveforms for altitudes from 0-10 km and at ranges of 20 m to 10 km. Both the original and modified models gave accurate predictions of measured ground-based fields. The use of the calculated fields in calibrating airborne field measurements from simultaneous ground and airborne data is discussed.

The changes on physical characteristics of lightning discharge plasma during individual return stroke process

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

Xu, He; Yuan, Ping; Cen, Jian-Yong

2014-03-15

A cloud-to-ground lightning with six return strokes has been recorded with a slit-less spectrograph in Qinghai province. According to the spectra of return strokes without continuous current, the electron density, the channel temperature, and the gas pressure have been calculated. Then, the correlativity of these parameters has been analyzed. The results indicate that the total intensity of spectra is positive correlated to the intensity of spectral line, they both decrease with time rapidly; furthermore, the channel temperature and the gas pressure decrease with time slowly in the similar trends.

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.

Calculation of induced voltages on overhead lines caused by inclined lightning strokes

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

Sakakibara, A.

1989-01-01

Equations to calculate the inducing scalar and vector potentials produced by inclined return strokes are shown. Equations are also shown for calculating the induced voltages on overhead lines where horizontal components of inducing vector potential exist. The adequacy of the calculation method is demonstrated by field experiments. Using these equations, induced voltages on overhead lines are calculated for a variety of directions of return strokes.

Stroke Stories | NIH MedlinePlus the Magazine

MedlinePlus

... of this page please turn Javascript on. Feature: Stroke Rehabilitation Stroke Stories Past Issues / Spring 2013 Table of Contents ... these well-known personalities suffered one or more strokes. In each case, he or she has returned ...

The influence of ground conductivity on the structure of RF radiation from return strokes

NASA Technical Reports Server (NTRS)

Levine, D. M.; Gesell, L.

1984-01-01

The combination of the finite conductivity of the Earth plus the propagation of the return stroke current up the channel which results in an apparent time delay between the fast field changes and RF radiation for distant observers is shown. The time delay predicted from model return strokes is on the order of 20 micro and the received signal has the characteristics of the data observed in Virginia and Florida. A piecewise linear model for the return stroke channel and a transmission line model for current propagation on each segment was used. Radiation from each segment is calculated over a flat Earth with finite conductivity using asymptotics approximations for the Sommerfeld integrals. The radiation at the observer is processed by a model AM radio receiver. The output voltage was calculated for several frequencies between HF-UHF assuming a system bandwidth (300 kHz) characteristic of the system used to collect data in Florida and Virginia. Comparison with the theoretical fast field changes indicates a time delay of 20 microns.

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

Chen, Qiang, E-mail: cq0405@126.com; Luoyang Electronic Equipment Testing Center, Luoyang 471000; Chen, Bin, E-mail: emcchen@163.com

The Rayleigh-Taylor (R-T) instabilities are important hydrodynamics and magnetohydrodynamics (MHD) phenomena that are found in systems in high energy density physics and normal fluids. The formation and evolution of the R-T instability at channel boundary during back-flow of the lightning return stroke are analyzed using the linear perturbation theory and normal mode analysis methods, and the linear growth rate of the R-T instability in typical condition for lightning return stroke channel is obtained. Then, the R-T instability phenomena of lightning return stroke are simulated using a two-dimensional Eulerian finite volumes resistive radiation MHD code. The numerical results show that themore » evolution characteristics of the R-T instability in the early stage of back-flow are consistent with theoretical predictions obtained by linear analysis. The simulation also yields more evolution characteristics for the R-T instability beyond the linear theory. The results of this work apply to some observed features of the return stroke channel and further advance previous theoretical and experimental work.« less

An electrodynamic description of lightning return strokes and dart leaders: Guided wave propagation along conducting cylindrical channels

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

Borovsky, J.E.

1995-02-20

The return-stroke breakdown pulse and the dart leader are treated as electric waves guided by conducting lightning channels; such waves are launched when current is injected into a conducting channel (producing the dart leader) or when charge on a channel begins to drain to Earth (producing the return stroke). The guided waves are self-consistent solutions to the full set of Maxwell`s equations, obeying the physical boundary conditions for cylindrical channels. These waves are shown (1) to move with velocities substantially slower than c along the channel, (2) to push current inside the lightning channel, (3) to move charge and voltagemore » along the channel, and (4) to transport energy along and into the channel via Poynting flux. The velocity of a guided wave is a function of only three parameters: the channel radius r{sub ch}, the channel temperature T, and the risetime {triangle}t of the wave front. These velocities are found to fall in the range of velocities of return strokes and of dart leaders. The dart leader and the return stroke are caused by the same type of guided electromagnetic waves: the difference in velocity is owed mostly to the difference in channel temperature. In the case of the dart leader the waves deliver Poynting flux along the outside of the channel down from a thundercloud generator to the downward-propagating wave front. At the wave front of the dart leader the delivered energy goes into heating the channel and into storage in the form of E{sup 2}/8{pi} around the newly charged channel. In the case of the return stroke the Poynting flux is localized to the vicinity of the wave front where stored energy E{sup 2}/8{pi} is delivered radially inward onto the channel to heat the channel in the propagating front. The net result of a dart leader and return stroke is that charge is moved from the cloud to the ground and that energy is moved from the cloud onto the channel. 123 refs., 11 figs., 5 tabs.« less

Some properties of negative cloud-to-ground flashes from observations of a local thunderstorm based on accurate-stroke-count studies

NASA Astrophysics Data System (ADS)

Zhu, Baoyou; Ma, Ming; Xu, Weiwei; Ma, Dong

2015-12-01

Properties of negative cloud-to-ground (CG) lightning flashes, in terms of number of strokes per flash, inter-stroke intervals and the relative intensity of subsequent and first strokes, were presented by accurate-stroke-count studies based on all 1085 negative flashes from a local thunderstorm. The percentage of single-stroke flashes and stroke multiplicity evolved significantly during the whole life cycle of the study thunderstorm. The occurrence probability of negative CG flashes decreased exponentially with the increasing number of strokes per flash. About 30.5% of negative CG flashes contained only one stroke and number of strokes per flash averaged 3.3. In a subset of 753 negative multiple-stroke flashes, about 41.4% contained at least one subsequent stroke stronger than the corresponding first stroke. Subsequent strokes tended to decrease in strength with their orders and the ratio of subsequent to first stroke peaks presented a geometric mean value of 0.52. Interestingly, negative CG flashes of higher multiplicity tended to have stronger initial strokes. 2525 inter-stroke intervals showed a more or less log-normal distribution and gave a geometric mean value of 62 ms. For CG flashes of particular multiplicity geometric mean inter-stroke intervals tended to decrease with the increasing number of strokes per flash, while those intervals associated with higher order strokes tended to be larger than those associated with low order strokes.

Analysis on the correlation between temperature and discharge characteristic of cloud-to-ground lightning discharge plasma with multiple return strokes

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

Qu Haiyan; Chang Zhengshi; Yuan Ping

2011-01-15

The spectra of cloud-to-ground lightning with multiple return strokes have been obtained by using a slitless spectrograph on the Chinese Tibet plateau. Combining the spectra with synchronous electrical information, the correlation among spectral properties, channel temperatures and discharge characteristics, and thermal effects of current is discussed for the first time. The results show that the channel plasma temperature varies significantly from stroke to stroke within a given flash, and the total intensity of spectra is directly proportional to the amplitude of electric field change. Moreover, the positive correlation has been confirmed between the channel plasma temperature and the thermal effectmore » which shows the effect of the electric current accumulation. It is inferred that the total intensity of the spectra should be directly proportional to the intensity of discharge current, and channel temperature is correlated positively with the energy transmission in one return stroke.« less

Exploring the experiences of rehabilitated stroke survivors and stakeholders with regard to returning to work in South- West Nigeria.

PubMed

Soeker, Mogammad Shaheed; Olaoye, Olumide Ayoola

2017-01-01

Stroke has been identified as a global cause of neurological disability with a resultant burden shared not only by the survivor but also by society. The resumption of an individual's role as a worker after having a stroke, is an important rehabilitation goal. South-West Nigeria has experienced a high incidence and prevalence of stroke, leaving a quarter of survivors with severe disabilities and difficulties in community integration after rehabilitation. The study was aimed at exploring and describing the experiences of rehabilitated stroke survivors and perceptions of stakeholders about stroke survivors returning to work in South-West Nigeria. A qualitative research design was used to explore these experiences and perceptions from 19 participants, comprising nine stroke survivors, two key informants, who were rehabilitation specialists, and eight caregivers of the respective stroke survivors. The researcher made use of focus groups with the caregivers and semi-structured interviews with the stroke survivors and rehabilitation specialists. The data from the study were analysed using thematic analysis. Three themes emerged: Themes one and two described the barriers experienced by the stroke survivors on returning to work. Theme three described the factors that facilitated the resumption of the worker role. The study findings clearly depicted the many barriers experienced by stroke survivors and how these negatively impact their worker roles. Limited facilitatory factors exist to assist stroke survivors in regard to adapting to their worker roles. Promoting participation of stroke survivors in work emanating from government policies was deemed to be a necessary recommendation for the study. These policies were seen to be achievable if rehabilitation resources were improved.

A study on the influence of corona on currents and electromagnetic fields predicted by a nonlinear lightning return-stroke model

NASA Astrophysics Data System (ADS)

De Conti, Alberto; Silveira, Fernando H.; Visacro, Silvério

2014-05-01

This paper investigates the influence of corona on currents and electromagnetic fields predicted by a return-stroke model that represents the lightning channel as a nonuniform transmission line with time-varying (nonlinear) resistance. The corona model used in this paper allows the calculation of corona currents as a function of the radial electric field in the vicinity of the channel. A parametric study is presented to investigate the influence of corona parameters, such as the breakdown electric field and the critical electric field for the stable propagation of streamers, on predicted currents and electromagnetic fields. The results show that, regardless of the assumed corona parameters, the incorporation of corona into the nonuniform and nonlinear transmission line model under investigation modifies the model predictions so that they consistently reproduce most of the typical features of experimentally observed lightning electromagnetic fields and return-stroke speed profiles. In particular, it is shown that the proposed model leads to close vertical electric fields presenting waveforms, amplitudes, and decay with distance in good agreement with dart leader electric field changes measured in triggered lightning experiments. A comparison with popular engineering return-stroke models further confirms the model's ability to predict consistent electric field waveforms in the close vicinity of the channel. Some differences observed in the field amplitudes calculated with the different models can be related to the fact that current distortion, while present in the proposed model, is ultimately neglected in the considered engineering return-stroke models.

Tortuosity of lightning return stroke channels

NASA Technical Reports Server (NTRS)

Levine, D. M.; Gilson, B.

1984-01-01

Data obtained from photographs of lightning are presented on the tortuosity of return stroke channels. The data were obtained by making piecewise linear fits to the channels, and recording the cartesian coordinates of the ends of each linear segment. The mean change between ends of the segments was nearly zero in the horizontal direction and was about eight meters in the vertical direction. Histograms of these changes are presented. These data were used to create model lightning channels and to predict the electric fields radiated during return strokes. This was done using a computer generated random walk in which linear segments were placed end-to-end to form a piecewise linear representation of the channel. The computer selected random numbers for the ends of the segments assuming a normal distribution with the measured statistics. Once the channels were simulated, the electric fields radiated during a return stroke were predicted using a transmission line model on each segment. It was found that realistic channels are obtained with this procedure, but only if the model includes two scales of tortuosity: fine scale irregularities corresponding to the local channel tortuosity which are superimposed on large scale horizontal drifts. The two scales of tortuosity are also necessary to obtain agreement between the electric fields computed mathematically from the simulated channels and the electric fields radiated from real return strokes. Without large scale drifts, the computed electric fields do not have the undulations characteristics of the data.

Triggered lightning spectroscopy: Part 1. A qualitative analysis

NASA Astrophysics Data System (ADS)

Walker, T. Daniel; Christian, Hugh J.

2017-08-01

The first high-speed spectra of triggered lightning have been obtained. During the summers of 2012 and 2013, spectra were recorded at the International Center for Lightning Research and Testing, Camp Blanding, FL. The spectra were recorded with a high-speed camera with a grism mounted in front of it. The triggered lightning channels observed were generally at low altitude in a region that included the copper wire. Spectral emissions were recorded at each phase: the initial stage, dart leader, return stroke, and continuing current. These spectra are separated into two major regions: soft ultraviolet to visible (3800-6200 Å) and visible to near infrared (6200-8700 Å). The emissions during the initial stage reflect those of a copper wire burn in air. The majority of the emissions are neutral copper. After the initial stage comes the first return stroke which contains no detected molecular emissions; however, it does contain neutral, singly, and doubly ionized nitrogen and oxygen, neutral argon, and neutral hydrogen. Occasionally, before a return stroke, the dart leader coming down the channel will be stepped. During these occasions the leader spectra resemble that of the return stroke but are dimmer and shorter lived. After the initial portion of the return stroke, there are often changes in the luminosity of the spectrum which corresponds with fluctuations in the continuing current. During these "reillumination phases" no singly or doubly ionized lines have been observed to reemerge over the detection threshold, only neutral emission features.

Horizontal electric fields from lightning return strokes

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

Thomson, E.M.; Uman, M.A.; Johnson, J.

1985-01-01

Measurements are presented of simultaneous horizontal and vertical electric fields from both close and distant lightning return strokes. The data were obtained during summer 1984 at the Kennedy Space Center, Florida, using an electrically isolated spherical antenna having a system bandwidth of 3 Hz to 5 MHz. Lightning signals were obtained from flashes at distances from a few to 100 kilometers. Since the horizontal electric field is in part determined by the local ground conductivity, that parameter was measured as a function of depth. The horizontal fields from lightning return strokes had typically 1/50 the peak amplitude of the verticalmore » fields and waveshapes which were consistant with available theory, as expressed by the ''wavetilt'' formula.« less

National survey of emergency physicians for transient ischemic attack (TIA) risk stratification consensus and appropriate treatment for a given level of risk.

PubMed

Perry, Jeffrey J; Losier, Justin H; Stiell, Ian G; Sharma, Mukul; Abdulaziz, Kasim

2016-01-01

Five percent of transient ischemic attack (TIA) patients have a subsequent stroke within 7 days. The Canadian TIA Score uses clinical findings to calculate the subsequent stroke risk within 7 days. Our objectives were to assess 1) anticipated use; 2) component face validity; 3) risk strata for stroke within 7 days; and 4) actions required, for a given risk for subsequent stroke. After a rigorous development process, a survey questionnaire was administered to a random sample of 300 emergency physicians selected from those registered in a national medical directory. The surveys were distributed using a modified Dillman technique. From a total of 271 eligible surveys, we received 131 (48.3%) completed surveys; 96.2% of emergency physicians would use a validated Canadian TIA Score; 8 of 13 components comprising the Canadian TIA Score were rated as Very Important or Important by survey respondents. Risk categories for subsequent stroke were defined as minimal-risk: 10% risk of subsequent stroke within 7 days. A validated Canadian TIA Score will likely be used by emergency physicians. Most components of the TIA Score have high face validity. Risk strata are definable, which may allow physicians to determine immediate actions, based on subsequent stroke risk, in the emergency department.

Stroke patients' experiences of return to work.

PubMed

Medin, Jennie; Barajas, Josefin; Ekberg, Kerstin

2006-09-15

Purpose. The aim of this study was to describe the experience of return to work (RTW) after stroke from the patient's perspective.Method. Six patients who had their first ever stroke in 2001, were <65 years of age and were working at the time of their stroke were included. Information was obtained via an open-ended interview. The material was transcribed verbatim and analysed using Giorgi's empirical phenomenology.Results. Rehabilitation was perceived as primarily aimed at restoring bodily functions and a return to everyday activities, rather than at promoting a return to work. It was not experienced as adapted to the participants' needs or their age. The workplace was experienced as very important in the rehabilitation process. When the informants experienced that the rehabilitation professionals were not taking action, they took control of the situation themselves. The informants expressed pride in their own capacity to take the initiative and in their ability to take action. Both self-employed and employed informants said they had possibilities and opportunities to take action since their work situation was flexible. The informants' adaptation to a new role at work was perceived as facilitated by the understanding and positive attitude of co-workers.Conclusion. Among this group of stroke patients, the individual patient's capacity and ability to return to work was enhanced by motivation or "will" and self-efficacy in combination with external support. Self-efficacy was not only a personal trait or internal factor; it was enhanced and encouraged in interaction with contextual conditions. There are similarities between the RTW process and processes of health promotion.

Characteristics of VLF/LF Sferics from Elve-producing Lightning Discharges

NASA Astrophysics Data System (ADS)

Blaes, P.; Zoghzoghy, F. G.; Marshall, R. A.

2013-12-01

Lightning return strokes radiate an electromagnetic pulse (EMP) which interacts with the D-region ionosphere; the largest EMPs produce new ionization, heating, and optical emissions known as elves. Elves are at least six times more common than sprites and other transient luminous events. Though the probability that a lightning return stroke will produce an elve is correlated with the return stroke peak current, many large peak current strokes do not produce visible elves. Apart from the lightning peak current, elve production may depend on the return stroke speed, lightning altitude, and ionospheric conditions. In this work we investigate the detailed structure of lightning that gives rise to elves by analyzing the characteristics of VLF/LF lightning sferics in conjunction with optical elve observations. Lightning sferics were observed using an array of six VLF/LF receivers (1 MHz sample-rate) in Oklahoma, and elves were observed using two high-speed photometers pointed over the Oklahoma region: one located at Langmuir Laboratory, NM and the other at McDonald Observatory, TX. Hundreds of elves with coincident LF sferics were observed during the summer months of 2013. We present data comparing the characteristics of elve-producing and non-elve producing lightning as measured by LF sferics. In addition, we compare these sferic and elve observations with FDTD simulations to determine key properties of elve-producing lightning.

Influence of the rehabilitation outcome on returning to drive after neurological impairment.

PubMed

Čižman, Urša Š; Vidmar, Gaj; Drnovšek, Petra

2017-06-01

In traumatic brain injury (TBI) and stroke rehabilitation, the question of reintegration of the driver into traffic is faced very often. Driving is an important domain and for some patients, return to driving represents a crucial event for community inclusion. The aim of our study was to examine the utility of Glasgow Coma Scale within the first 24 h of injury and the Functional Independence Measure (FIM) at rehabilitation admission for predicting the return to driving. We included 72 patients after TBI or stroke. Driving outcome was assessed in terms of being allowed to drive without restrictions as opposed to failing the test or being allowed to drive with restrictions. We examined two samples: the TBI patients only and the entire sample including patients after stroke. The results indicate that for TBI patients, Glasgow Coma Scale and motor FIM could be predictors of driving outcome; in the entire sample, the unrestricted driving outcome was also associated with a high score on the FIM motor scale. Early prediction of return to driving after TBI and stroke is important for the patients, their families and the rehabilitation teams to set realistic goals that enable the best possible reintegration after rehabilitation.

Survey of survivors' perspective on return to work after stroke.

PubMed

Hartke, Robert J; Trierweiler, Robert

2015-10-01

To describe the development and results of a detailed survey on return to work (RTW) after stroke completed by survivors at various stages of recovery. This study used a multi-method qualitative and quantitative research strategy to design and implement a 39-item survey for stroke survivors. Individual interviews, focus groups, and working committees were used to conceptualize the issues and translate them into a survey format. Surveys were distributed in regular and electronic mail. Groups of rehabilitation professionals, employers, and stroke survivors were assembled to review findings and obtain feedback to aide in interpretation. Overall 715 surveys were completed. The respondents were on average 54 years of age, mostly white, well-educated, urban dwelling, and in skilled occupations. Results are described in seven areas: financial, stroke impairments, organizational, work and psychological issues, interpersonal support, and therapy. Several salient findings are described including the role of fatigue, under utilization of vocational rehabilitation (VR) services, and motivational factors related to finances, self-esteem, work, and workplace relationships. Although earning an income is a strong motivation to RTW, salary decreases in importance when compared with other psychological benefits. Fatigue was rated as the second highest impairment barrier to RTW and persisted as a relevant impediment over time. Attitudes of co-workers and flexibility in work schedule were viewed as most helpful to the RTW process, whereas work stress was viewed as the greatest impediment to return. Only 24% of the sample received VR counseling with more respondents receiving counseling if they returned 6 months or longer after their stroke. Other trends and clinical and research implications are discussed.

Non-collinear valve actuator

NASA Technical Reports Server (NTRS)

Richard, James A. (Inventor)

2012-01-01

A non-collinear valve actuator includes a primary actuating system and a return spring system with each applying forces to a linkage system in order to regulate the flow of a quarter-turn valve. The primary actuating system and return spring system are positioned non-collinearly, which simply means the primary actuating system and return spring system are not in line with each other. By positioning the primary actuating system and return spring system in this manner, the primary actuating system can undergo a larger stroke while the return spring system experiences significantly less displacement. This allows the length of the return spring to be reduced due to the minimization of displacement thereby reducing the weight of the return spring system. By allowing the primary actuating system to undergo longer strokes, the weight of the primary actuating system may also be reduced. Accordingly, the weight of the non-collinear valve actuator is reduced.

Developing stroke-specific vocational rehabilitation: a soft systems analysis of current service provision

PubMed Central

Radford, Kathryn; Grant, Mary; Terry, Jane

2014-01-01

Purpose: This study aimed to clarify the existing service provision of stroke-specific vocational rehabilitation (VR) in one English county, in order to facilitate future service development. Method: Using soft systems methodology, services in Health, Social Care, Department of Work and Pensions, the voluntary and private sectors, which were identified as supporting return to work after stroke, were mapped using a mixed-methodology approach. Results: A lack of a sanctioned VR pathway meant access to support relied on brokered provision and tacit knowledge. The timing of an intervention was complex and there was a substantial degree of unmet need for mild stroke patients. VR was seen as “non-essential” due to competing commissioning priorities. Service providers from all sectors lacked training and cross-sector partnerships were tenuous and provider roles unclear. Conclusions: Stroke-specific VR should be delivered by an integrated, cross-sector multi-disciplinary team and integrated commissioning between health and other sectors is necessary. Although early intervention is important, support later on in the recovery process is also necessary. Service providers need adequate training to meet the needs of stroke survivors wishing to return to work and better awareness of best practice guidelines. Business cases which demonstrate the efficacy and cost-effectiveness of VR are vital. Implications for Rehabilitation The timeliness of a vocational rehabilitation (VR) intervention is complex; services need to be responsive to the changing needs of the stroke survivor throughout their recovery process and have better mechanisms to ensure re-entry into the stroke pathway is possible. Return to work is a recognised health outcome; health services need to develop better mechanisms for interagency/cross sector working and liaison with employers and not assume that VR is beyond their remit. Therapists and non-health service providers should receive sufficient training to meet the needs of stroke survivors wishing to return to work. Rehabilitation teams must decide how to implement national guidance within existing resources and what training is needed to deploy SSVR. The lack of a sanctioned pathway results in disorganised and patchy provision of VR for stroke survivors; mild stroke patients can fall through the net and receive little or no support. The journey back to work commences at the point of stroke. Mechanisms for identifying acute stroke survivors who were working at onset and for assessing the impact of the stroke on their work need to be put in place. The entire MDT has a role to play. In the absence of a VR specialist, even patients without obvious disability should be referred for ongoing rehabilitation with detailed work assessment and signposted to employment specialists e.g. disability employment advisors EARLY after stroke. Health-based VR interventions can influence work return and job retention. However, therapists must routinely measure work outcomes to inform their business case and be encouraged to demonstrate these outcomes to local commissioners. Commissioners should consider emerging evidence of early VR interventions on reduced length of stay, health and social care resource use and the wider health benefits of maintaining employment. PMID:23692389

Developing stroke-specific vocational rehabilitation: a soft systems analysis of current service provision.

PubMed

Sinclair, Emma; Radford, Kathryn; Grant, Mary; Terry, Jane

2014-01-01

This study aimed to clarify the existing service provision of stroke-specific vocational rehabilitation (VR) in one English county, in order to facilitate future service development. Using soft systems methodology, services in Health, Social Care, Department of Work and Pensions, the voluntary and private sectors, which were identified as supporting return to work after stroke, were mapped using a mixed-methodology approach. A lack of a sanctioned VR pathway meant access to support relied on brokered provision and tacit knowledge. The timing of an intervention was complex and there was a substantial degree of unmet need for mild stroke patients. VR was seen as "non-essential" due to competing commissioning priorities. Service providers from all sectors lacked training and cross-sector partnerships were tenuous and provider roles unclear. Stroke-specific VR should be delivered by an integrated, cross-sector multi-disciplinary team and integrated commissioning between health and other sectors is necessary. Although early intervention is important, support later on in the recovery process is also necessary. Service providers need adequate training to meet the needs of stroke survivors wishing to return to work and better awareness of best practice guidelines. Business cases which demonstrate the efficacy and cost-effectiveness of VR are vital. Implications for Rehabilitation The timeliness of a vocational rehabilitation (VR) intervention is complex; services need to be responsive to the changing needs of the stroke survivor throughout their recovery process and have better mechanisms to ensure re-entry into the stroke pathway is possible. Return to work is a recognised health outcome; health services need to develop better mechanisms for interagency/cross sector working and liaison with employers and not assume that VR is beyond their remit. Therapists and non-health service providers should receive sufficient training to meet the needs of stroke survivors wishing to return to work. Rehabilitation teams must decide how to implement national guidance within existing resources and what training is needed to deploy SSVR. The lack of a sanctioned pathway results in disorganised and patchy provision of VR for stroke survivors; mild stroke patients can fall through the net and receive little or no support. The journey back to work commences at the point of stroke. Mechanisms for identifying acute stroke survivors who were working at onset and for assessing the impact of the stroke on their work need to be put in place. The entire MDT has a role to play. In the absence of a VR specialist, even patients without obvious disability should be referred for ongoing rehabilitation with detailed work assessment and signposted to employment specialists e.g. disability employment advisors EARLY after stroke. Health-based VR interventions can influence work return and job retention. However, therapists must routinely measure work outcomes to inform their business case and be encouraged to demonstrate these outcomes to local commissioners. Commissioners should consider emerging evidence of early VR interventions on reduced length of stay, health and social care resource use and the wider health benefits of maintaining employment.

Associations between DSM-IV mental disorders and subsequent non-fatal, self-reported stroke.

PubMed

Swain, Nicola R; Lim, Carmen C W; Levinson, Daphna; Fiestas, Fabian; de Girolamo, Giovanni; Moskalewicz, Jacek; Lepine, Jean-Pierre; Posada-Villa, Jose; Haro, Josep Maria; Medina-Mora, María Elena; Xavier, Miguel; Iwata, Noboru; de Jonge, Peter; Bruffaerts, Ronny; O'Neill, Siobhan; Kessler, Ron C; Scott, Kate M

2015-08-01

To examine the associations between a wide range of mental disorders and subsequent onset of stroke. Lifecourse timing of stroke was examined using retrospectively reconstructed data from cross-sectional surveys. Data from the World Mental Health Surveys were accessed. This data was collected from general population surveys over 17 countries of 87,250 adults. The Composite International Diagnostic Interview retrospectively assessed lifetime prevalence and age at onset of DSM-IV mental disorders. A weighted subsample (n=45,288), was used for analysis in the present study. Survival analyses estimated associations between first onset of mental disorders and subsequent stroke onset. Bivariate models showed that 12/16 mental disorders were associated with subsequent stroke onset (ORs ranging from 1.6 to 3.8). However, after adjustment for mental disorder comorbidity and smoking, only significant relationships between depression and stroke (OR 1.3) and alcohol abuse and stroke (OR 1.5) remained. Among females, having a bipolar disorder was also associated with increased stroke incidence (OR 2.1). Increasing number of mental disorders was associated with stroke onset in a dose-response fashion (OR 3.3 for 5+ disorders). Depression and alcohol abuse may have specific associations with incidence of non-fatal stroke. General severity of psychopathology may be a more important predictor of non-fatal stroke onset. Mental health treatment should be considered as part of stroke risk prevention. Limitations of retrospectively gathered cross sectional surveys design mean further research on the links between mental health and stroke incidence is warranted. Copyright © 2015 Elsevier Inc. All rights reserved.

Horizontal electric fields from lightning return strokes

NASA Technical Reports Server (NTRS)

Thomson, E. M.; Medelius, P. J.; Rubinstein, M.; Uman, M. A.; Johnson, J.

1988-01-01

An experiment to measure simultaneously the wideband horizontal and vertical electric fields from lightning return strokes is described. Typical wave shapes of the measured horizontal and vertical fields are presented, and the horizontal fields are characterized. The measured horizontal fields are compared with calculated horizontal fields obtained by applying the wavetilt formula to the vertical fields. The limitations and sources of error in the measurement technique are discussed.

Dynamics of a lightning corona sheath—A constant field approach using the generalized traveling current source return stroke model

NASA Astrophysics Data System (ADS)

Cvetic, Jovan; Heidler, Fridolin; Markovic, Slavoljub; Radosavljevic, Radovan; Osmokrovic, Predrag

2012-11-01

A generalized lightning traveling current source return stroke model has been used to examine the characteristics of the lightning channel corona sheath surrounding a thin channel core. A model of the lightning channel consisting of a charged corona sheath and a narrow, highly conducting central core that conducts the main current flow is assumed. Strong electric field, with a predominant radial direction, has been created during the return stroke between the channel core and the outer channel sheath containing the negative charge. The return stroke process is modeled with the positive charge coming from the channel core discharging the negative leader charge in the corona sheath. The corona sheath model that predicts the charge motion in the sheath is used to derive the expressions of the sheath radius vs. time during the return stroke. According to the corona sheath model proposed earlier by Maslowski and Rakov (2006) and Maslowski et al. (2009), it consists of three zones, zone 1 (surrounding channel core with net positive charge), zone 2 (surrounding zone 1 with negative charge) and zone 3 (outer zone representing the virgin air without charges). We adopted the assumption of a constant electric field inside zone 1 of the corona sheath observed in the experimental research of corona discharges in a coaxial geometry by Cooray (2000). This assumption seems to be more realistic than the assumption of a uniform corona space charge density used previously in the study of Maslowski and Rakov (2006), Marjanovic and Cvetic (2009), and Tausanovic et al. (2010). Applying the Gauss' law on the infinitesimally small cylindrical section of the channel the expressions for time-dependence of the radii of zones 1 and 2 during the return stroke are derived. The calculations have shown that the overall channel dynamics concerning electrical discharge is roughly 50% slower and the maximum radius of zone 1 is about 33% smaller compared to the corresponding values calculated in the study of Tausanovic et al. (2010).

Return Stroke Current Reflections in Rocket-Triggered Lightning

NASA Astrophysics Data System (ADS)

Caicedo, J.; Uman, M. A.; Jordan, D.; Biagi, C. J.; Hare, B.

2015-12-01

In the six years from 2009 to 2014, there have been eight triggered flashes at the ICLRT, from a total of 125, in which a total of ten return stroke channel-base currents exhibited a dip 3.0 to 16.6 μs after the initial current peak. Close range electric field measurements show a related dip following the initial electric field peak, and electric field derivative measurements show an associated bipolar pulse, confirming that this phenomenon is not an instrumentation effect in the current measurement. For six of the eight flashes, high-speed video frames show what appears to be suspended sections of unexploded triggering wire at heights of about 150 to 300 m that are illuminated when the upward current wave reaches them. The suspended wire can act as an impedance discontinuity, perhaps as it explodes, and cause a downward reflection of some portion of the upward-propagating current wave. This reflected wave travels down the channel and causes the dip in the measured channel-base current when it reaches ground and reflects upward. The modified transmission line model with exponential decay (MTLE) is used to model the close electric field and electric field derivatives of the postulated initial and reflected current waves, starting with the measured channel base current, and the results are compared favorably with measurements made at distances ranging from 92 to 444 m. From the measured time between current impulse initiation and the time the current reflection reaches the channel base and the current dip initiates, along with the reflection height from the video records, we find the average return stroke current speed for each of the ten strokes to be from 0.28 to 1.9×108 ms-1, with an error of ±0.01×108 ms-1 due to a ±0.1 μs uncertainty in the measurement. This represents the first direct measurement of return stroke current speed, all previous return stroke speed measurements being derived from the luminosity of the process.

Automated Studies of Continuing Current in Lightning Flashes

NASA Astrophysics Data System (ADS)

Martinez-Claros, Jose

Continuing current (CC) is a continuous luminosity in the lightning channel that lasts longer than 10 ms following a lightning return stroke to ground. Lightning flashes following CC are associated with direct damage to power lines and are thought to be responsible for causing lightning-induced forest fires. The development of an algorithm that automates continuing current detection by combining NLDN (National Lightning Detection Network) and LEFA (Langmuir Electric Field Array) datasets for CG flashes will be discussed. The algorithm was applied to thousands of cloud-to-ground (CG) flashes within 40 km of Langmuir Lab, New Mexico measured during the 2013 monsoon season. It counts the number of flashes in a single minute of data and the number of return strokes of an individual lightning flash; records the time and location of each return stroke; performs peak analysis on E-field data, and uses the slope of interstroke interval (ISI) E-field data fits to recognize whether continuing current (CC) exists within the interval. Following CC detection, duration and magnitude are measured. The longest observed C in 5588 flashes was 631 ms. The performance of the algorithm (vs. human judgement) was checked on 100 flashes. At best, the reported algorithm is "correct" 80% of the time, where correct means that multiple stations agree with each other and with a human on both the presence and duration of CC. Of the 100 flashes that were validated against human judgement, 62% were hybrid. Automated analysis detects the first but misses the second return stroke in many cases where the second return stroke is followed by long CC. This problem is also present in human interpretation of field change records.

Evaluation of the Performance Characteristics of the CGLSS and NLDN Systems Based on Two Years of Ground-Truth Data from Launch Complex 39B, Kennedy Space Center, Florida

NASA Technical Reports Server (NTRS)

Mata, Carlos T.; Hill, Jonathan D.; Mata, Angel G.; Cummins, Kenneth L.

2014-01-01

From May 2011 through July 2013, the lightning instrumentation at Launch Complex 39B (LC39B) at the Kennedy Space Center, Florida, has obtained high-speed video records and field change waveforms (dE/dt and three-axis dH/dt) for 54 negative polarity return strokes whose strike termination locations and times are known with accuracy of the order of 10 m or less and 1 µs, respectively. A total of 18 strokes terminated directly to the LC39B lighting protection system (LPS), which contains three 181 m towers in a triangular configuration, an overhead catenary wire system on insulating masts, and nine down conductors. An additional 9 strokes terminated on the 106 m lightning protection mast of Launch Complex 39A (LC39A), which is located about 2.7 km southeast of LC39B. The remaining 27 return strokes struck either on the ground or attached to low-elevation grounded objects within about 500 m of the LC39B LPS. Leader/return stroke sequences were imaged at 3200 frames/sec by a network of six Phantom V310 high-speed video cameras. Each of the three towers on LC39B had two high-speed cameras installed at the 147 m level with overlapping fields of view of the center of the pad. The locations of the strike points of 54 return strokes have been compared to time-correlated reports of the Cloud-to-Ground Lightning Surveillance System (CGLSS) and the National Lightning Detection Network (NLDN), and the results of this comparison will be presented and discussed.

X-ray emission from upward initiated lightning at Gaisberg tower

NASA Astrophysics Data System (ADS)

Hettiarachchi, P.; Cooray, G. V.; Diendorfer, G.; Pichler, H.; Dwyer, J. R.; Rassoul, H.

2016-12-01

We report the occurrence of X-rays at ground level due to cloud to ground flashes of upward initiated lightning from Gaisberg tower in Austria which is located at a 1300m altitude. This is the first time that the X-rays from upward lightning from a tower top located in high altitude is observed. Measurement was carried out using scintillation detectors installed close to the tower top. X-rays were recorded in three subsequent strokes of two flashes out of the total 15 flashes recorded in the system in the period December 2014 to July 2015. In contrast to the observations from downward natural or triggered lightning, X-rays were observed only within 10 µs prior to the subsequent return stroke. This shows that X-rays were emitted when the dart leader is in the vicinity of the tower top and hence during the most intense phase of the dart leader. Both the detected energy and the fluence of X-rays are far lower compared to X-rays from downward natural or rocket triggered lightning. The X-ray waveforms together with current and electric field measurements is presented and comparison of this result to previous ground level observations of X-rays from natural and triggered lightning is discussed.

Remote sensing and modeling of lightning caused long recovery events within the lower ionosphere using VLF/LF radio wave propagation

NASA Astrophysics Data System (ADS)

Schmitter, E. D.

2014-11-01

On the 4 November 2012 at 3:04:27 UT a strong lightning in the midst of the North Sea affected the propagation conditions of VLF/LF transmitter radio signals from NRK (Iceland, 37.5 kHz) and GBZ (UK, 19.58 kHz) received at 5246° N 8° E (NW Germany). The amplitude and phase dips show a recovery time of 6-12 min pointing to a LOng Recovery Early VLF (LORE) event. Clear assignment of the causative return stroke in space and time was possible with data from the WWLLN (Worldwide Lightning Location Network). Based on a return stroke current model the electric field is calculated and an excess electron density distribution which decays over time in the lower ionosphere is derived. Ionization, attachment and recombination processes are modeled in detail. Entering the electron density distribution in VLF/LF radio wave propagation calculations using the LWPC (Long Wavelength Propagation Capability) code allows to model the VLF/LF amplitude and phase behavior by adjusting the return stroke current moment. The results endorse and quantify the conception of lower ionosphere EMP heating by strong - but not necessarily extremely strong - return strokes of both polarities.

Factors Contributing to Patient Satisfaction with Rehabilitation Following Stroke.

ERIC Educational Resources Information Center

Clark, M. S.; Smith, D. S.

1998-01-01

A study that investigated the satisfaction of 60 Australian stroke survivors with their rehabilitative progress over 12 months found satisfaction with progress improved with time and was influenced by the return to previous lifestyle activities, depression, family functioning, understanding of stroke, and clarity of expectations on admission to…

Reliability in the parameterization of the functional reach test in elderly stroke patients: a pilot study.

PubMed

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

2014-01-01

Postural instability is one of the major complications found in stroke survivors. Parameterising the functional reach test (FRT) could be useful in clinical practice and basic research. To analyse the reliability, sensitivity, and specificity in the FRT parameterisation using inertial sensors for recording kinematic variables in patients who have suffered a stroke. Cross-sectional study. While performing FRT, two inertial sensors were placed on the patient's back (lumbar and trunk). Five subjects over 65 who suffer from a stroke. FRT measures, lumbosacral/thoracic maximum angular displacement, maximum time of lumbosacral/thoracic angular displacement, time return initial position, and total time. Speed and acceleration of the movements were calculated indirectly. FRT measure is  12.75±2.06 cm. Intrasubject reliability values range from 0.829 (time to return initial position (lumbar sensor)) to 0.891 (lumbosacral maximum angular displacement). Intersubject reliability values range from 0.821 (time to return initial position (lumbar sensor)) to 0.883 (lumbosacral maximum angular displacement). FRT's reliability was 0.987 (0.983-0.992) and 0.983 (0.979-0.989) intersubject and intrasubject, respectively. The main conclusion could be that the inertial sensors are a tool with excellent reliability and validity in the parameterization of the FRT in people who have had a stroke.

Influence of channel base current and varying return stroke speed on the calculated fields of three important return stroke models

NASA Technical Reports Server (NTRS)

Thottappillil, Rajeev; Uman, Martin A.; Diendorfer, Gerhard

1991-01-01

Compared here are the calculated fields of the Traveling Current Source (TCS), Modified Transmission Line (MTL), and the Diendorfer-Uman (DU) models with a channel base current assumed in Nucci et al. on the one hand and with the channel base current assumed in Diendorfer and Uman on the other hand. The characteristics of the field wave shapes are shown to be very sensitive to the channel base current, especially the field zero crossing at 100 km for the TCS and DU models, and the magnetic hump after the initial peak at close range for the TCS models. Also, the DU model is theoretically extended to include any arbitrarily varying return stroke speed with height. A brief discussion is presented on the effects of an exponentially decreasing speed with height on the calculated fields for the TCS, MTL, and DU models.

Length estimations of presumed upward connecting leaders in lightning flashes to flat water and flat ground

NASA Astrophysics Data System (ADS)

Stolzenburg, Maribeth; Marshall, Thomas C.; Karunarathne, Sumedhe; Orville, Richard E.

2018-10-01

Using video data recorded at 50,000 frames per second for nearby negative lightning flashes, estimates are derived for the length of positive upward connecting leaders (UCLs) that presumably formed prior to new ground attachments. Return strokes were 1.7 to 7.8 km distant, yielding image resolutions of 4.25 to 19.5 m. No UCLs are imaged in these data, indicating those features were too transient or too dim compared to other lightning processes that are imaged at these resolutions. Upper bound lengths for 17 presumed UCLs are determined from the height above flat ground or water of the successful stepped leader tip in the image immediately prior to (within 20 μs before) the return stroke. Better estimates of maximum UCL lengths are determined using the downward stepped leader tip's speed of advance and the estimated return stroke time within its first frame. For 17 strokes, the upper bound length of the possible UCL averages 31.6 m and ranges from 11.3 to 50.3 m. Among the close strokes (those with spatial resolution <8 m per pixel), the five which connected to water (salt water lagoon) have UCL upper bound estimates averaging significantly shorter (24.1 m) than the average for the three close strokes which connected to land (36.9 m). The better estimates of maximum UCL lengths for the eight close strokes average 20.2 m, with slightly shorter average of 18.3 m for the five that connected to water. All the better estimates of UCL maximum lengths are <38 m in this dataset

Four-year follow-up of transient ischemic attacks, strokes, and mimics: a retrospective transient ischemic attack clinic cohort study.

PubMed

Dutta, Dipankar; Bowen, Emily; Foy, Chris

2015-05-01

There is limited information on outcomes from rapid access transient ischemic attack (TIA) clinics. We present 4-year outcomes of TIAs, strokes, and mimics from a UK TIA clinic database. All patients referred between April 2010 and May 2012 were retrospectively identified and outcomes determined. End points were stroke, myocardial infarction, any vascular event (TIA, stroke, or myocardial infarction), and all-cause death. Data were analyzed by survival analysis. Of 1067 patients, 31.6% were TIAs, 18% strokes, and 50.4% mimics. Median assessment time was 4.5 days from onset and follow-up was for 34.9 months. Subsequent strokes occurred in 7.1% of patients with TIA, 10.9% of patients with stroke, and 2.0% of mimics at the end of follow-up. Stroke risk at 90 days was 1.3% for patients diagnosed as TIA or stroke. Compared with mimics, hazard ratios for subsequent stroke were 3.88 (1.90-7.91) for TIA and 5.84 (2.81-12.11) for stroke. Hazard ratio for any subsequent vascular event was 2.91 (1.97-4.30) for TIA and 2.83 (1.81-4.41) for stroke. Hazard ratio for death was 1.68 (1.10-2.56) for TIA and 2.19 (1.38-3.46) for stroke. Our results show a lower 90-day stroke incidence after TIA or minor stroke than in earlier studies, suggesting that rapid access daily TIA clinics may be having a significant effect on reducing strokes. © 2015 American Heart Association, Inc.

Socioeconomic disparities in work performance following mild stroke.

PubMed

Brey, Joseph K; Wolf, Timothy J

2015-01-01

The purpose of this study was to investigate the relationships among the factors that influence return to work for young individuals with mild stroke from different socioeconomic backgrounds. Prospective cohort study of working adults with mild stroke (N = 21). Participants completed an assessment battery of cognitive, work environment and work performance measures at approximately 3 weeks and 7 months post mild stroke. Individuals were placed in "skilled" and "unskilled" worker categories based on the Hollingshead Index. Unskilled workers had significantly poorer scores on the majority of the cognitive assessments. Unskilled workers also perceived less social support (p = 0.017) and autonomy (p = 0.049) in work responsibilities than individuals in the skilled worker group and also reported significantly poorer work productivity due to stroke than those in the skilled group (p = 0.015). Individuals from low socioeconomic backgrounds have more difficulty returning to work following mild stroke than individuals from higher socioeconomic backgrounds. Future work is needed to identify factors that can increase long-term work success and quality of work performance following a mild stroke that specifically targets the needs of individuals who have a lower socioeconomic status.

Lightning Step Leader and Return Stroke Spectra at 100,000 fps

NASA Astrophysics Data System (ADS)

Harley, J.; McHarg, M.; Stenbaek-Nielsen, H. C.; Haaland, R. K.; Sonnenfeld, R.; Edens, H. E.; Cummer, S.; Lapierre, J. L.; Maddocks, S.

2017-12-01

A fundamental understanding of lightning can be inferred from the spectral emissions resulting from the leader and return stroke channels. We examine events recorded at 00:58:07 on 19 July 2015 and 06:44:24 on 23 July 2017, both at Langmuir Laboratory. Analysis of both events is supplemented by data from the Lightning Mapping Array at Langmuir. The 00:58:07 event spectra was recorded using a 100 line per mm grating in front of a Phantom V2010 camera with an 85mm (9o FOV) Nikon lens recording at 100,000 frames per second. Coarse resolution spectra (approximately 5 nm resolution) are produced from approximately 400 nm to 800 nm for each frame. We analyze several nitrogen and oxygen lines to understand step leader temperature behavior between cloud and ground. The 06:44:24 event spectra was recorded using a 300 line per mm grating (approximately 1.5 nm resolution) in front of a Phantom V2010 camera with an 50mm (32o FOV) Nikon lens also recording at 100,000 frames per second. Two ionized atomic nitrogen lines at 502 nm and 569 nm appear upon attachment and disappear as the return stroke travels from ground to cloud in approximately 5 frames. We analyze these lines to understand initial return stroke temperature and species behavior.

Effects of professional rehabilitation training on the recovery of neurological function in young stroke patients

PubMed Central

Li, Chao-jin-zi; Du, Xiao-xia; Yang, Kun; Song, Lu-ping; Li, Peng-kun; Wang, Qiang; Sun, Rong; Lin, Xiao-ling; Lu, Hong-yu; Zhang, Tong

2016-01-01

Young stroke patients have a strong desire to return to the society, but few studies have been conducted on their rehabilitation training items, intensity, and prognosis. We analyzed clinical data of young and middle-aged/older stroke patients hospitalized in the Department of Neurological Rehabilitation, China Rehabilitation Research Center, Capital Medical University, China from February 2014 to May 2015. Results demonstrated that hemorrhagic stroke (59.6%) was the primary stroke type found in the young group, while ischemic stroke (60.0%) was the main type detected in the middle-aged/older group. Compared with older stroke patients, education level and incidence of hyperhomocysteinemia were higher in younger stroke patients, whereas, incidences of hypertension, diabetes, and heart disease were lower. The average length of hospital stay was longer in the young group than in the middle-aged/older group. The main risk factors observed in the young stroke patients were hypertension, drinking, smoking, hyperlipidemia, hyperhomocysteinemia, diabetes, previous history of stroke, and heart disease. The most accepted rehabilitation program consisted of physiotherapy, occupational therapy, speech therapy, acupuncture and moxibustion. Average rehabilitation training time was 2.5 hours/day. Barthel Index and modified Rankin Scale scores were increased at discharge. Six months after discharge, the degree of occupational and economic satisfaction declined, and there were no changes in family life satisfaction. The degrees of other life satisfaction (such as friendship) improved. The degree of disability and functional status improved significantly in young stroke patients after professional rehabilitation, but the number of patients who returned to society within 6 months after stroke was still small. PMID:28123417

Split-Step Timing of Professional and Junior Tennis Players

PubMed Central

Leskosek, Bojan; Filipcic, Tjasa

2017-01-01

Abstract The purpose of the study was to determine the timing of a split-step in three categories of tennis players in four groups of strokes. Subjects were divided into three groups: male and female junior, and male professional tennis players. During two tournaments, all matches were recorded with two fixed video cameras. For every stroke, the timing of the split-step between the opponent’s impact point when hitting the ball and the player’s split-step was measured. A two-way analysis of variance (ANOVA) was used to determine the differences between groups of strokes, players and the interaction Player x Stroke Group. A Tukey post-hoc test was employed to determine specific differences. The results revealed differences between players in detecting the opponent’s movement, stroke and ball flight, which were reflected in different split-step timings. Each tennis player has his/her own timing mechanism which they adapt to various game situations. Response times differ significantly depending on the game situation. On average, they are the lowest in the serve, and then gradually rise from the return of the serve to baseline game, reaching the highest values in specific game situations. Players react faster in the first serve than in the second one and in the return of the serve, the response times are lower after the return of the second serve PMID:28210342

Computed tomography identifies patients at high risk for stroke after transient ischemic attack/nondisabling stroke: prospective, multicenter cohort study.

PubMed

Wasserman, Jason K; Perry, Jeffrey J; Sivilotti, Marco L A; Sutherland, Jane; Worster, Andrew; Émond, Marcel; Jin, Albert Y; Oczkowski, Wieslaw J; Sahlas, Demetrios J; Murray, Heather; MacKey, Ariane; Verreault, Steve; Wells, George A; Dowlatshahi, Dar; Stotts, Grant; Stiell, Ian G; Sharma, Mukul

2015-01-01

Ischemia on computed tomography (CT) is associated with subsequent stroke after transient ischemic attack. This study assessed CT findings of acute ischemia, chronic ischemia, or microangiopathy for predicting subsequent stroke after transient ischemic attack. This prospective cohort study enrolled patients with transient ischemic attack or nondisabling stroke that had CT scanning within 24 hours. Primary outcome was subsequent stroke within 90 days. Secondary outcomes were stroke at ≤2 or >2 days. CT findings were classified as ischemia present or absent and acute or chronic or microangiopathy. Analysis used Fisher exact test and multivariate logistic regression. A total of 2028 patients were included; 814 had ischemic changes on CT. Subsequent stroke rate was 3.4% at 90 days and 1.5% at ≤2 days. Stroke risk was greater if baseline CT showed acute ischemia alone (10.6%; P=0.002), acute+chronic ischemia (17.4%; P=0.007), acute ischemia+microangiopathy (17.6%; P=0.019), or acute+chronic ischemia+microangiopathy (25.0%; P=0.029). Logistic regression found acute ischemia alone (odds ratio [OR], 2.61; 95% confidence interval [CI[, 1.22-5.57), acute+chronic ischemia (OR, 5.35; 95% CI, 1.71-16.70), acute ischemia+microangiopathy (OR, 4.90; 95% CI, 1.33-18.07), or acute+chronic ischemia+microangiopathy (OR, 8.04; 95% CI, 1.52-42.63) was associated with a greater risk at 90 days, whereas acute+chronic ischemia (OR, 10.78; 95% CI, 2.93-36.68), acute ischemia+microangiopathy (OR, 8.90; 95% CI, 1.90-41.60), and acute+chronic ischemia+microangiopathy (OR, 23.66; 95% CI, 4.34-129.03) had greater risk at ≤2 days. Only acute ischemia (OR, 2.70; 95% CI, 1.01-7.18; P=0.047) was associated with a greater risk at >2 days. In patients with transient ischemic attack/nondisabling stroke, CT evidence of acute ischemia alone or acute ischemia with chronic ischemia or microangiopathy was associated with increased subsequent stroke risk within 90 days. © 2014 American Heart Association, Inc.

Navigation of the autonomous vehicle reverse movement

NASA Astrophysics Data System (ADS)

Rachkov, M.; Petukhov, S.

2018-02-01

The paper presents a mathematical formulation of the vehicle reverse motion along a multi-link polygonal trajectory consisting of rectilinear segments interconnected by nodal points. Relevance of the problem is caused by the need to solve a number of tasks: to save the vehicle in the event of а communication break by returning along the trajectory already passed, to avoid a turn on the ground in constrained obstacles or dangerous conditions, or a partial return stroke for the subsequent bypass of the obstacle and continuation of the forward movement. The method of navigation with direct movement assumes that the reverse path is elaborated by using landmarks. To measure landmarks on board, a block of cameras is placed on a vehicle controlled by the operator through the radio channel. Errors in estimating deviation from the nominal trajectory of motion are determined using the multidimensional correlation analysis apparatus based on the dynamics of a lateral deviation error and a vehicle speed error. The result of the experiment showed a relatively high accuracy in determining the state vector that provides the vehicle reverse motion relative to the reference trajectory with a practically acceptable error while returning to the start point.

[Good practice in occupational health services--Certification of stroke as an accident at work. Need for secondary prevention in people returning to work after acute cerebrovascular events].

PubMed

Marcinkiewicz, Andrzej; Walusiak-Skorupa, Jolanta

2015-01-01

The classification of an acute vascular episode, both heart infarct and stroke, as an accident at work poses difficulties not only for post accidental teams, but also to occupational health professionals, experts and judges at labor and social insurance courts. This article presents the case of a 41-year-old office worker, whose job involved client services. While attending a very aggressive customer she developed solid stress that resulted in symptoms of the central nervous system (headache, speech disturbances). During her hospitalisation at the neurological unit ischemic stroke with transient mixed type aphasia was diagnosed. Magnetic resonance imaging (MRI) scan of the head revealed subacute ischemia. After an analysis of the accident circumstances, the employer's post accidental team decided that ischemic stroke had been an accident at work, because it was a sudden incident due to an external cause inducing work-related traumatic stroke. As a primary cause tough stress and emotional strain due to the situation developed while attending the customer were acknowledged. During control medical check up after 5 months the patient was found to be fit for work, so she could return to work. However, it should be noted that such a check up examination of subjects returning to work after stroke must be holistic, including the evaluation of job predispositions and health education aimed at secondary prevention of heart and vascular diseases with special reference to their risk factors. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

First images of thunder: Acoustic imaging of triggered lightning

NASA Astrophysics Data System (ADS)

Dayeh, M. A.; Evans, N. D.; Fuselier, S. A.; Trevino, J.; Ramaekers, J.; Dwyer, J. R.; Lucia, R.; Rassoul, H. K.; Kotovsky, D. A.; Jordan, D. M.; Uman, M. A.

2015-07-01

An acoustic camera comprising a linear microphone array is used to image the thunder signature of triggered lightning. Measurements were taken at the International Center for Lightning Research and Testing in Camp Blanding, FL, during the summer of 2014. The array was positioned in an end-fire orientation thus enabling the peak acoustic reception pattern to be steered vertically with a frequency-dependent spatial resolution. On 14 July 2014, a lightning event with nine return strokes was successfully triggered. We present the first acoustic images of individual return strokes at high frequencies (>1 kHz) and compare the acoustically inferred profile with optical images. We find (i) a strong correlation between the return stroke peak current and the radiated acoustic pressure and (ii) an acoustic signature from an M component current pulse with an unusual fast rise time. These results show that acoustic imaging enables clear identification and quantification of thunder sources as a function of lightning channel altitude.

Attributing heart attack and stroke to "Old Age": Implications for subsequent health outcomes among older adults.

PubMed

Stewart, Tara L; Chipperfield, Judith G; Perry, Raymond P; Hamm, Jeremy M

2016-01-01

This study assessed the extent to which older adults attribute a recent heart attack/stroke to "old age," and examined consequences for subsequent lifestyle behavior and health-care service utilization. Community-dwelling adults (N = 57, ages 73-98 years) were interviewed about their heart attack/stroke, and an objective health registry provided data on health-care utilization over a 3-year period. Endorsement of "old age" as a cause of heart attack/stroke negatively predicted lifestyle behavior change, and positively predicted frequency of physician visits and likelihood of hospitalization over the subsequent 3 years. Findings suggest the importance of considering "old age" attributions in the context of cardiovascular health events. © The Author(s) 2014.

Retinal microvascular changes and subsequent vascular events after ischemic stroke.

PubMed

De Silva, D A; Manzano, J J F; Liu, E Y; Woon, F-P; Wong, W-X; Chang, H-M; Chen, C; Lindley, R I; Wang, J J; Mitchell, P; Wong, T-Y; Wong, M-C

2011-08-30

Retinal microvasculature changes are associated with vascular events including stroke in healthy populations. It is not known whether retinal microvascular changes predict recurrent vascular events after ischemic stroke. We examined the relationship between retinal microvascular signs and subsequent vascular events in a prospective cohort of 652 acute ischemic stroke patients admitted to a tertiary hospital in Singapore from 2005 to 2007. Retinal photographs taken within 1 week of stroke onset were assessed in a masked manner for quantitative and qualitative measures. Follow-up data over 2-4 years were obtained by standardized telephone interview and then were verified from medical records. Predictors of recurrent vascular events (cerebrovascular, coronary, vascular death, and composite vascular events) were determined using Cox regression models. Follow-up data over a median of 29 months were obtained for 89% (652 patients) of the cohort. After adjustment for covariates including traditional risk factors and index stroke etiology, patients with severe arteriovenous nicking (AVN) were more likely to have a recurrent cerebrovascular event (hazard ratio [HR] 2.28, 95% confidence interval [CI] 1.20-4.33) compared with those without AVN. Patients with severe focal arteriolar narrowing (FAN) were more likely to have a recurrent cerebrovascular event (HR 2.75, 95% CI 1.14-6.63) or subsequent composite vascular event (HR 2.77, 95% CI 1.31-5.86) compared to those without FAN. Retinal microvascular changes predicted subsequent vascular events after ischemic stroke, independent of traditional risk factors and stroke subtype. Thus, retinal imaging has a potential role in predicting the risk of recurrent vascular events after ischemic stroke and in understanding novel vascular risk factors.

Three unusual strokes in a triggered lightning flash

NASA Technical Reports Server (NTRS)

Idone, V. P.; Orville, R. E.

1984-01-01

Time-resolved photographic records of three strokes of a triggered lightning flash are examined. These strokes exhibit several examples of novel behavior that include (1) the abrupt transformation of dart leaders to stepped leaders and (2) the partial 'reflection' of dart leader luminosity back up the channel. Both phenomena are associated with an apparent discontinuity in channel characteristics between the natural and artificial (wire) sections of the channel. We estimate the ratio of characteristic impedances for these sections to have an upper bound of about a factor of 3. Analysis of one of the dart leader 'reflections' yields a propagation speed of 9.6 x 10 to the 7th m/s whereas the dart leader and return stroke speeds (two-dimensional) over the same channel section are 1.7 x 10 to the 7th and 13 x 10 to the seventh m/s, respectively. Also, one of the return strokes reveals the occurrence of two distinct waves of luminosity that are separated by only 5 microns and that travel up nearly identical channels that differ only in the channel terminus.

Depression and young age impact on hip fracture subsequent to stroke: A population-based cohort study.

PubMed

Yeh, Hui-Fang; Hsu, Yao-Chun; Clinciu, Daniel L; Tung, Heng-Hsin; Yen, Yung-Chieh; Kuo, Hung-Chang

2018-06-03

The purpose of this study is to identify whether depression and other associated factors in stroke are related to subsequent hip fracture. There are very few studies that focus on depression and demographic impact on subsequent hip fracture after a stroke. This a retrospective cohort study design. The Taiwan Longitudinal Health Insurance Database between 1997 and 2010 was used. Two stroke patient cohorts were analysed: (1) depression within 1 year after newly diagnosed strokes; (2) without depression within 1 year after newly diagnosed strokes. Demographic characteristics, comorbidities, and hip fracture were compared using the Fine and Gray regression model for subdistribution hazard ratios. Patients with depression showed a higher risk of hip fracture (95% CI, 0.99-1.66). Depression was associated with increased risk of hip fracture for patients below 50 years old (95% CI, 1.45-7.34). Comorbidities and gender showed no significant correlation with hip fracture risk in the depressed or nondepressed groups. Poststroke depression was a significant contributor to hip fracture in patients who suffered strokes and had more negative impact on the younger population, regardless of the gender and presence of comorbidities. © 2018 John Wiley & Sons Australia, Ltd.

[Impairment and disability in patients with a severe ischemic cerebral infarction at admission to the rehabilitation center and six months after stroke].

PubMed

Prevo, A J; Dijkman, M M; Le Fèvre, F A

1998-03-21

Evaluation of impairment and disability in stroke patients with a severe cortical infarction at admission as well as six months after the stroke. Prospective and descriptive study. Rehabilitation Centre Heliomare, Wijk aan Zee, the Netherlands. Between 1 January 1987 en 31 May 1992 stroke patients were admitted to the rehabilitation centre with a severe, first ever, cortical infarction without any comorbidity. The patients were dependent in activities of daily living and wheel-chair-bound. Motor and neuropsychological impairment and disability were evaluated at admission to the rehabilitation centre as well as six months after the stroke. Return to home and length of stay were evaluated. 43 patients were included. Recovery of arm and hand function was very poor (there was complete paresis at admission in 33 patients (77%) and six months after the CVA in 25 patients (58%)); recovery of the affected leg was reasonable (complete paresis in 10 (23%) and 0 patients, respectively). Cognitive deficits diminished in severity, but remained noticeable in three-quarters of the patients. Independent walking was achieved by 30 patients (70%), independence in personal activities of daily living by 32 patients (74%) and returning home by 36 patients (84%). The mean hospital stay was 26 weeks (SD: 9.26; range: 11-30). Prognosis of personal independence and returning home after a severe cortical infarction was rather good despite poor recovery of motor and cognitive impairment.

The influence of tortuosity on the spectrum of radiation from lightning return strokes

NASA Technical Reports Server (NTRS)

Levine, D. M.

1978-01-01

An investigation was made of the influence of tortuosity on the spectrum of radiation from lightning return strokes. The shape of the spectrum obtained by including effects of tortuosity was in keeping with data: The spectrum had a peak in the correct frequency regime followed by an initial decrease as the inverse of frequency. This spectrum was in better agreement with data than the spectrum predicted by the same model without tortuosity (i.e. the long straight channel), which decays at a rate proportional to 1/v squared.

A Unified Model of Cloud-to-Ground Lightning Stroke

NASA Astrophysics Data System (ADS)

Nag, A.; Rakov, V. A.

2014-12-01

The first stroke in a cloud-to-ground lightning discharge is thought to follow (or be initiated by) the preliminary breakdown process which often produces a train of relatively large microsecond-scale electric field pulses. This process is poorly understood and rarely modeled. Each lightning stroke is composed of a downward leader process and an upward return-stroke process, which are usually modeled separately. We present a unified engineering model for computing the electric field produced by a sequence of preliminary breakdown, stepped leader, and return stroke processes, serving to transport negative charge to ground. We assume that a negatively-charged channel extends downward in a stepped fashion through the relatively-high-field region between the main negative and lower positive charge centers and then through the relatively-low-field region below the lower positive charge center. A relatively-high-field region is also assumed to exist near ground. The preliminary breakdown pulse train is assumed to be generated when the negatively-charged channel interacts with the lower positive charge region. At each step, an equivalent current source is activated at the lower extremity of the channel, resulting in a step current wave that propagates upward along the channel. The leader deposits net negative charge onto the channel. Once the stepped leader attaches to ground (upward connecting leader is presently neglected), an upward-propagating return stroke is initiated, which neutralizes the charge deposited by the leader along the channel. We examine the effect of various model parameters, such as step length and current propagation speed, on model-predicted electric fields. We also compare the computed fields with pertinent measurements available in the literature.

Causes and Severity of Ischemic Stroke in Patients with Symptomatic Intracranial Arterial Stenosis

PubMed Central

Famakin, Bolanle M; Chimowitz, Marc I; Lynn, Michael J; Stern, Barney J; George, Mary G.

2009-01-01

Background and purpose There are limited data on the causes and severity of subsequent stroke in patients presenting initially with TIA or stroke attributed to intracranial arterial stenosis. Methods We evaluated the location, type (lacunar vs. non-lacunar), cause, and severity of stroke in patients who had an ischemic stroke endpoint in the Warfarin Aspirin Symptomatic Intracranial Disease (WASID) trial. Results Of the 569 patients enrolled in the WASID trial, 106 patients (18.6%) had an ischemic stroke during a mean follow-up of 1.8 years. Stroke occurred in the territory of the symptomatic artery in 77 (73%) of 106 patients. Among the 77 strokes in the territory, 70 (91%) were non-lacunar and 34 (44%) were disabling. Stroke out of the territory of the symptomatic artery occurred in 29 (27%) of 106 patients. Among these 29 strokes, 24 (83%) were non-lacunar, 14 (48%) were due to previously asymptomatic intracranial stenosis, and 9 (31%) were disabling. Conclusions Most subsequent strokes in patients with symptomatic intracranial artery stenosis are in the same territory and non-lacunar, and nearly half of the strokes in the territory are disabling. The most commonly identified cause of stroke out of the territory was a previously asymptomatic intracranial stenosis. Penetrating artery disease was responsible for a low number of strokes. PMID:19407228

Characterization of vertical electric fields 500 m and 30 m from triggered lightning

NASA Astrophysics Data System (ADS)

Rubenstein, M.; Rachidi, F.; Uman, M. A.; Thottappillil, R.; Rakov, V. A.; Nucci, C. A.

1995-05-01

Vertical electric field waveforms of leader-return stroke sequences measured 500 m and 30 m from rocket-triggered lightning are presented. The 500-m data were recorded during the summer of 1986, the 30-m data during the summer of 1991, both at the NASA Kennedy Space Center, Florida. The 40 leader-return stroke field waveforms at 500 m and the 8 waveforms at 30 m all appear as asymmetrical V-shaped pulses, the bottom of the V being associated with the transition from the leader to the return stroke. Only two waveforms at 30 m were suitable for quantitative analysis. The widths of the V at half of peak value for these are 1.8 and 5.0 μs, while for the 500-m data they are 1 to 2 orders of magnitude greater, with a median value of 100 μs. Applying a widely used and simple leader model to the measured leader electric fields at 500 m, we infer, for the bottom kilometer or so of the leader channel, leader speeds between 2×106 and 2×107 m/s and leader charges per unit length of 0.02×10-3 to 0.08×10-3 C/m. From the two measured leader electric field changes at 30 m we infer, using the same leader model, for the bottom 100 meters or so of the leader channel, speeds of 3×107 and 1×107 m/s (the corresponding measured waveform half widths are 1.8 μs and 5.0 μs) and charges per unit length of 0.14×10-3 and 0.02×10-3 C/m (the corresponding measured leader field changes are 81 kV/m and 12 kV/m). The corresponding measured return stroke peak currents for the above two cases are 40 kA and 7 kA, respectively. A positive correlation is observed between the magnitude of the leader field change at 500 m and the ensuing return stroke current peak.

Barriers and facilitators of return to work for individuals with strokes: perspectives of the stroke survivor, vocational specialist, and employer.

PubMed

Culler, Kathleen H; Wang, Ying-Chih; Byers, Katherine; Trierweiler, Robert

2011-01-01

The purpose of this study was to identify factors that facilitated or acted as a barrier to return to work (RTW) for stroke survivors. We applied 3 approaches to identify the factors. First, we conducted qualitative interviews with 10 stroke survivors about their RTW experience post stroke. Second, we surveyed 21 vocational specialists about barriers and facilitators of RTW based on their clinical practice. Last, we interviewed 7 employers who had experience in interviewing individuals with disabilities or had the authority to make hiring decisions. Descriptions of barriers and facilitators to RTW from these 3 perspectives were illustrated. Identified components were mapped based on the ICF framework. From stroke survivors' perspectives, factors affecting employment after stroke include neurological (motor, cognition, communication), social, personal, and environmental factors. Vocational specialists described similar barriers and facilitators of RTW as the stroke survivors but emphasized personal factors such as flexibility and being realistic in vocational goals. The employers explained that the candidate's disability plays no role in the hiring process and indicated that all applicants must meet the essential job requirements. Some employers described the benefits of having the support of vocational rehabilitation staff and being able to interact with the vocational rehabilitation specialists during the hiring process. The interaction allows the employer to gather initial information (consented to by the job applicant) about the applicants from the vocational rehabilitation service and to be educated about any specific needs related to the applicant's medical issues.

Electrification in winter storms and the analysis of thunderstorm overflight data

NASA Technical Reports Server (NTRS)

Brook, Marx

1993-01-01

We have been focusing our study of electrification in winter storms on the lightning initiation process, making inferences about the magnitude of the electric fields from the initial pulses associated with breakdown, i.e., with the formation of the initial streamers. The essence of the most significant finding is as follows: (1) initial breakdown radiation pulses from stepped leaders prior to the first return stroke are very large, reaching values of 20-30 Volts/meter, comparable to return stroke radiation; and (2) the duration of the stepped leader, from the initial detectable radiation pulse to the return stroke onset, is very-short-ranging from a minimum 1.5 ms to a maximum of 4.5 ms. This past summer (June-August of 1991) we participated in the CAPE program at the Kennedy Space Center in order to acquire data on stepped leaders in summer storms with the same equipment used to get the winter storm data. We discovered that the vigorous leaders seen in winter so frequently were present in summer storms, although not as large in amplitude and certainly not as frequent.

Experiences of the return to work process after stroke while participating in a person-centred rehabilitation programme.

PubMed

Öst Nilsson, Annika; Eriksson, Gunilla; Johansson, Ulla; Hellman, Therese

2017-09-01

In Sweden, less than 50% of those getting stroke in working age return to work (RTW). Effective rehabilitation programmes need to be developed and therapeutic aspects understood. To explore and describe how persons with stroke experience their RTW process while participating in a person-centred rehabilitation programme focusing on RTW. Seven persons with mild or moderate stroke were interviewed twice during the intervention in the vocational training phase using semi-structured interviews. Data were analysed using grounded theory. Having a coordinator by their side gave support and guidance during the RTW process. Knowledge of stroke, strategies and a straightforward communication created a structure for the RTW process. Expressing one's own wishes increased opportunities to influence and decide which path to follow in order to reach the goal. Straightforward, open and recurring communication facilitated the possibility to adapt to the situation. These aspects increased insight and awareness which facilitated the RTW process. The findings indicate that a precondition for a fruitful RTW process was that suitable platforms at work were created in which the actors involved could cooperate. This knowledge might also be valuable in the RTW process for people with other diagnosis.

Application of the Lienard-Wiechert solution to a lightning return stroke model

NASA Technical Reports Server (NTRS)

Meneghini, R.

1983-01-01

The electric and magnetic fields associated with the lightning return stroke are expressed as a convolution of the current waveform shape and the fields generated by a moving charge of amplitude one (i.e., the Lienard-Wiechert solution for a unit charge). The representation can be used to compute the fields produced by a current waveform of non-uniform velocity that propagates along a filament of arbitrary, but finite, curvature. To study numerically the effects of linear charge acceleration and channel curvature two simple channel models are used: the linear and the hyperbolic.

Application of the Lienard-Wiechert solution to a lightning return stroke model

NASA Technical Reports Server (NTRS)

Meneghini, R.

1984-01-01

The electric and magnetic fields associated with the lightning return stroke are expressed as a convolution of the current waveform shape and the fields generated by a moving charge of amplitude one (i.e., the Lienard-Wiechert solution for a unit charge). The representation can be used to compute the fields produced by a current waveform of non-uniform velocity that propagates along a filament of arbitrary, but finite, curvature. To study numerically the effects of linear charge acceleration and channel curvature two simple channel models are used: the linear and the hyperbolic.

On the electromagnetic fields, Poynting vector, and peak power radiated by lightning return strokes

NASA Technical Reports Server (NTRS)

Krider, E. P.

1992-01-01

The initial radiation fields, Poynting vector, and total electromagnetic power that a vertical return stroke radiates into the upper half space have been computed when the speed of the stroke, nu, is a significant fraction of the speed of light, c, assuming that at large distances and early times the source is an infinitesimal dipole. The initial current is also assumed to satisfy the transmission-line model with a constant nu and to be perpendicular to an infinite, perfectly conducting ground. The effect of a large nu is to increase the radiation fields by a factor of (1-beta-sq cos-sq theta) exp -1, where beta = nu/c and theta is measured from the vertical, and the Poynting vector by a factor of (1-beta-sq cos-sq theta) exp -2.

Athletics, minor trauma, and pediatric arterial ischemic stroke.

