Localization of the transverse processes in ultrasound for spinal curvature measurement

NASA Astrophysics Data System (ADS)

Kamali, Shahrokh; Ungi, Tamas; Lasso, Andras; Yan, Christina; Lougheed, Matthew; Fichtinger, Gabor

2017-03-01

PURPOSE: In scoliosis monitoring, tracked ultrasound has been explored as a safer imaging alternative to traditional radiography. The use of ultrasound in spinal curvature measurement requires identification of vertebral landmarks such as transverse processes, but as bones have reduced visibility in ultrasound imaging, skeletal landmarks are typically segmented manually, which is an exceedingly laborious and long process. We propose an automatic algorithm to segment and localize the surface of bony areas in the transverse process for scoliosis in ultrasound. METHODS: The algorithm uses cascade of filters to remove low intensity pixels, smooth the image and detect bony edges. By applying first differentiation, candidate bony areas are classified. The average intensity under each area has a correlation with the possibility of a shadow, and areas with strong shadow are kept for bone segmentation. The segmented images are used to reconstruct a 3-D volume to represent the whole spinal structure around the transverse processes. RESULTS: A comparison between the manual ground truth segmentation and the automatic algorithm in 50 images showed 0.17 mm average difference. The time to process all 1,938 images was about 37 Sec. (0.0191 Sec. / Image), including reading the original sequence file. CONCLUSION: Initial experiments showed the algorithm to be sufficiently accurate and fast for segmentation transverse processes in ultrasound for spinal curvature measurement. An extensive evaluation of the method is currently underway on images from a larger patient cohort and using multiple observers in producing ground truth segmentation.

Predictors of serum chromium levels after stainless steel posterior spinal instrumentation for adolescent idiopathic scoliosis.

PubMed

Rackham, Matthew D; Cundy, Thomas P; Antoniou, Georgia; Freeman, Brian J C; Sutherland, Leanne M; Cundy, Peter J

2010-04-20

Prospective cohort study. To determine the predictors of serum chromium levels after stainless steel posterior spinal instrumentation for adolescent idiopathic scoliosis. Abnormally elevated serum chromium levels have been detected in patients with adolescent idiopathic scoliosis after stainless steel instrumentation. To date, the relationship among serum chromium levels, time of implantation, and implant characteristics (including surface area, rod length, numbers of hooks, screws, and cross connectors) has not been studied. Thirty patients with adolescent idiopathic scoliosis undergoing posterior instrumented spinal arthrodesis using stainless steel implants between 1998 and 2002 were prospectively studied. Serum chromium levels were measured between October 2006 and June 2007. Postoperative radiographs were used to measure rod lengths, number of hooks, screws, cross-connectors, and cables. The surface area of each component and the total surface area for each patient were calculated. Possible associations between serum chromium levels, time of implantation, and implant characteristics were investigated. Implant exposure, whether expressed in the form of total metal implant surface area, rod length, or number of metal interfaces, was found to be positively associated with serum chromium levels. Specifically, chromium levels increased by a multiplicative factor of 1.0060 for every additional square centimeter of total metal implant surface area (P = 0.02). In addition, the chromium level was found to decrease by a multiplicative factor of 0.7766 for every additional year since surgery (P = 0.02). After adjusting for the number of years since surgery, metal implant exposure is positively associated with elevated serum chromium levels in adolescent idiopathic scoliosis patients with stainless steel posterior spinal implants. This is the first study to identify statistically significant positive associations between specific spinal implant characteristics (other than

A Review of Pinealectomy-Induced Melatonin-Deficient Animal Models for the Study of Etiopathogenesis of Adolescent Idiopathic Scoliosis

PubMed Central

Wai, Man Gene Chi; Jun, Wang William Wei; Yee, Yim Annie Po; Ho, Wong Jack; Bun, Ng Tzi; Ping, Lam Tsz; Man, Lee Simon Kwong; Wah, Ng Bobby Kin; Chiu, Wang Chi; Yong, Qiu; Yiu, Cheng Jack Chun

2014-01-01

Adolescent idiopathic scoliosis (AIS) is a common orthopedic disorder of unknown etiology and pathogenesis. Melatonin and melatonin pathway dysfunction has been widely suspected to play an important role in the pathogenesis. Many different types of animal models have been developed to induce experimental scoliosis mimicking the pathoanatomical features of idiopathic scoliosis in human. The scoliosis deformity was believed to be induced by pinealectomy and mediated through the resulting melatonin-deficiency. However, the lack of upright mechanical spinal loading and inherent rotational instability of the curvature render the similarity of these models to the human counterparts questionable. Different concerns have been raised challenging the scientific validity and limitations of each model. The objectives of this review follow the logical need to re-examine and compare the relevance and appropriateness of each of the animal models that have been used for studying the etiopathogenesis of adolescent idiopathic scoliosis in human in the past 15 to 20 years. PMID:25238413

Impact of Glycemic Control on Morbidity and Mortality in Adult Idiopathic Scoliosis Patients Undergoing Spinal Fusion.

PubMed

Shin, John I; Phan, Kevin; Kothari, Parth; Kim, Jun S; Guzman, Javier Z; Cho, Samuel K

2017-08-01

This is a retrospective analysis of administrative database. To elucidate the effect of glycemic control on surgical outcomes of middle-aged and elderly idiopathic scoliosis patients undergoing spinal fusion surgery. Diabetes mellitus (DM) is a condition thought to adversely affect outcomes of spine surgery. However, no study has stratified glycemic control levels and their impact on outcome for idiopathic scoliosis patients receiving a spinal fusion surgery. Previous studies may have reported higher than true rates of complications for controlled diabetic patients, who are the majority of diabetic patients. The Nationwide Inpatient Sample was queried from years 2002 to 2011. We extracted idiopathic scoliosis patients older than 45 years of age that received spinal fusion and analyzed complications and outcomes variables among 3 cohorts: nondiabetic patients, controlled diabetics, and uncontrolled diabetics. Multivariate analyses were used to assess whether glycemic control was a risk factor for adverse postoperative outcomes. Controlled diabetics had significantly increased rates of acute renal failure (ARF), while uncontrolled diabetics had significantly increased rates of acute postoperative hemorrhage. In multivariate analyses controlling for patient factors and comorbidities, controlled DM was found to be an independent predictor of ARF [odds ratio (OR), 1.863; 95% confidence interval (CI), 1.346-2.579; P=0.0002), and uncontrolled DM was found to be a significant risk factor for acute postoperative hemorrhage (OR, 2.182; 95% CI, 1.192-3.997; P=0.0115), ARF (OR, 4.839; 95% CI, 1.748-13.392; P=0.0024), deep vein thrombosis (OR, 5.825; 95% CI, 1.329-25.522, P=0.0194) and in-patient mortality (OR, 8.889; 95% CI, 1.001-78.945; P=0.0499). Controlled DM was found to be a risk factor for ARF in adult idiopathic scoliosis patients undergoing spinal fusion surgery, while uncontrolled DM was shown to be a risk factor for postoperative hemorrhage, ARF, deep vein

The effect of myofascial release (MFR) on an adult with idiopathic scoliosis.

PubMed

LeBauer, Aaron; Brtalik, Robert; Stowe, Katherine

2008-10-01

The lack of evidence of conservative treatment has led to an interest in exploring myofascial release (MFR) as an effective means of controlling spinal curvature progression in adolescents with idiopathic scoliosis. The purpose of this case study is to measure the effects of MFR as a manual therapy technique in the treatment of idiopathic scoliosis. One 18-year-old female subject underwent 6 weeks of MFR treatment consisting of two sessions each week for 60min. Pain, pulmonary function, and quality of life were measured. Six goniometric measurements were taken encompassing trunk flexion, extension, and rotation. The subject improved with pain levels, trunk rotation, posture, quality of life, and pulmonary function. The results suggest further investigation is needed using MFR, as an effective manual therapy treatment for idiopathic scoliosis.

The effect of spinal curvature on the photogrammetric assessment on static balance in elderly women.

PubMed

Drzał-Grabiec, Justyna; Rachwał, Maciej; Podgórska-Bednarz, Justyna; Rykała, Justyna; Snela, Sławomir; Truszczyńska, Aleksandra; Trzaskoma, Zbigniew

2014-05-29

Involutional changes to the body in elderly patients affect the shape of the spine and the activity of postural muscles. The purpose of this study was to assess the influence of age-related changes in spinal curvature on postural balance in elderly women. The study population consisted of 90 women, with a mean age of 70 ± 8.01 years. Static balance assessments were conducted on a tensometric platform, and posturographic assessments of body posture were performed using a photogrammetric method based on the Projection Moiré method. The results obtained were analysed using the Spearman's rank correlation coefficient test. We found a statistically significant correlation between body posture and the quality of the balance system response based on the corrective function of the visual system. The shape of the spinal curvature influenced postural stability, as measured by static posturography. Improvement in the quality of the balance system response depended on corrective information from the visual system and proprioceptive information from the paraspinal muscles. The sensitivity of the balance system to the change of centre of pressure location was influenced by the direction of the change in rotation of the shoulder girdle and spine. Development of spinal curvature in the sagittal plane and maintenance of symmetry in the coronal and transverse planes are essential for correct balance control, which in turn is essential for the development of a properly proportioned locomotor system.

Comparison of portable and conventional ultrasound imaging in spinal curvature measurement

NASA Astrophysics Data System (ADS)

Yan, Christina; Tabanfar, Reza; Kempston, Michael; Borschneck, Daniel; Ungi, Tamas; Fichtinger, Gabor

2016-03-01

PURPOSE: In scoliosis monitoring, tracked ultrasound has been explored as a safer imaging alternative to traditional radiography. The use of ultrasound in spinal curvature measurement requires identification of vertebral landmarks, but bones have reduced visibility in ultrasound imaging and high quality ultrasound machines are often expensive and not portable. In this work, we investigate the image quality and measurement accuracy of a low cost and portable ultrasound machine in comparison to a standard ultrasound machine in scoliosis monitoring. METHODS: Two different kinds of ultrasound machines were tested on three human subjects, using the same position tracker and software. Spinal curves were measured in the same reference coordinate system using both ultrasound machines. Lines were defined by connecting two symmetric landmarks identified on the left and right transverse process of the same vertebrae, and spinal curvature was defined as the transverse process angle between two such lines, projected on the coronal plane. RESULTS: Three healthy volunteers were scanned by both ultrasound configurations. Three experienced observers localized transverse processes as skeletal landmarks and obtained transverse process angles in images obtained from both ultrasounds. The mean difference per transverse process angle measured was 3.00 +/-2.1°. 94% of transverse processes visualized in the Sonix Touch were also visible in the Telemed. Inter-observer error in the Telemed was 4.5° and 4.3° in the Sonix Touch. CONCLUSION: Price, convenience and accessibility suggest the Telemed to be a viable alternative in scoliosis monitoring, however further improvements in measurement protocol and image noise reduction must be completed before implementing the Telemed in the clinical setting.

[Rehabilitative treatment of idiopathic scoliosis in children and adolescents].

PubMed

Miriutova, N F; Kirichuk, S V; Lipina, E V

2009-01-01

Examination of 1326 children and adolescents revealed physiological asymmetry of neuro-orthopedic status in 57% of the subjects, functional scoliosis in 33%, and structural scoliosis in 4.5%. Only 5.5% of the examined children and adolescents did not show clinical and functional signs of spinal pathology. Treatment with mechanical vibrations (vibro-massage or "swing" therapy), pulsed extremely high frequency (EHF) waves and electrical current yielded good therapeutic effect in cases with idiopathic scoliosis. Specifically, it resulted in a diminished angle of curvature of the spine and improved muscular support of the spine.

Idiopathic normal pressure hydrocephalus: theoretical concept of a spinal etiology.

PubMed

Hamlat, Abderrahmane; Abderrahmane, Hamlat; Sid-Ahmed, Seddik; Seddik, Sid-Ahmed; Adn, Mahmoudreza; Mahmoudreza, Adn; Askar, Brahim; Brahim, Askar; Pasqualini, Edouardo; Edouardo, Pasqualini

2006-01-01

Normal pressure hydrocephalus (NPH) is an adult syndrome characterised by a combination of gait disturbance, varying degrees of cognitive decline, urinary incontinence, ventricular enlargement and normal mean intracranial pressure. Since this syndrome was first described, its pathophysiology has been a matter of great debate, although it is now considered that NPH could be divided into two groups: cases with unknown etiology (idiopathic normal pressure hydrocephalus, or INPH) and those which develop from several known causes (such as trauma, meningitis or subarachnoid haemorrhage). The pathophysiology of INPH is still unclear and a matter of debate. In this manuscript, the current pathophysiological conditions of INPH are analysed and the authors put forward the theory that the disease is a dynamic syndrome which occurs in patients who have suffered a significant loss of spinal compliance over time. Consequently, intracranial pressure increases more during systole in INPH patients because it cannot be compensated for by the escape of CSF into the spinal canal as effectively, due to the reduced volume or lack of distension of the spinal canal. This leads to an increase in ventricular size and causes cumulative brain damage over a long period of time and accounts for the slow, progressive nature of NPH. The loss of spinal compliance with age is fundamental to the proposed theory which provides a theoretical justification for studying the spinal canal in INPH and investigating the relationship between the progressive narrowing of the spinal canal and the compensating ability of the craniospinal system.

Analysis of factors that affect shoulder balance after correction surgery in scoliosis: a global analysis of all the curvature types.