PubMed

Sepelyak, Kathryn; Gailloud, Philippe; Jordan, Lori C

2010-05-01

Pediatric arterial ischemic stroke may occur as the result of trivial head or neck trauma sustained during a sports activity. We describe three cases of sports-related stroke in previously healthy school-age children and discuss acute and long-term stroke care. Possible mechanisms of sports-related stroke are addressed, as is evaluation for cause of stroke in children. In one of the reported cases, the child was found to have a vertebral artery dissection as the cause of his stroke, but no definitive cause of stroke was identified in the other two cases despite extensive evaluation. The advisability and timing of returning to athletic activities after stroke is also discussed. Many children with sports-related stroke are initially seen by a sports trainer, a pediatrician, or an ER physician. Thus, it is particularly important that these professionals are aware of the possibility of ischemic stroke occurring after even mild athletic injury. Childhood stroke may result from injuries sustained during athletic activities and should be considered when a child has acute focal neurologic signs.

Prediction of recovery of motor function after stroke.

PubMed

Stinear, Cathy

2010-12-01

Stroke is a leading cause of disability. The ability to live independently after stroke depends largely on the reduction of motor impairment and the recovery of motor function. Accurate prediction of motor recovery assists rehabilitation planning and supports realistic goal setting by clinicians and patients. Initial impairment is negatively related to degree of recovery, but inter-individual variability makes accurate prediction difficult. Neuroimaging and neurophysiological assessments can be used to measure the extent of stroke damage to the motor system and predict subsequent recovery of function, but these techniques are not yet used routinely. The use of motor impairment scores and neuroimaging has been refined by two recent studies in which these investigations were used at multiple time points early after stroke. Voluntary finger extension and shoulder abduction within 5 days of stroke predicted subsequent recovery of upper-limb function. Diffusion-weighted imaging within 7 days detected the effects of stroke on caudal motor pathways and was predictive of lasting motor impairment. Thus, investigations done soon after stroke had good prognostic value. The potential prognostic value of cortical activation and neural plasticity has been explored for the first time by two recent studies. Functional MRI detected a pattern of cortical activation at the acute stage that was related to subsequent reduction in motor impairment. Transcranial magnetic stimulation enabled measurement of neural plasticity in the primary motor cortex, which was related to subsequent disability. These studies open interesting new lines of enquiry. WHERE NEXT?: The accuracy of prediction might be increased by taking into account the motor system's capacity for functional reorganisation in response to therapy, in addition to the extent of stroke-related damage. Improved prognostic accuracy could also be gained by combining simple tests of motor impairment with neuroimaging, genotyping, and neurophysiological assessment of neural plasticity. The development of algorithms to guide the sequential combinations of these assessments could also further increase accuracy, in addition to improving rehabilitation planning and outcomes. Copyright © 2010 Elsevier Ltd. All rights reserved.

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.

Coincident Observation of Lightning using Spaceborne Spectrophotometer and Ground-Level Electromagnetic Sensors

NASA Technical Reports Server (NTRS)

Adachi, Toru; Cohen, Morris; Li, Jingbo; Cummer, Steve; Blakeslee, Richard; Marshall, THomas; Stolzenberg, Maribeth; Karunarathne, Sumedhe; Hsu, Rue-Ron; Su, Han-Tzong;

The experiences and needs of Chinese-Canadian stroke survivors and family caregivers as they re-integrate into the community.

PubMed

Yeung, Emily H L; Szeto, Amy; Richardson, Denyse; Lai, Suk-han; Lim, Eva; Cameron, Jill I

2015-09-01

Stroke is a leading cause of adult disability and community re-integration is a priority for stroke rehabilitation. In North America, we have a growing population of individuals whose first language is not English. Little is known about the experiences of visible minorities living in North America as they re-integrate into the community post stroke or how these experiences change over time. Specifically, this research aimed to explore the experiences and needs of Chinese stroke survivors and family caregivers as they return to community living using the Timing it Right Framework as a conceptual guide. We recruited Cantonese-speaking stroke survivors and family caregivers from outpatient rehabilitation programmes. Using qualitative interviews conducted in Cantonese or English, we examined their experiences and needs as they return to community living and explored the influence of culture and time on their experiences. The interviews were transcribed and translated, and then analysed using framework analysis. Using framework analysis, we coded the data corresponding to the phases of the Timing it Right framework to determine the influence of time on the themes. We interviewed five Cantonese-speaking stroke survivors and 13 caregivers in 2009. We identified two main themes: (i) Participants' education and support needs change over time and (ii) Chinese resources are needed across care environments. These resources include access to care in their preferred language, traditional Chinese medicine, and Chinese food during their recovery and rehabilitation. To optimise Chinese stroke survivors' and caregivers' community re-integration, healthcare professionals should provide timely and accessible education and be aware of the role of Chinese diet and traditional medicine in stroke survivors' rehabilitation. © 2014 John Wiley & Sons Ltd.

A 21st century investigation of the lightning spectrum

NASA Astrophysics Data System (ADS)

Walker, Thomas Daniel

In the mid 1960s, Martin Uman, Leon Salanave and Richard Orville laid the foundation for lightning spectroscopy. They were among the first to acquire time resolved return stroke spectra and the first to use spectroscopy as a diagnostic technique to characterize physical properties of the lightning channel. Now, almost 50 years later, technology, including CMOS and CCD high speed cameras, volume-phase holographic (VPH) gratings, and triggered lightning, has progressed to the point at which new studies in lightning spectroscopy are needed to verify and extend past measurements. New spectral lines have been discovered in the lightning spectrum as a result of the modern studies, mainly doubly ionized nitrogen lines which had not been observed in the past. The modern technique uses CMOS and CCD cameras with frame rates of up to 1Mfps with exposure down to 0.5mus. The high frame rate paired with camera memory enables a view into the quick high temperature heating period within the first few microseconds of the return stroke, as well as a detailed look at the cooling period which can last for milliseconds. The spectra are recorded digitally and discretely, hence the data can be summed to to view different exposure times revealing long lasting low emission lines during the cooling period as well. Spectral line identification for the natural and triggered lightning are for a range of wavelengths from soft ultraviolet around 3800A to the near infrared at 9500A. The first few microseconds of the lightning return stroke spectrum consists of hydrogen from disassociated water and singly and doubly ionized lines of atomic atmospheric constituents, i.e. argon, nitrogen, and oxygen. Temperatures calculated during this period have been measured above 40000 K. The peak temperature is measured from the first spectrum of the return stroke. After this the channel continuously cools over the lifetime of the return stroke unless there is an increase in the continuing current. Tens of microseconds after the onset, a cool period in the spectra exists which consists solely of neutral atomic emission lines. The cooling period temperature measurements begin in the low 20000 K range and decrease slowly over the course of milliseconds until strength of the emission lines drop below measurement threshold. Besides the return stroke, other specific lightning processes analyzed include stepped leaders, dart-stepped leaders, and m-components within the continuing current. Stepped and dart-stepped leader spectra consist both of pulsing singly ionized lines and steadily growing neutral lines. Each step within these processes cause increased ionization to occur in the channel upward from the step, demonstrating a pulsing temperature throughout the lifetime of these stepped features. Spectra of the stroke processes, m-components and continuing currents, consist of neutral atmospheric emission lines and copper emission lines which demonstrate the long duration of the channel milliseconds after the initial stages. These spectra indicate long lasting low temperatures which should give insight into temperature profiles where NOx reactions occur. From the spectra, emission identification and lifetime as well as calculations of physical parameters such as temperature, number density, and conductivity about each of these processes give insight into what is physically happening within the channel throughout the lifetime of a stroke.

Exploration of Self-Regulation in the Natural Swimming of the Paramecium’s Cilium

DTIC Science & Technology

2012-02-01

aquatic environments. These animals propel themselves, albeit with limited maneuverability, by the synchronous motion of numerous tiny cilia...microtubule pairs are the source of cilium hardness during the power stroke ; there is a critical phase near the end of the power stroke where one cross...return stroke ; therefore, in each beat cycle, there must be a reattachment process of the cross-bridge links and re-hardening of the cilium during the

Electron Microscopic Recording of the Power and Recovery Strokes of Individual Myosin Heads Coupled with ATP Hydrolysis: Facts and Implications.

PubMed

Sugi, Haruo; Chaen, Shigeru; Akimoto, Tsuyoshi

2018-05-04

The most straightforward way to get information on the performance of individual myosin heads producing muscle contraction may be to record their movement, coupled with ATP hydrolysis, electron-microscopically using the gas environmental chamber (EC). The EC enables us to visualize and record ATP-induced myosin head movement in hydrated skeletal muscle myosin filaments. When actin filaments are absent, myosin heads fluctuate around a definite neutral position, so that their time-averaged mean position remains unchanged. On application of ATP, myosin heads are found to move away from, but not towards, the bare region, indicating that myosin heads perform a recovery stroke (average amplitude, 6 nm). After exhaustion of ATP, myosin heads return to their neutral position. In the actin⁻myosin filament mixture, myosin heads form rigor actin myosin linkages, and on application of ATP, they perform a power stroke by stretching adjacent elastic structures because of a limited amount of applied ATP ≤ 10 µM. The average amplitude of the power stroke is 3.3 nm and 2.5 nm at the distal and the proximal regions of the myosin head catalytic domain (CAD), respectively. The power stroke amplitude increases appreciably at low ionic strength, which is known to enhance Ca 2+ -activated force in muscle. In both the power and recovery strokes, myosin heads return to their neutral position after exhaustion of ATP.

Numerical Calculation of the Spectrum of the Severe (1%) Lighting Current and Its First Derivative

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

Brown, C G; Ong, M M; Perkins, M P

2010-02-12

Recently, the direct-strike lighting environment for the stockpile-to-target sequence was updated [1]. In [1], the severe (1%) lightning current waveforms for first and subsequent return strokes are defined based on Heidler's waveform. This report presents numerical calculations of the spectra of those 1% lightning current waveforms and their first derivatives. First, the 1% lightning current models are repeated here for convenience. Then, the numerical method for calculating the spectra is presented and tested. The test uses a double-exponential waveform and its first derivative, which we fit to the previous 1% direct-strike lighting environment from [2]. Finally, the resulting spectra aremore » given and are compared with those of the double-exponential waveform and its first derivative.« less

[Neuroplasticity as a basis for early rehabilitation of stroke patients].

PubMed

Putilina, M V

2011-01-01

The review is devoted to the current state of the problem of early rehabilitation of stroke patients. The rate of primary disability in patients after stroke is 3.2 per 10000 population but only 20% of previously working patients return to work. Early rehabilitation is treatment actions during a period following stroke. Adequate treatment during this period may decrease the extent of brain damage and improve disease outcome. The complexity of rehabilitation consists in using several complementary pharmacological and non-pharmacological rehabilitation measures. Appearance of new techniques of rehabilitation treatment aimed at neuroplasticity stimulation increases treatment potential of rehabilitative technologies.

Improvements to a High Spectral Resolution, Radiation-Hydrodynamics Model of a Lightning Return Stroke and Comparisons with Measured Spectra and Inferred Plasma Properties

NASA Astrophysics Data System (ADS)

Edwards, J. D.; Dreike, P.; Smith, M. W.; Clemenson, M. D.; Zollweg, J. D.

2015-12-01

We describe developments to a 1-D cylindrical, radiation-hydrodynamics model of a lightning return stroke that simulates lighting spectra with 1 Angstrom resolution in photon wavelength. In previous calculations we assumed standard density air in the return stroke channel and the resulting optical spectrum was that of an optically thick emitter, unlike measured spectra that are optically thin. In this work, we improve our model by initializing our simulation assuming that the leader-heated channel is pre-expanded to a density of 0.01-0.05 ambient and near pressure equilibrium with the surrounding ambient air and by implementing a time-dependent, external heat source to incorporate the effects of continuing current. By doing so, our simulated spectra, illustrated in the attached figure, show strong spectral emission characteristics at wavelengths similar to spectra measured by Orville (1968). In this poster, we describe our model and compare our simulated results with spectra measured by Orville (1968) and Smith (2015). We also use spectroscopic methods to compute physical properties of the plasma channel, e.g. temperature, from Smith's measurements and compare these with our simulated results.

Progression of cognitive impairment in stroke/TIA patients over 3 years.

PubMed

Sachdev, Perminder S; Lipnicki, Darren M; Crawford, John D; Wen, Wei; Brodaty, Henry

2014-12-01

To examine how cognitive deficits progress in the years following a stroke or transient ischaemic attack (TIA). A follow-up study, with neuropsychological and MRI assessments undertaken 3 years after baseline assessments made 3-6 months poststroke in 183 stroke/TIA patients and 97 healthy controls participating in the Sydney Stroke Study. Additional measures included cardiovascular risk factors and apolipoprotein E (APOE) genotype. Stroke/TIA patients had poorer cognitive function and more vascular risk factors than controls at baseline, but did not show greater decline in cognitive function over 3 years except for verbal memory. Patients with a subsequent stroke/TIA showed greater decline in global cognitive function and a number of domains. Rates of incident dementia were 5.9% per year in patients and 0.4% in controls. Both groups showed increased atrophy of the hippocampus, amygdala and whole brain, and an increase in white matter hyperintensities over 3 years; whole brain atrophy was greater in patients. Cognitive decline was greater in women and in those with smaller hippocampi at baseline. For patients without a subsequent stroke/TIA, those with smaller hippocampi or the APOE ε4 allele had greater global cognitive and verbal memory decline. In poststroke patients, cognitive decline was not greater than in comparison subjects, except for verbal memory, unless they had another stroke/TIA. However, dementia incidence was higher in patients, as might be expected from their poorer baseline cognitive functioning. Smaller hippocampi were associated with an increased risk of decline in memory, and APOE ε4 was a risk factor in those without a subsequent stroke/TIA. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Tai Chi-based exercise program provided via telerehabilitation compared to home visits in a post-stroke population who have returned home without intensive rehabilitation: study protocol for a randomized, non-inferiority clinical trial

PubMed Central

2014-01-01

Background The incidence of strokes in industrialized nations is on the rise, particularly in the older population. In Canada, a minority of individuals who have had a stroke actually receive intensive rehabilitation because most stroke patients do not have access to services or because their motor recovery was judged adequate to return home. Thus, there is a considerable need to organize home-based rehabilitation services for everyone who has had a stroke. To meet this demand, telerehabilitation, particularly from a service center to the patient’s home, is a promising alternative approach that can help improve access to rehabilitation services once patients are discharged home. Methods/Design This non-inferiority study will include patients who have returned home post-stroke without requiring intensive rehabilitation. To be included in the study, participants will: 1) not be referred to an Intensive Functional Rehabilitation Unit, 2) have a Rankin score of 2 or 3, and 3) have a balance problem (Berg Balance Scale score between 46 and 54). Participants will be randomly assigned to either the teletreatment group or the home visits group. Except for the delivery mode, the intervention will be the same for both groups, that is, a personalized Tai Chi-based exercise program conducted by a trained physiotherapist (45-minute session twice a week for eight consecutive weeks). The main objective of this research is to test the non-inferiority of a Tai Chi-based exercise program provided via telerehabilitation compared to the same program provided in person at home in terms of effectiveness for retraining balance in individuals who have had a stroke but do not require intensive functional rehabilitation. The main outcome of this study is balance and mobility measured with the Community Balance and Mobility Scale. Secondary outcomes include physical and psychological capacities related to balance and mobility, participants’ quality of life, satisfaction with services received, and cost-effectiveness associated with the provision of both types of services. Study/trial registration ClinicalTrials.gov: NCT01848080 PMID:24479760

Tai Chi-based exercise program provided via telerehabilitation compared to home visits in a post-stroke population who have returned home without intensive rehabilitation: study protocol for a randomized, non-inferiority clinical trial.

PubMed

Tousignant, Michel; Corriveau, Hélène; Kairy, Dahlia; Berg, Katherine; Dubois, Marie-France; Gosselin, Sylvie; Swartz, Richard H; Boulanger, Jean-Martin; Danells, Cynthia

2014-01-30

The incidence of strokes in industrialized nations is on the rise, particularly in the older population. In Canada, a minority of individuals who have had a stroke actually receive intensive rehabilitation because most stroke patients do not have access to services or because their motor recovery was judged adequate to return home. Thus, there is a considerable need to organize home-based rehabilitation services for everyone who has had a stroke. To meet this demand, telerehabilitation, particularly from a service center to the patient's home, is a promising alternative approach that can help improve access to rehabilitation services once patients are discharged home. This non-inferiority study will include patients who have returned home post-stroke without requiring intensive rehabilitation. To be included in the study, participants will: 1) not be referred to an Intensive Functional Rehabilitation Unit, 2) have a Rankin score of 2 or 3, and 3) have a balance problem (Berg Balance Scale score between 46 and 54). Participants will be randomly assigned to either the teletreatment group or the home visits group. Except for the delivery mode, the intervention will be the same for both groups, that is, a personalized Tai Chi-based exercise program conducted by a trained physiotherapist (45-minute session twice a week for eight consecutive weeks). The main objective of this research is to test the non-inferiority of a Tai Chi-based exercise program provided via telerehabilitation compared to the same program provided in person at home in terms of effectiveness for retraining balance in individuals who have had a stroke but do not require intensive functional rehabilitation. The main outcome of this study is balance and mobility measured with the Community Balance and Mobility Scale. Secondary outcomes include physical and psychological capacities related to balance and mobility, participants' quality of life, satisfaction with services received, and cost-effectiveness associated with the provision of both types of services. ClinicalTrials.gov: NCT01848080.

Stroke Risk and Mortality in Patients with Ventricular Assist Devices

PubMed Central

Parikh, Neal S.; Cool, Joséphine; Karas, Maria G.; Boehme, Amelia K.; Kamel, Hooman

2016-01-01

Background and Purpose Ventricular assist devices (VADs) have advanced the management of end-stage heart failure. However, these devices are associated with hemorrhagic and thrombotic complications, including stroke. We assessed the incidence, risk factors, and outcomes of ischemic and hemorrhagic stroke after VAD placement. Methods Using administrative claims data from acute care hospitals in California, Florida, and New York from 2005–2013, we identified patients who underwent VAD placement, defined by International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) code 37.66. Ischemic and hemorrhagic strokes were identified by previously validated coding algorithms. We used survival statistics to determine incidence rates and Cox proportional hazard analyses to examine associations. Results Among 1,813 patients, we identified 201 ischemic strokes and 116 hemorrhagic strokes during 3.4 (±2.0) years of follow-up after implantation of a VAD. The incidence of stroke was 8.7% per year (95% confidence interval [CI], 7.7–9.7%). The annual incidence of ischemic stroke (5.5%; 95% CI, 4.8–6.4%) was nearly double that of hemorrhagic stroke (3.1%; 95% CI, 2.6–3.8%). Women faced a higher hazard of stroke than men (hazard ratio [HR], 1.6; 95% CI, 1.2–2.1), particularly hemorrhagic stroke (HR, 2.2; 95% CI, 1.4–3.4). Stroke was strongly associated with subsequent in-hospital mortality (HR, 6.1; 95% CI, 4.6–7.9). Conclusions The incidence of stroke after VAD implantation was 8.7% per year, and incident stroke was strongly associated with subsequent in-hospital mortality. Notably, ischemic stroke occurred at nearly twice the rate of hemorrhagic stroke. Women appeared to face a higher risk for hemorrhagic stroke than men. PMID:27650070

Stroke Risk and Mortality in Patients With Ventricular Assist Devices.

PubMed

Parikh, Neal S; Cool, Joséphine; Karas, Maria G; Boehme, Amelia K; Kamel, Hooman

2016-11-01

Ventricular assist devices (VADs) have advanced the management of end-stage heart failure. However, these devices are associated with hemorrhagic and thrombotic complications, including stroke. We assessed the incidence, risk factors, and outcomes of ischemic and hemorrhagic stroke after VAD placement. Using administrative claims data from acute care hospitals in California, Florida, and New York from 2005 to 2013, we identified patients who underwent VAD placement, defined by the International Classification of Diseases, Ninth Revision, Clinical Modification code 37.66. Ischemic and hemorrhagic strokes were identified by previously validated coding algorithms. We used survival statistics to determine the incidence rates and Cox proportional hazard analyses to examine the associations. Among 1813 patients, we identified 201 ischemic strokes and 116 hemorrhagic strokes during 3.4 (±2.0) years of follow-up after implantation of a VAD. The incidence of stroke was 8.7% per year (95% confidence interval [CI], 7.7-9.7). The annual incidence of ischemic stroke (5.5%; 95% CI, 4.8-6.4) was nearly double that of hemorrhagic stroke (3.1%; 95% CI, 2.6-3.8). Women faced a higher hazard of stroke than men (hazard ratio, 1.6; 95% CI, 1.2-2.1), particularly hemorrhagic stroke (hazard ratio, 2.2; 95% CI, 1.4-3.4). Stroke was strongly associated with subsequent in-hospital mortality (hazard ratio, 6.1; 95% CI, 4.6-7.9). The incidence of stroke after VAD implantation was 8.7% per year, and incident stroke was strongly associated with subsequent in-hospital mortality. Notably, ischemic stroke occurred at nearly twice the rate of hemorrhagic stroke. Women seemed to face a higher risk for hemorrhagic stroke than men. © 2016 American Heart Association, Inc.

Socioeconomic factors' effect on return to work after first stroke.

PubMed

Glader, E-L; Jonsson, B; Norrving, B; Eriksson, M

2017-06-01

The objective of this nationwide study was to analyze how functional status and socioeconomic status affect return to work (RTW) among younger patients with first-time stroke in a Sweden. This register-based cohort study included employed patients aged 25-55 with first-time stroke between 2008 and 2011 and primary outcome was RTW within 1 year after stroke. Data regarding functional status and employment status were retrieved from the Swedish Stroke Register, Riksstroke, and socioeconomic data (income, education, and country of birth) from Statistics Sweden. We included 2539 patients who had answered the question on RTW, and 1880 (74.0%) had RTW within 12 months. Patients with low income (69.9% in lowest income group vs 79.9% in highest group, P<.001), patients born in countries outside the Nordic countries (Sweden 75.5%, Nordic countries 74.3%, European countries 61.7%, other countries 57.3%, P<.001), and the youngest patients (25-34, 63.1%; 35-44, 75.9%; 45-55, 74.3%; P=.008) were less likely to RTW. Pain, low mood, and answering the questionnaire with help were more common in low socioeconomic groups, and when adjusting for these variables, together with age and sex, income and country of birth were no longer independent predictors for RTW. Patients with low socioeconomic status less often RTW 1 year after stroke.Impaired functional status after stroke is more common in patients with lower socioeconomic status and mediates socioeconomic differences in RTW. Improvement of functional status should be targeted to facilitate RTW among stroke patients with low socioeconomic status. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Aphasia and Auditory Processing after Stroke through an International Classification of Functioning, Disability and Health Lens

PubMed Central

Purdy, Suzanne C.; Wanigasekara, Iruni; Cañete, Oscar M.; Moore, Celia; McCann, Clare M.

2016-01-01

Aphasia is an acquired language impairment affecting speaking, listening, reading, and writing. Aphasia occurs in about a third of patients who have ischemic stroke and significantly affects functional recovery and return to work. Stroke is more common in older individuals but also occurs in young adults and children. Because people experiencing a stroke are typically aged between 65 and 84 years, hearing loss is common and can potentially interfere with rehabilitation. There is some evidence for increased risk and greater severity of sensorineural hearing loss in the stroke population and hence it has been recommended that all people surviving a stroke should have a hearing test. Auditory processing difficulties have also been reported poststroke. The International Classification of Functioning, Disability and Health (ICF) can be used as a basis for describing the effect of aphasia, hearing loss, and auditory processing difficulties on activities and participation. Effects include reduced participation in activities outside the home such as work and recreation and difficulty engaging in social interaction and communicating needs. A case example of a young man (M) in his 30s who experienced a left-hemisphere ischemic stroke is presented. M has normal hearing sensitivity but has aphasia and auditory processing difficulties based on behavioral and cortical evoked potential measures. His principal goal is to return to work. Although auditory processing difficulties (and hearing loss) are acknowledged in the literature, clinical protocols typically do not specify routine assessment. The literature and the case example presented here suggest a need for further research in this area and a possible change in practice toward more routine assessment of auditory function post-stroke. PMID:27489401

Multifactorial analysis of factors affecting recurrence of stroke in Japan.

PubMed

Omori, Toyonori; Kawagoe, Masahiro; Moriyama, Michiko; Yasuda, Takeshi; Ito, Yasuhiro; Hyakuta, Takeshi; Nagatsuka, Kazuyuki; Matsumoto, Masayasu

2015-03-01

Data on factors affecting stroke recurrence are relatively limited. The authors examined potential factors affecting stroke recurrence, retrospectively. The study participants were 1087 patients who were admitted to stroke centers suffering from first-ever ischemic stroke and returned questionnaires with usable information after discharge. The authors analyzed the association between clinical parameters of the patients and their prognosis. Recurrence rate of during an average of 2 years after discharge was 21.3%, and there were differences among stroke subtypes. It was found that the disability level of the patients after discharge correlated well with the level at discharge (r s = 0.66). Multivariate logistic regression analysis of the data shows that modified Rankin Scale score, National Institute of Health Stroke Scale score, gender, age, and family history had statistically significant impacts on stroke recurrence, and the impact was different depending on subtypes. These findings suggest that aggressive and persistent health education for poststroke patients and management of risk factors are essential to reduce stroke recurrence. © 2012 APJPH.

Association of Vagotomy and Decreased Risk of Subsequent Ischemic Stroke in Complicated Peptic Ulcer Patients: an Asian Population Study.

PubMed

Fang, Chu-Wen; Tseng, Chun-Hung; Wu, Shih-Chi; Chen, William Tzu-Liang; Muo, Chih-Hsin

2017-12-01

The primary management of peptic ulcers is medical treatment. Persistent exacerbation of a peptic ulcer may lead to complications (perforation and/or bleeding). There has been a trend toward the use of a less invasive surgical simple suture, simple local suture or non-operative (endoscopic/angiography) hemostasis rather than acid-reducing vagotomy (i.e., vagus nerve severance) for treating complicated peptic ulcers. Other studies have shown the relationship between high vagus nerve activity and survival in cancer patients via reduced levels of inflammation, indicating the essential role of the vagus nerve. We were interested in the role of the vagus nerve and attempted to assess the long-term systemic effects after vagus nerve severance. Complicated peptic ulcer patients who underwent truncal vagotomy may represent an appropriate study population for investigating the association between vagus nerve severance and long-term effects. Therefore, we assessed the risks of subsequent ischemic stroke using different treatment methods in complicated peptic ulcer patients who underwent simple suture/hemostasis or truncal vagotomy/pyloroplasty. We selected 299,742 peptic ulcer patients without a history of stroke and Helicobacter pylori infection and an additional 299,742 matched controls without ulcer, stroke, and Helicobacter pylori infection from the National Health Insurance database. The controls were frequency matched for age, gender, Charlson comorbidity index (CCI) score, hypertension, hyperlipidemia history, and index year. Then, we measured the incidence of overall ischemic stroke in the two cohorts. The hazard ratio (HR) and the 95% confidence intervals (CIs) were estimated by Cox proportional hazard regression. Compared to the controls, peptic ulcer patients had a 1.86-fold higher risk of ischemic stroke. There were similar results in gender, age, CCI, hypertension, and hyperlipidemia stratified analyses. In complicated peptic ulcer patients, those who received truncal vagotomy and pyloroplasty had a lower risk of ischemic stroke than patients who received simple suture/hemostasis (HR = 0.70, 95% CI = 0.60-0.81). Our findings suggest that patients with peptic ulcers have an elevated risk of subsequent ischemic stroke. Moreover, there were associations between vagotomy and a decreased risk of subsequent ischemic stroke in complicated peptic ulcer patients.

Changes in Depressive Symptoms and Subsequent Risk of Stroke in the Cardiovascular Health Study

PubMed Central

Gilsanz, Paola; Kubzansky, Laura D.; Tchetgen Tchetgen, Eric J.; Wang, Qianyi; Kawachi, Ichiro; Patton, Kristen K.; Fitzpatrick, Annette L.; Kop, Willem J.; Longstreth, W.T.; Glymour, M. Maria

2016-01-01

Background and Purpose Depression is associated with stroke, but the effects of changes in depressive symptoms on stroke risk are not well understood. This study examined whether depressive symptom changes across two successive annual assessments were associated with incident stroke the following year. Methods We used visit data from 4,319 participants of the Cardiovascular Health Study who were stroke-free at baseline to examine whether changes in depressive symptoms classified across two consecutive annual assessments predicted incident first stroke during the subsequent year. Depressive symptoms were assessed using the 10-item Center for Epidemiologic Studies Depression scale (CES-D; high vs. low at ≥10). Survival models were inverse probability weighted to adjust for demographics, health behaviors, medical conditions, past depressive symptoms, censoring, and survival. Results During follow-up, 334 strokes occurred. Relative to stable low scores of depressive symptoms, improved depression symptoms were associated with almost no excess risk of stroke (aHR=1.02; 95% CI: 0.66–1.58). New-onset symptoms were non-significantly associated with elevated stroke risk (aHR=1.44; 95% CI: 0.97–2.14) while persistently high depressive symptoms were associated with elevated adjusted hazard of all-cause stroke (aHR=1.65; 95% CI: 1.06–2.56). No evidence for effect modification by race, age, or sex was found. Conclusions Persistently high symptoms of depression predicted elevated hazard of stroke. Participants with improved depressive symptoms had no elevation in stroke risk. Such findings suggest that strategies to reduce depressive symptoms may ameliorate stroke risk. PMID:27924053

Detection and analysis of radio frequency lightning emissions

NASA Technical Reports Server (NTRS)

Jalali, F.

1982-01-01

The feasibility study of detection of lightning discharges from a geosynchronous satellite requires adequate ground-based information regarding emission characteristics. In this investigation, a measurement system for collection of S-band emission data is set up and calibrated, and the operations procedures for rapid data collection during a storm activity developed. The system collects emission data in two modes; a digitized, high-resolution, short duration record stored in solid-state memory, and a continuous long-duration record on magnetic tape. Representative lightning flash data are shown. Preliminary results indicate appreciable RF emissions at 2 gHz from both the leader and return strokes portions of the cloud-to-ground discharge with strong peaks associated with the return strokes.

Mechanical energy absorber

NASA Technical Reports Server (NTRS)

Wesselski, Clarence J. (Inventor)

1993-01-01

An energy absorbing system for controlling the force where a moving object engages a stationary stop and where the system utilized telescopic tubular members, energy absorbing diaphragm elements, force regulating disc springs, and a return spring to return the telescoping member to its start position after stroking is presented. The energy absorbing system has frusto-conical diaphragm elements frictionally engaging the shaft and are opposed by a force regulating set of disc springs. In principle, this force feedback mechanism serves to keep the stroking load at a reasonable level even if the friction coefficient increases greatly. This force feedback device also serves to desensitize the singular and combined effects of manufacturing tolerances, sliding surface wear, temperature changes, dynamic effects, and lubricity.

The start of lightning: Evidence of bidirectional lightning initiation.

PubMed

Montanyà, Joan; van der Velde, Oscar; Williams, Earle R

2015-10-16

Lightning flashes are known to initiate in regions of strong electric fields inside thunderstorms, between layers of positively and negatively charged precipitation particles. For that reason, lightning inception is typically hidden from sight of camera systems used in research. Other technology such as lightning mapping systems based on radio waves can typically detect only some aspects of the lightning initiation process and subsequent development of positive and negative leaders. We report here a serendipitous recording of bidirectional lightning initiation in virgin air under the cloud base at ~11,000 images per second, and the differences in characteristics of opposite polarity leader sections during the earliest stages of the discharge. This case reveals natural lightning initiation, propagation and a return stroke as in negative cloud-to-ground flashes, upon connection to another lightning channel - without any masking by cloud.

Changing Face of Stroke: Implications for Occupational Therapy Practice

PubMed Central

Wolf, Timothy J.; Baum, Carolyn; Connor, Lisa Tabor

2010-01-01

Stroke is one of the most life-altering syndromes affecting the world population. Rehabilitation for people experiencing stroke is focused almost exclusively on self-care activities and being able to return home and has little to no focus on work rehabilitation or community reintegration. The Cognitive Rehabilitation Research Group (CRRG) at the Washington University School of Medicine in St. Louis was formed with the vision of improving everyday life for people after stroke by translating knowledge from neuroscience into treatment programs for productive living. Descriptive analysis of the intake assessment from the CRRG Clinical Core (N = 7,740) revealed three important findings: The age at stroke is decreasing, most strokes are neurologically mild to moderate in nature, and discharge placement decisions are being made largely on the basis of measures of impairment. The changes in the stroke population require occupational therapy to expand rehabilitation beyond the acute management of stroke to address full participation in work, family, and community life. PMID:19785261

A population-based study of hospital care costs during five years after TIA and stroke

PubMed Central

Luengo-Fernandez, Ramon; Gray, Alastair M.; Rothwell, Peter M.

2016-01-01

Background and Purpose Few studies have evaluated long-term costs after stroke onset, with almost no cost data for TIA. We studied hospital costs during the 5 years after TIA or stroke in a population-based study. Methods Patients from a UK population-based cohort study (Oxford Vascular Study) were recruited from 2002 to 2007. Analysis was based on follow-up until 2010. Hospital resource usage was obtained from patients’ hospital records and valued using 2008/09 unit costs. As not all patients had full 5-year follow-up, we used non-parametric censoring techniques. Results Among 485 TIA and 729 stroke patients ascertained and included, mean censor-adjusted 5-year hospital costs after index stroke were $25,741 (95% CI: 23,659-27,914), with costs varying considerably by severity: $21,134 after minor stroke, $33,119 after moderate stroke, and $28,552 after severe stroke. For the 239 surviving stroke patients who had reached final follow-up, mean costs were $24,383 (20,156-28,595), with over half of costs ($12,972) being incurred in the first year after the event. After index TIA, the mean censor-adjusted 5-year costs were $18,091 (15,947-20,258). A multivariate analysis showed that event severity, recurrent stroke and coronary events after the index event were independent predictors of 5-year costs. Differences by stroke subtype were mostly explained by stroke severity and subsequent events. Conclusions Long-term hospital costs after TIA and stroke are considerable, but are mainly incurred over the first year after the index event. Event severity and suffering subsequent stroke and coronary events after the index event accounted for much of the increase in costs. PMID:23160884

Short-Term Exposure to Fine Particulate Matter and Risk of Ischemic Stroke.

PubMed

Matsuo, Ryu; Michikawa, Takehiro; Ueda, Kayo; Ago, Tetsuro; Nitta, Hiroshi; Kitazono, Takanari; Kamouchi, Masahiro

2016-12-01

There is a strong association between ambient concentrations of particulate matter (PM) and cardiovascular disease. However, it remains unclear whether acute exposure to fine PM (PM 2.5 ) triggers ischemic stroke events and whether the timing of exposure is associated with stroke risk. We, therefore, examined the association between ambient PM 2.5 and occurrence of ischemic stroke. We analyzed data for 6885 ischemic stroke patients from a multicenter hospital-based stroke registry in Japan who were previously independent and hospitalized within 24 hours of stroke onset. Time of symptom onset was confirmed, and the association between PM (suspended PM and PM 2.5 ) and occurrence of ischemic stroke was analyzed by time-stratified case-crossover analysis. Ambient PM 2.5 and suspended PM at lag days 0 to 1 were associated with subsequent occurrence of ischemic stroke (ambient temperature-adjusted odds ratio [95% confidence interval] per 10 μg/m 3 : suspended PM, 1.02 [1.00-1.05]; PM 2.5 , 1.03 [1.00-1.06]). In contrast, ambient suspended PM and PM 2.5 at lag days 2 to 3 or 4 to 6 showed no significant association with stroke occurrence. The association between PM 2.5 at lag days 0 to 1 and ischemic stroke was maintained after adjusting for other air pollutants (nitrogen dioxide, photochemical oxidants, or sulfur dioxide) or influenza epidemics and was evident in the cold season. These findings suggest that short-term exposure to PM 2.5 within 1 day before onset is associated with the subsequent occurrence of ischemic stroke. © 2016 American Heart Association, Inc.

Can overestimation of walking ability increase the risk of falls in people in the subacute stage after stroke on their return home?

PubMed

Morone, G; Iosa, M; Pratesi, L; Paolucci, S

2014-03-01

Falls are common in patients who have had a stroke who return home after neurorehabilitation. Some studies have found that walking speed inversely correlates with the risk of falls. This study examined whether comparison between comfortable self-selected walking speed and maximum maintainable speed is informative with regard to the risk of falls in patients with stroke. A prospective cohort study was performed with 75 ambulant stroke patients. At discharge, the Barthel Index score and performance at the 10-m and 6-min walking tests were assessed. Number of falls was recorded by telephone interview every two months for one year. Regression analysis was performed to identify factors that were related to the risk of falls. Using forward multiple linear regression, only the ratio between walking speeds on the 6-min and 10-m tests was linked to the number of falls in the year after discharge (R=-0.451, p<0.001, OR=0.046). Patients who chose a walking speed for short distances that was not maintainable long term fell more frequently. A discrepancy between short and long-term walking speed can help in identifying subjects in the subacute stage after stroke with an increased risk of suffering a fall. Copyright © 2014 Elsevier B.V. All rights reserved.

Cardiorespiratory responses to orthostasis and the effects of propranolol

NASA Technical Reports Server (NTRS)

Loeppky, J. A.

1975-01-01

Cardiac output and gas exchange were determined serially using the single-breath method of Kim et al. before, during, and after orthostasis on six subjects after beta-adrenergic blockage and in duplicate controls. In the latter, heart rate increased and pulse pressure dropped immediately on tilting to 60 deg and remained stable while cardiac output and stroke volume declined gradually over 21 min upright. On propranolol, heart rate was 10 bpm lower supine and 20 bpm less at 60 deg but cardiac output was only slightly lower before and following tilt-up. However, after 15 min upright, stroke volume and cardiac output recovered on propranolol exceeding the controls after 21 min without change in heart rate. Returning to supine, heart rate dropped in all tests with a transitory increase in stroke volume, cardiac output and arteriovenous O2 difference. At the same time, apparent O2 uptake increased temporarily, reflecting the return of pooled venous blood to the lungs. Orthostatic tolerance did not appear to be affected by beta-adrenergic blockade.

The channel radius and energy of cloud-to-ground lightning discharge plasma with multiple return strokes

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

Wang, Xuejuan; Yuan, Ping; Cen, Jianyong

2014-03-15

Using the spectra of a cloud-to-ground (CG) lightning flash with multiple return strokes and combining with the synchronous radiated electrical field information, the linear charge density, the channel radius, the energy per unit length, the thermal energy, and the energy of dissociation and ionization in discharge channel are calculated with the aid of an electrodynamic model of lightning. The conclusion that the initial radius of discharge channel is determined by the duration of the discharge current is confirmed. Moreover, the correlativity of several parameters has been analyzed first. The results indicate that the total intensity of spectra is positive correlatedmore » to the channel initial radius. The ionization and thermal energies have a linear relationship, and the dissociation energy is correlated positively to the ionization and thermal energies, the energy per unit length is in direct proportion to the square of initial radius in different strokes of one CG lightning.« less

Hospitalization resource use and costs before and after TIA and stroke: results from a population-based cohort study (OXVASC).

PubMed

Luengo-Fernandez, Ramon; Silver, Louise E; Gutnikov, Sergei A; Gray, Alastair M; Rothwell, Peter M

2013-01-01

High hospitalization rates, prolonged length of stay, and increased risks of subsequent events mean a steep increase in health care usage after stroke. No study, however, has examined to what extent increased costs after transient ischemic attack (TIA) or stroke are due to hospitalizations for the initial event, recurrent events, and/or nonvascular hospitalizations, and how costs compare with the year prior to the event. We studied patients in a population-based cohort study (Oxford Vascular Study) in the United Kingdom from 2003 to 2007. Hospitalization and cost details were obtained from patients' individualized Hospital Episode Statistics records. A total of 295 incident TIA and 439 incident stroke patients were included. For patients with stroke, average costs increased from £1437 in the year pre-event to £6629 in the year post-event (P<0.0001). Sixty-four percent (£4224) of poststroke costs were due to hospitalizations linked to the index stroke, more than 30% of which were given nonvascular primary diagnoses on Hospital Episode Statistics, and £653 (10%) were due to hospitalizations linked to subsequent vascular events. For patients with TIA, costs increased from £876 1 year before the event to £2410 in the year post-event (P<0.0001). Patients with TIA incurred nonsignificantly higher costs due to hospitalizations linked to subsequent vascular events (£774) than for hospitalizations linked to the index TIA (£720). Hospital costs increased after TIA or stroke, primarily because of increased initial cerebrovascular hospitalizations. The finding that costs due to nonvascular diagnoses also increased after TIA or stroke appears, in part, to be explained by the miscoding of TIA/stroke-related hospitalizations in electronic information systems. Copyright © 2013 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Service provision for stroke: The Greek paradox.

PubMed

Fountouki, Antigoni; Theofanidis, Dimitrios

2017-09-01

Stroke remains a leading cause of mortality, as well as of subsequent serious long-term physical and mental morbidity. This places special demands for updated clinical excellence and optimum organization of stroke care services. Stroke units have been shown to improve patient outcomes. Thus, many western countries have developed and implemented sophisticated stroke facilities and corresponding public awareness strategies. These cannot be easily "translated" in Greece due to special features on the hospital administration system such as a unique rotation system for acute admissions and long-standing austerity. Yet, despite adverse conditions, clinicians within the Greek health care system have been exceeding themselves in their attempt to provide optimum care outcomes. An example of such efforts is the improvisation of stroke bays (SBs) as part of a medical or neurology ward, providing sophisticated treatments. New centralized policy decisions are now needed in order to improve stroke services nationwide. These should be tailored to the country's geography and health care mapping especially as there is already considerable technical knowhow and local efforts in place. A pragmatic solution would be to create a "grid" of services for stroke, by providing a comprehensive stroke centers in each of the two major cities and SBs at a prefectural level. Once these are established, more efforts should be taken to educate the public on stroke recognition and subsequently on facilities available. Copyright © 2017 Society for Vascular Nursing, Inc. Published by Elsevier Inc. All rights reserved.

Anomalous light output from lightning dart leaders

NASA Technical Reports Server (NTRS)

Guo, C.; Krider, E. P.

1985-01-01

About 5 percent of the multiple-stroke cloud-to-ground lightning discharges recorded at the NASA Kennedy Space Center during the summer of 1981 contained dart leaders that produced an unusually large light output. An analysis of these cases indicates that the average peak light output per unit length in the leader may be comparable to or even exceed that of the return stroke that follows.

The dE/dt and E Waveforms Radiated by Leader Steps Just Before the First Return Stroke in Cloud-to-Ocean Lightning

NASA Astrophysics Data System (ADS)

Krider, E. P.; Baffou, G.; Murray, N. D.; Willett, J. C.

2004-12-01

We have analyzed the shapes and other characteristics of the electric field, E, and dE/dt waveforms that were radiated by leader steps just before the first return stroke in cloud-to-ocean lightning. dE/dt waveforms were recorded using an 8-bit digitizer sampling at 100 MHz, and an integrated waveform, Eint, was computed by numerically integrating dE/dt and comparing the result with an analog E waveform digitized at 10 MHz. All signals were recorded under conditions where the lightning locations were known and there was minimal distortion in the fields due to the effects of ground-wave propagation. The dE/dt waveforms radiated by leader steps tend to fall into three categories: (1) "simple" - an isolated negative peak that is immediately followed by a positive overshoot (where negative polarity follows the normal physics convention), (2) "double" - two simple waveforms that occur at almost the same time, and (3) "burst" - a complex cluster of pulses with a total duration of about one microsecond. In this paper, we will give examples of each of these waveform types, and we will summarize their characteristics on a submicrosecond time-scale. For example, in an interval starting 9 μ s before to 4 μ s before the largest, negative (dominant) peak in dE/dt peak in the return stroke, 131 first strokes produced a total of 296 impulses with a peak amplitude greater than 10% of the dominant peak, and the average amplitude of these pulses was 0.21 of the dominant peak. The last leader step in a 12 μ s interval before the dominant peak was a simple waveform in 51 first strokes, and in these cases, the average time-interval between the peak dE/dt of the step and the dominant peak of the stroke was 5.8 ± 1.7 μ s, a value that is in good agreement with prior measurements. The median full-width-at-half-maximum (FWHM) of 274 simple Eint signatures was 141 ns, and the associated mean and standard deviation were 187 ± 131 ns.

Acute Predictors of Social Integration Following Mild Stroke.

PubMed

Wise, Frances M; Harris, Darren W; Olver, John H; Davis, Stephen M; Disler, Peter B

2018-04-01

Despite an acknowledged need to accurately predict stroke outcome, there is little empirical evidence regarding acute predictors of participation restriction post stroke. The current study examines prediction of social integration following mild stroke, using combinations of acute poststroke factors. In a prospective, longitudinal study, a cohort of 60 stroke survivors was followed up at 6 months post stroke. Hierarchical multiple regression analyses were employed to evaluate the value of acute poststroke variables in predicting social integration at 6 months post stroke. A combination of age, number of comorbidities, stroke severity, social support factors, and general self-efficacy in the acute poststroke period accounted for 42% of the variance in 6-month social integration. The largest amount of variance (20%) was explained by inclusion of social support factors, including number and types of support. Post hoc analysis was conducted to establish whether marital status was the mediating variable through which early poststroke social support factors exerted influence upon subsequent social integration. The new combination of acute variables accounted for 48% of the variance in 6-month social integration. Results suggested that subjects with partners perceived higher levels of functional social support and lower levels of participation restriction. Stroke survivors with partners may receive greater amounts of companionship and encouragement from their partners, which enhances self-esteem and confidence. Such individuals are possibly more able to participate in and maintain relationships, thus improving social integration. Social support factors, mediated via marital status, are the strongest predictors of subsequent social integration following mild stroke. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

One-Year Outcomes After Minor Stroke or High-Risk Transient Ischemic Attack: Korean Multicenter Stroke Registry Analysis.

PubMed

Park, Hong-Kyun; Kim, Beom Joon; Han, Moon-Ku; Park, Jong-Moo; Kang, Kyusik; Lee, Soo Joo; Kim, Jae Guk; Cha, Jae-Kwan; Kim, Dae-Hyun; Nah, Hyun-Wook; Park, Tai Hwan; Park, Sang-Soon; Lee, Kyung Bok; Lee, Jun; Hong, Keun-Sik; Cho, Yong-Jin; Lee, Byung-Chul; Yu, Kyung-Ho; Oh, Mi-Sun; Kim, Joon-Tae; Choi, Kang-Ho; Kim, Dong-Eog; Ryu, Wi-Sun; Choi, Jay Chol; Johansson, Saga; Lee, Su Jin; Lee, Won Hee; Lee, Ji Sung; Lee, Juneyoung; Bae, Hee-Joon

2017-11-01

Patients with minor ischemic stroke or transient ischemic attack are at high risk of recurrent stroke and vascular events, which are potentially disabling or fatal. This study aimed to evaluate contemporary subsequent vascular event risk after minor ischemic stroke or transient ischemic attack in Korea. Patients with minor ischemic stroke or high-risk transient ischemic attack admitted within 7 days of symptom onset were identified from a Korean multicenter stroke registry database. We estimated 3-month and 1-year event rates of the primary outcome (composite of stroke recurrence, myocardial infarction, or all-cause death), stroke recurrence, a major vascular event (composite of stroke recurrence, myocardial infarction, or vascular death), and all-cause death and explored differences in clinical characteristics and event rates according to antithrombotic strategies at discharge. Of 9506 patients enrolled in this study, 93.8% underwent angiographic assessment and 72.7% underwent cardiac evaluations; 25.1% had symptomatic stenosis or occlusion of intracranial arteries. At discharge, 95.2% of patients received antithrombotics (antiplatelet polytherapy, 37.1%; anticoagulation, 15.3%) and 86.2% received statins. The 3-month cumulative event rate was 5.9% for the primary outcome, 4.3% for stroke recurrence, 4.6% for a major vascular event, and 2.0% for all-cause death. Corresponding values at 1 year were 9.3%, 6.1%, 6.7%, and 4.1%, respectively. Patients receiving nonaspirin antithrombotic strategies or no antithrombotic agent had higher baseline risk profiles and at least 1.5× higher event rates for clinical event outcomes than those with aspirin monotherapy. Contemporary secondary stroke prevention strategies based on thorough diagnostic evaluation may contribute to the low subsequent vascular event rates observed in real-world clinical practice in Korea. © 2017 American Heart Association, Inc.

A Delphi study and ranking exercise to support commissioning services: future delivery of Thrombectomy services in England.

PubMed

Halvorsrud, Kristoffer; Flynn, Darren; Ford, Gary A; McMeekin, Peter; Bhalla, Ajay; Balami, Joyce; Craig, Dawn; White, Phil

2018-02-22

Intra-arterial thrombectomy is the gold standard treatment for large artery occlusive stroke. However, the evidence of its benefits is almost entirely based on trials delivered by experienced neurointerventionists working in established teams in neuroscience centres. Those responsible for the design and prospective reconfiguration of services need access to a comprehensive and complementary array of information on which to base their decisions. This will help to ensure the demonstrated effects from trials may be realised in practice and account for regional/local variations in resources and skill-sets. One approach to elucidate the implementation preferences and considerations of key experts is a Delphi survey. In order to support commissioning decisions, we aimed using an electronic Delphi survey to establish consensus on the options for future organisation of thrombectomy services among physicians with clinical experience in managing large artery occlusive stroke. A Delphi survey was developed with 12 options for future organisation of thrombectomy services in England. A purposive sampling strategy established an expert panel of stroke physicians from the British Association of Stroke Physicians (BASP) Clinical Standards and/or Executive Membership that deliver 24/7 intravenous thrombolysis. Options with aggregate scores falling within the lowest quartile were removed from the subsequent Delphi round. Options reaching consensus following the two Delphi rounds were then ranked in a final exercise by both the wider BASP membership and the British Society of Neuroradiologists (BSNR). Eleven stroke physicians from BASP completed the initial two Delphi rounds. Three options achieved consensus, with subsequently wider BASP (97%, n = 43) and BSNR members (86%, n = 21) assigning the highest approval rankings in the final exercise for transferring large artery occlusive stroke patients to nearest neuroscience centre for thrombectomy based on local CT/CT Angiography. The initial Delphi rounds ensured optimal reduction of options by an expert panel of stroke physicians, while subsequent ranking exercises allowed remaining options to be ranked by a wider group of experts within stroke to reach consensus. The preferred implementation option for thrombectomy is investigating suspected acute stroke patients by CT/CT Angiography and secondary transfer of large artery occlusive stroke patients to the nearest neuroscience (thrombectomy) centre.

Lightning data study in conjunction with geostationary satellite data

NASA Technical Reports Server (NTRS)

Auvine, Brian; Martin, David W.

1987-01-01

During the summer of 1985, cloud-to-ground stroke lightning were collected. Thirty minute samples of lightning were compared with GOES IR fractional cold cloud coverage computed for three temperature thresholds (213, 243, and 273 K) twice daily (morning and evening). It was found that satellite measurements of cold cloud have a relationship to the flashrate and, in a more limited way, to the polarity and numbers of return strokes. Results varied little by location. Lightning, especially positive strokes, was found to be correlated with fractional cloud coverage, especially for clouds at or below 213 K. Other data and correlations are discussed.

Radio frequency observations of lightning discharges by the forte satellite.

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

Shao, X.; Jacobson, A. R.; Light, T.

2002-01-01

FORTE-observed VHF signatures for different lightning discharges are presented. For in-cloud discharges, a pulse pair is typically recorded and is named a 'transionospheric pulse pair' (TIPP). Many intense TIPPs are coherent and polarized, whereas initial and dart leaders do not show a recognizable degree of polarization. TIPPs are optically weaker than cloud-to-ground (CG) strokes, and stronger VHF TIPPs are optically darker. About 10% of CG strokes, mostly over seawater, produce extremely narrow, powerful VHF pulses at the very beginning of the return strokes. These narrow pulses are found to form an upward beam pattern.

Lost Productivity in Stroke Survivors: An Econometrics Analysis.

PubMed

Vyas, Manav V; Hackam, Daniel G; Silver, Frank L; Laporte, Audrey; Kapral, Moira K

2016-01-01

Stroke leads to a substantial societal economic burden. Loss of productivity among stroke survivors is a significant contributor to the indirect costs associated with stroke. We aimed to characterize productivity and factors associated with employability in stroke survivors. We used the Canadian Community Health Survey 2011-2012 to identify stroke survivors and employment status. We used multivariable logistic models to determine the impact of stroke on employment and on factors associated with employability, and used Heckman models to estimate the effect of stroke on productivity (number of hours worked/week and hourly wages). We included data from 91,633 respondents between 18 and 70 years and identified 923 (1%) stroke survivors. Stroke survivors were less likely to be employed (adjusted OR 0.39, 95% CI 0.33-0.46) and had hourly wages 17.5% (95% CI 7.7-23.7) lower compared to the general population, although there was no association between work hours and being a stroke survivor. We found that factors like older age, not being married, and having medical comorbidities were associated with lower odds of employment in stroke survivors in our sample. Stroke survivors are less likely to be employed and they earn a lower hourly wage than the general population. Interventions such as dedicated vocational rehabilitation and policies targeting return to work could be considered to address this lost productivity among stroke survivors. © 2016 S. Karger AG, Basel.

Stroke survivors over-estimate their medication self-administration (MSA) ability, predicting memory loss.

PubMed

Barrett, A M; Galletta, Elizabeth E; Zhang, Jun; Masmela, Jenny R; Adler, Uri S

2014-01-01

Medication self-administration (MSA) may be cognitively challenging after stroke, but guidelines are currently lacking for identifying high-functioning stroke survivors who may have difficulty with this task. Complicating this matter, stroke survivors may not be aware of their cognitive problems (cognitive anosognosia) and may over-estimate their MSA competence. The authors wished to evaluate medication self-administration and MSA self-awareness in 24 consecutive acute stroke survivors undergoing inpatient rehabilitation, to determine if they would over-estimate their medication self-administration and if this predicted memory disorder. Stroke survivors were tested on the Hopkins Medication Schedule and also their memory, naming mood and dexterity were evaluated, comparing their performance to 17 matched controls. The anosognosia ratio indicated MSA over-estimation in stroke survivors compared with controls--no other over-estimation errors were noted relative to controls. A strong correlation was observed between over-estimation of MSA ability and verbal memory deficit, suggesting that formally assessing MSA and MSA self-awareness may help detect cognitive deficits. Assessing medication self-administration and MSA self-awareness may be useful in rehabilitation and successful community-return after stroke.

The Role of Citicoline in Neuroprotection and Neurorepair in Ischemic Stroke

PubMed Central

Álvarez-Sabín, José; Román, Gustavo C.

2013-01-01

Advances in acute stroke therapy resulting from thrombolytic treatment, endovascular procedures, and stroke units have improved significantly stroke survival and prognosis; however, for the large majority of patients lacking access to advanced therapies stroke mortality and residual morbidity remain high and many patients become incapacitated by motor and cognitive deficits, with loss of independence in activities of daily living. Therefore, over the past several years, research has been directed to limit the brain lesions produced by acute ischemia (neuroprotection) and to increase the recovery, plasticity and neuroregenerative processes that complement rehabilitation and enhance the possibility of recovery and return to normal functions (neurorepair). Citicoline has therapeutic effects at several stages of the ischemic cascade in acute ischemic stroke and has demonstrated efficiency in a multiplicity of animal models of acute stroke. Long-term treatment with citicoline is safe and effective, improving post-stroke cognitive decline and enhancing patients’ functional recovery. Prolonged citicoline administration at optimal doses has been demonstrated to be remarkably well tolerated and to enhance endogenous mechanisms of neurogenesis and neurorepair contributing to physical therapy and rehabilitation. PMID:24961534

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

FY04 LDRD Final Report Stroke Sensor Development Using Microdot Sensor Arrays

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

Carter, J C; Wilson, T S; Alvis, R M

2005-11-15

Stroke is a major cause of mortality and is the primary cause of long-term disability in the United States. A recent study of Stroke incidence, using conservative calculations, suggests that over 700,000 people annually in this country will have a stroke. Of these 700,000, approximately 150,000 will die and 400,000 will be left with a significant deficit; only one quarter will return to an independent--although not necessarily baseline--level of functioning. The costs of caring for victims of stroke in the acute phase, chronic care, and lost productivity amount to 40 billion per year. Of all strokes, approximately 20% are hemorrhagicmore » and 20% are due to small vessel disease. Thus, the number of people with large vessel thromboembolic disease and the target population of this research is greater than 400,000. Currently, the only approved therapy for treatment of acute ischemic stroke is intravenous thrombolytic drugs. While stroke patients who receive these drugs are more likely to have better outcomes than those who do not, their improvement is highly dependent on the initiation of treatment within three hours of the onset of symptoms, with an increased risk of intracranial hemorrhage if the medication is begun outside this time window. With this rigid temporal limitation, and with the concern over intracranial hemorrhage, only 2-3% of people with acute stroke are currently being treated by these means. There is ongoing research for a second treatment methodology involving the use of mechanical devices for removing the thrombus (clot) in stroke victims. Two recent reports of a mechanical removal of thrombus, with subsequent improved patient outcome, highlight the potential of this developing technology. Researchers in the MTP are responsible for one of the photomechanical devices under FDA trials. It is conceivable that in the near-term, a second approved therapy for treatment of acute ischemic stroke will involve the mechanical removal of the thrombus. Stroke is a major thrust area for the Medical Technology Program (M-division). Through MTP, LLNL has a sizable investment and recognizable expertise in stroke treatment research. The proposed microdot array sensor for stroke will complement this existing program in which mechanical devices are being designed for removing the thrombus. The following list of stroke projects and their relative status shows that MTP has a proven track record of taking ideas to industry: The goal of this LDRD funded project was to develop and demonstrate a minimally invasive optical fiber-based sensor for rapid and in-vivo measurements of multiple stroke biomarkers (e.g. pH and enzyme). The development of this sensor also required the development of a new fabrication technology for attaching indicator chemistries to optical fibers. A benefit of this work is to provide clinicians with a tool to assess vascular integrity of the region beyond the thrombus to determine whether or not it is safe to proceed with the removal of the clot. Such an assessment could extend the use of thrombolytic drug treatment to acute stroke victims outside the current rigid temporal limitation of 3 hours. Furthermore, this sensor would also provide a tool for use with emerging treatments involving the use of mechanical devices for removing the thrombus. The sensor effectively assesses the risk for reperfusion injury.« less

Lightning Magnetic Field Measurements around Langmuir Laboratory

NASA Astrophysics Data System (ADS)

Stock, M.; Krehbiel, P. R.; Rison, W.; Aulich, G. D.; Edens, H. E.; Sonnenfeld, R. G.

2010-12-01

In the absence of artificial conductors, underground lightning transients are produced by diffusion of the horizontal surface magnetic field of a return stroke vertically downward into the conducting earth. The changing magnetic flux produces an orthogonal horizontal electric field, generating a dispersive, lossy transverse electromagnetic wave that penetrates a hundred meters or more into the ground according to the skin depth of the medium. In turn, the electric field produces currents that flow toward or away from the channel to ground depending on the stroke polarity. The underground transients can produce large radial horizontal potential gradients depending on the distance from the discharge and depth below the surface. In this study we focus on the surface excitation field. The goal of the work is to compare measurements of surface magnetic field waveforms B(t) at different distances from natural lightning discharges with simple and detailed models of the return stroke fields. In addition to providing input to the diffusion mechanism, the results should aid in further understanding return stroke field generation processes. The observational data are to be obtained using orthogonal sets of straightened Rogowski coils to measure magnetic field waveforms in N-S and E-W directions. The waveforms are sampled at 500 kS/s over 1.024 second time intervals and recorded directly onto secure digital cards. The instrument operates off of battery power for several days or weeks at a time in remote, unattended locations and measures magnetic field strengths of up to several tens of amperes/meter. The observations are being made in conjunction with collocated slow electric field change measurements and under good 3-D lightning mapping array (LMA) and fast electric field change coverage.

Relapse of Takayasu arteritis as a cause of suicidal poisoning and subsequent major ischemic stroke successfully treated with thrombolytic therapy.

PubMed

Komatina, Neneal; Lepić, Toplica; Labović, Boban; Stevović, Tatjana; Petronijević, Milan; Radovinović-Tasić, Sanja; Obradović, Dragana

2016-08-01

Takayasu arteritis (TA) is a rare large vessel arteritis, affecting primarily aorta and its major branches. Its clinical manifestations can vary significantly - from asymptomatic to serious vascular events. Acute neurological complications are frequent at the onset of the disease and in relapses. Anxiety and depression are more frequent in TA patients than in general population as well as during relapses. Prevalence of transient ischemic attack or ischemic stroke in TA patients is approximately 10-20%. We presented a patient with TA that began with a depressive episode resulting in attempted suicide by bromazepame poisoning. This was subsequently followed by major ischemic stroke caused by thrombosis of the left middle cerebral artery (probably due to aortic arch embolism) successfully treated with intravenous thrombolysis. Intravenous thrombolysis appears to be safe and effective in patients with TA and stroke.

Recurrent transient ischaemic attack and early risk of stroke: data from the PROMAPA study.

PubMed

Purroy, Francisco; Jiménez Caballero, Pedro Enrique; Gorospe, Arantza; Torres, María José; Alvarez-Sabin, José; Santamarina, Estevo; Martínez-Sánchez, Patricia; Cánovas, David; Freijo, María José; Egido, Jose Antonio; Ramírez-Moreno, Jose M; Alonso-Arias, Arantza; Rodríguez-Campello, Ana; Casado, Ignacio; Delgado-Mederos, Raquel; Martí-Fàbregas, Joan; Fuentes, Blanca; Silva, Yolanda; Quesada, Helena; Cardona, Pere; Morales, Ana; de la Ossa, Natalia Pérez; García-Pastor, Antonio; Arenillas, Juan F; Segura, Tomas; Jiménez, Carmen; Masjuán, Jaime

2013-06-01

Many guidelines recommend urgent intervention for patients with two or more transient ischaemic attacks (TIAs) within 7 days (multiple TIAs) to reduce the early risk of stroke. To determine whether all patients with multiple TIAs have the same high early risk of stroke. Between April 2008 and December 2009, we included 1255 consecutive patients with a TIA from 30 Spanish stroke centres (PROMAPA study). We prospectively recorded clinical characteristics. We also determined the short-term risk of stroke (at 7 and 90 days). Aetiology was categorised using the TOAST (Trial of Org 10172 in Acute Stroke Treatment) classification. Clinical variables and extracranial vascular imaging were available and assessed in 1137/1255 (90.6%) patients. 7-Day and 90-day stroke risk were 2.6% and 3.8%, respectively. Large-artery atherosclerosis (LAA) was confirmed in 190 (16.7%) patients. Multiple TIAs were seen in 274 (24.1%) patients. Duration <1 h (OR=2.97, 95% CI 2.20 to 4.01, p<0.001), LAA (OR=1.92, 95% CI 1.35 to 2.72, p<0.001) and motor weakness (OR=1.37, 95% CI 1.03 to 1.81, p=0.031) were independent predictors of multiple TIAs. The subsequent risk of stroke in these patients at 7 and 90 days was significantly higher than the risk after a single TIA (5.9% vs 1.5%, p<0.001 and 6.8% vs 3.0%, respectively). In the logistic regression model, among patients with multiple TIAs, no variables remained as independent predictors of stroke recurrence. According to our results, multiple TIAs within 7 days are associated with a greater subsequent risk of stroke than after a single TIA. Nevertheless, we found no independent predictor of stroke recurrence among these patients.

A systematic review investigating fatigue, psychological and cognitive impairment following TIA and minor stroke: protocol paper.

PubMed

Moran, Grace M; Fletcher, Benjamin; Calvert, Melanie; Feltham, Max G; Sackley, Catherine; Marshall, Tom

2013-09-08

Approximately 20,000 people have a transient ischemic attack (TIA) and 23,375 have a minor stroke in England each year. Fatigue, psychological and cognitive impairments are well documented post-stroke. Evidence suggests that TIA and minor stroke patients also experience these impairments; however, they are not routinely offered relevant treatment. This systematic review aims to: (1) establish the prevalence of fatigue, anxiety, depression, post-traumatic stress disorder (PTSD) and cognitive impairment following TIA and minor stroke and to investigate the temporal course of these impairments; (2) explore impact on quality of life (QoL), change in emotions and return to work; (3) identify where further research is required and to potentially inform an intervention study. A systematic review of MEDLINE, EMBASE, PsycINFO, CINAHL, Cochrane libraries and grey literature between January 1993 and April 2013 will be undertaken. Two reviewers will conduct screening search results, study selection, data extraction and quality assessment. Studies of adult TIA and minor stroke participants containing any of the outcomes of interest; fatigue, anxiety, depression, PTSD or cognitive impairment will be included. Studies at any time period after TIA/minor stroke, including those with any length of follow-up, will be included to investigate the temporal course of impairments. QoL, change in emotions and return to work will also be documented. The proportion of TIA or minor stroke participants experiencing each outcome will be reported.If appropriate, a meta-analysis will pool results of individual outcomes. Studies will be grouped and analyzed according to their follow-up timeframe into short-term (< 3 months after TIA/minor stroke), medium-term (3 to 12 months) and long term (> 12 months). Sub-analysis of studies with a suitable control group will be conducted. Exploratory sub-analysis of memory and attention domains of cognitive impairment will be conducted. The current treatment goal for TIA and minor stroke patients is secondary stroke prevention. If these patients do experience fatigue, psychological or cognitive impairments then this treatment alone is unlikely to be sufficient. The results of this comprehensive review will increase understanding of treatment needs for this patient group, identify where further research is required and potentially inform an intervention trial.

Contemporary Trends and Predictors of Postacute Service Use and Routine Discharge Home After Stroke

PubMed Central

Prvu Bettger, Janet; McCoy, Lisa; Smith, Eric E.; Fonarow, Gregg C.; Schwamm, Lee H.; Peterson, Eric D.

2015-01-01

Background Returning home after the hospital is a primary aim for healthcare; however, additional postacute care (PAC) services are sometimes necessary for returning stroke patients to their pre‐event status. Recent trends in hospital discharge disposition specifying PAC use have not been examined across age groups or health insurance types. Methods and Results We examined trends in discharge to inpatient rehabilitation facilities (IRFs), skilled nursing facilities (SNFs), home with home health (HH), and home without services for 849 780 patients ≥18 years of age with ischemic or hemorrhagic stroke at 1687 hospitals participating in Get With The Guidelines—Stroke. Multivariable analysis was used to identify factors associated with discharge to any PAC (IRF, SNF, or HH) versus discharge home without services. From 2003 to 2011, there was a 2.1% increase (unadjusted P=0.001) in PAC use after a stroke hospitalization. Change was greatest in SNF use, an 8.3% decrease over the period. IRF and HH increased 6.9% and 3.6%, respectively. The 2 strongest clinical predictors of PAC use after acute care were patients not ambulating on the second day of their hospital stay (ambulation odds ratio [OR], 3.03; 95% confidence interval [CI], 2.86 to 3.23) and those who failed a dysphagia screen or had an order restricting oral intake (OR, 2.48; 95% CI, 2.37 to 2.59). Conclusions Four in 10 stroke patients are discharged home without services. Although little has changed overall in PAC use since 2003, further research is needed to explain the shift in service use by type and its effect on outcomes. PMID:25713291

Contemporary trends and predictors of postacute service use and routine discharge home after stroke.

PubMed

Prvu Bettger, Janet; McCoy, Lisa; Smith, Eric E; Fonarow, Gregg C; Schwamm, Lee H; Peterson, Eric D

2015-02-23

Returning home after the hospital is a primary aim for healthcare; however, additional postacute care (PAC) services are sometimes necessary for returning stroke patients to their pre-event status. Recent trends in hospital discharge disposition specifying PAC use have not been examined across age groups or health insurance types. We examined trends in discharge to inpatient rehabilitation facilities (IRFs), skilled nursing facilities (SNFs), home with home health (HH), and home without services for 849 780 patients ≥18 years of age with ischemic or hemorrhagic stroke at 1687 hospitals participating in Get With The Guidelines-Stroke. Multivariable analysis was used to identify factors associated with discharge to any PAC (IRF, SNF, or HH) versus discharge home without services. From 2003 to 2011, there was a 2.1% increase (unadjusted P=0.001) in PAC use after a stroke hospitalization. Change was greatest in SNF use, an 8.3% decrease over the period. IRF and HH increased 6.9% and 3.6%, respectively. The 2 strongest clinical predictors of PAC use after acute care were patients not ambulating on the second day of their hospital stay (ambulation odds ratio [OR], 3.03; 95% confidence interval [CI], 2.86 to 3.23) and those who failed a dysphagia screen or had an order restricting oral intake (OR, 2.48; 95% CI, 2.37 to 2.59). Four in 10 stroke patients are discharged home without services. Although little has changed overall in PAC use since 2003, further research is needed to explain the shift in service use by type and its effect on outcomes. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

The NASA Lightning Nitrogen Oxides Model (LNOM): Recent Updates and Applications

NASA Technical Reports Server (NTRS)

Koshak, William; Peterson, Harold; Biazar, Arastoo; Khan, Maudood; Wang, Lihua; Park, Yee-Hun

2011-01-01

Improvements to the NASA Marshall Space Flight Center Lightning Nitrogen Oxides Model (LNOM) and its application to the Community Multiscale Air Quality (CMAQ) modeling system are presented. The LNOM analyzes Lightning Mapping Array (LMA) and National Lightning Detection Network(tm) (NLDN) data to estimate the raw (i.e., unmixed and otherwise environmentally unmodified) vertical profile of lightning NOx (= NO + NO2). Lightning channel length distributions and lightning 10-m segment altitude distributions are also provided. In addition to NOx production from lightning return strokes, the LNOM now includes non-return stroke lightning NOx production due to: hot core stepped and dart leaders, stepped leader corona sheath, K-changes, continuing currents, and M-components. The impact of including LNOM-estimates of lightning NOx for an August 2006 run of CMAQ is discussed.

Test of the principle of operation of a wideband magnetic direction finder for lightning return strokes

NASA Technical Reports Server (NTRS)

Herrman, B. D.; Uman, M. A.; Brantley, R. D.; Krider, E. P.

1976-01-01

The principle of operation of a wideband crossed-loop magnetic-field direction finder is studied by comparing the bearing determined from the NS and EW magnetic fields at various times up to 155 microsec after return stroke initiation with the TV-determined lightning channel base direction. For 40 lightning strokes in the 3 to 12 km range, the difference between the bearings found from magnetic fields sampled at times between 1 and 10 microsec and the TV channel-base data has a standard deviation of 3-4 deg. Included in this standard deviation is a 2-3 deg measurement error. For fields sampled at progressively later times, both the mean and the standard deviation of the difference between the direction-finder bearing and the TV bearing increase. Near 150 microsec, means are about 35 deg and standard deviations about 60 deg. The physical reasons for the late-time inaccuracies in the wideband direction finder and the occurrence of these effects in narrow-band VLF direction finders are considered.

Rare variants of the 3’-5’ DNA exonuclease TREX1 in early onset small vessel stroke

PubMed Central

McGlasson, Sarah; Rannikmäe, Kristiina; Bevan, Steven; Logan, Clare; Bicknell, Louise S.; Jury, Alexa; Jackson, Andrew P.

2017-01-01

Background: Monoallelic and biallelic mutations in the exonuclease TREX1 cause monogenic small vessel diseases (SVD). Given recent evidence for genetic and pathophysiological overlap between monogenic and polygenic forms of SVD, evaluation of TREX1 in small vessel stroke is warranted. Methods: We sequenced the TREX1 gene in an exploratory cohort of patients with lacunar stroke (Edinburgh Stroke Study, n=290 lacunar stroke cases). We subsequently performed a fully blinded case-control study of early onset MRI-confirmed small vessel stroke within the UK Young Lacunar Stroke Resource (990 cases, 939 controls). Results: No patients with canonical disease-causing mutations of TREX1 were identified in cases or controls. Analysis of an exploratory cohort identified a potential association between rare variants of TREX1 and patients with lacunar stroke. However, subsequent controlled and blinded evaluation of TREX1 in a larger and MRI-confirmed patient cohort, the UK Young Lacunar Stroke Resource, identified heterozygous rare variants in 2.1% of cases and 2.3% of controls. No association was observed with stroke risk (odds ratio = 0.90; 95% confidence interval, 0.49-1.65 p=0.74). Similarly no association was seen with rare TREX1 variants with predicted deleterious effects on enzyme function (odds ratio = 1.05; 95% confidence interval, 0.43-2.61 p=0.91). Conclusions: No patients with early-onset lacunar stroke had genetic evidence of a TREX1-associated monogenic microangiopathy. These results show no evidence of association between rare variants of TREX1 and early onset lacunar stroke. This includes rare variants that significantly affect protein and enzyme function. Routine sequencing of the TREX1 gene in patients with early onset lacunar stroke is therefore unlikely to be of diagnostic utility, in the absence of syndromic features or family history. PMID:29387804

Telmisartan to prevent recurrent stroke and cardiovascular events.

PubMed

Yusuf, Salim; Diener, Hans-Christoph; Sacco, Ralph L; Cotton, Daniel; Ounpuu, Stephanie; Lawton, William A; Palesch, Yuko; Martin, Reneé H; Albers, Gregory W; Bath, Philip; Bornstein, Natan; Chan, Bernard P L; Chen, Sien-Tsong; Cunha, Luis; Dahlöf, Björn; De Keyser, Jacques; Donnan, Geoffrey A; Estol, Conrado; Gorelick, Philip; Gu, Vivian; Hermansson, Karin; Hilbrich, Lutz; Kaste, Markku; Lu, Chuanzhen; Machnig, Thomas; Pais, Prem; Roberts, Robin; Skvortsova, Veronika; Teal, Philip; Toni, Danilo; VanderMaelen, Cam; Voigt, Thor; Weber, Michael; Yoon, Byung-Woo

2008-09-18

Prolonged lowering of blood pressure after a stroke reduces the risk of recurrent stroke. In addition, inhibition of the renin-angiotensin system in high-risk patients reduces the rate of subsequent cardiovascular events, including stroke. However, the effect of lowering of blood pressure with a renin-angiotensin system inhibitor soon after a stroke has not been clearly established. We evaluated the effects of therapy with an angiotensin-receptor blocker, telmisartan, initiated early after a stroke. In a multicenter trial involving 20,332 patients who recently had an ischemic stroke, we randomly assigned 10,146 to receive telmisartan (80 mg daily) and 10,186 to receive placebo. The primary outcome was recurrent stroke. Secondary outcomes were major cardiovascular events (death from cardiovascular causes, recurrent stroke, myocardial infarction, or new or worsening heart failure) and new-onset diabetes. The median interval from stroke to randomization was 15 days. During a mean follow-up of 2.5 years, the mean blood pressure was 3.8/2.0 mm Hg lower in the telmisartan group than in the placebo group. A total of 880 patients (8.7%) in the telmisartan group and 934 patients (9.2%) in the placebo group had a subsequent stroke (hazard ratio in the telmisartan group, 0.95; 95% confidence interval [CI], 0.86 to 1.04; P=0.23). Major cardiovascular events occurred in 1367 patients (13.5%) in the telmisartan group and 1463 patients (14.4%) in the placebo group (hazard ratio, 0.94; 95% CI, 0.87 to 1.01; P=0.11). New-onset diabetes occurred in 1.7% of the telmisartan group and 2.1% of the placebo group (hazard ratio, 0.82; 95% CI, 0.65 to 1.04; P=0.10). Therapy with telmisartan initiated soon after an ischemic stroke and continued for 2.5 years did not significantly lower the rate of recurrent stroke, major cardiovascular events, or diabetes. (ClinicalTrials.gov number, NCT00153062.) 2008 Massachusetts Medical Society

Dysphagia in Stroke: A New Solution

PubMed Central

Langdon, Claire; Blacker, David

2010-01-01

Dysphagia is extremely common following stroke, affecting 13%–94% of acute stroke sufferers. It is associated with respiratory complications, increased risk of aspiration pneumonia, nutritional compromise and dehydration, and detracts from quality of life. While many stroke survivors experience a rapid return to normal swallowing function, this does not always happen. Current dysphagia treatment in Australia focuses upon prevention of aspiration via diet and fluid modifications, compensatory manoeuvres and positional changes, and exercises to rehabilitate paretic muscles. This article discusses a newer adjunctive treatment modality, neuromuscular electrical stimulation (NMES), and reviews the available literature on its efficacy as a therapy for dysphagia with particular emphasis on its use as a treatment for dysphagia in stroke. There is a good theoretical basis to support the use of NMES as an adjunctive therapy in dysphagia and there would appear to be a great need for further well-designed studies to accurately determine the safety and efficacy of this technique. PMID:20721336

Activity limitations and participation restrictions experienced by people with stroke in Musanze district in Rwanda.

PubMed

Urimubenshi, Gerard

2015-09-01

Stroke is a major cause of long-term disability. Information regarding the limitations in activity and participation experienced by patients with stroke in a specific setting such as Musanze district in Rwanda would assist to develop the rehabilitation programmes that would take into consideration the functional challenges experienced post stroke. To explore the activity limitations and participation restrictions experienced by people with stroke in Musanze district in Rwanda. A qualitative phenomenological approach using in-depth face-to-face interviews with 10 participants was employed to gather the data that was analyzed using a qualitative thematic approach. The themes that arose as activity limitations included limitations in walking, self care, and domestic life activities. The themes related to participation restrictions as expressed by the participants were inability to return to previous occupation, decreased social interactions and inability to participate in religious activities. The current study findings highlight the need for interventions to improve the functional status of stroke survivors.

Increased risks of mortality and atherosclerotic complications in incident hemodialysis patients subsequently with bone fractures: a nationwide case-matched cohort study.

PubMed

Kuo, Chiu-Huang; Hsieh, Tsung-Cheng; Wang, Chih-Hsien; Chou, Chu-Lin; Lai, Yu-Hsien; Chen, Yi-Ya; Lin, Yu-Li; Wu, Sheng-Teng; Fang, Te-Chao

2015-01-01

Hemodialysis (HD) patients with bone fractures have an increased risk for death. However, the risks for mortality and atherosclerotic complications in incident HD patients subsequently with bone fractures are unknown. Data derived from the Taiwan National Health Institute Research Database between January 1997 and December 2008 was analyzed. The enrolled patients included 3,008 incident HD patients subsequently with a single long bone fracture (LB Fx) and 2,070 incident HD patients subsequently with a single non-long bone fracture (NLB Fx). These patients were matched (1:5 ratio) for age, sex, and same duration of HD with incident HD patients who had no fractures and outcomes were measured over a 3-year follow-up. After demographic and co-morbidity adjustment, LB Fx increased the risk for overall mortality (HR = 1.59, p < 0.001) and stroke (HR = 1.09, p = 0.028) in incident HD patients. NLB Fx increased the risk for overall mortality (HR = 1.52, p < 0.001), stroke (HR = 1.19, p < 0.001), coronary artery disease (CAD), (HR = 1.13, p = 0.003), and peripheral arterial occlusive disease (PAOD), (HR = 1.41, p < 0.001) in incident HD patients. Moreover, incident patients subsequently with NLB Fx had significantly higher risks of CAD and PAOD than those subsequently with LB Fx. The rates of mortality and stroke were significantly higher in incident HD patients subsequently with bone fractures than in matched patients without bone fractures. Incident HD patients subsequently with NLB Fx had significantly higher risks of CAD and PAOD than those subsequently with LB Fx and without bone fractures. Thus, incident HD patients subsequently with bone fractures should be closely followed for a higher mortality and possible development of atherosclerotic complications.

Participation in Leisure Activity and Exercise of Chronic Stroke Survivors Using Community-Based Rehabilitation Services in Seongnam City

PubMed Central

Yi, Tae Im; Lee, Ko Eun; Ha, Seung A

2015-01-01

Objective To clarify how participation in leisure activities and exercise by chronic stroke survivors differs before and after a stroke. Methods Sixty chronic stroke survivors receiving community-based rehabilitation services from a health center in Seongnam City were recruited. They completed a questionnaire survey regarding their demographic characteristics and accompanying diseases, and on the status of their leisure activities and exercise. In addition, their level of function (Korean version of Modified Barthel Index score), risk of depression (Beck Depression Inventory), and quality of life (SF-8) were measured. Results After their stroke, most of the respondents had not returned to their pre-stroke levels of leisure activity participation. The reported number of leisure activities declined from a mean of 3.9 activities before stroke to 1.9 activities post-stroke. In addition, many participants became home-bound, sedentary, and non-social after their stroke. The most common barriers to participation in leisure activities were weakness and poor balance, lack of transportation, and cost. The respondents reported a mean daily time spent on exercise of 2.6±1.3 hours. Pain was the most common barrier to exercise participation. Conclusion Chronic stroke survivors need information on leisure activities and appropriate pain management. PMID:25932420

[The education influence on effects of rehabilitation in patients after stroke].

PubMed

Dudka, Sabina; Winczewski, Piotr; Janczewska, Katarzyna; Kubsik, Anna; Woldańska-Okońska, Marta

2016-11-25

Patients after stroke face a new situation where some educational and pedagogical actions should be reinitiated. Stroke often causes a break away from the previous lifestyle. It the acute phase it excludes the possibility of employment or performance of household duties that were carried out before or indulging in previously preferred ways of spending free time. Patients often abandon the habits that they developed before stroke, inclusive of hygienic habits. Therefore, it is an important objective of rehabilitation to reinstate in stroke patients behaviours characteristic of their peers, which would mark the beginning of their own care for health. The pedagogic and educational activities should lead to a transformation in the patient. This could be one of the factors in facilitating the patient's return to previous forms of activity. The aim of this study was to analyze progress in patient's rehabilitation and satisfaction, to assess impact of health education on higher satisfaction and better knowledge in stroke patients as well as on their recovery. Another aim was to assess the factors that maximize the patients' chances of returning to the labor market. The study involved 30 patients after stroke, 8 women and 22 men, over 40 years of age, who underwent either early or late rehabilitation, the type of which affected the time of treatment. The minimal duration of the patient's stay was 21 days, in which time an individually tailored way of education, rehabilitation, treatment and care was implemented. The study used a questionnaire and the Bartel and the Rankin scales. The subject of the analysis consisted of 22 questions that were based on hypotheses. They assessed the facts, the sources of information, knowledge and subjective feelings of the patients concerning the education carried out by the rehabilitation team and its impact on the patients' rehabilitation. A highly significant (p<0,01) improvement to patients' health and an increase in their knowledge were observed in the rehabilitation. During the rehabilitation patients gained a significant improvement to their health, which resulted in more independence in daily living. The implemented health education has an effect on the scope of the patients' knowledge during and after rehabilitation, which translates into a higher satisfaction from the patient's education. The acquired knowledge and skills increase the chances of the patient to return to activities and participation in social life at a satisfactory level. The members of the rehabilitation team, especially the physicians, play an important role in health education of patients.

The Role of Neuroimaging in the Latent Period of Blunt Traumatic Cerebrovascular Injury

PubMed Central

Karamchandani, Rahul; Rajajee, Venkatakrishna; Pandey, Aditya

2011-01-01

Introduction: Blunt cerebrovascular injury (BCVI) is found in 1-2.7% of all blunt trauma when appropriate screening criteria are employed. A significant number of patients with BCVI have a latent, or asymptomatic period, in which therapeutic intervention based on the appropriate use of angiographic imaging may decrease the risk of an ischemic stroke. Methods: Case report and review of literature. Results: A 42 year old woman suffered a fall off a motorcycle and was neurologically intact in the emergency room. Fractures involving the transverse foramen of cervical vertebrae were found on non-contrast Computed Tomography (CT) but screening for BCVI with angiographic imaging not performed. She subsequently suffered an ischemic stroke resulting in significant disability. Published studies that address the use of screening criteria for BCVI and subsequent management are reviewed. Conclusion: BCVI results in significant morbidity and mortality attributable to ischemic stroke. There is often a latent period between BCVI and occurrence of ischemic stroke. Specific risk factors can be used to identify patients requiring screening with catheter or CT angiography. Treatment with antithrombotic agents is the mainstay of treatment of BCVI and may reduce the rate of ischemic stroke. Identification and treatment of asymptomatic BCVI in blunt trauma patients may prevent ischemic stroke in a predominantly young population. PMID:22253664

Individualised home-based rehabilitation after stroke in eastern Finland--the client's perspective.

PubMed

Reunanen, Merja A T; Järvikoski, Aila; Talvitie, Ulla; Pyöriä, Outi; Härkäpää, Kristiina

2016-01-01

Reintegration into society is one of the main purposes of post-stroke rehabilitation. The experiences of clients returning home after a stroke have been studied before. There is, however, little knowledge about activities carried out during home-based rehabilitation interventions and about the involvement of clients in the process. This study focused on clients' experiences of a 3-month individualised, home-based rehabilitation programme supervised by a multidisciplinary team. The data were collected in 2009-2010, and it was based on interviews with 14 clients (48-83 years of age) conducted approximately 7 months after stroke. In the thematic analysis, five main topics describing the goals and functions of the home-based rehabilitation were identified as follows: (i) learning strategies for solving problems in daily activities at home and in the community; (ii) receiving exercise coaching; (iii) exploring community services and facilities; (iv) having a dialogue with professionals; and (v) engaging in activities aimed at returning to work. Implementing rehabilitation activities in the home environment seemed to enhance the participants' active involvement and their ability to evaluate themselves and to set goals for their recovery. Work was an important goal for clients of working age, but work-related tasks were not sufficiently integrated with home-based rehabilitation. A challenge for local communities is to provide health promotion and recreation services that are also suitable for persons with limited functioning. © 2015 John Wiley & Sons Ltd.

Submicrosecond characteristics of lightning return-stroke currents

NASA Technical Reports Server (NTRS)

Leteinturier, Christiane; Hamelin, Joel H.; Eybert-Berard, Andre

1991-01-01

The authors describe the experimental results obtained during 1987 and 1988 triggered-lightning experiments in Florida. Seventy-four simultaneous submicrosecond time-resolved measurements of triggered return-stroke current (I) and current derivative (dI/dt) were made in Florida in 1987 and 1988. Peak currents ranged from about 5 to 76 kA, peak dI/dt amplitude from 13 to 411 kA/microsec and rise time from 90 to 1000 ns. The mean peak dI/dt values of 110 kA/microsec were 2-3 times higher than data from instrumented towers and peak I and dI/dt appear to be positively correlated. These data confirm previous experiments and conclusions supported by forty measurements. They are important in order to define, for example, standards for lightning protection. Present standards give a dI/dt maximum of 140 kA/microsec.

Milrinone ameliorates cardiac mechanical dysfunction after hypothermia in an intact rat model.

PubMed

Dietrichs, Erik Sveberg; Kondratiev, Timofei; Tveita, Torkjel

2014-12-01

Rewarming from hypothermia is often complicated by cardiac dysfunction, characterized by substantial reduction in stroke volume. Previously we have reported that inotropic agents, working via cardiac β-receptor agonism may exert serious side effects when applied to treat cardiac contractile dysfunction during rewarming. In this study we tested whether Milrinone, a phosphodiesterase III inhibitor, is able to ameliorate such dysfunction when given during rewarming. A rat model designed for circulatory studies during experimental hypothermia with cooling to a core temperature of 15°C, stable hypothermia at this temperature for 3h and subsequent rewarming was used, with a total of 3 groups: (1) a normothermic group receiving Milrinone, (2) a hypothermic group receiving Milrinone the last hour of hypothermia and during rewarming, and (3) a hypothermic saline control group. Hemodynamic function was monitored using a conductance catheter introduced to the left ventricle. After rewarming from 15°C, stroke volume and cardiac output returned to within baseline values in Milrinone treated animals, while these variables were significantly reduced in saline controls. Milrinone ameliorated cardiac dysfunction during rewarming from 15°C. The present results suggest that at low core temperatures and during rewarming from such temperatures, pharmacologic efforts to support cardiovascular function is better achieved by substances preventing cyclic AMP breakdown rather than increasing its formation via β-receptor stimulation. Copyright © 2014 Elsevier Inc. All rights reserved.

Factors associated with community reintegration in the first year after stroke: a qualitative meta-synthesis.

PubMed

Walsh, Mary E; Galvin, Rose; Loughnane, Cliona; Macey, Chris; Horgan, N Frances

2015-01-01

Although acute stroke care has improved survival, many individuals report dissatisfaction with community reintegration after stroke. The aim of this qualitative meta-synthesis was to examine the barriers and facilitators of community reintegration in the first year after stroke from the perspective of people with stroke. A systematic literature search was conducted. Papers that used qualitative methods to explore the experiences of individuals with stroke around community reintegration in the first year after stroke were included. Two reviewers independently assessed the methodological quality of papers. Themes, concepts and interpretations were extracted from each study, compared and meta-synthesised. From the 18 included qualitative studies four themes related to community reintegration in the first year after stroke were identified: (i) the primary effects of stroke, (ii) personal factors, (iii) social factors and (iv) relationships with professionals. This review suggests that an individual's perseverance, adaptability and ability to overcome emotional challenges can facilitate reintegration into the community despite persisting effects of their stroke. Appropriate support from family, friends, the broader community and healthcare professionals is important. Therapeutic activities should relate to meaningful activities and should be tailored to the individual stroke survivor. Stroke survivors feel that rehabilitation in familiar environments and therapeutic activities that reflect real-life could help their community re-integration. In addition to the physical sequelae of stroke, emotional consequences of stroke should be addressed during rehabilitation. Healthcare professionals can provide clear and locally relevant advice to facilitate aspects of community reintegration, including the return to driving and work.

Rethinking the continuum of stroke rehabilitation.

PubMed

Teasell, Robert W; Murie Fernandez, Manuel; McIntyre, Amanda; Mehta, Swati

2014-04-01

Suffering a stroke can be a devastating and life-changing event. Although there is a large evidence base for stroke rehabilitation in the acute and subacute stages, it has been long accepted that patients with stroke reach a plateau in their rehabilitation recovery relatively early. We have recently published the results of a systematic review designed to identify all randomized controlled trials (RCTs) where a rehabilitation intervention was initiated more than 6 months after the onset of the stroke. Of the trials identified, 339 RCTs met inclusion criteria, demonstrating an evidence base for stroke rehabilitation in the chronic phase as well. This seems at odds with the assumption that further recovery is unlikely and the subsequent lack of resources devoted to chronic stroke rehabilitation and management. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Preferential location for arterial dissection presenting as golf-related stroke.

PubMed

Choi, M H; Hong, J M; Lee, J S; Shin, D H; Choi, H A; Lee, K

2014-02-01

Golf-related stroke has not been systematically reviewed. The purpose of our study was to describe in detail this particular stroke syndrome. Seven patients were analyzed at a university hospital and 7 patients were reviewed from MEDLINE literature. General demographics, symptom onset, neurologic signs, radiologic findings, and outcome were investigated. A total of 14 patients including 7 patients from the MEDLINE search were analyzed; all were men, with a mean age of 46.9 ± 12.8 years. Symptom onset was classified as during the golf swing (n = 9), unknown (n = 3), and after playing golf (n = 2). Most patients (n = 12) showed involvement of the vertebral artery and 2 patients showed involvement of the internal carotid artery (P = .008). Nine dissections were found on the right side, 3 on the left side, and 2 were bilateral (P = .046). Twelve patients had extracranial involvement and 2 patients had intracranial involvement (P = .008). Seven patients returned to normal, 5 returned to independence, 1 had unknown status, and 1 died. The anatomic preference of golf-related craniocervical arterial dissection is associated with the extracranial and vertebrobasilar system with a right-sided tendency as the result of stereotypical rotational movement during a golf swing.

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.

American College of Sports Medicine Roundtable on Exertional Heat Stroke - Return to Duty/Return to Play: Conference Proceedings

DTIC Science & Technology

2010-01-01

individuals with EHS experience long-term complica- tions that may include multisystem organ (liver, kidney, muscle ) and neurologic damage, as well as... reduced exercise capacity and heat intolerance (12,52,57,69). Animal and human research suggest late or untreated EHS may result in organ damage that...collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and

Stroke unit care benefits patients with intracerebral hemorrhage: systematic review and meta-analysis.

PubMed

Langhorne, Peter; Fearon, Patricia; Ronning, Ole M; Kaste, Markku; Palomaki, Heikki; Vemmos, Kostos; Kalra, Lalit; Indredavik, Bent; Blomstrand, Christian; Rodgers, Helen; Dennis, Martin S; Al-Shahi Salman, Rustam

2013-11-01

Patients with any type of stroke managed in organized inpatient (stroke unit) care are more likely to survive, return home, and regain independence. However, it is uncertain whether these benefits apply equally to patients with intracerebral hemorrhage and ischemic stroke. We conducted a secondary analysis of a systematic review of controlled clinical trials comparing stroke unit care with general ward care, including only trials published after 1990 that could separately report outcomes for patients with intracerebral hemorrhage and ischemic stroke. We performed random-effects meta-analyses and tested for subgroup interactions by stroke type. We identified 13 trials (3570 patients) of modern stroke unit care that recruited patients with intracerebral hemorrhage and ischemic stroke, of which 8 trials provided data on 2657 patients. Stroke unit care reduced death or dependency (risk ratio [RR], 0.81; 95% confidence interval [CI], 0.471-0.92; P=0.0009; I2=60%) with no difference in benefits for patients with intracerebral hemorrhage (RR, 0.79; 95% CI, 0.61-1.00) than patients with ischemic stroke (RR, 0.82; 95% CI, 0.70-0.97; Pinteraction=0.77). Stroke unit care reduced death (RR, 0.79; 95% CI, 0.64-0.97; P=0.02; I2=49%) to a greater extent for patients with intracerebral hemorrhage (RR, 0.73; 95% CI, 0.54-0.97) than patients with ischemic stroke (RR, 0.82; 95%, CI 0.61-1.09), but this difference was not statistically significant (Pinteraction=0.58). Patients with intracerebral hemorrhage seem to benefit at least as much as patients with ischemic stroke from organized inpatient (stroke unit) care.

Initial testing of a variable-stroke Stirling engine

NASA Technical Reports Server (NTRS)

Thieme, L. G.

1985-01-01

In support of the U.S. Department of Energy's Stirling Engine Highway Vehicle Systems Program, NASA Lewis Research Center is evaluating variable-stroke control for Stirling engines. The engine being tested is the Advenco Stirling engine; this engine was manufactured by Philips Research Laboratories of the Netherlands and uses a variable-angle swash-plate drive to achieve variable stroke operation. The engine is described, initial steady-state test data taken at Lewis are presented, a major drive system failure and subsequent modifications are described. Computer simulation results are presented to show potential part-load efficiency gains with variable-stroke control.

Rehabilitation of Motor Function after Stroke: A Multiple Systematic Review Focused on Techniques to Stimulate Upper Extremity Recovery

PubMed Central

Hatem, Samar M.; Saussez, Geoffroy; della Faille, Margaux; Prist, Vincent; Zhang, Xue; Dispa, Delphine; Bleyenheuft, Yannick

2016-01-01

Stroke is one of the leading causes for disability worldwide. Motor function deficits due to stroke affect the patients' mobility, their limitation in daily life activities, their participation in society and their odds of returning to professional activities. All of these factors contribute to a low overall quality of life. Rehabilitation training is the most effective way to reduce motor impairments in stroke patients. This multiple systematic review focuses both on standard treatment methods and on innovating rehabilitation techniques used to promote upper extremity motor function in stroke patients. A total number of 5712 publications on stroke rehabilitation was systematically reviewed for relevance and quality with regards to upper extremity motor outcome. This procedure yielded 270 publications corresponding to the inclusion criteria of the systematic review. Recent technology-based interventions in stroke rehabilitation including non-invasive brain stimulation, robot-assisted training, and virtual reality immersion are addressed. Finally, a decisional tree based on evidence from the literature and characteristics of stroke patients is proposed. At present, the stroke rehabilitation field faces the challenge to tailor evidence-based treatment strategies to the needs of the individual stroke patient. Interventions can be combined in order to achieve the maximal motor function recovery for each patient. Though the efficacy of some interventions may be under debate, motor skill learning, and some new technological approaches give promising outcome prognosis in stroke motor rehabilitation. PMID:27679565

Electromagnetic fields radiated from a lightning return stroke - Application of an exact solution to Maxwell's equations

NASA Technical Reports Server (NTRS)

Le Vine, D. M.; Meneghini, R.

1978-01-01

A solution is presented for the electromagnetic fields radiated by an arbitrarily oriented current filament over a conducting ground plane in the case where the current propagates along the filament at the speed of light, and this solution is interpreted in terms of radiation from lightning return strokes. The solution is exact in the fullest sense; no mathematical approximations are made, and the governing differential equations and boundary conditions are satisfied. The solution has the additional attribute of being specified in closed form in terms of elementary functions. This solution is discussed from the point of view of deducing lightning current wave forms from measurements of the electromagnetic fields and understanding the effects of channel tortuosity on the radiated fields. In addition, it is compared with two approximate solutions, the traditional moment approximation and the Fraunhofer approximation, and a set of criteria describing their applicability are presented and interpreted.

Why Flash Type Matters: A Statistical Analysis

NASA Astrophysics Data System (ADS)

Mecikalski, Retha M.; Bitzer, Phillip M.; Carey, Lawrence D.

2017-09-01

While the majority of research only differentiates between intracloud (IC) and cloud-to-ground (CG) flashes, there exists a third flash type, known as hybrid flashes. These flashes have extensive IC components as well as return strokes to ground but are misclassified as CG flashes in current flash type analyses due to the presence of a return stroke. In an effort to show that IC, CG, and hybrid flashes should be separately classified, the two-sample Kolmogorov-Smirnov (KS) test was applied to the flash sizes, flash initiation, and flash propagation altitudes for each of the three flash types. The KS test statistically showed that IC, CG, and hybrid flashes do not have the same parent distributions and thus should be separately classified. Separate classification of hybrid flashes will lead to improved lightning-related research, because unambiguously classified hybrid flashes occur on the same order of magnitude as CG flashes for multicellular storms.

Simulation of radiation from lightning return strokes - The effects of tortuosity

NASA Technical Reports Server (NTRS)

Levine, D. M.; Meneghini, R.

1978-01-01

A Monte Carlo simulation has been developed for the electromagnetic fields radiated from a tortuous lightning channel. This was done using a piecewise linear model for the channel and employing for each element the field radiated by a traveling wave on an arbitrarily oriented filament over a conducting plane. The simulation reproduces experimental data reasonably well and has been used to study the effects of tortuosity on the fields radiated by return strokes. Tortuosity can significantly modify the radiated waveform, tending to render it less representative of the current pulse and more nearly unipolar than one would expect based on the theory for a long straight channel. In the frequency domain the effect of tortuosity is an increase in high frequency energy as compared with an equivalent straight channel. The extent of this increase depends on the mean length of the elements comprising the channel and can be significant.

Drift stabilizer for reciprocating free-piston devices

DOEpatents

Ward, William C.; Corey, John A.; Swift, Gregory W.

2003-05-20

A free-piston device has a stabilized piston drift. A piston having a frequency of reciprocation over a stroke length and with first and second sides facing first and second variable volumes, respectively, for containing a working fluid defining an acoustic wavelength at the frequency of reciprocation. A bypass tube waveguide connects the first and second variable volumes at all times during reciprocation of the piston. The waveguide has a relatively low impedance for steady flow and a relatively high impedance for oscillating flow at the frequency of reciprocation of the piston, so that steady flow returns fluid leakage from about the piston between the first and second volumes while oscillating flow is not diverted through the waveguide. Thus, net leakage about the piston is returned during each stroke of the piston while oscillating leakage is not allowed and pressure buildup on either the first or second side of the piston is avoided to provide a stable piston location.

Increased Risks of Mortality and Atherosclerotic Complications in Incident Hemodialysis Patients Subsequently with Bone Fractures: A Nationwide Case-Matched Cohort Study

PubMed Central

Kuo, Chiu-Huang; Hsieh, Tsung-Cheng; Wang, Chih-Hsien; Chou, Chu-Lin; Lai, Yu-Hsien; Chen, Yi-Ya; Lin, Yu-Li; Wu, Sheng-Teng; Fang, Te-Chao

2015-01-01

Background Hemodialysis (HD) patients with bone fractures have an increased risk for death. However, the risks for mortality and atherosclerotic complications in incident HD patients subsequently with bone fractures are unknown. Methods Data derived from the Taiwan National Health Institute Research Database between January 1997 and December 2008 was analyzed. The enrolled patients included 3,008 incident HD patients subsequently with a single long bone fracture (LB Fx) and 2,070 incident HD patients subsequently with a single non-long bone fracture (NLB Fx). These patients were matched (1:5 ratio) for age, sex, and same duration of HD with incident HD patients who had no fractures and outcomes were measured over a 3-year follow-up. Results After demographic and co-morbidity adjustment, LB Fx increased the risk for overall mortality (HR = 1.59, p < 0.001) and stroke (HR = 1.09, p = 0.028) in incident HD patients. NLB Fx increased the risk for overall mortality (HR = 1.52, p < 0.001), stroke (HR = 1.19, p < 0.001), coronary artery disease (CAD), (HR = 1.13, p = 0.003), and peripheral arterial occlusive disease (PAOD), (HR = 1.41, p < 0.001) in incident HD patients. Moreover, incident patients subsequently with NLB Fx had significantly higher risks of CAD and PAOD than those subsequently with LB Fx. Conclusions The rates of mortality and stroke were significantly higher in incident HD patients subsequently with bone fractures than in matched patients without bone fractures. Incident HD patients subsequently with NLB Fx had significantly higher risks of CAD and PAOD than those subsequently with LB Fx and without bone fractures. Thus, incident HD patients subsequently with bone fractures should be closely followed for a higher mortality and possible development of atherosclerotic complications. PMID:25874794

Is Transient Ischemic Attack a Medical Emergency? An Evidence-Based Analysis

PubMed Central

Sehatzadeh, S

2015-01-01

Background Transient ischemic attack (TIA) is a brief episode of dysfunction in a confined area of the brain. The risk of stroke following TIA is approximately 4% within the first 2 days and 9% within the first month. Therefore, early diagnosis and treatment is critical to reduce mortality and risk of stroke in patients who have experienced a TIA. Objectives This systematic review aimed to investigate the impact of the urgent evaluation and initiation of treatment of patients with TIA on the risk of subsequent stroke and death. Data Sources A literature search was performed for studies published from January 1, 2007, until December 21, 2012. The search was updated monthly to April 1, 2013. Results All identified studies showed that urgent assessment and initiation of treatment of TIA is an effective strategy in reducing the incidence of stroke. Among these, a large observational study found a large effect in that the risk of stroke was reduced by 80%, and a Canadian study found that providing urgent care significantly reduced the rate of stroke in high-risk patients. Another Canadian study reported a significant reduction in the rate of death among patients referred to stroke prevention clinics, compared to patients not referred to such services. One study showed that patients discharged from an emergency department with standard care had significantly higher rates of stroke and subsequent TIA in the first month, compared to those who were hospitalized. However, another study showed that for patients at low to moderate risk, rate of stroke was similar between inpatients and those managed in a TIA clinic. Limitations Our analysis was restricted to the effect of the combined interventions. The magnitude of benefit of each individual component of the intervention cannot be determined through this review. Conclusions The results of this systematic review have important clinical and health system implications. Urgent management of TIA patients in specialized TIA clinics rather than regular practice results in a lower rate of stroke and disability. PMID:26355823

The impact of stroke on world leaders.

PubMed

Brickfield, F X; Pyenson, L R

2001-03-01

Earlier studies by our unit documented frequent disability in world leaders resulting from stroke but did not quantify the incidence of cerebrovascular accidents. We sought to identify the frequency and impact of strokes in world leaders. Using various sources, we identified world leaders who had sustained strokes while in office from 1970 to 1999 and tabulated information on symptoms and subsequent ability to lead. Twenty leaders were identified who had sustained strokes during the study period, for an incidence of 0.444 strokes/100 leaders/year. Half of the affected leaders lost their political power within the year; most had persistent disabilities, which included motor, speech, cognitive, and emotional deficits. Strokes in world leaders may be slightly less common than expected based on studies of Western populations of similar age, but they are often devastating to a political career. Nonetheless, loss of political power is not inevitable.

Effect of Hemodynamics on Stroke Risk in Symptomatic Atherosclerotic Vertebrobasilar Occlusive Disease.

PubMed

Amin-Hanjani, Sepideh; Pandey, Dilip K; Rose-Finnell, Linda; Du, Xinjian; Richardson, DeJuran; Thulborn, Keith R; Elkind, Mitchell S V; Zipfel, Gregory J; Liebeskind, David S; Silver, Frank L; Kasner, Scott E; Aletich, Victor A; Caplan, Louis R; Derdeyn, Colin P; Gorelick, Philip B; Charbel, Fady T

2016-02-01

Atherosclerotic vertebrobasilar (VB) occlusive disease is a significant etiology of posterior circulation stroke, with regional hypoperfusion as an important potential contributor to stroke risk. To test the hypothesis that, among patients with symptomatic VB stenosis or occlusion, those with distal blood flow compromise as measured by large-vessel quantitative magnetic resonance angiography (QMRA) are at higher risk of subsequent posterior circulation stroke. A prospective, blinded, longitudinal cohort study was conducted at 5 academic hospital-based centers in the United States and Canada; 82 patients from inpatient and outpatient settings were enrolled. Participants with recent VB transient ischemic attack or stroke and 50% or more atherosclerotic stenosis or occlusion in vertebral and/or basilar arteries underwent large-vessel flow measurement in the VB territory using QMRA. Physicians performing follow-up assessments were blinded to QMRA flow status. Follow-up included monthly telephone calls for 12 months and biannual clinical visits (for a minimum of 12 months, and up to 24 months or the final visit). Enrollment took place from July 1, 2008, to July 31, 2013, with study completion on June 30, 2014; data analysis was performed from October 1, 2014, to April 10, 2015. Standard medical management of stroke risk factors. The primary outcome was VB-territory stroke. Of the 82 enrolled patients, 72 remained eligible after central review of their angiograms. Sixty-nine of 72 patients completed the minimum 12-month follow-up; median follow-up was 23 (interquartile range, 14-25) months. Distal flow status was low in 18 of the 72 participants (25%) included in the analysis and was significantly associated with risk for a subsequent VB stroke (P = .04), with 12- and 24-month event-free survival rates of 78% and 70%, respectively, in the low-flow group vs 96% and 87%, respectively, in the normal-flow group. The hazard ratio, adjusted for age and stroke risk factors, in the low distal flow status group was 11.55 (95% CI, 1.88-71.00; P = .008). Medical risk factor management at 6-month intervals was similar between patients with low and normal distal flow. Distal flow status remained significantly associated with risk even when controlling for the degree of stenosis and location. Distal flow status determined using a noninvasive and practical imaging tool is robustly associated with risk for subsequent stroke in patients with symptomatic atherosclerotic VB occlusive disease. Identification of high-risk patients has important implications for future investigation of more aggressive interventional or medical therapies.

Occupational therapy practice in predriving assessment post stroke in the Irish context: findings from a nominal group technique meeting.

PubMed

Stapleton, Tadhg; Connelly, Deirdre

2010-01-01

Practice in the area of predriving assessment for people with stroke varies, and research findings are not always easily transferred into the clinical setting, particularly when such assessment is not conducted within a dedicated driver assessment programme. This article explores the clinical predriving assessment practices and recommendations of a group of Irish occupational therapists for people with stroke. A consensus meeting of occupational therapists was facilitated using a nominal group technique (NGT) to identify specific components of cognition, perception, and executive function that may influence fitness to return to driving and should be assessed prior to referral for on-road evaluation. Standardised assessments for use in predriving assessment were recommended. Thirteen occupational therapists speed of processing; perceptual components of spatial awareness, depth perception, and visual inattention; and executive components of planning, problem solving, judgment, and self-awareness. Consensus emerged for the use of the following standardised tests: Behavioural Assessment of Dysexecutive Syndrome (BADS), Test of Everyday Attention (TEA), Brain Injury Visual Assessment Battery for Adults (biVABA), Rivermead Perceptual Assessment Battery (RPAB), and Motor Free Visual Perceptual Test (MVPT). Tests were recommended that gave an indication of the patient's underlying component skills in the area of cognition, perception, and executive functions considered important for driving. Further research is needed in this area to develop clinical practice guidelines for occupational therapists for the assessment of fitness to return to driving after stroke.

Perlecan domain V is neuroprotective and proangiogenic following ischemic stroke in rodents

PubMed Central

Lee, Boyeon; Clarke, Douglas; Al Ahmad, Abraham; Kahle, Michael; Parham, Christi; Auckland, Lisa; Shaw, Courtney; Fidanboylu, Mehmet; Orr, Anthony Wayne; Ogunshola, Omolara; Fertala, Andrzej; Thomas, Sarah A.; Bix, Gregory J.

2011-01-01

Stroke is the leading cause of long-term disability and the third leading cause of death in the United States. While most research thus far has focused on acute stroke treatment and neuroprotection, the exploitation of endogenous brain self-repair mechanisms may also yield therapeutic strategies. Here, we describe a distinct type of stroke treatment, the naturally occurring extracellular matrix fragment of perlecan, domain V, which we found had neuroprotective properties and enhanced post-stroke angiogenesis, a key component of brain repair, in rodent models of stroke. In both rat and mouse models, Western blot analysis revealed elevated levels of perlecan domain V. When systemically administered 24 hours after stroke, domain V was well tolerated, reached infarct and peri-infarct brain vasculature, and restored stroke-affected motor function to baseline pre-stroke levels in these multiple stroke models in both mice and rats. Post-stroke domain V administration increased VEGF levels via a mechanism involving brain endothelial cell α5β1 integrin, and the subsequent neuroprotective and angiogenic actions of domain V were in turn mediated via VEGFR. These results suggest that perlecan domain V represents a promising approach for stroke treatment. PMID:21747167

Three-Dimensional Reconstruction of Cloud-to-Ground Lightning Using High-Speed Video and VHF Broadband Interferometer

NASA Astrophysics Data System (ADS)

Li, Yun; Qiu, Shi; Shi, Lihua; Huang, Zhengyu; Wang, Tao; Duan, Yantao

2017-12-01

The time resolved three-dimensional (3-D) spatial reconstruction of lightning channels using high-speed video (HSV) images and VHF broadband interferometer (BITF) data is first presented in this paper. Because VHF and optical radiations in step formation process occur with time separation no more than 1 μs, the observation data of BITF and HSV at two different sites provide the possibility of reconstructing the time resolved 3-D channel of lightning. With the proposed procedures for 3-D reconstruction of leader channels, dart leaders as well as stepped leaders with complex multiple branches can be well reconstructed. The differences between 2-D speeds and 3-D speeds of leader channels are analyzed by comparing the development of leader channels in 2-D and 3-D space. Since return stroke (RS) usually follows the path of previous leader channels, the 3-D speeds of the return strokes are first estimated by combination with the 3-D structure of the preceding leaders and HSV image sequences. For the fourth RS, the ratios of the 3-D to 2-D RS speeds increase with height, and the largest ratio of the 3-D to 2-D return stroke speeds can reach 2.03, which is larger than the result of triggered lightning reported by Idone. Since BITF can detect lightning radiation in a 360° view, correlated BITF and HSV observations increase the 3-D detection probability than dual-station HSV observations, which is helpful to obtain more events and deeper understanding of the lightning process.

Vagus nerve stimulation during rehabilitative training improves forelimb strength following ischemic stroke.

PubMed

Khodaparast, N; Hays, S A; Sloan, A M; Hulsey, D R; Ruiz, A; Pantoja, M; Rennaker, R L; Kilgard, M P

2013-12-01

Upper limb impairment is a common debilitating consequence of ischemic stroke. Physical rehabilitation after stroke enhances neuroplasticity and improves limb function, but does not typically restore normal movement. We have recently developed a novel method that uses vagus nerve stimulation (VNS) paired with forelimb movements to drive specific, long-lasting map plasticity in rat primary motor cortex. Here we report that VNS paired with rehabilitative training can enhance recovery of forelimb force generation following infarction of primary motor cortex in rats. Quantitative measures of forelimb function returned to pre-lesion levels when VNS was delivered during rehab training. Intensive rehab training without VNS failed to restore function back to pre-lesion levels. Animals that received VNS during rehab improved twice as much as rats that received the same rehabilitation without VNS. VNS delivered during physical rehabilitation represents a novel method that may provide long-lasting benefits towards stroke recovery. © 2013.

Tips for Daily Living

MedlinePlus

... Stories of Returning to School or Work Tough Work If You Can Get It Home Modifications Mental Health Tips for Maintaining a Positive Outlook and Well-Being Recreation Can Increase Awareness Improving Memory Submitting Your Story Stroke families put the ‘connection’ ...

Successful Intra-Arterial Thrombolysis for Acute Ischemic Stroke in the Immediate Postpartum Period: Case Report

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

Mendez, Jose C.; Masjuan, J.; Garcia, N.

2008-01-15

Stroke in pregnancy and the puerperium is a rare but potentially devastating event. We present the case of a previously healthy woman who underwent a cesarean delivery and experienced a middle cerebral artery thrombosis in the immediate postpartum period that was subsequently lysed with intra-arterial urokinase. The patient made a complete neurologic recovery. To the best of our knowledge, this is the first reported case of successful intra-arterial thrombolysis for ischemic stroke in the postpartum period.

The Nottingham Fatigue After Stroke (NotFAST) study: results from follow-up six months after stroke.

PubMed

Hawkins, Louise; Lincoln, Nadina B; Sprigg, Nikola; Ward, Nick S; Mistri, Amit; Tyrrell, Pippa; Worthington, Esme; Drummond, Avril

2017-12-01

Background Post-stroke fatigue is common and disabling. Objectives The aim of NotFAST was to examine factors associated with fatigue in stroke survivors without depression, six months after stroke. Methods Participants were recruited from four UK stroke units. Those with high levels of depressive symptoms (score ≥7 on Brief Assessment Schedule Depression Cards) or aphasia were excluded. Follow-up assessment was conducted at six months after stroke. They were assessed on the Fatigue Severity Scale, Rivermead Mobility Index, Nottingham Extended Activities of Daily Living scale, Barthel Index, Beck Anxiety Index, Brief Assessment Schedule Depression Cards, Impact of Event Scale-Revised, and Sleep Hygiene Index. Results Of the 371 participants recruited, 263 (71%) were contacted at six months after stroke and 213 (57%) returned questionnaires. Approximately half (n = 109, 51%) reported fatigue at six months. Of those reporting fatigue initially (n = 88), 61 (69%) continued to report fatigue. 'De novo' (new) fatigue was reported by 48 (38%) of those not fatigued initially. Lower Nottingham Extended Activities of Daily Living scores and higher Beck Anxiety Index scores were independently associated with fatigue at six months. Conclusions Half the stroke survivors reported fatigue at six months post-stroke. Reduced independence in activities of daily living and higher anxiety levels were associated with the level of fatigue. Persistent and delayed onset fatigue may affect independence and participation in rehabilitation, and these findings should be used to inform the development of appropriate interventions.

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.

Self-reported stroke symptoms without a prior diagnosis of stroke or transient ischemic attack: a powerful new risk factor for stroke.

PubMed

Kleindorfer, Dawn; Judd, Suzanne; Howard, Virginia J; McClure, Leslie; Safford, Monika M; Cushman, Mary; Rhodes, David; Howard, George

2011-11-01

Previously in the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort, we found 18% of the stroke/transient ischemic attack-free study population reported ≥1 stroke symptom at baseline. We sought to evaluate the additional impact of these stroke symptoms on risk for subsequent stroke. REGARDS recruited 30,239 US blacks and whites, aged 45+ years in 2003 to 2007 who are being followed every 6 months for events. All stroke events are physician-verified; those with prior diagnosed stroke or transient ischemic attack are excluded from this analysis. At baseline, participants were asked 6 questions regarding stroke symptoms. Measured stroke risk factors were components of the Framingham Stroke Risk Score. After excluding those with prior stroke or missing data, there were 24,412 participants in this analysis with a median follow-up of 4.4 years. Participants were 39% black, 55% female, and had median age of 64 years. There were 381 physician-verified stroke events. The Framingham Stroke Risk Score explained 72.0% of stroke risk; individual components explained between 0.2% (left ventricular hypertrophy) and 5.7% (age+race) of stroke risk. After adjustment for Framingham Stroke Risk Score factors, stroke symptoms were significantly related to stroke risk: for each stroke symptom reported, the risk of stroke increased by 21% per symptom. Among participants without self-reported stroke or transient ischemic attack, prior stroke symptoms are highly predictive of future stroke events. Compared with Framingham Stroke Risk Score factors, the impact of stroke symptom on the prediction of future stroke was almost as large as the impact of smoking and hypertension and larger than the impact of diabetes and heart disease.

Fuel system for rotary distributor fuel injection pump

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

Klopfer, K.H.; Kelly, W.W.

1993-06-01

In a fuel injection pump having a drive shaft, a pump rotor driven by the drive shaft, reciprocating pumping means with periodic intake and pumping strokes to periodically receive an intake charge of fuel and deliver fuel at high pressure for fuel injection is described; a distributor head with a plurality of angularly spaced distributor outlets, the pump rotor providing a distributor rotor with a distributor port connected to the pumping means, the distributor rotor being rotatably mounted in the distributor head for sequential registration of the distributor port with the distributor outlets for distributing said high pressure delivery ofmore » fuel thereto; a fuel system for supplying fuel to the pumping means, having an end chamber at one end of the pump rotor and a fuel supply pump driven by the drive shaft and having an inlet and outlet, the supply pump outlet being connected to the end chamber for supplying fuel thereto, and a pressure regulator for regulating the fuel pressure in the end chamber; and a control valve connected between the pumping means and the end chamber and selectively opened during the intake strokes to supply fuel to the pumping means from the end chamber and during the pumping strokes to spill fuel from the pumping means into the end chamber to terminate said high pressure delivery of fuel; the improvement wherein the fuel system comprises a fuel return passage connected in series with the end chamber downstream thereof, wherein the pressure regulator is mounted in the return passage for regulating the upstream fuel pressure, including the upstream fuel pressure within the end chamber, and is connected for conducting excess fuel for return to the supply pump inlet, and wherein the supply pump is driven by the drive shaft to supply fuel at a rate exceeding the rate of said high pressure delivery of fuel for fuel injection and to provide excess fuel flow continuously through the end chamber and return passage to the pressure regulator.« less

Artistic Skills Recovery and Compensation in Visual Artists after Stroke.

PubMed

Petcu, Eugen Bogdan; Sherwood, Katherine; Popa-Wagner, Aurel; Buga, Ana Maria; Aceti, Lanfranco; Miroiu, Rodica Ileana

2016-01-01

Art is a characteristic of mankind, which requires superior central nervous processing and integration of motor functions with visual information. At the present time, a significant amount of information related to neurobiological basis of artistic creation has been derived from neuro-radiological cognitive studies, which have revealed that subsequent to tissue destruction, the artists continue to create art. The current study aims to review the most important cases of visual artists with stroke and to discuss artistic skills recovery and compensation as well as artistic style after stroke. The role of various central nervous system regions in artistic creation was reviewed on the basis of previously published functional studies. Our PubMed search (1995-2015) has identified 10 famous artists with right cerebral stroke as well as 5 with left cerebral stroke who survived and continued to create art after stroke. As the artists included in this review lived at various times during the twentieth century and in different countries, clinical information related to their case was limited. However, it appears that artistic skills recovery and compensation appear within days after stroke. Some of the artists would subsequently change their artistic style. All these elements have been evaluated within the context of specific clinical cases. The poststroke artistic skills recovery and compensation with development of a new style or the opposite, regaining the previous prestroke style, represents a significant element of clinical importance in medical rehabilitation as well as neuroesthetics, which requires further evaluation. At the present time, the molecular mechanisms of artistic creation are poorly understood, and more standardized clinical and experimental studies are needed.

Transthyretin Concentrations in Acute Stroke Patients Predict Convalescent Rehabilitation.

PubMed

Isono, Naofumi; Imamura, Yuki; Ohmura, Keiko; Ueda, Norihide; Kawabata, Shinji; Furuse, Motomasa; Kuroiwa, Toshihiko

2017-06-01

For stroke patients, intensive nutritional management is an important and effective component of inpatient rehabilitation. Accordingly, acute care hospitals must detect and prevent malnutrition at an early stage. Blood transthyretin levels are widely used as a nutritional monitoring index in critically ill patients. Here, we had analyzed the relationship between the transthyretin levels during the acute phase and Functional Independence Measure in stroke patients undergoing convalescent rehabilitation. We investigated 117 patients who were admitted to our hospital with acute ischemic or hemorrhagic stroke from February 2013 to October 2015 and subsequently transferred to convalescent hospitals after receiving acute treatment. Transthyretin concentrations were evaluated at 3 time points as follows: at admission, and 5 and 10 days after admission. After categorizing patients into 3 groups according to the minimum transthyretin level, we analyzed the association between transthyretin and Functional Independence Measure. In our patients, transthyretin levels decreased during the first 5 days after admission and recovered slightly during the subsequent 5 days. Notably, Functional Independence Measure efficiency was significantly associated with the decrease in transthyretin levels during the 5 days after admission. Patients with lower transthyretin levels had poorer Functional Independence Measure outcomes and tended not to be discharged to their own homes. A minimal transthyretin concentration (<10 mg/dL) is predictive of a poor outcome in stroke patients undergoing convalescent rehabilitation. In particular, an early decrease in transthyretin levels suggests restricted rehabilitation efficiency. Accordingly, transthyretin levels should be monitored in acute stroke patients to indicate mid-term rehabilitation prospects. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Velocity-image model for online signature verification.

PubMed

Khan, Mohammad A U; Niazi, Muhammad Khalid Khan; Khan, Muhammad Aurangzeb

2006-11-01

In general, online signature capturing devices provide outputs in the form of shape and velocity signals. In the past, strokes have been extracted while tracking velocity signal minimas. However, the resulting strokes are larger and complicated in shape and thus make the subsequent job of generating a discriminative template difficult. We propose a new stroke-based algorithm that splits velocity signal into various bands. Based on these bands, strokes are extracted which are smaller and more simpler in nature. Training of our proposed system revealed that low- and high-velocity bands of the signal are unstable, whereas the medium-velocity band can be used for discrimination purposes. Euclidean distances of strokes extracted on the basis of medium velocity band are used for verification purpose. The experiments conducted show improvement in discriminative capability of the proposed stroke-based system.

Atrial Fibrillation Ablation and its Impact on Stroke.

PubMed

Graves, Kevin G; Jacobs, Victoria; May, Heidi T; Cutler, Michael J; Day, John D; Bunch, T Jared

2018-01-24

Atrial fibrillation (AF) is a commonly encountered arrhythmia, which is not yet fully understood. Catheter ablation has shown to be an effective strategy for rhythm management and several small or retrospective studies have shown that stroke rates are decreased in ablated AF patients compared to those medically managed. Several studies even show that ablation returns stroke risk to that of non-AF patients. Large scale, prospective trials will further illuminate this connection and provide mechanistic understanding of the role of the procedure versus the process of selection for the procedure and peri- and post-procedural therapy and management. Furthermore, modification of risk factors associated with AF show a significant increase in the sustained success of AF ablation and can also moderate the progression of AF.

Functional and motor outcome 5 years after stroke is equivalent to outcome at 2 months: follow-up of the collaborative evaluation of rehabilitation in stroke across Europe.

PubMed

Meyer, Sarah; Verheyden, Geert; Brinkmann, Nadine; Dejaeger, Eddy; De Weerdt, Willy; Feys, Hilde; Gantenbein, Andreas R; Jenni, Walter; Laenen, Annouschka; Lincoln, Nadina; Putman, Koen; Schuback, Birgit; Schupp, Wilfried; Thijs, Vincent; De Wit, Liesbet

2015-06-01

Recovery of patients within the first 6 months after stroke is well documented, but there has been little research on long-term recovery. The aim of this study was to analyze functional and motor recovery between admission to rehabilitation centres and 5 years after stroke. This follow-up of the Collaborative Evaluation of Rehabilitation in Stroke Across Europe study, included patients from 4 European rehabilitation centres. Patients were assessed on admission, at 2 and 6 months, and 5 years after stroke, using the Barthel Index, Rivermead Motor Assessment Gross Function, Leg and Trunk function, and Arm function. Linear mixed models were used, corrected for baseline characteristics. To account for the drop-out during follow-up, the analysis is likelihood-based (assumption of missingness at random). A total of 532 patients were included in this study, of which 238 were followed up at 5 years post stroke. Mean age at stroke onset was 69 (±10 SD) years, 53% were men, 84% had ischemic strokes, and 53% had left-sided motor impairment. Linear mixed model analysis revealed a significant deterioration for all 4 outcomes between 6 months and 5 years (P<0.0001). Scores at 2 months were not statistically significant different from scores at 5 years after stroke. Higher age (P<0.0001) and increasing stroke severity on admission (P<0.0001) negatively affected long-term functional and motor recovery. Five-year follow-up revealed deterioration in functional and motor outcome, with a return to the level measured at 2 months. Increasing age and increasing stroke severity negatively affected recovery up to 5 years after stroke. © 2015 American Heart Association, Inc.

New evidence for therapies in stroke rehabilitation.

PubMed

Dobkin, Bruce H; Dorsch, Andrew

2013-06-01

Neurologic rehabilitation aims to reduce impairments and disabilities so that persons with serious stroke can return to participation in usual self-care and daily activities as independently as feasible. New strategies to enhance recovery draw from a growing understanding of how types of training, progressive task-related practice of skills, exercise for strengthening and fitness, neurostimulation, and drug and biological manipulations can induce adaptations at multiple levels of the nervous system. Recent clinical trials provide evidence for a range of new interventions to manage walking, reach and grasp, aphasia, visual field loss, and hemi-inattention.

Transient ischameic attack/stroke electronic decision support: a 14-month safety audit.

PubMed

Lavin, Timothy L; Ranta, Annemarei

2014-02-01

To assess the safety of a Transient Ischameic Attack (TIA)/Stroke Electronic Decision Support (EDS) tool in the primary care setting intended to aid general practitioners in the timely management of transient ischemic attacks (TIAs). A 14-month safety audit reviewing all patients managed with the help of the TIA/Stroke EDS tool. Major morbidity and mortality were assessed by screening patients for subsequent hospital admissions and investigating potential links to EDS use. Seventy-nine patients were managed with the aid of the TIA/Stroke EDS. EDS use resulted in 8 appropriate immediate hospital admissions because of patients being at high risk of stroke. Three patients had delayed admission, but care was fully guideline based and patients had no adverse outcome. Eleven admissions were unrelated to EDS use. Two deaths occurred; these did not result from inappropriate EDS advice. Results suggest that TIA/Stroke EDS use is not associated with major morbidity or mortality. Larger studies are needed to draw more definite conclusions regarding the utility of this TIA/Stroke EDS in preventing strokes. Copyright © 2014 National Stroke Association. All rights reserved.

Adverse reactions and other factors that impact subsequent blood donation visits.

PubMed

Custer, Brian; Rios, Jorge A; Schlumpf, Karen; Kakaiya, Ram M; Gottschall, Jerome L; Wright, David J

2012-01-01

The importance of adverse reactions in terms of donor safety recently has received significant attention, but their role in subsequent donation behavior has not been thoroughly investigated. Six REDS-II blood centers provided data for this analysis. Summary minor and major adverse reaction categories were created. The influence of adverse reactions on donation was examined in two ways: Kaplan-Meier curves were generated to determine the cumulative pattern of first return, and adjusted odds ratios (AORs) for demographic and other factors positively and negatively associated with return were estimated using multivariable logistic regression. Donors who had major reactions had longer times to return than donors with minor or no reactions. The AOR of returning for donors with major reactions was 0.32 (95% confidence interval [CI], 0.28-0.37) and with minor reactions 0.59 (95% CI, 0.56-0.62) when compared to donors who did not have reactions. Conversely, the most important factors positively associated with return were the number of donations in the previous year and increasing age. Subsequent return, whether a major, minor, or no reaction occurred, varied by blood center. Factors that are associated with the risk of having adverse reactions were not substantial influences on the return after adverse reactions. Having an adverse reaction leads to significantly lower odds of subsequent donation irrespective of previous donation history. Factors that have been associated with a greater risk of adverse reactions were not important positive or negative predictors of return after a reaction. © 2011 American Association of Blood Banks.

Comparison of cardiovascular risk factors and survival in patients with ischemic or hemorrhagic stroke.

PubMed

Henriksson, Karin M; Farahmand, Bahman; Åsberg, Signild; Edvardsson, Nils; Terént, Andreas

2012-06-01

Differences in risk factor profiles between patients with ischemic and hemorrhagic stroke may have an impact on subsequent mortality. To explore cardiovascular disease risk factors, including the CHADS(2) score, with survival after ischemic or hemorrhagic stroke. Between 2001 and 2005, 87 111 (83%) ischemic stroke, 12 497 (12%) hemorrhagic stroke, and 5435 (5%) patients with unspecified stroke were identified in the Swedish Stroke Register. Data on gender, age, and cardiovascular disease risk factors were linked to the Swedish Hospital Discharge and Cause of Death Registers. Adjusted odds and hazard ratios and 95% confidence interval were calculated using logistic and Cox proportional hazard regression models. Hemorrhagic stroke patients were younger than ischemic stroke patients. All cardiovascular disease risk factors studied, alone or combined in the CHADS(2) score, were associated with higher odds ratios for ischemic stroke vs. hemorrhagic stroke. Higher CHADS(2) scores and all studied risk factors except hypertension were associated with higher odds ratio for death by ischemic stroke than hemorrhagic stroke. Ischemic stroke was associated with lower early mortality (within 30 days) vs. hemorrhagic stroke (hazard ratio = 0·28, confidence interval 0·27 to 0·29). Patients with hemorrhagic stroke had a higher risk of dying within the first 30 days after stroke, but the risk of death was similar in the two groups after one-month. Hypertension was the only cardiovascular disease risk factor associated with an increased mortality rate for hemorrhagic stroke as compared to ischemic stroke. © 2011 The Authors. International Journal of Stroke © 2011 World Stroke Organization.

From clinical to tissue-based dual TIA: Validation and refinement of ABCD3-I score.

PubMed

Dai, Qiliang; Sun, Wen; Xiong, Yunyun; Hankey, Graeme J; Xiao, Lulu; Zhu, Wusheng; Ma, Minmin; Liu, Wenhua; Liu, Dezhi; Cai, Qiankun; Han, Yunfei; Duan, Lihui; Chen, Xiangliang; Xu, Gelin; Liu, Xinfeng

2015-04-07

To investigate whether dual tissue-defined ischemic attacks, defined as multiple diffusion-weighted imaging lesions of different age and/or arterial territory (dual DWI), are an independent and stronger predictor of 90-day stroke than dual clinical TIAs (dual TIA). Consecutive patients with clinically defined TIA were enrolled and assessed clinically and by MRI within 3 days. The predictive ability of the ABCD clinical factors, dual TIA, and dual DWI was evaluated by means of multivariate logistic regression. Among 658 patients who were included in the study and completed 90 days of follow-up, a total of 70 patients (10.6%) experienced subsequent stroke by 90 days. Multivariate logistic regression indicated that dual DWI was an independent predictor for subsequent stroke (odds ratio 4.64, 95% confidence interval 2.15-10.01), while dual TIA was not (odds ratio 1.18, 95% confidence interval 0.69-2.01). C statistics was higher when the item of dual TIA in ABCD3-I score was replaced by dual DWI (0.759 vs 0.729, p = 0.035). The net reclassification value for 90-day stroke risk was also improved (continuous net reclassification improvement 0.301, p = 0.017). Dual DWI independently predicted future stroke in patients with TIA. A new ABCD3-I score with dual DWI instead of dual clinical TIA may improve risk stratification for early stroke risk after TIA. © 2015 American Academy of Neurology.

Facilitating the Involvement of People with Aphasia in Stroke Research by Developing Communicatively Accessible Research Resources

ERIC Educational Resources Information Center

Pearl, Gill; Cruice, Madeline

2017-01-01

People with aphasia can be marginalized by a communicatively inaccessible society. Compounding this problem, routinized exclusion from stroke research leads to bias in the evidence base and subsequent inequalities in service provision. Within the United Kingdom, the Clinical Research Network of the National Institute of Health identified this…

Effects of stroke education using an animated cartoon and a manga on elementary school children.

PubMed

Sakamoto, Yuki; Yokota, Chiaki; Miyashita, Fumio; Amano, Tatsuo; Shigehatake, Yuya; Oyama, Satoshi; Itagaki, Naruhiko; Okumura, Kosuke; Toyoda, Kazunori; Minematsu, Kazuo

2014-08-01

Stroke education for the youth is expected to reduce prehospital delay by informing the bystander of appropriate action to take and providing knowledge to prevent onset of stroke in future. Previously, we developed effective teaching materials consisting of an animated cartoon and a Manga for junior high school students. The aim of this study was to evaluate the feasibility and effectiveness of our educational materials for stroke education taught by schoolteachers to elementary school children. Using our teaching materials, a 30-minute lesson was given by trained general schoolteachers. Questionnaires on stroke knowledge (symptoms and risk factors) and action to take on identification of suspected stroke symptoms were filled out by school children before, immediately after, and at 3 months after completion of the lesson. A total of 219 children (aged 10 or 11 years) received the stroke lesson. Stroke knowledge significantly increased immediately after the lesson compared with before (symptoms, P < .001; risk factors, P < .001); however, correct answer rates decreased at 3 months immediately after completion of the lesson (symptoms, P = .002; risk factors, P = .045). The proportion of the number of children calling emergency medical service on identifying stroke symptoms was higher immediately after the lesson than baseline (P = .007) but returned to the baseline at 3 months after the lesson. Stroke lesson by schoolteachers using our teaching materials consisting of an animated cartoon and a Manga that was previously used for junior high school students was feasible for elementary school children. However, revision of the materials is required for better retention of stroke knowledge for children. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Effects of short term water immersion on peripheral reflex excitability in hemiplegic and healthy individuals: A preliminary study

PubMed Central

Cronin, N.J.; Valtonen, A.M.; Waller, B.; Pöyhönen, T.; Avela, J.

2016-01-01

Background: Reflex excitability is increased in hemiplegic patients compared to healthy controls. One challenge of stroke rehabilitation is to decrease the effects of hyperreflexia, which may be possible with water immersion. Methods/Aims: The present study examined the effects of acute water immersion on electrically-evoked Hmax:Mmax ratios (a measure of reflex excitability) in 7 hyperreflexive hemiplegic patients and 7 age-matched healthy people. Hmax:Mmax ratios were measured from soleus on dry land (L1), immediately after (W1) and 5 minutes after immersion (W5), and again after five minutes on land (L5). Results: Water immersion led to an acute increase in Hmax:Mmax ratio in both groups. However, after returning to dry land, there was a non-significant decrease in the Hmax:Mmax ratio of 8% in the hemiplegic group and 10% in healthy controls compared to pre-immersion values. Interpretation: A short period of water immersion can decrease peripheral reflex excitability after returning to dry land in both healthy controls and post-stroke patients, although longer immersion periods may be required for sustainable effects. Water immersion may offer promise as a low-risk, non-invasive and non-pharmaceutical method of decreasing hyperreflexivity, and could thus support aquatic rehabilitation following stroke. PMID:26944824

Effects of short term water immersion on peripheral reflex excitability in hemiplegic and healthy individuals: A preliminary study.

PubMed

Cronin, N J; Valtonen, A M; Waller, B; Pöyhönen, T; Avela, J

2016-03-01

Reflex excitability is increased in hemiplegic patients compared to healthy controls. One challenge of stroke rehabilitation is to decrease the effects of hyperreflexia, which may be possible with water immersion. Methods/Aims: The present study examined the effects of acute water immersion on electrically-evoked Hmax:Mmax ratios (a measure of reflex excitability) in 7 hyperreflexive hemiplegic patients and 7 age-matched healthy people. Hmax:Mmax ratios were measured from soleus on dry land (L1), immediately after (W1) and 5 minutes after immersion (W5), and again after five minutes on land (L5). Water immersion led to an acute increase in Hmax:Mmax ratio in both groups. However, after returning to dry land, there was a non-significant decrease in the Hmax:Mmax ratio of 8% in the hemiplegic group and 10% in healthy controls compared to pre-immersion values. A short period of water immersion can decrease peripheral reflex excitability after returning to dry land in both healthy controls and post-stroke patients, although longer immersion periods may be required for sustainable effects. Water immersion may offer promise as a low-risk, non-invasive and non-pharmaceutical method of decreasing hyperreflexivity, and could thus support aquatic rehabilitation following stroke.

Mechanisms of decreased left ventricular preload during continuous positive pressure ventilation in ARDS

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

Dhainaut, J.F.; Devaux, J.Y.; Monsallier, J.F.

1986-07-01

Continuous positive pressure ventilation is associated with a reduction in left ventricular preload and cardiac output, but the mechanisms responsible are controversial. The decrease in left ventricular preload may result exclusively from a decreased systemic venous return due to increased pleural pressure, or from an additional effect such as decreased left ventricular compliance. To determine the mechanisms responsible, we studied the changes in cardiac output induced by continuous positive pressure ventilation in eight patients with the adult respiratory distress syndrome. We measured cardiac output by thermodilution, and biventricular ejection fraction by equilibrium gated blood pool scintigraphy. Biventricular end-diastolic volumes weremore » then calculated by dividing stroke volume by ejection fraction. As positive end-expiratory pressure increased from 0 to 20 cm H/sub 2/O, stroke volume and biventricular end-diastolic volumes fell about 25 percent, and biventricular ejection fraction remained unchanged. At 20 cm H/sub 2/O positive end-expiratory pressure, volume expansion for normalizing cardiac output restored biventricular end-diastolic volumes without markedly changing biventricular end-diastolic transmural pressures. The primary cause of the reduction in left ventricular preload with continuous positive pressure ventilation appears to be a fall in venous return and hence in right ventricular stroke volume, without evidence of change in left ventricular diastolic compliance.« less

An Exertional Heat Stroke Survivor's Return to Running: An Integrated Approach on the Treatment, Recovery, and Return to Activity.

PubMed

Adams, William M; Hosokawa, Yuri; Huggins, Robert A; Mazerolle, Stephanie M; Casa, Douglas J

2016-08-01

Evidence-based best practices for the recognition and treatment of exertional heat stroke (EHS) indicate that rectal thermometry and immediate, aggressive cooling via cold-water immersion ensure survival from this medical condition. However, little is known about the recovery, medical follow-up, and return to activity after an athlete has suffered EHS. To highlight the transfer of evidenced-based research into clinical practice by chronicling the treatment, recovery, and return to activity of a runner who suffered an EHS during a warm-weather road race. Case study. Warm-weather road race. 53-y-old recreationally active man. A runner's treatment, recovery, and return to activity from EHS and 2014 Falmouth Road Race performance. Runner's perceptions and experiences with EHS, body temperature, heart rate, hydration status, exercise intensity. The runner successfully completed the 2014 Falmouth Road Race without incident of EHS. Four dominant themes emerged from the data: predisposing factors, ideal treatment, lack of medical follow-up, and patient education. The first theme identified 3 predisposing factors that contributed to the runner's EHS: hydration, sleep loss, and lack of heat acclimatization. The runner received ideal treatment using evidence-based best practices. A lack of long-term medical care following the EHS with no guidance on the runner's return to full activity was observed. The runner knew very little about EHS before the 2013 race, which drove him to seek knowledge as to why he suffered EHS. Using this newly learned information, he successfully completed the 2014 Falmouth Road Race without incident. This case supports prior literature examining the factors that predispose individuals to EHS. Although evidence-based best practices regarding prompt recognition and treatment of EHS ensure survival, this case highlights the lack of medical follow-up and physician-guided return to activity after EHS.

Post-stroke infection: a role for IL-1ra?

PubMed

Tanzi, Pat; Cain, Kevin; Kalil, Angela; Zierath, Dannielle; Savos, Anna; Gee, J Michael; Shibata, Dean; Hadwin, Jessica; Carter, Kelly; Becker, Kyra

2011-04-01

Infection is common following stroke and is independently associated with worse outcome. Clinical studies suggest that infections occur more frequently in those individuals with stroke-induced immunologic dysfunction. This study sought to explore the contribution of immunomodulatory cytokines and hormones to lymphocyte function and infection risk. Patients (N = 112) were enrolled as soon as possible after the onset of ischemic stroke. Blood was drawn to assess plasma cortisol, IL-10, IL-1ra, lymphocyte numbers, and lymphocyte function at 72 h after stroke onset; infections were censored through 21 days after stroke onset. Infection occurred in 25% of patients. Stroke severity was the most important predictor of infection risk. Increased plasma cortisol, IL-10, and IL-1ra, as well as decreased lymphocyte numbers, at 72 h after stroke onset were associated with risk of subsequent infection. After controlling for stroke severity, only IL-1ra was independently associated with infection risk, and the degree of risk was consistent throughout the post-stroke period. Infection, but not IL-1ra itself, was associated with worse outcome at 3 months. In this study cohort, increased plasma IL-1ra was independently associated with the risk of post-stroke infection. Further studies are needed to validate this finding, which could have important implications for stroke therapy.

'Getting back to real living': A qualitative study of the process of community reintegration after stroke.

PubMed

Wood, Jennifer P; Connelly, Denise M; Maly, Monica R

2010-11-01

To examine the process of community reintegration over the first year following stroke, from the patient's perspective. Qualitative, longitudinal, grounded theory study involving ten participants. During the first year post discharge from inpatient rehabilitation, 46 one-on-one semi-structured interviews were conducted with ten participants. Interviews were completed with participants before discharge from inpatient stroke rehabilitation and in their homes at two weeks, three months, six months and one year post discharge. Analysis was guided by grounded theory methods described by Corbin and Strauss. Four women and six men (mean age 59.6 ± 18.0, all with left hemiparesis and without aphasia) who had sustained their first hemispheric stroke and were returning to the community following inpatient rehabilitation. The process of community reintegration after stroke involved transitioning through a series of goals: gaining physical function, establishing independence, adjusting expectations and getting back to real living. The ultimate challenge for stroke survivors during this process of community reintegration was to create a balance between their expectations of themselves and their physical capacity to engage in meaningful roles. Over the first year after stroke, participants reported that the process of community reintegration was marked by ongoing changes in their goals. Formal and informal caregivers need to work with stroke survivors living in the community to facilitate realistic and achievable goal setting. Tools which identify meaningful activities should also be incorporated to provide stroke survivors with the opportunity to contribute and engage with others in the community.

Prediction of motor recovery after stroke: advances in biomarkers.

PubMed

Stinear, Cathy M

2017-10-01

Stroke remains a leading cause of adult disability, and the recovery of motor function after stroke is crucial for the patient to regain independence. However, making accurate predictions of a patient's motor recovery and outcome is difficult when based on clinical assessment alone. Clinical assessment of motor impairment within a few days of stroke can help to predict subsequent recovery, while neurophysiological and neuroimaging biomarkers of corticomotor structure and function can help to predict both motor recovery and motor outcome after stroke. The combination of biomarkers can provide clinically useful information when planning the personalised rehabilitation of a patient. These biomarkers can also be used for patient selection and stratification in trials investigating rehabilitation interventions that are initiated early after stroke. Ongoing multicentre trials that incorporate motor biomarkers could help to bring their use into routine clinical practice. Copyright © 2017 Elsevier Ltd. All rights reserved.

Establishing research priorities relating to the long-term impact of TIA and minor stroke through stakeholder-centred consensus.