PubMed

Hong, Jae-Young; Suh, Seung-Woo; Modi, Hitesh N; Yang, Jae-Hyuk; Park, Si-Young

2013-06-01

To identify factors that can affect postoperative shoulder balance in AIS. 89 adolescent idiopathic scoliosis patients with six types of curvatures who underwent surgery were included in this study. Whole spine antero-posterior and lateral radiographs were obtained pre- and postoperatively. In radiograms, shape and changes in curvatures were analyzed. In addition, four shoulder parameters and coronal balance were analyzed in an effort to identify factors significantly related to postoperative shoulder balance. In general, all the four shoulder parameters (CHD, CA, CRID, RSH) were slightly increased at final follow up (t test, P < 0.05), although there was a decrease in Lenke type II and IV curvatures. However, pre- and postoperative shoulder parameters were not significantly different between each curvature types (ANOVA, P > 0.05). Moreover, no significant differences of pre- and postoperative shoulder level between different level of proximal fusion groups (ANOVA, P > 0.05) existed. In the analysis of coronal curvature changes, no difference was observed in every individual coronal curvatures between improved shoulder balance and aggravated groups (P > 0.05). However, the middle to distal curve change ratio was significantly lower in patients with aggravated shoulder balance (P < 0.05). In addition, patients with smaller preoperative shoulder imbalance showed the higher chance of aggravation after surgery with similar postoperative changes (P < 0.05). Significant relations were found between correction rate of middle, and distal curvature, and postoperative shoulder balance. In addition, preoperative shoulder level difference can be a determinant of postoperative shoulder balance.

Return to sports after surgery to correct adolescent idiopathic scoliosis: a survey of the Spinal Deformity Study Group.

PubMed

Lehman, Ronald A; Kang, Daniel G; Lenke, Lawrence G; Sucato, Daniel J; Bevevino, Adam J

2015-05-01

There are no guidelines for when surgeons should allow patients to return to sports and athletic activities after spinal fusion for adolescent idiopathic scoliosis (AIS). Current recommendations are based on anecdotal reports and a survey performed more than a decade ago in the era of first/second-generation posterior implants. To identify current recommendations for return to sports and athletic activities after surgery for AIS. Questionnaire-based survey. Adolescent idiopathic scoliosis after corrective surgery. Type and time to return to sports. A survey was administered to members of the Spinal Deformity Study Group. The survey consisted of surgeon demographic information, six clinical case scenarios, three different construct types (hooks, pedicle screws, hybrid), and questions regarding the influence of lowest instrumented vertebra (LIV) and postoperative physical therapy. Twenty-three surgeons completed the survey, and respondents were all experienced expert deformity surgeons. Pedicle screw instrumentation allows earlier return to noncontact and contact sports, with most patients allowed to return to running by 3 months, both noncontact and contact sports by 6 months, and collision sports by 12 months postoperatively. For all construct types, approximately 20% never allow return to collision sports, whereas all surgeons allow eventual return to contact and noncontact sports regardless of construct type. In addition to construct type, we found progressively distal LIV resulted in more surgeons never allowing return to collision sports, with 12% for selective thoracic fusion to T12/L1 versus 33% for posterior spinal fusion to L4. Most respondents also did not recommend formal postoperative physical therapy (78%). Of all surgeons surveyed, there was only one reported instrumentation failure/pullout without neurologic deficit after a patient went snowboarding 2 weeks postoperatively. Modern posterior instrumentation allows surgeons to recommend earlier return

ptk7 mutant zebrafish models of congenital and idiopathic scoliosis implicate dysregulated Wnt signalling in disease

PubMed Central

Hayes, Madeline; Gao, Xiaochong; Yu, Lisa X; Paria, Nandina; Henkelman, R. Mark; Wise, Carol A.; Ciruna, Brian

2014-01-01

Scoliosis is a complex genetic disorder of the musculoskeletal system, characterized by three-dimensional rotation of the spine. Curvatures caused by malformed vertebrae (congenital scoliosis (CS)) are apparent at birth. Spinal curvatures with no underlying vertebral abnormality (idiopathic scoliosis (IS)) most commonly manifest during adolescence. The genetic and biological mechanisms responsible for IS remain poorly understood due largely to limited experimental models. Here we describe zygotic ptk7 (Zptk7) mutant zebrafish, deficient in a critical regulator of Wnt signalling, as the first genetically defined developmental model of IS. We identify a novel sequence variant within a single IS patient that disrupts PTK7 function, consistent with a role for dysregulated Wnt activity in disease pathogenesis. Furthermore, we demonstrate that embryonic loss-of-gene function in maternal-zygotic ptk7 mutants (MZptk7) leads to vertebral anomalies associated with CS. Our data suggest novel molecular origins of, and genetic links between, congenital and idiopathic forms of disease. PMID:25182715

Automated comprehensive Adolescent Idiopathic Scoliosis assessment using MVC-Net.

PubMed

Wu, Hongbo; Bailey, Chris; Rasoulinejad, Parham; Li, Shuo

2018-05-18

Automated quantitative estimation of spinal curvature is an important task for the ongoing evaluation and treatment planning of Adolescent Idiopathic Scoliosis (AIS). It solves the widely accepted disadvantage of manual Cobb angle measurement (time-consuming and unreliable) which is currently the gold standard for AIS assessment. Attempts have been made to improve the reliability of automated Cobb angle estimation. However, it is very challenging to achieve accurate and robust estimation of Cobb angles due to the need for correctly identifying all the required vertebrae in both Anterior-posterior (AP) and Lateral (LAT) view x-rays. The challenge is especially evident in LAT x-ray where occlusion of vertebrae by the ribcage occurs. We therefore propose a novel Multi-View Correlation Network (MVC-Net) architecture that can provide a fully automated end-to-end framework for spinal curvature estimation in multi-view (both AP and LAT) x-rays. The proposed MVC-Net uses our newly designed multi-view convolution layers to incorporate joint features of multi-view x-rays, which allows the network to mitigate the occlusion problem by utilizing the structural dependencies of the two views. The MVC-Net consists of three closely-linked components: (1) a series of X-modules for joint representation of spinal structure (2) a Spinal Landmark Estimator network for robust spinal landmark estimation, and (3) a Cobb Angle Estimator network for accurate Cobb Angles estimation. By utilizing an iterative multi-task training algorithm to train the Spinal Landmark Estimator and Cobb Angle Estimator in tandem, the MVC-Net leverages the multi-task relationship between landmark and angle estimation to reliably detect all the required vertebrae for accurate Cobb angles estimation. Experimental results on 526 x-ray images from 154 patients show an impressive 4.04° Circular Mean Absolute Error (CMAE) in AP Cobb angle and 4.07° CMAE in LAT Cobb angle estimation, which demonstrates the MVC

Improved chest expansion in idiopathic scoliosis after intensive, multiple-modality, nonsurgical treatment in an adult.

PubMed

Hawes, M C; Brooks, W J

2001-08-01

This case report documents a substantial increase in chest wall expansion in a middle-aged woman with stable right thoracic spinal curvature due to idiopathic scoliosis. Treatment involved intensive psychological and mobilization therapies, including comprehensive manipulative medicine treatments and daily manual traction. Over an 8-year period, a 6-cm increase in resting chest circumference (in the absence of weight gain) and a 7.5-cm increase in chest expansion were correlated with a substantial reduction of incidence of respiratory infections.

Anterioposterior spinal curvatures and magnitude of asymmetry in the trunk in musicians playing the violin compared with nonmusicians.

PubMed

Barczyk-Pawelec, Katarzyna; Sipko, Tomasz; Demczuk-Włodarczyk, Ewa; Boczar, Agata

2012-05-01

Playing an instrument often requires a certain posture and asymmetric position that may affect the anteroposterior spinal curvatures and may lead to postural asymmetry. The aim of the study was to evaluate the spinal curvatures in the sagittal plane and the magnitude of asymmetries in the trunk in the frontal plane in a group of music students in comparison with a control group. The group of 67 students aged 20 to 26 years was made up of 2 subgroups: the musicians (violin playing students of the Academy of Music in Wroclaw) and the control group (physical therapy students who played no instruments). The examination included an interview, measuring of somatic characteristics, and evaluation of body posture by means of the photogrammetric method. The spinal curvatures of the instrumentalists in the sagittal plane differ from the control group mainly in terms of length and depth parameters. Compared with the control group, the musicians were characterized by statistically more significantly longer and deeper thoracic kyphosis (P < .01) and more shallow lumbar lordosis (P < .05), a greater angle of thoracic kyphosis (P < .005), and a smaller inclination angle of the thoracolumbar and lumbosacral section of the spine (P < .01). In the group of musicians, the asymmetries in the area of shoulders and waist triangles as well as the distance of the spinous processes from the C7 to S1 line were more frequent. Copyright © 2012 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.

Restrained Differential Growth: The Initiating Event of Adolescent Idiopathic Scoliosis?

PubMed

Crijns, Tom Joris; Stadhouder, Agnita; Smit, Theodoor Henri

2017-06-15

An experimental model study and a short review of literature. The purpose of this study was to explore a new hypothesis suggesting that the curvatures seen in adolescent idiopathic scoliosis (AIS) originate from restrained differential growth between the vertebral column and the surrounding musculo-ligamentary structures. Despite decades of research, there is no generally accepted theory on the physical origin of the severe spinal deformations seen in AIS. The prevailing theories tend to focus on left-right asymmetry, rotational instability, or the sagittal spinal profile in idiopathic scoliosis. We test our hypothesis with a physical model of the spine that simulates growth, counteracted by ligaments and muscles, modeled by tethers and springs. Growth of the spine is further restrained by an anterior band representing the thorax, the linea alba, and abdominal musculature. We also explore literature in search of molecular mechanisms that may induce differential growth. Differential growth in the restrained spine model first induces hypokyphosis and mild lateral bending of the thoracic spine, but then suddenly escalates into a scoliotic deformity, consistent with clinical observations of AIS. The band simulating the ventral structures of the body had a pivotal effect on sagittal curvature and the initiation of lateral bending and rotation. In literature, several molecular mechanisms were found that may explain the occurrence of differential growth between the spine and the musculo-ligamentary structures. While AIS is a three-dimensional deformation of the spine, it appears that restrained differential growth in the sagittal plane can result in lateral bending and rotation without a pre-existing left-right asymmetry. This supports the concept that AIS may result from a growth imbalance rather than a local anatomical defect. N/A.

Influence of implant rod curvature on sagittal correction of scoliosis deformity.

PubMed

Salmingo, Remel Alingalan; Tadano, Shigeru; Abe, Yuichiro; Ito, Manabu

2014-08-01

Deformation of in vivo-implanted rods could alter the scoliosis sagittal correction. To our knowledge, no previous authors have investigated the influence of implanted-rod deformation on the sagittal deformity correction during scoliosis surgery. To analyze the changes of the implant rod's angle of curvature during surgery and establish its influence on sagittal correction of scoliosis deformity. A retrospective analysis of the preoperative and postoperative implant rod geometry and angle of curvature was conducted. Twenty adolescent idiopathic scoliosis patients underwent surgery. Average age at the time of operation was 14 years. The preoperative and postoperative implant rod angle of curvature expressed in degrees was obtained for each patient. Two implant rods were attached to the concave and convex side of the spinal deformity. The preoperative implant rod geometry was measured before surgical implantation. The postoperative implant rod geometry after surgery was measured by computed tomography. The implant rod angle of curvature at the sagittal plane was obtained from the implant rod geometry. The angle of curvature between the implant rod extreme ends was measured before implantation and after surgery. The sagittal curvature between the corresponding spinal levels of healthy adolescents obtained by previous studies was compared with the implant rod angle of curvature to evaluate the sagittal curve correction. The difference between the postoperative implant rod angle of curvature and normal spine sagittal curvature of the corresponding instrumented level was used to evaluate over or under correction of the sagittal deformity. The implant rods at the concave side of deformity of all patients were significantly deformed after surgery. The average degree of rod deformation Δθ at the concave and convex sides was 15.8° and 1.6°, respectively. The average preoperative and postoperative implant rod angle of curvature at the concave side was 33.6° and 17.8�

Bipolar sealer device reduces blood loss and transfusion requirements in posterior spinal fusion for adolescent idiopathic scoliosis.

PubMed

Gordon, Zachary L; Son-Hing, Jochen P; Poe-Kochert, Connie; Thompson, George H

2013-01-01

Reducing perioperative blood loss and transfusion requirements is important in the operative treatment of idiopathic scoliosis. This can be achieved with special frames, cell saver systems, pharmacologic aspects, and other techniques. Recently there has been interest in bipolar sealer devices as an adjunct to traditional monopolar electrocautery. However, there is limited information on this device in pediatric spinal deformity surgery. We reviewed our experience with this device in a setting of a standard institutional operative carepath. Perioperative blood loss and transfusion requirements of 50 consecutive patients with adolescent idiopathic scoliosis undergoing a posterior spinal fusion and segmental spinal instrumentation and who had a bipolar sealer device used during their surgery was compared with a control group of the 50 preceding consecutive patients who did not. Anesthesia, surgical technique, use of intraoperative epsilon aminocaproic acid (Amicar), postoperative protocol, and indications for transfusions (hemoglobin≤7.0 g/dL) were identical in both groups. The preoperative demographics for the patients in both groups were statistically the same. The bipolar sealer group demonstrated a significant reduction in intraoperative estimated blood loss, total perioperative blood loss, volume of blood products transfused, and overall transfusion rate when compared with the control group. When subgroups consisting of only hybrid or all-pedicle screw constructs were considered individually, these findings remained consistent. There were no complications associated with the use of this device. Using the bipolar sealer device is a significant adjunct in decreasing perioperative blood loss and transfusion requirements in patients undergoing surgery for adolescent idiopathic scoliosis. Level III-retrospective comparative study.