PubMed

Turner, Grace M; Backman, Ruth; McMullan, Christel; Mathers, Jonathan; Marshall, Tom; Calvert, Melanie

2018-01-01

What is the problem and why is this important? Mini-strokes are similar to full strokes, but symptoms last less than 24 h. Many people (up to 70%) have long-term problems after a mini-stroke, such as anxiety; depression; problems with brain functioning (like memory loss); and fatigue (feeling tired). However, the current healthcare pathway only focuses on preventing another stroke and care for other long-term problems is not routinely given. Without proper treatment, people with long-term problems after a mini-stroke could have worse quality of life and may find it difficult to return to work and their social activities. What is the aim of the research? We wanted to understand the research priorities of patients, health care professionals and key stakeholders relating to the long-term impact of mini-stroke. How did we address the problem? We invited patients, clinicians, researchers and other stakeholders to attend a meeting. At the meeting people discussed the issues relating to the long-term impact of mini-stroke and came to an agreement on their research priorities. There were three stages: (1) people wrote down their individual research suggestions; (2) in smaller groups people came to an agreement on what their top research questions were; and (3) the whole group agreed final research priorities. What did we find? Eleven people attended who were representatives for patients, GPs, stroke consultants, stroke nurses, psychologists, the Stroke Association (charity) and stroke researchers, The group agreed on eleven research questions which they felt were the most important to improve health and well-being for people who have had a mini-stroke.The eleven research questions encompass a range of categories, including: understanding the existing care patients receive (according to diagnosis and geographical location); exploring what optimal care post-TIA/minor stroke should comprise (identifying and treating impairments, information giving and support groups) and how that care should be delivered (clinical setting and follow-up pathway); impact on family members; and education/training for health care professionals. Background Clinical management after transient ischaemic attack (TIA) and minor stroke focuses on stroke prevention. However, evidence demonstrates that many patients experience ongoing residual impairments. Residual impairments post-TIA and minor stroke may affect patients' quality of life and return to work or social activities. Research priorities of patients, health care professionals and key stakeholders relating to the long-term impact of TIA and minor stroke are unknown. Methods Our objective was to establish the top shared research priorities relating to the long-term impact of TIA and minor stroke through stakeholder-centred consensus. A one-day priority setting consensus meeting took place with representatives from different stakeholder groups in October 2016 (Birmingham, UK). Nominal group technique was used to establish research priorities. This involved three stages: (i) gathering research priorities from individual stakeholders; (ii) interim prioritisation in three subgroups; and (iii) final priority setting. Results The priority setting consensus meeting was attended by 11 stakeholders. The individual stakeholders identified 34 different research priorities. During the interim prioritisation exercise, the three subgroups generated 24 unique research priorities which were discussed as a whole group. Following the final consensus discussion, 11 shared research priorities were unanimously agreed.The 11 research questions encompass a range of categories, including: understanding the existing care patients receive (according to diagnosis and geographical location); exploring what optimal care post-TIA/minor stroke should comprise (identifying and treating impairments, information giving and support groups) and how that care should be delivered (clinical setting and follow-up pathway); impact on family members; and education/training for health care professionals. Conclusions Eleven different research priorities were established through stakeholder-centred consensus. These research questions could usefully inform the research agenda and policy decisions for TIA and minor stroke. Inclusion of stakeholders in setting research priorities is important to increase the relevance of research and reduce research waste.

The Role of Heat Tolerance Testing in Recovery and Return to Duty

DTIC Science & Technology

2008-10-01

CV diseases Hyperthyroidism Pheochromocytoma Infectious diseases Diabetes mellitus Psychiatric illness Parkinsonism Congenital abnormalities: CF...environments. To assess the heat tolerance status of prior heat stroke patient. Heat tolerance test (HTT) “HTT was effective in evaluating the heat tolerance

Vertebral Artery Dissection Causing Stroke After Trampoline Use.

PubMed

Casserly, Courtney S; Lim, Rodrick K; Prasad, Asuri Narayan

2015-11-01

The aim of this study was to report a case of a 4-year-old boy who had been playing on the trampoline and presented to the emergency department (ED) with vomiting and ataxia, and had a vertebral artery dissection with subsequent posterior circulation infarcts. This study is a chart review. The patient presented to the emergency department with a 4-day history of vomiting and gait unsteadiness. A computed tomography scan of his head revealed multiple left cerebellar infarcts. Subsequent magnetic resonance imaging/magnetic resonance angiogram of his head and neck demonstrated multiple infarcts involving the left cerebellum, bilateral thalami, and left occipital lobe. A computed tomography angiogram confirmed the presence of a left vertebral artery dissection. Vertebral artery dissection is a relatively common cause of stroke in the pediatric age group. Trampoline use has been associated with significant risk of injury to the head and neck. Patients who are small and/or young are most at risk. In this case, minor trauma secondary to trampoline use could be a possible mechanism for vertebral artery dissection and subsequent strokes. The association in this case warrants careful consideration because trampoline use could pose a significant risk to pediatric users.

Age accounts for racial differences in ischemic stroke volume in a population-based study.

PubMed

Zakaria, Tarek; Lindsell, Christopher J; Kleindorfer, Dawn; Alwell, Kathleen; Moomaw, Charles J; Woo, Daniel; Szaflarski, Jerzy P; Khoury, Jane; Miller, Rosie; Broderick, Joseph P; Kissela, Brett

2008-01-01

The stroke volume among black ischemic stroke patients in phase I of the population-based Greater Cincinnati/Northern Kentucky Stroke Study (GCNKSS) was smaller than reported among acute stroke studies, with a median stroke volume of 2.5 cm. However, it is not known if stroke volume was similar between black and white patients within the same study population. Phase II of the GCNKSS identified all ischemic strokes between July 1993 and June 1994. The stroke volume was estimated by study physicians using the modified ellipsoid method. Analysis of stroke volume by race, sex and age was performed for strokes with a measurable lesion of >or=0.5 cm(3). Among verified cases of ischemic stroke, 334 patients were eligible for this analysis. There were 191 whites (57%) and 143 blacks (43%). The mean age was 69.4 years. The median stroke volume for all patients was 8.8 cm(3) (range 0.5-540), with a mean of 36.4 cm(3). Stroke volume was not different between men and women, and it tended to increase with age. Although stroke volume was significantly higher among whites, age was a confounding factor. Subsequent analysis of stroke volume stratified by age showed no difference between blacks and whites in any age group. Our data show that most ischemic stroke lesions, regardless of the race, are of small size, and this may be an important reason for the low percentage of strokes treated currently with tissue-type plasminogen activator. The association of age with stroke volume requires further study. Copyright 2008 S. Karger AG, Basel.

Role of prediabetes in stroke

PubMed Central

Mijajlović, Milija D; Aleksić, Vuk M; Šternić, Nadežda M; Mirković, Mihailo M; Bornstein, Natan M

2017-01-01

Stroke is one of the leading causes of death and probably the greatest cause of adult disability worldwide. Diabetes mellitus (DM) is a state of accelerated aging of blood vessels. Patients with diabetes have increased risk of stroke. Hyperglycemia represents a risk factor for poor outcome following stroke, and probably is just a marker of poor outcome rather than a cause. Lowering of blood glucose levels has not been shown to improve prognosis. Also, prevention of stroke risk among patients with DM is not improved with therapy for reduction of glucose levels. On the other hand, prediabetes, a metabolic state between normal glucose metabolism and diabetes, is a risk factor for the development of DM type 2 and subsequently for stroke. Several methods are known to identify prediabetes patients, including fasting plasma glucose levels, 2-hour post load glucose levels, and glycosylated hemoglobin levels. In this text, we tried to summarize known data about diagnosis, epidemiology, risk factors, pathophysiology, and prevention of prediabetes in relation to DM and stroke. PMID:28203079

Validation of the Neurological Fatigue Index for stroke (NFI-Stroke)

PubMed Central

2012-01-01

Background Fatigue is a common symptom in Stroke. Several self-report scales are available to measure this debilitating symptom but concern has been expressed about their construct validity. Objective To examine the reliability and validity of a recently developed scale for multiple sclerosis (MS) fatigue, the Neurological Fatigue Index (NFI-MS), in a sample of stroke patients. Method Six patients with stroke participated in qualitative interviews which were analysed and the themes compared for equivalence to those derived from existing data on MS fatigue. 999 questionnaire packs were sent to those with a stroke within the past four years. Data from the four subscales, and the Summary scale of the NFI-MS were fitted to the Rasch measurement model. Results Themes identified by stroke patients were consistent with those identified by those with MS. 282 questionnaires were returned and respondents had a mean age of 67.3 years; 62% were male, and were on average 17.2 (SD 11.4, range 2–50) months post stroke. The Physical, Cognitive and Summary scales all showed good fit to the model, were unidimensional, and free of differential item functioning by age, sex and time. The sleep scales failed to show adequate fit in their current format. Conclusion Post stroke fatigue appears to be represented by a combination of physical and cognitive components, confirmed by both qualitative and quantitative processes. The NFI-Stroke, comprising a Physical and Cognitive subscale, and a 10-item Summary scale, meets the strictest measurement requirements. Fit to the Rasch model allows conversion of ordinal raw scores to a linear metric. PMID:22587411

tPA variant tPA-A296-299 Prevents impairment of cerebral autoregulation and necrosis of hippocampal neurons after stroke by inhibiting upregulation of ET-1.

PubMed

Armstead, William M; Hekierski, Hugh; Yarovoi, Serge; Higazi, Abd Al-Roof; Cines, Douglas B

2018-01-01

Tissue-type plasminogen activator (tPA) is neurotoxic and exacerbates uncoupling of cerebral blood flow (CBF) and metabolism after stroke, yet it remains the sole FDA-approved drug for treatment of ischemic stroke. Upregulation of c-Jun-terminal kinase (JNK) after stroke contributes to tPA-mediated impairment of autoregulation, but the role of endothelin-1 (ET-1) is unknown. Based on the Glasgow Coma Scale, impaired autoregulation is linked to adverse outcomes after TBI, but correlation with hippocampal histopathology after stroke has not been established. We propose that given after stroke, tPA activates N-Methyl-D-Aspartate receptors (NMDA-Rs) and upregulates ET-1 in a JNK dependent manner, imparing autoregulation and leading to histopathology. After stroke, CBF was reduced in the hippocampus and reduced further during hypotension, which did not occur in hypotensive sham pigs, indicating impairment of autoregulation. Autoregulation and necrosis of hippocampal CA1 and CA3 neurons were further impaired by tPA, but were preserved by the ET-1 antagonist BQ 123 and tPA-A, 296-299 a variant that is fibrinolytic but does not bind to NMDA-Rs. Expression of ET-1 was increased by stroke and potentiated by tPA but returned to sham levels by tPA-A 296-299 and the JNK antagonist SP600125. Results show that JNK releases ET-1 after stroke. Tissue-type plasminogen activator -A 296-299 prevents impairment of cerebral autoregulation and histopathology after stroke by inhibiting upregulation of ET-1. © 2017 Wiley Periodicals, Inc.

Self-Reported Stroke Symptoms Without a Prior Diagnosis of Stroke or TIA: A Powerful New Risk Factor for Stroke

PubMed Central

Kleindorfer, Dawn; Judd, Suzanne; Howard, Virginia J.; McClure, Leslie; Safford, Monika M.; Cushman, Mary; Rhodes, David; Howard, George

2011-01-01

Background and Purpose Previously in the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort, we found 18% of the stroke/TIA-free study population reported ≥ 1 stroke symptom (SS) at baseline. We sought to evaluate the additional impact of these stroke symptoms (SS) on risk for subsequent stroke. Methods REGARDS recruited 30,239 U.S. blacks and whites, aged 45+ in 2003–7, who are being followed every 6 months for events. All stroke events are physician-verified; those with prior diagnosed stroke or TIA are excluded from this analysis. At baseline, participants were asked six questions regarding stroke symptoms. Measured stroke risk factors were components of the Framingham Stroke Risk Score (FSRS). Results After excluding those with prior stroke or missing data, there were 24,412 participants in this analysis, with a median follow-up of 4.4 years. Participants were 39% black, 55% female, and had median age of 64 years. There were 381 physician-verified stroke events. The FSRS explained 72.0% of stroke risk; individual components explained between 0.2% (LVH) and 5.7% (age + race) of stroke risk. After adjustment for FSRS factors, SS were significantly related to stroke risk: for each SS reported, the risk of stroke increased by 21% per symptom. Discussion Among participants without self-reported stroke or TIA, prior SS are highly predictive of future stroke events. Compared to FSRS factors, the impact of SS on the prediction of future stroke was almost as large as the impact of smoking and hypertension, and larger than the impact of diabetes and heart disease. PMID:21921283

One-stop-shop stroke imaging with functional CT.

PubMed

Tong, Elizabeth; Komlosi, Peter; Wintermark, Max

2015-12-01

Advanced imaging techniques have extended beyond traditional anatomic imaging and progressed to dynamic, physiologic and functional imaging. Neuroimaging is no longer a mere diagnostic tool. Multimodal functional CT, comprising of NCCT, PCT and CTA, provides a one-stop-shop for rapid stroke imaging. Integrating those imaging findings with pertinent clinical information can help guide subsequent treatment decisions, medical management and follow-up imaging selection. This review article will briefly discuss the indication and utility of each modality in acute stroke imaging. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Amphetamine-associated ischemic stroke: clinical presentation and proposed pathogenesis.

PubMed

De Silva, Deidre Anne; Wong, Meng Cheong; Lee, Moi Pin; Chen, Christopher Li-Hsian; Chang, Hui Meng

2007-01-01

We report a young lady with acute left middle cerebral artery infarction after acute intake of amphetamine. This is the first case report of amphetamine-induced ischemic stroke with serial angiography and transcranial color-coded Doppler studies. The temporal sequence of stenosis of at least 3 weeks with subsequent complete resolution by 3 months and a "beaded" appearance on angiography support vasculitis or vasospasm as the pathogenesis of ischemic stroke in this patient. The presence of microembolic signals supports acute thrombosis at the site of vasculitis/vasospasm with distal embolism.

On the mechanism of X-ray production by dart leaders of lightning flashes

NASA Astrophysics Data System (ADS)

Cooray, Vernon; Dwyer, Joseph; Rakov, V.; Rahman, Mahbubur

2010-07-01

Radiation with energies up to about 250 keV associated with the dart leader phase of rocket-triggered lightning were reported by Dwyer et al. (2004). The mechanism of X-ray generation by dart leaders, however, is unknown at present. Recently, Cooray et al. (2009a) developed physical concepts and mathematical techniques necessary to calculate the electric field associated with the tip of dart leaders. We have utilized the results of these calculations together with the energy dependent frictional force on electrons, as presented by Moss et al. (2006), to evaluate the maximum energy an electron will receive in accelerating in the dart-leader-tip electric field. The main assumptions made in performing the calculations are: (a) the dart leader channel is straight and vertical; (b) the path of the electrons are straight inside the channel; and (c) the decay of the channel temperature is uniform along the length of the dart leader. In the calculation, we have taken into account the fact that the electric field is changing both in space and time and that the gas in the defunct return stroke channel is at atmospheric pressure and at elevated temperature (i.e. reduced gas density). The results of the calculation show that for a given dart leader current there is a critical defunct-return-stroke-channel temperature above which the cold electron runaway becomes feasible. For a typical dart leader, this temperature is around 2500 K. This critical temperature decreases with increase in dart leader current. Since the temperature of the defunct return stroke channel may lie in the range of 2000-4000 K, the results show that the electric field at the tip of dart leaders is capable of accelerating electrons to MeV energy levels.

Help seeking behavior and onset-to-alarm time in patients with acute stroke: sub-study of the preventive antibiotics in stroke study.

PubMed

Zock, E; Kerkhoff, H; Kleyweg, R P; van Bavel-Ta, T B V; Scott, S; Kruyt, N D; Nederkoorn, P J; van de Beek, D

2016-11-25

Patients with acute stroke often do not seek immediate medical help, which is assumed to be driven by lack of knowledge of stroke symptoms. We explored the process of help seeking behavior in patients with acute stroke, evaluating knowledge about stroke symptoms, socio-demographic and clinical characteristics, and onset-to-alarm time (OAT). In a sub-study of the Preventive Antibiotics in Stroke Study (PASS), 161 acute stroke patients were prospectively included in 3 Dutch hospitals. A semi-structured questionnaire was used to assess knowledge, recognition and interpretation of stroke symptoms. With in-depth interviews, response actions and reasons were explored. OAT was recorded and associations with socio-demographic, clinical parameters were assessed. Knowledge about stroke symptoms does not always result in correct recognition of own stroke symptoms, neither into correct interpretation of the situation and subsequent action. In our study population of 161 patients with acute stroke, median OAT was 30 min (interquartile range [IQR] 10-150 min). Recognition of one-sided weakness and/or sensory loss (p = 0.046) and adequate interpretation of the stroke situation (p = 0.003), stroke at daytime (p = 0.002), severe stroke (p = 0.003), calling the emergency telephone number (p = 0.004), and transport by ambulance (p = 0.040) were associated with shorter OAT. Help seeking behavior after acute stroke is a complex process. A shorter OAT after stroke is associated with correct recognition of one-sided weakness and/or sensory loss, adequate interpretation of the stroke situation by the patient and stroke characteristics and logistics of stroke care, but not by knowledge of stroke symptoms.

Social isolation after stroke leads to depressive-like behavior and decreased BDNF levels in mice.

PubMed

O'Keefe, Lena M; Doran, Sarah J; Mwilambwe-Tshilobo, Laetitia; Conti, Lisa H; Venna, Venugopal R; McCullough, Louise D

2014-03-01

Social isolation prior to stroke leads to poorer outcomes after an ischemic injury in both animal and human studies. However, the impact of social isolation following stroke, which may be more clinically relevant as a target for therapeutic intervention, has yet to be examined. In this study, we investigated both the sub-acute (2 weeks) and chronic (7 weeks) effects of social isolation on post-stroke functional and histological outcome. Worsened histological damage from ischemic injury and an increase in depressive-like behavior was observed in isolated mice as compared to pair-housed mice. Mice isolated immediately after stroke showed a decrease in the levels of brain-derived neurotrophic factor (BDNF). These changes, both histological and behavioral, suggest an overall negative effect of social isolation on stroke outcome, potentially contributing to post-stroke depression and anxiety. Therefore, it is important to identify patients who have perceived isolation post-stroke to hopefully prevent this exacerbation of histological damage and subsequent depression. Copyright © 2013 Elsevier B.V. All rights reserved.

Nox2 Knockout Delays Infarct Progression and Increases Vascular Recovery through Angiogenesis in Mice following Ischaemic Stroke with Reperfusion

PubMed Central

McCann, Sarah K.; Dusting, Gregory J.; Roulston, Carli L.

2014-01-01

Evidence suggests the NADPH oxidases contribute to ischaemic stroke injury and Nox2 is the most widely studied subtype in the context of stroke. There is still conjecture however regarding the benefits of inhibiting Nox2 to improve stroke outcome. The current study aimed to examine the temporal effects of genetic Nox2 deletion on neuronal loss after ischaemic stroke using knockout (KO) mice with 6, 24 and 72 hour recovery. Transient cerebral ischaemia was induced via intraluminal filament occlusion and resulted in reduced infarct volumes in Nox2 KO mice at 24 h post-stroke compared to wild-type controls. No protection was evident at either 6 h or 72 h post-stroke, with both genotypes exhibiting similar volumes of damage. Reactive oxygen species were detected using dihydroethidium and were co-localised with neurons and microglia in both genotypes using immunofluorescent double-labelling. The effect of Nox2 deletion on vascular damage and recovery was also examined 24 h and 72 h post-stroke using an antibody against laminin. Blood vessel density was decreased in the ischaemic core of both genotypes 24 h post-stroke and returned to pre-stroke levels only in Nox2 KO mice by 72 h. Overall, these results are the first to show that genetic Nox2 deletion merely delays the progression of neuronal loss after stroke but does not prevent it. Additionally, we show for the first time that Nox2 deletion increases re-vascularisation of the damaged brain by 72 h, which may be important in promoting endogenous brain repair mechanisms that rely on re-vascularisation. PMID:25375101

A Teaching Procedure for the Diatype Analyzer

ERIC Educational Resources Information Center

Pringle, Girard F.; O'Brien, Michael James

1973-01-01

The Diatype Analyzer is a motor-driven typewriting device which attaches to the carriage of the typewriter and is used to diagnose students' typewriting difficulties (rhythm, difficult strokes, concentration, carriage return, operation of the shift key or space bar) more exactly than by teacher examination. (AG)

Stroke Volume During Concomitant Apnea and Exercise: Influence of Gravity and Venous Return

NASA Astrophysics Data System (ADS)

Hoffmann, Uwe; Drager, Tobias; Steegmanns, Ansgar; Koesterer, Thomas; Linnarsson, Dag

2008-06-01

The responses of the cardiovascular system to intensive exercise (hiP) and combined stimuli by hiP and breath-hold (hiP-BH) for 20 s were examined during changing gravity (parabolic flight) and constant gravity (1g). The basic response to microgravity (μg) during low-intensity exercise was an increase in cardiac output (CO) and stroke volume (SV) as a result of augmented venous return. When onset of hiP was superimposed, the initial augmentation of CO and SV were increased further. In contrast, when BH was added, the increases of CO and SV were slowed. We propose that this was due to a transient increase of the pulmonary blood volume with the combination of μg and BH at large lung volume, creating a temporary imbalance between right ventricular input and left ventricular output. In addition, the BH- induced relative bradycardia may have contributed to a prolongation of the right-to- left indirect ventricular interdependence.

An Approach to the Lightning Overvoltage Protection of Medium Voltage Lines in Severe Lightning Areas

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

Omidiora, M. A.; Lehtonen, M.

2008-05-08

This paper deals with the effect of shield wires on lightning overvoltage reduction and the energy relief of MOV (Metal Oxide Varistor) arresters from direct strokes to distribution lines. The subject of discussion is the enhancement of lightning protection in Finnish distribution networks where lightning is most severe. The true index of lightning severity in these areas is based on the ground flash densities and return stroke data collected from the Finnish meteorological institute. The presented test case is the IEEE 34-node test feeder injected with multiple lightning strokes and simulated with the Alternative Transients Program/Electromagnetic Transients program (ATP/EMTP). Themore » response of the distribution line to lightning strokes was modeled with three different cases: no protection, protection with surge arresters and protection with a combination of shield wire and arresters. Simulations were made to compare the resulting overvoltages on the line for all the analyzed cases.« less

Gait training strategies to optimize walking ability in people with stroke: A synthesis of the evidence

PubMed Central

Tang, Pei Fang

2011-01-01

Stroke is a leading cause of long-term disability. Impairments resulting from stroke lead to persistent difficulties with walking and subsequently, improved walking ability is one of the highest priorities for people living with a stroke. In addition, walking ability has important health implications in providing protective effects against secondary complications common after a stroke such as heart disease or osteoporosis. This paper systematically reviews common gait training strategies (neurodevelopmental techniques, muscle strengthening, treadmill training, intensive mobility exercises) to improve walking ability. The results (descriptive summaries as well as pooled effect sizes) from randomized controlled trials are presented and implications for optimal gait training strategies are discussed. Novel and emerging gait training strategies are highlighted and research directions proposed to enable the optimal recovery and maintenance of walking ability. PMID:17939776

Ball Machine Usage in Tennis: Movement Initiation and Swing Timing While Returning Balls from a Ball Machine and from a Real Server

PubMed Central

Carboch, Jan; Süss, Vladimir; Kocib, Tomas

2014-01-01

Practicing with the use of a ball machine could handicap a player compared to playing against an actual opponent. Recent studies have shown some differences in swing timing and movement coordination, when a player faces a ball projection machine as opposed to a human opponent. We focused on the time of movement initiation and on stroke timing during returning tennis serves (simulated by a ball machine or by a real server). Receivers’ movements were measured on a tennis court. In spite of using a serving ball speed from 90 kph to 135 kph, results showed significant differences in movement initiation and backswing duration between serves received from a ball machine and serves received from a real server. Players had shorter movement initiation when they faced a ball machine. Backswing duration was longer for the group using a ball machine. That demonstrates different movement timing of tennis returns when players face a ball machine. Use of ball machines in tennis practice should be limited as it may disrupt stroke timing. Key points Players have shorter initial move time when they are facing the ball machine. Using the ball machine results in different swing timing and movement coordination. The use of the ball machine should be limited. PMID:24790483

Ball machine usage in tennis: movement initiation and swing timing while returning balls from a ball machine and from a real server.

PubMed

Carboch, Jan; Süss, Vladimir; Kocib, Tomas

2014-05-01

Practicing with the use of a ball machine could handicap a player compared to playing against an actual opponent. Recent studies have shown some differences in swing timing and movement coordination, when a player faces a ball projection machine as opposed to a human opponent. We focused on the time of movement initiation and on stroke timing during returning tennis serves (simulated by a ball machine or by a real server). Receivers' movements were measured on a tennis court. In spite of using a serving ball speed from 90 kph to 135 kph, results showed significant differences in movement initiation and backswing duration between serves received from a ball machine and serves received from a real server. Players had shorter movement initiation when they faced a ball machine. Backswing duration was longer for the group using a ball machine. That demonstrates different movement timing of tennis returns when players face a ball machine. Use of ball machines in tennis practice should be limited as it may disrupt stroke timing. Key pointsPlayers have shorter initial move time when they are facing the ball machine.Using the ball machine results in different swing timing and movement coordination.The use of the ball machine should be limited.

Ontogenetic changes in the olfactory antennules of the shore crab, Hemigrapsus oregonensis, maintain sniffing function during growth

PubMed Central

Waldrop, Lindsay D.; Hann, Miranda; Henry, Amy K.; Kim, Agnes; Punjabi, Ayesha; Koehl, M. A. R.

2015-01-01

Malacostracan crustaceans capture odours using arrays of chemosensory hairs (aesthetascs) on antennules. Lobsters and stomatopods have sparse aesthetascs on long antennules that flick with a rapid downstroke when water flows between the aesthetascs and a slow return stroke when water is trapped within the array (sniffing). Changes in velocity only cause big differences in flow through an array in a critical range of hair size, spacing and speed. Crabs have short antennules bearing dense arrays of flexible aesthetascs that splay apart during downstroke and clump together during return. Can crabs sniff, and when during ontogeny are they big enough to sniff? Antennules of Hemigrapsus oregonensis representing an ontogenetic series from small juveniles to adults were used to design dynamically scaled physical models. Particle image velocimetry quantified fluid flow through each array and showed that even very small crabs capture a new water sample in their arrays during the downstroke and retain that sample during return stroke. Comparison with isometrically scaled antennules suggests that reduction in aesthetasc flexural stiffness during ontogeny, in addition to increase in aesthetasc number and decrease in relative size, maintain sniffing as crabs grow. Sniffing performance of intermediate-sized juveniles was worse than for smaller and larger crabs. PMID:25411408

Ontogenetic changes in the olfactory antennules of the shore crab, Hemigrapsus oregonensis, maintain sniffing function during growth.

PubMed

Waldrop, Lindsay D; Hann, Miranda; Henry, Amy K; Kim, Agnes; Punjabi, Ayesha; Koehl, M A R

2015-01-06

Malacostracan crustaceans capture odours using arrays of chemosensory hairs (aesthetascs) on antennules. Lobsters and stomatopods have sparse aesthetascs on long antennules that flick with a rapid downstroke when water flows between the aesthetascs and a slow return stroke when water is trapped within the array (sniffing). Changes in velocity only cause big differences in flow through an array in a critical range of hair size, spacing and speed. Crabs have short antennules bearing dense arrays of flexible aesthetascs that splay apart during downstroke and clump together during return. Can crabs sniff, and when during ontogeny are they big enough to sniff? Antennules of Hemigrapsus oregonensis representing an ontogenetic series from small juveniles to adults were used to design dynamically scaled physical models. Particle image velocimetry quantified fluid flow through each array and showed that even very small crabs capture a new water sample in their arrays during the downstroke and retain that sample during return stroke. Comparison with isometrically scaled antennules suggests that reduction in aesthetasc flexural stiffness during ontogeny, in addition to increase in aesthetasc number and decrease in relative size, maintain sniffing as crabs grow. Sniffing performance of intermediate-sized juveniles was worse than for smaller and larger crabs. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Self-report of stroke, transient ischemic attack, or stroke symptoms and risk of future stroke in the REasons for Geographic and Racial Differences in Stroke (REGARDS) Study

PubMed Central

Judd, Suzanne E; Kleindorfer, Dawn O; McClure, Leslie A; Rhodes, J. David; Howard, George; Cushman, Mary; Howard, Virginia J.

2013-01-01

Background and Purpose History of stroke and Transient Ischemic Attack (TIA) are documented risk factors for subsequent stroke and all-cause mortality. Recent reports suggest increased risk among those reporting stroke symptoms absent stroke or TIA. However, the relative magnitude of increased stroke risk has not been described across the symptomatic spectrum: 1) asymptomatic (Asx), 2) stroke symptoms only (SS), 3) TIA, 4) stroke in the distant past (DS), and 5) recent stroke (RS). Methods Between 2003–2007 the REasons for Geographic And Racial Differences in Stroke (REGARDS) study enrolled 30,239 black and white Americans aged 45+. DS and RS were defined as self-report of physician diagnosis of stroke >5 or <5 years before baseline, respectively. SS was defined as a history of any of six sudden onset stroke symptoms absent TIA/stroke diagnosis. Kaplan-Meier and proportional hazards analysis were used to contrast stroke risk differences. Results Over 5.0 ± 1.72 years of follow up, 737 strokes were validated. Compared to Asx persons, those with SS, TIA, DS and RS all had increased risk of future stroke. After adjustment for age, race, sex, income, education, alcohol intake, current smoking, and a history of diabetes, hypertension, myocardial infarction, atrial fibrillation, and dyslipidemia, there was 1.20-fold (not statistically significant) increased stroke risk for SS (95% CI 0.96, 1.51), 1.73-fold for TIA (95% CI 1.27, 2.36), 2.23-fold for DS (95% CI 1.61, 3.09) and 2.85-fold for RS (95% CI 2.16, 3.76). Discussion Results suggest a spectrum of risk from stroke symptoms to TIA, distant stroke, and recent stroke, and imply a need for establishing these categories in health screenings to manage risk for future stroke, reinforcing the clinical importance of stroke history including the presence of stroke symptoms. PMID:23233382

High-speed plasma imaging: A lightning bolt

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

Wurden, G.A.; Whiteson, D.O.

Using a gated intensified digital Kodak Ektapro camera system, the authors captured a lightning bolt at 1,000 frames per second, with 100-{micro}s exposure time on each consecutive frame. As a thunder storm approaches while darkness descended (7:50 pm) on July 21, 1994, they photographed lightning bolts with an f22 105-mm lens and 100% gain on the intensified camera. This 15-frame sequence shows a cloud to ground stroke at a distance of about 1.5 km, which has a series of stepped leaders propagating downwards, following by the upward-propagating main return stroke.

Exertional Heat Stroke and American Football: What the Team Physician Needs to Know.

PubMed

Sylvester, Jillian E; Belval, Luke N; Casa, Douglas J; O'Connor, Francis G

Football is recognized as a leading contributor to sports injury secondary to the contact collision nature of the endeavor. While direct deaths from head and spine injury remain a significant contributor to the number of catastrophic injuries, indirect deaths (systemic failure) predominate. Exertional heat stroke has emerged as one of the leading indirect causes of death in high school and collegiate football. This review details for the team physician the unique challenge of exercising in the heat to the football player, and the prevention, diagnosis, management, and return-to-play issues pertinent to exertional heat illnesses.

Delay time between onset of ischemic stroke and hospital arrival.

PubMed

Biller, J; Patrick, J T; Shepard, A; Adams, H P

1993-01-01

Some current experimental protocols for acute ischemic stroke require the initiation of treatment within hours of the onset of stroke symptoms. We prospectively evaluated 30 patients with acute ischemic stroke based on clinical and computed tomography findings. The time between the onset of stroke symptoms and arrival in the emergency room and subsequently on the stroke service was determined. Within 3, 6,12, and 24 h of the onset of stroke symptoms, 16 (53%), 19 (63%), 22 (73%), and 25 (83%) patients had arrived at the emergency room and 0 (0%), 4 (13%), 14 (47%), and 22 (73%) of them on the stroke service, respectively. From the onset of stroke symptoms, the mean arrival time to the emergency room was 24 h (range, 30 min to 144 h) and to the stroke service was 61 h (range, 4-150 h). The mean time between arrival in the emergency room and stroke service was 8.6 h (range, 0-47 h). Even though 53% and 63% of our patients arrived at the emergency room within 3 and 6 h of the onset of stroke symptoms, only 0% and 13% of them arrived on the stroke service within the same time period for the initiation of treatment, respectively. Thus, in order for more patients to qualify for current experimental protocols, they must arrive on the stroke service more quickly or treatment must be initiated in the emergency room. Copyright © 1993. Published by Elsevier Inc.

Methodology for a Community Based Stroke Preparedness Intervention: The ASPIRE Study

PubMed Central

Boden-Albala, Bernadette; Edwards, Dorothy F.; Clair, Shauna St; Wing, Jeffrey J; Fernandez, Stephen; Gibbons, Chris; Hsia, Amie W.; Morgenstern, Lewis B.; Kidwell, Chelsea S.

2014-01-01

Background and Purpose Acute stroke education has focused on stroke symptom recognition. Lack of education about stroke preparedness and appropriate actions may prevent people from seeking immediate care. Few interventions have rigorously evaluated preparedness strategies in multiethnic community settings. Methods The Acute Stroke Program of Interventions Addressing Racial and Ethnic Disparities (ASPIRE) project is a multi-level program utilizing a community engaged approach to stroke preparedness targeted to underserved black communities in the District of Columbia (DC). This intervention aimed to decrease acute stroke presentation times and increase intravenous tissue plasminogen activator (IV tPA) utilization for acute ischemic stroke. Results Phase 1 included: 1) enhancement of EMS focus on acute stroke; 2) hospital collaborations to implement and/or enrich acute stroke protocols and transition DC hospitals toward Primary Stroke Center certification; and 3) pre-intervention acute stroke patient data collection in all 7 acute care DC hospitals. A community advisory committee, focus groups, and surveys identified perceptions of barriers to emergency stroke care. Phase 2 included a pilot intervention and subsequent citywide intervention rollout. A total of 531 community interventions were conducted with over 10,256 participants reached; 3289 intervention evaluations were performed, and 19,000 preparedness bracelets and 14,000 stroke warning magnets were distributed. Phase 3 included an evaluation of EMS and hospital processes for acute stroke care and a yearlong post-intervention acute stroke data collection period to assess changes in IV tPA utilization. Conclusions We report the methods, feasibility, and pre-intervention data collection efforts of the ASPIRE intervention. PMID:24876243

Predictive variables for mortality after acute ischemic stroke.

PubMed

Carter, Angela M; Catto, Andrew J; Mansfield, Michael W; Bamford, John M; Grant, Peter J

2007-06-01

Stroke is a major healthcare issue worldwide with an incidence comparable to coronary events, highlighting the importance of understanding risk factors for stroke and subsequent mortality. In the present study, we determined long-term (all-cause) mortality in 545 patients with ischemic stroke compared with a cohort of 330 age-matched healthy control subjects followed up for a median of 7.4 years. We assessed the effect of selected demographic, clinical, biochemical, hematologic, and hemostatic factors on mortality in patients with ischemic stroke. Stroke subtype was classified according to the Oxfordshire Community Stroke Project criteria. Patients who died 30 days or less after the acute event (n=32) were excluded from analyses because this outcome is considered to be directly attributable to the acute event. Patients with ischemic stroke were at more than 3-fold increased risk of death compared with the age-matched control cohort. In multivariate analyses, age, stroke subtype, atrial fibrillation, and previous stroke/transient ischemic attack were predictive of mortality in patients with ischemic stroke. Albumin and creatinine and the hemostatic factors von Willebrand factor and beta-thromboglobulin were also predictive of mortality in patients with ischemic stroke after accounting for demographic and clinical variables. The results indicate that subjects with acute ischemic stroke are at increased risk of all-cause mortality. Advancing age, large-vessel stroke, atrial fibrillation, and previous stroke/transient ischemic attack predict mortality; and analysis of albumin, creatinine, von Willebrand factor, and beta-thromboglobulin will aid in the identification of patients at increased risk of death after stroke.

Mechanical Thrombectomy in Elderly Stroke Patients with Mild-to-Moderate Baseline Disability.

PubMed

Slawski, Diana E; Salahuddin, Hisham; Shawver, Julie; Kenmuir, Cynthia L; Tietjen, Gretchen E; Korsnack, Andrea; Zaidi, Syed F; Jumaa, Mouhammad A

2018-04-01

The number of elderly patients suffering from ischemic stroke is rising. Randomized trials of mechanical thrombectomy (MT) generally exclude patients over the age of 80 years with baseline disability. The aim of this study was to understand the efficacy and safety of MT in elderly patients, many of whom may have baseline impairment. Between January 2015 and April 2017, 96 patients ≥80 years old who underwent MT for stroke were selected for a chart review. The data included baseline characteristics, time to treatment, the rate of revascularization, procedural complications, mortality, and 90-day good outcome defined as a modified Rankin Scale (mRS) score of 0-2 or return to baseline. Of the 96 patients, 50 had mild baseline disability (mRS score 0-1) and 46 had moderate disability (mRS score 2-4). Recanalization was achieved in 84% of the patients, and the rate of symptomatic hemorrhage was 6%. At 90 days, 34% of the patients had a good outcome. There were no significant differences in good outcome between those with mild and those with moderate baseline disability (43 vs. 24%, p = 0.08), between those aged ≤85 and those aged > 85 years (40.8 vs. 26.1%, p = 0.19), and between those treated within and those treated beyond 8 h (39 vs. 20%, p = 0.1). The mortality rate was 38.5% at 90 days. The Alberta Stroke Program Early CT Score (ASPECTS) and the National Institutes of Health Stroke Scale (NIHSS) predicted good outcome regardless of baseline disability ( p < 0.001 and p = 0.009, respectively). Advanced age, baseline disability, and delayed treatment are associated with sub-optimal outcomes after MT. However, redefining good outcome to include return to baseline functioning demonstrates that one-third of this patient population benefits from MT, suggesting the real-life utility of this treatment.

“Living With a Ball and Chain”: The Experience of Stroke for Individuals and Their Caregivers in Rural Appalachian Kentucky

PubMed Central

Danzl, Megan M.; Hunter, Elizabeth G.; Campbell, Sarah; Sylvia, Violet; Kuperstein, Janice; Maddy, Katherine; Harrison, Anne

2013-01-01

Purpose Individuals in rural Appalachian Kentucky face health disparities and are at increased risk for negative health outcomes and poor quality of life secondary to stroke. The purpose of this study is to describe the experience of stroke for survivors and their caregivers in this region. A description of their experiences is paramount to developing tailored interventions and ultimately improving health care and support. Methods An interprofessional research team used a qualitative descriptive study design and interviewed 13 individuals with stroke and 12 caregivers, representing 10 rural Appalachian Kentucky counties. The transcripts were analyzed using qualitative content analysis. Findings A descriptive summary of the participants’ experience of stroke is presented within the following structure: 1) Stroke onset, 2) Transition through the health care continuum (including acute care, inpatient rehabilitation, and community-based rehabilitation), and 3) Reintegration into life and rural communities. Conclusions The findings provide insight for rural health care providers and community leaders to begin to understand the experience of stroke in terms of stroke onset, transition through the health care continuum, return to home, and community reintegration. An understanding of these experiences may lead to discussions of how to improve service provision, facilitate reintegration, support positive health outcomes and improve quality of life for stroke survivors and their caregivers. The findings also indicate areas in need of future research including investigation of the effects of support groups, local health navigators to improve access to information and services, involvement of faith communities, proactive screening for management of mental health needs, and caregiver respite services. PMID:24088211

An International Standard Set of Patient-Centered Outcome Measures After Stroke.

PubMed

Salinas, Joel; Sprinkhuizen, Sara M; Ackerson, Teri; Bernhardt, Julie; Davie, Charlie; George, Mary G; Gething, Stephanie; Kelly, Adam G; Lindsay, Patrice; Liu, Liping; Martins, Sheila C O; Morgan, Louise; Norrving, Bo; Ribbers, Gerard M; Silver, Frank L; Smith, Eric E; Williams, Linda S; Schwamm, Lee H

2016-01-01

Value-based health care aims to bring together patients and health systems to maximize the ratio of quality over cost. To enable assessment of healthcare value in stroke management, an international standard set of patient-centered stroke outcome measures was defined for use in a variety of healthcare settings. A modified Delphi process was implemented with an international expert panel representing patients, advocates, and clinical specialists in stroke outcomes, stroke registers, global health, epidemiology, and rehabilitation to reach consensus on the preferred outcome measures, included populations, and baseline risk adjustment variables. Patients presenting to a hospital with ischemic stroke or intracerebral hemorrhage were selected as the target population for these recommendations, with the inclusion of transient ischemic attacks optional. Outcome categories recommended for assessment were survival and disease control, acute complications, and patient-reported outcomes. Patient-reported outcomes proposed for assessment at 90 days were pain, mood, feeding, selfcare, mobility, communication, cognitive functioning, social participation, ability to return to usual activities, and health-related quality of life, with mobility, feeding, selfcare, and communication also collected at discharge. One instrument was able to collect most patient-reported subdomains (9/16, 56%). Minimum data collection for risk adjustment included patient demographics, premorbid functioning, stroke type and severity, vascular and systemic risk factors, and specific treatment/care-related factors. A consensus stroke measure Standard Set was developed as a simple, pragmatic method to increase the value of stroke care. The set should be validated in practice when used for monitoring and comparisons across different care settings. © 2015 The Authors.

Utility loss and indirect costs after stroke in Sweden.

PubMed

Lindgren, Peter; Glader, Eva-Lotta; Jönsson, Bengt

2008-04-01

Currently little data exist on the development of quality of life over time in patients suffering from stroke, in particular using instruments that can be adapted in economic studies. The purpose of the study was to assess the utility loss and indirect costs following a stroke in Sweden. A cross-sectional mail survey. In collaboration with the National Stroke registry (RIKS-STROKE), a questionnaire consisting of the EuroQol-5D and questions regarding the present working status and the status prior to the stroke was mailed to patients below 76 years of age at six participating centres. The questionnaire was mailed to 393 patients in total, divided into groups with 3, 6, 9 or 12 months having passed since the stroke. The EuroQol-5D scores were converted to utility scores using the UK social tariff. Indirect costs were valued according to the average salary+employer contributions. A total of 275 questionnaires (70%) were returned. Utility scores were similar over time: 0.65, 0.75, 0.63, and 0.67 at 3, 6, 9 and 12 months, respectively. Regression analyses revealed a tendency for lower utility scores among women, but no significant differences overall. Among patients in the working ages, a stroke caused 18.5 work weeks lost, corresponding to an indirect cost of 120,000 Swedish Kronor (SEK) (13,200euro, 95% confidence interval 82,541-160,050 SEK, 9080-17 605euro). Stroke causes a significant reduction in utility and causes high indirect costs. A substantial improvement was not noted over time, which is important to consider in economic models.

Tracks of a non-main path traveler: 2011 Thomas Willis Lecture.

PubMed

Hallenbeck, John M

2012-02-01

After an unconventional beginning in stroke research, I veered off the main path repeatedly to view problems from a different perspective. In this lecture summary, I would like to return to several points along the byways that led to research with some continuity.

Cardiovascular consequences of bed rest: effect on maximal oxygen uptake

NASA Technical Reports Server (NTRS)

Convertino, V. A.

1997-01-01

Maximal oxygen uptake (VO2max) is reduced in healthy individuals confined to bed rest, suggesting it is independent of any disease state. The magnitude of reduction in VO2max is dependent on duration of bed rest and the initial level of aerobic fitness (VO2max), but it appears to be independent of age or gender. Bed rest induces an elevated maximal heart rate which, in turn, is associated with decreased cardiac vagal tone, increased sympathetic catecholamine secretion, and greater cardiac beta-receptor sensitivity. Despite the elevation in heart rate, VO2max is reduced primarily from decreased maximal stroke volume and cardiac output. An elevated ejection fraction during exercise following bed rest suggests that the lower stroke volume is not caused by ventricular dysfunction but is primarily the result of decreased venous return associated with lower circulating blood volume, reduced central venous pressure, and higher venous compliance in the lower extremities. VO2max, stroke volume, and cardiac output are further compromised by exercise in the upright posture. The contribution of hypovolemia to reduced cardiac output during exercise following bed rest is supported by the close relationship between the relative magnitude (% delta) and time course of change in blood volume and VO2max during bed rest, and also by the fact that retention of plasma volume is associated with maintenance of VO2max after bed rest. Arteriovenous oxygen difference during maximal exercise is not altered by bed rest, suggesting that peripheral mechanisms may not contribute significantly to the decreased VO2max. However reduction in baseline and maximal muscle blood flow, red blood cell volume, and capillarization in working muscles represent peripheral mechanisms that may contribute to limited oxygen delivery and, subsequently, lowered VO2max. Thus, alterations in cardiac and vascular functions induced by prolonged confinement to bed rest contribute to diminution of maximal oxygen uptake and reserve capacity to perform physical work.

Creation and preliminary validation of the screening for self-medication safety post-stroke scale (S-5).

PubMed

Kaizer, Franceen; Kim, Angela; Van, My Tram; Korner-Bitensky, Nicol

2010-03-01

Patients with stroke should be screened for safety prior to starting a self-medication regime. An extensive literature review revealed no standardized self-medication tool tailored to the multi-faceted needs of the stroke population. The aim of this study was to create and validate a condition-specific tool to be used in screening for self-medication safety in individuals with stroke. Items were generated using expert consultation and review of the existing tools. The draft tool was pilot-tested on expert stroke clinicians to receive feedback on content, clarity, optimal cueing and domain omissions. The final version was piloted on patients with stroke using a structured interviewer-administered interview. The tool was progressively refined and validated according to feedback from the 11 expert reviewers. The subsequent version was piloted on patients with stroke. The final version includes 16 questions designed to elicit information on 5 domains: cognition, communication, motor, visual-perception and, judgement/executive function/self-efficacy. The Screening for Safe Self-medication post-Stroke Scale (S-5) has been created and validated for use by health professionals to screen self-medication safety readiness of patients after stroke. Its use should also help to guide clinicians' recommendations and interventions aimed at enhancing self-medication post-stroke.

Autonomic Nervous System and Stress to Predict Secondary Ischemic Events after Transient Ischemic Attack or Minor Stroke: Possible Implications of Heart Rate Variability.

PubMed

Guan, Ling; Collet, Jean-Paul; Mazowita, Garey; Claydon, Victoria E

2018-01-01

Transient ischemic attack (TIA) and minor stroke have high risks of recurrence and deterioration into severe ischemic strokes. Risk stratification of TIA and minor stroke is essential for early effective treatment. Traditional tools have only moderate predictive value, likely due to their inclusion of the limited number of stroke risk factors. Our review follows Hans Selye's fundamental work on stress theory and the progressive shift of the autonomic nervous system (ANS) from adaptation to disease when stress becomes chronic. We will first show that traditional risk factors and acute triggers of ischemic stroke are chronic and acute stress factors or "stressors," respectively. Our first review shows solid evidence of the relationship between chronic stress and stroke occurrence. The stress response is tightly regulated by the ANS whose function can be assessed with heart rate variability (HRV). Our second review demonstrates that stress-related risk factors of ischemic stroke are correlated with ANS dysfunction and impaired HRV. Our conclusions support the idea that HRV parameters may represent the combined effects of all body stressors that are risk factors for ischemic stroke and, thus, may be of important predictive value for the risk of subsequent ischemic events after TIA or minor stroke.

Autonomic Nervous System and Stress to Predict Secondary Ischemic Events after Transient Ischemic Attack or Minor Stroke: Possible Implications of Heart Rate Variability

PubMed Central

Guan, Ling; Collet, Jean-Paul; Mazowita, Garey; Claydon, Victoria E.

2018-01-01

Transient ischemic attack (TIA) and minor stroke have high risks of recurrence and deterioration into severe ischemic strokes. Risk stratification of TIA and minor stroke is essential for early effective treatment. Traditional tools have only moderate predictive value, likely due to their inclusion of the limited number of stroke risk factors. Our review follows Hans Selye’s fundamental work on stress theory and the progressive shift of the autonomic nervous system (ANS) from adaptation to disease when stress becomes chronic. We will first show that traditional risk factors and acute triggers of ischemic stroke are chronic and acute stress factors or “stressors,” respectively. Our first review shows solid evidence of the relationship between chronic stress and stroke occurrence. The stress response is tightly regulated by the ANS whose function can be assessed with heart rate variability (HRV). Our second review demonstrates that stress-related risk factors of ischemic stroke are correlated with ANS dysfunction and impaired HRV. Our conclusions support the idea that HRV parameters may represent the combined effects of all body stressors that are risk factors for ischemic stroke and, thus, may be of important predictive value for the risk of subsequent ischemic events after TIA or minor stroke. PMID:29556209

Meta-Analysis of Perioperative Stroke and Mortality in Transcatheter Aortic Valve Implantation.

PubMed

Muralidharan, Aditya; Thiagarajan, Karthy; Van Ham, Raymond; Gleason, Thomas G; Mulukutla, Suresh; Schindler, John T; Jeevanantham, Vinodh; Thirumala, Parthasarathy D

2016-10-01

Transcatheter aortic valve implantation (TAVI) is a rapidly evolving safe method with decreasing incidence of perioperative stroke. There is a void in literature concerning the impact of stroke after TAVI in predicting 30-day stroke-related mortality. The primary aim of this meta-analysis was to determine whether perioperative stroke increases risk of stroke-related mortality after TAVI. Online databases, using relevant keywords, and additional related records were searched to retrieve articles involving TAVI and stroke after TAVI. Data were extracted from the finalized studies and analyzed to generate a summary odds ratio (OR) of stroke-related mortality after TAVI. The stroke rate and stroke-related mortality rate in the total patient population were 3.07% (893 of 29,043) and 12.27% (252 of 2,053), respectively. The all-cause mortality rate was 7.07% (2,053 of 29,043). Summary OR of stroke-related mortality after TAVI was estimated to be 6.45 (95% confidence interval 3.90 to 10.66, p <0.0001). Subgroup analyses were performed among age, approach, and valve type. Only 1 subgroup, transapical TAVI, was not significantly associated with stroke-related mortality (OR 1.97, 95% confidence interval, 0.43 to 7.43, p = 0.42). A metaregression was conducted among females, New York Heart Association class III/IV status, previous stroke, valve type, and implantation route. All failed to exhibit any significant associations with the OR. In conclusion, perioperative strokes after TAVI are associated with >6 times greater risk of 30-day stroke-related mortality. Transapical TAVI is not associated with increased stroke-related mortality in patients who suffer from perioperative stroke. Preventative measures need to be taken to alleviate the elevated rates of stroke after TAVI and subsequent direct mortality. Copyright © 2016 Elsevier Inc. All rights reserved.

Self-report of stroke, transient ischemic attack, or stroke symptoms and risk of future stroke in the REasons for Geographic And Racial Differences in Stroke (REGARDS) study.

PubMed

Judd, Suzanne E; Kleindorfer, Dawn O; McClure, Leslie A; Rhodes, J David; Howard, George; Cushman, Mary; Howard, Virginia J

2013-01-01

History of stroke and transient ischemic attack (TIA) are documented risk factors for subsequent stroke and all-cause mortality. Recent reports suggest increased risk among those reporting stroke symptoms absent stroke or TIA. However, the relative magnitude of increased stroke risk has not been described across the symptomatic spectrum: (1) asymptomatic, (2) stroke symptoms (SS) only, (3) TIA, (4) distant stroke (DS), and (5) recent stroke (RS). Between 2003 and 2007, the REasons for Geographic And Racial Differences in Stroke (REGARDS) study enrolled 30 239 black and white Americans ≥45 years of age. DS and RS were defined as self-report of physician diagnosis of stroke >5 or <5 years before baseline, respectively. SS was defined as a history of any of 6 sudden onset stroke symptoms absent TIA/stroke diagnosis. Kaplan-Meier and proportional hazards analysis were used to contrast stroke risk differences. Over 5.0±1.72 years of follow-up, 737 strokes were validated. Compared with asymptomatic persons, those with SS, TIA, DS, and RS all had increased risk of future stroke. After adjustment for age, race, sex, income, education, alcohol intake, current smoking, and a history of diabetes mellitus, hypertension, myocardial infarction, atrial fibrillation, and dyslipidemia, there was 1.20-fold (not statistically significant) increased stroke risk for SS (95% CI, 0.96-1.51), 1.73-fold for TIA (95% CI, 1.27-2.36), 2.23-fold for DS (95% CI, 1.61- 3.09), and 2.85-fold for RS (95% CI, 2.16-3.76). Results suggest a spectrum of risk from stroke symptoms to TIA, DS, and RS, and imply a need for establishing these categories in health screenings to manage risk for future stroke, reinforcing the clinical importance of stroke history including the presence of stroke symptoms.

Recovered vs. not-recovered from post-stroke aphasia: The contributions from the dominant and non-dominant hemispheres

PubMed Central

Szaflarski, Jerzy P.; Allendorfer, Jane B.; Banks, Christi; Vannest, Jennifer; Holland, Scott K.

2013-01-01

Purpose Several adult studies have documented the importance of the peri-stroke areas to aphasia recovery. But, studies examining the differences in patterns of cortical participation in language comprehension in patients who have (LMCA-R) or have not recovered (LMCA-NR) from left middle cerebral artery infarction have not been performed up to date. Methods In this study, we compare cortical correlates of language comprehension using fMRI and semantic decision/tone decision task in 9 LMCA-R and 18 LMCA-NR patients matched at the time of stroke for age and handedness. We examine the cortical correlates of language performance by correlating intra- and extra-scanner measures of linguistic performance with fMRI activation and stroke volumes. Results Our analyses show that LMCA-R at least 1 year after stroke show a return to typical fMRI language activation patterns and that there is a compensatory reorganization of language function in LMCA-NR patients with shifts to the right hemispheric brain regions. Further, with increasing strength of the left-hemispheric fMRI signal shift there are associated improvements in performance as tested with standardized linguistic measures. A negative correlation between the size of the stroke and performance on some of the linguistic tests is also observed. Conclusions This right-hemispheric shift as a mechanism of post-stroke recovery in adults appears to be an ineffective mode of language function recovery with increasing right-hemispheric shift associated with lower language performance. Thus, normalization of the post-stroke language activation patterns is needed for better language performance while shifts of the activation patterns to the non-dominant (right) hemisphere and/or large stroke size are associated with decreased linguistic abilities after stroke. PMID:23482065

Sexual function in post-stroke patients: considerations for rehabilitation.

PubMed

Rosenbaum, Talli; Vadas, Dor; Kalichman, Leonid

2014-01-01

While the rehabilitation goals of post-stroke patients include improving quality of life and returning to functional activities, the extent to which sexual activity is addressed as part of the standard rehabilitation process is unknown. Moreover, the specific sexual concerns of stroke patients, including the effect of stroke on intimate relationships and sexuality of the partner, the ability to physically engage in sex, and the effect of psychological components such as role identity, depression, and anxiety on sexuality, all warrant examination by rehabilitation professionals. The aim of this study is to examine the existing literature on sexuality and stroke patients in order to better understand how the sexual lives of stroke patients and their partners are affected and to provide recommendations to rehabilitation professionals for addressing sexuality as part of treatment. Narrative review, PubMed, PEDro, ISI Web of Science, and Google Scholar databases (inception-December 2012) were searched for the key words "stroke," "sexual dysfunction," "sexuality," "quality of life," and their combination. All relevant articles in English and secondary references were reviewed. We report the results of the literature review. Sexual dysfunction and decreased sexual satisfaction are common in the post-stroke population and are related to physical, psychosocial, and relational factors. However, they are not adequately addressed in post-stroke rehabilitation. As sexual function is an important component to quality of life and activities of daily living, physicians and rehabilitation specialists, including physical, occupational, and speech therapists, should receive training in addressing sexuality in the treatment of post-stroke patients. Sexologists and sex therapists should be an integral part of the rehabilitation team. © 2013 International Society for Sexual Medicine.

Thromboembolic Complications Following Trauma

DTIC Science & Technology

2009-12-01

subsequent neurologic deficit from these injuries approaches an inci- dence of 20 to 30 percent, the overall rate of stroke in the total trauma...investigating stroke and neurologic outcomes in blunt cerebrovascular injuries (BCVIs). In contrast, few reports of MI or mesenteric thrombosis in the...prohemostatic agents in uncontrolled studies of severely injured patients will only confuse rather than enlighten this area of research. No single paper has

Patients' expectations of coming home with Very Early Supported Discharge and home rehabilitation after stroke - an interview study.

PubMed

Nordin, Åsa; Sunnerhagen, Katharina S; Axelsson, Åsa B

2015-11-16

An Early Supported Discharge (ESD) and rehabilitation from a coordinated team in the home environment is recommended in several high-income countries for patients with mild to moderate symptoms after stroke. Returning home from the hospital takes place very early in Sweden today (12 days post stroke), thus the term Very Early Supported Discharge (VESD) is used in the current study. The aim of this study was to describe patients' expectations of coming home very early after stroke with support and rehabilitations at home. This is an interview study nested within a randomized controlled trial; Gothenburg Very Early Supported Discharge (GOTVED), comparing VESD containing a home rehabilitation intervention from a coordinated team to conventional care after stroke. Ten participants (median age 69) with mild to moderate stroke symptoms (NHISS 0 to 8 points) were recruited from the intervention group in GOTVED. Interviews were conducted 0-5 days before discharge and the material was analyzed with qualitative content analysis. Four main categories containing 11 subcategories were found. The VESD team was expected to provide "Support towards independency", by helping the participants to manage and feel safe at home as well as to regain earlier abilities. The very early discharge gave rise to expectations of coming home to "A new and unknown situation", causing worries not to manage at home and to leave the safe environment at the ward. A fear to suffer a recurrent stroke when being out of reach of immediate professional help was also pronounced. In contrast to these feelings of insecurity and fear, "Returning to one's own setting" described the participants longing home, where they would become autonomous and capable people again. They expected this to facilitate recovery and rehabilitation. "A new everyday life" waited for the participants at home and this was expected to be challenging. Different strategies to deal with these challenges were described. The participants described mixed expectations such as insecurity and fear, and on the other hand, longing to come home. Moreover, they had a high degree of confidence in the expected support of the VESD team. The health professionals at the hospital may build on this trust to reduce the patients' insecurity for coming home. In addition, it may be beneficial to explore the patients' expectations thoroughly in front of discharge, as certain feelings and thoughts could complicate or support the home coming process. Thus, a greater attention on such expectations may facilitate the patient's transition from hospital to home after stroke.

The importance of being elastic: deflection of a badminton racket during a stroke.

PubMed

Kwan, Maxine; Rasmussen, John

2010-03-01

The deflection profiles of a badminton racket during strokes performed by elite and world-class badminton players were recorded by strain gauges and subsequently analysed to determine the role of shaft stiffness in racket performance. Deflection behaviour was consistent in all strokes across all players, suggesting a controlled use of racket elasticity. In addition, all impacts occurred within 100 ms of each other, a duration in which deflection velocity provides an increase in racket velocity, indicating that the players were able to use racket elasticity to their advantage. Since deflection behaviour is a product of the racket-player interaction, further work is required to determine the effects of different racket properties and player techniques on the elastic response of rackets during strokes.

Patent Foramen Ovale Closure in the Setting of Cryptogenic Stroke: A Meta-Analysis of Five Randomized Trials.

PubMed

Garg, Lohit; Haleem, Affan; Varade, Shweta; Sivakumar, Keithan; Shah, Mahek; Patel, Brijesh; Agarwal, Manyoo; Agrawal, Sahil; Leary, Megan; Kluck, Bryan

2018-05-24

The clinical benefit of patent foramen ovale (PFO) closure after cryptogenic stroke has been a topic of debate for decades. Recently, 3 randomized controlled trials of PFO closure in patients with cryptogenic stroke demonstrated a significantly reduced risk of recurrent stroke compared with standard medical therapy alone. This meta-analysis was performed to clarify the efficacy of PFO closure for future stroke prevention in this population. A systematic literature search was undertaken. Published pooled data from 5 large randomized clinical trials (CLOSE, RESPECT, Gore REDUCE, CLOSURE I, and PC) were combined and then subsequently analyzed. Enrolled patients with cryptogenic stroke were assigned to receive standard medical care or to undergo endovascular PFO closure, with a primary outcome of reduction in stroke recurrence rate. Secondary outcomes included rates of transient ischemic attack (TIA), composite outcome of stroke, TIA, and death from all causes, and rates of atrial fibrillation events. We analyzed data for 3412 patients. Transcatheter PFO closure resulted in a statistically significant reduced rate of recurrent stroke, compared with medication alone. Patients undergoing closure were 58% less likely to have another stroke. The number needed to treat with PFO closure to reduce recurrent stroke for 1 patient was 40. Endovascular PFO closure was associated with a reduced risk of recurrent stroke in patients with a prior cryptogenic cerebral infarct. Although the absolute stroke reduction was small, these findings are clinically significant, given the young age of this patient population and the patients' lifetime risk of recurrent stroke. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Stroke incidence and mortality trends in US communities, 1987 to 2011.

PubMed

Koton, Silvia; Schneider, Andrea L C; Rosamond, Wayne D; Shahar, Eyal; Sang, Yingying; Gottesman, Rebecca F; Coresh, Josef

2014-07-16

Prior studies have shown decreases in stroke mortality over time, but data on validated stroke incidence and long-term trends by race are limited. To study trends in stroke incidence and subsequent mortality among black and white adults in the Atherosclerosis Risk in Communities (ARIC) cohort from 1987 to 2011. Prospective cohort study of 14,357 participants (282,097 person-years) free of stroke at baseline was facilitated in 4 different US communities. Participants were recruited for the purpose of studying all stroke hospitalizations and deaths and for collection of baseline information on cardiovascular risk factors (via interviews and physical examinations) in 1987-1989. Participants were followed up (via examinations, annual phone interviews, active surveillance of discharges from local hospitals, and linkage with the National Death Index) through December 31, 2011. The study physician reviewers adjudicated all possible strokes and classified them as definite or probable ischemic or hemorrhagic events. Trends in rates of first-ever stroke per 10 years of calendar time were estimated using Poisson regression incidence rate ratios (IRRs), with subsequent mortality analyzed using Cox proportional hazards regression models and hazard ratios (HRs) overall and by race, sex, and age divided at 65 years. Among 1051 (7%) participants with incident stroke, there were 929 with incident ischemic stroke and 140 with incident hemorrhagic stroke (18 participants had both during the study period). Crude incidence rates were 3.73 (95% CI, 3.51-3.96) per 1000 person-years for total stroke, 3.29 (95% CI, 3.08-3.50) per 1000 person-years for ischemic stroke, and 0.49 (95% CI, 0.41-0.57) per 1000 person-years for hemorrhagic stroke. Stroke incidence decreased over time in white and black participants (age-adjusted IRRs per 10-year period, 0.76 [95% CI, 0.66-0.87]; absolute decrease of 0.93 per 1000 person-years overall). The decrease in age-adjusted incidence was evident in participants age 65 years and older (age-adjusted IRR per 10-year period, 0.69 [95% CI, 0.59-0.81]; absolute decrease of 1.35 per 1000 person-years) but not evident in participants younger than 65 years (age-adjusted IRR per 10-year period, 0.97 [95% CI, 0.76-1.25]; absolute decrease of 0.09 per 1000 person-years) (P = .02 for interaction). The decrease in incidence was similar by sex. Of participants with incident stroke, 614 (58%) died through 2011. The mortality rate was higher for hemorrhagic stroke (68%) than for ischemic stroke (57%). Overall, mortality after stroke decreased over time (hazard ratio [HR], 0.80 [95% CI, 0.66-0.98]; absolute decrease of 8.09 per 100 strokes after 10 years [per 10-year period]). The decrease in mortality was mostly accounted for by the decrease at younger than age 65 years (HR, 0.65 [95% CI, 0.46-0.93]; absolute decrease of 14.19 per 100 strokes after 10 years [per 10-year period]), but was similar across race and sex. In a multicenter cohort of black and white adults in US communities, stroke incidence and mortality rates decreased from 1987 to 2011. The decreases varied across age groups, but were similar across sex and race, showing that improvements in stroke incidence and outcome continued to 2011.

[The consequences of stroke for the artist Lovis Corinth].

PubMed

Bäzner, H; Hennerici, M G

2006-09-01

The artist Lovis Corinth suffered a right-hemispheric stroke at the age of 53 years but only died 14 years later. The huge amount of work he produced after this life threatening disease allows detailed analysis of his post-stroke artwork in comparison to pre-stroke. When performing this analysis as a neurologist, an enormous diversity of subtle stroke sequelae can be discovered that are mostly explained by left-sided hemi-neglect. These findings clearly go far beyond pure psychological processes. Moreover, Corinth is a motivating example for disabled patients because he was able to produce great artwork after his stroke. He was struggling against a motor disability admittedly not severely affecting his artistic production, but also against severe neuropsychological deficits that did have clear consequences. Lovis Corinth left us the credo "True art means to use unreality". Taken together with the often cited phrase "Drawing means to leave out (details)", a clear-cut interpretation for neurologists can be derived from the understanding of right-hemisphere lesions and subsequent left-sided neglect.

A new theory of cryptogenic stroke and its relationship to patent foramen ovale; or, the puzzle of the missing extra risk.

PubMed

Eggers, Arnold E

2006-01-01

Cryptogenic stroke (or stroke of undetermined cause) is a common cause of stroke and is statistically associated with patent foramen ovale (PFO). The largest study of cryptogenic stroke is the Homma study, which is a sub-study of the WARSS trial; it produced the following data: cryptogenic stroke patients with and without PFO, when treated with either aspirin or warfarin, all had identical recurrence rates. This is puzzling because it seems as though there ought to have been some extra risk in one of the two groups under one of the two treatments. How could everything come out the same? A review of the epidemiology of cryptogenic stroke shows that, compared to patients with stroke of determined cause, cryptogenic stroke patients are a little younger and have lower doses of the usual risk factors (hypertension and diabetes mellitus) but more PFO. Cryptogenic strokes appear to be embolic strokes from an unknown source. A previously published article setting forth a hypothetical theory of stress-induced stroke was used to analyze these data. It is suggested that stress can induce episodic systemic platelet activation and hypercoagulability, which causes transient thrombus formation and subsequent embolization on both the arterial and venous sides of the circulation; the latter requires a PFO to cause a stroke (paradoxical embolism). The sum of these two mechanisms explains cryptogenic stroke. The PFO subset of cryptogenic stroke includes patients with both early and late stage disease who have an aggregate risk approximately equal to that of patients without PFO. Cryptogenic stroke is part of the disease of stress-induced cerebrovascular disease. Aspirin and warfarin have already been shown to be equally effective in secondary prevention of ischemic stroke.

A Functional Return-to-Play Progression After Exertional Heat Stroke in a High School Football Player.

PubMed

Lopez, Rebecca M; Tanner, Patrick; Irani, Sarah; Mularoni, P Patrick

2018-03-01

  To present a functional return-to-play (RTP) progression after exertional heat stroke (EHS) in a 17-year-old high school football defensive end (height = 185 cm, mass = 145.5 kg).   The patient had no pertinent medical history but moved to a warm climate several days before the EHS occurred. After completing an off-season conditioning test (14- × 110-yd [12.6- × 99.0-m] sprints) on a warm afternoon (temperature = approximately 34°C [93°F], relative humidity = 53%), the patient collapsed. An athletic trainer (AT) was called to the field, where he found the patient conscious but exhibiting central nervous system dysfunction. Emergency medical services were summoned and immediately transported the patient to the hospital.   Exertional heat stroke, heat exhaustion, exertional sickling, rhabdomyolysis, and cardiac arrhythmia.   The patient was immediately transported to a hospital, where his oral temperature was 39.6°C (103.3°F). He was transferred to a children's hospital and treated for rhabdomyolysis, transaminitis, and renal failure. He was hospitalized for 11 days. After a physician's clearance once the laboratory results normalized, an RTP progression was completed. The protocol began with light activity and progressed over 3 weeks to full football practice. During activity, an AT monitored the patient's gastrointestinal temperature, heart rate, rating of perceived exertion, fluid consumption, and sweat losses.   Documentation of RTP guidelines for young athletes is lacking. We used a protocol intended for the football setting to ensure the athlete was heat tolerant, had adequate physical fitness, and could safely RTP. Despite his EHS, he recovered fully, with no lasting effects, and successfully returned to compete in the final 5 games of the season.   Using a gradual RTP progression and close monitoring, a high school defensive end successfully returned to football practice and games after EHS. This case demonstrates the feasibility of implementing a safe RTP protocol after EHS and may serve as a guide to ATs working in the high school setting. This case also highlights the need for more research in this area.

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.

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.

State-changes in the swimmeret system: a neural circuit that drives locomotion

PubMed Central

Tschuluun, N.; Hall, W. M.; Mulloney, B.

2009-01-01

Summary The crayfish swimmeret system undergoes transitions between a silent state and an active state. In the silent state, no patterned firing occurs in swimmeret motor neurons. In the active state, bursts of spikes in power stroke motor neurons alternate periodically with bursts of spikes in return stroke motor neurons. In preparations of the isolated crayfish central nervous system (CNS), the temporal structures of motor patterns expressed in the active state are similar to those expressed by the intact animal. These transitions can occur spontaneously, in response to stimulation of command neurons, or in response to application of neuromodulators and transmitter analogues. We used single-electrode voltage clamp of power-stroke exciter and return-stroke exciter motor neurons to study changes in membrane currents during spontaneous transitions and during transitions caused by bath-application of carbachol or octopamine (OA). Spontaneous transitions from silence to activity were marked by the appearance of a standing inward current and periodic outward currents in both types of motor neurons. Bath-application of carbachol also led to the development of these currents and activation of the system. Using low Ca2+–high Mg2+ saline to block synaptic transmission, we found that the carbachol-induced inward current included a direct response by the motor neuron and an indirect component. Spontaneous transitions from activity to silence were marked by disappearance of the standing inward current and the periodic outward currents. Bath-application of OA led promptly to the disappearance of both currents, and silenced the system. OA also acted directly on both types of motor neurons to cause a hyperpolarizing outward current that would contribute to silencing the system. PMID:19880720

State-changes in the swimmeret system: a neural circuit that drives locomotion.

PubMed

Tschuluun, N; Hall, W M; Mulloney, B

2009-11-01

The crayfish swimmeret system undergoes transitions between a silent state and an active state. In the silent state, no patterned firing occurs in swimmeret motor neurons. In the active state, bursts of spikes in power stroke motor neurons alternate periodically with bursts of spikes in return stroke motor neurons. In preparations of the isolated crayfish central nervous system (CNS), the temporal structures of motor patterns expressed in the active state are similar to those expressed by the intact animal. These transitions can occur spontaneously, in response to stimulation of command neurons, or in response to application of neuromodulators and transmitter analogues. We used single-electrode voltage clamp of power-stroke exciter and return-stroke exciter motor neurons to study changes in membrane currents during spontaneous transitions and during transitions caused by bath-application of carbachol or octopamine (OA). Spontaneous transitions from silence to activity were marked by the appearance of a standing inward current and periodic outward currents in both types of motor neurons. Bath-application of carbachol also led to the development of these currents and activation of the system. Using low Ca(2+)-high Mg(2+) saline to block synaptic transmission, we found that the carbachol-induced inward current included a direct response by the motor neuron and an indirect component. Spontaneous transitions from activity to silence were marked by disappearance of the standing inward current and the periodic outward currents. Bath-application of OA led promptly to the disappearance of both currents, and silenced the system. OA also acted directly on both types of motor neurons to cause a hyperpolarizing outward current that would contribute to silencing the system.

From monitoring physiological functions to using psychological strategies. Nurses' view of caring for the aneurysmal subarachnoid haemorrhage patient.