Isola spinal instrumentation system for idiopathic scoliosis.

PubMed

Benli, I T; Akalin, S; Aydin, E; Baz, A; Citak, M; Kiş, M; Duman, E

2001-01-01

Since the definition of three-dimensional components of the scoliotic deformity, there have been important improvements in the surgical treatment of the problem. A derotation maneuver was proposed as a treatment option with CD instrumentation, but the reports of imbalance and decompensation with this system repopularized sublaminar wiring and translation as a corrective maneuver. Isola spinal instrumentation is one of the modern systems that utilizes vertebral translation instead of rod rotation. This study analyzes the results of 24 patients with idiopathic scoliosis who had been followed up for at least 2 years, and were surgically treated with titanium Isola Spinal Instrumentation in the Department of Orthopaedics and Traumatology, Ankara Social Security Hospital. Patients were grouped according to the King-Moe classification. Patients with type III, IV or V curves received only posterior instrumentation while this procedure followed anterior release and discectomy in the same session in patients with type I or II curves. A translation maneuver was utilized in the correction of scoliotic curves using the cantilever technique, either alone or supplemented by sublaminar wiring with Songer multifilament titanium cables. This study aimed to elucidate the effects of this technique in the frontal and sagittal plane curves and the trunk balance. The balance was analyzed clinically and radiologically by measurement of the lateral trunk shift (LT), shift of stable vertebra (SS), and shift of head (SH) in vertebral units (VU). The postoperative correction was significant in the frontal plane for all types of curves (p < 0.05). The postoperative correction was 80.9% +/- 9.5% in type III curves. Overall, the mean Cobb angle of the major curve value in the frontal plane was 66.9 degrees +/- 18.8 degrees, and it was corrected by 62.8% +/- 20.1%. The correction loss of Cobb angles in the frontal plane was 5.4 degrees +/- 5.5 degrees at the last follow-up visit. A normal

Radiology of spinal curvature

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

De Smet, A.A.

1985-01-01

This book offers the only comprehensive, concise summary of both the clinical and radiologic features of thoracic and lumbar spine deformity. Emphasis is placed on idiopathic scoliosis, which represents 85% of all patients with scoliosis, but less common areas of secondary scoliosis, kyphosis and lordosis are also covered.

Intrathecal morphine for postoperative analgesia in patients with idiopathic scoliosis undergoing posterior spinal fusion.

PubMed

Tripi, Paul A; Poe-Kochert, Connie; Potzman, Jennifer; Son-Hing, Jochen P; Thompson, George H

2008-09-15

A retrospective study of postoperative pain management with intrathecal morphine. Identify the dosing regimen of intrathecal morphine that safely and effectively provides postoperative analgesia with minimal complications in patients with idiopathic scoliosis undergoing posterior spinal fusion (PSF) and segmental spinal instrumentation (SSI). Postoperative pain after surgery for idiopathic scoliosis is a concern. Intrathecal morphine has been used to decrease pain. However, the most appropriate dose has not been determined. We retrospectively analyzed 407 consecutive patients with idiopathic scoliosis who underwent PSF and SSI at our institution from 1992 through 2006. Patients were divided into 3 groups based on the intrathecal morphine dose: no dose (n = 68); moderate dose of 9 to 19 microg/kg, mean 14 microg/kg (n = 293); and high dose of 20 microg/kg or greater, mean 24 microg/kg (n = 46). Data included demographics, Wong-Baker visual analog scale postoperative pain scores, postoperative intravenous morphine requirements, time to first rescue dose of intravenous morphine, and postoperative complications of pruritus, nausea/vomiting, respiratory depression, and pediatric intensive care unit (PICU) admission. The demographics of the 3 study groups showed no statistical differences. The mean Wong-Baker visual analog scale pain score in the post anesthesia care unit was 5.2, 0.5, and 0.2, and the mean time to first morphine rescue was 6.6, 16.7, and 22.9 hours, respectively. In the first 48 postoperative hours, respiratory depression occurred in 1 (1.5%), 8 (2.7%), and 7 (15.2%) patients, whereas PICU admission occurred in 0 (0%), 6 (2%), and 8 (17.4%) patients, respectively. The majority of PICU admissions were the result of respiratory depression. Frequency of pruritus and nausea/vomiting was similar in all 3 groups. Intrathecal morphine in the moderate dose range of 9 to 19 microg/kg (mean 14 microg/kg), provides safe and effective postoperative analgesia in the

Spine kinematics exhibited during the stop-jump by physically active individuals with adolescent idiopathic scoliosis and spinal fusion.

PubMed

Kakar, Rumit Singh; Li, Yumeng; Brown, Cathleen N; Kim, Seock-Ho; Oswald, Timothy S; Simpson, Kathy J

2018-01-01

Individuals with adolescent idiopathic scoliosis post spinal fusion often return to exercise and sport. However, the movements that individuals with spinal fusion for adolescent idiopathic scoliosis (SF-AIS) use to compensate for the loss of spinal flexibility during high-effort tasks are not known. The objective of this study was to compare the spinal kinematics of the trunk segments displayed during the stop-jump, a maximal effort task, between SF-AIS and healthy control groups. The study used a case-controlled design. Ten SF-AIS (physically active, posterior-approach spinal fusion: 11.2±1.9 fused segments, postop time: 2±.6 years) and nine control individuals, pair matched for gender, age (17.4±1.3 years and 20.6±1.5 years, respectively), mass (63.50±12.2 kg and 66. 40±10.9 kg), height (1.69±.09 m and 1.72±.08 m), and level of physical activity, participated in the study. Individuals with spinal fusion for adolescent idiopathic scoliosis and controls (CON) performed five acceptable trials of the stop-jump task. Spatial locations of 21 retroreflective trunk and pelvis markers were recorded via high-speed motion capture methodology. Mean differences and analysis of covariance (jump height=covariate, p<.05) were used to compare the groups' relative angle (RelAng) and segmental angle (SegAng) of the three trunk segments (trunk segments=upper trunk [C7-T8], middle trunk [MT: T9-T12], lower trunk [LT: L1-L5]) for each rotation plane in the three phases of interest (flight, stance, and the vertical flight phases). No significant group differences for jump height and RelAng were detected in the three phases of stop-jump. Individuals with spinal fusion for adolescent idiopathic scoliosis displayed 3.2° greater transverse plane RelAng of LT compared with CON (p=.059) in the stance phase. Group differences for RelAng ranged from 0° to 15.3°. For SegAng in the stance phase, LT demonstrated greater SegAng in the sagittal and frontal planes (mean

Effects of athletic training on the spinal curvature in child athletes.

PubMed

Betsch, Marcel; Furian, Thimm; Quack, Valentin; Rath, Björn; Wild, Michael; Rapp, Walter

2015-01-01

The purpose of this study was to examine the spinal posture in young athletes depending on training intensity. The spinal curvature of 245 children, age 8 to 12 years, was evaluated using rasterstereography. According to their weekly training time group 1 (mean age: 9.54 ± 1.18) did 2-6, group 2 (mean age: 9.49 ± 0.87) did 6-15 and group 3 (mean age: 9.68 ± 0.87) did over 15 hours of training. Group 1 had a significantly higher weight (p = 0.028) (33.86 ± 7. kg) than those of the more active groups (30.67 ± 6.49 kg and 29.46 ± 4.33 kg). The mean kyphotic angle decreased significantly (p < 0.001) with the amount of training per week from 46.86 ± 8.2° in group 1 to 40.08 ± 8° in group 3. We also found a significant decrease (p = 0.047) in lateral deviation with training from group 1 with 5.3 ± 3 mm to group 2 with 4.1 ± 1.6 mm. The results of our study suggest that higher training time can be associated with lower weight and decreases in thoracic kyphosis and lateral deviation of the spine.

Postural Rehabilitation for Adolescent Idiopathic Scoliosis during Growth

PubMed Central

Weiss, Hans-Rudolf; Moramarco, Marc Michael; Borysov, Maksym; Lee, Sang Gil; Nan, Xiaofeng; Moramarco, Kathryn Ann

2016-01-01

Long-term follow-up of untreated patients with adolescent idiopathic scoliosis (AIS) indicates that, with the exception of some extremely severe cases, AIS does not have a significant impact on quality of life and does not result in dire consequences. In view of the relatively benign nature of AIS and the long-term complications of surgery, the indications for treatment should be reviewed. Furthermore, recent studies have shown that scoliosis-specific exercises focusing on postural rehabilitation can positively influence the spinal curvatures in growing adolescents. Experiential postural re-education is a conservative, non-invasive approach, and its role in the management of AIS warrants further study. This article reviews current evidence for the inclusion of various forms of postural reeducation in the management of AIS. Recent comprehensive reviews have been researched including a manual and PubMed search for evidence regarding the effectiveness of physical/postural re-education/physiotherapy programs in growing AIS patients. This search revealed that there were few studies on the application of postural re-education in the management of AIS. These studies revealed that postural re-education in the form of exercise rehabilitation programs may have a positive influence on scoliosis; however, the various programs were difficult to compare. More research is necessary. There is at present Level 1 evidence for the effectiveness of Schroth scoliosis exercises in the management of AIS. Whether this evidence can be extrapolated to include other forms of scoliosis- pattern-specific exercises requires further investigation. Because corrective postures theoretically reduce the asymmetric loading of the spinal deformities and reverse the vicious cycle of spinal curvature progression, their integration into AIS programs may be beneficial and should be further examined. PMID:27340540

[Adolescent idiopathic scoliosis].

PubMed

2016-12-01

Adolescent idiopathic scoliosis is a 3D spinal deformity in frontal, sagittal and axial planes, with high relevance in the pediatric population especially in adolescents and females between 10 years of age and the end of growth spurt and skeletal maturity. The radiographic manifestation is a curve greater than 10° measured by Cobb method associated with vertebral rotation. "Idiopathic" diagnosis has to be done after neuroanatomical anomalies of the posterior cerebral fosa and spinal canal have been ruled out. The physical finding of a thoracic or lumbar hump is the clinical manifestation of vertebral rotation seen in a forward bending test (Adam's Test). It is recommended that all curves with a magnitude greater than 20° have to be controlled and treated by a spinal surgeon being observation, bracing and surgery the different treatment options based on the extent, progression of deformity and basically the clinical condition of the patient. Sociedad Argentina de Pediatría.

Accuracy of a Radiological Evaluation Method for Thoracic and Lumbar Spinal Curvatures Using Spinous Processes.

PubMed

Marchetti, Bárbara V; Candotti, Cláudia T; Raupp, Eduardo G; Oliveira, Eduardo B C; Furlanetto, Tássia S; Loss, Jefferson F

The purpose of this study was to assess a radiographic method for spinal curvature evaluation in children, based on spinous processes, and identify its normality limits. The sample consisted of 90 radiographic examinations of the spines of children in the sagittal plane. Thoracic and lumbar curvatures were evaluated using angular (apex angle [AA]) and linear (sagittal arrow [SA]) measurements based on the spinous processes. The same curvatures were also evaluated using the Cobb angle (CA) method, which is considered the gold standard. For concurrent validity (AA vs CA), Pearson's product-moment correlation coefficient, root-mean-square error, Pitman- Morgan test, and Bland-Altman analysis were used. For reproducibility (AA, SA, and CA), the intraclass correlation coefficient, standard error of measurement, and minimal detectable change measurements were used. A significant correlation was found between CA and AA measurements, as was a low root-mean-square error. The mean difference between the measurements was 0° for thoracic and lumbar curvatures, and the mean standard deviations of the differences were ±5.9° and 6.9°, respectively. The intraclass correlation coefficients of AA and SA were similar to or higher than the gold standard (CA). The standard error of measurement and minimal detectable change of the AA were always lower than the CA. This study determined the concurrent validity, as well as intra- and interrater reproducibility, of the radiographic measurements of kyphosis and lordosis in children. Copyright © 2017. Published by Elsevier Inc.

Association of spinal deformity and pelvic tilt with gait asymmetry in adolescent idiopathic scoliosis patients: Investigation of ground reaction force.

PubMed

Park, Yang Sun; Lim, Young Tae; Koh, Kyung; Kim, Jong Moon; Kwon, Hyun Joon; Yang, Ji Seung; Shim, Jae Kun

2016-07-01

Adolescent idiopathic scoliosis is a prevalent orthopedic problem in children ages 10 to 16years. Although genetic, physiological and biomechanical factors are considered to contribute to the onset and progression of adolescent idiopathic scoliosis, the underlying mechanisms are not yet clear. The purpose of this study was to investigate the association between spinal deformity and inter-leg ground reaction force asymmetry during walking in adolescent idiopathic scoliosis patients. Fourteen patients (3 males and 11 females) participated in this study. Maximum Cobb's angle, adjusted Cobb's angle, and pelvic tilt were calculated from X-ray images. Asymmetry indices between legs were also calculated from ground reaction force magnitude and time variables from their preferred speed walking. Pearson coefficients of correlation were used to investigate associations of asymmetry indices with angle variables. Asymmetry indices of ground reaction force magnitudes positively correlated with adjusted Cobb's angle and maximum Cobb's angle mainly during the peak of braking phase, average of braking phase, while asymmetry indices of ground reaction force time variables showed no significant correlation with adjusted or maximum Cobb's angle. In contrast, asymmetry indices of ground reaction force time variables positively correlated with pelvic tilt during stance phase. We concluded that the spinal deformity of adolescent idiopathic scoliosis patients estimated using the maximum and adjusted Cobb's angles is generally associated with greater asymmetry of ground reaction force magnitudes in walking, while the pelvic tilt is associated with the greater asymmetry of ground reaction force time variables. Copyright © 2016 Elsevier Ltd. All rights reserved.