PubMed

Hedlund, Mathilde; Ronne-Engstrom, Elisabeth; Ekselius, Lisa; Carlsson, Marianne

2008-02-01

The aims of this study were: (1) to describe nurses' views of the physical and supportive needs of patients who have suffered a subarachnoid haemorrhage (SAH), (2) to describe nurses' views of changes in social circumstances and (3) changes in the mental condition of patients after SAH. As patients with SAH are generally younger and predominantly female compared with other stroke groups they may have different needs of nursing support to facilitate adaptation. Caring for persons surviving stroke involves advanced nursing skills such as monitoring neurological functions in neurointensive care and providing physical care during rehabilitation. Explorative descriptive design. Semi-structured interviews were performed with 18 nurses in neurointensive and rehabilitation care. A qualitative latent content analysis was conducted. Nurses viewed patients' need for support as a process ranging from highly advanced technological care to 'softer' more emotional care. However, shortages in the communication between neurointesive and rehabilitation nurses regarding this support were acknowledged. Changes in social circumstances and mental conditions were viewed both as obstacles and advantages regarding return to everyday life. Nurses also viewed that the characteristics of the group with SAH was not particularly different from the group with other types of stroke. Support to patients with SAH is viewed as a process carried out by nurses at neurointensive care units and rehabilitation units. Shortages in communication, regarding this support, were acknowledged. Obstacles and advantages with respect to returning to everyday life could apply to any stroke group, which could make it more difficult for nurses to detect the specific needs of patients with SAH. The communication between neurointensive nurses and rehabilitation nurses regarding support to patients with SAH is not satisfactory. Occasionally the specific needs of patients with SAH are not recognized.

Development of a prognostic scale for severely hemiplegic stroke patients in a rehabilitation hospital.

PubMed

Hirano, Yoshitake; Nitta, Osamu; Hayashi, Takeshi; Takahashi, Hidetoshi; Miyazaki, Yasuhiro; Kigawa, Hiroshi

2017-07-01

For patients with severe hemiplegia in a rehabilitation hospital, early prediction of the functional prognosis and outcomes is challenging. The purpose of this study was to create and verify a prognostic scale in severely hemiplegic stroke patients and allowing for prediction of (1) the ability to walk at the time of hospital discharge, (2) the ability to carry out activities of daily living (ADL), and (3) feasibility of home discharge. The study was conducted on 80 severely hemiplegic stroke patients. A prognostic scale was created as an analysis method using the following items: mini-mental state examination (MMSE) at the time of admission, modified NIH stroke scale (m-NIHSS); trunk control test (TCT); and the ratio of the knee extensor strength on the non-paralyzed side to the body weight (KES/BW-US). We verified the reliability and validity of this scale. We established a prognostic scale using the MMSE, m-NIHSS, TCT, and KES/BW-US. A score of 56.8 or higher on the prognostic scale suggested that the patient would be able to walk and that assistance with ADL would be unnecessary at the time of hospital discharge. In addition, a score of 41.3 points indicated that the patient's return home was feasible. The reliability and the results were in good agreement. These findings showed that the ability or inability to walk was predictable in 85%, the need of assistance with ADL in 82.5%, and the feasibility of home return in 76.3% of cases. At the time of admission, four evaluation items permitted the prediction of three outcomes at time of discharge. Our formula predicts three outcomes with an accuracy of more than 76%. Copyright © 2017 Elsevier B.V. All rights reserved.

Return to Basketball and Soccer After Anterior Cruciate Ligament Reconstruction in Competitive School-Aged Athletes

PubMed Central

Shelbourne, K. Donald; Sullivan, A. Nichole; Bohard, Katie; Gray, Tinker; Urch, Scott E.

2009-01-01

Background: Little is known about the return to sports after anterior cruciate ligament reconstruction and whether sex differences exist regarding the level and timing at which athletes return. Hypotheses: Compared to school-aged girls, boys return to full sports earlier and at a higher frequency after surgery (1). Athletes who return to sports earlier will not have a higher incidence of subsequent injury to either knee after surgery (2). Study Design: Cohort. Methods: The patient population comprised 413 consecutive school-aged athletes who were injured while competing in basketball or soccer. Patients were enrolled prospectively, and activity levels were obtained through follow-up visits, surveys, phone calls, and e-mail. Results: Follow-up was obtained for 402 patients (basketball: 58 boys, 242 girls; soccer: 25 boys, 77 girls). Eighty-seven percent of girls and boys returned to high school basketball after surgery: the mean time to return to full participation in basketball was 5.2 ± 2.1 months for girls and 5.3 ± 2.2 months for boys (P = .92). Similarly, 93% of girls and 80% of boys returned to compete in high school soccer after surgery (P = .13); the mean time to return to full participation in soccer was 5.1 ± 1.9 months for girls and 5.1 ± 2.0 for boys (P = 1.00). About 20% of athletes went on to compete in their sport in college. The time of return to sports was not a statistically significant factor for the incidence of subsequent anterior cruciate ligament injury. Conclusion: Of 402 athletes competing in basketball and soccer, women and men returned at the same rate and same level of sport after surgery. Athletes who returned to sports at earlier times after surgery did not have a higher incidence of subsequent anterior cruciate ligament injury than patients who returned at later times. PMID:23015878

Staying married after stroke: a constructivist grounded theory qualitative study.

PubMed

Anderson, Sharon; Keating, Norah C; Wilson, Donna M

2017-10-01

Marriages are one of the most powerful predictors of health and longevity, yet research in stroke has focused separately on survivors' experience of impairments and how spouses deal with caregiving. The purpose of this constructivist grounded theory study was to understand the key themes related to reconstruction or breakdown of marriages after stroke. In semi-structured interviews, 18 couples in long-term marriages discussed how their marriages were reconstructed or broke down after one member of the couple returned home after being hospitalized for a stroke. Constant comparison methods were used to compare the experiences of 12 couples in which both partners indicated their relationship was going well with 6 couples who either separated or remained in parallel marriages. Analysis revealed an overarching process of reconstructing compatible role-identities and three themes related to the reconstruction or breakdown of the marital identity: feeling overwhelmed, resolving conflict, and perceiving value in the marriage. Our findings highlight that marriages are contexts in which survivors and spouses can recalibrate their role-identities. Marriage relationships are not peripheral to survivors' and spouses' outcomes after stroke; rather, marriage is fundamental to the management of impairments and to the well-being of the couple.

Combination of blood flow asymmetry in the cerebral and cerebellar hemispheres on brain perfusion SPECT predicts 5-year outcome in patients with symptomatic unilateral major cerebral artery occlusion.

PubMed

Nomura, Jun-ichi; Ogasawara, Kuniaki; Saito, Hideo; Terasaki, Kazunori; Matsumoto, Yoshiyasu; Takahashi, Yoshihiro; Ogasawara, Yasushi; Saura, Hiroaki; Yoshida, Koji; Sato, Yuiko; Kubo, Yoshitaka; Ogawa, Akira

2014-03-01

Misery perfusion increases the risk of stroke recurrence in patients with symptomatic major cerebral artery occlusion. The ratio of brain perfusion contralateral-to-affected asymmetry in the cerebellar hemisphere to brain perfusion affected-to-contralateral asymmetry in the cerebral hemisphere (CblPR/CbrPR) indicates affected-to-contralateral asymmetry of oxygen extraction fraction (OEF) in the cerebral hemisphere. The purpose of the present study was to determine whether the CblPR/CbrPR on brain perfusion single-photon emission computed tomography (SPECT) predicts 5-year outcomes in patients with symptomatic unilateral occlusion of the middle cerebral artery (MCA) or internal carotid artery (ICA). Brain perfusion was assessed using N-isopropyl-p-[123I]-iodoamphetamine (123I-IMP) SPECT in 70 patients. A region of interest (ROI) was manually placed in the bilateral MCA territories and in the bilateral cerebellar hemispheres, and the CblPR/CbrPR was calculated. All patients were prospectively followed for 5 years. The primary end points were stroke recurrence or death. A total of 17 patients exhibited the primary end points, 11 of whom experienced subsequent ipsilateral strokes. Multivariate analysis revealed that only high CblPR/CbrPR was significantly associated with the development of the primary end point or subsequent ipsilateral strokes (95% confidential limits [CIs], 1.130-3.145; P  =  0.0114 or 95% CIs, 2.558-5.140; P  =  0.0045, respectively). The CblPR/CbrPR provided 65% (11/17) or 91% (10/11) sensitivity and 88% (47/53) or 88% (52/59) specificity in predicting the primary end point or subsequent ipsilateral strokes, respectively. The CblPR/CbrPR on brain perfusion SPECT predicts 5-year outcomes in patients with symptomatic unilateral occlusion of the MCA or ICA.

Internal Carotid Artery Web as the Cause of Recurrent Cryptogenic Ischemic Stroke.

PubMed

Antigüedad-Muñoz, Jon; de la Riva, Patricia; Arenaza Choperena, Gorka; Muñoz Lopetegi, Amaia; Andrés Marín, Naiara; Fernández-Eulate, Gorka; Moreno Valladares, Manuel; Martínez Zabaleta, Maite

2018-05-01

Carotid artery web is considered an exceptional cause of recurrent ischemic strokes in the affected arterial territory. The underlying pathology proposed for this entity is an atypical fibromuscular dysplasia. We present the case of a 43-year-old woman with no cardiovascular risk factors who had experienced 2 cryptogenic ischemic strokes in the same arterial territory within an 11-month period. Although all diagnostic tests initially yielded normal results, detailed analysis of the computed tomography angiography images revealed a carotid web; catheter angiography subsequently confirmed the diagnosis. Carotid surgery was performed, since which time the patient has remained completely asymptomatic. The histological finding of intimal hyperplasia is consistent with previously reported cases of carotid artery web. Carotid artery web is an infrequent cause of stroke, and this diagnosis requires a high level of suspicion plus a detailed analysis of vascular imaging studies. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Validity of self-reported stroke in elderly African Americans, Caribbean Hispanics, and Whites.

PubMed

Reitz, Christiane; Schupf, Nicole; Luchsinger, José A; Brickman, Adam M; Manly, Jennifer J; Andrews, Howard; Tang, Ming X; DeCarli, Charles; Brown, Truman R; Mayeux, Richard

2009-07-01

The validity of a self-reported stroke remains inconclusive. To validate the diagnosis of self-reported stroke using stroke identified by magnetic resonance imaging (MRI) as the standard. Community-based cohort study of nondemented, ethnically diverse elderly persons in northern Manhattan. High-resolution quantitative MRIs were acquired for 717 participants without dementia. Sensitivity and specificity of stroke by self-report were examined using cross-sectional analyses and the chi(2) test. Putative relationships between factors potentially influencing the reporting of stroke, including memory performance, cognitive function, and vascular risk factors, were assessed using logistic regression models. Subsequently, all analyses were repeated, stratified by age, sex, ethnic group, and level of education. In analyses of the whole sample, sensitivity of stroke self-report for a diagnosis of stroke on MRI was 32.4%, and specificity was 78.9%. In analyses stratified by median age (80.1 years), the validity between reported stroke and detection of stroke on MRI was significantly better in the younger than the older age group (for all vascular territories: sensitivity and specificity, 36.7% and 81.3% vs 27.6% and 26.2%; P = .02). Impaired memory, cognitive skills, or language ability and the presence of hypertension or myocardial infarction were associated with higher rates of false-negative results. Using brain MRI as the standard, specificity and sensitivity of stroke self-report are low. Accuracy of self-report is influenced by age, presence of vascular disease, and cognitive function. In stroke research, sensitive neuroimaging techniques rather than stroke self-report should be used to determine stroke history.

Comparison of Medicare Claims vs. Physician Adjudication for Identifying Stroke Outcomes in the Women’s Health Initiative

PubMed Central

Lakshminarayan, Kamakshi; Larson, Joseph C.; Virnig, Beth; Fuller, Candace; Allen, Norrina Bai; Limacher, Marian; Winkelmayer, Wolfgang C.; Safford, Monika M.; Burwen, Dale R.

2014-01-01

Background and Purpose Many studies use medical record review for ascertaining outcomes. One large, longitudinal study, the Women’s Health Initiative (WHI) ascertains strokes using participant self-report and subsequent physician review of medical records. This is resource-intensive. Herein, we assess whether Medicare data can reliably assess stroke events in the WHI. Methods Subjects were WHI participants with fee-for-service Medicare. Four stroke definitions were created for Medicare data using discharge diagnoses in hospitalization claims. Definition 1: stroke codes in any position; Definition 2: primary position stroke codes; Definitions 3 & 4: hemorrhagic and ischemic stroke codes respectively. WHI data were randomly split into training (50%) and test sets. A concordance matrix was used to examine agreement between WHI and Medicare stroke diagnosis. A WHI stroke and a Medicare stroke were considered a match if they occurred within +/− 7 days of each other. Refined analyses excluded Medicare events where medical records were unavailable for comparison. Results Training data (n=24,428): There were 577 WHI strokes and 557 Medicare strokes using definition 1. Of these, 478 were a match. Algorithm performance: Specificity 99.7%; Negative Predictive Value 99.7%; Sensitivity 82.8%; Positive Predictive Value 85.8%; kappa 0.84. Performance was similar for test data. While specificity and negative predictive value exceeded 99%, sensitivity ranged from 75 to 88% and positive predictive value ranged from 80 to 90% across stroke definitions. Conclusion Medicare data appear useful for population-based stroke research; however the performance characteristics depend on the definition selected. PMID:24525955

Cryostimulation improves recovery from oropharyngeal dysphagia after stroke

PubMed Central

Zart, Patrícia; Levy, Deborah Salle; Bolzan, Geovana de Paula; Mancopes, Renata; da Silva, Ana Maria Toniolo

2013-01-01

Summary Introduction: Stroke is considered one of the most frequent neurological causes of oropharyngeal dysphagia. Aim: To determine the effect of cryostimulation on oropharyngeal sensitivity and, subsequently, on the swallowing reaction and premature escape of food in patients with neurogenic dysphagia after stroke. Methods: Clinical and experimental study. The study enrolled 7 adult subjects, 6 men and 1 woman ranging from 28 to 64 years of age, with a diagnosis of stroke and current oropharyngeal dysphagia without any other underlying disease. The selected subjects underwent speech-language pathology evaluation and videofluoroscopic assessment of the dysphagia. The subjects were then treated with cryostimulation consisting of 10 applications to each structure (anterior faucial pillar, posterior oropharyngeal wall, soft palate, and back tongue) 3 times a day (for a total of 30 daily applications per structure) for 4 consecutive days. The patients were then re-evaluated based on the same criteria. The pre- and post-cryostimulation results of the clinical and videofluoroscopic evaluations were analyzed descriptively and statistically using Student's t-test and Fisher's exact test. Results: Cryostimulation had beneficial effects on oropharyngeal sensitivity in 6 of the 7 subjects. There was also a significant improvement in swallowing and in the premature escape in six subjects. Conclusion: Cryostimulation increased sensitivity and subsequently improved the swallowing reaction and premature escape of food in patients with neurogenic dysphagia after stroke. These effects were evident by both speech-language pathology and videofluoroscopic evaluation. PMID:25991991

Current status of stroke epidemiology in Greece: a panorama.

PubMed

Vasiliadis, Angelo V; Zikić, Milorad

2014-01-01

Although strokes have been documented since about 3 millennia, they remain today as one of the leading causes of mortality, as well as of subsequent serious long-term physical and mental morbidity, among patients in many different countries all over the world. Greece presents an increase in mortality rates according to World Health Organization, and this fact underlines the need for early diagnosis and treatment, as well as, the need to implement effective prevention strategies for strokes. This review makes an effort to describe the current status of stroke epidemiological features, as well as to present the risk factors prevalent in Greece. The incidence rate is 261-319/100,000 based on the recent population based registry. Stroke appears to be more prevalent in men than in women, and the mean age of stroke onset in Greece is at 70 years of age. Hypertension, atrial fibrillation, dyslipidaemia and diabetes mellitus are the major risk factors of stroke in the Greek population, while smoking is the most commonly documented modifiable risk factor in young adults with ischemic stroke. Similar to other parts of the world, ischemic stroke is the most common stroke type. The 28-day case fatality rate for men and women was 26.5%. The mean in-hospital cost per stroke patient was 3624.9 € and the mean rehabilitation cost of outpatients with stroke was 5553.3 €, while the cost proportion of hemorrhagic stroke is higher when compared to ischemic stroke. Stroke is a devastating condition with recognized challenges in identifying effective prevention programs. In Greece, limited data exists regarding the epidemiology of strokes. As a result, the need to conduct new studies and researches across the country is well documented. Copyright © 2014 Polish Neurological Society. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

The network of Shanghai Stroke Service System (4S): A public health-care web-based database using automatic extraction of electronic medical records.

PubMed

Dong, Yi; Fang, Kun; Wang, Xin; Chen, Shengdi; Liu, Xueyuan; Zhao, Yuwu; Guan, Yangtai; Cai, Dingfang; Li, Gang; Liu, Jianmin; Liu, Jianren; Zhuang, Jianhua; Wang, Panshi; Chen, Xin; Shen, Haipeng; Wang, David Z; Xian, Ying; Feng, Wuwei; Campbell, Bruce Cv; Parsons, Mark; Dong, Qiang

2018-07-01

Background Several stroke outcome and quality control projects have demonstrated the success in stroke care quality improvement through structured process. However, Chinese health-care systems are challenged with its overwhelming numbers of patients, limited resources, and large regional disparities. Aim To improve quality of stroke care to address regional disparities through process improvement. Method and design The Shanghai Stroke Service System (4S) is established as a regional network for stroke care quality improvement in the Shanghai metropolitan area. The 4S registry uses a web-based database that automatically extracts data from structured electronic medical records. Site-specific education and training program will be designed and administrated according to their baseline characteristics. Both acute reperfusion therapies including thrombectomy and thrombolysis in the acute phase and subsequent care were measured and monitored with feedback. Primary outcome is to evaluate the differences in quality metrics between baseline characteristics (including rate of thrombolysis in acute stroke and key performance indicators in secondary prevention) and post-intervention. Conclusions The 4S system is a regional stroke network that monitors the ongoing stroke care quality in Shanghai. This project will provide the opportunity to evaluate the spectrum of acute stroke care and design quality improvement processes for better stroke care. A regional stroke network model for quality improvement will be explored and might be expanded to other large cities in China. Clinical Trial Registration-URL http://www.clinicaltrials.gov . Unique identifier: NCT02735226.

Trampolines, children, and strokes.

PubMed

Wechsler, B; Kim, H; Hunter, J

2001-08-01

Strokes in children related to sports injuries are rare, but pediatric trampoline injuries are dramatically increasing. Minor trauma to the vulnerable extracranial vertebral arteries as they travel superficially through the dorsum of the neck can begin a cascade of events that results in arterial dissection, thrombus formation, and embolization with cerebral infarction. We present the case of an 11-yr-old boy who developed left vertebral artery dissection subsequent to a trampoline injury.

Small Negative Cloud-to-Ground Lightning Reports at the KSC-ER

NASA Technical Reports Server (NTRS)

Wilson, Jennifer G.; Cummins, Kenneth L.; Krider, E. Philip

2009-01-01

'1he NASA Kennedy Space Center (KSC) and Air Force Eastern Range (ER) use data from two cloud-to-ground (CG) lightning detection networks, the CGLSS and the NLDN, and a volumetric lightning mapping array, LDAR, to monitor and characterize lightning that is potentially hazardous to ground or launch operations. Data obtained from these systems during June-August 2006 have been examined to check the classification of small, negative CGLSS reports that have an estimated peak current, [I(sup p)] less than 7 kA, and to determine the smallest values of I(sup p), that are produced by first strokes, by subsequent strokes that create a new ground contact (NGC), and by subsequent strokes that remain in a pre-existing channel (PEC). The results show that within 20 km of the KSC-ER, 21% of the low-amplitude negative CGLSS reports were produced by first strokes, with a minimum I(sup p) of-2.9 kA; 31% were by NGCs, with a minimum I(sup p) of-2.0 kA; and 14% were by PECs, with a minimum I(sup p) of -2.2 kA. The remaining 34% were produced by cloud pulses or lightning events that we were not able to classify.

Lightning Channels of Cloud-to-Ground Flashes Neutralizing Multiple Charge Regions Inside Winter Thunderclouds

NASA Astrophysics Data System (ADS)

Akita, Manabu; Yoshida, Satoru; Nakamura, Yoshitaka; Morimoto, Takeshi; Ushio, Tomoo; Kawasaki, Zen-Ichiro; Wang, Daohong

Lightning Research Group of Osaka University (LRG-OU) has been developing and improving the VHF broadband digital interferometer (DITF) for thunderstorm observations. It enables us to locate the impulsive VHF radiation sources caused by lightning discharges with extremely high resolutions. As a result of the VHF observations during the 2007-2008 winter season in the Japan Sea coastal area, cloud-to-ground (CG) flashes that neutralize multiple charge regions inside thunderclouds are visualized by the VHF broadband DITF. The first flash is the positive CG flash that neutralizes multiple positive charge regions in a flash. The second flash is the bipolar lightning flash that neutralizes both positive and negative charge inside thunderclouds. In the case of bipolar lightning flashes, some tens millisecond after the return strokes, the subsequent negative breakdowns initiate from the proximities of the initiation points of the preceding negative stepped leaders. It was also found that the altitudes of negative charge regions are lower than 2km. The bipolar lightning flashes observed in this campaign neutralize positive charge after lowering the negative charge to the ground.

Stroke survivors' levels of community reintegration, quality of life, satisfaction with the physiotherapy services and the level of caregiver strain at community health centres within the Johannesburg area.

PubMed

Kusambiza-Kiingi, Adrian; Maleka, Douglas; Ntsiea, Veronica

2017-01-01

Stroke survivors are discharged home before they are functionally independent and return home with activity limitations that would not be manageable without a caregiver. To determine stroke survivors' levels of community reintegration, quality of life (QOL), satisfaction with the physiotherapy services and the level of caregiver strain at community health centres within the Johannesburg area. This was a cross-sectional study using the following outcome measures: Maleka Stroke Community Reintegration Measure, Stroke-specific quality of life scale, Caregiver strain index and Physical therapy patient satisfaction questionnaire. A total of 108 stroke survivors and 45 caregivers participated in this study. The average age of the stroke survivors was 54 years (standard deviation = 12.73) and 58% ( n = 62) had moderate to full community reintegration. They were happy with physiotherapy services but not with parking availability and cost of services. The QOL was poor with the lowest scores for energy and highest scores for vision and language domains. Twenty five (55%) caregivers were strained. A positive correlation was found between community reintegration and satisfaction with services ( r = 0.27, p < 0.0001) and QOL ( r = 0.51, p < 0.0001). A negative correlation was found between community reintegration and caregiver strain ( r = -0.37, p < 0.0001). Most stroke survivors are reintegrated into their communities except in the areas of work and education and have poor QOL and most of their caregivers are strained; however, they are satisfied with physiotherapy services.

Stroke survivors’ levels of community reintegration, quality of life, satisfaction with the physiotherapy services and the level of caregiver strain at community health centres within the Johannesburg area

PubMed Central

Kusambiza-Kiingi, Adrian; Maleka, Douglas

2017-01-01

Background Stroke survivors are discharged home before they are functionally independent and return home with activity limitations that would not be manageable without a caregiver. Aim To determine stroke survivors’ levels of community reintegration, quality of life (QOL), satisfaction with the physiotherapy services and the level of caregiver strain at community health centres within the Johannesburg area. Method This was a cross-sectional study using the following outcome measures: Maleka Stroke Community Reintegration Measure, Stroke-specific quality of life scale, Caregiver strain index and Physical therapy patient satisfaction questionnaire. Results A total of 108 stroke survivors and 45 caregivers participated in this study. The average age of the stroke survivors was 54 years (standard deviation = 12.73) and 58% (n = 62) had moderate to full community reintegration. They were happy with physiotherapy services but not with parking availability and cost of services. The QOL was poor with the lowest scores for energy and highest scores for vision and language domains. Twenty five (55%) caregivers were strained. A positive correlation was found between community reintegration and satisfaction with services (r = 0.27, p < 0.0001) and QOL (r = 0.51, p < 0.0001). A negative correlation was found between community reintegration and caregiver strain (r = -0.37, p < 0.0001). Conclusion Most stroke survivors are reintegrated into their communities except in the areas of work and education and have poor QOL and most of their caregivers are strained; however, they are satisfied with physiotherapy services. PMID:28730068

A retrospective cohort study to investigate fatigue, psychological or cognitive impairment after TIA: protocol paper.

PubMed

Moran, Grace M; Calvert, Melanie; Feltham, Max G; Ryan, Ronan; Marshall, Tom

2015-05-03

Transient ischaemic attack (TIA) is defined by short-lasting, stroke-like symptoms, and is recognised as a medical emergency. Symptoms are assumed to completely resolve, and treatment is focused on secondary stroke/TIA prevention. However, evidence suggests that patients with TIA may experience ongoing residual impairments, which they do not receive therapy for as standard practice. TIA-induced sequelae could impact on patients' quality of life and ability to return to work or social activities. We aim to investigate whether TIA is associated with subsequent consultation for fatigue, psychological or cognitive impairment in primary care. A retrospective open cohort study of patients with first-ever TIA and matched controls. Relevant data will be extracted from The Health Improvement Network (THIN) database, an anonymised primary care database which includes data for over 12 million patients and covers approximately 6% of the UK population. Outcomes will be the first consultation for fatigue, anxiety, depression, post-traumatic stress disorder or cognitive impairment. Principal analysis will use Kaplan-Meier survivor functions to estimate time to first consultation, with log-rank tests to compare TIA and control patients. Cox proportional hazard models will predict the effect of demographic and patient characteristics on time to first consultation. Approval was granted by a THIN Scientific Review Committee (ref: 14-008). The study's findings will be published in a peer-reviewed journal and disseminated at national and international conferences and through social media. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

The long-term nutritional status in stroke patients and its predictive factors.

PubMed

Paquereau, Julie; Allart, Etienne; Romon, Monique; Rousseaux, Marc

2014-07-01

Malnutrition is common in the first few months after stroke and contributes to a poor overall outcome. We analyzed long-term weight changes and their predictive factors. A total of 71 first-ever stroke patients were included in the study and examined (1) their weight on admission to the acute stroke unit (usual weight [UW]), on admission to the rehabilitation unit, on discharge from the rehabilitation unit, and then 1 year or more after the stroke (median time: 2.5 years), (2) the presence of malnutrition after stroke, and (3) possible predictive factors, namely, sociodemographic factors, clinical characteristics (concerning the stroke, the patient's current neurologic status and the presence of diabetes mellitus and depression), and the present nutritional state (including eating difficulties, anorexia, and changes in food intake and food preferences). Body weight fell (4.0 kg) during the patients' stay in the stroke unit, increased moderately in the rehabilitation unit (2.0 kg), and returned to the UW by the long-term measurement. However, at the last observation, 40.1% of the patients weighed markedly less than their UW, 38.0% weighed markedly more, and 21.1% were relatively stable. Predictors of weight change were a change in preferences for sweet food products and a change in food intake. Malnutrition was frequent (47.9%) and associated with reduced food intake, residence in an institution, and diabetes mellitus. Malnutrition was highly prevalent, with an important role of change in food intake and food preferences, which could result from brain lesions and specific regimens. Living in an institution needs consideration, as its negative effects can be prevented. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

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.

Awareness of Stroke Risk after TIA in Swiss General Practitioners and Hospital Physicians.

PubMed

Streit, Sven; Baumann, Philippe; Barth, Jürgen; Mattle, Heinrich P; Arnold, Marcel; Bassetti, Claudio L; Meli, Damian N; Fischer, Urs

2015-01-01

Transient ischemic attacks (TIA) are stroke warning signs and emergency situations, and, if immediately investigated, doctors can intervene to prevent strokes. Nevertheless, many patients delay going to the doctor, and doctors might delay urgently needed investigations and preventative treatments. We set out to determine how much general practitioners (GPs) and hospital physicians (HPs) knew about stroke risk after TIA, and to measure their referral rates. We used a structured questionnaire to ask GPs and HPs in the catchment area of the University Hospital of Bern to estimate a patient's risk of stroke after TIA. We also assessed their referral behavior. We then statistically analysed their reasons for deciding not to immediately refer patients. Of the 1545 physicians, 40% (614) returned the survey. Of these, 75% (457) overestimated stroke risk within 24 hours, and 40% (245) overestimated risk within 3 months after TIA. Only 9% (53) underestimated stroke risk within 24 hours and 26% (158) underestimated risk within 3 months; 78% (473) of physicians overestimated the amount that carotid endarterectomy reduces stroke risk; 93% (543) would rigorously investigate the cause of a TIA, but only 38% (229) would refer TIA patients for urgent investigations "very often". Physicians most commonly gave these reasons for not making emergency referrals: patient's advanced age; patient's preference; patient was multimorbid; and, patient needed long-term care. Although physicians overestimate stroke risk after TIA, their rate of emergency referral is modest, mainly because they tend not to refer multimorbid and elderly patients at the appropriate rate. Since old and frail patients benefit from urgent investigations and treatment after TIA as much as younger patients, future educational campaigns should focus on the importance of emergency evaluations for all TIA patients.

Subsequent-year recaptures at winter sites in three species of shrubland sparrows (Emberizidae)

USGS Publications Warehouse

Knick, Steven T.; Leu, Matthias; Hanser, Steven E.

2017-01-01

The tendency by individual birds to return to winter sites in subsequent years can be important in assessing the potential influence of habitat changes during the nonbreeding period. We recaptured five Brewer's (Spizella breweri), seven sagebrush (Artemisiospiza nevadensis), and three black-throated (Amphispiza bilineata) sparrows from 1–3 subsequent years at the same winter location following their initial capture. Two Brewer's and one sagebrush sparrow returned to the same winter location at least 4 years after their initial capture. Levels of feather deuterium indicated that birds captured together on winter sites had different breeding ranges. Although individuals of these species returned to specific sites used in previous years, the low recapture rate suggests that wintering individuals may use an itinerant strategy adapted to seasonal food resources.

'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.

Mobile tablet-based therapies following stroke: A systematic scoping review of administrative methods and patient experiences

PubMed Central

Ramsay, Tim; Johnson, Dylan; Dowlatshahi, Dar

2018-01-01

Background and purpose Stroke survivors are often left with deficits requiring rehabilitation to recover function and yet, many are unable to access rehabilitative therapies. Mobile tablet-based therapies (MTBTs) may be a resource-efficient means of improving access to timely rehabilitation. It is unclear what MTBTs have been attempted following stroke, how they were administered, and how patients experienced the therapies. The review summarizes studies of MTBTs following stroke in terms of administrative methods and patient experiences to inform treatment feasibility. Methods Articles were eligible if they reported the results of an MTBT attempted with stroke participants. Six research databases were searched along with grey literature sources, trial registries, and article references. Intervention administration details and patient experiences were summarized. Results The search returned 903 articles of which 23 were eligible for inclusion. Most studies were small, observational, and enrolled chronic stroke patients. Interventions commonly targeted communication, cognition, or fine-motor skills. Therapies tended to be personalized based on patient deficits using commercially available applications. The complexity of therapy instructions, fine-motor requirements, and unreliability of internet or cellular connections were identified as common barriers to tablet-based care. Conclusions Stroke patients responded positively to MTBTs in both the inpatient and home settings. However, some support from therapists or caregivers may be required for patients to overcome barriers to care. Feasibility studies should continue to identify the administrative methods that minimize barriers to care and maximize patient adherence to prescribed therapy regiments. PMID:29360872

Quercetin protects against heat stroke-induced myocardial injury in male rats: Antioxidative and antiinflammatory mechanisms.

PubMed

Lin, Xiaojing; Lin, Cheng-Hsien; Zhao, Tingbao; Zuo, Dan; Ye, Zhujun; Liu, Lin; Lin, Mao-Tsun

2017-03-01

Heat stroke is characterized by hyperthermia, systemic inflammation, and multiple organ failure including arterial hypotension. This definition can be fulfilled by a rat model of heat stroke used in the present study. Anesthetized animals were exposed to heat exposure (43 °C for 70 min) and then returned to room temperature (26 °C) for recovery. One hour before heat exposure, an intraperitoneal dose of quercetin (30 mg/kg) or vehicle (normal saline 1 ml/kg) was administered to the experimental groups of rats. Additional injection was administered immediately after the onset of heat stroke. Immediately after the onset of heat stroke. Vehicle-treated rats displayed (i) hyperthermia; (ii) suppressed left ventricular function; (iii) decreased contents of cardiac total antioxiant capacity (e.g., superoxide dismutase, glutathione peroxidase, catalase); (iv) increased contents of cardiac oxidative capacity malondialdehyde and thiobarbituric acid reactive substances; (v) increased cardiac levels of pro-inflammatory cytokines tumor necrosis factor-α and interleukin-6; and (vi) decreased cardiac levels of an anti-inflammatory cytokine interleukin 10. Histopathologic and survival observation provided supportive evidence for biochemical analyses. These heat stroke reactions all can be significantly attenuated by quercetin therapy. Our data suggest that quercetin therapy might improve outcomes of heat stroke in rats by attenuating excessive hyperthermia as well as myocardial injury. The protective effects of quercetin could be attributed to anti-lipid peroxidative, anti-oxidant, and anti-inflammatory properties. Copyright © 2017 Elsevier B.V. All rights reserved.

Antihypertensive treatment and stroke prevention: are angiotensin receptor blockers superior to other antihypertensive agents?

PubMed

Armario, Pedro; de la Sierra, Alejandro

2009-06-01

Stroke remains a common vascular event with high mortality and morbidity. After heart disease, stroke is the second leading cause of death worldwide in adult persons. Silent or subclinical stroke is likely to occur with even greater frequency than clinical stroke and increases the risk of subsequent cerebrovascular events. Hypertension is by far the single most important controllable risk factor for stroke. The relationship between blood pressure (BP) and stroke mortality is strong, linear, and continuous in subjects with levels of BP higher than 115/75 mm Hg. Blood pressure reduction by antihypertensive treatment is clearly efficacious in the prevention of stroke (both primary and secondary). Although meta-analyses suggest that BP reduction, per se, is the most important determinant for stroke risk reduction, the question is if specific classes of antihypertensive drugs offer special protection against stroke is still controversial. Some studies have suggested that angiotensin receptors blockers (ARBs) appear to offer additional protection against stroke. This has been hypothesized in studies in hypertensives, such as LIFE and SCOPE, and especially in the only comparative trial focused on secondary stroke prevention. In the MOSES trial, the comparison of eprosartan versus nitrendipine in patients with a previous stroke resulted, despite a similar BP reduction, in a significant reduction in the primary composite endpoint of total mortality plus cardiovascular and cerebrovascular events, including recurrent events. These results may suggest a blood pressure-independent effect of ARBs, which can be mediated through several mechanisms, including their ability to counteract other markers of target organ damage, but also through a direct neuroprotective effect.

The Importance of Patient Involvement in Stroke Rehabilitation

PubMed Central

2016-01-01

Objective To investigate the perceived needs for health services by persons with stroke within the first year after rehabilitation, and associations between perceived impact of stroke, involvement in decisions regarding care/treatment, and having health services needs met. Method Data was collected, through a mail survey, from patients with stroke who were admitted to a university hospital in 2012 and had received rehabilitation after discharge from the stroke unit. The rehabilitation lasted an average of 2 to 4.6 months. The Stroke Survivor Needs Survey Questionnaire was used to assess the participants' perceptions of involvement in decisions on care or treatment and needs for health services in 11 problem areas: mobility, falls, incontinence, pain, fatigue, emotion, concentration, memory, speaking, reading, and sight. The perceived impact of stroke in eight areas was assessed using the Stroke Impact Scale (SIS) 3.0. Eleven logistic regression models were created to explore associations between having health services needs met in each problem area respectively (dependent variable) and the independent variables. In all models the independent variables were: age, sex, SIS domain corresponding to the dependent variable, or stroke severity in cases when no corresponding SIS domain was identified, and involvement in decisions on care and treatment. Results The 63 participants who returned the questionnaires had a mean age of 72 years, 33 were male and 30 were female. Eighty percent had suffered a mild stroke. The number of participants who reported problems varied between 51 (80%, mobility) and 24 (38%, sight). Involvement in decisions on care and treatment was found to be associated with having health services needs met in six problem areas: falls, fatigue, emotion, memory, speaking, and reading. Conclusions The results highlight the importance of involving patients in making decisions on stroke rehabilitation, as it appears to be associated with meeting their health services needs. PMID:27285997

The effectiveness of culturally tailored video narratives on medication understanding and use self-efficacy among stroke patients: A randomized controlled trial study protocol.

PubMed

Appalasamy, Jamuna Rani; Tha, Kyi Kyi; Quek, Kia Fatt; Ramaiah, Siva Seeta; Joseph, Joyce Pauline; Md Zain, Anuar Zaini

2018-06-01

A substantial number of the world's population appears to end with moderate to severe long-term disability after stroke. Persistent uncontrolled stroke risk factor leads to unpredicted recurrent stroke event. The increasing prevalence of stroke across ages in Malaysia has led to the adaptation of medication therapy adherence clinic (MTAC) framework. The stroke care unit has limited patient education resources especially for patients with medication understanding and use self-efficacy. Nevertheless, only a handful of studies have probed into the effectiveness of video narrative at stroke care centers. This is a behavioral randomized controlled trial of patient education intervention with video narratives for patients with stroke lacking medication understanding and use self-efficacy. The study will recruit up to 200 eligible stroke patients at the neurology tertiary outpatient clinic, whereby they will be requested to return for follow-up approximately 3 months once for up to 12 months. Consenting patients will be randomized to either standard patient education care or intervention with video narratives. The researchers will ensure control of potential confounding factors, as well as unbiased treatment review with prescribed medications only obtained onsite. The primary analysis outcomes will reflect the variances in medication understanding and use self-efficacy scores, as well as the associated factors, such as retention of knowledge, belief and perception changes, whereas stroke risk factor control, for example, self-monitoring and quality of life, will be the secondary outcomes. The study should be able to determine if video narrative can induce a positive behavioral change towards stroke risk factor control via enhanced medication understanding and use self-efficacy. This intervention is innovative as it combines health belief, motivation, and role model concept to trigger self-efficacy in maintaining healthy behaviors and better disease management. ACTRN (12618000174280).

Effects of harness-attached transmitters on premigration and reproduction of Brant

USGS Publications Warehouse

Ward, David H.; Flint, Paul L.

1995-01-01

Radio transmitters are an important tool in waterfowl ecology studies, but little is known about their effects on free-ranging geese. We attached transmitters to female brant (Branta bernicla nigricans) to investigate migration schedules at a fall staging area, return rates to nesting grounds, and nesting rates of returning females in subsequent breeding seasons. Radio-tagged females (n = 62) carried either 35-g back-mounted transmitters attached with ribbon harnesses, or 26- or 32-g back-mounted transmitters affixed with plastic-coated wire harnesses (Dwyer 1972). Arrival and departure schedules at Izembek Lagoon, Alaska, did not differ (P > 0.05) between radio-tagged females and the entire population in 1987-89. Color-banded females with transmitters returned to the breeding colony in subsequent nesting seasons (1988-92) at a lower (P ≤ 0.003) rate (≤4%) than color-banded females without transmitters (57-83%). The 1 returning color-banded female with a transmitter did not breed, while an average 90% of the returning color-banded females without transmitters nested in subsequent breeding seasons (P = 0.005). Back-mounted, harness-attached transmitters may bias data in studies of waterfowl behavior, productivity, and survival.

Sport simulation as a form of implicit motor training in a geriatric athlete after stroke: a case report.

PubMed

Young, Sonia N; VanWye, William R; Wallmann, Harvey W

2018-06-25

To describe the use of sport simulation activities as a form of implicit motor learning training with a geriatric former athlete following a stroke. An active 76-year-old former professional male softball player presented to outpatient physical therapy with medical history of right stroke with left hemiparesis 2 weeks following onset of symptoms of impaired balance, coordination, gait, and motor planning. Initial physical therapy included gait, balance, and coordination training. Additional sport-related balance and coordination activities were later added to the treatment plan. After approximately 3 weeks of treatment, the patient was able to return to work and had dramatically improved balance, coordination, and gait with sport simulation activities. Implicit motor learning techniques were incorporated through sport and job task simulation activities along with task-oriented neuromuscular reeducation. The patient demonstrated improvements with gait, balance, gross motor function, and decreased fall risk.

On the flow generated by rotating flat plates of low aspect ratio

NASA Astrophysics Data System (ADS)

DeVoria, Adam C.

Low-aspect-ratio propulsors typically allow for high maneuverability at low-to-moderate speeds. This has made them the subject of much recent research aimed at employing such appendages on autonomous vehicles which are required to navigate tumultuous environments. This experimental investigation focuses on the fluid dynamic aspects associated with overly-simplified versions of such biologically-inspired propulsors. In doing so, fundamental contributions are made to the research area. The unsteady, three-dimensional flow of a low-aspect-ratio, trapezoidal flat plate undergoing rotation from rest at a 90° angle of attack and Reynolds numbers of O(103) is investigated experimentally. The objectives are to develop a straightforward protocol for vortex saturation, and to understand the effects of the root-to-tip flow for different velocity programs. The experiments are conducted in a glass-walled tank, and digital particle image velocimetry is used to obtain planar velocity measurements. A formation-parameter definition is investigated and is found to reasonably predict the state corresponding to the pinch-off of the initial tip vortex across the velocity programs tested. The flow in the region near the tip is relatively insensitive to Reynolds number over the range studied. The component normal to the plate is unaffected by total rotational amplitude while the tangential component has dependence on this angle. Also, an estimate of the first tip-vortex pinch-off time is obtained from the near-tip velocity data and agrees very well with values estimated using circulation. The angle of incidence of the bulk root-to-tip flow relative to the plate normal becomes more oblique with increasing rotational amplitude. Accordingly, the peak magnitude of the tangential velocity is also increased and as a result advects fluid momentum away from the plate at a higher rate. The more oblique impingement of the root-to-tip flow for increasing rotational amplitude is shown to have a distinct effect on the associated fluid dynamic force normal to the plate. For impulsive plate deceleration the time that a non-negligible force exists decreases, while for non-impulsive plate deceleration both this time and the relative force magnitude decrease for larger rotational amplitudes. In a separate set of experiments, force measurements are conducted on a similar plate that performs an advancing stroke from rest followed by a returning stroke. The parameters varied are the rotational amplitude of the motion and the rest time between the advancing and returning strokes. The unsteady normal forces track with the angular acceleration of the plate, with the added mass force peak in the returning stroke being larger than that in the advancing stroke. However, as the rest time is increased, the normal forces generated in each stroke become dynamically similar. The maximum total impulse is calculated from the force measurements and rapidly decays from its largest value at zero rest time and asymptotes to a constant with increased rest time. The direction of this impulse is also calculated and quickly approaches the direction about which the plate motion is symmetric. The largest additional impulse contribution obtained from executing a returning stroke within a finite time is approximately 18%. Increases in rotational amplitude initially increase the maximum total impulse, but it then plateaus at an amplitude of around 90 degrees. For non-zero rest times, any maxima of the impulse in a fixed direction are weak and necessarily reduced from the maximum possible impulse. For a nearly 100 degrees range of directions, the impulse is largest for rotational amplitudes between 75--90 degrees. The results are also applied to three types of propulsive configurations.

Re-emergence of modular brain networks in stroke recovery.

PubMed

Siegel, Joshua S; Seitzman, Benjamin A; Ramsey, Lenny E; Ortega, Mario; Gordon, Evan M; Dosenbach, Nico U F; Petersen, Steven E; Shulman, Gordon L; Corbetta, Maurizio

2018-04-01

Studies of stroke have identified local reorganization in perilesional tissue. However, because the brain is highly networked, strokes also broadly alter the brain's global network organization. Here, we assess brain network structure longitudinally in adult stroke patients using resting state fMRI. The topology and boundaries of cortical regions remain grossly unchanged across recovery. In contrast, the modularity of brain systems i.e. the degree of integration within and segregation between networks, was significantly reduced sub-acutely (n = 107), but partially recovered by 3 months (n = 85), and 1 year (n = 67). Importantly, network recovery correlated with recovery from language, spatial memory, and attention deficits, but not motor or visual deficits. Finally, in-depth single subject analyses were conducted using tools for visualization of changes in brain networks over time. This exploration indicated that changes in modularity during successful recovery reflect specific alterations in the relationships between different networks. For example, in a patient with left temporo-parietal stroke and severe aphasia, sub-acute loss of modularity reflected loss of association between frontal and temporo-parietal regions bi-hemispherically across multiple modules. These long-distance connections then returned over time, paralleling aphasia recovery. This work establishes the potential importance of normalization of large-scale modular brain systems in stroke recovery. Copyright © 2017. Published by Elsevier Ltd.

Ship-borne Radio and GLD360 Measurements of Intense Oceanic Lightning

NASA Astrophysics Data System (ADS)

Zoghzoghy, F. G.; Cohen, M.; Said, R.; Lehtinen, N. G.; Inan, U.

2013-12-01

Recent studies with the GLD360 lightning geo-location network have shown that the peak current intensity of cloud-to-ground (CG) lightning is more powerful over the ocean than over land. This remains a poorly understood phenomenon. The Stanford VLF group has recently deployed a Very Low Frequency (1 MHz sampling rate) radio receiver system aboard the NOAA Ronald W. Brown research vessel. The goal of this transatlantic experiment is to improve our understanding of oceanic lightning and to investigate the physical difference between oceanic and land lightning. When positioned reasonably close to deep oceanic thunderstorms, the LF-VLF receiver aboard the Ronald W. Brown detects the impulsive radio emissions from the return stroke, up to 1 MHz, which enables us to estimate the return-stroke waveform shapes generated by the lightning channel. In this presentation, we present our experimental setup and a summary of the data collected during the transatlantic voyages of the NOAA ship. We process lightning-generated waveforms, compare them to LF-VLF data from land lightning over Oklahoma, extract statistical patterns, and compare the data to numerical and analytical models.

Damage to metallic samples produced by measured lightning currents

NASA Technical Reports Server (NTRS)

Fisher, Richard J.; Schnetzer, George H.

1991-01-01

A total of 10 sample disks of 2024-T3 aluminum and 4130 ferrous steel were exposed to rocket-triggered lightning currents at the Kennedy Space Center test site. The experimental configuration was arranged so that the samples were not exposed to the preliminary streamer, wire-burn, or following currents that are associated with an upward-initiated rocket-triggered flash but which are atypical of naturally initiated lightning. Return-stroke currents and continuing currents actually attaching to the sample were measured, augmented by close-up video recordings of approximately 3 feet of the channel above the sample and by 16-mm movies with 5-ms resolution. From these data it was possible to correlate individual damage spots with streamer, return-stroke, and continuing currents that produced them. Substantial penetration of 80-mil aluminum was produced by a continuing current of submedian amplitude and duration, and full penetration of a 35-mil steel sample occurred under an eightieth percentile continuing current. The primary purpose of the data acquired in these experiments is for use in improving and quantifying the fidelity of laboratory simulations of lightning burnthrough.

Measured responses of internal enclosures and cables due to burnthrough penetration of weapon cases by lightning

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

Schnetzer, G.H.; Fisher, R.J.; Dinallo, M.A.

1994-08-01

The electrical effects of lightning penetration of the outer case of a weapon on internal structures, such as a firing set housing, and on samples of a flat, flexline detonator cable have been investigated experimentally. Maximum open-circuit voltages measured on either simulated structures (126 V) or the cable (46 V) located directly behind the point of penetration were well below any level that is foreseen to create a threat to nuclear safety. On the other hand, it was found that once full burnthrough of the barrier occurred, significant fractions of the incident continuing currents coupled to both the simulated internalmore » structure (up to 300 A) or to the cable sample (69 A) when each was electrically connected internally to case ground. No occurrence was observed of the injection of large amplitude currents from return strokes occurring after barrier penetration. Under circumstances in which small volumes of trapped gases exist behind penetration sites, rapid heating of the gas by return strokes occurring after burnthrough has been shown to produced large mechanical impulses to the adjacent surfaces.« less

Lightning spectra at 100,000 fps

NASA Astrophysics Data System (ADS)

McHarg, M. G.; Harley, J.; Haaland, R. K.; Edens, H. E.; Stenbaek-Nielsen, H.

2016-12-01

A fundamental understanding of lightning can be inferred from the spectral emissions resulting from the leader and return stroke channel. We examine an event recorded at 00:58:07 on 19 July 2015 at Langmuir Laboratory. We recorded lightning spectra using a 100 line per mm grating in front of a Phantom V2010 camera with an 85mm Nikon lens recording at 100,000 frames per second. Coarse resolution spectra (approximately 5nm resolution) are produced from approximately 400 nm to 800 nm for each frame. Electric field data from the Langmuir Electric Field Array for the 03:19:19 event show 10 V/m changes in the electric field associated with multiple return strokes visible in the spectral data. We used the spectral data to compare temperatures at the top, middle and bottom of the lightning channel. Lightning Mapping Array data at Langmuir for the 00:58:07 event show a complex flash extending 10 km in the East-West plane and 6 km in the North-South plane. The imagery data imply that this is a bolt-from-the-blue event.

Review of measurements of the RF spectrum of radiation from lightning

NASA Technical Reports Server (NTRS)

Levine, D. M.

1986-01-01

Measurements reported in the literature of the spectrum of electromagnetic radiation from lightning in the frequency range from 1 kHz to 1 GHz are reviewed. Measurements have been made either by monitoring the power received at individual frequencies using a narrow bandwidth recording device tuned to the frequencies under investigation or by recording the transient (time dependent) radiation with a wide bandwidth device and then Fourier transforming the waveform to obtain a spectrum. Measurements of the first type were made extensively in the 1950's and 1960's and several composite spectra have been deduced by normalizing the data of different investigators to common units of bandwidth and distance. The composite spectra tend to peak near 5 kHz and then decrease roughly as (frequency) to the -1, up to nearly 100 MHz where scatter in the data make the behavior uncertain. Measurements of the second type have been reported for return strokes, the stepped leader and for some intracloud processes. The spectrum of first return strokes obtained in this manner is very similar to the composite spectra obtained from the narrow-band measurements.

Gait training of patients after stroke using an electromechanical gait trainer combined with simultaneous functional electrical stimulation.

PubMed

Tong, Raymond K Y; Ng, Maple F W; Li, Leonard S W; So, Elaine F M

2006-09-01

This case report describes the implementation of gait training intervention that used an electromechanical gait trainer with simultaneous functional electrical stimulation (FES) for 2 patients with acute ischemic stroke. Two individuals with post-stroke hemiplegia of less than 6 weeks' duration participated in a 4-week gait training program as an adjunct to physical therapy received at a hospital. After the 4-week intervention, both patients were discharged from the hospital, and they returned after 6 months for a follow-up evaluation. By the end of the 4-week intervention, both patients had shown improvements in scores on the Barthel Index, Berg Balance Scale, Functional Ambulation Categories Scale, 5-m timed walking test, and Motricity Index. In the 6-month follow-up evaluation, both patients continued to have improvements in all outcome measures. This case report shows that, following the use of an electromechanical gait trainer simultaneously with FES, patients after acute stroke had improvements in gait performance, functional activities, balance, and motor control in the long term.

Practice variation in the structure of stroke rehabilitation in four rehabilitation centres in the Netherlands.

PubMed

Groeneveld, Iris F; Meesters, Jorit J L; Arwert, Henk J; Roux-Otter, Nienke; Ribbers, Gerard M; van Bennekom, Coen A M; Goossens, Paulien H; Vliet Vlieland, Thea P M

2016-03-01

To describe practice variation in the structure of stroke rehabilitation in 4 specialized multidisciplinary rehabilitation centres in the Netherlands. A multidisciplinary expert group formulated a set of 23 elements concerning the structure of inpatient and outpatient stroke rehabilitation, categorized into 4 domains: admission-related (n = 7), treatment-related (n = 10), client involvement-related (n = 2), and facilities-related (n = 4). In a cross-sectional study in 4 rehabilitation centres data on the presence and content of these elements were abstracted from treatment programmes and protocols. In a structured expert meeting consensus was reached on the presence of practice variation per element. Practice variation was observed in 22 of the 23 structure elements. The element "strategies for patient involvement" appeared similar in all rehabilitation centres, whereas differences were found in the elements regarding admission, exclusion and discharge criteria, patient subgroups, care pathways, team meetings, clinical assessments, maximum time to admission, aftercare and return to work modules, health professionals, treatment facilities, and care-giver involvement. Practice variation was found in a wide range of aspects of the structure of stroke rehabilitation.

Symptoms of Insomnia and Sleep Duration and Their Association with Incident Strokes: Findings from the Population-Based MONICA/KORA Augsburg Cohort Study.

PubMed

Helbig, A Katharina; Stöckl, Doris; Heier, Margit; Ladwig, Karl-Heinz; Meisinger, Christa

2015-01-01

To examine the relationship between symptoms of insomnia and sleep duration and incident total (non-fatal plus fatal) strokes, non-fatal strokes, and fatal strokes in a large cohort of men and women from the general population in Germany. In four population-based MONICA (monitoring trends and determinants in cardiovascular disease)/KORA (Cooperative Health Research in the Region of Augsburg) surveys conducted between 1984 and 2001, 17,604 men and women (aged 25 to 74 years) were asked about issues like sleep, health behavior, and medical history. In subsequent surveys and mortality follow-ups, incident stroke cases (cerebral hemorrhage, ischemic stroke, transient ischemic attack, unknown stroke type) were gathered prospectively until 2009. Sex-specific hazard ratios (HR) and their 95% confidence intervals (CI) were estimated using sequential Cox proportional hazards regression models. During a mean follow-up of 14 years, 917 strokes (710 non-fatal strokes and 207 fatal strokes) were observed. Trouble falling asleep and difficulty staying asleep were not significantly related to any incident stroke outcome in either sex in the multivariable models. Among men, the HR for the association between short (≤5 hours) and long (≥10 hours) daily sleep duration and total strokes were 1.44 (95% CI: 1.01-2.06) and 1.63 (95% CI: 1.16-2.29), after adjustment for basic confounding variables. As for non-fatal strokes and fatal strokes, in the analyses adjusted for age, survey, education, physical activity, alcohol consumption, smoking habits, body mass index, hypertension, diabetes, and dyslipidemia, the increased risks persisted, albeit somewhat attenuated, but no longer remained significant. Among women, in the multivariable analyses the quantity of sleep was also not related to any stroke outcome. In the present study, symptoms of insomnia and exceptional sleep duration were not significantly predictive of incident total strokes, non-fatal strokes, and fatal strokes in either sex.

Symptoms of Insomnia and Sleep Duration and Their Association with Incident Strokes: Findings from the Population-Based MONICA/KORA Augsburg Cohort Study

PubMed Central

Helbig, A. Katharina; Stöckl, Doris; Heier, Margit; Ladwig, Karl-Heinz; Meisinger, Christa

2015-01-01

Objective To examine the relationship between symptoms of insomnia and sleep duration and incident total (non-fatal plus fatal) strokes, non-fatal strokes, and fatal strokes in a large cohort of men and women from the general population in Germany. Methods In four population-based MONICA (monitoring trends and determinants in cardiovascular disease)/KORA (Cooperative Health Research in the Region of Augsburg) surveys conducted between 1984 and 2001, 17,604 men and women (aged 25 to 74 years) were asked about issues like sleep, health behavior, and medical history. In subsequent surveys and mortality follow-ups, incident stroke cases (cerebral hemorrhage, ischemic stroke, transient ischemic attack, unknown stroke type) were gathered prospectively until 2009. Sex-specific hazard ratios (HR) and their 95% confidence intervals (CI) were estimated using sequential Cox proportional hazards regression models. Results During a mean follow-up of 14 years, 917 strokes (710 non-fatal strokes and 207 fatal strokes) were observed. Trouble falling asleep and difficulty staying asleep were not significantly related to any incident stroke outcome in either sex in the multivariable models. Among men, the HR for the association between short (≤5 hours) and long (≥10 hours) daily sleep duration and total strokes were 1.44 (95% CI: 1.01–2.06) and 1.63 (95% CI: 1.16–2.29), after adjustment for basic confounding variables. As for non-fatal strokes and fatal strokes, in the analyses adjusted for age, survey, education, physical activity, alcohol consumption, smoking habits, body mass index, hypertension, diabetes, and dyslipidemia, the increased risks persisted, albeit somewhat attenuated, but no longer remained significant. Among women, in the multivariable analyses the quantity of sleep was also not related to any stroke outcome. Conclusion In the present study, symptoms of insomnia and exceptional sleep duration were not significantly predictive of incident total strokes, non-fatal strokes, and fatal strokes in either sex. PMID:26230576

Actigraphy--a useful tool for motor activity monitoring in stroke patients.

PubMed

Reiterer, Veronika; Sauter, Cornelia; Klösch, Gerhard; Lalouschek, Wolfgang; Zeitlhofer, Josef

2008-01-01

The aim of the present study was the evaluation of actigraphy as a tool to objectify the recovery process after motor paresis due to stroke. The motor activity of both arms of patients suffering from stroke was actigraphically recorded at four different time points during the course of rehabilitation: 24-36 h, 5-7 days, 3 months, and 6 months after stroke. Motor activity monitored by wrist-worn actigraphs located at the impaired side revealed an increase in activity between the first two time points and the subsequent ones. Additionally, actigraphic recordings showed lower total motor activity at the impaired side as compared to the nonimpaired side. A significant positive correlation was found between the actigraphically recorded motor activity and the results of the Scandinavian Stroke scale, the Barthel Index, the Rankin Scale Score and with the Motoricity Index during the 1st week, which corresponds to the time when neurological deficits were most pronounced. Our results suggest that actigraphy is a useful tool in the objective evaluation of motor activity after stroke. Moreover, actigraphy covers additional aspects that are not reflected by the usual stroke scales in a clinical situation. Copyright 2008 S. Karger AG, Basel.

Mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS) may respond to adjunctive ketogenic diet.

PubMed

Steriade, Claude; Andrade, Danielle M; Faghfoury, Hanna; Tarnopolsky, Mark A; Tai, Peter

2014-05-01

Mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS) syndrome can present management challenges. Refractory seizures and stroke-like episodes leading to disability are common. We analyzed the clinical, electrophysiologic, and radiologic data of a 22-year-old woman with multiple episodes of generalized and focal status epilepticus and migratory cortical stroke-like lesions who underwent muscle biopsy for mitochondrial genome sequencing. Although initial mitochondrial genetic testing was negative, muscle biopsy demonstrated a mitochondrial DNA disease-causing mutation (m.3260A > G). New antiepileptic medications were added with each episode of focal status epilepticus with only temporary improvement, until a modified ketogenic diet and magnesium were introduced, leading to seizure freedom despite development of a new stroke-like lesion, and subsequent decrease in frequency of stroke-like episodes. We propose a metabolic model in which the ketogenic diet may lead to improvement of the function of respiratory chain complexes. The ketogenic diet may lead to improvement of mitochondrial dysfunction in MELAS, which in turn may promote better seizure control and less frequent stroke-like episodes. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

Health Inequalities Associated with Post-Stroke Visual Impairment in the United Kingdom and Ireland: A Systematic Review

PubMed Central

Hanna, K. L.; Rowe, F. J.

2017-01-01

ABSTRACT The aim of this study was to report on the health inequalities facing stroke survivors with visual impairments as described in the current literature. A systemic review of the literature was conducted to investigate the potential health inequalities facing stroke survivors with subsequent visual impairments. A quality-of-evidence and risk-of-bias assessment was conducted for each of the included articles using the appropriate tool dependent on the type of article. Only four articles discussed health inequalities affecting stroke survivors with visual impairment specifically. A further 23 articles identified health inequalities after stroke, and 38 reported on health inequalities within the visually impaired UK or Irish population. Stroke survivors with visual impairment face inconsistency in eye care provision nationally, along with variability in the assessment and management of visual disorders. The subgroups identified as most at risk were females; black ethnicity; lower socioeconomic status; older age; and those with lower education attainment. The issue of inconsistent service provision for this population must be addressed in future research. Further research must be conducted in order to firmly establish whether or not stroke survivors are at risk of the aforementioned sociodemographic and economic inequalities. PMID:28512502

Pre-stroke seizures: A nationwide register-based investigation.

PubMed

Zelano, Johan; Larsson, David; Kumlien, Eva; Åsberg, Signild

2017-07-01

The relationship between cerebrovascular disease and seizures is clearly illustrated by poststroke epilepsy. Seizures can also be the first manifestation of cerebrovascular disease and case-control studies have demonstrated that seizures carry an increased risk of subsequent stroke. Thus, seizures could serve as a marker for vascular risk that merits intervention, but more data is needed before proper trials can be conducted. The occurrence of pre-stroke seizures has not been assessed on a national scale. We asked what proportion of strokes in middle-aged and elderly patients was preceded by seizures. All patients over 60 years of age with first-ever stroke in 2005-2010 (n=92,596) were identified in the Swedish stroke register (Riksstroke) and cross-sectional data on a history of a first seizure or epilepsy diagnosis in the ten years preceding stroke were collected from national patient registers with mandatory reporting. 1372 patients (1.48%) had a first seizure or epilepsy diagnosis registered less than ten years prior to the index stroke. The mean latency between seizure and stroke was 1474days (SD 1029 days). Seizures or epilepsy preceded 1.48% of strokes in patients >60years of age. Based on recent national incidence figures, 5-20% of incident cases of seizures or epilepsy after 60 years of age could herald stroke, depending on age group. These proportions are of a magnitude that merit further study on how to reduce the risk of stroke in patients with late-onset seizures or epilepsy. Copyright © 2017 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Microbubble signal and trial of org in acute stroke treatment (TOAST) classification in ischemic stroke.

PubMed

Lee, Chan-Hyuk; Kang, Hyun Goo; Lee, Ji Sung; Ryu, Han Uk; Jeong, Seul-Ki

2018-07-15

Right-to-left shunt (RLS) through a patent foramen ovale (PFO) is likely associated with ischemic stroke. Many studies have attempted to demonstrate the association between RLS and ischemic stroke. However, information on the association between the degree of RLS and the subtypes of ischemic stroke categorized by the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification is lacking. This was a retrospective study involving 508 patients with ischemic stroke who underwent a transcranial Doppler (TCD) microbubble test between 2013 and 2015. The degree of RLS was divided into 4 grades according to the microbubble signal (MBS) as follows: no MBS, grade 1; MBS < 20, grade 2; MBS > 20, grade 3; curtain sign, grade 4. The degree of RLS and the type of ischemic stroke as classified by TOAST were analyzed and compared with other clinical information and laboratory findings. The higher RLS grade was associated with the cardioembolism (CE) and stroke of undetermined etiology (SUE), and the microbubble signals were inversely related with small vessel disease (SVD). An MBS higher than grade 3 showed a 2.95-fold higher association with SUE than large artery atherosclerosis (LAA), while grade 4 MBS revealed an approximately 8-fold higher association with SUE than LAA. RLS identified by the TCD microbubble test was significantly and independently associated with cryptogenic ischemic stroke (negative evaluation). Subsequent studies are needed to determine the biologic relationship between RLS and ischemic stroke, particularly the cryptogenic subtype of ischemic stroke. Copyright © 2018 Elsevier B.V. All rights reserved.

Astrocytes, therapeutic targets for neuroprotection and neurorestoration in ischemic stroke

PubMed Central

Liu, Zhongwu; Chopp, Michael

2015-01-01

Astrocytes are the most abundant cell type within the central nervous system. They play essential roles in maintaining normal brain function, as they are a critical structural and functional part of the tripartite synapses and the neurovascular unit, and communicate with neurons, oligodendrocytes and endothelial cells. After an ischemic stroke, astrocytes perform multiple functions both detrimental and beneficial, for neuronal survival during the acute phase. Aspects of the astrocytic inflammatory response to stroke may aggravate the ischemic lesion, but astrocytes also provide benefit for neuroprotection, by limiting lesion extension via anti-excitotoxicity effects and releasing neurotrophins. Similarly, during the late recovery phase after stroke, the glial scar may obstruct axonal regeneration and subsequently reduce the functional outcome; however, astrocytes also contribute to angiogenesis, neurogenesis, synaptogenesis, and axonal remodeling, and thereby promote neurological recovery. Thus, the pivotal involvement of astrocytes in normal brain function and responses to an ischemic lesion designates them as excellent therapeutic targets to improve functional outcome following stroke. In this review, we will focus on functions of astrocytes and astrocyte-mediated events during stroke and recovery. We will provide an overview of approaches on how to reduce the detrimental effects and amplify the beneficial effects of astrocytes on neuroprotection and on neurorestoration post stroke, which may lead to novel and clinically relevant therapies for stroke. PMID:26455456

The influence of the day of the week of hospital admission on the prognosis of stroke patients.

PubMed

Barros, Juliana B; Goulart, Alessandra Carvalho; Alencar, Airlane P; Lotufo, Paulo A; Bensenor, Isabela M

2013-04-01

This study aimed to evaluate the weekday and weekend distribution of stroke case hospital admissions and their respective prognosis based on a sample from the Estudo de Mortalidade e Morbidade do Acidente Vascular Cerebral (EMMA), a cohort of stroke patients admitted to a community hospital in the city of São Paulo, Brazil. We ascertained all consecutive cases of first-time strokes between April 2006 and December 2008 and performed a subsequent one-year follow-up. No association was found between frequency of hospital admissions due to ischemic and hemorrhagic strokes and the specific day of the week on which the admission occurred. However, ten-day and twelve-month case-fatality was higher in hemorrhagic stroke patients admitted at the weekend. We also found that intracerebral hemorrhage patients admitted on weekends had a worse survival rate (50%) compared with those admitted during weekdays (25.6%, P log-rank = 0.03). We found a multivariate hazard ratio of 2.49 (95%CI: 1.10-5.81, P trend = 0.03) for risk of death at the weekend compared to weekdays for intracerebral hemorrhage cases. No difference in survival was observed with respect to the overall sample of stroke or ischemic stroke patients.

The Quest for Arterial Recanalization in Acute Ischemic Stroke-The Past, Present and the Future

PubMed Central

L.L.Yeo, Leonard; Sharma, Vijay K

2013-01-01

Ischemic stroke is one of the major causes of mortality and long-term disability. In the recent past, only very few treatment options were available and a considerable proportion of stroke survivors remained permanently disabled. However, over the last 2 decades rapid advances in acute stroke care have resulted in a corresponding improvement in mortality rates and functional outcomes. In this review, we describe the evolution of systemic thrombolytic agents and various interventional devices, their current status as well as some of the future prospects. We reviewed literature pertaining to acute ischemic stroke reperfusion treatment. We explored the current accepted treatment strategies to attain cerebral reperfusion via intravenous modalities and compare and contrast them within the boundaries of their clinical trials. Subsequently we reviewed the trials for interventional devices for acute ischemic stroke, categorizing them into thrombectomy devices, aspiration devices, clot disruption devices and thrombus entrapment devices. Finally we surveyed several of the alternative reperfusion strategies available. We also shed some light on the controversies surrounding the current strategies of treatment of acute ischemic stroke. Acute invasive interventional strategies continue to improve along with the noninvasive modalities. Both approaches appear promising. We conducted a comprehensive chronological review of the existing treatments as well as upcoming remedies for acute ischemic stroke. PMID:23864913

On the Viability of Diffusion MRI-Based Microstructural Biomarkers in Ischemic Stroke

PubMed Central

Boscolo Galazzo, Ilaria; Brusini, Lorenza; Obertino, Silvia; Zucchelli, Mauro; Granziera, Cristina; Menegaz, Gloria

2018-01-01

Recent tract-based analyses provided evidence for the exploitability of 3D-SHORE microstructural descriptors derived from diffusion MRI (dMRI) in revealing white matter (WM) plasticity. In this work, we focused on the main open issues left: (1) the comparative analysis with respect to classical tensor-derived indices, i.e., Fractional Anisotropy (FA) and Mean Diffusivity (MD); and (2) the ability to detect plasticity processes in gray matter (GM). Although signal modeling in GM is still largely unexplored, we investigated their sensibility to stroke-induced microstructural modifications occurring in the contralateral hemisphere. A more complete picture could provide hints for investigating the interplay of GM and WM modulations. Ten stroke patients and ten age/gender-matched healthy controls were enrolled in the study and underwent diffusion spectrum imaging (DSI). Acquisitions at three and two time points (tp) were performed on patients and controls, respectively. For all subjects and acquisitions, FA and MD were computed along with 3D-SHORE-based indices [Generalized Fractional Anisotropy (GFA), Propagator Anisotropy (PA), Return To the Axis Probability (RTAP), Return To the Plane Probability (RTPP), and Mean Square Displacement (MSD)]. Tract-based analysis involving the cortical, subcortical and transcallosal motor networks and region-based analysis in GM were successively performed, focusing on the contralateral hemisphere to the stroke. Reproducibility of all the indices on both WM and GM was quantitatively proved on controls. For tract-based, longitudinal group analyses revealed the highest significant differences across the subcortical and transcallosal networks for all the indices. The optimal regression model for predicting the clinical motor outcome at tp3 included GFA, PA, RTPP, and MSD in the subcortical network in combination with the main clinical information at baseline. Region-based analysis in the contralateral GM highlighted the ability of anisotropy indices in discriminating between groups mainly at tp1, while diffusivity indices appeared to be altered at tp2. 3D-SHORE indices proved to be suitable in probing plasticity in both WM and GM, further confirming their viability as a novel family of biomarkers in ischemic stroke in WM and revealing their potential exploitability in GM. Their combination with tensor-derived indices can provide more detailed insights of the different tissue modulations related to stroke pathology. PMID:29515362

Systolic and Diastolic Left Ventricular Mechanics during and after Resistance Exercise.

PubMed

Stöhr, Eric J; Stembridge, Mike; Shave, Rob; Samuel, T Jake; Stone, Keeron; Esformes, Joseph I

2017-10-01

To improve the current understanding of the impact of resistance exercise on the heart, by examining the acute responses of left ventricular (LV) strain, twist, and untwisting rate ("LV mechanics"). LV echocardiographic images were recorded in systole and diastole before, during and immediately after (7-12 s) double-leg press exercise at two intensities (30% and 60% of maximum strength, one-repetition maximum). Speckle tracking analysis generated LV strain, twist, and untwisting rate data. Additionally, beat-by-beat blood pressure was recorded and systemic vascular resistance (SVR) and LV wall stress were calculated. Responses in both exercise trials were statistically similar (P > 0.05). During effort, stroke volume decreased, whereas SVR and LV wall stress increased (P < 0.05). Immediately after effort, stroke volume returned to baseline, whereas SVR and wall stress decreased (P < 0.05). Similarly, acute exercise was accompanied by a significant decrease in systolic parameters of LV muscle mechanics (P < 0.05). However, diastolic parameters, including LV untwisting rate, were statistically unaltered (P > 0.05). Immediately after exercise, systolic LV mechanics returned to baseline levels (P < 0.05) but LV untwisting rate increased significantly (P < 0.05). A single, acute bout of double-leg press resistance exercise transiently reduces systolic LV mechanics, but increases diastolic mechanics after exercise, suggesting that resistance exercise has a differential impact on systolic and diastolic heart muscle function. The findings may explain why acute resistance exercise has been associated with reduced stroke volume but chronic exercise training may result in increased LV volumes.

A rule-based, dose-finding design for use in stroke rehabilitation research: methodological development.

PubMed

Colucci, E; Clark, A; Lang, C E; Pomeroy, V M

2017-12-01

Dose-optimisation studies as precursors to clinical trials are rare in stroke rehabilitation. To develop a rule-based, dose-finding design for stroke rehabilitation research. 3+3 rule-based, dose-finding study. Dose escalation/de-escalation was undertaken according to preset rules and a mathematical sequence (modified Fibonacci sequence). The target starting daily dose was 50 repetitions for the first cohort. Adherence was recorded by an electronic counter. At the end of the 2-week training period, the adherence record indicated dose tolerability (adherence to target dose) and the outcome measure indicated dose benefit (10% increase in motor function). The preset increment/decrease and checking rules were then applied to set the dose for the subsequent cohort. The process was repeated until preset stopping rules were met. Participants had a mean age of 68 (range 48 to 81) years, and were a mean of 70 (range 9 to 289) months post stroke with moderate upper limb paresis. A custom-built model of exercise-based training to enhance ability to open the paretic hand. Repetitions per minute of extension/flexion of paretic digits against resistance. Usability of the preset rules and whether the maximally tolerated dose was identifiable. Five cohorts of three participants were involved. Discernibly different doses were set for each subsequent cohort (i.e. 50, 100, 167, 251 and 209 repetitions/day). The maximally tolerated dose for the model training task was 209 repetitions/day. This dose-finding design is a feasible method for use in stroke rehabilitation research. Copyright © 2017 Chartered Society of Physiotherapy. All rights reserved.

Pathophysiology of the vascular wall and its relevance for cerebrovascular disorders in aged rodents.

PubMed

Popa-Wagner, A; Pirici, D; Petcu, E B; Mogoanta, L; Buga, A-M; Rosen, C L; Leon, R; Huber, J

2010-08-01

Chronic hypertension and cerebral amyloid angiopathy (CAA) are the main pathologies which can induce the rupture of cerebral vessels and intracerebral hemorrhages, as a result of degenerative changes in the vascular wall. A lot of progress has been made in this direction since the successful creation of the first mouse model for the study of Alzheimer's disease (AD), as the spectrum of AD pathology includes a plethora of changes found in pure cerebrovascular diseases. We describe here some of these mouse models having important vascular changes that parallel human AD pathology, and more importantly, we show how these models have helped us understand more about the mechanisms that lead to CAA formation. An important cellular event associated with reduced structural and functional recovery after stroke in aged animals is the early formation of a scar in the infarcted region that impairs subsequent neural recovery and repair. We review recent evidence showing that the rapid formation of the glial scar following stroke in aged rats is associated with premature cellular proliferation that originates primarily from the walls of capillaries in the corpus callosum adjacent to the infarcted region. After stroke several vascular mechanisms are turned-on immediately to protect the brain from further damage and help subsequent neuroregeneration and functional recovery. Although does occur after stroke, vasculogenesis is overshadowed in its protective/restorative role by the angiogenesis and arteriogenesis. Understanding the basic mechanisms underlying functional recovery after cerebral stroke in aging subjects is likely to yield new insights into the treatment of brain injury in the clinic.

Statin use increases the risk of depressive disorder in stroke patients: a population-based study.

PubMed

Kang, Jiunn-Horng; Kao, Li-Ting; Lin, Herng-Ching; Tsai, Ming-Chieh; Chung, Shiu-Dong

2015-01-15

This study aimed to explore the risk for depressive disorder (DD) among stroke patients with statin use. Totally, 11,218 patients who had a first-time acute hospitalization for stroke were identified from Taiwan's Longitudinal Health Insurance Database 2000. We individually followed each study subject for a 1-year period to identify those patients who were subsequently diagnosed with DD during the follow-up period. We found that the incidence rate of DD during the 1-year follow-up period was 5.52 (95% CI: 4.70-6.43) and 3.46 (95% CI: 3.08-3.88) per 100 person-years for stroke patients who were statin users and nonusers, respectively. Cox proportional hazards regressions revealed that the adjusted hazard ratio (HR) for DD during the 1-year follow-up period was 1.59 for stroke patients who were statin users compared to those who were non-statin users. We further found that the adjusted HR for DD for stroke patients who were regular statin users was 1.65 compared to stroke patients who had never been prescribed statin. However, there was no increased hazard of DD for stroke patients who were irregular statin users compared to stroke patients who had never been prescribed statin (HR: 1.22, 95% CI: 0.70-2.11). Copyright © 2014. Published by Elsevier B.V.

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.

Determinants in Adolescence of Stroke-Related Hospital Stay Duration in Men: A National Cohort Study.

PubMed

Bergh, Cecilia; Udumyan, Ruzan; Appelros, Peter; Fall, Katja; Montgomery, Scott

2016-09-01

Physical and psychological characteristics in adolescence are associated with subsequent stroke risk. Our aim is to investigate their relevance to length of hospital stay and risk of second stroke. Swedish men born between 1952 and 1956 (n=237 879) were followed from 1987 to 2010 using information from population-based national registers. Stress resilience, body mass index, cognitive function, physical fitness, and blood pressure were measured at compulsory military conscription examinations in late adolescence. Joint Cox proportional hazards models estimated the associations of these characteristics with long compared with short duration of stroke-related hospital stay and with second stroke compared with first. Some 3000 men were diagnosed with nonfatal stroke between ages 31 and 58 years. Low stress resilience, underweight, and higher systolic blood pressure (per 1-mm Hg increase) during adolescence were associated with longer hospital stay (compared with shorter) in ischemic stroke, with adjusted relative hazard ratios (and 95% confidence intervals) of 1.46 (1.08-1.89), 1.41 (1.04-1.91), and 1.01 (1.00-1.02), respectively. Elevated systolic and diastolic blood pressures during adolescence were associated with longer hospital stay in men with intracerebral hemorrhage: 1.01 (1.00-1.03) and 1.02 (1.00-1.04), respectively. Among both stroke types, obesity in adolescence conferred an increased risk of second stroke: 2.06 (1.21-3.45). Some characteristics relevant to length of stroke-related hospital stay and risk of second stroke are already present in adolescence. Early lifestyle influences are of importance not only to stroke risk by middle age but also to recurrence and use of healthcare resources among stroke survivors. © 2016 American Heart Association, Inc.

The Christchurch earthquake stroke incidence study.

PubMed

Wu, Teddy Y; Cheung, Jeanette; Cole, David; Fink, John N

2014-03-01

We examined the impact of major earthquakes on acute stroke admissions by a retrospective review of stroke admissions in the 6 weeks following the 4 September 2010 and 22 February 2011 earthquakes. The control period was the corresponding 6 weeks in the previous year. In the 6 weeks following the September 2010 earthquake there were 97 acute stroke admissions, with 79 (81.4%) ischaemic infarctions. This was similar to the 2009 control period which had 104 acute stroke admissions, of whom 80 (76.9%) had ischaemic infarction. In the 6 weeks following the February 2011 earthquake, there were 71 stroke admissions, and 61 (79.2%) were ischaemic infarction. This was less than the 96 strokes (72 [75%] ischaemic infarction) in the corresponding control period. None of the comparisons were statistically significant. There was also no difference in the rate of cardioembolic infarction from atrial fibrillation between the study periods. Patients admitted during the February 2011 earthquake period were less likely to be discharged directly home when compared to the control period (31.2% versus 46.9%, p=0.036). There was no observable trend in the number of weekly stroke admissions between the 2 weeks leading to and 6 weeks following the earthquakes. Our results suggest that severe psychological stress from earthquakes did not influence the subsequent short term risk of acute stroke, but the severity of the earthquake in February 2011 and associated civil structural damages may have influenced the pattern of discharge for stroke patients. Copyright © 2013 Elsevier Ltd. All rights reserved.

Genetics of ischaemic stroke; single gene disorders.

PubMed

Flossmann, Enrico

2006-08-01

Examples of single gene disorders have been described for all major subtypes of ischaemic stroke: accelerated atherosclerosis and subsequent thrombo-embolism (e.g. homocysteinuria), weakening of connective tissue resulting in arterial dissections (e.g. Ehler-Danlos type IV), disorders of cerebral small vessels (e.g. cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy and the collagen COL4A1 mutation), disorders increasing the thrombogenic potential of the heart through affecting the myocardium or the heart valves or through disturbance of the heart rhythm (e.g. hypertrophic cardiomyopathy), mitochondrial cytopathies increasing cerebral tissue susceptibility to insults (e.g. mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes), and finally disorders of coagulation that can either directly cause stroke or act synergistically with the aforementioned abnormalities (e.g. sickle cell disease). Most of these disorders are rare but they are important to consider particularly in young patients with stroke, those with a family history or those who have other characteristics of a particular syndrome.

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.

Incidence of cerebral infarction after radiotherapy for pituitary adenoma

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

Flickinger, J.C.; Nelson, P.B.; Taylor, F.H.

1989-06-15

The incidence of cerebral infarction was studied in 156 patients irradiated for treatment of pituitary adenomas. Seven patients experienced strokes at intervals of 3.2 to 14.6 years after irradiation. The observed incidence was not significantly greater than the expected value of 3.5 strokes (P = 0.078). Six strokes occurred in patients receiving equivalent doses (ED) of 1070 ret or more (observed to expected ratio 3.87, significantly elevated; P less than 0.001). Univariate log-rank analysis showed that the risk of stroke was significantly higher (P = 0.010) in patients receiving an ED of 1070 ret or more (4180 cGy/22 fractions) thanmore » those receiving lower doses. Multivariate analysis, however, demonstrated that the increased risk of stroke was associated only with increasing age (P less than 0.0001), not ED (P = 0.148). Due to these inconsistent statistical results, no definitive conclusions could be reached about the relationship between radiation dose to the pituitary and subsequent cerebral infarction.« less

Predicting fitness-to-drive following stroke using the Occupational Therapy - Driver Off Road Assessment Battery.

PubMed

Unsworth, Carolyn A; Baker, Anne; Lannin, Natasha; Harries, Priscilla; Strahan, Janene; Browne, Matthew

2018-02-28

It is difficult to determine if, or when, individuals with stroke are ready to undergo on-road fitness-to-drive assessment. The Occupational Therapy - Driver Off Road Assessment Battery was developed to determine client suitability to resume driving. The predictive validity of the Battery needs to be verified for people with stroke. Examine the predictive validity of the Occupational Therapy - Driver Off Road Assessment Battery for on-road performance among people with stroke. Off-road data were collected from 148 people post stroke on the Battery and the outcome of their on-road assessment was recorded as: fit-to-drive or not fit-to-drive. The majority of participants (76%) were able to resume driving. A classification and regression tree (CART) analysis using four subtests (three cognitive and one physical) from the Battery demonstrated an area under the curve (AUC) of 0.8311. Using a threshold of 0.5, the model correctly predicted 98/112 fit-to-drive (87.5%) and 26/36 people not fit-to-drive (72.2%). The three cognitive subtests from the Occupational Therapy - Driver Off Road Assessment Battery and potentially one of the physical tests have good predictive validity for client fitness-to-drive. These tests can be used to screen client suitability for proceeding to an on-road test following stroke. Implications for Rehabilitation: Following stroke, drivers should be counseled (including consideration of local legislation) concerning return to driving. The Occupational Therapy - Driver Off Road Assessment Battery can be used in the clinic to screen people for suitability to undertake on road assessment. Scores on four of the Occupational Therapy - Driver Off Road Assessment Battery subtests are predictive of resumption of driving following stroke.

Small negative cloud-to-ground lightning reports at the NASA Kennedy Space Center and Air Force Eastern Range

NASA Astrophysics Data System (ADS)

Wilson, Jennifer G.; Cummins, Kenneth L.; Krider, E. Philip

2009-12-01

The NASA Kennedy Space Center (KSC) and Air Force Eastern Range (ER) use data 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™ (NLDN), and a volumetric lightning mapping array, the Lightning Detection and Ranging (LDAR) system, to monitor and characterize lightning that is potentially hazardous to launch or ground operations. Data obtained from these systems during June-August 2006 have been examined to check the classification of small, negative CGLSS reports that have an estimated peak current, ∣Ip∣ less than 7 kA, and to determine the smallest values of Ip that are produced by first strokes, by subsequent strokes that create a new ground contact (NGC), and by subsequent strokes that remain in a preexisting channel (PEC). The results show that within 20 km of the KSC-ER, 21% of the low-amplitude negative CGLSS reports were produced by first strokes, with a minimum Ip of -2.9 kA; 31% were by NGCs, with a minimum Ip of -2.0 kA; and 14% were by PECs, with a minimum Ip of -2.2 kA. The remaining 34% were produced by cloud pulses or lightning events that we were not able to classify.

The Mataró Stroke Registry: a 10-year registry in a community hospital.

PubMed

Palomeras Soler, E; Fossas Felip, P; Casado Ruiz, V; Cano Orgaz, A; Sanz Cartagena, P; Muriana Batiste, D

2015-06-01

A prospective stroke registry leads to improved knowledge of the disease. We present data on the Mataró Hospital Registry. In February-2002 a prospective stroke registry was initiated in our hospital. It includes sociodemographic data, previous diseases, clinical, topographic, etiological and prognostic data. We have analyzed the results of the first 10 years. A total of 2,165 patients have been included, 54.1% male, mean age 73 years. The most frequent vascular risk factor was hypertension (65.4%). Median NIHSS on admission: 3 (interquartile range, 1-8). Stroke subtype: 79.7% ischemic strokes, 10.9% hemorrhagic, and 9.4% TIA. Among ischemic strokes, the etiology was cardioembolic in 26.5%, large-vessel disease in 23.7%, and small-vessel in 22.9%. The most frequent topography of hemorrhages was lobar (47.4%), and 54.8% were attributed to hypertension. The median hospital stay was 8 days. At discharge, 60.7% of patients were able to return directly to their own home, and 52.7% were independent for their daily life activities. After 3 months these percentages were 76.9% and 62.9%, respectively. Hospital mortality was 6.5%, and after 3 months 10.9%. Our patient's profile is similar to those of other series, although the severity of strokes was slightly lower. Length of hospital stay, short-term and medium term disability, and mortality rates are good, if we compare them with other series. Copyright © 2013 Sociedad Española de Neurología. Published by Elsevier España, S.L.U. All rights reserved.

Driving simulation for evaluation and rehabilitation of driving after stroke.

PubMed

Akinwuntan, Abiodun Emmanuel; Wachtel, Jerry; Rosen, Peter Newman

2012-08-01

Driving is an important activity of daily living. Loss of driving privileges can lead to depression, decreased access to medical care, and increased healthcare costs. The ability to drive is often affected after stroke. In approximately 30% of stroke survivors, it is clear from the onset that driving will no longer be possible. Approximately 33% of survivors will be able to return to driving with little or no retraining, and 35% will require driving-related rehabilitation before they can resume safe driving again. The ability to drive is not routinely evaluated after stroke, and there is no established rehabilitation program for poststroke driving. When driving evaluation does occur, it is not always clear which tests are the most salient for accurately assessing poststroke driving ability. Investigators have examined the efficacy of various methodologies to predict driving performance after stroke and have found mixed results, with each method having unique weaknesses, including poor predictive ability, poor face validity, poor sensitivity or specificity, and limited reliability. Here we review common models of driving to gain insight into why single-construct visual or cognitive off-road measures are inadequate for evaluating driving, a complex and dynamic activity that involves timely interaction of multiple motor, visual, cognitive, and perceptual skills. We also examine the potential for driving simulators to overcome the problems currently faced in the evaluation and rehabilitation of driving after stroke. Finally, we offer suggestions for the future direction of simulator-based poststroke driving evaluation and training. Copyright © 2012 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Detection of VHF lightning from GPS orbit

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

Suszcynsky, D. M.

2003-01-01

Satellite-based VHF' lightning detection is characterized at GPS orbit by using a VHF receiver system recently launched on the GPS SVN 54 satellite. Collected lightning triggers consist of Narrow Bipolar Events (80%) and strong negative return strokes (20%). The results are used to evaluate the performance of a future GPS-satellite-based VHF global lightning monitor.

Current to the ionosphere following a lightning stroke

NASA Technical Reports Server (NTRS)

Hale, L. C.; Baginski, M. E.

1987-01-01

A simple analytical expression for calculating the total current waveform to the ionosphere after a lightning stroke is derived. The validity of this expression is demonstrated by comparison with a more rigorous computer solution of Maxwell's equations. The analytic model demonstrates that the temporal variation of the current induced in the ionosphere and global circuit and the corresponding return current in the earth depends on the conductivity profile at intervening altitudes in the middle atmosphere. A conclusion is that capacitative coupling may provide tighter coupling between the lower atmosphere and the ionosphere than usually considered, in both directions, which may help to explain observations which seem to indicate that magnetospheric phenomena may in some instances trigger lightning.

Analysis of Chinese Donors’ Return Behavior

PubMed Central

Guo, Nan; Wang, Jingxing; Ness, Paul; Yao, Fuzhu; Dong, Xiangdong; Bi, Xinhong; Mei, Heili; Li, Julin; He, Weilan; Lu, Yunlai; Ma, Hongli; Wen, Xiuqiong; Huang, Mei; Wright, David J.; King, Melissa; High, Patrick; Nelson, Kenrad; Shan, Hua

2010-01-01

Background It is important to understand donor return behavior. Converting first time donors to become repeat donors is essential for maintaining an adequate blood supply. Methods Characteristics of 241,552 whole blood (WB) donations from first time (FT) and repeat (RPT) donors who donated in 2008 at the 5 blood centers in China were compared. A subset of 54,394 WB donors who donated between January 1 and March 31, 2008 were analyzed for their return behavior in 2008 following the index donation using logistic regression. Results Of all donations, 64% was from FT donors. Donors with self-reported previous donations tended to be male, older, married, donated larger volume (≥300mL), and were heavier in weight. Among donors who donated from January to March, 2008, 14% returned for subsequent WB donations by the end of 2008. The number of previous donations and blood collection location were the two strongest predictors for making subsequent donations. Donors with 1, 2–3 and more than 3 previous donations were 3.7, 5.7, and 11.0 times more likely to return than FT donors. Those who donated in a blood collection vehicle were 4 times more likely to return than those who donated at a blood center. Being female, younger and of a lower education level (≤ middle school) were positively associated with subsequent return blood donation during the follow-up period observed in this study. Conclusion Most of the Chinese blood supply is from first time donors. Strategies aimed at encouraging current donors to become repeat donors are needed. PMID:20849408

Silent Brain Infarction and Risk of Future Stroke: A Systematic Review and Meta-Analysis

PubMed Central

Gupta, Ajay; Giambrone, Ashley E.; Gialdini, Gino; Finn, Caitlin; Delgado, Diana; Gutierrez, Jose; Wright, Clinton; Beiser, Alexa S.; Seshadri, Sudha; Pandya, Ankur; Kamel, Hooman

2016-01-01

Background and Purpose Silent brain infarction (SBI) on magnetic resonance imaging (MRI) has been proposed as a subclinical risk marker for future symptomatic stroke. We performed a systematic review and meta-analysis to summarize the association between MRI-defined SBI and future stroke risk. Methods We searched the medical literature to identify cohort studies involving adults with MRI detection of SBI who were subsequently followed for incident clinically-defined stroke. Study data and quality assessment were recorded in duplicate with disagreements in data extraction resolved by a third reader. Strength association between MRI detected SBI and future symptomatic stroke measured by a hazard ratio (HR). Results The meta-analysis included 13 studies (14,764 subjects) with a mean follow-up ranging from 25.7 to 174 months. SBI predicted the occurrence of stroke with a random effects crude relative risk of 2.94 (95% CI 2.24–3.86, P<0.001; Q=39.65, P<0.001). In the eight studies of 10,427 subjects providing HR adjusted for cardiovascular risk factors, SBI was an independent predictor of incident stroke (HR 2.08 [95% CI 1.69–2.56, P<0.001]; Q=8.99, P=0.25). In a subgroup analysis pooling 9,483 stroke-free individuals from large population-based studies, SBI was present in ~18% of participants and remained a strong predictor of future stroke (HR 2.06 [95% CI 1.64–2.59], p<0.01). Conclusions SBI is present in approximately one in five stroke-free older adults and is associated with a 2-fold increased risk of future stroke. Future studies of in-depth stroke risk evaluations and intensive prevention measures are warranted in patients with clinically unrecognized radiologically evident brain infarctions. PMID:26888534

Cognitive-communication disorder following right hemisphere stroke: exploring rehabilitation access and outcomes.

PubMed

Hewetson, Ronelle; Cornwell, Petrea; Shum, David

2017-07-01

Rehabilitation positively influences return to activities and social roles in people with aphasia. The cognitive-communication disorder (CCD) found following a right hemisphere stroke has been less extensively researched with rehabilitation access and outcomes yet to be determined. To document rehabilitation access and outcomes for people with CCD post-stroke; and compare outcomes based on presence (viz CCD; aphasia) or absence of communication impairment. A retrospective chart audit was completed for patients with first onset unilateral stroke, with a hospital length of stay (LOS) of at least two days and a communication assessment by a speech pathologist. Data extracted included presence and severity of communication impairment, access to and LOS in a rehabilitation unit, and functional outcome measures recorded at rehabilitation discharge. The majority of the 115 patients who met inclusion criteria were living independently (n = 112, 97.4%) at the time of stroke. CCD (66%) was diagnosed with similar frequency to aphasia (68%). The presence of communication impairment did not result in significant differences in rehabilitation LOS and discharge destination when compared to hemispheric strokes without communication impairment. Severity of CCD was an independent predictor of functional gain by rehabilitation discharge. People with CCD require comparable access to rehabilitation as people with aphasia, and severity of CCD should be considered in determining rehabilitation LOS. A large number of people are discharged with ongoing CCD which warrants exploration of potential participation restrictions created by the communication impairment.

Statistical analysis of lightning electric field measured under Malaysian condition

NASA Astrophysics Data System (ADS)

Salimi, Behnam; Mehranzamir, Kamyar; Abdul-Malek, Zulkurnain

2014-02-01

Lightning is an electrical discharge during thunderstorms that can be either within clouds (Inter-Cloud), or between clouds and ground (Cloud-Ground). The Lightning characteristics and their statistical information are the foundation for the design of lightning protection system as well as for the calculation of lightning radiated fields. Nowadays, there are various techniques to detect lightning signals and to determine various parameters produced by a lightning flash. Each technique provides its own claimed performances. In this paper, the characteristics of captured broadband electric fields generated by cloud-to-ground lightning discharges in South of Malaysia are analyzed. A total of 130 cloud-to-ground lightning flashes from 3 separate thunderstorm events (each event lasts for about 4-5 hours) were examined. Statistical analyses of the following signal parameters were presented: preliminary breakdown pulse train time duration, time interval between preliminary breakdowns and return stroke, multiplicity of stroke, and percentages of single stroke only. The BIL model is also introduced to characterize the lightning signature patterns. Observations on the statistical analyses show that about 79% of lightning signals fit well with the BIL model. The maximum and minimum of preliminary breakdown time duration of the observed lightning signals are 84 ms and 560 us, respectively. The findings of the statistical results show that 7.6% of the flashes were single stroke flashes, and the maximum number of strokes recorded was 14 multiple strokes per flash. A preliminary breakdown signature in more than 95% of the flashes can be identified.

Stroke outcomes in Northern Scotland: does rurality really matter?

PubMed

O'Neill, N P; Godden, D J

2003-01-01

Stroke is the third leading cause of death in Scotland after coronary heart disease and cancer and is a major cause of long-term disability. There is evidence in other clinical conditions such as asthma, diabetic retinopathy, and cancer that rural residents may have poorer outcomes, due to relative inaccessibility of health-service provision or because the disease is at a more advanced stage at diagnosis. However, the evidence-base for stroke care and outcomes in remote and rural areas is small and the subject matter is under-researched. This study was designed to examine, over a one-year period, the incidence and outcome of stroke occurring in the Highlands and Islands of Scotland, a large geographical area with many rural and remote settlements. The study explored whether stroke care and outcome was affected by remoteness and rurality. The study was a prospective, community-based, observational survey. Patients in Highland and the Islands (Orkney, Shetland and the Western Isles) suffering first-ever stroke during a 12-month period (from 1 May 2001 to 30 April 2002) were included. All practitioners from health and social care sectors, residential homes, voluntary and charitable organisations were encouraged to notify the researchers of any individual they suspected or knew had a first-ever stroke within the designated time period. Data on 'limitation in activities' (formerly 'level of disability') and service provision were collected using questionnaires and proformas at 1, 3 and 6 months post-stroke from several sources. These included individual patients and carers, health and social care professionals, residential homes, voluntary organisations, and charitable organisations. The analysis focused on location at time of follow up, limitation in activities and service provision. Outcomes were compared across different settlement categories. Settlements were classified as urban/accessible, remote rural and very remote, based on the Scottish Household Survey. In all, 303 patients with a suspected first-ever stroke were notified to the study. The resulting crude incidence of reported stroke was 1.1 per 1000. From the notifications, 239 patients were sent a consent form, of whom 118 agreed to participate in the study. The final dataset, after exclusions for incorrect diagnosis, deaths and other reasons, was derived from 85 patients. Among these, patients from remote rural and very remote settlements were over-represented, when compared to all patients notified. The majority of patients returned home from acute hospitals during the study period and the likelihood of returning home was not related to settlement category. However, a greater proportion of patients in remote rural settlements were admitted to community hospitals and remained there at 6 months. Approximately two-thirds had some degree of disability (or limitation in activities) after their stroke. One-third of patients classed themselves as independent across all time points. Overall, the Barthel Index score increased over time (ie, patients experienced a reduction in disability) with the average score at 1 month post-stroke being 82.5 (range 0-100), at 3 months 85 (range 5-100), and at 6 months 90 (range 5-100). Uptake of services was similar across all settlement categories, with low levels of use at 6-months post-stroke. In particular, few patients used social-support and stroke-specific services, for example Chest, Heart and Stroke Scotland, and Stroke Nurse services. The proportion of patients using any service at 1, 3 and 6 months did not differ between settlement categories. Rural patients did not therefore appear disadvantaged in service provision. The low incidence of reported stroke may have been due to a number of reasons including: death prior to notification; diagnostic uncertainty; stroke severity--failure to notify very mild or very severe stroke cases; and inadequate reporting of patients managed at home. The greater proportion of patients in remote rural settlements being admitted to community hospitals and remaining there at 6 months may reflect greater availability of community hospital places in this settlement category, but may also be influenced by stroke severity. The low uptake of rehabilitation and support services generally, combined with the relatively poor functional outcome of our patients, suggests that there may be an unmet need for rehabilitation. However, rural patients did not appear specifically disadvantaged. Our study indicates that patients developing a first-time stroke in remote and rural areas of the Highlands and Islands of Scotland are not disadvantaged compared to those in urban/accessible areas, with respect to outcome or to the utilization of health and social care services. However, functional outcomes could be improved for patients in all settlement categories.

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.

Tocotrienol vitamin E protects against preclinical canine ischemic stroke by inducing arteriogenesis.

PubMed

Rink, Cameron; Christoforidis, Greg; Khanna, Savita; Peterson, Laura; Patel, Yojan; Khanna, Suchin; Abduljalil, Amir; Irfanoglu, Okan; Machiraju, Raghu; Bergdall, Valerie K; Sen, Chandan K

2011-11-01

Vitamin E consists of tocopherols and tocotrienols, in which α-tocotrienol is the most potent neuroprotective form that is also effective in protecting against stroke in rodents. As neuroprotective agents alone are insufficient to protect against stroke, we sought to test the effects of tocotrienol on the cerebrovascular circulation during ischemic stroke using a preclinical model that enables fluoroscopy-guided angiography. Mongrel canines (mean weight=26.3±3.2 kg) were supplemented with tocotrienol-enriched (TE) supplement (200 mg b.i.d, n=11) or vehicle placebo (n=9) for 10 weeks before inducing transient middle cerebral artery (MCA) occlusion. Magnetic resonance imaging was performed 1 hour and 24 hours post reperfusion to assess stroke-induced lesion volume. Tocotrienol-enriched supplementation significantly attenuated ischemic stroke-induced lesion volume (P<0.005). Furthermore, TE prevented loss of white matter fiber tract connectivity after stroke as evident by probabilistic tractography. Post hoc analysis of cerebral angiograms during MCA occlusion revealed that TE-supplemented canines had improved cerebrovascular collateral circulation to the ischemic MCA territory (P<0.05). Tocotrienol-enriched supplementation induced arteriogenic tissue inhibitor of metalloprotease 1 and subsequently attenuated the activity of matrix metalloproteinase-2. Outcomes of the current preclinical trial set the stage for a clinical trial testing the effects of TE in patients who have suffered from transient ischemic attack and are therefore at a high risk for stroke.

Recent advances in the management of transient ischemic attacks

PubMed Central

Gomez, Camilo R.; Schneck, Michael J.; Biller, Jose

2017-01-01

Significant advances in our understanding of transient ischemic attack (TIA) have taken place since it was first recognized as a major risk factor for stroke during the late 1950's. Recently, numerous studies have consistently shown that patients who have experienced a TIA constitute a heterogeneous population, with multiple causative factors as well as an average 5–10% risk of suffering a stroke during the 30 days that follow the index event. These two attributes have driven the most important changes in the management of TIA patients over the last decade, with particular attention paid to effective stroke risk stratification, efficient and comprehensive diagnostic assessment, and a sound therapeutic approach, destined to reduce the risk of subsequent ischemic stroke. This review is an outline of these changes, including a discussion of their advantages and disadvantages, and references to how new trends are likely to influence the future care of these patients. PMID:29263784

Thrombolysis for stroke in pregnancy at 39 weeks gestation with a subsequent normal delivery.

PubMed

Ritchie, Joanne; Lokman, Mariam; Panikkar, Jane

2015-08-11

Stroke during pregnancy is fortunately a rare event, however, it can have severe consequences, with 9.5% of all maternal deaths being related to stroke. The most common presentation is an ischaemic stroke. There has been much debate as to the correct treatment for such cases' and whether thrombolysis can be used safely in pregnancy. Our case describes a 28-year-old woman with a previous normal vaginal delivery presenting in her third trimester with a sudden onset of dense left hemiparesis. She was successfully treated with alteplase, an intravenous recombinant tissue-type plasminogen activator, and made a full recovery after normal delivery of a healthy infant. This case report highlights one of the first documented successful outcomes from thrombolysis for this condition in the UK and may help inform future management of these women. 2015 BMJ Publishing Group Ltd.

Recovery from exercise at varying work loads - Time course of responses of heart rate and systolic intervals

NASA Technical Reports Server (NTRS)

Nandi, P. S.; Spodick, D. H.

1977-01-01

The time course of the recovery period was characterized by noninvasive measurements after 4 minute bicycle exercise at 3 separate work loads in volunteers with normal peak responses. Most responses started immediately to return toward resting control values. Left ventricular ejection time and stroke volume change are discussed. Changes in pre-ejection period were determined by changes in isovolume contraction time, and factors affecting the degree and rate of return are considered. The rates of change in the ejection time index and in the ratio pre-ejection period/left ventricular ejection time were virtually independent of load throughout most of recovery.

Treatment targets for M2 microglia polarization in ischemic stroke.

PubMed

Wang, Ji; Xing, Hongyi; Wan, Lin; Jiang, Xingjun; Wang, Chen; Wu, Yan

2018-06-05

As the first line of defense in the nervous system, resident microglia are the predominant immune cells in the brain. In diseases of the central nervous system such as stroke, Alzheimer's disease, and Parkinson's disease, they often cause inflammation or phagocytosis; however, some studies have found that despite the current controversy over M1, M2 polarization could be beneficial. Ischemic stroke is the third most common cause of death in humans. Patients who survive an ischemic stroke might experience a clear decline in their quality of life, owing to conditions such as hemiplegic paralysis and aphasia. After stroke, the activated microglia become a double-edged sword, with distinct phenotypic changes to the deleterious M1 and neuroprotective M2 types. Therefore, methods for promoting the differentiation of microglia into the M2 polarized form to alleviate harmful reactions after stroke have become a topic of interest in recent years. Subsequently, the discovery of new drugs related to M2 polarization has enabled the realization of targeted therapies. In the present review, we discussed the neuroprotective effects of microglia M2 polarization and the potential mechanisms and drugs by which microglia can be transformed into the M2 polarized type after stroke. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

MRI characteristics of carotid bulb atypical fibromuscular dysplasia in black stroke patients.

PubMed

Joux, Julien; Mejdoubi, Mehdi; Quere, Jean-Baptiste; Colombani, Sylvie; Hennequin, Jean-Luc; Deschamps, Lydia; Jeannin, Séverine; Olindo, Stéphane

2016-06-01

In black stroke patients, a particular form of fibromuscular dysplasia (FMD), called atypical FMD (aFMD), is involved in stroke mechanism. The high rate of stroke recurrence under medical treatment leads to propose surgery in such patients. Regarding its location level on the carotid bulb, aFMD is often confused with atherosclerosis or free-floating thrombus. Nowadays, only histology can confirm the diagnosis. MRI of aFMD has never been assessed. The constitution of a black patient's cohort with aFMD-related ischemic stroke is currently in progress in the French West Indies, Martinique. In patients scheduled for surgery, MRI of the carotid bifurcation was analyzed preoperatively, with subsequent histological examination of the excised specimen. The first four black stroke patients with MRI and histological findings are described. On imaging, aFMD lesion was homogeneous with isosignal on T2-weighted sequences and slight hypersignal on T1-weighted sequences with mild gadolinium enhancement of the inner layer. Histological findings confirmed the aFMD mainly located in the intima. aFMD generates a particular MRI pattern in our four patients, which could increase the diagnosis accuracy. Carotid bulb lesion in black stroke patients should suggest aFMD and MRI analysis may contribute to rule out differential diagnoses. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

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.

Thrombectomy for ischemic stroke: meta-analyses of recurrent strokes, vasospasms, and subarachnoid hemorrhages.

PubMed

Emprechtinger, Robert; Piso, Brigitte; Ringleb, Peter A

2017-03-01

Mechanical thrombectomy with stent retrievers is an effective treatment for patients with ischemic stroke. Results of recent meta-analyses report that the treatment is safe. However, the endpoints recurrent stroke, vasospasms, and subarachnoid hemorrhage have not been evaluated sufficiently. Hence, we extracted data on these outcomes from the five recent thrombectomy trials (MR CLEAN, ESCAPE, REVASCAT, SWIFT PRIME, and EXTEND IA published in 2015). Subsequently, we conducted meta-analyses for each outcome. We report the results of the fixed, as well as the random effects model. Three studies reported data on recurrent strokes. While the results did not reach statistical significance in the random effects model (despite a three times elevated risk), the fixed effects model revealed a significantly higher rate of recurrent strokes after thrombectomy. Four studies reported data on subarachnoid hemorrhage. The higher pooled rates in the intervention groups were statistically significant in both, the fixed and the random effects model. One study reported on vasospasms. We recorded 14 events in the intervention group and none in the control group. The efficacy of mechanical thrombectomy is not questioned, yet our results indicate an increased risk for recurrent strokes, subarachnoid hemorrhage, and vasospasms post-treatment. Therefore, we strongly recommend a thoroughly surveillance, concerning these adverse events in future clinical trials and routine registries.

Quality of life after stroke: the North East Melbourne Stroke Incidence Study (NEMESIS).

PubMed

Sturm, Jonathan W; Donnan, Geoffrey A; Dewey, Helen M; Macdonell, Richard A L; Gilligan, Amanda K; Srikanth, Velandai; Thrift, Amanda G

2004-10-01

Health-related quality of life (HRQoL) data are scarce from unselected populations. The aims were to assess HRQoL at 2 years poststroke, to identify determinants of HRQoL in stroke survivors, and to identify predictors at stroke onset of subsequent HRQoL. All first-ever cases of stroke in a population of 306 631 over a 1-year period were assessed. Stroke severity, comorbidity, and demographic information were recorded. Two-year poststroke HRQoL was assessed using the Assessment of Quality of Life (AQoL) instrument (deceased patients score=0). Handicap, disability, physical impairment, depression, anxiety, living arrangements, and recurrent stroke at 2 years were documented. If necessary, proxy assessments were obtained, except for mood. Linear regression analyses were performed to identify factors independently associated with HRQoL. Of 266 incident cases alive at 2 years, 225 (85%) were assessed. The mean AQoL utility score for all survivors was 0.47 (95% CI, 0.42 to 0.52). Almost 25% of survivors had a score of < or =0.1. The independent determinants of HRQoL in survivors were handicap, physical impairment, anxiety and depression, disability, institutionalization, dementia, and age. The factors present at stroke onset that independently predicted HRQoL at 2 years poststroke were age, female sex, initial NIHSS score, neglect, and low socioeconomic status. A substantial proportion of stroke survivors have very poor HRQoL. Interventions targeting handicap and mood have the potential to improve HRQoL independently of physical impairment and disability.

Modeling Stroke in Mice: Permanent Coagulation of the Distal Middle Cerebral Artery

PubMed Central

Plesnila, Nikolaus; Veltkamp, Roland; Liesz, Arthur

2014-01-01

Stroke is the third most common cause of death and a main cause of acquired adult disability in developed countries. Only very limited therapeutical options are available for a small proportion of stroke patients in the acute phase. Current research is intensively searching for novel therapeutic strategies and is increasingly focusing on the sub-acute and chronic phase after stroke because more patients might be eligible for therapeutic interventions in a prolonged time window. These delayed mechanisms include important pathophysiological pathways such as post-stroke inflammation, angiogenesis, neuronal plasticity and regeneration. In order to analyze these mechanisms and to subsequently evaluate novel drug targets, experimental stroke models with clinical relevance, low mortality and high reproducibility are sought after. Moreover, mice are the smallest mammals in which a focal stroke lesion can be induced and for which a broad spectrum of transgenic models are available. Therefore, we describe here the mouse model of transcranial, permanent coagulation of the middle cerebral artery via electrocoagulation distal of the lenticulostriatal arteries, the so-called “coagulation model”. The resulting infarct in this model is located mainly in the cortex; the relative infarct volume in relation to brain size corresponds to the majority of human strokes. Moreover, the model fulfills the above-mentioned criteria of reproducibility and low mortality. In this video we demonstrate the surgical methods of stroke induction in the “coagulation model” and report histological and functional analysis tools. PMID:25145316

Pathophysiologic correlates of thromboembolism in nonvalvular atrial fibrillation: I. Reduced flow velocity in the left atrial appendage (The Stroke Prevention in Atrial Fibrillation [SPAF-III] study).

PubMed

Goldman, M E; Pearce, L A; Hart, R G; Zabalgoitia, M; Asinger, R W; Safford, R; Halperin, J L

1999-12-01

Stroke associated with atrial fibrillation (AF) is mainly due to embolism of thrombus formed during stasis of blood in the left atrial appendage (LAA). Pathophysiologic correlates of appendage flow velocity as assessed by transesophageal echocardiography (TEE) in patients with AF have not been defined. To evaluate the hypothesis that reduced velocity is associated with spontaneous echocardiographic contrast and thrombus in the LAA and with clinical embolic events, we measured LAA flow velocity by TEE in 721 patients with nonvalvular AF entering the Stroke Prevention in Atrial Fibrillation (SPAF-III) study. Patient features, TEE findings, and subsequent cardioembolic events were correlated with velocity by multivariate analysis. Patients in AF during TEE displayed lower peak antegrade (emptying) flow velocity (Anu(p)) than those with intermittent AF in sinus rhythm during TEE (33 cm/s vs 61 cm/s, respectively, P <.0001). Anu(p) < 20 cm/s was associated with dense spontaneous echocardiographic contrast (P <.001), appendage thrombus (P <.01), and subsequent cardioembolic events (P <.01). Independent predictors of Anu(p) < 20 cm/s included age (P =.009), systolic blood pressure (P <.001), sustained AF (P =.01), ischemic heart disease (P =.01), and left atrial area (P =.04). Multivariate analysis found both Anu(p) <20 cm/s (relative risk 2.6, P =.02) and clinical risk factors (relative risk 3.3, P =.002) independently associated with LAA thrombus. LAA Anu(p) is reduced in AF and associated with spontaneous echocardiographic contrast, appendage thrombus, and cardioembolic stroke. Systolic hypertension and aortic atherosclerosis, independent clinical predictors of stroke in patients with AF, also correlated with LAA Anu(p). Our results support the role of reduced LAA Anu(p) in the generation of stasis, thrombus formation, and embolism in patients with AF, although other mechanisms also contribute to stroke.

Facilitating Successful Re-Entries in the United States: Training and Development for Women Returners

ERIC Educational Resources Information Center

Greer, Tomika W.

2013-01-01

Women returners are women who leave the paid workforce for a period of time following the birth of their child(ren) and subsequently seek to return to paid employment. As women returners attempt to re-enter the workforce, many of them are in need of updating their skills or re-training in a new set of skills. In this study, the training and…

Is there an ideal way to initiate antiplatelet therapy with aspirin? A crossover study on healthy volunteers evaluating different dosing schemes with whole blood aggregometry

PubMed Central

2011-01-01

Background Guidelines recommend an early initiation of aspirin treatment in patients with acute cerebral ischemia. Comparative studies on the best starting dose for initiating aspirin therapy to achieve a rapid antiplatelet effect do not exist. This study evaluated the platelet inhibitory effect in healthy volunteers by using three different aspirin loading doses to gain a model for initiating antiplatelet treatment in acute strokes patients. Methods Using whole blood aggregometry, this study with a prospective, uncontrolled, open, crossover design examined 12 healthy volunteers treated with three different aspirin loading doses: intravenous 500 mg aspirin, oral 500 mg aspirin, and a course of 200 mg aspirin on two subsequent days followed by a five-day course of 100 mg aspirin. Aspirin low response was defined as change of impedance exceeding 0 Ω after stimulation with arachidonic acid. Results Sufficient antiplatelet effectiveness was gained within 30 seconds when intravenous 500 mg aspirin was used. The mean time until antiplatelet effect was 74 minutes for 500 mg aspirin taken orally and 662 minutes (11.2 hours) for the dose scheme with 200 mg aspirin with a high inter- and intraindividual variability in those two regimes. Platelet aggregation returned to the baseline range during the wash-out phase within 4 days. Conclusion Our study reveals that the antiplatelet effect differs significantly between the three different aspirin starting dosages with a high inter- and intraindividual variability of antiplatelet response in our healthy volunteers. To ensure an early platelet inhibitory effect in acute stroke patients, it could be advantageous to initiate the therapy with an intravenous loading dose of 500 mg aspirin. However, clinical outcome studies must still define the best way to initiate antiplatelet treatment with aspirin. PMID:21466682

Physical health-related quality of life predicts stroke in the EPIC-Norfolk.

PubMed

Myint, P K; Surtees, P G; Wainwright, N W J; Luben, R N; Welch, A A; Bingham, S A; Wareham, N J; Khaw, K-T

2007-12-11

To examine the relationship between Short Form (SF)-36 physical functional health-related quality of life and incident stroke. A total of 13,615 men and women participating in the European Prospective Investigation into Cancer-Norfolk who were free of stroke, myocardial infarction, and cancer at baseline were included in the study. Participants completed a health and lifestyle questionnaire and attended a health examination during 1993 to 1997. Self-reported physical functional health was assessed using physical component summary scores of SF-36 18 months later. Stroke incidence was ascertained by death certification and hospital record linkage up to 2005. There were 244 incident strokes (total person years = 99,191). People who reported better physical functional health had significantly lower risk of incident stroke. Using Cox proportional hazard models adjusting for age, sex, body mass index, systolic blood pressure, cholesterol, smoking, diabetes, physical activity, social class, alcohol consumption, and respiratory function, men and women who were in the top quartile of SF-36 physical component summary scores had half the risk of stroke (RR = 0.50 [0.31, 0.78]) compared to the people in the bottom quartile. The relationships remained unchanged after excluding strokes occurring within the first 2 years of follow-up. Physical functional health-related quality of life measured as Short Form-36 predicts subsequent stroke risk independently of known risk factors in a general population. Poor physical functional health may indicate a high-risk population for stroke who may benefit most from targeted preventive interventions such as management of known risk factors.

Yield of ultra-rapid carotid ultrasound and stroke specialist assessment in patients with TIA and minor stroke: an Italian TIA service audit.

PubMed

Gulli, Giosuè; Peron, Elisa; Ricci, Giorgio; Formaglio, Eva; Micheletti, Nicola; Tomelleri, Giampaolo; Moretto, Giuseppe

2014-12-01

In Italy the vast majority of TIA and minor strokes are seen in the A&E. Early diagnosis and management of TIA and minor stroke in this setting is habitually difficult and often lead to cost-ineffective hospital admissions. We set up an ultra-rapid TIA service run by neurovascular physicians based on early specialist assessment and ultrasound vascular imaging. We audit the clinical effectiveness and feasibility of the service and the impact of this service on TIA and minor strokes hospital admissions. We compared the rate of TIA and minor stroke admissions/discharges in the year before (T0) and in the year during which the TIA service was operating (T1). At T1 57 patients had specialist evaluation and 51 (89.5 %) of them were discharged home. Two (3.5 %) patients had recurrent symptoms after discharge. Seven had a pathological carotid Doppler ultrasound. Four of them had hospital admission and subsequent carotid endoarterectomy within a week. Taking the whole neurology department into consideration at T1 there was a 30-41 % reduction in discharges of patients with TIA or minor stroke. Taking the stroke unit section into consideration at T1 there was a 25 % reduction in admissions of patients with NIHSS score <4 and 40 % reduction in admissions of patients with Barthel Index above 80. The model of TIA service we implemented based on ultra-rapid stroke physician assessment and carotid ultrasound investigation is feasible and clinically valid. Indirect evidence suggests that it reduced the rate of expensive TIA/minor stroke hospital admissions.

Study of Stroke Incidence in the Aseer Region, Southwestern Saudi Arabia.

PubMed

Alhazzani, Adel A; Mahfouz, Ahmed A; Abolyazid, Ahmed Y; Awadalla, Nabil J; Aftab, Razia; Faraheen, Aesha; Khalil, Shamsun Nahar

2018-01-26

Recent data regarding first-stroke incidence in Saudi Arabia in general and in the Aseer region in particular are scarce and even lacking. The aim of this work was to study the first-time stroke incidence in the Aseer region, southwestern Saudi Arabia. All first-stroke patients admitted to all hospitals in the Aseer region over a one-year period (January through December 2016) were included. Stroke patients outside the Aseer region were excluded from the study. The incidence per 100,000 patients and the concomitant 95% CI (Confidence Intervals) were computed. The present study included 1249 first-time stroke patients and calculated an overall minimal incidence rate of hospitalized first-time stroke of 57.64 per 100,000 persons per year (95% CI: 57.57-57.70). A steady increase was noticed depending on the patients' age, reaching a figure of 851.81 (95% CI: 849.2-854.5) for those patients aged 70 years and more. Overall, the incidence rate for females (48.14; 95% CI: 48.04-48.24) was lower compared to males (65.52; 95% CI: 65.1-66.0). Taking into consideration the expected rise of the elderly because of the prominent medical services provided by the Saudi government, leading to a subsequent change in the horizontal and vertical age distribution structure of the population, an increase in the number of stroke patients is expected. It is suggested to establish a nationwide stroke surveillance system in the Kingdom, with the objective to report, analyze, and maintain an updated overview of the stroke status in Saudi Arabia.

Post-ischemic stroke rehabilitation is associated with a higher risk of fractures in older women: A population-based cohort study.

PubMed

Huang, Huei Kai; Lin, Shu Man; Yang, Clement Shih Hsien; Liang, Chung Chao; Cheng, Hung Yu

2017-01-01

Rehabilitation can improve physical activity after stroke. However, patients may be more prone to falls and fractures because of balance and gait deficits. Few reports have studied the relationship between rehabilitation and subsequent fractures after ischemic stroke. To investigate whether post-stroke rehabilitation affects fracture risk. We conducted a population-based retrospective cohort study based on the Taiwan National Health Insurance Research Database. Patients with a newly diagnosed ischemic stroke between 2000 and 2012 were included. After propensity score matching, a total of 8,384 patients were enrolled. Half of the patients (4,192) received post-stroke rehabilitation within 1 month; the other half did not receive any post-stroke rehabilitation. Cox proportional hazards regression model was used to calculate hazard ratios (HRs) for fractures among patients with and without rehabilitation within 1 year after ischemic stroke. Patients were further stratified by sex and age (20-64 and ≥65 years). Patients receiving post-stroke rehabilitation had a higher incidence of fracture (6.2 per 100 person-years) than those who did not (4.1 per 100 person-years) after adjustment for sociodemographic and coexisting medical conditions [HR = 1.53, 95% confidence interval (CI) = 1.25-1.87, p < 0.001]. The analyses performed after stratifying for sex and age showed that only older women undergoing rehabilitation had a significantly higher risk of fracture (HR = 1.62, 95% CI = 1.21-2.17, p = 0.001). Rehabilitation after ischemic stroke is associated with an increased fracture risk in older women.

Diagnostic value of prehospital ECG in acute stroke patients.

PubMed

Bobinger, Tobias; Kallmünzer, Bernd; Kopp, Markus; Kurka, Natalia; Arnold, Martin; Heider, Stefan; Schwab, Stefan; Köhrmann, Martin

2017-05-16

To investigate the diagnostic yield of prehospital ECG monitoring provided by emergency medical services in the case of suspected stroke. Consecutive patients with acute stroke admitted to our tertiary stroke center via emergency medical services and with available prehospital ECG were prospectively included during a 12-month study period. We assessed prehospital ECG recordings and compared the results to regular 12-lead ECG on admission and after continuous ECG monitoring at the stroke unit. Overall, 259 patients with prehospital ECG recording were included in the study (90.3% ischemic stroke, 9.7% intracerebral hemorrhage). Atrial fibrillation (AF) was detected in 25.1% of patients, second-degree or greater atrioventricular block in 5.4%, significant ST-segment elevation in 5.0%, and ventricular ectopy in 9.7%. In 18 patients, a diagnosis of new-onset AF with direct clinical consequences for the evaluation and secondary prevention of stroke was established by the prehospital recordings. In 2 patients, the AF episodes were limited to the prehospital period and were not detected by ECG on admission or during subsequent monitoring at the stroke unit. Of 126 patients (48.6%) with relevant abnormalities in the prehospital ECG, 16.7% received medical antiarrhythmic therapy during transport to the hospital, and 6.4% were transferred to a cardiology unit within the first 24 hours in the hospital. In a selected cohort of patients with stroke, the in-field recordings of the ECG detected a relevant rate of cardiac arrhythmia. The results can add to the in-hospital evaluation and should be considered in prehospital care of acute stroke. © 2017 American Academy of Neurology.

Vascular cognitive disorders and depression after first-ever stroke: the Fogarty-Mexico Stroke Cohort.

PubMed

Arauz, Antonio; Rodríguez-Agudelo, Yaneth; Sosa, Ana Luisa; Chávez, Mireya; Paz, Francisco; González, Margarita; Coral, Juliana; Díaz-Olavarrieta, Claudia; Román, Gustavo C

2014-01-01

Stroke is the major cause of vascular behavior and cognitive disorders worldwide. In developing countries, there is a dearth of information regarding the public health magnitude of stroke. The aim of the Fogarty-Mexico cohort was to assess the prevalence of vascular behavioral and cognitive disorders, ranging from mild vascular cognitive impairment (VCI) to vascular dementia (VaD), in a cohort of acute first-ever symptomatic stroke patients in Mexico. A total of 165 consecutive, first-ever stroke patients admitted to the National Institute of Neurology and Neurosurgery in Mexico City, were included in the cohort. Patients were eligible if they had an ischemic stroke, primary intracerebral hemorrhage, or cerebral venous thrombosis (CVT). Stroke diagnosis required the presence of an acute focal deficit lasting more than 24 h, confirmed by a corresponding lesion on CT/MRI. Stroke severity was established with the NIH Stroke Scale. The pre-stroke functional status was determined by the IQCODE. Three months after the occurrence of stroke, 110 survivor patients returned for follow-up and were able to undergo functional outcome (modified Rankin scale, Barthel index), along with neurological, psychiatric, neuropsychological, laboratory, and imaging assessments. We compared depression, demographic, and clinical and imaging features between patients with and without dementia, and between patients with VCI and those with intact cognition. Of the 110 patients (62% men, mean age 56 ± 17.8, education 7.7 ± 5.2 years) 93 (84%) had ischemic strokes, 14 (13%) intracerebral hemorrhage, and 3 (3%) CVT. The main risk factors were hypertension (50%), smoking (40%), hypercholesterolemia (29%), hyperhomocysteinemia (24%), and diabetes (22%). Clinical and neuropsychological evaluations demonstrated post-stroke depression in 56%, VCI in 41%, and VaD in 12%; 17% of the latter had pre-stroke functional impairment (IQCODE >3.5). Cognitive deficits included executive function in 69%, verbal memory in 49%, language in 38%, perception in 36%, and attention in 38%. Executive dysfunction occurred in 36% of non-demented subjects, 65% of them with mild-moderate deficits in daily living activities. Female gender (p ≤ 0.054), older age (mean age 65.6 years vs. 49.3, p < 0.001), diabetes (p ≤ 0.004), illiteracy and lower education (p ≤ 0.001), and PSD (p = 0.03) were significantly higher in VCI-VaD compared with cognitively intact post-stroke subjects. We could not demonstrate an association with lesion site and distribution of the cognitive deficits. The Fogarty-Mexico cohort recruited relatively young acute stroke patients, compared with other Mexican stroke cohorts. PSD and VCI occurred frequently but prevalence of VaD (12%) was lower than expected. A high prevalence of treatable stroke risk factors suggests that preventive interventions are advisable. © 2014 S. Karger AG, Basel.

Changes in cardiac output and tibial artery flow during and after progressive LBNP

NASA Technical Reports Server (NTRS)

1980-01-01

A 3.0 MHz Pulsed Doppler velocity meter (PD) was used to determine blood velocities in the ascending aorta from the suprasternal notch before, during and after progressive 5 min stages of lower body negative pressure (LBNP) in 7 subjects. Changes in stroke volume were calculated from the systolic velocity integrals. A unique 20 MHz PD was used to estimate bloodflow in the posterior tibial artery. With -20 torr mean stroke volume fell 11% and then continued to decline by 48% before LBNP was terminated. Mean tibial flow fell progressively with LBNP stress, due to an increase in reverse flow component and a reduction in peak forward flow and diameter. Stroke volume increased and heart rate fell dramatically during the first 15 sec of recovery. The LBNP was terminated early in 2 subjects because of vasovagal symptons (V). During V the stroke volume rose 86% which more than compensated for the drop in heart rate. This implies that V is accompanied by a paradoxical increase in venous return and that the reduction in HR is the primary cardiovascular event. During the first 15 sec of recovery these 2 subjects had a distinctive marked rise to heart rate reminiscent of the Bainbridge reflex.

A population-based study of disability and institutionalisation after TIA and stroke: 10-year results of the Oxford Vascular Study

PubMed Central

Luengo-Fernandez, Ramon; Paul, Nicola L.M.; Gray, Alastair M.; Pendlebury, Sarah T.; Bull, Linda M.; Welch, Sarah J.V.; Cuthbertson, Fiona C.; Rothwell, Peter M.

2016-01-01

Background and Purpose Long-term outcome information after TIA and stroke is required to help plan and allocate care services. We evaluated the impact of TIA and stroke on disability and institutionalisation over 5 years using data from a population-based study. Methods Patients from a UK population-based cohort study (Oxford Vascular Study) were recruited from 2002 to 2007, and followed-up to 2012. Patients were followed-up at 1, 6, 12, 24 and 60 months post-event and assessed using the modified Rankin Scale (mRS). A multivariate regression analysis was performed to assess the predictors of disability post-event. Results 748 index stroke and 440 TIA cases were studied. For TIA patients, disability levels increased from 14% (63/440) pre-morbidly to 23% (60/256) at 5 years (p=0.002), with occurrence of subsequent stroke being a major predictor of disability. For stroke survivors, the proportion disabled (mRS>2) increased from 21% (154/748) pre-morbidly to 43% (273/634) at 1-month (p<0.001), with 39% (132/339) of survivors disabled 5 years post-stroke. 5 years post-event, 70% (483/690) of stroke patients and 48% (179/375) of TIA patients were either dead or disabled. The 5-year risk of care home institutionalisation was 11% after TIA and 19% after stroke. The average 5-year cost per institutionalised TIA patient was $99,831 (S.D. 67,020) and $125,359 (S.D. 91,121) for stroke patients. Conclusions Our results show that 70% of stroke patients are either dead or disabled 5 years after the event. There therefore remains considerable scope for improvements in acute treatment and secondary prevention to reduce post-event disability and institutionalisation. PMID:23920019

[Results of thrombolyses procedures in acute ischemic cerebral stroke realized in Kraków 2004-2007--Grant Ministry of Science and Information].

PubMed

Popiela, Tadeusz J; Urbanik, Andrzej; Słowik, Agnieszka

2010-01-01

To lower the number of complications of acute cerebral ischemic stroke and to reduce the time of rehabilitation in these patients it is necessary to induce treatment within the first 3 hours of the onset of the stroke. Early intervention however, is possible only in cases with the confirm localized ischemic focus visualized in one of the diagnostic imaging methods. The most widespread is CT, hovewer the first symptoms of ischemic stroke can be seen not beforel2 hours of the onset. The study evaluated the effectiveness of early diagnostics of ischemic stroke using perfusion CT (pCT) with subsequent intravenous or intra-arterial thrombolysis. The patients with ischemic stroke confirmed by pCT and qualified to thrombolysis in the first 3 hours of the onset of the stroke were randomly selected to intravenous or intra-arterial thrmobolysis. Those, who were 3 to 6 hours of the onset of the stroke were qualified to intra-arterial thrombolysis. A study group consisted of 377 patients hospitalized due to ischemic stroke. Of these pCT was performed in 76 cases, intravenous thrombolysis in 4 and intra-arterial thrombolysis in 2. Clinical condition substantially improved in 3 patients. Obtained results indicate the necessity to introduce pCT to the routine diagnostics of the acute ischemic stroke. A small number of patients eligible for thrombolysis does not allow to compare the effectiveness of intra-arterial and intravenous thrombolysis, however the project allowed to work out the efficient system of diagnostics and treatment of the acute ischemic stroke in the area of Krakow based on the standards used in the European countries.

Early post-stroke cognition in stroke rehabilitation patients predicts functional outcome at 13 months.

PubMed

Wagle, Jørgen; Farner, Lasse; Flekkøy, Kjell; Bruun Wyller, Torgeir; Sandvik, Leiv; Fure, Brynjar; Stensrød, Brynhild; Engedal, Knut

2011-01-01

To identify prognostic factors associated with functional outcome at 13 months in a sample of stroke rehabilitation patients. Specifically, we hypothesized that cognitive functioning early after stroke would predict long-term functional outcome independently of other factors. 163 stroke rehabilitation patients underwent a structured neuropsychological examination 2-3 weeks after hospital admittance, and their functional status was subsequently evaluated 13 months later with the modified Rankin Scale (mRS) as outcome measure. Three predictive models were built using linear regression analyses: a biological model (sociodemographics, apolipoprotein E genotype, prestroke vascular factors, lesion characteristics and neurological stroke-related impairment); a functional model (pre- and early post-stroke cognitive functioning, personal and instrumental activities of daily living, ADL, and depressive symptoms), and a combined model (including significant variables, with p value <0.05, from the biological and functional models). A combined model of 4 variables best predicted long-term functional outcome with explained variance of 49%: neurological impairment (National Institute of Health Stroke Scale; β = 0.402, p < 0.001), age (β = 0.233, p = 0.001), post-stroke cognitive functioning (Repeatable Battery of Neuropsychological Status, RBANS; β = -0.248, p = 0.001) and prestroke personal ADL (Barthel Index; β = -0.217, p = 0.002). Further linear regression analyses of which RBANS indexes and subtests best predicted long-term functional outcome showed that Coding (β = -0.484, p < 0.001) and Figure Copy (β = -0.233, p = 0.002) raw scores at baseline explained 42% of the variance in mRS scores at follow-up. Early post-stroke cognitive functioning as measured by the RBANS is a significant and independent predictor of long-term functional post-stroke outcome. Copyright © 2011 S. Karger AG, Basel.

A clinical study of ischaemic strokes with micro-albuminuria for risk stratification, short-term predictive value and outcome.

PubMed

Das, Sukdeb; Yadav, Ujjal; Ghosh, Kartik Chandra; Panchadhyayee, Sujoy; Kundu, Shib Shankar; Ganguly, Prasanta Kumar

2012-12-01

Stroke results more than 4.3 million deaths worldwide per annum and 85% of all strokes are ischaemic in nature. Besides numerous modifiable and non-modifiable known risk factors, microalbuminuria is thought to be an important marker of global endothelial dysfunction and associated with cardiovascular disease including stroke. Fifty ischaemic stroke cases and 50 (age, sex matched) control subjects were subjected to study to compare and evaluate risk stratification of micro-albuminuria, its predictive value and outcome on day 1 and day 7 among admitted ischaemic stroke cases.The result was found that micro-albuminuria was present in 66% of ischaemic stroke cases compared to only 8% of control group (p < 0.001). Most validated National Institute of Health Stroke Scale (NIHSS) score was used for evaluation and calculation of predictive value and outcome of micro-albuminuria positive patient where higher value indicates poor prognosis, and the result was mean NIHSS score 29.12 versus 18.88 between two groups of strokes ie, with and without micro-albuminuria. Out of 50 ischaemic stroke patients 33 (66%) had micro-albuminuria. Among 11 patients who died, 10 (90.9%) had micro-albuminuria and NIHSS score was 33.64 and 25.0 on day 1 and day 7. Among 39 patients who were discharged, 23 patients (58.97%) were MA positive and NIHSS score was much less than death group ie, 23.38 and 16.38 on day 1 and day 7 respectively. So this study reveals micro-albuminuria itself results higher risk for ischaemic stroke compared to control group and it shows good predictive value for early assessment of clinical severity and subsequent fatal outcome. This is also simple, cost effective and affordable.

Shipborne LF-VLF oceanic lightning observations and modeling

NASA Astrophysics Data System (ADS)

Zoghzoghy, F. G.; Cohen, M. B.; Said, R. K.; Lehtinen, N. G.; Inan, U. S.

2015-10-01

Approximately 90% of natural lightning occurs over land, but recent observations, using Global Lightning Detection (GLD360) geolocation peak current estimates and satellite optical data, suggested that cloud-to-ground flashes are on average stronger over the ocean. We present initial statistics from a novel experiment using a Low Frequency (LF) magnetic field receiver system installed aboard the National Oceanic Atmospheric Agency (NOAA) Ronald W. Brown research vessel that allowed the detection of impulsive radio emissions from deep-oceanic discharges at short distances. Thousands of LF waveforms were recorded, facilitating the comparison of oceanic waveforms to their land counterparts. A computationally efficient electromagnetic radiation model that accounts for propagation over lossy and curved ground is constructed and compared with previously published models. We include the effects of Earth curvature on LF ground wave propagation and quantify the effects of channel-base current risetime, channel-base current falltime, and return stroke speed on the radiated LF waveforms observed at a given distance. We compare simulation results to data and conclude that previously reported larger GLD360 peak current estimates over the ocean are unlikely to fully result from differences in channel-base current risetime, falltime, or return stroke speed between ocean and land flashes.

FDTD Modeling of LEMP Propagation in the Earth-Ionosphere Waveguide With Emphasis on Realistic Representation of Lightning Source

NASA Astrophysics Data System (ADS)

Tran, Thang H.; Baba, Yoshihiro; Somu, Vijaya B.; Rakov, Vladimir A.

2017-12-01

The finite difference time domain (FDTD) method in the 2-D cylindrical coordinate system was used to compute the nearly full-frequency-bandwidth vertical electric field and azimuthal magnetic field waveforms produced on the ground surface by lightning return strokes. The lightning source was represented by the modified transmission-line model with linear current decay with height, which was implemented in the FDTD computations as an appropriate vertical phased-current-source array. The conductivity of atmosphere was assumed to increase exponentially with height, with different conductivity profiles being used for daytime and nighttime conditions. The fields were computed at distances ranging from 50 to 500 km. Sky waves (reflections from the ionosphere) were identified in computed waveforms and used for estimation of apparent ionospheric reflection heights. It was found that our model reproduces reasonably well the daytime electric field waveforms measured at different distances and simulated (using a more sophisticated propagation model) by Qin et al. (2017). Sensitivity of model predictions to changes in the parameters of atmospheric conductivity profile, as well as influences of the lightning source characteristics (current waveshape parameters, return-stroke speed, and channel length) and ground conductivity were examined.

A review of advances in lightning observations during the past decade in Guangdong, China

NASA Astrophysics Data System (ADS)

Zhang, Yijun; Lü, Weitao; Chen, Shaodong; Zheng, Dong; Zhang, Yang; Yan, Xu; Chen, Lüwen; Dong, Wansheng; Dan, Jianru; Pan, Hanbo

2016-08-01

This paper reviews recent advances in understanding the physical processes of artificially triggered lightning and natural lightning as well as the progress in testing lightning protection technologies, based on a series of lightning field campaigns jointly conducted by the Chinese Academy of Meteorological Sciences and Guangdong Meteorological Bureau since 2006. During the decade-long series of lightning field experiments, the technology of rocket-wire artificially triggered lightning has been improved, and has successfully triggered 94 lightning flashes. Through direct lightning current waveform measurements, an average return stroke peak current of 16 kA was obtained. The phenomenon that the downward leader connects to the lateral surface of the upward leader in the attachment process was discovered, and the speed of the upward leader during the connection process being significantly greater than that of the downward leader was revealed. The characteristics of several return strokes in cloud-to-ground lighting have also been unveiled, and the mechanism causing damage to lightning protection devices (i.e., ground potential rise within the rated current) was established. The performance of three lightning monitoring systems in Guangdong Province has also been quantitatively assessed.

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

Hemorrhagic and ischemic stroke secondary to herpes simplex virus type 2 meningitis and vasculopathy.

PubMed

Snider, Samuel B; Jacobs, Claire S; Scripko, Patricia S; Klein, Joshua P; Lyons, Jennifer L

2014-08-01

Herpes simplex virus type 2 (HSV-2) meningitis dogmatically is benign and self-limited in the immune competent patient. However, we describe how left untreated HSV-2 meningitis can be complicated by vasculitis and both ischemic and hemorrhagic stroke. We report a 57-year-old woman with lymphocytic meningitis complicated by ischemic stroke and intracerebral hemorrhage in the setting of vasculopathy and HSV-2 DNA detected in CSF successfully treated with acyclovir and corticosteroids. Subsequent angiographic magnetic resonance imaging revealed improvement in the vasculopathy after treatment. This case demonstrates that HSV-2 meningitis may take a less benign course and further provides the first evidence of angiographic improvement in addition to clinical improvement after definitive treatment.

Professional Rugby Union players have a 60% greater risk of time loss injury after concussion: a 2-season prospective study of clinical outcomes

PubMed Central

Cross, Matthew; Kemp, Simon; Smith, Andrew; Trewartha, Grant; Stokes, Keith

2016-01-01

Aim To investigate incidence of concussion, clinical outcomes and subsequent injury risk following concussion. Methods In a two-season (2012/2013, 2013/2014) prospective cohort study, incidence of diagnosed match concussions (injuries/1000 h), median time interval to subsequent injury of any type (survival time) and time spent at each stage of the graduated return to play pathway were determined in 810 professional Rugby Union players (1176 player seasons). Results Match concussion incidence was 8.9/1000 h with over 50% occurring in the tackle. Subsequent incidence of any injury for players who returned to play in the same season following a diagnosed concussion (122/1000 h, 95% CI 106 to 141) was 60% higher (IRR 1.6, 95% CI 1.4 to 1.8) than for those who did not sustain a concussion (76/1000 h, 95% CI 72 to 80). Median time to next injury following return to play was shorter following concussion (53 days, 95% CI 41 to 64) than following non-concussive injuries (114 days, 95% CI 85 to 143). 38% of players reported recurrence of symptoms or failed to match their baseline neurocognitive test during the graduated return to play protocol. Summary and conclusions Players who returned to play in the same season after a diagnosed concussion had a 60% greater risk of time-loss injury than players without concussion. A substantial proportion of players reported recurrence of symptoms or failed to match baseline neurocognitive test scores during graduated return to play. These data pave the way for trials of more conservative and comprehensive graduated return to play protocols, with a greater focus on active rehabilitation. PMID:26626266

Cross-sectional survey of workload and burnout among Japanese physicians working in stroke care: the nationwide survey of acute stroke care capacity for proper designation of comprehensive stroke center in Japan (J-ASPECT) study.

PubMed

Nishimura, Kunihiro; Nakamura, Fumiaki; Takegami, Misa; Fukuhara, Schunichi; Nakagawara, Jyoji; Ogasawara, Kuniaki; Ono, Junichi; Shiokawa, Yoshiaki; Miyachi, Shigeru; Nagata, Izumi; Toyoda, Kazunori; Matsuda, Shinya; Kataoka, Hiroharu; Miyamoto, Yoshihiro; Kitaoka, Kazuyo; Kada, Akiko; Iihara, Koji

2014-05-01

Burnout is common among physicians and affects the quality of care. We aimed to determine the prevalence of burnout among Japanese physicians working in stroke care and evaluate personal and professional characteristics associated with burnout. A cross-sectional design was used to develop and distribute a survey to 11 211 physicians. Physician burnout was assessed using the Maslach Burnout Inventory General Survey. The predictors of burnout and the relationships among them were identified by multivariable logistic regression analysis. A total of 2724 (25.3%) physicians returned the surveys. After excluding those who were not working in stroke care or did not complete the survey appropriately, 2564 surveys were analyzed. Analysis of the participants' scores revealed that 41.1% were burned out. Multivariable analysis indicated that number of hours worked per week is positively associated with burnout. Hours slept per night, day-offs per week, years of experience, as well as income, are inversely associated with burnout. Short Form 36 mental health subscale was also inversely associated with burnout. The primary risk factors for burnout are heavy workload, short sleep duration, relatively little experience, and low mental quality of life. Prospective research is required to confirm these findings and develop programs for preventing burnout. © 2014 American Heart Association, Inc.

Program interruptions and short-stay transfers represent potential targets for inpatient rehabilitation care-improvement efforts

PubMed Central

Middleton, Addie; Graham, James E.; Krishnan, Shilpa; Ottenbacher, Kenneth J.

2016-01-01

Objective To present comprehensive descriptive summaries of program interruptions and short-stay transfers among Medicare fee-for-service beneficiaries receiving inpatient rehabilitation following stroke, traumatic brain injury (TBI), and traumatic spinal cord injury (SCI). Design Retrospective cohort study of Medicare beneficiaries with any of the three conditions of interest who were admitted to inpatient rehabilitation directly from an acute hospital between July 1, 2012 and November 15, 2013. Results In the final sample (stroke: n=71 769; TBI: n=7109; SCI: n=659), program interruption rates were 0.9% (stroke), 0.8% (TBI), and 1.4% (SCI). Short-stay transfer rates were 22.3% (stroke), 21.8% (TBI), and 31.6% (SCI). 14.7% of short-stay transfers and 12.3% of interruptions resulting in a return to acute care were identified as potentially preventable among those with stroke, 10.2% of transfers and 11.7% of interruptions among those with TBI, and 3.8% of transfers and 11.1% of interruptions among those with SCI. Conclusions Broad healthcare policies aimed at improving quality and reducing costs are currently being implemented. Reducing program interruptions and short-stay transfers during inpatient rehabilitative care represents a potential target for care-improvement efforts. Future research focused on identifying modifiable risk factors for potentially undesirable outcomes will allow for targeted preventative interventions. PMID:27631389

Program Interruptions and Short-Stay Transfers Represent Potential Targets for Inpatient Rehabilitation Care-Improvement Efforts.

PubMed

Middleton, Addie; Graham, James E; Krishnan, Shilpa; Ottenbacher, Kenneth J

2016-11-01

The objective of this work was to present comprehensive descriptive summaries of program interruptions and short-stay transfers among Medicare fee-for-service beneficiaries receiving inpatient rehabilitation after stroke, traumatic brain injury (TBI), and traumatic spinal cord injury (SCI). Retrospective cohort study of Medicare beneficiaries with any of the 3 conditions of interest who were admitted to inpatient rehabilitation directly from an acute hospital between July 1, 2012, and November 15, 2013. In the final sample (stroke, n = 71 769; TBI, n = 7109; SCI, n = 659), program interruption rates were 0.9% (stroke), 0.8% (TBI), and 1.4% (SCI). Short-stay transfer rates were 22.3% (stroke), 21.8% (TBI), and 31.6% (SCI); 14.7% of short-stay transfers and 12.3% of interruptions resulting in a return to acute care were identified as potentially preventable among those with stroke; 10.2% of transfers and 11.7% of interruptions among those with TBI, and 3.8% of transfers and 11.1% of interruptions among those with SCI. Broad health care policies aimed at improving quality and reducing costs are currently being implemented. Reducing program interruptions and short-stay transfers during inpatient rehabilitative care represents a potential target for care-improvement efforts. Future research focused on identifying modifiable risk factors for potentially undesirable outcomes will allow for targeted preventative interventions.