Observation and Early Intervention in Mild Idiopathic Scoliosis via Corrective Exercises in Growing Children.

PubMed

Sy, Ng

2016-01-01

Idiopathic scoliosis afflicts 2-3% of the population. For mild curvatures, observation is the treatment of choice. Though this passive "wait and see" approach has been used for many years, the practice is inconsistent among different countries. In Anglo-Saxon countries where scoliosis specific exercises are not practised, observation is indicated for curvatures below 25° in growing children and adolescents. In countries, such as France, Germany, Italy and Poland where scoliosis specific corrective exercises are employed, only patients with no signs of maturity and with curvatures below 15° are treated by observation. Patients with curvatures between 15 - 25° are treated by scoliosis specific exercises. In view of the unpredictability of the progression of scoliosis curvatures in immature patients and the lack of knowledge of long term biomechanical repercussions of mild idiopathic scoliosis on lumbar spine and lower extremities, it is proposed that active intervention through scoliosis specific exercises rather than passive observation be employed in the treatment of mild adolescent idiopathic scoliosis.

Nonsurgical Management of Adolescent Idiopathic Scoliosis.

PubMed

Gomez, Jaime A; Hresko, M Timothy; Glotzbecker, Michael P

2016-08-01

Pediatric patient visits for spinal deformity are common. Most of these visits are for nonsurgical management of scoliosis, with approximately 600,000 visits for adolescent idiopathic scoliosis (AIS) annually. Appropriate management of scoliotic curves that do not meet surgical indication parameters is essential. Renewed enthusiasm for nonsurgical management of AIS (eg, bracing, physical therapy) exists in part because of the results of the Bracing in Adolescent Idiopathic Scoliosis Trial, which is the only randomized controlled trial available on the use of bracing for AIS. Bracing is appropriate for idiopathic curves between 20° and 40°, with successful control of these curves reported in >70% of patients. Patient adherence to the prescribed duration of wear is essential to maximize the effectiveness of the brace. The choice of brace type must be individualized according to the deformity and the patient's personality as well as the practice setting and brace availability.

A Comparison of Patient-Reported Outcome Measures Following Different Treatment Approaches for Adolescents with Severe Idiopathic Scoliosis: A Systematic Review

PubMed Central

Weiss, Hans-Rudolf; Chockalingam, Nachiappan; Kandasamy, Gokulakannan; Arnell, Tracey

2016-01-01

Adolescent idiopathic scoliosis (AIS) is a three-dimensional deformity of the spine which is usually not symptomatic and which can progress during growth and cause a surface deformity. In adulthood, if the final spinal curvature surpasses a certain critical threshold, the risk of health problems and curve progression is increased. Although surgery is usually recommended for curvatures exceeding 40° to 50° to stop curvature progression, recent reviews have shed some light on the long-term complications of such surgery and to the lack of evidence for such complicated procedures within the scientific literature. Furthermore, a number of patients are very fearful of having surgery and refuse this option or live in countries where specialist scoliosis surgery is not available. Other patients may be unable to afford the cost of specialist scoliosis surgery. For these patients the only choice is an alternative non-surgical treatment option. To examine the impact of different management options in patients with severe AIS, with a focus on trunk balance, progression of scoliosis, cosmetic issues, quality of life, disability, psychological issues, back pain, and adverse effects, at both the short-term (a few months) and the long-term (over 20 years). We searched CENTRAL, MEDLINE, EMBASE, CINHAL and two other databases up to January 2016 with no language limitations. We also checked the reference lists of relevant articles and conducted an extensive hand search of the grey literature. We searched for randomised controlled trials as well as prospective and retrospective controlled trials comparing spinal fusion surgery with no treatment or conservative treatment in AIS patients with a Cobb angle greater than 40°. We did not identify any evidence of superiority of effectiveness of operative compared to nonoperative interventions for patients with severe AIS. Within the present literature there is no clear evidence to suggest that a specific type of treatment is superior to

Association of microRNAs with Types of Leaf Curvature in Brassica rapa.

PubMed

Ren, Wenqing; Wang, Han; Bai, Jinjuan; Wu, Feijie; He, Yuke

2018-01-01

Many vegetable crops of Brassica rapa are characterized by their typical types of leaf curvature. Leaf curvature in the right direction and to the proper degree is important for the yield and quality of green vegetable products, when cultivated under stress conditions. Recent research has unveiled some of the roles of miRNAs in Brassica crops such as how they regulate the timing of leafy head initiation and shape of the leafy head. However, the molecular mechanism underlying the variability in leaf curvature in B. rapa remains unclear. We tested the hypothesis that the leaf curvature of B. rapa is affected by miRNA levels. On the basis of leaf phenotyping, 56 B. rapa accessions were classified into five leaf curvature types, some of which were comparable to miRNA mutants of Arabidopsis thaliana in phenotype. Higher levels of miR166 and miR319a expression were associated with downward curvature and wavy margins, respectively. Overexpression of the Brp - MIR166g-1 gene caused rosette leaves to change from flat to downward curving and folding leaves to change from upward curving to flat, leading to the decrease in the number of incurved leaves and size of the leafy head. Our results reveal that miRNAs affect the types of leaf curvature in B. rapa . These findings provide insight into the relationship between miRNAs and variation in leaf curvature.

Association of microRNAs with Types of Leaf Curvature in Brassica rapa

PubMed Central

Ren, Wenqing; Wang, Han; Bai, Jinjuan; Wu, Feijie; He, Yuke

2018-01-01

Many vegetable crops of Brassica rapa are characterized by their typical types of leaf curvature. Leaf curvature in the right direction and to the proper degree is important for the yield and quality of green vegetable products, when cultivated under stress conditions. Recent research has unveiled some of the roles of miRNAs in Brassica crops such as how they regulate the timing of leafy head initiation and shape of the leafy head. However, the molecular mechanism underlying the variability in leaf curvature in B. rapa remains unclear. We tested the hypothesis that the leaf curvature of B. rapa is affected by miRNA levels. On the basis of leaf phenotyping, 56 B. rapa accessions were classified into five leaf curvature types, some of which were comparable to miRNA mutants of Arabidopsis thaliana in phenotype. Higher levels of miR166 and miR319a expression were associated with downward curvature and wavy margins, respectively. Overexpression of the Brp-MIR166g-1 gene caused rosette leaves to change from flat to downward curving and folding leaves to change from upward curving to flat, leading to the decrease in the number of incurved leaves and size of the leafy head. Our results reveal that miRNAs affect the types of leaf curvature in B. rapa. These findings provide insight into the relationship between miRNAs and variation in leaf curvature. PMID:29467771

Aortic curvature as a predictor of intraoperative type Ia endoleak.

PubMed

Schuurmann, Richte C L; Ouriel, Kenneth; Muhs, Bart E; Jordan, William D; Ouriel, Richard L; Boersen, Johannes T; de Vries, Jean-Paul P M

2016-03-01

Hostile infrarenal neck characteristics are associated with complications such as type Ia endoleak after endovascular aneurysm repair. Aortic neck angulation has been identified as one such characteristic, but its association with complications has not been uniform between studies. Neck angulation assumes triangular oversimplification of the aortic trajectory, which may explain conflicting findings. By contrast, aortic curvature is a measurement that includes the bending rate and tortuosity and may provide better predictive value for neck complications. Data were retrieved from the Heli-FX (Aptus Endosystems, Inc, Sunnyvale, Calif) Aortic Securement System Global Registry (ANCHOR). One cohort included patients who presented with intraoperative endoleak type Ia at the completion angiogram as the indication for EndoAnchors (Aptus Endosystems), and a second cohort comprised those without intraoperative or late type Ia endoleak (controls). The aortic trajectory was divided into six segments with potentially different influence on the stent graft performance: suprarenal, juxtarenal, and infrarenal aortic neck (-30 to -10 mm, -10 to 10 mm, and 10-30 mm from the lowest renal artery, respectively), the entire aortic neck, aneurysm sac, and terminal aorta (20 mm above the bifurcation to the bifurcation). Maximum and average curvature were automatically calculated over the six segments by proprietary custom software. Aortic curvature was compared with other standard neck characteristics, including neck length, neck diameter, maximum aneurysm sac diameter, neck thrombus and calcium thickness and circumference, suprarenal angulation, infrarenal angulation, and the neck tortuosity index. Independent risk factors for intraoperative type Ia endoleak were identified using backwards stepwise logistic regression. For the variables in the final regression model, suitable cutoff values in relation to the prediction of acute type Ia endoleak were defined with the area under the

Infection after anterior spinal fusion for idiopathic scoliosis using the Cotrel-Dubousset-Hopf system: A clinical case series of three patients.

PubMed

Tolk, Jaap J; Willems, Paul C; Punt, Ilona M; van Rhijn, Lodewijk W; van Ooij, André

2016-01-01

Three patients with late-onset infection after multilevel instrumented anterior spinal fusion for idiopathic scoliosis, using the Cotrel-Dubousset-Hopf (CDH) system, are presented. The CDH-system is an anterior instrumentation with high biomechanical stability and rigidity, ensuring a stable primary fixation. Unlike after posterior spinal fusion, infection after anterior spinal fusion (ASF) for idiopathic scoliosis has rarely been reported. The files of three patients who developed an infection after ASF for scoliosis using the CDH-system, were reviewed. The clinical presentation and diagnostic and therapeutic options are discussed. All three patients had a late-onset infection of the CDH-system, which was difficult to diagnose because of nonspecific symptoms. Radiographs and technetium bone scan appeared to be of low value. When an abscess was present, this could accurately be diagnosed with MRI or CT imaging. Operative treatment with implant removal and antibiotic therapy was successful in all cases. Late onset infections after ASF using the CDH-system presented with few and nonspecific symptoms. The clinical presentation was mainly characterized by vague abdominal- or back-pain after an interval of normal postoperative recovery, moderately raised infection parameters and inconclusive findings with imaging modalities. As treatment, implant removal, debridement and parenteral antibiotics are recommended. It should be noted though that implant removal poses serious risks for vascular and visceral structures.

Factors favoring regain of the lost vertical spinal height through posterior spinal fusion in adolescent idiopathic scoliosis.

PubMed

Shi, Benlong; Mao, Saihu; Xu, Leilei; Sun, Xu; Liu, Zhen; Zhu, Zezhang; Lam, Tsz Ping; Cheng, Jack Cy; Ng, Bobby; Qiu, Yong

2016-07-04

Height gain is a common beneficial consequence following correction surgery in adolescent idiopathic scoliosis (AIS), yet little is known concerning factors favoring regain of the lost vertical spinal height (SH) through posterior spinal fusion. A consecutive series of AIS patients from February 2013 to August 2015 were reviewed. Surgical changes in SH (ΔSH), as well as the multiple coronal and sagittal deformity parameters were measured and correlated. Factors associated with ΔSH were identified through Pearson correlation analysis and multivariate regression analysis. A total of 172 single curve and 104 double curve patients were reviewed. The ΔSH averaged 2.5 ± 0.9 cm in single curve group and 2.9 ± 1.0 cm in double curve group. The multivariate regression analysis revealed the following pre-operative variables contributed significantly to ΔSH: pre-op Cobb angle, pre-op TK (single curve group only), pre-op GK (double curve group only) and pre-op LL (double curve group only) (p < 0.05). Thus change in height (in cm) = 0.044 × (pre-op Cobb angle) + 0.012 × (pre-op TK) (Single curve, adjusted R(2) = 0.549) or 0.923 + 0.021 × (pre-op Cobb angle1) + 0.028 × (pre-op Cobb angle2) + 0.015 × (pre-op GK)-0.012 × (pre-op LL) (Double curve, adjusted R(2) = 0.563). Severer pre-operative coronal Cobb angle and greater sagittal curves were beneficial factors favoring more contribution to the surgical lengthening effect in vertical spinal height in AIS.

Model-based registration for assessment of spinal deformities in idiopathic scoliosis

NASA Astrophysics Data System (ADS)

Forsberg, Daniel; Lundström, Claes; Andersson, Mats; Knutsson, Hans

2014-01-01

Detailed analysis of spinal deformity is important within orthopaedic healthcare, in particular for assessment of idiopathic scoliosis. This paper addresses this challenge by proposing an image analysis method, capable of providing a full three-dimensional spine characterization. The proposed method is based on the registration of a highly detailed spine model to image data from computed tomography. The registration process provides an accurate segmentation of each individual vertebra and the ability to derive various measures describing the spinal deformity. The derived measures are estimated from landmarks attached to the spine model and transferred to the patient data according to the registration result. Evaluation of the method provides an average point-to-surface error of 0.9 mm ± 0.9 (comparing segmentations), and an average target registration error of 2.3 mm ± 1.7 (comparing landmarks). Comparing automatic and manual measurements of axial vertebral rotation provides a mean absolute difference of 2.5° ± 1.8, which is on a par with other computerized methods for assessing axial vertebral rotation. A significant advantage of our method, compared to other computerized methods for rotational measurements, is that it does not rely on vertebral symmetry for computing the rotational measures. The proposed method is fully automatic and computationally efficient, only requiring three to four minutes to process an entire image volume covering vertebrae L5 to T1. Given the use of landmarks, the method can be readily adapted to estimate other measures describing a spinal deformity by changing the set of employed landmarks. In addition, the method has the potential to be utilized for accurate segmentations of the vertebrae in routine computed tomography examinations, given the relatively low point-to-surface error.