Beneficial effects of footbaths in controlling spasticity after stroke

NASA Astrophysics Data System (ADS)

Matsumoto, Shuji; Shimodozono, Megumi; Etoh, Seiji; Shimozono, Yurika; Tanaka, Nobuyuki; Kawahira, Kazumi

2010-07-01

Footbaths are considered to provide beneficial thermal therapy for post-stroke patients with spasticity, but their anti-spastic effects have not been investigated comprehensively. The present study aimed to evaluate alterations in motor-neuron excitability using F-wave parameters in post-stroke patients with spastic hemiplegia. Subjects’ legs below the knee joint were immersed in water at 41°C and F-wave recordings were made over the abductor hallucis muscle before, immediately after, and 30 min after thermal treatment. Antidromic stimulation was performed on the tibial nerve at the ankle. Measurements included F-wave amplitude, F-wave/M-response ratio, changes in modified Ashworth scale (MAS), body temperature and surface-skin temperature. The mean values of both F-wave parameters were higher on the affected side before footbath treatment. In post-stroke patients, the mean values of F-wave parameters were significantly reduced after footbath treatment ( P < 0.01). The anti-spastic effects of footbath treatment were indicated by decreased F-wave parameters, in parallel with decreases in MAS. Body temperature was significantly increased both immediately after, and 30 min following footbath treatment in both groups, which appeared to play an important role in decreased spasticity. Surface-skin temperature increased immediately after footbath treatment in both groups and returned to baseline 30 min later. These findings demonstrate that the use of footbaths is an effective nonpharmacological anti-spastic treatment that might facilitate stroke rehabilitation.

Do measures of reactive balance control predict falls in people with stroke returning to the community?

PubMed

Mansfield, A; Wong, J S; McIlroy, W E; Biasin, L; Brunton, K; Bayley, M; Inness, E L

2015-12-01

To determine if reactive balance control measures predict falls after discharge from stroke rehabilitation. Prospective cohort study. Rehabilitation hospital and community. Independently ambulatory individuals with stroke who were discharged home after inpatient rehabilitation (n=95). Balance and gait measures were obtained from a clinical assessment at discharge from inpatient stroke rehabilitation. Measures of reactive balance control were obtained: (1) during quiet standing; (2) when walking; and (3) in response to large postural perturbations. Participants reported falls and activity levels up to 6 months post-discharge. Logistic and Poisson regressions were used to identify measures of reactive balance control that were related to falls post-discharge. Decreased paretic limb contribution to standing balance control [rate ratio 0.8, 95% confidence interval (CI) 0.7 to 1.0; P=0.011], reduced between-limb synchronisation of quiet standing balance control (rate ratio 0.9, 95% CI 0.8 to 0.9; P<0.0001), increased step length variability (rate ratio 1.4, 95% CI 1.2 to 1.7; P=0.0011) and inability to step with the blocked limb (rate ratio 1.2, 95% CI 1.0 to 1.3; P=0.013) were significantly associated with increased fall rates when controlling for age, stroke severity, functional balance and daily walking activity. Impaired reactive balance control in standing and walking predicted increased risk of falls post-discharge from stroke rehabilitation. Specifically, measures that revealed the capacity of both limbs to respond to instability were related to increased risk of falls. These results suggest that post-stroke rehabilitation strategies for falls prevention should train responses to instability, and focus on remediating dyscontrol in the more-affected limb. Copyright © 2015 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

[The effect of neurorehabilitation on the functional state and muscle tone of upper limb in patients after ischaemic stroke].

PubMed

Klimkiewicz, Paulina; Kubsik, Anna; Jankowska, Agnieszka; Woldańska-Okońska, Marta

2014-03-01

Rehabilitation of upper limb in patients after ischemic stroke is a major challenge for modern neurorehabilitation. Function of upper limb of patients after ischemic stroke returns on the end of the rehabilitation comparing with another parts of the body. Below presents two groups of patients after ischemic stroke who were rehabilitated with use of the following methods: kinesiotherapy combined with NDT- Bobath method and kinesiotherapy only. The aim of this study was to assess the impact of kinesiotherapy only and NDT- Bobath method combined with kinesiotherapy on the functional state and muscle tone of upper limb in patients after ischemic stroke. The study involved a group of 40 patients after ischemic stroke with motor control and muscle tone problems of upper limb. Patients were divided into two groups, each of them included 20 people. Upper limb in group I was rehabilitated with the use of kinesiotherapy exercise however group II with the use of kinesiotherapy exercise combined with NDT- Bobath method (Neurodevelopmental Treatment Bobath). To evaluate the patients before and after rehabilitation muscle tone Asworth scale was used and to assess functional status Rivermead Motor Assessment (RMAIII) scale was used. After 5 weeks of rehabilitation in group II in majority patients were observed decrease of muscle tone and improvement in upper limb functional status. In group I the muscle tone were also decreased and functional status were better but in smaller impact than in II group. Classical kinesiotherapy combined with the NDT-Bobath method gives better results in neurorehabilitation of upper limb than the use of kinesiotherapy exercises only in patients after ischemic stroke.

Geology of Potential Landing Sites for Martian Sample Returns

NASA Technical Reports Server (NTRS)

Greeley, Ronald

2003-01-01

This project involved the analysis of potential landing sites on Mars. As originally proposed, the project focused on landing sites from which samples might be returned to Earth. However, as the project proceeded, the emphasis shifted to missions that would not include sample return, because the Mars Exploration Program had deferred sample returns to the next decade. Subsequently, this project focused on the study of potential landing sites for the Mars Exploration Rovers.

Occlusion of M1 segment after superficial temporal artery-middle cerebral artery bypass in a giant M1 aneurysm with Onyx-34 injected via a double-lumen balloon under balloon inflation.

PubMed

Clarençon, Frédéric; Nouet, Aurelien; Redondo, Aimée; Di Maria, Federico; Iosif, Christina; Le Jean, Lise; Chiras, Jacques; Sourour, Nader

2013-05-31

A 29-year-old patient attended our institution for recurrent strokes related to a giant partially thrombosed M1 aneurysm. Superficial temporal artery-middle cerebral artery (STA-MCA) bypass and subsequent occlusion of both the aneurysm and the dysplastic M1 segment were planned. However, owing to the shortness of the non-dysplastic segment of M1 and the risk of occlusion of the lenticulostriate arteries, the use of a double-lumen balloon was considered for coiling and subsequent injection of Onyx. STA-MCA bypass was performed using a regular technique. Endovascular occlusion of both the aneurysm and the parent artery was subsequently performed by means of coils and Onyx-34 that was injected via the Ascent balloon under balloon inflation. No complications were recorded and no stroke was observed on control MRI. The injection of Onyx-34 through a double-lumen balloon under balloon inflation is a quick and safe technique for precise occlusion of a parent artery.

Occlusion of M1 segment after superficial temporal artery-middle cerebral artery bypass in a giant M1 aneurysm with Onyx-34 injected via a double-lumen balloon under balloon inflation.

PubMed

Clarençon, Frédéric; Nouet, Aurelien; Redondo, Aimée; Di Maria, Federico; Iosif, Christina; Le Jean, Lise; Chiras, Jacques; Sourour, Nader

2014-05-01

A 29-year-old patient attended our institution for recurrent strokes related to a giant partially thrombosed M1 aneurysm. Superficial temporal artery-middle cerebral artery (STA-MCA) bypass and subsequent occlusion of both the aneurysm and the dysplastic M1 segment were planned. However, owing to the shortness of the non-dysplastic segment of M1 and the risk of occlusion of the lenticulostriate arteries, the use of a double-lumen balloon was considered for coiling and subsequent injection of Onyx. STA-MCA bypass was performed using a regular technique. Endovascular occlusion of both the aneurysm and the parent artery was subsequently performed by means of coils and Onyx-34 that was injected via the Ascent balloon under balloon inflation. No complications were recorded and no stroke was observed on control MRI. The injection of Onyx-34 through a double-lumen balloon under balloon inflation is a quick and safe technique for precise occlusion of a parent artery.

Occlusion of M1 segment after superficial temporal artery-middle cerebral artery bypass in a giant M1 aneurysm with Onyx-34 injected via a double-lumen balloon under balloon inflation

PubMed Central

Clarençon, Frédéric; Nouet, Aurelien; Redondo, Aimée; Di Maria, Federico; Iosif, Christina; Le Jean, Lise; Chiras, Jacques; Sourour, Nader

2013-01-01

A 29-year-old patient attended our institution for recurrent strokes related to a giant partially thrombosed M1 aneurysm. Superficial temporal artery-middle cerebral artery (STA-MCA) bypass and subsequent occlusion of both the aneurysm and the dysplastic M1 segment were planned. However, owing to the shortness of the non-dysplastic segment of M1 and the risk of occlusion of the lenticulostriate arteries, the use of a double-lumen balloon was considered for coiling and subsequent injection of Onyx. STA-MCA bypass was performed using a regular technique. Endovascular occlusion of both the aneurysm and the parent artery was subsequently performed by means of coils and Onyx-34 that was injected via the Ascent balloon under balloon inflation. No complications were recorded and no stroke was observed on control MRI. The injection of Onyx-34 through a double-lumen balloon under balloon inflation is a quick and safe technique for precise occlusion of a parent artery. PMID:23729720

Comprehensive CT Evaluation in Acute Ischemic Stroke: Impact on Diagnosis and Treatment Decisions

PubMed Central

Löve, Askell; Siemund, Roger; Andsberg, Gunnar; Cronqvist, Mats; Holtås, Stig; Björkman-Burtscher, Isabella

2011-01-01

Background. With modern CT imaging a comprehensive overview of cerebral macro- and microcirculation can be obtained within minutes in acute ischemic stroke. This opens for patient stratification and individualized treatment. Methods. Four patients with acute ischemic stroke of different aetiologies and/or treatments were chosen for illustration of the comprehensive CT protocol and its value in subsequent treatment decisions. The patients were clinically evaluated according to the NIHSS-scale, examined with the comprehensive CT protocol including both CT angiography and CT perfusion, and followed up by MRI. Results. The comprehensive CT examination protocol increased the examination time but did not delay treatment initiation. In some cases CT angiography revealed the cause of stroke while CT perfusion located and graded the perfusion defect with reasonable accuracy, confirmed by follow-up MR-diffusion. In the presented cases findings of the comprehensive CT examination influenced the treatment strategy. Conclusions. The comprehensive CT examination is a fast and safe method allowing accurate diagnosis and making way for individualized treatment in acute ischemic stroke. PMID:21603175

Cerebral small vessel disease: Capillary pathways to stroke and cognitive decline

PubMed Central

Engedal, Thorbjørn S; Moreton, Fiona; Hansen, Mikkel B; Wardlaw, Joanna M; Dalkara, Turgay; Markus, Hugh S; Muir, Keith W

2015-01-01

Cerebral small vessel disease (SVD) gives rise to one in five strokes worldwide and constitutes a major source of cognitive decline in the elderly. SVD is known to occur in relation to hypertension, diabetes, smoking, radiation therapy and in a range of inherited and genetic disorders, autoimmune disorders, connective tissue disorders, and infections. Until recently, changes in capillary patency and blood viscosity have received little attention in the aetiopathogenesis of SVD and the high risk of subsequent stroke and cognitive decline. Capillary flow patterns were, however, recently shown to limit the extraction efficacy of oxygen in tissue and capillary dysfunction therefore proposed as a source of stroke-like symptoms and neurodegeneration, even in the absence of physical flow-limiting vascular pathology. In this review, we examine whether capillary flow disturbances may be a shared feature of conditions that represent risk factors for SVD. We then discuss aspects of capillary dysfunction that could be prevented or alleviated and therefore might be of general benefit to patients at risk of SVD, stroke or cognitive decline. PMID:26661176

Extracranial-intracranial bypass surgery for stroke prevention in hemodynamic cerebral ischemia: the Carotid Occlusion Surgery Study randomized trial.

PubMed

Powers, William J; Clarke, William R; Grubb, Robert L; Videen, Tom O; Adams, Harold P; Derdeyn, Colin P

2011-11-09

Patients with symptomatic atherosclerotic internal carotid artery occlusion (AICAO) and hemodynamic cerebral ischemia are at high risk for subsequent stroke when treated medically. To test the hypothesis that extracranial-intracranial (EC-IC) bypass surgery, added to best medical therapy, reduces subsequent ipsilateral ischemic stroke in patients with recently symptomatic AICAO and hemodynamic cerebral ischemia. Parallel-group, randomized, open-label, blinded-adjudication clinical treatment trial conducted from 2002 to 2010. Forty-nine clinical centers and 18 positron emission tomography (PET) centers in the United States and Canada. The majority were academic medical centers. Patients with arteriographically confirmed AICAO causing hemispheric symptoms within 120 days and hemodynamic cerebral ischemia identified by ipsilateral increased oxygen extraction fraction measured by PET. Of 195 patients who were randomized, 97 were randomized to receive surgery and 98 to no surgery. Follow-up for the primary end point until occurrence, 2 years, or termination of trial was 99% complete. No participant withdrew because of adverse events. Anastomosis of superficial temporal artery branch to a middle cerebral artery cortical branch for the surgical group. Antithrombotic therapy and risk factor intervention were recommended for all participants. For all participants who were assigned to surgery and received surgery, the combination of (1) all stroke and death from surgery through 30 days after surgery and (2) ipsilateral ischemic stroke within 2 years of randomization. For the nonsurgical group and participants assigned to surgery who did not receive surgery, the combination of (1) all stroke and death from randomization to randomization plus 30 days and (2) ipsilateral ischemic stroke within 2 years of randomization. The trial was terminated early for futility. Two-year rates for the primary end point were 21.0% (95% CI, 12.8% to 29.2%; 20 events) for the surgical group and 22.7% (95% CI, 13.9% to 31.6%; 20 events) for the nonsurgical group (P = .78, Z test), a difference of 1.7% (95% CI, -10.4% to 13.8%). Thirty-day rates for ipsilateral ischemic stroke were 14.4% (14/97) in the surgical group and 2.0% (2/98) in the nonsurgical group, a difference of 12.4% (95% CI, 4.9% to 19.9%). Among participants with recently symptomatic AICAO and hemodynamic cerebral ischemia, EC-IC bypass surgery plus medical therapy compared with medical therapy alone did not reduce the risk of recurrent ipsilateral ischemic stroke at 2 years. clinicaltrials.gov Identifier: NCT00029146.

Feasibility, safety and cost of outpatient management of acute minor ischaemic stroke: a population-based study.

PubMed

Paul, Nicola L M; Koton, Silvia; Simoni, Michela; Geraghty, Olivia C; Luengo-Fernandez, Ramon; Rothwell, Peter M

2013-03-01

Outpatient management safely and effectively prevents early recurrent stroke after transient ischaemic attack (TIA), but this approach may not be safe in patients with acute minor stroke. To study outcomes of clinic and hospital-referred patients with TIA or minor stroke (National Institute of Health Stroke Scale score ≤3) in a prospective, population-based study (Oxford Vascular Study). Of 845 patients with TIA/stroke, 587 (69%) were referred directly to outpatient clinics and 258 (31%) directly to inpatient services. Of the 250 clinic-referred minor strokes (mean age 72.7 years), 237 (95%) were investigated, treated and discharged on the same day, of whom 16 (6.8%) were subsequently admitted to hospital within 30 days for recurrent stroke (n=6), sepsis (n=3), falls (n=3), bleeding (n=2), angina (n=1) and nursing care (n=1). The 150 patients (mean age 74.8 years) with minor stroke referred directly to hospital (median length-of-stay 9 days) had a similar 30-day readmission rate (9/150; 6.3%; p=0.83) after initial discharge and a similar 30-day risk of recurrent stroke (9/237 in clinic patients vs 8/150, OR=0.70, 0.27-1.80, p=0.61). Rates of prescription of secondary prevention medication after initial clinic/hospital discharge were higher in clinic-referred than in hospital-referred patients for antiplatelets/anticoagulants (p<0.05) and lipid-lowering agents (p<0.001) and were maintained at 1-year follow-up. The mean (SD) secondary care cost was £8323 (13 133) for hospital-referred minor stroke versus £743 (1794) for clinic-referred cases. Outpatient management of clinic-referred minor stroke is feasible and may be as safe as inpatient care. Rates of early hospital admission and recurrent stroke were low and uptake and maintenance of secondary prevention was high.

A protocol for a prospective observational study using chest and thumb ECG: transient ECG assessment in stroke evaluation (TEASE) in Sweden.

PubMed

Magnusson, Peter; Koyi, Hirsh; Mattsson, Gustav

2018-04-03

Atrial fibrillation (AF) causes ischaemic stroke and based on risk factor evaluation warrants anticoagulation therapy. In stroke survivors, AF is typically detected with short-term ECG monitoring in the stroke unit. Prolonged continuous ECG monitoring requires substantial resources while insertable cardiac monitors are invasive and costly. Chest and thumb ECG could provide an alternative for AF detection poststroke.The primary objective of our study is to assess the incidence of newly diagnosed AF during 28 days of chest and thumb ECG monitoring in cryptogenic stroke. Secondary objectives are to assess health-related quality of life (HRQoL) using short-form health survey (SF-36) and the feasibility of the Coala Heart Monitor in patients who had a stroke. Stroke survivors in Region Gävleborg, Sweden, will be eligible for the study from October 2017. Patients with a history of ischaemic stroke without documented AF before or during ECG evaluation in the stroke unit will be evaluated by the chest and thumb ECG system Coala Heart Monitor. The monitoring system is connected to a smartphone application which allows for remote monitoring and prompt advice on clinical management. Over a period of 28 days, patients will be monitored two times a day and may activate the ECG recording at symptoms. On completion, the system is returned by mail. This system offers a possibility to evaluate the presence of AF poststroke, but the feasibility of this system in patients who recently suffered from a stroke is unknown. In addition, HRQoL using SF-36 in comparison to Swedish population norms will be assessed. The feasibility of the Coala Heart Monitor will be assessed by a self-developed questionnaire. The study was approved by The Regional Ethical Committee in Uppsala (2017/321). The database will be closed after the last follow-up, followed by statistical analyses, interpretation of results and dissemination to a scientific journal. NCT03301662; Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Multidisciplinary transmural rehabilitation for older persons with a stroke: the design of a randomised controlled trial.

PubMed

Vluggen, Tom P M M; van Haastregt, Jolanda C M; Verbunt, Jeanine A; Keijsers, Elly J M; Schols, Jos M G A

2012-12-31

Stroke is one of the major causes of loss of independence, decreased quality of life and mortality among elderly people. About half of the elderly stroke patients discharged after rehabilitation in a nursing home still experience serious impairments in daily functioning one year post stroke, which can lead to difficulties in picking up and managing their social life. The aim of this study is to evaluate the effectiveness and feasibility of a new multidisciplinary transmural rehabilitation programme for older stroke patients. A two group multicentre randomised controlled trial is used to evaluate the effects of the rehabilitation programme. The programme consists of three care modules: 1) neurorehabilitation treatment for elderly stroke patients; 2) empowerment training for patient and informal caregiver; and 3) stroke education for patient and informal caregiver. The total programme has a duration of between two and six months, depending on the individual problems of the patient and informal caregiver. The control group receives usual care in the nursing home and after discharge. Patients aged 65 years and over are eligible for study participation when they are admitted to a geriatric rehabilitation unit in a nursing home due to a recent stroke and are expected to be able to return to their original home environment after discharge. Data are gathered by face-to-face interviews, self-administered questionnaires, focus groups and registration forms. Primary outcomes for patients are activity level after stroke, functional dependence, perceived quality of life and social participation. Outcomes for informal caregivers are perceived care burden, objective care burden, quality of life and perceived health. Outcome measures of the process evaluation are implementation fidelity, programme deliverance and the opinion of the stroke professionals, patients and informal caregivers about the programme. Outcome measures of the economic evaluation are the healthcare utilisation and associated costs. Data are collected at baseline, and after six and 12 months. The first results of the study will be expected in 2014. International Standard Randomised Controlled Trial Register Number ISRCTN62286281, The Dutch Trial Register NTR2412.

Prediction of outcome in neurogenic oropharyngeal dysphagia within 72 hours of acute stroke.

PubMed

Ickenstein, Guntram W; Höhlig, Carolin; Prosiegel, Mario; Koch, Horst; Dziewas, Rainer; Bodechtel, Ulf; Müller, Rainer; Reichmann, Heinz; Riecker, Axel

2012-10-01

Stroke is the most frequent cause of neurogenic oropharyngeal dysphagia (NOD). In the acute phase of stroke, the frequency of NOD is greater than 50% and, half of this patient population return to good swallowing within 14 days while the other half develop chronic dysphagia. Because dysphagia leads to aspiration pneumonia, malnutrition, and in-hospital mortality, it is important to pay attention to swallowing problems. The question arises if a prediction of severe chronic dysphagia is possible within the first 72 hours of acute stroke. On admission to the stroke unit, all stroke patients were screened for swallowing problems by the nursing staff within 2 hours. Patients showing signs of aspiration were included in the study (n = 114) and were given a clinical swallowing examination (CSE) by the swallowing/speech therapist within 24 hours and a swallowing endoscopy within 72 hours by the physician. The primary outcome of the study was the functional communication measure (FCM) of swallowing (score 1-3, tube feeding dependency) on day 90. The grading system with the FCM swallowing and the penetration-aspiration scale (PAS) in the first 72 hours was tested in a multivariate analysis for its predictive value for tube feeding-dependency on day 90. For the FCM level 1 to 3 (P < .0022) and PAS level 5 to 8 (P < .00001), the area under the curve (AUC) was 72.8% and showed an odds ratio of 11.8 (P < .00001; 95% confidence interval 0.036-0.096), achieving for the patient a 12 times less chance of being orally fed on day 90 and therefore still being tube feeding-dependent. We conclude that signs of aspiration in the first 72 hours of acute stroke can predict severe swallowing problems on day 90. Consequently, patients should be tested on admission to a stroke unit and evaluated with established dysphagia scales to prevent aspiration pneumonia and malnutrition. A dysphagia program can lead to better communication within the stroke unit team to initiate the appropriate diagnostics and swallowing therapy as soon as possible. Copyright © 2012 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Is management of hyperglycaemia in acute phase stroke still a dilemma?

PubMed

Savopoulos, C; Kaiafa, G; Kanellos, I; Fountouki, A; Theofanidis, D; Hatzitolios, A I

2017-05-01

Close monitoring of blood glucose levels during the immediate post-acute stroke phase is of great clinical value, as there is evidence that the risk of neurological deterioration is associated with both hyper- and hypoglycaemia. The aim of this review paper is to summarise the evidence on post-stroke blood glucose management and its impact on clinical outcomes, during the early post-acute stage. Post-stroke hyperglycaemia has been associated with increased cerebral oedema, haemorrhagic transformation, lower likelihood of recanalisation and deteriorating neurological state. Thus, hyperglycaemia during an acute stroke may result in poorer clinical outcomes, infarct progression, poor functional recovery and increased mortality rates. Although hypoglycaemia may also lead to poorer outcomes via further brain injury, it can be readily reversed by glucose administration. In most patients, the goal of regular treatment is euglycaemia and for acute-stroke patients, a reasonable approach is to target control of glucose level at 100-150 mg/dL. Both hypoglycaemia and hyperglycaemia may lead to further brain injury and clinical deterioration; that is the reason these conditions should be avoided after stroke. Yet, when correcting hyperglycaemia, great care should be taken not to switch the patient into hypoglycaemia, and subsequently aggressive insulin administration treatment should be avoided. Early identification and prompt management of hyperglycaemia, especially in acute ischaemic stroke, is recommended. Although the appropriate level of blood glucose during acute stroke is still debated, a reasonable approach is to keep the patient in a mildly hyperglycaemic state, rather than risking hypoglycaemia, using continuous glucose monitoring.

Tocotrienol vitamin E protects against preclinical canine ischemic stroke by inducing arteriogenesis

PubMed Central

Rink, Cameron; Christoforidis, Greg; Khanna, Savita; Peterson, Laura; Patel, Yojan; Khanna, Suchin; Abduljalil, Amir; Irfanoglu, Okan; Machiraju, Raghu; Bergdall, Valerie K; Sen, Chandan K

2011-01-01

Vitamin E consists of tocopherols and tocotrienols, in which α-tocotrienol is the most potent neuroprotective form that is also effective in protecting against stroke in rodents. As neuroprotective agents alone are insufficient to protect against stroke, we sought to test the effects of tocotrienol on the cerebrovascular circulation during ischemic stroke using a preclinical model that enables fluoroscopy-guided angiography. Mongrel canines (mean weight=26.3±3.2 kg) were supplemented with tocotrienol-enriched (TE) supplement (200 mg b.i.d, n=11) or vehicle placebo (n=9) for 10 weeks before inducing transient middle cerebral artery (MCA) occlusion. Magnetic resonance imaging was performed 1 hour and 24 hours post reperfusion to assess stroke-induced lesion volume. Tocotrienol-enriched supplementation significantly attenuated ischemic stroke-induced lesion volume (P<0.005). Furthermore, TE prevented loss of white matter fiber tract connectivity after stroke as evident by probabilistic tractography. Post hoc analysis of cerebral angiograms during MCA occlusion revealed that TE-supplemented canines had improved cerebrovascular collateral circulation to the ischemic MCA territory (P<0.05). Tocotrienol-enriched supplementation induced arteriogenic tissue inhibitor of metalloprotease 1 and subsequently attenuated the activity of matrix metalloproteinase-2. Outcomes of the current preclinical trial set the stage for a clinical trial testing the effects of TE in patients who have suffered from transient ischemic attack and are therefore at a high risk for stroke. PMID:21673716

Functioning in everyday life after stroke: a longitudinal study of elderly people receiving rehabilitation at home.

PubMed

Ekstam, Lisa; Uppgard, Brittmari; von Koch, Lena; Tham, Kerstin

2007-12-01

There is a need to identify different rehabilitation needs over time among individuals with stroke in order to implement client-centred rehabilitation interventions after stroke. The objective of this research was to describe changes in some aspects of functioning and to explore the patterns of change in functioning in everyday life during the first year after stroke for elderly patients participating in rehabilitation at home. Patients who fulfilled the inclusion criteria for a regular rehabilitation-at-home programme after stroke were considered for participation in this study. Twenty-seven elderly patients participated on four data collection occasions during the year immediately subsequent to a stroke. The mean age of the 27 participants was 78.8 years (SD = 5.9) and 67% of the participants were women. Data on certain aspects of functioning were collected and a person-oriented approach was used to describe the patterns in the change in functioning for individuals. Four different patterns were identified: (a) moderate change in functioning (n = 4), (b) minor change in functioning (n = 11), (c) minor change despite major life event (n = 7), (d) disrupted change in functioning (n = 5). The study group improved significantly in most aspects of functioning, but still, most participants (n = 20) showed dissatisfaction with life as a whole 12 months after their stroke. This study identified different patterns of change in functioning in everyday life. This knowledge should serve to help guide rehabilitation professionals in their assessment of clients' needs during different phases after stroke.

A single trial of transcutaneous electrical nerve stimulation (TENS) improves spasticity and balance in patients with chronic stroke.

PubMed

Cho, Hwi-young; In, Tae Sung; Cho, Ki Hun; Song, Chang Ho

2013-03-01

Spasticity management is pivotal for achieving functional recovery of stroke patients. The purpose of this study was to investigate the effects of a single trial of transcutaneous electrical nerve stimulation (TENS) on spasticity and balance in chronic stroke patients. Forty-two chronic stroke patients were randomly allocated into the TENS (n = 22) or the placebo-TENS (n = 20) group. TENS stimulation was applied to the gastrocnemius for 60 min at 100 Hz, 200 µs with 2 to 3 times the sensory threshold (the minimal threshold in detecting electrical stimulation for subjects) after received physical therapy for 30 min. In the placebo-TENS group, electrodes were placed but no electrical stimulation was administered. For measuring spasticity, the resistance encountered during passive muscle stretching of ankle joint was assessed using the Modified Ashworth Scale, and the Hand held dynamometer was used to assess the resistive force caused by spasticity. Balance ability was measured using a force platform that measures postural sway generated by postural imbalance. The TENS group showed a significantly greater reduction in spasticity of the gastrocnemius, compared to the placebo-TENS group (p < 0.05). TENS resulted in greater balance ability improvements, especially during the eyes closed condition (p < 0.05). However, these effects returned to baseline values within one day. This study shows that TENS provides an immediately effective means of reducing spasticity and of improving balance in chronic stroke patients. The present data may be useful to establish the standard parameters for TENS application in the clinical setting of stroke.

Effect of a care plan based on Roy adaptation model biological dimension on stroke patients' physiologic adaptation level.

PubMed

Alimohammadi, Nasrollah; Maleki, Bibi; Shahriari, Mohsen; Chitsaz, Ahmad

2015-01-01

Stroke is a stressful event with several functional, physical, psychological, social, and economic problems that affect individuals' different living balances. With coping strategies, patients try to control these problems and return to their natural life. The aim of this study is to investigate the effect of a care plan based on Roy adaptation model biological dimension on stroke patients' physiologic adaptation level. This study is a clinical trial in which 50 patients, affected by brain stroke and being admitted in the neurology ward of Kashani and Alzahra hospitals, were randomly assigned to control and study groups in Isfahan in 2013. Roy adaptation model care plan was administered in biological dimension in the form of four sessions and phone call follow-ups for 1 month. The forms related to Roy adaptation model were completed before and after intervention in the two groups. Chi-square test and t-test were used to analyze the data through SPSS 18. There was a significant difference in mean score of adaptation in physiological dimension in the study group after intervention (P < 0.001) compared to before intervention. Comparison of the mean scores of changes of adaptation in the patients affected by brain stroke in the study and control groups showed a significant increase in physiological dimension in the study group by 47.30 after intervention (P < 0.001). The results of study showed that Roy adaptation model biological dimension care plan can result in an increase in adaptation in patients with stroke in physiological dimension. Nurses can use this model for increasing patients' adaptation.

Effect of acupuncture on insomnia following stroke: study protocol for a randomized controlled trial.

PubMed

Cao, Yan; Yin, Xuan; Soto-Aguilar, Francisca; Liu, Yiping; Yin, Ping; Wu, Junyi; Zhu, Bochang; Li, Wentao; Lao, Lixing; Xu, Shifen

2016-11-16

The incidence, mortality, and prevalence of stroke are high in China. Stroke is commonly associated with insomnia; both insomnia and stroke have been effectively treated with acupuncture for a long time. The aim of this proposed trial is to assess the therapeutic effect of acupuncture on insomnia following stroke. This proposed study is a single-center, single-blinded (patient-assessor-blinded), parallel-group randomized controlled trial. We will randomly assign 60 participants with insomnia following stroke into two groups in a 1:1 ratio. The intervention group will undergo traditional acupuncture that achieves the De-qi sensation, and the control group will receive sham acupuncture without needle insertion. The same acupoints (DU20, DU24, EX-HN3, EX-HN22, HT7, and SP6) will be used in both groups. Treatments will be given to all participants three times a week for the subsequent 4 weeks. The primary outcome will be the Pittsburgh Sleep Quality Index. The secondary outcomes will be: the Insomnia Severity Index; sleep efficacy, sleep awakenings, and total sleep time recorded via actigraphy; the National Institutes of Health Stroke Scale; the Stroke-Specific Quality of Life score; the Hospital Anxiety and Depression Scale. The use of estazolam will be permitted and regulated under certain conditions. Outcomes will be assessed at baseline, 2 weeks after treatment commencement, 4 weeks after treatment commencement, and at the 8-week follow-up. This proposed study will contribute to expanding knowledge about acupuncture treatment for insomnia following stroke. This will be a high-quality randomized controlled trial with strict methodology and few design deficits. It will investigate the effectiveness of acupuncture as an alternative treatment for insomnia following stroke. Chinese Clinical Trial Registry identifier: ChiCTR-IIC-16008382 . Registered on 28 April 2016.

Determinants and Outcomes of Stroke Following Percutaneous Coronary Intervention by Indication.

PubMed

Myint, Phyo Kyaw; Kwok, Chun Shing; Roffe, Christine; Kontopantelis, Evangelos; Zaman, Azfar; Berry, Colin; Ludman, Peter F; de Belder, Mark A; Mamas, Mamas A

2016-06-01

Stroke after percutaneous coronary intervention (PCI) is a serious complication, but its determinants and outcomes after PCI in different clinical settings are poorly documented. The British Cardiovascular Intervention Society (BCIS) database was used to study 560 439 patients who underwent PCI in England and Wales between 2006 and 2013. We examined procedural-type specific determinants of ischemic and hemorrhagic stroke and the likelihood of subsequent 30-day mortality and in-hospital major adverse cardiovascular events (a composite of in-hospital mortality, myocardial infarction or reinfarction, and repeat revascularization). A total of 705 stroke cases were recorded (80% ischemic). Stroke after an elective PCI or PCI for acute coronary syndrome indications was associated with a higher risk of adverse outcomes compared with those without stroke; 30-day mortality and major adverse cardiovascular events outcomes in fully adjusted model were odds ratios 37.90 (21.43-67.05) and 21.05 (13.25-33.44) for elective and 5.00 (3.96-6.31) and 6.25 (5.03-7.77) for acute coronary syndrome, respectively. Comparison of odds of these outcomes between these 2 settings showed no differences; corresponding odds ratios were 1.24 (0.64-2.43) and 0.63 (0.35-1.15), respectively. Hemorrhagic and ischemic stroke complications are uncommon, but serious complications can occur after PCI and are independently associated with worse mortality and major adverse cardiovascular events outcomes in both the elective and acute coronary syndrome setting irrespective of stroke type. Our study provides a better understanding of the risk factors and prognosis of stroke after PCI by procedure type, allowing physicians to provide more informed advice around stroke risk after PCI and counsel patients and their families around outcomes if such neurological complications occur. © 2016 American Heart Association, Inc.

Post-ischemic stroke rehabilitation is associated with a higher risk of fractures in older women: A population-based cohort study

PubMed Central

Yang, Clement Shih Hsien; Liang, Chung Chao

2017-01-01

Background Rehabilitation can improve physical activity after stroke. However, patients may be more prone to falls and fractures because of balance and gait deficits. Few reports have studied the relationship between rehabilitation and subsequent fractures after ischemic stroke. Objective To investigate whether post-stroke rehabilitation affects fracture risk. Methods We conducted a population-based retrospective cohort study based on the Taiwan National Health Insurance Research Database. Patients with a newly diagnosed ischemic stroke between 2000 and 2012 were included. After propensity score matching, a total of 8,384 patients were enrolled. Half of the patients (4,192) received post-stroke rehabilitation within 1 month; the other half did not receive any post-stroke rehabilitation. Cox proportional hazards regression model was used to calculate hazard ratios (HRs) for fractures among patients with and without rehabilitation within 1 year after ischemic stroke. Patients were further stratified by sex and age (20–64 and ≥65 years). Results Patients receiving post-stroke rehabilitation had a higher incidence of fracture (6.2 per 100 person-years) than those who did not (4.1 per 100 person-years) after adjustment for sociodemographic and coexisting medical conditions [HR = 1.53, 95% confidence interval (CI) = 1.25–1.87, p < 0.001]. The analyses performed after stratifying for sex and age showed that only older women undergoing rehabilitation had a significantly higher risk of fracture (HR = 1.62, 95% CI = 1.21–2.17, p = 0.001). Conclusion Rehabilitation after ischemic stroke is associated with an increased fracture risk in older women. PMID:28414796

Patent Foramen Ovale: Association between the Degree of Shunt by Contrast Transesophageal Echocardiography and the Risk of Future Ischemic Neurologic Events

NASA Technical Reports Server (NTRS)

Stone, David A.; Godard, Joel; Godard, Joel; Corretti, mary C.; Kittner, Steven J.; Sample, Cindy; Price, Thomas R.; Plotnick, Gary D.

1996-01-01

This study investigated whether there is an association between the degree of interatrial shunting across a patent foramen ovale, as determined by saline contrast transesophageal echocardiography, and the risk of subsequent systemic embolic events, including stroke. Thirty-four patients found to have patent foramen ovale during transesophageal echocardiography were divided into two groups on the basis of the maximum number of microbubbles in the left heart in any single frame after intravenous saline contrast injection: group 1 (n = 16) with a "large" degree of shunt (220 microbubbles) and group 2 (n = 18) with a "small" degree of shunt (23 but <20 microbubbles). Patients were followed up over a mean period of 21 months for subsequent systemic embolic events, including transient ischemic attack and stroke. Five (31%) of the patients with large shunts had subsequent ischemic neurologic events, whereas none of the patients with small shunts had embolic events (p= 0.03). These events occurred in spite of antiplatelet or anticoagulant therapy. We conclude that patients with a large degree of shunt across a patent foramen ovale, as determined by contrast transesophageal echocardiography, are at a significantly higher risk for subsequent adverse neurologic events compared with patients with a small degree of shunt.

Lower NIH stroke scale scores are required to accurately predict a good prognosis in posterior circulation stroke.

PubMed

Inoa, Violiza; Aron, Abraham W; Staff, Ilene; Fortunato, Gilbert; Sansing, Lauren H

2014-01-01

The NIH stroke scale (NIHSS) is an indispensable tool that aids in the determination of acute stroke prognosis and decision making. Patients with posterior circulation (PC) strokes often present with lower NIHSS scores, which may result in the withholding of thrombolytic treatment from these patients. However, whether these lower initial NIHSS scores predict better long-term prognoses is uncertain. We aimed to assess the utility of the NIHSS at presentation for predicting the functional outcome at 3 months in anterior circulation (AC) versus PC strokes. This was a retrospective analysis of a large prospectively collected database of adults with acute ischemic stroke. Univariate and multivariate analyses were conducted to identify factors associated with outcome. Additional analyses were performed to determine the receiver operating characteristic (ROC) curves for NIHSS scores and outcomes in AC and PC infarctions. Both the optimal cutoffs for maximal diagnostic accuracy and the cutoffs to obtain >80% sensitivity for poor outcomes were determined in AC and PC strokes. The analysis included 1,197 patients with AC stroke and 372 with PC stroke. The median initial NIHSS score for patients with AC strokes was 7 and for PC strokes it was 2. The majority (71%) of PC stroke patients had baseline NIHSS scores ≤4, and 15% of these 'minor' stroke patients had a poor outcome at 3 months. ROC analysis identified that the optimal NIHSS cutoff for outcome prediction after infarction in the AC was 8 and for infarction in the PC it was 4. To achieve >80% sensitivity for detecting patients with a subsequent poor outcome, the NIHSS cutoff for infarctions in the AC was 4 and for infarctions in the PC it was 2. The NIHSS cutoff that most accurately predicts outcomes is 4 points higher in AC compared to PC infarctions. There is potential for poor outcomes in patients with PC strokes and low NIHSS scores, suggesting that thrombolytic treatment should not be withheld from these patients based solely on the NIHSS. © 2014 S. Karger AG, Basel. © 2014 S. Karger AG, Basel.

Neurosurgical management of L-asparaginase induced haemorrhagic stroke

PubMed Central

Ogbodo, Elisha; Kaliaperumal, Chandrasekaran; O’Sullivan, Michael

2012-01-01

The authors describe a case of L-asparaginase induced intracranial thrombosis and subsequent haemorrhage in a newly diagnosed 30-year-old man with acute lymphoblastic leukaemia who was successfully managed by surgical intervention. At presentation, he had a Glasgow Coma Score of 7/15, was aphasic and had dense right hemiplegia. Neuroimaging revealed an acute anterior left middle cerebral artery infarct with parenchymal haemorrhagic conversion, mass effect and subfalcine herniation. He subsequently underwent left frontal craniotomy and evacuation of large frontal haematoma and decompressive craniectomy for cerebral oedema. Six months postoperatively he underwent titanium cranioplasty. He had made good clinical recovery and is currently mobilising independently with mild occasional episodes of expressive dysphasia, difficulty with fine motor movement on the right side, and has remained seizure free. This is the first documented case of L-asparaginase induced haemorrhagic stroke managed by neurosurgical intervention. The authors emphasise the possible role of surgery in managing chemotherapy induced intracranial complications. PMID:22605598

A survey to explore what information, advice and support community-dwelling people with stroke currently receive to manage instability and falls.

PubMed

Shovlin, Eleanor; Kunkel, Dorit

2017-09-13

To describe and determine the benefits of the information and support services currently offered to people with stroke experiencing instability and falls. A cross-sectional survey study. Two hundred and fifty-six surveys were sent out to community stroke groups in Hampshire and the Isle of Wight, as well as to people with stroke on a patient register. One hundred and twenty-five surveys were returned. A total of 107 participants (86%) reported instability and 62 (50%) had experienced a fall in the preceding year; 29 (28%) had reportedly received information on falls prevention. Forty-four participants (43%) sought help from health professionals following instability and falls; just over half reported that the information they received was useful. One quarter (n = 11) of those seeking help were referred on to falls clinics; all attended and 86% felt attending had been beneficial. However, only one participant was followed up by these clinics. Findings suggest that the majority of people with stroke who have experienced instability and falls did not receive any information and support, with very few referred on to falls clinics. Health professionals play a key role in information provision and facilitating access to falls prevention programs. Further research is required to determine the most effective ways to implement current guidelines to manage instability and falls in this high-risk group. Implications for rehabilitation: Many community-dwelling people with stroke did not receive any information, help or support after experiencing instability and falls. Clinicians must stress that falls are a complication, not an expectation, post-stroke. Information on falls prevention and available support services should be offered to individuals prior to discharge from hospital, in GP practices and in rehabilitation settings. All individuals with stroke seeking health professional help following instability and falls should be referred on to falls clinics for individualized multifactorial assessment and intervention to comply with current guidelines.

Poststroke Aphasia Frequency, Recovery, and Outcomes: A Systematic Review and Meta-Analysis.

PubMed

Flowers, Heather L; Skoretz, Stacey A; Silver, Frank L; Rochon, Elizabeth; Fang, Jiming; Flamand-Roze, Constance; Martino, Rosemary

2016-12-01

To conduct a systematic review to elucidate the frequency, recovery, and associated outcomes for poststroke aphasia over the long-term. Using the Cochrane Stroke Strategy, we searched 10 databases, 13 journals, 3 conferences, and the gray literature. Our a priori protocol criteria included unselected samples of adult stroke patients from randomized controlled trials or consecutive cohorts. Two independent reviewers rated abstracts and articles for exclusion or inclusion, resolving discrepancies by consensus. We documented aphasia frequencies by stroke type and setting, and computed odds ratios (ORs) with their 95% confidence intervals (CIs) for outcomes. We retrieved 2168 citations, reviewed 248 articles, and accepted 50. Median frequencies for mixed stroke (ischemic and hemorrhagic) were 30% and 34% for acute and rehabilitation settings, respectively. Frequencies by stroke type were lowest for acute subarachnoid hemorrhage (9%) and highest for acute ischemic stroke (62%) when arrival to the hospital was ≤3 hours from stroke onset. Articles monitoring aphasia for 1 year demonstrated aphasia frequencies 2% to 12% lower than baseline. Negative outcomes associated with aphasia included greater odds of in-hospital death (OR=2.7; 95% CI, 2.4-3.1) and longer mean length of stay in days (mean=1.6; 95% CI, 1.0-2.3) in acute settings. Patients with aphasia had greater disability from 28 days (OR=1.5; 95% CI, 1.3-1.7) to 2 years (OR=1.7; 95% CI, 1.6-2.0) than those without aphasia. By 2 years, they used more rehabilitation services (OR=1.5; 95% CI, 1.3-1.6) and returned home less frequently (OR=1.4; 95% CI, 1.2-1.7). Reported frequencies of poststroke aphasia range widely, depending on stroke type and setting. Because aphasia is associated with mortality, disability, and use of health services, we recommend long-term interdisciplinary vigilance in the management of aphasia. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Observed Cost and Variations in Short Term Cost-Effectiveness of Therapy for Ischemic Stroke in Interventional Management of Stroke (IMS) III.

PubMed

Simpson, Kit N; Simpson, Annie N; Mauldin, Patrick D; Palesch, Yuko Y; Yeatts, Sharon D; Kleindorfer, Dawn; Tomsick, Thomas A; Foster, Lydia D; Demchuk, Andrew M; Khatri, Pooja; Hill, Michael D; Jauch, Edward C; Jovin, Tudor G; Yan, Bernard; von Kummer, Rüdiger; Molina, Carlos A; Goyal, Mayank; Schonewille, Wouter J; Mazighi, Mikael; Engelter, Stefan T; Anderson, Craig; Spilker, Judith; Carrozzella, Janice; Ryckborst, Karla J; Janis, L Scott; Broderick, Joseph P

2017-05-08

Examination of linked data on patient outcomes and cost of care may help identify areas where stroke care can be improved. We report on the association between variations in stroke severity, patient outcomes, cost, and treatment patterns observed over the acute hospital stay and through the 12-month follow-up for subjects receiving endovascular therapy compared to intravenous tissue plasminogen activator alone in the IMS (Interventional Management of Stroke) III Trial. Prospective data collected for a prespecified economic analysis of the trial were used. Data included hospital billing records for the initial stroke admission and subsequent detailed resource use after the acute hospitalization collected at 3, 6, 9, and 12 months. Cost of follow-up care varied 6-fold for patients in the lowest (0-1) and highest (20+) National Institutes of Health Stroke Scale category at 5 days, and by modified Rankin Scale at 3 months. The kind of resources used postdischarge also varied between treatment groups. Incremental short-term cost-effectiveness ratios varied greatly when treatments were compared for patient subgroups. Patient subgroups predefined by stroke severity had incremental cost-effectiveness ratios of $97 303/quality-adjusted life year (severe stroke) and $3 187 805/quality-adjusted life year (moderately severe stroke). Detailed economic and resource utilization data from IMS III provide powerful evidence for the large effect that patient outcome has on the economic value of medical and endovascular reperfusion therapies. These data can be used to inform process improvements for stroke care and to estimate the cost-effectiveness of endovascular therapy in the US health system for stroke intervention trials. URL: http://www.clinicaltrials.gov. Registration number: NCT00359424. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Program to Diagnose Probability of Aspiration Pneumonia in Patients with Ischemic Stroke

PubMed Central

Pinto, Gisele; Zétola, Viviane; Lange, Marcos; Gomes, Guilherme; Nunes, Maria Cristina; Hirata, Gisela; Lagos-Guimarães, Hellen Nataly

2014-01-01

Introduction Stroke is a major cause of death and disability worldwide, with a strong economic and social impact. Approximately 40% of patients show motor, language, and swallowing disorders after stroke. Objective To evaluate the use of software to infer the probability of pneumonia in patients with ischemic stroke. Methods Prospective and cross-sectional study conducted in a university hospital from March 2010 to August 2012. After confirmation of ischemic stroke by computed axial tomography, a clinical and flexible endoscopic evaluation of swallowing was performed within 72 hours of onset of symptoms. All patients received speech therapy poststroke, and the data were subsequently analyzed by the software. The patients were given medical treatment and speech therapy for 3 months. Results The study examined 52 patients with a mean age of 62.05 ± 13.88 years, with 23 (44.2%) women. Of the 52 patients, only 3 (5.7%) had a probability of pneumonia between 80 and 100% as identified by the software. Of all patients, 32 (61.7%) had pneumonia probability between 0 and 19%, 5 (9.5%) between 20 and 49%, 3 (5.8%) between 50 and 79%, and 12 (23.0%) between 80 and 100%. Conclusion The computer program indicates the probability of patient having aspiration pneumonia after ischemic stroke. PMID:25992100

Rehabilitation for post-stroke cognitive impairment: an overview of recommendations arising from systematic reviews of current evidence.

PubMed

Gillespie, David C; Bowen, Audrey; Chung, Charlie S; Cockburn, Janet; Knapp, Peter; Pollock, Alex

2015-02-01

Although cognitive impairments are common following stroke, there is considerable uncertainty about the types of interventions that can reduce activity restrictions and improve quality of life. Indeed, a recent project to identify priorities for research into life after stroke determined that the top priority for patients, carers and health professionals was how to improve cognitive impairments. To provide an overview of the evidence for the effectiveness of cognitive rehabilitation for patients with stroke and to determine the main gaps in the current evidence base. Evidence was synthesised for the six Cochrane reviews relating to rehabilitation for post-stroke cognitive impairment and any subsequently published randomized controlled trials to February 2012. Data arising from 44 trials involving over 1500 patients was identified. Though there was support for the effectiveness of cognitive rehabilitation for some cognitive impairments, significant gaps were found in the current evidence base. All of the Cochrane reviews identified major limitations within the evidence they identified. There is currently insufficient research evidence, or evidence of insufficient quality, to support clear recommendations for clinical practice. Recommendations are made as to the research required to strengthen the evidence base, and so facilitate the delivery of effective interventions to individuals with cognitive impairment after stroke. © The Author(s) 2014.

Acute ischemic cerebrovascular events on antiplatelet therapy: what is the optimal prevention strategy?

PubMed

Milionis, Haralampos; Michel, Patrik

2013-01-01

Even though patients who develop ischemic stroke despite taking antiplatelet drugs represent a considerable proportion of stroke hospital admissions, there is a paucity of data from investigational studies regarding the most suitable therapeutic intervention. There have been no clinical trials to test whether increasing the dose or switching antiplatelet agents reduces the risk for subsequent events. Certain issues have to be considered in patients managed for a first or recurrent stroke while receiving antiplatelet agents. Therapeutic failure may be due to either poor adherence to treatment, associated co-morbid conditions and diminished antiplatelet effects (resistance to treatment). A diagnostic work up is warranted to identify the etiology and underlying mechanism of stroke, thereby guiding further management. Risk factors (including hypertension, dyslipidemia and diabetes) should be treated according to current guidelines. Aspirin or aspirin plus clopidogrel may be used in the acute and early phase of ischemic stroke, whereas in the long-term, antiplatelet treatment should be continued with aspirin, aspirin/extended release dipyridamole or clopidogrel monotherapy taking into account tolerance, safety, adherence and cost issues. Secondary measures to educate patients about stroke, the importance of adherence to medication, behavioral modification relating to tobacco use, physical activity, alcohol consumption and diet to control excess weight should also be implemented.

Clinical characteristics of patients with ischemic stroke following the 2016 Kumamoto earthquake.

PubMed

Inatomi, Yuichiro; Nakajima, Makoto; Yonehara, Toshiro; Ando, Yukio

2017-12-01

To investigate the clinical characteristics of patients with ischemic stroke following the 2016 Kumamoto earthquake. We retrospectively studied patients with ischemic stroke admitted to our hospital for 12weeks following the earthquake. We compared the clinical backgrounds and characteristics of the patients: before (the same period from the previous 3years) and after the earthquake; and the early (first 2weeks) and late (subsequent 10weeks) phases. A total of 194 patients with ischemic stroke were admitted to our hospital after the earthquake; 496 (165.3/year) patients were admitted before the earthquake. No differences between the two groups were noted for the clinical backgrounds, characteristics, or biomarkers. Past history of sleeping in a shelter or small vehicle was found in 13% and 28% of patients, respectively. Sleeping in a shelter (27% vs. 10%, p=0.013) was found more frequently in patients during the early phase than during the late phase after the earthquake. Admission of patients with ischemic stroke increased after the earthquake; however no differences between before and after the earthquake were noted for their clinical characteristics. To prevent ischemic stroke following earthquakes, mental stress and physical status of evacuees must be assessed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Retrieval Practice Fails to Insulate Episodic Memories against Interference after Stroke.

PubMed

Pastötter, Bernhard; Eberle, Hanna; Aue, Ingo; Bäuml, Karl-Heinz T

2017-01-01

Recent work in cognitive psychology showed that retrieval practice of previously studied information can insulate this information against retroactive interference from subsequently studied other information in healthy individuals. The present study examined whether this beneficial effect of interference reduction is also present in patients with stroke. Twenty-two patients with stroke, 4.6 months post injury on average, and 22 healthy controls participated in the experiment. In each of two experimental sessions, participants first studied a list of items (list 1) and then underwent a practice phase in which the list 1 items were either restudied or retrieval practiced. Participants then either studied a second list of items (list 2) or fulfilled an unrelated distractor task. Recall of the two lists' items was assessed in a final criterion test. Results showed that, in healthy controls, additional study of list 2 items impaired final recall of list 1 items in the restudy condition but not in the retrieval practice condition. In contrast, in patients with stroke, list 2 learning impaired final list 1 recall in both conditions. The results indicate that retrieval practice insulated the tested information against retroactive interference in healthy controls, but failed to do so in patients with stroke. Possible implications of the findings for the understanding of long-term memory impairment after stroke are discussed.

Diagnosis and initial management of cerebellar infarction.

PubMed

Edlow, Jonathan A; Newman-Toker, David E; Savitz, Sean I

2008-10-01

Cerebellar infarction is an important cause of stroke that often presents with common and non-specific symptoms such as dizziness, nausea and vomiting, unsteady gait, and headache. Accurate diagnosis frequently relies on careful attention to patients' coordination, gait, and eye movements--components of the neurological physical examination that are sometimes omitted or abridged if cerebellar stroke is not specifically being considered. The differential diagnosis is broad, and includes many common and benign causes. Furthermore, early-stage posterior fossa ischaemia is rarely seen with brain CT--the most commonly available initial imaging test that is used for stroke. Insufficient examination and imaging can result in misdiagnosis. However, early correct diagnosis is crucial to help prevent treatable but potentially fatal complications, such as brainstem compression and obstructive hydrocephalus. The identification and treatment of the underlying vascular lesions at an early stage can also prevent subsequent occurrences of stroke and improve patients' outcomes. Here, we review the clinical presentation of cerebellar infarction, from diagnosis and misdiagnosis to patients' monitoring, treatment, and potential complications.

Patient perceptions having suffered a stroke in Galway.

PubMed

Casey, Dympna; Murphy, Kathy; Cooney, Adeline; O'Shea, Eamon

2008-08-01

Of the estimated 10,000 people annually who have a stroke in Ireland, about 7500 will continue to live with some residual disability. This study explored older people's perceptions of health, level of independence as well as the factors that enhanced or diminished ability to maintain quality of life after stroke. A grounded theory approach was used and 20 stroke survivors were interviewed. Analysis of the data revealed three main themes: concepts of health and independence, sense of loss, and environmental factors. Despite their disability most participants continued to have a positive concept of health. Participants overall adopted a functional approach toward independence and those with severe disabilities felt less independent. Many reported a profound sense of loss in terms of identity and role function. Environmental factors including availability of transport and social connections had a significant impact on quality of life. Most participants appeared to be struggling to adapt to their disability and subsequent experiences in a rather unsupportive environment.

Process improvement methodologies uncover unexpected gaps in stroke care.

PubMed

Kuner, Anthony D; Schemmel, Andrew J; Pooler, B Dustin; Yu, John-Paul J

2018-01-01

Background The diagnosis and treatment of acute stroke requires timed and coordinated effort across multiple clinical teams. Purpose To analyze the frequency and temporal distribution of emergent stroke evaluations (ESEs) to identify potential contributory workflow factors that may delay the initiation and subsequent evaluation of emergency department stroke patients. Material and Methods A total of 719 sentinel ESEs with concurrent neuroimaging were identified over a 22-month retrospective time period. Frequency data were tabulated and odds ratios calculated. Results Of all ESEs, 5% occur between 01:00 and 07:00. ESEs were most frequent during the late morning and early afternoon hours (10:00-14:00). Unexpectedly, there was a statistically significant decline in the frequency of ESEs that occur at the 14:00 time point. Conclusion Temporal analysis of ESEs in the emergency department allowed us to identify an unexpected decrease in ESEs and through process improvement methodologies (Lean and Six Sigma) and identify potential workflow elements contributing to this observation.

Multiple recurrent ischaemic strokes in a patient with cancer: is there a role for the initiation of anticoagulation therapy for secondary stroke prevention?

PubMed Central

Suero-Abreu, Giselle Alexandra; Cheng, Jia Zhen; Then, Ryna Karina

2017-01-01

A 52-year-old woman with a medical history of cervical and thyroid cancer, hypertension, dyslipidaemia, uncontrolled diabetes and heavy smoking was diagnosed with a new metastatic cholangiocarcinoma. While undergoing palliative chemotherapy, she developed dysarthria and left-sided weakness. Imaging studies showed multiple bilateral ischaemic strokes. On hospital days 2 and 5, she developed worsening neurological symptoms and imaging studies revealed new areas of ischaemia on respective days. Subsequent workup did not revealed a clear aetiology for the multiple ischaemic events and hypercoagulability studies were only significant for a mildly elevated serum D-dimer level. Although guidelines are unclear, full-dose anticoagulation with low molecular weight heparin was initiated given her high risk of stroke recurrence. She was discharged to acute rehabilitation but, within a month, she experienced complications of her malignant disease progression and a new pulmonary thromboembolism. The patient died soon after being discharged home with hospice care. PMID:28578306

High-Speed Video Observations of a Natural Lightning Stepped Leader

NASA Astrophysics Data System (ADS)

Jordan, D. M.; Hill, J. D.; Uman, M. A.; Yoshida, S.; Kawasaki, Z.

2010-12-01

High-speed video images of one branch of a natural negative lightning stepped leader were obtained at a frame rate of 300 kfps (3.33 us exposure) on June 18th, 2010 at the International Center for Lightning Research and Testing (ICLRT) located on the Camp Blanding Army National Guard Base in north-central Florida. The images were acquired using a 20 mm Nikon lens mounted on a Photron SA1.1 high-speed camera. A total of 225 frames (about 0.75 ms) of the downward stepped leader were captured, followed by 45 frames of the leader channel re-illumination by the return stroke and subsequent decay following the ground attachment of the primary leader channel. Luminous characteristics of dart-stepped leader propagation in triggered lightning obtained by Biagi et al. [2009, 2010] and of long laboratory spark formation [e.g., Bazelyan and Raizer, 1998; Gallimberti et al., 2002] are evident in the frames of the natural lightning stepped leader. Space stems/leaders are imaged in twelve different frames at various distances in front of the descending leader tip, which branches into two distinct components 125 frames after the channel enters the field of view. In each case, the space stem/leader appears to connect to the leader tip above in the subsequent frame, forming a new step. Each connection is associated with significant isolated brightening of the channel at the connection point followed by typically three or four frames of upward propagating re-illumination of the existing leader channel. In total, at least 80 individual steps were imaged.

Telerehabilitation to improve outcomes for people with stroke: study protocol for a randomised controlled trial

PubMed Central

2012-01-01

Background In New Zealand, around 45,000 people live with stroke and many studies have reported that benefits gained during initial rehabilitation are not sustained. Evidence indicates that participation in physical interventions can prevent the functional decline that frequently occurs after discharge from acute care facilities. However, on-going stroke services provision following discharge from acute care is often related to non-medical factors such as availability of resources and geographical location. Currently most people receive no treatment beyond three months post stroke. The study aims to determine if the Augmented Community Telerehabilitation Intervention (ACTIV) results in better physical function for people with stroke than usual care, as measured by the Stroke Impact Scale, physical subcomponent. Methods/design This study will use a multi-site, two-arm, assessor blinded, parallel randomised controlled trial design. People will be eligible if they have had their first ever stroke, are over 20 and have some physical impairment in either arm or leg, or both. Following discharge from formal physiotherapy services (inpatient, outpatient or community), participants will be randomised into ACTIV or usual care. ACTIV uses readily available technology, telephone and mobile phones, combined with face-to-face visits from a physiotherapist over a six-month period, to help people with stroke resume activities they enjoyed before the stroke. The impact of stroke on physical function and quality of life will be assessed, measures of cost will be collected and a discrete choice survey will be used to measure preferences for rehabilitation options. These outcomes will be collected at baseline, six months and 12 months. In-depth interviews will be used to explore the experiences of people participating in the intervention arm of the study. Discussion The lack of on-going rehabilitation for people with stroke diminishes the chance of their best possible outcome and may contribute to a functional decline following discharge from formal rehabilitation. Best practice guidelines recommend a prolonged period of rehabilitation, however this is expensive and therefore not undertaken in most publicly funded centres. An effective, cost-effective, and preference-sensitive therapy using basic technology to assist programme delivery may improve patient autonomy as they leave formal rehabilitation and return home. Trial registration ACTRN12612000464864 PMID:23216861

The effect of recovery duration on running speed and stroke quality during intermittent training drills in elite tennis players.

PubMed

Ferrauti, A; Pluim, B M; Weber, K

2001-04-01

The aim of this study was to assess the effect of the recovery duration in intermittent training drills on metabolism and coordination in sport games. Ten nationally ranked male tennis players (age 25.3+/-3.7 years, height 1.83+/-0.8 m, body mass 77.8+/-7.7 kg; mean +/- sx) participated in a passing-shot drill (baseline sprint with subsequent passing shot) that aimed to improve both starting speed and stroke quality (speed and precision). Time pressure for stroke preparation was individually adjusted by a ball-machine and corresponded to 80% of maximum running speed. In two trials (T10, T15) separated by 2 weeks, the players completed 30 strokes and sprints subdivided into 6 x 5 repetitions with a 1 min rest between series. The rest between each stroke-and-sprint lasted either 10 s (T10) or 15 s (T15). The sequence of both conditions was randomized between participants. Post-exercise blood lactate concentration was significantly elevated in T10 (9.04+/-3.06 vs 5.01+/-1.35 mmol x l(-1), P < 0.01). Running time for stroke preparation (1.405+/-0.044 vs 1.376+/-0.045 s, P < 0.05) and stroke speed (106+/-12 vs 114+/-8 km x h(-1), P < 0.05) were significantly decreased in T10, while stroke precision - that is, more target hits (P < 0.1) and fewer errors (P < 0.05) - tended to be higher. We conclude that running speed and stroke quality during intermittent tennis drills are highly dependent on the duration of recovery time. Optimization of training efficacy in sport games (e.g. combined improvement of conditional and technical skills) requires skilful fine-tuning of monitoring guidelines.

Chickenpox and Risk of Stroke: A Self-controlled Case Series Analysis

PubMed Central

Thomas, Sara L.; Minassian, Caroline; Ganesan, Vijeya; Langan, Sinéad M.; Smeeth, Liam

2014-01-01

Background. There is good evidence that respiratory and other infections that cause systemic inflammation can trigger strokes; however, the role of specific infections is unclear. Case reports have highlighted chickenpox as a possible risk factor for arterial ischemic stroke, particularly in children, but rigorous studies are needed to determine and quantify any increased risk. Methods. We used anonymized electronic health records totaling >100 million person-years of observation from 4 UK primary care databases to identify individuals who had documented clinical chickenpox and a stroke or transient ischemic attack (TIA). Self-controlled case series methods were used to quantify any increased risk of first stroke or TIA in the 0–6 and 7–12 months following chickenpox compared to other observed time periods. We analyzed data within each database, and performed meta-analyses to obtain summary age-adjusted incidence ratios (IRs) separately for adults and children. Results. Five hundred sixty eligible individuals (including 60 children) were identified who experienced chickenpox and a stroke or TIA during follow-up. Among children, there was a 4-fold increased risk of stroke in the 0–6 months after chickenpox (summary IR = 4.07; 95% confidence interval [CI], 1.96–8.45; I2 = 0%). Among adults, there was a less marked increased risk with moderate between-database heterogeneity (random-effects summary IR = 2.13; 95% CI, 1.05–4.36; I2 = 51%). There was no significant increased risk of stroke in the 7–12 months after chickenpox in children or adults, nor was there evidence of increased risk of TIA in either time period. Conclusions. Our study provides new evidence that children who experience chickenpox are at increased risk of stroke in the subsequent 6 months. PMID:24092802

Chickenpox and risk of stroke: a self-controlled case series analysis.

PubMed

Thomas, Sara L; Minassian, Caroline; Ganesan, Vijeya; Langan, Sinéad M; Smeeth, Liam

2014-01-01

There is good evidence that respiratory and other infections that cause systemic inflammation can trigger strokes; however, the role of specific infections is unclear. Case reports have highlighted chickenpox as a possible risk factor for arterial ischemic stroke, particularly in children, but rigorous studies are needed to determine and quantify any increased risk. We used anonymized electronic health records totaling >100 million person-years of observation from 4 UK primary care databases to identify individuals who had documented clinical chickenpox and a stroke or transient ischemic attack (TIA). Self-controlled case series methods were used to quantify any increased risk of first stroke or TIA in the 0-6 and 7-12 months following chickenpox compared to other observed time periods. We analyzed data within each database, and performed meta-analyses to obtain summary age-adjusted incidence ratios (IRs) separately for adults and children. Five hundred sixty eligible individuals (including 60 children) were identified who experienced chickenpox and a stroke or TIA during follow-up. Among children, there was a 4-fold increased risk of stroke in the 0-6 months after chickenpox (summary IR = 4.07; 95% confidence interval [CI], 1.96-8.45; I(2) = 0%). Among adults, there was a less marked increased risk with moderate between-database heterogeneity (random-effects summary IR = 2.13; 95% CI, 1.05-4.36; I(2) = 51%). There was no significant increased risk of stroke in the 7-12 months after chickenpox in children or adults, nor was there evidence of increased risk of TIA in either time period. Our study provides new evidence that children who experience chickenpox are at increased risk of stroke in the subsequent 6 months.

Decline in physical performance among women with a recent transient ischemic attack or ischemic stroke: opportunities for functional preservation a report of the Women's Estrogen Stroke Trial.

PubMed

Kernan, Walter N; Viscoli, Catherine M; Brass, Lawrence M; Gill, Thomas M; Sarrel, Philip M; Horwitz, Ralph I

2005-03-01

Physical performance for walking, reaching, turning, and other common tasks is a major determinant of functional independence after stroke. Current strategies to preserve physical performance focus on prevention of recurrent stroke. Loss of physical performance, however, may occur in the absence of recurrence. To examine this possibility, we measured change in physical performance, independent of subsequent stroke, among women with a recent ischemic stroke or transient ischemic attack (TIA). Among 664 postmenopausal women who participated in a clinical trial of estrogen therapy after stroke or TIA, we administered the Physical Performance Test (PPT) at baseline (mean 58 days from the cerebrovascular event) and annually. Women who died or had a stroke during follow-up were censored. Decline or improvement in physical performance was defined as a change in the PPT score from baseline of at least 3 points. Sustained decline or improvement was defined as 2 consecutive years during which the score had declined or improved, respectively, relative to the baseline score. With each year of follow-up, a smaller proportion of the cohort demonstrated improvement (16% in year 1, 6% in year 5) and a larger proportion demonstrated decline (15% in year 1, 35% in year 5). In an analysis restricted to 259 women with 3 years of follow-up, 46 (18%) experienced a nonsustained decline in physical performance, and 39 (15%) experienced a sustained decline. Decline in physical performance is common after an ischemic stroke or TIA even in the absence of a recurrent neurological event. Our findings suggest that specific interventions to maintain and improve physical performance may be important for reducing long-term disability.

Quantifying Selection Bias in National Institute of Health Stroke Scale Data Documented in an Acute Stroke Registry.

PubMed

Thompson, Michael P; Luo, Zhehui; Gardiner, Joseph; Burke, James F; Nickles, Adrienne; Reeves, Mathew J

2016-05-01

As a measure of stroke severity, the National Institutes of Health Stroke Scale (NIHSS) is an important predictor of patient- and hospital-level outcomes, yet is often undocumented. The purpose of this study is to quantify and correct for potential selection bias in observed NIHSS data. Data were obtained from the Michigan Stroke Registry and included 10 262 patients with ischemic stroke aged ≥65 years discharged from 23 hospitals from 2009 to 2012, of which 74.6% of patients had documented NIHSS. We estimated models predicting NIHSS documentation and NIHSS score and used the Heckman selection model to estimate a correlation coefficient (ρ) between the 2 model error terms, which quantifies the degree of selection bias in the documentation of NIHSS. The Heckman model found modest, but significant, selection bias (ρ=0.19; 95% confidence interval: 0.09, 0.29; P<0.001), indicating that because NIHSS score increased (ie, strokes were more severe), the probability of documentation also increased. We also estimated a selection bias-corrected population mean NIHSS score of 4.8, which was substantially lower than the observed mean NIHSS score of 7.4. Evidence of selection bias was also identified using hospital-level analysis, where increased NIHSS documentation was correlated with lower mean NIHSS scores (r=-0.39; P<0.001). We demonstrate modest, but important, selection bias in documented NIHSS data, which are missing more often in patients with less severe stroke. The population mean NIHSS score was overestimated by >2 points, which could significantly alter the risk profile of hospitals treating patients with ischemic stroke and subsequent hospital risk-adjusted outcomes. © 2016 American Heart Association, Inc.

P-wave morphology and the risk of incident ischemic stroke in the Multi-Ethnic Study of Atherosclerosis.

PubMed

Kamel, Hooman; Soliman, Elsayed Z; Heckbert, Susan R; Kronmal, Richard A; Longstreth, W T; Nazarian, Saman; Okin, Peter M

2014-09-01

Emerging data suggest that left atrial disease may cause ischemic stroke in the absence of atrial fibrillation or flutter (AF). If true, this condition may provide a cause for many strokes currently classified as cryptogenic. Among 6741 participants in the Multi-Ethnic Study of Atherosclerosis who were free of clinically apparent cerebrovascular or cardiovascular disease (including AF) at baseline, we examined the association between markers of left atrial abnormality on a standard 12-lead ECG-specifically P-wave area, duration, and terminal force in lead V1-and the subsequent risk of ischemic stroke while accounting for incident AF. During a median follow-up of 8.5 years, 121 participants (1.8%) had a stroke and 541 participants (8.0%) were diagnosed with AF. In Cox proportional hazards models adjusting for potential baseline confounders, P-wave terminal force in lead V1 was more strongly associated with incident stroke (hazard ratio per 1 SD increase, 1.21; 95% confidence interval, 1.02-1.44) than with incident AF (hazard ratio per 1 SD, 1.11; 95% confidence interval, 1.03-1.21). The association between P-wave terminal force in lead V1 and stroke was robust in numerous sensitivity analyses accounting for AF, including analyses that excluded those with any incident AF or modeled any incident AF as having been present from baseline. We found an association between baseline P-wave morphology and incident stroke even after accounting for AF. This association may reflect an atrial cardiopathy that leads to stroke in the absence of AF. © 2014 American Heart Association, Inc.

Disparities in adult African American women's knowledge of heart attack and stroke symptomatology: an analysis of 2003-2005 Behavioral Risk Factor Surveillance Survey data.

PubMed

Lutfiyya, May Nawal; Cumba, Marites T; McCullough, Joel Emery; Barlow, Erika Laverne; Lipsky, Martin S

2008-06-01

Heart disease and stroke are the first and third leading causes of death of American women, respectively. African American women experience a disproportionate burden of these diseases compared with Caucasian women and are also more likely to delay seeking treatment for acute symptoms. As knowledge is a first step in seeking care, this study examined the knowledge of heart attack and stroke symptoms among African American women. This was a cross-sectional study analyzing 2003-2005 Behavioral Risk Factor Surveillance Survey (BRFSS) data. A composite heart attack and stroke knowledge score was computed for each respondent from the 13 heart attack and stroke symptom knowledge questions. Multivariate logistic regression was performed using low scores on the heart attack and stroke knowledge questions as the dependent variable. Twenty percent of the respondents were low scorers, and 23.8% were high scorers. Logistic regression analysis showed that adult African American women who earned low scores on the composite heart attack and stroke knowledge questions (range 0-8 points) were more likely to be aged 18-34 (OR = 1.36, CI 1.35, 1.37), be uninsured (OR = 1.32, CI 1.31, 1.33), have an annual household income <$35,000 (OR = 1.46, CI 1.45, 1.47), and have a primary healthcare provider (OR = 1.22, CI 1.20, 1.23). The findings indicated that knowledge of heart attack and stroke symptoms varied significantly among African American women, depending on socioeconomic variables. Targeting interventions to African American women, particularly those in lower socioeconomic groups, may increase knowledge of heart attack and stroke symptoms, subsequently improving preventive action taken in response to these conditions.

Development of a decision analytic model to support decision making and risk communication about thrombolytic treatment.

PubMed

McMeekin, Peter; Flynn, Darren; Ford, Gary A; Rodgers, Helen; Gray, Jo; Thomson, Richard G

2015-11-11

Individualised prediction of outcomes can support clinical and shared decision making. This paper describes the building of such a model to predict outcomes with and without intravenous thrombolysis treatment following ischaemic stroke. A decision analytic model (DAM) was constructed to establish the likely balance of benefits and risks of treating acute ischaemic stroke with thrombolysis. Probability of independence, (modified Rankin score mRS ≤ 2), dependence (mRS 3 to 5) and death at three months post-stroke was based on a calibrated version of the Stroke-Thrombolytic Predictive Instrument using data from routinely treated stroke patients in the Safe Implementation of Treatments in Stroke (SITS-UK) registry. Predictions in untreated patients were validated using data from the Virtual International Stroke Trials Archive (VISTA). The probability of symptomatic intracerebral haemorrhage in treated patients was incorporated using a scoring model from Safe Implementation of Thrombolysis in Stroke-Monitoring Study (SITS-MOST) data. The model predicts probabilities of haemorrhage, death, independence and dependence at 3-months, with and without thrombolysis, as a function of 13 patient characteristics. Calibration (and inclusion of additional predictors) of the Stroke-Thrombolytic Predictive Instrument (S-TPI) addressed issues of under and over prediction. Validation with VISTA data confirmed that assumptions about treatment effect were just. The C-statistics for independence and death in treated patients in the DAM were 0.793 and 0.771 respectively, and 0.776 for independence in untreated patients from VISTA. We have produced a DAM that provides an estimation of the likely benefits and risks of thrombolysis for individual patients, which has subsequently been embedded in a computerised decision aid to support better decision-making and informed consent.

Safety of a "drip and ship" intravenous thrombolysis protocol for patients with acute ischemic stroke.

PubMed

Mansoor, Simin; Zand, Ramin; Al-Wafai, Ameer; Wahba, Mervat N; Giraldo, Elias A

2013-10-01

The "drip and ship" approach for intravenous thrombolysis (IVT) is becoming the standard of care for patients with acute ischemic stroke (AIS) in communities without direct access to a stroke specialist. We aimed to demonstrate the safety of our "drip and ship" IVT protocol. This was a retrospective study of patients with AIS treated with IVT between January 2003 and January 2011. Information on patients' baseline characteristics, neuroimaging, symptomatic intracerebral hemorrhage (sICH), and mortality was obtained from our stroke registry. A group of patients were treated with IVT by an emergency physician in phone consultation with a board-certified vascular neurologist (BCVN) at 1 of our 3 stroke network-affiliated hospitals (SNAHs). These patients were subsequently transferred to our Joint Commission-certified primary stroke center (CPSC) after completion of IVT ("drip and ship" protocol). The other patients were treated directly by a BCVN at the CPSC. We studied 201 patients treated with IVT. Of them, 14% received IVT at a SNAH ("drip and ship" protocol) and 86% were treated at the CPSC. There were no significant differences between the 2 groups with regard to age, National Institutes of Health Stoke Scale score, stroke symptom onset-to-needle time, sICH, or in-hospital mortality. Our "drip and ship" protocol for IVT is safe. The protocol was not associated with an excess of sICH or in-hospital mortality compared with patients who received IVT at the CPSC. Copyright © 2013 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) Trial: rationale and design

PubMed Central

Johnston, S. Claiborne; Easton, J. Donald; Farrant, Mary; Barsan, William; Battenhouse, Holly; Conwit, Robin; Dillon, Catherine; Elm, Jordan; Lindblad, Anne; Morgenstern, Lewis; Poisson, Sharon N.; Palesch, Yuko

2015-01-01

Background Ischemic stroke and other vascular outcomes occur in 10–20% of patients in the 3 months following a TIA or minor ischemic stroke, and many are disabling. The highest risk period for these outcomes is the early hours and days immediately following the ischemic event. Aspirin is the most common antithrombotic treatment used for these patients. Aim The aim of POINT is to determine whether clopidogrel plus aspirin taken <12 hours after TIA or minor ischemic stroke symptom onset is more effective in preventing major ischemic vascular events at 90 days in the high-risk, and acceptably safe, compared to aspirin alone. Design POINT is a prospective, randomized, double-blind, multicenter trial in patients with TIA or minor ischemic stroke. Subjects are randomized to clopidogrel (600 mg loading dose followed by 75 mg/day) or matching placebo, and all will receive open-label aspirin 50–325 mg/day, with a dose of 162 mg daily for 5 days followed by 81 mg daily strongly recommended. Study Outcomes The primary efficacy outcome is the composite of new ischemic vascular events: ischemic stroke, myocardial infarction or ischemic vascular death, by 90 days. The primary safety outcome is major hemorrhage, which includes symptomatic intracranial hemorrhage. Discussion Aspirin is the most common antithrombotic given to patients with a stroke or TIA as it reduces the risk subsequent of stroke. This trial expects to determine whether more aggressive antithrombotic therapy with clopidogrel plus aspirin, initiated acutely, is more effective than aspirin alone. PMID:23879752

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

Novel insight into circular RNA HECTD1 in astrocyte activation via autophagy by targeting MIR142-TIPARP: Implications for cerebral ischemic stroke.

PubMed

Han, Bing; Zhang, Yuan; Zhang, Yanhong; Bai, Ying; Chen, Xufeng; Huang, Rongrong; Wu, Fangfang; Leng, Shuo; Chao, Jie; Zhang, John H; Hu, Gang; Yao, Honghong

2018-06-25

Circular RNAs (circRNAs) are highly expressed in the central nervous system and are involved in the regulation of physiological and pathophysiological processes. However, the potential role of circRNAs in stroke remains largely unknown. Here, using a circRNA microarray, we showed that circular RNA Hectd1 (circHectd1) levels were significantly increased in ischemic brain tissues in transient middle cerebral artery occlusion (tMCAO) mouse stroke models and further validated this finding in plasma samples from acute ischemic stroke (AIS) patients. Knockdown of circHectd1 expression significantly decreased infarct areas, attenuated neuronal deficits, and ameliorated astrocyte activation in tMCAO mice. Mechanistically, circHECTD1 functions as an endogenous MIR142 (microRNA 142) sponge to inhibit MIR142 activity, resulting in the inhibition of TIPARP (TCDD inducible poly[ADP-ribose] polymerase) expression with subsequent inhibition of astrocyte activation via macroautophagy/autophagy. Taken together, the results of our study indicate that circHECTD1 and its coupling mechanism are involved in cerebral ischemia, thus providing translational evidence that circHECTD1 can serve as a novel biomarker of and therapeutic target for stroke.

Cultural adaptation and validation of Stroke Impact Scale 3.0 version in Uganda: A small-scale study

PubMed Central

Kamwesiga, Julius T; von Koch, Lena; Kottorp, Anders; Guidetti, Susanne

2016-01-01

Background: Knowledge is scarce about the impact of stroke in Uganda, and culturally adapted, psychometrically tested patient-reported outcome measures are lacking. The Stroke Impact Scale 3.0 is recommended, but it has not been culturally adapted and validated in Uganda. Objective: To culturally adapt and determine the psychometric properties of the Stroke Impact Scale 3.0 in the Ugandan context on a small scale. Method: The Stroke Impact Scale 3.0 was culturally adapted to form Stroke Impact Scale 3.0 Uganda (in English) by involving 25 participants in three different expert committees. Subsequently, Stroke Impact Scale 3.0 Uganda from English to Luganda language was done in accordance with guidelines. The first language in Uganda is English and Luganda is the main spoken language in Kampala city and its surroundings. Translation of Stroke Impact Scale 3.0 Uganda (both in English and Luganda) was then tested psychometrically by applying a Rasch model on data collected from 95 participants with stroke. Results: Overall, 10 of 59 (17%) items in the eight domains of the Stroke Impact Scale 3.0 were culturally adapted. The majority were 6 of 10 items in the domain Activities of Daily Living, 2 of 9 items in the domain Mobility, and 2 of 5 items in the domain Hand function. Only in two domains, all items demonstrated acceptable goodness of fit to the Rasch model. There were also more than 5% person misfits in the domains Participation and Emotion, while the Communication, Mobility, and Hand function domains had the lowest proportions of person misfits. The reliability coefficient was equal or larger than 0.90 in all domains except the Emotion domain, which was below the set criterion of 0.80 (0.75). Conclusion: The cultural adaptation and translation of Stroke Impact Scale 3.0 Uganda provides initial evidence of validity of the Stroke Impact Scale 3.0 when used in this context. The results provide support for several aspects of validity and precision but also point out issues for further adaptation and improvement of the Stroke Impact Scale. PMID:27746913

Cultural adaptation and validation of Stroke Impact Scale 3.0 version in Uganda: A small-scale study.

PubMed

Kamwesiga, Julius T; von Koch, Lena; Kottorp, Anders; Guidetti, Susanne

2016-01-01

Knowledge is scarce about the impact of stroke in Uganda, and culturally adapted, psychometrically tested patient-reported outcome measures are lacking. The Stroke Impact Scale 3.0 is recommended, but it has not been culturally adapted and validated in Uganda. To culturally adapt and determine the psychometric properties of the Stroke Impact Scale 3.0 in the Ugandan context on a small scale. The Stroke Impact Scale 3.0 was culturally adapted to form Stroke Impact Scale 3.0 Uganda ( in English ) by involving 25 participants in three different expert committees. Subsequently, Stroke Impact Scale 3.0 Uganda from English to Luganda language was done in accordance with guidelines. The first language in Uganda is English and Luganda is the main spoken language in Kampala city and its surroundings. Translation of Stroke Impact Scale 3.0 Uganda ( both in English and Luganda ) was then tested psychometrically by applying a Rasch model on data collected from 95 participants with stroke. Overall, 10 of 59 (17%) items in the eight domains of the Stroke Impact Scale 3.0 were culturally adapted. The majority were 6 of 10 items in the domain Activities of Daily Living, 2 of 9 items in the domain Mobility, and 2 of 5 items in the domain Hand function. Only in two domains, all items demonstrated acceptable goodness of fit to the Rasch model. There were also more than 5% person misfits in the domains Participation and Emotion, while the Communication, Mobility, and Hand function domains had the lowest proportions of person misfits. The reliability coefficient was equal or larger than 0.90 in all domains except the Emotion domain, which was below the set criterion of 0.80 (0.75). The cultural adaptation and translation of Stroke Impact Scale 3.0 Uganda provides initial evidence of validity of the Stroke Impact Scale 3.0 when used in this context. The results provide support for several aspects of validity and precision but also point out issues for further adaptation and improvement of the Stroke Impact Scale.

Is blood pressure control for stroke prevention the correct goal? The lost opportunity of preventing hypertension.

PubMed

Howard, George; Banach, Maciej; Cushman, Mary; Goff, David C; Howard, Virginia J; Lackland, Daniel T; McVay, Jim; Meschia, James F; Muntner, Paul; Oparil, Suzanne; Rightmyer, Melanie; Taylor, Herman A

2015-06-01

Although pharmacological treatment of hypertension has important health benefits, it does not capture the benefit of maintenance of ideal health through the prevention or delay of hypertension. A total of 26 875 black and white participants aged 45+ years were assessed and followed for incident stroke events. The association was assessed between incident stroke and: (1) systolic blood pressure (SBP)categorized as normal (<120 mm Hg), prehypertension (120-139 mm Hg), stage 1 hypertension (140-159 mm Hg), and stage 2 hypertension (160 mm Hg+), and (2) number of classes of antihypertensive medications, classified as none, 1, 2, or 3 or more. During 6.3 years of follow-up, 823 stroke events occurred. Nearly half (46%) of the population were successfully treated (SBP<140 mm Hg) hypertensives. Within blood pressure strata, the risk of stroke increased with each additional class of required antihypertensive medication, with hazard ratio [HR], 1.33; 95% confidence interval, 1.16 to 1.52 for normotensive, HR, 1.15; 95% confidence interval, 1.05 to 1.26 for prehypertension, and HR, 1.22; 95% confidence interval, 1.06 to 1.39 for stage 1 hypertension. A successfully treated (SBP<120 mm Hg) hypertensive person on 3+ antihypertensive medication classes was at marginally higher stroke risk than a person with untreated stage 1 hypertension (HR, 2.48 versus HR=2.19; relative to those with SBP <120 on no antihypertensive medications). Maintaining the normotensive status solely through pharmacological treatment has a profound impact, as nearly half of this general population cohort were treated to guideline (SBP<140 mm Hg) but failed to return to risk levels similar to normotensive individuals. Even with successful treatment, there is a substantial potential gain by prevention or delay of hypertension. © 2015 American Heart Association, Inc.

Effects of ischemic stroke on dynamics of cerebral autoregulation

NASA Astrophysics Data System (ADS)

Chen, Zhi; Ivanov, Plamen Ch; Hu, Kun; Stanley, Eugene; Novak, Vera

2004-03-01

Cerebral vasoregulation involves several complex mechanisms adapting blood flow to fluctuations of systemic blood pressure (BP). Autonomic BP and metabolic vasoregulation are impaired after stroke and cerebral blood flow depends on systemic BP. To probe the mechanisms of cerebral autoregulation we study levels of nonlinear synchronization between cerebral blood flow velocity (BFV) and peripheral BP. We quantify the instantaneous phase of each signal employing analytic signal approach and Hilbert transform. As a marker of synchronization, we introduce a measure of cross-correlation between the instantaneous phase increments of the BFV and BP signals at different time lags. We have studied 12 subjects with minor chronic ischemic stroke and 11 matched normotensive controls (age<65years). BFV and BP of these subjects are continuously recorded during supine baseline, head-up tilt, hyperventilation and CO2 rebreathing. For control subjects we find significant synchronization between cerebral BFV and peripheral BP only for short time lags of up to 5-6 seconds, suggesting a rapid return to a steady cerebral blood flow after initial blood pressure perturbations. In contrast, for stroke subjects BFV/BP we find enhanced synchronization over longer time lags of up to 20 seconds, suggesting entrainment of cerebral blood flow velocity by slow vasomotor rhythms. These findings suggest that cerebral vasoregulation is impaired and cerebral blood flow follows the fluctuations of systemic BP in a synchronous manner. Our analysis shows that cerebral autoregulation is impaired in 10 out of the 12 stroke subjects, which is typically difficult to diagnose with conventional methods. Thus, our novel synchronization approach offers a new tool sensitive for evaluation of changes in the dynamics of cerebral autoregulation under stroke.

Early supported discharge following mild stroke: a qualitative study of patients' and their partners' experiences of rehabilitation at home.

PubMed

Lou, Stina; Carstensen, Kathrine; Møldrup, Marie; Shahla, Seham; Zakharia, Elias; Nielsen, Camilla Palmhøj

2017-06-01

Early supported discharge (ESD) allows mild-to-moderate stroke patients to return home as soon as possible and continue rehabilitation at their own pace in familiar surroundings. Thus, the main responsibility for continued rehabilitation is in the hands of patients and their partners, who must collaborate to adjust to poststroke everyday life. However, couples' joint experiences of stroke, early discharge and rehabilitation at home remain minimally investigated. To investigate how mild stroke patients' and their partners' experience and manage everyday life in a context of ESD. We conducted qualitative interviews with a purposive sample of 22 ESD patients and 18 partners. Interviews were conducted 3-6 weeks after stroke, and we used thematic analysis to analyse the data. The analysis identified three themes. First, 'Home as a healing place' involved the couples' experiences of a well-informed discharge from hospital. They trusted the health professionals' assessment that the patient was ready to go home. They described home as a comforting and calm place, where recovery could meaningfully take place. The second theme, 'Flow of everyday life', comprised the experiences of adapting to and continuing everyday life. Most of the interviewees had relatively minor physical and cognitive impairments, and the patients and their partners were hopeful for a full recovery in the foreseeable future. Finally, 'Professional safety net' involved the much appreciated stroke team. Although most of the participants only had one visit from the team, knowing that they were an accessible resource was very important to the couples. ESD was experienced as a meaningful and adequate rehabilitation service that allowed patients and partners to collaboratively reinvent and rebuild their flow of everyday life by jointly adjusting routines, activities and their relationship. © 2016 Nordic College of Caring Science.

Thrombolytic Treatment for Ischaemic Stroke: Could the Crisis of Confidence Have Been Avoided by Better Analysis of Trial Data?

PubMed

Barer, David; Berge, Eivind

2017-02-01

In many countries, thrombolysis with intravenous alteplase has become a central part of acute stroke care in recent years, requiring radical restructuring of services. However, a significant minority of emergency and stroke physicians have always had serious doubts about the safety and efficacy of thrombolytic treatment, and in 2015 these prompted a major review of the licensing status of alteplase by the UK regulatory authorities. Subsequent dramatic headlines and media stories have called into question the integrity of researchers and clinicians and undermined public faith in medical research. How did this situation arise and what should be done to prevent a repetition as we enter the era of intra-arterial treatment for stroke?Early intravenous alteplase increases the chances both of good recovery and of severe haemorrhage, so the risk/benefit balance must be assessed for individual patients according to stroke severity. For older patients and those with bigger strokes, the 'good recovery' criterion is an inefficient way of assessing treatment effects since few achieve full independence and differences between levels of functional impairment are ignored. This waste of information can be reduced by applying different criteria for 'good' and 'poor' outcomes in different prognostic groups (as clinicians do intuitively), hence increasing the number of patients contributing useful data. Such 'three-way prognosis-based outcome' analysis of existing and future trials could greatly increase the amount of relevant evidence to guide clinical decisions for individual patients across the range of stroke severity.

Prospective quality initiative to maximize dysphagia screening reduces hospital-acquired pneumonia prevalence in patients with stroke.

PubMed

Titsworth, W Lee; Abram, Justine; Fullerton, Amy; Hester, Jeannette; Guin, Peggy; Waters, Michael F; Mocco, J

2013-11-01

Dysphagia can lead to pneumonia and subsequent death after acute stroke. However, no prospective study has demonstrated reduced pneumonia prevalence after implementation of a dysphagia screen. We performed a single-center prospective interrupted time series trial of a quality initiative to improve dysphagia screening. Subjects included all patients with ischemic or hemorrhagic stroke admitted to our institution over 42 months with a 31-month (n=1686) preintervention and an 11-month (n=648) postintervention period. The intervention consisted of a dysphagia protocol with a nurse-administered bedside dysphagia screen and a reflexive rapid clinical swallow evaluation by a speech pathologist. The dysphagia initiative increased the percentage of patients with stroke screened from 39.3% to 74.2% (P<0.001). Furthermore, this initiative coincided with a drop in hospital-acquired pneumonia from 6.5% to 2.8% among patients with stroke (P<0.001). Patients admitted postinitiative had 57% lower odds of pneumonia, after controlling for multiple confounds (odds ratio=0.43; confidence interval, 0.255-0.711; P=0.0011). The best predictors of pneumonia were stroke type (P<0.0001), oral intake status (P<0.0001), dysphagia screening status (P=0.0037), and hospitalization before the beginning of the quality improvement initiative (P=0.0449). A quality improvement initiative using a nurse-administered bedside screen with rapid bedside swallow evaluation by a speech pathologist improves screening compliance and correlates with decreased prevalence of pneumonia among patients with stroke.

Factors Associated With Gastrostomy Tube Removal in Patients With Dysphagia After Stroke.

PubMed

Wilmskoetter, Janina; Herbert, Teri Lynn; Bonilha, Heather S

2017-04-01

Gastrostomy feeding tubes are commonly placed in patients with dysphagia after stroke. The subsequent removal of the tube is a primary goal during rehabilitation. The purpose of our review was to identify predictors and factors associated with gastrostomy tube removal in patients with dysphagia after stroke. We conducted a literature review following the PRISMA statement and included the search databases PubMed, Scopus, Web of Science, and CINAHL. Articles were included in the final analysis per predefined inclusion and exclusion criteria. Our search retrieved a total of 853 results consisting of 416 articles (after eliminating duplicates). Six articles met our final eligibility criteria. The following factors were identified in at least 1 article as being significantly associated with gastrostomy tube removal: reduced age, decreased number of comorbidities, prolonged inpatient rehabilitation stay, absence of bilateral stroke, nonhemorrhagic stroke, reduced dysphagia severity, absence of aspiration, absence of premature bolus loss, and timely initiation of pharyngeal swallow. Aspiration was the only factor that was investigated by 2 studies-both using multiple regression and both showing stable results, with absence of aspiration increasing the chances for tube removal. In conclusion, little is known about factors associated with gastrostomy tube removal in patients with dysphagia after stroke. Most of the identified factors are associated with stroke or disease severity; however, the role of the individual factors remains unclear. The strongest predictor appears to be absence of aspiration on modified barium swallow studies emphasizing the importance of instrumental swallow studies in this patient population.

Database Design for the Evaluation of On-shore and Off-Shore Storm Characteristics over East Central Florida

NASA Technical Reports Server (NTRS)

Simpson, Amy A.; Wilson, Jennifer G.; Brown, Robert G.

2015-01-01

Data from multiple sources is needed to investigate lightning characteristics over differing terrain (on-shore vs. off-shore) by comparing natural cloud-to-ground lightning behavior differences depending on the characteristics of attachment mediums. The KSC Lightning Research Database (KLRD) was created to reduce manual data entry time and aid research by combining information from various data sources into a single record for each unique lightning event of interest. The KLRD uses automatic data handling functions to import data from a lightning detection network and identify and record lighting events of interest. Additional automatic functions import data from the NASA Buoy 41009 (located approximately 20 miles off the coast) and the KSC Electric Field Mill network, then match these electric field mill values to the corresponding lightning events. The KLRD calculates distances between each lightning event and the various electric field mills, aids in identifying the location type for each stroke (i.e., on-shore vs. off-shore, etc.), provides statistics on the number of strokes per flash, and produces customizable reports for quick retrieval and logical display of data. Data from February 2014 to date covers 48 unique storm dates with 2295 flashes containing 5700 strokes, of which 2612 are off-shore and 1003 are on-shore. The number of strokes per flash ranges from 1 to 22. The ratio of single to subsequent stroke flashes is 1.29 for off-shore strokes and 2.19 for on-shore strokes.

Risk Factors For Stroke, Myocardial Infarction, or Death Following Carotid Endarterectomy: Results From the International Carotid Stenting Study.

PubMed

Doig, D; Turner, E L; Dobson, J; Featherstone, R L; de Borst, G J; Stansby, G; Beard, J D; Engelter, S T; Richards, T; Brown, M M

2015-12-01

Carotid endarterectomy (CEA) is standard treatment for symptomatic carotid artery stenosis but carries a risk of stroke, myocardial infarction (MI), or death. This study investigated risk factors for these procedural complications occurring within 30 days of endarterectomy in the International Carotid Stenting Study (ICSS). Patients with recently symptomatic carotid stenosis >50% were randomly allocated to endarterectomy or stenting. Analysis is reported of patients in ICSS assigned to endarterectomy and limited to those in whom CEA was initiated. The occurrence of stroke, MI, or death within 30 days of the procedure was reported by investigators and adjudicated. Demographic and technical risk factors for these complications were analysed sequentially in a binomial regression analysis and subsequently in a multivariable model. Eight-hundred and twenty-one patients were included in the analysis. The risk of stroke, MI, or death within 30 days of CEA was 4.0%. The risk was higher in female patients (risk ratio [RR] 1.98, 95% CI 1.02-3.87, p = .05) and with increasing baseline diastolic blood pressure (dBP) (RR 1.30 per +10 mmHg, 95% CI 1.02-1.66, p = .04). Mean baseline dBP, obtained at the time of randomization in the trial, was 78 mmHg (SD 13 mmHg). In a multivariable model, only dBP remained a significant predictor. The risk was not related to the type of surgical reconstruction, anaesthetic technique, or perioperative medication regimen. Patients undergoing CEA stayed a median of 4 days before discharge, and 21.2% of events occurred on or after the day of discharge. Increasing diastolic blood pressure was the only independent risk factor for stroke, MI, or death following CEA. Cautious attention to blood pressure control following symptoms attributable to carotid stenosis could reduce the risks associated with subsequent CEA. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Apixaban to prevent stroke in patients with atrial fibrillation: a review

PubMed Central

Peterson, Benjamin E.; Al-Khatib, Sana M.; Granger, Christopher B.

2016-01-01

Atrial fibrillation is a common, costly and morbid cardiovascular arrhythmia. Stroke prevention remains the mainstay of treatment for atrial fibrillation, and the recent advent of novel oral anticoagulants with direct factor IIa or factor Xa inhibition has significantly revolutionized this aspect of treatment for atrial fibrillation patients. This review focuses on the tolerability and efficacy of apixaban and tackles the generalizability of the findings with apixaban to broader patient populations than those primarily enrolled in the clinical trials, drawing from the AVERROES and ARISTOTLE trials and their subsequent secondary analyses. Taken together, findings from these trials show that apixaban is superior to warfarin in preventing stroke with a lower risk of major bleeding in the general population of patients with atrial fibrillation as well as in several key high-risk patient subgroups. PMID:27342651

Symptomatic and asymptomatic carotid artery plaque

PubMed Central

Mughal, Majid M; Khan, Mohsin K; DeMarco, J Kevin; Majid, Arshad; Shamoun, Fadi; Abela, George S

2011-01-01

Carotid atherosclerotic plaques represent both stable and unstable atheromatous lesions. Atherosclerotic plaques that are prone to rupture owing to their intrinsic composition such as a large lipid core, thin fibrous cap and intraplaque hemorrhage are associated with subsequent thromboembolic ischemic events. At least 15–20% of all ischemic strokes are attributable to carotid artery atherosclerosis. Characterization of plaques may enhance the understanding of natural history and ultimately the treatment of atherosclerotic disease. MRI of carotid plaque and embolic signals during transcranial Doppler have identified features beyond luminal stenosis that are predictive of future transient ischemic attacks and stroke. The value of specific therapies to prevent stroke in symptomatic and asymptomatic patients with severe carotid artery stenosis are the subject of current research and analysis of recently published clinical trials that are discussed in this article. PMID:21985544

Gorlin-Goltz syndrome and stroke: a case report.

PubMed

Budinčević, Hrvoje; Starčević, Katarina; Bielen, Ivan; Demarin, Vida

2014-01-01

We report on the case of a 32-years old male patient who was previously diagnosed with Gorlin-Goltz syndrome. The patient presented with sudden-onset right-sided hemiparesis, supranuclear facioparesis, and motor aphasia. He was treated with thrombolytic therapy, which successfully alleviated the symptoms. Subsequent radiologic work-up revealed anomalies in the vertebral arteries, a bifid rib, an ischemic lesion in the supply area of the left middle cerebral artery, and falx calcifications. Laboratory tests showed a 4G/4G polymorphism of the plasminogen activator inhibitor 1 (PAI-1) gene whose correlation with stroke is discussed in the article.

Etiological classifications of transient ischemic attacks: subtype classification by TOAST, CCS and ASCO--a pilot study.

PubMed

Amort, Margareth; Fluri, Felix; Weisskopf, Florian; Gensicke, Henrik; Bonati, Leo H; Lyrer, Philippe A; Engelter, Stefan T

2012-01-01

In patients with transient ischemic attacks (TIA), etiological classification systems are not well studied. The Trial of ORG 10172 in Acute Stroke Treatment (TOAST), the Causative Classification System (CCS), and the Atherosclerosis Small Vessel Disease Cardiac Source Other Cause (ASCO) classification may be useful to determine the underlying etiology. We aimed at testing the feasibility of each of the 3 systems. Furthermore, we studied and compared their prognostic usefulness. In a single-center TIA registry prospectively ascertained over 2 years, we applied 3 etiological classification systems. We compared the distribution of underlying etiologies, the rates of patients with determined versus undetermined etiology, and studied whether etiological subtyping distinguished TIA patients with versus without subsequent stroke or TIA within 3 months. The 3 systems were applicable in all 248 patients. A determined etiology with the highest level of causality was assigned similarly often with TOAST (35.9%), CCS (34.3%), and ASCO (38.7%). However, the frequency of undetermined causes differed significantly between the classification systems and was lowest for ASCO (TOAST: 46.4%; CCS: 37.5%; ASCO: 18.5%; p < 0.001). In TOAST, CCS, and ASCO, cardioembolism (19.4/14.5/18.5%) was the most common etiology, followed by atherosclerosis (11.7/12.9/14.5%). At 3 months, 33 patients (13.3%, 95% confidence interval 9.3-18.2%) had recurrent cerebral ischemic events. These were strokes in 13 patients (5.2%; 95% confidence interval 2.8-8.8%) and TIAs in 20 patients (8.1%, 95% confidence interval 5.0-12.2%). Patients with a determined etiology (high level of causality) had higher rates of subsequent strokes than those without a determined etiology [TOAST: 6.7% (95% confidence interval 2.5-14.1%) vs. 4.4% (95% confidence interval 1.8-8.9%); CSS: 9.3% (95% confidence interval 4.1-17.5%) vs. 3.1% (95% confidence interval 1.0-7.1%); ASCO: 9.4% (95% confidence interval 4.4-17.1%) vs. 2.6% (95% confidence interval 0.7-6.6%)]. However, this difference was only significant in the ASCO classification (p = 0.036). Using ASCO, there was neither an increase in risk of subsequent stroke among patients with incomplete diagnostic workup (at least one subtype scored 9) compared with patients with adequate workup (no subtype scored 9), nor among patients with multiple causes compared with patients with a single cause. In TIA patients, all etiological classification systems provided a similar distribution of underlying etiologies. The increase in stroke risk in TIA patients with determined versus undetermined etiology was most evident using the ASCO classification. Copyright © 2012 S. Karger AG, Basel.

Screening methods for post-stroke visual impairment: a systematic review.

PubMed

Hanna, Kerry Louise; Hepworth, Lauren Rachel; Rowe, Fiona

2017-12-01

To provide a systematic overview of the various tools available to screen for post-stroke visual impairment. A review of the literature was conducted including randomised controlled trials, controlled trials, cohort studies, observational studies, systematic reviews and retrospective medical note reviews. All languages were included and translation was obtained. Participants included adults ≥18 years old diagnosed with a visual impairment as a direct cause of a stroke. We searched a broad range of scholarly online resources and hand-searched articles registers of published, unpublished and on-going trials. Search terms included a variety of MESH terms and alternatives in relation to stroke and visual conditions. Study selection was performed by two authors independently. The quality of the evidence and risk of bias were assessed using the STROBE, GRACE and PRISMA statements. A total of 25 articles (n = 2924) were included in this review. Articles appraised reported on tools screening solely for visual impairments or for general post-stroke disabilities inclusive of vision. The majority of identified tools screen for visual perception including visual neglect (VN), with few screening for visual acuity (VA), visual field (VF) loss or ocular motility (OM) defects. Six articles reported on nine screening tools which combined visual screening assessment alongside screening for general stroke disabilities. Of these, three included screening for VA; three screened for VF loss; three screened for OM defects and all screened for VN. Two tools screened for all visual impairments. A further 19 articles were found which reported on individual vision screening tests in stroke populations; two for VF loss; 11 for VN and six for other visual perceptual defects. Most tools cannot accurately account for those with aphasia or communicative deficits, which are common problems following a stroke. There is currently no standardised visual screening tool which can accurately assess all potential post-stroke visual impairments. The current tools screen for only a number of potential stroke-related impairments, which means many visual defects may be missed. The sensitivity of those which screen for all impairments is significantly lowered when patients are unable to report their visual symptoms. Future research is required to develop a tool capable of assessing stroke patients which encompasses all potential visual deficits and can also be easily performed by both the patients and administered by health care professionals in order to ensure all stroke survivors with visual impairment are accurately identified and managed. Implications for Rehabilitation Over 65% of stroke survivors will suffer from a visual impairment, whereas 45% of stroke units do not assess vision. Visual impairment significantly reduces the quality of life, such as being unable to return to work, driving and depression. This review outlines the available screening methods to accurately identify stroke survivors with visual impairments. Identifying visual impairment after stroke can aid general rehabilitation and thus, improve the quality of life for these patients.

The taxonomy statistic uncovers novel clinical patterns in a population of ischemic stroke patients.

PubMed

Tukiendorf, Andrzej; Kaźmierski, Radosław; Michalak, Sławomir

2013-01-01

In this paper, we describe a simple taxonomic approach for clinical data mining elaborated by Marczewski and Steinhaus (M-S), whose performance equals the advanced statistical methodology known as the expectation-maximization (E-M) algorithm. We tested these two methods on a cohort of ischemic stroke patients. The comparison of both methods revealed strong agreement. Direct agreement between M-S and E-M classifications reached 83%, while Cohen's coefficient of agreement was κ = 0.766(P < 0.0001). The statistical analysis conducted and the outcomes obtained in this paper revealed novel clinical patterns in ischemic stroke patients. The aim of the study was to evaluate the clinical usefulness of Marczewski-Steinhaus' taxonomic approach as a tool for the detection of novel patterns of data in ischemic stroke patients and the prediction of disease outcome. In terms of the identification of fairly frequent types of stroke patients using their age, National Institutes of Health Stroke Scale (NIHSS), and diabetes mellitus (DM) status, when dealing with rough characteristics of patients, four particular types of patients are recognized, which cannot be identified by means of routine clinical methods. Following the obtained taxonomical outcomes, the strong correlation between the health status at moment of admission to emergency department (ED) and the subsequent recovery of patients is established. Moreover, popularization and simplification of the ideas of advanced mathematicians may provide an unconventional explorative platform for clinical problems.

Differences between poststroke drivers and nondrivers: demographic characteristics, medical status, and transportation use.

PubMed

Finestone, Hillel M; Marshall, Shawn C; Rozenberg, Dmitry; Moussa, Raffy C; Hunt, Lynn; Greene-Finestone, Linda S

2009-11-01

To determine the demographic, medical, and transportation use characteristics of stroke survivors wanting to drive who resumed or did not resume driving and compare the driving habits of those who drove with those of a nonstroke control group. One hundred and six stroke survivors who underwent a driving evaluation at a rehabilitation center in Ottawa, Canada, between 1995 and 2003, participated in a structured telephone interview 4-5 yrs after the evaluation. Information on driving history and transportation use before the driving assessment was obtained from the driving assessment client database. The nonstroke control group was derived from the literature. After stroke, 66% of subjects had resumed driving. Prestroke driving history was similar for drivers and nondrivers. Drivers were younger than nondrivers (mean age +/- SD, 62.7 +/- 12.7 yrs vs. 69.2 +/- 13.4 yrs; P = 0.02), had less medical comorbidity (mean modified Cumulative Illness Rating Scale score, 3.7 +/- 1.97 vs. 5.0 +/- 2.89; P = 0.01), and were less likely to rely on a walker (1.4% vs. 19.4%, P < 0.001). Self-imposed restrictions were reported by 35.7% of drivers. More nondrivers than drivers relied on family/friends (94.4% vs. 41.4%), public transportation (60.7% vs. 35.3%), or taxis (27.8% vs. 2.9%) (all P < 0.05). Drivers reported fewer driving difficulties (e.g., skill, weather, or traffic related;

A survey exploring self-reported indoor and outdoor footwear habits, foot problems and fall status in people with stroke and Parkinson's.

PubMed

Bowen, Catherine; Ashburn, Ann; Cole, Mark; Donovan-Hall, Margaret; Burnett, Malcolm; Robison, Judy; Mamode, Louis; Pickering, Ruth; Bader, Dan; Kunkel, Dorit

Ill-fitting shoes have been implicated as a risk factor for falls but research to date has focused on people with arthritis, diabetes and the general older population; little is known about people with neurological conditions. This survey for people with stroke and Parkinson's explored people's choice of indoor and outdoor footwear, foot problems and fall history. Following ethical approval, 1000 anonymous postal questionnaires were distributed to health professionals, leads of Parkinson's UK groups and stroke clubs in the wider Southampton area, UK. These collaborators handed out survey packs to people with a confirmed diagnosis of stroke or Parkinson's. Three hundred and sixty three completed surveys were returned (218 from people with Parkinson's and 145 from people with stroke). Most respondents wore slippers indoors and walking shoes outdoors and considered comfort and fit the most important factors when buying footwear. Foot problems were reported by 43 % (95 % confidence intervals 36 to 52 %; stroke) and 53 % (95 % confidence interval 46 to 59 %; Parkinson's) of respondents; over 50 % had never accessed foot care support. Fifty percent of all respondents reported falls. In comparison to non-fallers, a greater proportion of fallers reported foot problems (57 %), with greater proportions reporting problems impacting on balance and influencing choice of footwear ( p  < 0.01) in comparison to non-fallers in each case. Forty-seven percent of fallers with foot problems had not accessed foot care support. Many people with stroke and Parkinson's wear slippers indoors. A high percentage of these individuals reported both foot problems and falls impacting on footwear habits and choice of footwear; however many did not receive foot care support. These findings highlight that further exploration of footwear and foot problems in these populations is warranted to provide evidence based advice on safe and appropriate footwear to support rehabilitation and fall prevention.

Dominance of the Unaffected Hemisphere Motor Network and Its Role in the Behavior of Chronic Stroke Survivors

PubMed Central

Bajaj, Sahil; Housley, Stephen N.; Wu, David; Dhamala, Mukesh; James, G. A.; Butler, Andrew J.

2016-01-01

Balance of motor network activity between the two brain hemispheres after stroke is crucial for functional recovery. Several studies have extensively studied the role of the affected brain hemisphere to better understand changes in motor network activity following stroke. Very few studies have examined the role of the unaffected brain hemisphere and confirmed the test–retest reliability of connectivity measures on unaffected hemisphere. We recorded blood oxygenation level dependent functional magnetic resonance imaging (fMRI) signals from nine stroke survivors with hemiparesis of the left or right hand. Participants performed a motor execution task with affected hand, unaffected hand, and both hands simultaneously. Participants returned for a repeat fMRI scan 1 week later. Using dynamic causal modeling (DCM), we evaluated effective connectivity among three motor areas: the primary motor area (M1), the premotor cortex (PMC) and the supplementary motor area for the affected and unaffected hemispheres separately. Five participants’ manual motor ability was assessed by Fugl-Meyer Motor Assessment scores and root-mean square error of participants’ tracking ability during a robot-assisted game. We found (i) that the task performance with the affected hand resulted in strengthening of the connectivity pattern for unaffected hemisphere, (ii) an identical network of the unaffected hemisphere when participants performed the task with their unaffected hand, and (iii) the pattern of directional connectivity observed in the affected hemisphere was identical for tasks using the affected hand only or both hands. Furthermore, paired t-test comparison found no significant differences in connectivity strength for any path when compared with one-week follow-up. Brain-behavior linear correlation analysis showed that the connectivity patterns in the unaffected hemisphere more accurately reflected the behavioral conditions than the connectivity patterns in the affected hemisphere. Above findings enrich our knowledge of unaffected brain hemisphere following stroke, which further strengthens our neurobiological understanding of stroke-affected brain and can help to effectively identify and apply stroke-treatments. PMID:28082882

TOOTH (The Open study Of dental pulp stem cell Therapy in Humans): Study protocol for evaluating safety and feasibility of autologous human adult dental pulp stem cell therapy in patients with chronic disability after stroke.

PubMed

Nagpal, Anjali; Kremer, Karlea L; Hamilton-Bruce, Monica A; Kaidonis, Xenia; Milton, Austin G; Levi, Christopher; Shi, Songtao; Carey, Leeanne; Hillier, Susan; Rose, Miranda; Zacest, Andrew; Takhar, Parabjit; Koblar, Simon A

2016-07-01

Stroke represents a significant global disease burden. As of 2015, there is no chemical or biological therapy proven to actively enhance neurological recovery during the chronic phase post-stroke. Globally, cell-based therapy in stroke is at the stage of clinical translation and may improve neurological function through various mechanisms such as neural replacement, neuroprotection, angiogenesis, immuno-modulation, and neuroplasticity. Preclinical evidence in a rodent model of middle cerebral artery ischemic stroke as reported in four independent studies indicates improvement in neurobehavioral function with adult human dental pulp stem cell therapy. Human adult dental pulp stem cells present an exciting potential therapeutic option for improving post-stroke disability. TOOTH (The Open study Of dental pulp stem cell Therapy in Humans) will investigate the use of autologous stem cell therapy for stroke survivors with chronic disability, with the following objectives: (a) determine the maximum tolerable dose of autologous dental pulp stem cell therapy; (b) define that dental pulp stem cell therapy at the maximum tolerable dose is safe and feasible in chronic stroke; and (c) estimate the parameters of efficacy required to design a future Phase 2/3 clinical trial. TOOTH is a Phase 1, open-label, single-blinded clinical trial with a pragmatic design that comprises three stages: Stage 1 will involve the selection of 27 participants with middle cerebral artery ischemic stroke and the commencement of autologous dental pulp stem cell isolation, growth, and testing in sequential cohorts (n = 3). Stage 2 will involve the transplantation of dental pulp stem cell in each cohort of participants with an ascending dose and subsequent observation for a 6-month period for any dental pulp stem cell-related adverse events. Stage 3 will investigate the neurosurgical intervention of the maximum tolerable dose of autologous dental pulp stem cell followed by 9 weeks of intensive task-specific rehabilitation. Advanced magnetic resonance and positron emission tomography neuro-imaging, and clinical assessment will be employed to probe any change afforded by stem cell therapy in combination with rehabilitation. Nine participants will step-wise progress in Stage 2 to a dose of up to 10 million dental pulp stem cell, employing a cumulative 3 + 3 statistical design with low starting stem cell dose and subsequent dose escalation, assuming that an acceptable probability of dose-limiting complications is between 1 in 6 (17%) and 1 in 3 (33%) of patients. In Stage 3, another 18 participants will receive an intracranial injection with the maximum tolerable dose of dental pulp stem cell. The primary outcomes to be measured are safety and feasibility of intracranial administration of autologous human adult DPSC in patients with chronic stroke and determination of the maximum tolerable dose in human subjects. Secondary outcomes include estimation of the measures of effectiveness required to design a future Phase 2/3 clinical trial. © 2016 World Stroke Organization.

Postdeployment resilience as a predictor of mental health in operation enduring freedom/operation iraqi freedom returnees.

PubMed

Eisen, Susan V; Schultz, Mark R; Glickman, Mark E; Vogt, Dawne; Martin, James A; Osei-Bonsu, Princess E; Drainoni, Mari-Lynn; Elwy, A Rani

2014-12-01

Much of the research on the impact of trauma exposure among veterans has focused on factors that increase risk for mental health problems. Fewer studies have investigated factors that may prevent mental health problems following trauma exposure. This study examines resilience variables as factors that may prevent subsequent mental health problems. To determine whether military service members returning from Afghanistan and Iraq who exhibit higher levels of resilience, including hardiness (encompassing control, commitment, and challenge), self-efficacy, and social support after returning from deployment are less vulnerable to subsequent mental health problems, alcohol, and drug use. A national sample of 512 service members was surveyed between 3 and 12 months of return from deployment and 6-12 months later. Data were collected in 2008-2009 and analyzed in 2013. Regression analyses ascertained whether resilience 3-12 months after return predicted later mental health and substance problems, controlling for demographic characteristics, mental health, and risk factors, including predeployment stressful events, combat exposure, and others. Greater hardiness predicted several indicators of better mental health and lower levels of alcohol use 6-12 months later, but did not predict subsequent posttraumatic stress symptom severity. Postdeployment social support predicted better overall mental health and less posttraumatic stress symptom severity, alcohol, and drug use. Some aspects of resilience after deployment appear to protect returning service members from the negative effects of traumatic exposure, suggesting that interventions to promote and sustain resilience after deployment have the potential to enhance the mental health of veterans. Copyright © 2014 American Journal of Preventive Medicine. All rights reserved.

Substitutions of dairy product intake and risk of stroke: a Danish cohort study.

PubMed

Laursen, Anne Sofie Dam; Dahm, Christina Catherine; Johnsen, Søren Paaske; Tjønneland, Anne; Overvad, Kim; Jakobsen, Marianne Uhre

2018-02-01

Low fat dairy products are part of dietary guidelines to prevent stroke. However, epidemiological evidence is inconclusive with regard to the association between dairy products and stroke. We therefore investigated associations for substitutions between dairy product subgroups and risk of total stroke and stroke subtypes. We included 55,211 Danish men and women aged 50-64 years without previous stroke. Baseline diet was assessed by a food frequency questionnaire. Cases were identified through a national register and subsequently verified. The associations were analyzed using Cox proportional hazard regression. During a median follow-up of 13.4 years, we identified 2272 strokes, of which 1870 were ischemic (318 large artery atherosclerotic, 839 lacunar, 102 cardioembolic, 98 other determined types, 513 of unknown type), 389 were hemorrhages (273 intracerebral, 116 subarachnoid) and 13 of unknown etiology. Substitution of semi-skimmed fermented milk or cheese for whole-fat fermented milk was associated with a higher rate of ischemic stroke [semi-skimmed fermented milk: hazard ratio (HR) = 1.20 (95% confidence interval (CI) 0.99-1.45), cheese: HR = 1.14 (95% CI 0.98-1.31) per serving/day substituted] and substitutions of whole-fat fermented milk for low-fat milk, whole-fat milk or buttermilk were associated with a lower rate [low-fat milk: HR = 0.85 (95% CI 0.74-0.99), whole-fat milk: HR = 0.84 (95% CI 0.71-0.98) and buttermilk: HR = 0.83 (95% CI 0.70-0.99)]. We observed no associations for substitutions between dairy products and hemorrhagic stroke. Our results suggest that intake of whole-fat fermented milk as a substitution for semi-skimmed fermented milk, cheese, buttermilk or milk, regardless of fat content, is associated with a lower rate of ischemic stroke.

Burden of Intracranial Atherosclerosis Is Associated With Long-Term Vascular Outcome in Patients With Ischemic Stroke.

PubMed

Kim, Byung-Su; Chung, Pil-Wook; Park, Kwang-Yeol; Won, Hong-Hee; Bang, Oh Young; Chung, Chin-Sang; Lee, Kwang Ho; Kim, Gyeong-Moon

2017-10-01

Ischemic stroke patients often have intracranial atherosclerosis (ICAS), despite heterogeneity in the cause of stroke. We tested the hypothesis that ICAS burden can independently reflect the risk of long-term vascular outcome. This was a retrospective cohort study analyzing data from a prospective stroke registry enrolling consecutive patients with acute ischemic stroke or transient ischemic attack. A total of 1081 patients were categorized into no ICAS, single ICAS, and advanced ICAS (ICAS ≥2 different intracranial arteries) groups. Primary and secondary end points were time to occurrence of recurrent ischemic stroke and composite vascular outcome, respectively. Study end points by ICAS burden were compared using Cox proportional hazards models in overall and propensity-matched patients. ICAS was present in 405 patients (37.3%). During a median 5-year follow-up, recurrent stroke and composite vascular outcome occurred in 6.8% and 16.8% of patients, respectively. As the number of ICAS increased, the risk for study end points increased after adjustment of potential covariates (hazard ratio per 1 increase in ICAS, 1.19; 95% confidence interval, 1.01-1.42 for recurrent ischemic stroke and hazard ratio, 1.18; 95% confidence interval, 1.05-1.33 for composite vascular outcome). The hazard ratios (95% confidence interval) for recurrent stroke and composite vascular outcome in patients with advanced ICAS compared with those without ICAS were 1.56 (0.88-2.74) and 1.72 (1.17-2.53), respectively, in the overall patients. The corresponding values in the propensity-matched patients were 1.28 (0.71-2.30) and 1.95 (1.27-2.99), respectively. ICAS burden was independently associated with the risk of subsequent composite vascular outcome in patients with ischemic stroke. These findings suggest that ICAS burden can reflect the risk of long-term vascular outcome. © 2017 American Heart Association, Inc.

Clopidogrel with aspirin in acute minor stroke or transient ischemic attack.

PubMed

Wang, Yongjun; Wang, Yilong; Zhao, Xingquan; Liu, Liping; Wang, David; Wang, Chunxue; Wang, Chen; Li, Hao; Meng, Xia; Cui, Liying; Jia, Jianping; Dong, Qiang; Xu, Anding; Zeng, Jinsheng; Li, Yansheng; Wang, Zhimin; Xia, Haiqin; Johnston, S Claiborne

2013-07-04

Stroke is common during the first few weeks after a transient ischemic attack (TIA) or minor ischemic stroke. Combination therapy with clopidogrel and aspirin may provide greater protection against subsequent stroke than aspirin alone. In a randomized, double-blind, placebo-controlled trial conducted at 114 centers in China, we randomly assigned 5170 patients within 24 hours after the onset of minor ischemic stroke or high-risk TIA to combination therapy with clopidogrel and aspirin (clopidogrel at an initial dose of 300 mg, followed by 75 mg per day for 90 days, plus aspirin at a dose of 75 mg per day for the first 21 days) or to placebo plus aspirin (75 mg per day for 90 days). All participants received open-label aspirin at a clinician-determined dose of 75 to 300 mg on day 1. The primary outcome was stroke (ischemic or hemorrhagic) during 90 days of follow-up in an intention-to-treat analysis. Treatment differences were assessed with the use of a Cox proportional-hazards model, with study center as a random effect. Stroke occurred in 8.2% of patients in the clopidogrel-aspirin group, as compared with 11.7% of those in the aspirin group (hazard ratio, 0.68; 95% confidence interval, 0.57 to 0.81; P<0.001). Moderate or severe hemorrhage occurred in seven patients (0.3%) in the clopidogrel-aspirin group and in eight (0.3%) in the aspirin group (P=0.73); the rate of hemorrhagic stroke was 0.3% in each group. Among patients with TIA or minor stroke who can be treated within 24 hours after the onset of symptoms, the combination of clopidogrel and aspirin is superior to aspirin alone for reducing the risk of stroke in the first 90 days and does not increase the risk of hemorrhage. (Funded by the Ministry of Science and Technology of the People's Republic of China; CHANCE ClinicalTrials.gov number, NCT00979589.).

Long-term projections of temperature-related mortality risks for ischemic stroke, hemorrhagic stroke, and acute ischemic heart disease under changing climate in Beijing, China.

PubMed

Li, Tiantian; Horton, Radley M; Bader, Daniel A; Liu, Fangchao; Sun, Qinghua; Kinney, Patrick L

2018-03-01

Changing climates have been causing variations in the number of global ischemic heart disease and stroke incidences, and will continue to affect disease occurrence in the future. To project temperature-related mortality for acute ischemic heart disease, and ischemic and hemorrhagic stroke with concomitant climate warming. We estimated the exposure-response relationship between daily cause-specific mortality and daily mean temperature in Beijing. We utilized outputs from 31 downscaled climate models and two representative concentration pathways (RCPs) for the 2020s, 2050s, and 2080s. This strategy was used to estimate future net temperature along with heat- and cold-related deaths. The results for predicted temperature-related deaths were subsequently contrasted with the baseline period. In the 2080s, using the RCP8.5 and no population variation scenarios, the net total number of annual temperature-related deaths exhibited a median value of 637 (with a range across models of 434-874) for ischemic stroke; this is an increase of approximately 100% compared with the 1980s. The median number of projected annual temperature-related deaths was 660 (with a range across models of 580-745) for hemorrhagic stroke (virtually no change compared with the 1980s), and 1683 (with a range across models of 1351-2002) for acute ischemic heart disease (a slight increase of approximately 20% compared with the 1980s). In the 2080s, the monthly death projection for hemorrhagic stroke and acute ischemic heart disease showed that the largest absolute changes occurred in summer and winter while the largest absolute changes for ischemic stroke occurred in summer. We projected that the temperature-related mortality associated with ischemic stroke will increase dramatically due to climate warming. However, projected temperature-related mortality pertaining to acute ischemic heart disease and hemorrhagic stroke should remain relatively stable over time. Copyright © 2017 Elsevier Ltd. All rights reserved.

Missed strokes using computed tomography imaging in patients with vertigo: population-based cohort study.

PubMed

Grewal, Keerat; Austin, Peter C; Kapral, Moira K; Lu, Hong; Atzema, Clare L

2015-01-01

The purpose of this study was to determine the proportion of emergency department (ED) patients with a diagnosis of peripheral vertigo who received computed tomography (CT) head imaging in the ED and to examine whether strokes were missed using CT imaging. This population-based retrospective cohort study assessed patients who were discharged from an ED in Ontario, Canada, with a diagnosis of peripheral vertigo, April 2006 to March 2011. Patients who received CT imaging (exposed) were matched by propensity score methods to patients who did not (unexposed). If performed, CT imaging was presumed to be negative for stroke because brain stem/cerebellar stroke would result in hospitalization. We compared the incidence of stroke within 30, 90, and 365 days subsequent to ED discharge between groups, to determine whether the exposed group had a higher frequency of early strokes than the matched unexposed group. Among 41 794 qualifying patients, 8596 (20.6%) received ED head CT imaging, and 99.8% of these patients were able to be matched to a control. Among exposed patients, 25 (0.29%) were hospitalized for stroke within 30 days when compared with 11 (0.13%) among matched nonexposed patients. The relative risk of a 30- and 90-day stroke among exposed versus unexposed patients was 2.27 (95% confidence interval, 1.12-4.62) and 1.94 (95% confidence interval, 1.10-3.43), respectively. There was no difference between groups at 1 year. Strokes occurred at a median of 32.0 days (interquartile range, 4.0-33.0 days) in exposed patients, compared with 105 days (interquartile range, 11.5-204.5) in unexposed patients. One fifth of patients diagnosed with peripheral vertigo in Ontario received imaging that is not recommended in guidelines, and that imaging was associated with missed strokes. © 2014 American Heart Association, Inc.

29 CFR 1450.17 - Contracting for collection services.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Practices Act, 15 U.S.C. 1692; (3) The contractor must be required to account strictly for all amounts collected; (4) The contractor must agree that uncollectible accounts shall be returned with appropriate... returning an account to FMCS for subsequent referral to the Department of Justice for litigation. (b...

Direct numerical simulation of auto-ignition of a hydrogen vortex ring reacting with hot air

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

Doom, Jeff; Mahesh, Krishnan

2009-04-15

Direct numerical simulation (DNS) is used to study chemically reacting, laminar vortex rings. A novel, all-Mach number algorithm developed by Doom et al. [J. Doom, Y. Hou, K. Mahesh, J. Comput. Phys. 226 (2007) 1136-1151] is used. The chemical mechanism is a nine species, nineteen reaction mechanism for H{sub 2}/air combustion proposed by Mueller et al. [M.A. Mueller, T.J. Kim, R.A. Yetter, F.L. Dryer, Int. J. Chem. Kinet. 31 (1999) 113-125]. Diluted H{sub 2} at ambient temperature (300 K) is injected into hot air. The simulations study the effect of fuel/air ratios, oxidizer temperature, Lewis number and stroke ratio (ratiomore » of piston stroke length to diameter). Results show that auto-ignition occurs in fuel lean, high temperature regions with low scalar dissipation at a 'most reactive' mixture fraction, {zeta}{sub MR} (Mastorakos et al. [E. Mastorakos, T.A. Baritaud, T.J. Poinsot, Combust. Flame 109 (1997) 198-223]). Subsequent evolution of the flame is not predicted by {zeta}{sub MR}; a most reactive temperature T{sub MR} is defined and shown to predict both the initial auto-ignition as well as subsequent evolution. For stroke ratios less than the formation number, ignition in general occurs behind the vortex ring and propagates into the core. At higher oxidizer temperatures, ignition is almost instantaneous and occurs along the entire interface between fuel and oxidizer. For stroke ratios greater than the formation number, ignition initially occurs behind the leading vortex ring, then occurs along the length of the trailing column and propagates toward the ring. Lewis number is seen to affect both the initial ignition as well as subsequent flame evolution significantly. Non-uniform Lewis number simulations provide faster ignition and burnout time but a lower maximum temperature. The fuel rich reacting vortex ring provides the highest maximum temperature and the higher oxidizer temperature provides the fastest ignition time. The fuel lean reacting vortex ring has little effect on the flow and behaves similar to a non-reacting vortex ring. (author)« less

Ischemic Heart Disease and Stroke in Relation to Blood DNA Methylation

PubMed Central

Baccarelli, Andrea; Wright, Robert; Bollati, Valentina; Litonjua, Augusto; Zanobetti, Antonella; Tarantini, Letizia; Sparrow, David; Vokonas, Pantel; Schwartz, Joel

2013-01-01

Background Epigenetic features such as DNA hypomethylation have been associated with conditions related to cardiovascular risk. We evaluated whether lower blood DNA methylation in heavily methylated repetitive sequences predicts the risk of ischemic heart disease and stroke. Methods We quantified blood DNA methylation of LINE-1 repetitive elements through PCR-pyrosequencing in 712 elderly individuals from the Boston-area Normative Aging Study. We estimated risk-factor adjusted relative risks (RRs) for ischemic heart disease and stroke at baseline (242 prevalent cases); as well as in incidence (44 new cases; median follow-up, 63 months); and subsequent mortality from ischemic heart disease (86 deaths; median follow-up, 75 months). Results Blood LINE-1 hypomethylation was associated with baseline ischemic heart disease (RR=2.1 [95% confidence interval = 1.2 to 4.0] for lowest vs. highest methylation quartile) and for stroke (2.5 [0.9 to 7.5]). Among participants free of baseline disease, individuals with methylation below the median also had higher risk of developing ischemic heart disease (4.0 [1.8 to 8.9]) or stroke (5.7 [0.8 to 39.5]). In the entire cohort, persons with methylation below the median had higher mortality from ischemic heart disease (3.3 [1.3 to 8.4]) and stroke (2.8 [0.6 to 14.3]). Total mortality was also increased (2.0 [1.2 to 3.3]). These results were confirmed in additional regression models using LINE-1 methylation as a continuous variable. Conclusions Subjects with prevalent IHD and stroke exhibited lower LINE-1 methylation. In longitudinal analyses, persons with lower LINE-1 methylation were at higher risk for incident ischemic heart disease and stroke, and for total mortality. PMID:20805753

A case-control study of the effectiveness of tissue plasminogen activator on 6 month patients--reported outcomes and health care utilization.

PubMed

Lang, Catherine E; Bland, Marghuretta D; Cheng, Nuo; Corbetta, Maurizio; Lee, Jin-Moo

2014-01-01

We examined the benefit of tissue plasminogen activator (tPA), delivered as part of usual stroke management, on patient-reported outcomes and health care utilization. Using a case control design, patients who received tPA as part of usual stroke management were compared with patients who would have received tPA had they arrived to the hospital within the therapeutic time window. Data were collected from surveys 6 months after stroke using standardized patient-reported outcome measures and questions about health care utilization. Demographic and medical data were acquired from hospital records. Patients were matched on stroke severity, age, race, and gender. Matching was done with 1:2 ratio of tPA to controls. Results were compared between groups with 1-tailed tests because of a directionally specific hypothesis in favor of the tPA group. The tPA (n = 78) and control (n = 156) groups were matched across variables, except for stroke severity, which was better in the control group; subsequent analyses controlled for this mismatch. The tPA group reported better physical function, communication, cognitive ability, depressive symptomatology, and quality of life/participation compared with the control group. Fewer people in the tPA group reported skilled nursing facility stays, emergency department visits, and rehospitalizations after their stroke compared with controls. Reports of other postacute services were not different between groups. Although it is known that tPA reduces disability, this is the first study to demonstrate the effectiveness of tPA in improving meaningful, patient-reported outcomes. Thus, use of tPA provides a large benefit to the daily lives of people with ischemic stroke. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

2018 Guidelines for the Early Management of Patients With Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association.

PubMed

Powers, William J; Rabinstein, Alejandro A; Ackerson, Teri; Adeoye, Opeolu M; Bambakidis, Nicholas C; Becker, Kyra; Biller, José; Brown, Michael; Demaerschalk, Bart M; Hoh, Brian; Jauch, Edward C; Kidwell, Chelsea S; Leslie-Mazwi, Thabele M; Ovbiagele, Bruce; Scott, Phillip A; Sheth, Kevin N; Southerland, Andrew M; Summers, Deborah V; Tirschwell, David L

2018-03-01

The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations for clinicians caring for adult patients with acute arterial ischemic stroke in a single document. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators. These guidelines supersede the 2013 guidelines and subsequent updates. Members of the writing group were appointed by the American Heart Association Stroke Council's Scientific Statements Oversight Committee, representing various areas of medical expertise. Strict adherence to the American Heart Association conflict of interest policy was maintained. Members were not allowed to participate in discussions or to vote on topics relevant to their relations with industry. The members of the writing group unanimously approved all recommendations except when relations with industry precluded members voting. Prerelease review of the draft guideline was performed by 4 expert peer reviewers and by the members of the Stroke Council's Scientific Statements Oversight Committee and Stroke Council Leadership Committee. These guidelines use the American College of Cardiology/American Heart Association 2015 Class of Recommendations and Levels of Evidence and the new American Heart Association guidelines format. These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks. The guidelines support the overarching concept of stroke systems of care in both the prehospital and hospital settings. These guidelines are based on the best evidence currently available. In many instances, however, only limited data exist demonstrating the urgent need for continued research on treatment of acute ischemic stroke. © 2018 American Heart Association, Inc.

Diagnostic performance of bone metabolic indexes for the detection of stroke.

PubMed

Tan, Li Ming; Wang, Lu; Chen, Juan-Juan; Li, Hua; Luo, Wen-Bo

2017-01-01

To explore the diagnostic performance of 25-hydroxyvitamin D (25(OH)D), parathyroid hormone (PTH), bone alkaline phosphatase (BALP), and osteocalcin (OC) in predicting stroke.  Methods: This retrospective survey was conducted in The Second Affiliated Hospital to Nanchang University, Nanchang, Jiangxi Province, China. involved 121 cerebral infarction patients and 103 cerebral hemorrhage patients as the experimental groups, 100 volunteers as the healthy control group and 80 brain trauma patients as the disease control group. The 25(OH)D, PTH, BALP, and OC levels of all participants were measured by electrochemiluminescence immunoassay.  Results: The serum concentration of 25(OH)D in stroke patients was appreciably lower than that of the control groups (p less than 0.05), and subsequently, the deficiency level of 25(OH)D in the stroke population was considerably higher than that of the control groups (p less than 0.05). The serum concentrations of PTH and OC in stroke patients exceeded those found in the control groups (p less than 0.05), and the abnormal level in the stroke patients was also higher than that of the control. Compared with the control group, BALP concentrations in cerebral infarction patients were increased significantly. Additionally, abnormal levels of BALP in stroke patients were found to be higher than those in the control groups. However, concentrations and abnormal levels of BALP in cerebral hemorrhage patients were not found to be significantly different than those found in cerebral infarction and the control groups, There were no substantial differences between the 2 control groups. Conclusion: Lack of 25(OH)D and excessive PTH, BALP, and OC could indicate a high risk of stroke.

Preadmission use of nonaspirin nonsteroidal anti-inflammatory drugs and 30-day stroke mortality.

PubMed

Schmidt, Morten; Hováth-Puhó, Erzsébet; Christiansen, Christian Fynbo; Petersen, Karin L; Bøtker, Hans Erik; Sørensen, Henrik Toft

2014-11-25

To examine whether preadmission use of nonaspirin nonsteroidal anti-inflammatory drugs (NSAIDs) influenced 30-day stroke mortality. We conducted a nationwide population-based cohort study. Using medical databases, we identified all first-time stroke hospitalizations in Denmark between 2004 and 2012 (n = 100,043) and subsequent mortality. We categorized NSAID use as current (prescription redemption within 60 days before hospital admission), former, and nonuse. Current use was further classified as new or long-term use. Cox regression was used to compute hazard ratios (HRs) of death within 30 days, controlling for potential confounding through multivariable adjustment and propensity score matching. The adjusted HR of death for ischemic stroke was 1.19 (95% confidence interval [CI]: 1.02-1.38) for current users of selective cyclooxygenase (COX)-2 inhibitors compared with nonusers, driven by the effect among new users (1.42, 95% CI: 1.14-1.77). Comparing the different COX-2 inhibitors, the HR was driven by new use of older traditional COX-2 inhibitors (1.42, 95% CI: 1.14-1.78) among which it was 1.53 (95% CI: 1.02-2.28) for etodolac and 1.28 (95% CI: 0.98-1.68) for diclofenac. The propensity score-matched analysis supported the association between older COX-2 inhibitors and ischemic stroke mortality. There was no association for former users. Mortality from intracerebral hemorrhage was not associated with use of nonselective NSAIDs or COX-2 inhibitors. Preadmission use of COX-2 inhibitors was associated with increased 30-day mortality after ischemic stroke, but not hemorrhagic stroke. Use of nonselective NSAIDs at time of admission was not associated with mortality from ischemic stroke or intracerebral hemorrhage. © 2014 American Academy of Neurology.

Longitudinal Changes of Resting-State Functional Connectivity during Motor Recovery after Stroke

PubMed Central

Park, Chang-hyun; Chang, Won Hyuk; Ohn, Suk Hoon; Kim, Sung Tae; Bang, Oh Young; Pascual-Leone, Alvaro; Kim, Yun-Hee

2013-01-01

Background and Purpose Functional magnetic resonance imaging (fMRI) studies could provide crucial information on the neural mechanisms of motor recovery in stroke patients. Resting-state fMRI is applicable to stroke patients who are not capable of proper performance of the motor task. In this study, we explored neural correlates of motor recovery in stroke patients by investigating longitudinal changes in resting-state functional connectivity of the ipsilesional primary motor cortex (M1). Methods A longitudinal observational study using repeated fMRI experiments was conducted in 12 patients with stroke. Resting-state fMRI data were acquired four times over a period of 6 months. Patients participated in the first session of fMRI shortly after onset, and thereafter in subsequent sessions at 1, 3, and 6 months after onset. Resting-state functional connectivity of the ipsilesional M1 was assessed and compared with that of healthy subjects. Results Compared with healthy subjects, patients demonstrated higher functional connectivity with the ipsilesional frontal and parietal cortices, bilateral thalamus, and cerebellum. Instead, functional connectivity with the contralesional M1 and occipital cortex were decreased in stroke patients. Functional connectivity between the ipsilesional and contralesional M1 showed the most asymmetry at 1 month after onset to the ipsilesional side. Functional connectivity of the ipsilesional M1 with the contralesional thalamus, supplementary motor area, and middle frontal gyrus at onset was positively correlated with motor recovery at 6 months after stroke. Conclusions Resting-state fMRI elicited distinctive but comparable results with previous task-based fMRI, presenting complementary and practical values for use in the study of stroke patients. PMID:21441147

Positive cloud-to-ground lightning flashes in severe storms

NASA Technical Reports Server (NTRS)

Rust, W. D.; Macgorman, D. R.; Arnold, R. T.

1981-01-01

The occurrence of cloud-to-ground flashes that effectively lower positive charge to earth (+CG flash) over flat terrain has been documented in the mature stage of severe thunderstorms. Of the 31 documented +CG flashes, most had only one return stroke. Zero-to-peak rise times for the strokes averaged 7 microsec. The +CG flashes averaged 520 ms in duration, with 25 percent lasting more than 800 ms. Many of these had field changes suggestive of continuing current. Positive flashes have been observed to emanate from several regions of severe storms: high on the back of the main storm tower, through the wall cloud, and from the downshear anvil. Visually most of these positive flashes have emanated from high in the storm, and acoustic mapping of two shows thunder sources to a height of about 15 km.

Slower EEG alpha generation, synchronization and "flow"-possible biomarkers of cognitive impairment and neuropathology of minor stroke.

PubMed

Petrovic, Jelena; Milosevic, Vuk; Zivkovic, Miroslava; Stojanov, Dragan; Milojkovic, Olga; Kalauzi, Aleksandar; Saponjic, Jasna

2017-01-01

We investigated EEG rhythms, particularly alpha activity, and their relationship to post-stroke neuropathology and cognitive functions in the subacute and chronic stages of minor strokes. We included 10 patients with right middle cerebral artery (MCA) ischemic strokes and 11 healthy controls. All the assessments of stroke patients were done both in the subacute and chronic stages. Neurological impairment was measured using the National Institute of Health Stroke Scale (NIHSS), whereas cognitive functions were assessed using the Montreal Cognitive Assessment (MoCA) and MoCA memory index (MoCA-MIS). The EEG was recorded using a 19 channel EEG system with standard EEG electrode placement. In particular, we analyzed the EEGs derived from the four lateral frontal (F3, F7, F4, F8), and corresponding lateral posterior (P3, P4, T5, T6) electrodes. Quantitative EEG analysis included: the group FFT spectra, the weighted average of alpha frequency (αAVG), the group probability density distributions of all conventional EEG frequency band relative amplitudes (EEG microstructure), the inter- and intra-hemispheric coherences, and the topographic distribution of alpha carrier frequency phase potentials (PPs). Statistical analysis was done using a Kruskal-Wallis ANOVA with a post-hoc Mann-Whitney U two-tailed test, and Spearman's correlation. We demonstrated transient cognitive impairment alongside a slower alpha frequency ( α AVG) in the subacute right MCA stroke patients vs. the controls. This slower alpha frequency showed no amplitude change, but was highly synchronized intra-hemispherically, overlying the ipsi-lesional hemisphere, and inter-hemispherically, overlying the frontal cortex. In addition, the disturbances in EEG alpha activity in subacute stroke patients were expressed as a decrease in alpha PPs over the frontal cortex and an altered "alpha flow", indicating the sustained augmentation of inter-hemispheric interactions. Although the stroke induced slower alpha was a transient phenomenon, the increased alpha intra-hemispheric synchronization, overlying the ipsi-lesional hemisphere, the increased alpha F3-F4 inter-hemispheric synchronization, the delayed alpha waves, and the newly established inter-hemispheric "alpha flow" within the frontal cortex, remained as a permanent consequence of the minor stroke. This newly established frontal inter-hemispheric "alpha flow" represented a permanent consequence of the "hidden" stroke neuropathology, despite the fact that cognitive impairment has been returned to the control values. All the detected permanent changes at the EEG level with no cognitive impairment after a minor stroke could be a way for the brain to compensate for the lesion and restore the lost function. Our study indicates slower EEG alpha generation, synchronization and "flow" as potential biomarkers of cognitive impairment onset and/or compensatory post-stroke re-organizational processes.

Stroke as the First Clinical Manifestation of Takayasu's Arteritis.

PubMed

Pereira, Vanessa Caldeira; de Freitas, Carlos Clayton Macedo; Luvizutto, Gustavo José; Sobreira, Marcone Lima; Peixoto, Daniel Escobar Bueno; Magalhães, Inaldo do Nascimento; Bazan, Rodrigo; Braga, Gabriel Pereira

2014-09-01

Takayasu's arteritis is a chronic inflammatory disease, and neurological symptoms occur in 50% of cases, most commonly including headache, dizziness, visual disturbances, convulsive crisis, transient ischemic attack, stroke and posterior reversible encephalopathy syndrome. The aim of this study was to report the case of a young Brazilian female with a focal neurological deficit. She presented with asymmetry of brachial and radial pulses, aphasia, dysarthria and right hemiplegia. Stroke was investigated extensively in this young patient. Only nonspecific inflammatory markers such as velocity of hemosedimentation and C-reactive protein were elevated. During hospitalization, clinical treatment was performed with pulse therapy showing improvement in neurological recuperation on subsequent days. In the chronic phase, the patient was submitted to medicated angioplasty of the brachiocephalic trunk with paclitaxel, with significant improvement of the stenosis. At the 6-month follow-up, the neurological exam presented mild dysarthria, faciobrachial predominant disproportionate hemiparesis, an NIHSS score of 4 and a modified Rankin Scale score of 3 (moderate incapacity). In conclusion, Takayasu's arteritis must be recognized as a potential cause of ischemic stroke in young females.

Lovis Corinth: integrating hemineglect and spatial distortions.

PubMed

Bäzner, H; Hennerici, M G

2007-01-01

Lovis Corinth suffered a right-hemispheric stroke at the age of 53 years, but died only 14 years later. The huge number of artworks that he produced after this life-threatening disease allows a detailed analysis of his poststroke artwork in comparison to his prestroke artwork. When performing this analysis as a neurologist, an enormous diversity of subtle stroke sequelae can be discovered, which can mostly be explained by a left-sided hemineglect. These findings clearly go far beyond pure psychological processes. Moreover, Corinth is a good and motivating example for patients suffering disability after a stroke, because he was able to produce great artwork after his stroke. Lovis Corinth was struggling against motor disability that admittedly was not severely affecting his artistic production but he also had to fight against severe neuropsychological deficits that did have clear consequences for his artistic production. Corinth's credo was 'true art means to use unreality'. Taken together with the often cited phrase of 'drawing means to [details]', there will be a clear-cut interpretation for the neurologist that can be derived from the understanding of a right-hemisphere lesion and subsequent left-sided neglect.