Disruption of biomineralization pathways in spinal tissues of a mouse model of diffuse idiopathic skeletal hyperostosis.

PubMed

Ii, Hisataka; Warraich, Sumeeta; Tenn, Neil; Quinonez, Diana; Holdsworth, David W; Hammond, James R; Dixon, S Jeffrey; Séguin, Cheryle A

2016-09-01

Equilibrative nucleoside transporter 1 (ENT1) mediates passage of adenosine across the plasma membrane. We reported previously that mice lacking ENT1 (ENT1(-/-)) exhibit progressive ectopic mineralization of spinal tissues resembling diffuse idiopathic skeletal hyperostosis (DISH) in humans. Here, we investigated mechanisms underlying aberrant mineralization in ENT1(-/-) mice. Micro-CT revealed ectopic mineralization of spinal tissues in both male and female ENT1(-/-) mice, involving the annulus fibrosus of the intervertebral discs (IVDs) of older mice. IVDs were isolated from wild-type and ENT1(-/-) mice at 2months of age (prior to disc mineralization), 4, and 6months of age (disc mineralization present) and processed for real-time PCR, cell isolation, or histology. Relative to the expression of ENTs in other tissues, ENT1 was the primary nucleoside transporter expressed in wild-type IVDs and mediated the functional uptake of [(3)H]2-chloroadenosine by annulus fibrosus cells. No differences in candidate gene expression were detected in IVDs from ENT1(-/-) and wild-type mice at 2 or 4months of age. However, at 6months of age, expression of genes that inhibit biomineralization Mgp, Enpp1, Ank, and Spp1 were reduced in IVDs from ENT1(-/-) mice. To assess whether changes detected in ENT1(-/-) mice were cell autonomous, annulus fibrosus cell cultures were established. Compared to wild-type cells, cells isolated from ENT1(-/-) IVDs at 2 or 6months of age demonstrated greater activity of alkaline phosphatase, a promoter of biomineralization. Cells from 2-month-old ENT1(-/-) mice also showed greater mineralization than wild-type. Interestingly, altered localization of alkaline phosphatase activity was detected in the inner annulus fibrosus of ENT1(-/-) mice in vivo. Alkaline phosphatase activity, together with the marked reduction in mineralization inhibitors, is consistent with the mineralization of IVDs seen in ENT1(-/-) mice at older ages. These findings establish that

The posterior skeletal thorax: rib-vertebral angle and axial vertebral rotation asymmetries in adolescent idiopathic scoliosis.

PubMed

Burwell, R G; Aujla, R K; Freeman, B J C; Dangerfield, P H; Cole, A A; Kirby, A S; Polak, F J; Pratt, R K; Moulton, A

2008-01-01

The deformity of the ribcage in thoracic adolescent idiopathic scoliosis (AIS) is viewed by most as being secondary to the spinal deformity, though a few consider it primary or involved in curve aggravation. Those who consider it primary ascribe pathogenetic significance to rib-vertebra angle asymmetry. In thoracic AIS, supra-apical rib-vertebra angle differences (RVADs) are reported to be associated with the severity of the Cobb angle. In this paper we attempt to evaluate rib and spinal pathomechanisms in thoracic and thnoracolumbar AIS using spinal radiographs and real-time ultrasound. On the radiographs by costo-vertebral angle asymmetries (rib-vertebral angle differences RVADs, and rib-spinal angle differences RSADs), apical vertebral rotation (AV) and apical vertebral translation (AVT) were measured; and by ultrasound, spine-rib rotation differences (SRRDs) were estimated. RVADs are largest at two and three vertebral levels above the apex where they correlate significantly and positively with Cobb angle and AVT but not AVR. In right thoracic AIS, the cause(s) of the RVA asymmetries is unknown: it may result from trunk muscle imbalance, or from ribs adjusting passively within the constraint of the fourth column of the spine to increasing spinal curvature from whatever cause. Several possible mechanisms may drive axial vertebral rotation including, biplanar spinal asymmetry, relative anterior spinal overgrowth, dorsal shear forces in the presence of normal vertebral axial rotation, asymmetry of rib linear growth, trunk muscle imbalance causing rib-vertebra angle asymmetry weakening the spinal rotation-defending system of bipedal gait, and CNS mechanisms.

Current concepts and controversies on adolescent idiopathic scoliosis: Part I.

PubMed

Sud, Alok; Tsirikos, Athanasios I

2013-03-01

Adolescent idiopathic scoliosis is the most common spinal deformity encountered by General Orthopaedic Surgeons. Etiology remains unclear and current research focuses on genetic factors that may influence scoliosis development and risk of progression. Delayed diagnosis can result in severe deformities which affect the coronal and sagittal planes, as well as the rib cage, waistline symmetry, and shoulder balance. Patient's dissatisfaction in terms of physical appearance and mechanical back pain, as well as the risk for curve deterioration are usually the reasons for treatment. Conservative management involves mainly bracing with the aim to stop or slow down scoliosis progression during growth and if possible prevent the need for surgical treatment. This is mainly indicated in young compliant patients with a large amount of remaining growth and progressive curvatures. Scoliosis correction is indicated for severe or progressive curves which produce significant cosmetic deformity, muscular pain, and patient discontent. Posterior spinal arthrodesis with Harrington instrumentation and bone grafting was the first attempt to correct the coronal deformity and replace in situ fusion. This was associated with high pseudarthrosis rates, need for postoperative immobilization, and flattening of sagittal spinal contour. Segmental correction techniques were introduced along with the Luque rods, Harri-Luque, and Wisconsin systems. Correction in both coronal and sagittal planes was not satisfactory and high rates of nonunion persisted until Cotrel and Dubousset introduced the concept of global spinal derotation. Development of pedicle screws provided a powerful tool to correct three-dimensional vertebral deformity and opened a new era in the treatment of scoliosis.

Potential Involvement of Obesity-Associated Chronic Inflammation in the Pathogenesis of Idiopathic Spinal Epidural Lipomatosis.

PubMed

Fujita, Nobuyuki; Hosogane, Naobumi; Hikata, Tomohiro; Iwanami, Akio; Watanabe, Kota; Shiono, Yuta; Okada, Eijiro; Ishikawa, Masayuki; Tsuji, Takashi; Shimoda, Masayuki; Horiuchi, Keisuke; Nakamura, Masaya; Matsumoto, Morio; Ishii, Ken

2016-12-01

Multicenter case-control study. To characterize the pathogenesis of idiopathic spinal epidural lipomatosis (SEL). SEL is often associated with the history of steroid use or endocrine disorders; however, the pathogenesis of idiopathic SEL remains poorly understood. Sixteen patients who underwent lumbar decompression surgery due to severe idiopathic SEL were included in the study (L group, 15 men and 1 woman; mean age, 71.5 yrs). Fifteen patients without SEL, who underwent decompression surgery for lumbar canal stenosis, were selected as controls (C group, 14 men and 1 woman; mean age, 70.3 yrs). The following parameters were analyzed in these two groups: body mass index (BMI), medical history, histology, the size of adipocytes in the epidural fat (EF) tissues, and the expression level of the transcripts for adiponectin, leptin, tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-8. The mean BMI of the L group was significantly higher than that of the C group (29.1 vs. 25.2 kg/m, P = 0.006), and there was a significant correlation between BMI and the width of EF in both groups. The average adipocyte size in the EF was significantly larger in the L group than in the C group (2846.8 vs. 1699.0 μm, P = 0.017). Furthermore, the expression levels of the transcripts for TNF-α and IL-1β in the L group were significantly higher than those in the C group [2.59-fold increase (P = 0.023) and 2.60-fold increase (P = 0.015), respectively]. Our data suggest that the pathogenesis of idiopathic SEL is associated with obesity. In addition, the increased expression of two major inflammatory cytokines in the EF in the L group may indicate that SEL is causally related to chronic inflammation. 3.

Lumbar spine disc heights and curvature: upright posture vs. supine compression harness

NASA Technical Reports Server (NTRS)

Lee, Shi-Uk; Hargens, Alan R.; Fredericson, Michael; Lang, Philipp K.

2003-01-01

INTRODUCTION: Spinal lengthening in microgravity is thought to cause back pain in astronauts. A spinal compression harness can compress the spine to eliminate lengthening but the loading condition with harness is different than physiologic conditions. Our purpose was to compare the effect of spine compression with a harness in supine position on disk height and spinal curvature in the lumbar spine to that of upright position as measured using a vertically open magnetic resonance imaging system. METHODS: Fifteen healthy subjects volunteered. On day 1, each subject lay supine for an hour and a baseline scan of the lumbar spine was performed. After applying a load of fifty percent of body weight with the harness for thirty minutes, the lumbar spine was scanned again. On day 2, after a baseline scan, a follow up scan was performed after kneeling for thirty minutes within the gap between two vertically oriented magnetic coils. Anterior and posterior disk heights, posterior disk bulging, and spinal curvature were measured from the baseline and follow up scans. RESULTS: Anterior disk heights increased and posterior disk heights decreased compared with baseline scans both after spinal compression with harness and upright posture. The spinal curvature increased by both loading conditions of the spine. DISCUSSION: The spinal compression with specially designed harness has the same effect as the physiologic loading of the spine in the kneeling upright position. The harness shows some promise as a tool to increase the diagnostic capabilities of a conventional MR system.

Changes in spinal alignment.

PubMed

Veintemillas Aráiz, M T; Beltrán Salazar, V P; Rivera Valladares, L; Marín Aznar, A; Melloni Ribas, P; Valls Pascual, R

2016-04-01

Spinal misalignments are a common reason for consultation at primary care centers and specialized departments. Misalignment has diverse causes and is influenced by multiple factors: in adolescence, the most frequent misalignment is scoliosis, which is idiopathic in 80% of cases and normally asymptomatic. In adults, the most common cause is degenerative. It is important to know the natural history and to detect factors that might predict progression. The correct diagnosis of spinal deformities requires specific imaging studies. The degree of deformity determines the type of treatment. The aim is to prevent progression of the deformity and to recover the flexibility and balance of the body. Copyright © 2016 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

Concomitant idiopathic hypertrophic spinal pachymeningitis and Guillain-Barré syndrome in a patient: coincidence or a triggering mechanism?

PubMed

Olubajo, Farouk; Yermakova, Tatyana; Highley, J Robin; Arzoglou, Vasileios

2017-09-01

Idiopathic hypertrophic spinal pachymeningitis (IHSP), a rare diffuse inflammatory thickening of the dura mater, and Guillain-Barré syndrome (GBS) are known entities but they have never been reported as concomitant diagnoses. To their knowledge, the authors present the first reported case in the international literature with supportive evidence for both IHSP (based on MRI, intraoperative, and histological findings) and GBS (based on history, clinical examination, and electrophysiological findings). They review the literature on IHSP and the diagnostic criteria for GBS, with the view of identifying a possible causative connection.

Patient-controlled Intermittent Epidural Bolus Versus Epidural Infusion for Posterior Spinal Fusion After Adolescent Idiopathic Scoliosis: Prospective, Randomized, Double-blinded Study.

PubMed

Erdogan, Mehmet Ali; Ozgul, Ulku; Ucar, Muharrem; Korkmaz, Mehmet Fatih; Aydogan, Mustafa Said; Ozkan, Ahmet Selim; Colak, Cemil; Durmus, Mahmut

2017-06-15

A prospective, randomized, double-blinded study. The aim of this study was to compare the efficacy and side effects of patient-controlled intermittent bolus epidural analgesia (PCIEA) and patient-controlled continuous epidural analgesia (PCCEA) for postoperative pain control in adolescent idiopathic scoliosis. Epidural analgesia is an accepted efficacious and safe procedure for postoperative pain management in scoliosis surgery. However, the PCIEA has not been adequately investigated for postoperative pain control in adolescent idiopathic scoliosis. Forty-seven patients, 8 to 18 years of age, who were undergoing posterior spinal fusion for idiopathic scoliosis were randomized to either the PCIEA or PCCEA group. An epidural catheter was inserted by a surgeon under direct visualization. The PCIEA group received 0.2 mg/mL of morphine, 0.25 mL/kg of morphine bolus, additional doses of 0.25 mL/kg morphine with a 1-hour lockout given by patient-controlled demand, and no infusion. The PCCEA group received the following: 0.2 mg/mL morphine, an initial morphine loading set at 0.1 mL/kg, followed by a 0.05 mL/kg/h continuous infusion of morphine, and a 0.025 mL/kg bolus dose of morphine. There was a 30-minute lockout interval. The primary outcome was morphine usage. The secondary outcomes were pain score, postoperative nausea and vomiting, and pruritus. Cumulative morphine consumption was lower in the PCIEA group than in the PCCEA group. Both methods provided effective pain control. There were no differences in pain scores between the groups. Postoperative nausea, vomiting, and pruritus were lower in the PCIEA group. The two epidural analgesia techniques studied are both safe and effective methods for postoperative pain control after posterior spinal fusion in idiopathic scoliosis. Nausea, vomiting and pruritus were considerably higher in the PCCEA group. Concerns regarding side effects associated with epidural opioids can be avoided by an intermittent bolus

The role of Amicar in same-day anterior and posterior spinal fusion for idiopathic scoliosis.

PubMed

Thompson, George H; Florentino-Pineda, Ivan; Poe-Kochert, Connie; Armstrong, Douglas G; Son-Hing, Jochen P

2008-09-15

A retrospective study of the effectiveness of Amicar (epsilon aminocaproic acid). Evaluate the effectiveness of Amicar in decreasing perioperative blood loss and transfusion requirements in same-day anterior (ASF) and posterior spinal fusion (PSF) with segmental spinal instrumentation (SSI) for idiopathic scoliosis. Preliminary prospective, prospective randomized double-blind, and fibrinogen studies have demonstrated Amicar to be effective in decreasing perioperative blood loss in patients with idiopathic scoliosis undergoing PSF with SSI. Increased fibrinogen secretion is a possible explanation. There were 73 consecutive patients divided into 3 study groups based on the administration of Amicar: Group 1 (n = 16), no Amicar; Group 2 (n = 18), Amicar for the PSF with SSI only; and Group 3 (n = 39), Amicar for both ASF and PSF with SSI. All patients were managed using the same general anesthesia technique, intraoperative procedure, postoperative care path, and indications for transfusion (hemoglobin <7 g/dL). Total perioperative blood loss (estimated intraoperative blood loss for both procedures and measured postoperative chest tube and PSF wound suction drainage) and total transfusion requirements between groups were compared using one-way ANOVA. There were statistically significant decreases in mean estimated intraoperative PSF with SSI, total perioperative blood loss, and transfusion requirements in the 2 Amicar groups. However, Amicar had no significant effect on estimated intraoperative ASF blood loss, chest tube drainage, or PSF wound suction drainage. Total perioperative blood loss and transfusion requirements (cell saver, autologous, directed, and allogeneic blood) were: 3442.8 +/- 1344.0 mL and 1537.1 +/- 905.1 mL in Group 1; 2089.8 +/- 684.0 mL and 485.2 +/- 349.8 mL in Group 2; and 2184.1 +/- 1163.7 mL and 531.5 +/- 510.5 mL in Group 3. There were no Amicar related complications. Amicar was highly effective in decreasing total perioperative blood loss and

Spinal fusion limits upper body range of motion during gait without inducing compensatory mechanisms in adolescent idiopathic scoliosis patients.

PubMed

Holewijn, R M; Kingma, I; de Kleuver, M; Schimmel, J J P; Keijsers, N L W

2017-09-01

Previous studies show a limited alteration of gait at normal walking speed after spinal fusion surgery for adolescent idiopathic scoliosis (AIS), despite the presumed essential role of spinal mobility during gait. This study analyses how spinal fusion affects gait at more challenging walking speeds. More specifically, we investigated whether thoracic-pelvic rotations are reduced to a larger extent at higher gait speeds and whether compensatory mechanisms above and below the stiffened spine are present. 18 AIS patients underwent gait analysis at increasing walking speeds (0.45 to 2.22m/s) before and after spinal fusion. The range of motion (ROM) of the upper (thorax, thoracic-pelvic and pelvis) and lower body (hip, knee and ankle) was determined in all three planes. Spatiotemporal parameters of interest were stride length and cadence. Spinal fusion diminished transverse plane thoracic-pelvic ROM and this difference was more explicit at higher walking speeds. Transversal pelvis ROM was also decreased but this effect was not affected by speed. Lower body ROM, step length and cadence remained unaffected. Despite the reduction of upper body ROM after spine surgery during high speed gait, no altered spatiotemporal parameters or increased compensatory ROM above or below the fusion (i.e. in the shoulder girdle or lower extremities) was identified. Thus, it remains unclear how patients can cope so well with such major surgery. Future studies should focus on analyzing the kinematics of individual spinal levels above and below the fusion during gait to investigate possible compensatory mechanisms within the spine. Copyright © 2017 Elsevier B.V. All rights reserved.

Spinal fusion

MedlinePlus

... of another Abnormal curvatures, such as those from scoliosis or kyphosis Arthritis in the spine, such as ... Spine surgery - discharge Surgical wound care - open Images Scoliosis Spinal fusion - series References Bennett EE, Hwang L, ...

Idiopathic scrotal calcinosis.

PubMed

Celik, Orcun; Ipekci, Tumay; Kazimoglu, Hatem

2013-12-01

Idiopathic scrotal calcinosis is a rare scrotal benign disease. Its distinct features are painless, non-pruritic, semi-soft palpable calcific transdermal nodules. We report a 42-year-old-man with asymptomatic multiple calcified scrotal skin nodules for 10 years. Under spinal anesthesia, the affected scrotal skin was excised and the nodules removed. We aim to explain the etiology, pathophysiology, diagnosis, and treatment modalities of this rare disease.

Concepts on the pathogenesis of adolescent idiopathic scoliosis. Bone growth and mass, vertebral column, spinal cord, brain, skull, extra-spinal left-right skeletal length asymmetries, disproportions and molecular pathogenesis.

PubMed

Burwell, R Geoffrey; Dangerfield, Peter H; Freeman, Brian J C

2008-01-01

There is no generally accepted scientific theory for the causes of adolescent idiopathic scoliosis (AIS). Encouraging advances thought to be related to AIS pathogenesis have recently been made in several fields including anthropometry of bone growth, bone mass, spinal growth modulation, extra-spinal left-right skeletal length asymmetries and disproportions, magnetic resonance imaging of vertebral column, spinal cord, brain, skull, and molecular pathogenesis. These advances are leading to the evaluation of new treatments including attempts at minimally invasive surgery on the spine and peri-apical ribs. Several concepts of AIS are outlined indicating their clinical applications but not their research potential. The concepts, by derivation morphological, molecular and mathematical, are addressed in 15 sections: 1) initiating and progressive factors; 2) relative anterior spinal overgrowth; 3) dorsal shear forces that create axial rotational instability; 4) rotational preconstraint; 5) uncoupled, or asynchronous, spinal neuro-osseous growth; 6) brain, nervous system and skull; 7) a novel neuro-osseous escalator concept based on a putative abnormality of two normal polarized processes namely, a) increasing skeletal dimensions, and b) the CNS body schema - both contained within a neuro-osseous timing of maturation (NOTOM) concept; 8) transverse plane pelvic rotation, skeletal asymmetries and developmental theory; 9) thoraco-spinal concept; 10) origin in contracture at the hips; 11) osteopenia; 12) melatonin deficiency; 13) systemic melatonin-signaling pathway dysfunction; 14) platelet calmodulin dysfunction; and 15) biomechanical spinal growth modulation. From these concepts, a collective model for AIS pathogenesis is formulated. The central concept of this model includes the body schema of the neural systems, widely-studied in adults, that control normal posture and coordinated movements with frames of reference in the posterior parietal cortex. The escalator concept

Spinal deformities in a wild line of Poecilia wingei bred in captivity: report of cases and review of the literature.

PubMed

Arbuatti, Alessio; Della Salda, Leonardo; Romanucci, Mariarita

2013-03-01

To describe the occurrence of various spinal deformations in a captive-bred wild line of Poecilia wingei (P. wingei). Fish belonging to a wild line of P. wingei caught from Laguna de Los Patos, Venezuela, were bred in an aquarium home-breeding system during a period of three years (2006-2009). The spinal curvature was observed to study spinal deformities in P. wingei. Out of a total of 600 fish, 22 showed different types of deformities (scoliosis, lordosis, kyphosis), with a higher incidence in females. Growth, swimming and breeding of deformed fish were generally normal. Possible causes for spinal curvature in fish are discussed on the basis of the current literature. While it is not possible to determine the exact cause(s) of spinal deformities observed in the present study, traumatic injuries, nutritional imbalances, genetic defects or a combination of these factors can be supposed to be involved in the pathogenesis of such lesions.

Accuracy and reliability of coronal and sagittal spinal curvature data based on patient-specific three-dimensional models created by the EOS 2D/3D imaging system.

PubMed

Somoskeöy, Szabolcs; Tunyogi-Csapó, Miklós; Bogyó, Csaba; Illés, Tamás

2012-11-01

Three-dimensional (3D) deformations of the spine are predominantly characterized by two-dimensional (2D) angulation measurements in coronal and sagittal planes, using anteroposterior and lateral X-ray images. For coronal curves, a method originally described by Cobb and for sagittal curves a modified Cobb method are most widely used in practice, and these methods have been shown to exhibit good-to-excellent reliability and reproducibility, carried out either manually or by computer-based tools. Recently, an ultralow radiation dose-integrated radioimaging solution was introduced with special software for realistic 3D visualization and parametric characterization of the spinal column. Comparison of accuracy, correlation of measurement values, intraobserver and interrater reliability of methods by conventional manual 2D and sterEOS 3D measurements in a routine clinical setting. Retrospective nonrandomized study of diagnostic X-ray images created as part of a routine clinical protocol of eligible patients examined at our clinic during a 30-month period between July 2007 and December 2009. In total, 201 individuals (170 females, 31 males; mean age, 19.88 years) including 10 healthy athletes with normal spine and patients with adolescent idiopathic scoliosis (175 cases), adult degenerative scoliosis (11 cases), and Scheuermann hyperkyphosis (5 cases). Overall range of coronal curves was between 2.4° and 117.5°. Analysis of accuracy and reliability of measurements were carried out on a group of all patients and in subgroups based on coronal plane deviation: 0° to 10° (Group 1, n=36), 10° to 25° (Group 2, n=25), 25° to 50° (Group 3, n=69), 50° to 75° (Group 4, n=49), and more than 75° (Group 5, n=22). Coronal and sagittal curvature measurements were determined by three experienced examiners, using either traditional 2D methods or automatic measurements based on sterEOS 3D reconstructions. Manual measurements were performed three times, and sterEOS 3D

Characteristics of lateral electrical surface stimulation (LESS) and its effect on the degree of spinal deformity in idiopathic scoliosis

NASA Astrophysics Data System (ADS)

Kowalski, Ireneusz M.; Palko, Tadeusz; Pasniczek, Roman; Szarek, Jozef

2009-01-01

Clinical studies were carried out in the period of 2003-2006 at the Provincial Children's Rehabilitation Hospital in Ameryka near Olsztyn (Poland). The study involved a group of children and youth exhibiting spinal deformity progression in idiopathic scoliosis (IS) of more than 5° per year according to the Cobb scale. Four hundred and fifty patients between 4 and 15 years of age were divided into three groups (n = 150). Group I and group II received 2-hour and 9-hour lateral electrical surface stimulation (LESS), respectively, whereas group III (control) was treated only with corrective exercises for 30 minutes twice a day. LESS was performed with the use of a battery-operated SCOL-2 stimulator manufactured by Elmech, Warsaw, Poland. The effectiveness of this method was confirmed in the treatment of spinal IS in children and youth, especially when the initial spinal deformity did not exceed 20° according to the Cobb scale. A short-duration electrostimulation (2 hours daily) was found to produce results similar to those obtained after overnight (9 h) electrostimulation. Moreover, the analysis of the Harrington prognostic index F confirms the positive effect of LESS in both groups of patients (2 h and 9 h of LESS).

Concurrent and Overlapping Surgery: Perspectives from Parents of Adolescents Undergoing Spinal Posterior Instrumented Fusion for Idiopathic Scoliosis.

PubMed

Bryant, Jessica; Markes, Alexander; Woolridge, Tiana; Cerruti, Dede; Dzeng, Elizabeth; Koenig, Barbara; Diab, Mohammad

2018-06-12

Prospective cross-sectional survey. To determine the perspectives of parents of patients undergoing posterior instrumented fusion for adolescent idiopathic scoliosis (AIS) regarding simultaneous surgery and trainee participation. Simultaneous ("at the same time") surgery is under scrutiny by the public, government, payers and the medical community. The objective of this study is to determine the perspectives of parents of patients undergoing posterior instrumented fusion for adolescent idiopathic scoliosis. Our goal is to inform the national conversation on this subject with real patient and family voices. A survey was prospectively administered to 31 consecutive parents of patients undergoing posterior instrumented fusion for adolescent idiopathic scoliosis at a large academic medical center. "Overlapping" was defined as simultaneity during "noncritical" parts of an operation. "Concurrent" was defined as simultaneity that includes "critical" part(s) of an operation. Participants were asked to provide levels of agreement with overlapping and concurrent surgery and anesthesia, as well as with trainee involvement. On average, respondents "strongly agree" with the need to be informed about overlapping or concurrent surgery. They "disagree" with both overlapping and concurrent scheduling, and "disagree" with trainees operating without direct supervision, even for "non-critical" parts. Informing parents about the presence of a back-up surgeon or research demonstrating safety of simultaneous surgery did not make them agreeable to simultaneous scheduling. Parents have a strong desire to be informed of simultaneous spinal surgery as part of consent on behalf of their children. Their disagreement with simultaneous surgery, as well as with trainees operating without direct supervision, suggests discordance with current guidelines and practice and should inform the national conversation moving forward. N/A.

Study on Treatment with Respect to Idiopathic Scoliosis

NASA Astrophysics Data System (ADS)

Takeuchi, Kenzen; Azegami, Hideyuki; Murachi, Shunji; Kitoh, Junzoh; Ishida, Yoshito; Kawakami, Noriaki; Makino, Mitsunori

A hypothesis that the thoracic idiopathic scoliosis is buckling phenomenon of the fourth mode induced by the growth of thoracic vertebral bodies was presented in the previous work by the authors using numerical simulations with finite element model of the spine. If the hypothesis is acceptable, sensitivity function with respect to the critical growth of thoracic vertebrae on the maximization problem of buckling load with the fourth buckling mode gives us useful information to improve and develop treatments for the idiopathic scoliosis. The numerical results analyzed by the finite element method demonstrated that the sensitivity function is high at the articular capsules of the intervertebral joints, the intervertebral disks, the costotransverse joints and the constovertebral joints around the apex of the curvature in the case of the thoracic idiopathic scoliosis.

Evaluation of spinal internal loads and lumbar curvature under holding static load at different trunk and knee positions.

PubMed

Kahrizi, Sedighe; Parnianpour, Mohammad; Firoozabadi, Seyyed Mohammad; Kasemnejad, Anoshirvan; Karimi, Elham

2007-04-01

A study was performed to investigate how different trunk and knee positions while holding static loads affect the lumbar curvature and internal loads on the lumbar spine at L4-L5. Ten healthy male subjects participated in this study. Two inclinometers were used to evaluate the curvature of lumbar spine, lordosis, while a 3D static biomechanical model was used to predict the spinal compression and shear forces at L4-L5. Eighteen static tasks while holding three level of load (0, 10 and 20 kg), two levels of knee position (45 and 180 degrees of flexion) and three levels of trunk position (neutral, 15 and 30 degree of flexion) were simulated for 10 healthy male subjects. The results of this study revealed that the lordosis of lumbar spine changed to kyphosis with increasing weight of load from 0 to 20 kg in trunk flexion position (p<0.05), but in squatting position (45 degrees knee full flexion) the higher load did not affect the curvature. The results of this study suggested, at a more flexed trunk and standing position with higher loads both external moment and internal loads increased significantly at L4-L5 level but with 45 knee flexion external moment and compression force increased and shear force decreased significantly (p < 0.05). Subjects made more effort to maintain stability of the body in squat position. The highest external moment and compression force were computed at flexed knee and trunk position with highest loads. Hence holding weight in this position must be avoided by implementing ergonomic change to the workplace.

Physical examination in adolescent idiopathic scoliosis.

PubMed

Diab, Mohammad

2007-04-01

The following distinguish the physical examination in scoliosis: it is extensive, it is revealing, and it influences treatment. Throughout this discussion, reference frequently is made to evaluation for underlying neural disease. Idiopathic scoliosis is a diagnosis of exclusion, and a neural etiology of spinal deformity must be ruled out in every case.

Influence of hamstring muscles extensibility on spinal curvatures and pelvic tilt in highly trained cyclists.

PubMed

Muyor, José M; Alacid, Fernando; López-Miñarro, Pedro A

2011-09-01

The purpose of this study was to determine the influence of hamstring muscles extensibility in standing, maximal trunk flexion with knees extended and on the bicycle in lower handlebar-hands position of highly trained cyclists. Ninety-six cyclists were recruited for the study (mean ± SD, age: 30.36 ± 5.98 years). Sagittal spinal curvatures and pelvic tilt were measured in the standing position, maximal trunk flexion with knees extended (sit-and-reach test) and while sitting on a bicycle in lower handlebar-hand position using a Spinal Mouse system. Hamstring muscles extensibility was determined in both legs by passive straight leg raise test (PSLR). The sample was divided into three groups according to PSLR angle: (1) reduced extensibility (PSLR < 80º; n = 30), (2) moderate hamstring extensibility group (PSLR = 80º - 90º; n = 35), and (3) high hamstring extensibility (PSLR = > 90º; n = 31). ANOVA analysis showed significant differences among groups for thoracic (p < 0.001) and pelvic tilt (p < 0.001) angles in the sit-and-reach test. No differences were found between groups for standing and on the bicycle position. Post hoc analysis showed significant differences in all pairwise comparisons for thoracic angle (p < 0.01) and pelvic angle (p < 0.001) in the sit-and-reach test. No differences were found in lumbar angle in any posture. In conclusion, the hamstring muscles extensibility influence the thoracic and pelvic postures when maximal trunk flexion with knees extended is performed, but not when cyclists are seated on their bicycles.

Influence of Hamstring Muscles Extensibility on Spinal Curvatures and Pelvic Tilt in Highly Trained Cyclists

PubMed Central

Muyor, José M.; Alacid, Fernando; López-Miñarro, Pedro A.

2011-01-01

The purpose of this study was to determine the influence of hamstring muscles extensibility in standing, maximal trunk flexion with knees extended and on the bicycle in lower handlebar-hands position of highly trained cyclists. Ninety-six cyclists were recruited for the study (mean ± SD, age: 30.36 ± 5.98 years). Sagittal spinal curvatures and pelvic tilt were measured in the standing position, maximal trunk flexion with knees extended (sit-and-reach test) and while sitting on a bicycle in lower handlebar-hand position using a Spinal Mouse system. Hamstring muscles extensibility was determined in both legs by passive straight leg raise test (PSLR). The sample was divided into three groups according to PSLR angle: (1) reduced extensibility (PSLR < 80º; n = 30), (2) moderate hamstring extensibility group (PSLR = 80º – 90º; n = 35), and (3) high hamstring extensibility (PSLR = > 90º; n = 31). ANOVA analysis showed significant differences among groups for thoracic (p < 0.001) and pelvic tilt (p < 0.001) angles in the sit-and-reach test. No differences were found between groups for standing and on the bicycle position. Post hoc analysis showed significant differences in all pairwise comparisons for thoracic angle (p < 0.01) and pelvic angle (p < 0.001) in the sit-and-reach test. No differences were found in lumbar angle in any posture. In conclusion, the hamstring muscles extensibility influence the thoracic and pelvic postures when maximal trunk flexion with knees extended is performed, but not when cyclists are seated on their bicycles PMID:23486997

Handedness and spinal deformity.

PubMed

Goldberg, C J; Moore, D P; Fogarty, E E; Dowling, F E

2006-01-01

Biological lateralisation is clearly manifest in scoliosis, yet its relevance is unclear. Goldberg et al. (Spine. 15(2):61-64. 1990) found an association between curve pattern and hand-preference in a screened population, but no increase in sinistrality. Milenkovic et al, (European Journal of Epidemiology, 19:969-972,2004) concluded left-handedness was a risk factor in a screened group. The database was reassessed to determine whether clinically significant scoliosis was associated with sinistrality or differed from the population norm of 10%. Patients attending the scoliosis clinic were asked their preferred writing hand. 1,636 patients were identified with complete data. Overall, left handedness occurred in 11.5%, greater than the general population (p=0.04) Left hand preference was found to be increased in boys with infantile idiopathic scoliosis and in girls with infantile, juvenile, congenital and syndromic scoliosis, but was reduced in girls with adolescent idiopathic scoliosis. Scoliosis lateralisation was random in infantile and congenital scoliosis, while left curve patterns were decreased in girls with juvenile idiopathic scoliosis and increased in boys with syndromic scoliosis. Curve pattern and handedness correlated in asymmetry in boys and girls and in girls with radiologically confirmed adolescent idiopathic scoliosis, but not in any other type. This study cannot confirm findings of left-handedness as a risk factor for spinal deformity. Its incidence is reduced in girls with adolescent idiopathic scoliosis, and the increased sinistrality in infantile scoliosis is not a new finding (Rauterberg & Tonnis Ger. Z.Orthop. 109(14):676-689. 1971). Lateralisation is undoubtedly a factor in scoliosis, but does not have a simple causal relationship, probably deriving from the underlying scoliotic process, rather than contributing to it.

Aortic Curvature Is a Predictor of Late Type Ia Endoleak and Migration After Endovascular Aneurysm Repair.

PubMed

Schuurmann, Richte C L; van Noort, Kim; Overeem, Simon P; Ouriel, Kenneth; Jordan, William D; Muhs, Bart E; 't Mannetje, Yannick; Reijnen, Michel; Fioole, Bram; Ünlü, Çağdaş; Brummel, Peter; de Vries, Jean-Paul P M

2017-06-01

To evaluate the association between aortic curvature and other preoperative anatomical characteristics and late (>1 year) type Ia endoleak and endograft migration in endovascular aneurysm repair (EVAR) patients. Eight high-volume EVAR centers contributed 116 EVAR patients (mean age 81±7 years; 103 men) to the study: 36 patients (mean age 82±7 years; 31 men) with endograft migration and/or type Ia endoleak diagnosed >1 year after the initial EVAR and 80 controls without early or late complications. Aortic curvature was calculated from the preoperative computed tomography scan as the maximum and average curvature over 5 predefined aortic segments: the entire infrarenal aortic neck, aneurysm sac, and the suprarenal, juxtarenal, and infrarenal aorta. Other morphological characteristics included neck length, neck diameter, mural neck calcification and thrombus, suprarenal and infrarenal angulation, and largest aneurysm sac diameter. Independent risk factors were identified using backward stepwise logistic regression. Relevant cutoff values for each of the variables in the final regression model were determined with the receiver operator characteristic curve. Logistic regression identified maximum curvature over the length of the aneurysm sac (>47 m -1 ; p=0.023), largest aneurysm sac diameter (>56 mm; p=0.028), and mural neck thrombus (>11° circumference; p<0.001) as independent predictors of late migration and type Ia endoleak. Aortic curvature is a predictor for late type Ia endoleak and endograft migration after EVAR. These findings suggest that aortic curvature is a better parameter than angulation to predict post-EVAR failure and should be included as a hostile neck parameter.

Three-Dimensional Spinal Morphology Can Differentiate Between Progressive and Nonprogressive Patients With Adolescent Idiopathic Scoliosis at the Initial Presentation

PubMed Central

Nault, Marie-Lyne; Mac-Thiong, Jean-Marc; Roy-Beaudry, Marjolaine; Turgeon, Isabelle; deGuise, Jacques; Labelle, Hubert

2014-01-01

Study Design. This is a prospective case-control study. Objective. The objective of this study was to compare 3-dimensional (3D) morphological parameters of the spine at the first visit between a nonprogressive (NP) and a progressive (P) group of immature adolescent idiopathic scoliosis (AIS). Summary of Background Data. Prediction of curve progression remains challenging in AIS at the first visit. Prediction of progression is based on curve type, curve magnitude, and skeletal or chronological age. Methods. A prospective cohort of 133 AIS was followed from skeletal immaturity to maturity (mean, 37 mo). The first group was made up of patients with AIS with a minimum 6-degree progression of the major curve between the first and last follow-up (P) (n = 53) and the second group was composed of patients with NP who reached maturity with less than 6-degree progression (n = 81). Computerized measurements were taken on reconstructed 3-dimensional (3D) spine radiographs of the first visit. There were 6 categories of measurements: angle of plane of maximum curvature, Cobb angles (kyphosis, lordosis), 3D wedging (apical vertebra, apical disks), rotation (upper and lower junctional vertebra, apical vertebra, and thoracolumbar junction), torsion, and slenderness (height/width ratio). t tests were also conducted. Results. There was no statistical difference between the 2 groups for age and initial Cobb angle. P presented significant hypokyphosis, and parameters related to rotation presented significant statistical differences between NP and P (plane of maximal curvature, torsion, and apical axial rotation). Depth slenderness also presented statistical differences. Conclusion. This study confirms that even at the initial visit, 3D morphological differences exist between P and NP AIS. It supports the use of 3D reconstructions of the spine in the initial evaluation of AIS to help predict outcome. Level of Evidence: 3 PMID:24776699

The role of the paravertebral muscles in adolescent idiopathic scoliosis evaluated by temporary paralysis.

PubMed

Wong, Christian; Gosvig, Kasper; Sonne-Holm, Stig

2017-01-01

Muscle imbalance has been suggested as implicated in the pathology of adolescent idiopathic scoliosis (AIS). The specific "pathomechanic" role of the paravertebral muscles as being scoliogenic (inducing scoliosis) or counteracting scoliosis in the initial development and maintenance of this spinal deformity has yet to be clarified in humans. In the present study, we investigated the radiographic changes of temporal paralysis using botulinum toxin A as localized injection therapy (ITB) in the psoas major muscle in AIS patients. Nine patients with AIS were injected one time with ITB using ultrasonic and EMG guidance in the selected spine muscles. Radiographic and clinical examinations were performed before and 6 weeks after the injection. Primary outcome parameters of radiological changes were analyzed using Wilcoxon signed-rank test and binomial test, and secondary outcome parameters of short- and long-term clinical effects were obtained. Significant radiological corrective changes were seen in the frontal plane in the thoracic and lumbar spine as well as significant derotational corrective change in the lumbar spine according to Cobb's angle measurements and to Nash and Moe's classification, respectively. No serious adverse events were detected at follow-up. In conclusion, this study demonstrated that the psoas major muscle do play a role into the pathology in adolescent idiopathic scoliosis by maintaining the curvature of the lumbar spine and thoracic spine. EudraCT number 2008-004584-19.

Comparative multifactorial analysis of the effects of idiopathic adolescent scoliosis and Scheuermann kyphosis on the self-perceived health status of adolescents treated with brace.

PubMed

Korovessis, Panagiotis; Zacharatos, Spyridon; Koureas, Georgios; Megas, Panagiotis

2007-04-01

Bracing is the most effective non-operative treatment for mild progressive spinal deformities in adolescence but it has shown a considerable impact on several aspects of adolescents' functioning. This cross-sectional study investigated the self-perceived health status of adolescents with the two most common deformities, treated with body orthosis. Seventy-nine adolescents with spinal deformities (idiopathic adolescent scoliosis, thoracic Scheuermann kyphosis) and 62 adolescents without spinal deformities were asked to complete the Quality of Life profile for Spine Deformities Instrument. This study showed that adolescents with deformities are significantly less likely to have back pain in training than controls, but more likely to have difficulty in forward bending, and in the most common daily activities while in brace. These individuals claim they wake up because of back pain and feel quite nervous with the external appearance of their body. These patients face often problems with their relations with friends, while they reported difficulties in getting up from bed and sleep at night more often than their counterparts without deformities. As they grow older, patients feel increasing ashamed of their body, as they are more concerned about the future effect of the deformity on their body. As the bracing time increases, patients have much more probability than controls to get low back pain. Girls with deformity have a higher probability than boys to get low back pain while working in the house and while training. Individuals with larger spinal curvatures have more difficulties in bending and increased incidence of back pain than their counterparts with smaller curvatures. Psychological reasons associated mainly with relations at school and back pain are the main causes for low compliance in adolescents with spinal deformities treated with body orthosis. Careful instructions for all individuals who will undergo brace therapy, psychological support for all patients

Comparative multifactorial analysis of the effects of idiopathic adolescent scoliosis and Scheuermann kyphosis on the self-perceived health status of adolescents treated with brace

PubMed Central

Zacharatos, Spyridon; Koureas, Georgios; Megas, Panagiotis

2006-01-01

Bracing is the most effective non-operative treatment for mild progressive spinal deformities in adolescence but it has shown a considerable impact on several aspects of adolescents’ functioning. This cross-sectional study investigated the self-perceived health status of adolescents with the two most common deformities, treated with body orthosis. Seventy-nine adolescents with spinal deformities (idiopathic adolescent scoliosis, thoracic Scheuermann kyphosis) and 62 adolescents without spinal deformities were asked to complete the Quality of Life profile for Spine Deformities Instrument. This study showed that adolescents with deformities are significantly less likely to have back pain in training than controls, but more likely to have difficulty in forward bending, and in the most common daily activities while in brace. These individuals claim they wake up because of back pain and feel quite nervous with the external appearance of their body. These patients face often problems with their relations with friends, while they reported difficulties in getting up from bed and sleep at night more often than their counterparts without deformities. As they grow older, patients feel increasing ashamed of their body, as they are more concerned about the future effect of the deformity on their body. As the bracing time increases, patients have much more probability than controls to get low back pain. Girls with deformity have a higher probability than boys to get low back pain while working in the house and while training. Individuals with larger spinal curvatures have more difficulties in bending and increased incidence of back pain than their counterparts with smaller curvatures. Psychological reasons associated mainly with relations at school and back pain are the main causes for low compliance in adolescents with spinal deformities treated with body orthosis. Careful instructions for all individuals who will undergo brace therapy, psychological support for all patients

Conservative management of idiopathic scoliosis--guidelines based on SOSORT 2006 Consensus.

PubMed

Kotwicki, Tomasz; Durmała, Jacek; Czaprowski, Dariusz; Głowacki, Maciej; Kołban, Maciej; Snela, Sławomir; Sliwiński, Zbigniew; Kowalski, Ireneusz M

2009-01-01

Idiopathic scoliosis, defined as a lateral curvature of the spine of above 10 degrees (Cobb angle), is seen in 2-3% of the growing age population, while curves above 20 degrees , requiring conservative treatment, are found in 0.3-0.5%. In our observation, both under-treatment of progressive curves and over-treatment of stable cases are common during conservative management of scoliosis. A model of therapeutic management is presented based on the experience of Polish clinicians specialising in the treatment of scoliosis as well as the effects of work of a panel of experts of SOSORT (Society on Scoliosis Orthopaedic and Rehabilitation Treatment). The model comprises the indications for conservative treatment according to age, curve type and size and Risser grading. The aetiology, classifications, usefulness of the Lonstein and Carlson factor of progression and other methods of determining the probability of scoliosis progression, as well as the psychological aspects of conservative management are presented. Based on the knowledge of the natural history of idiopathic scoliosis, factors of progression and on the SOSORT experts' opinion, guidelines are proposed for clinicians treating children and adolescents with idiopathic scoliosis, including the timing and course of brace treatment and the types of exercises. Uniform practical guidelines developed by experts may represent an essential step towards establishing standards of conservative scoliosis care in our country.

Effects of Exercise on Spinal Deformities and Quality of Life in Patients with Adolescent Idiopathic Scoliosis

PubMed Central

Anwer, Shahnawaz; Alghadir, Ahmad; Abu Shaphe, Md.; Anwar, Dilshad

2015-01-01

Objectives. This systematic review was conducted to examine the effects of exercise on spinal deformities and quality of life in patients with adolescent idiopathic scoliosis (AIS). Data Sources. Electronic databases, including PubMed, CINAHL, Embase, Scopus, Cochrane Register of Controlled Trials, PEDro, and Web of Science, were searched for research articles published from the earliest available dates up to May 31, 2015, using the key words “exercise,” “postural correction,” “posture,” “postural curve,” “Cobb's angle,” “quality of life,” and “spinal deformities,” combined with the Medical Subject Heading “scoliosis.” Study Selection. This systematic review was restricted to randomized and nonrandomized controlled trials on AIS published in English language. The quality of selected studies was assessed by the PEDro scale, the Cochrane Collaboration's tool, and the Grading of Recommendations Assessment, Development, and Evaluation System (GRADE). Data Extraction. Descriptive data were collected from each study. The outcome measures of interest were Cobb angle, trunk rotation, thoracic kyphosis, lumbar kyphosis, vertebral rotation, and quality of life. Data Synthesis. A total of 30 studies were assessed for eligibility. Six of the 9 selected studies reached high methodological quality on the PEDro scale. Meta-analysis revealed moderate-quality evidence that exercise interventions reduce the Cobb angle, angle of trunk rotation, thoracic kyphosis, and lumbar lordosis and low-quality evidence that exercise interventions reduce average lateral deviation. Meta-analysis revealed moderate-quality evidence that exercise interventions improve the quality of life. Conclusions. A supervised exercise program was superior to controls in reducing spinal deformities and improving the quality of life in patients with AIS. PMID:26583083

Buckling and bone modeling as factors in the development of idiopathic scoliosis.

PubMed

Goto, Manabu; Kawakami, Noriaki; Azegami, Hideyuki; Matsuyama, Yukihiro; Takeuchi, Kenzen; Sasaoka, Ryu

2003-02-15

Computational analysis using the finite-element method was used to examine a possible etiology of idiopathic scoliosis. To compare changes in the coronal and the transverse planes of idiopathic thoracic scoliosis with changes produced in a finite-element buckling model, and to investigate the influence of bone modeling on the buckling spine. Although it is now widely accepted that growth is related strongly to the onset and progression of scoliosis, the pathomechanism or etiology of idiopathic scoliosis still is not clear. A previous study showed that a buckling phenomenon caused by anterior spinal overgrowth can produce scoliosis, and that the fourth buckling mode matched the clinical characteristics associated with the thoracic type of idiopathic scoliosis. The fourth buckling mode occurs when the first, second, and third buckling modes are prevented. The spinal finite-element model used in this study consisted of 68,582 elements and 84,603 nodes. The transverse changes seen in the computed tomography images of 41 patients with idiopathic thoracic scoliosis (apex, T8; average Cobb angle, 52.5 degrees) were compared with those produced in the fourth buckling mode. Bone modeling (bone formation and resorption) was simulated as heat deformation caused by changes in temperature. The bone formation and resorption were simulated, respectively, by positive and negative volume changes in proportion to the stress that occurred in the buckling spine. Computed tomography images of scoliosis show that as the scoliosis becomes more severe, the thoracic cage decreases on the convex side of the curve and increases on the concave side. The opposite thoracic cage deformation was obtained in the fourth buckling mode. In patients with scoliosis, the sternum essentially remains in its original position with respect to the vertebrae, but in the linear buckling model, it shifted in the direction of vertebral body rotation. In contrast to clinical data, the incremental deformation

Proximal Junctional Kyphosis Following Spinal Deformity Surgery in the Pediatric Patient.

PubMed

Cho, Samuel K; Kim, Yongjung J; Lenke, Lawrence G

2015-07-01

Proper understanding and restoration of sagittal balance is critical in spinal deformity surgery, including conditions such as adolescent idiopathic scoliosis and Scheuermann kyphosis. One potential complication following spinal reconstruction is proximal junctional kyphosis. The prevalence of proximal junctional kyphosis varies in the literature, and several patient- and surgery-related risk factors have been identified. To date, the development of proximal junctional kyphosis has not been shown to lead to a negative clinical outcome following spinal fusion for adolescent idiopathic scoliosis or Scheuermann kyphosis. Treatment options range from simple observation in asymptomatic cases to revision surgery with extension of the fusion proximally. Several techniques and technologies are emerging that seek to address and prevent proximal junctional kyphosis. Copyright 2015 by the American Academy of Orthopaedic Surgeons.

Adolescents' perceptions of music therapy following spinal fusion surgery.

PubMed

Kleiber, Charmaine; Adamek, Mary S

2013-02-01

To explore adolescents' memories about music therapy after spinal fusion surgery and their recommendations for future patients. Spinal fusion for adolescent idiopathic scoliosis is one of the most painful surgeries performed. Music therapy is shown to decrease postoperative pain in children after minor surgery. In preparation for developing a preoperative information program, we interviewed adolescents who had spinal fusion and postoperative music therapy to find out what they remembered and what they recommended for future patients. Eight adolescents who had spinal fusion for adolescent idiopathic scoliosis were interviewed about their experiences. For this qualitative study, the investigators independently used thematic analysis techniques to formulate interpretive themes. Together they discussed their ideas and assigned overall meanings to the information. The eight participants were 13-17 years of age and had surgery between 2-24 months previously. The overarching themes identified from the interviews were relaxation and pain perception, choice and control, therapist interaction and preoperative information. Participants stated that music therapy helped with mental relaxation and distraction from pain. It was important to be able to choose the type of music for the therapy and to use self-control to focus on the positive. Their recommendation was that future patients should be provided with information preoperatively about music therapy and pain management. Participants recommended a combination of auditory and visual information, especially the experiences of previous patients who had spinal fusion and music therapy. Music provided live at the bedside by a music therapist was remembered vividly and positively by most of the participants. The presence of a music therapist providing patient-selected music at the bedside is important. Methods to introduce adolescents to music therapy and how to use music for relaxation should be developed and tested. © 2012

The potential role of brain asymmetry in the development of adolescent idiopathic scoliosis: a hypothesis.

PubMed

Niesluchowski, W; Dabrowska, A; Kedzior, K; Zagrajek, T

1999-10-01

The size asymmetry of cerebral hemispheres may predispose to head tilt and asymmetric blocking of the zygapophysial joints, potentially leading to the development of compensatory curvatures in the lower segments of the spine. To analyze the effects of spinal manipulation, maintained by an exercise program, on the progression of idiopathic adolescent scoliosis in 2 children aged 6 and 10. The scoliosis found was 16 and 60 degrees. For diagnosis and monitoring of therapy, we recorded qualitative parameters of shoulder asymmetry, axillary line asymmetry, and scapular angle position. Manual treatment consisted of the examinations of all sliding motion in zygapophysial joints and both sacroiliac joints and removing the limitations of the sliding motions according to the method of Karel Lewit. The treatment procedure consisted of 3 or 4 manipulations within 17 months and an exercise program. The manipulation effects were maintained by the exercise program. The exercises were done in 2 or 3 sessions weekly for a year. In both patients we observed that scoliosis decompensation was successfully stopped and the effects of the correction persisted for 10 years. Brain and head asymmetry may be only a transient state, predisposing to asymmetric blocking at the atlanto-occipital level. Removal of blocking may prevent curve progression in children who had adolescent idiopathic scoliosis. The manipulative therapy may also have a promising effect on retarding curve progression when used in skeletally immature patient.

Changes in regional activity of the psoas major and quadratus lumborum with voluntary trunk and hip tasks and different spinal curvatures in sitting.

PubMed

Park, Rachel J; Tsao, Henry; Claus, Andrew; Cresswell, Andrew G; Hodges, Paul W

2013-02-01

Cross-sectional controlled laboratory study. To investigate the function of discrete regions of psoas major (PM) and quadratus lumborum (QL) with changes in spinal curvature and hip position. Anatomically discrete regions of PM and QL may have differential function on the lumbar spine, based on anatomical and biomechanical differences in their moment arms between fascicles within each muscle. Fine-wire electrodes were inserted with ultrasound guidance into PM fascicles arising from the transverse process (PM-t) and vertebral body (PM-v) and anterior (QL-a) and posterior (QL-p) layers of QL. Recordings were made on 9 healthy participants, who performed 7 tasks with maximal voluntary efforts and adopted 3 sitting postures that involved different spinal curvatures and hip angles. Activity of PM-t was greater during trunk extension than flexion, whereas activity of PM-v was greater during hip flexion than trunk efforts. Activity of QL-p was greater during trunk extension and lateral flexion, whereas QL-a showed greater activity during lateral flexion. During sitting tasks, PM-t was more active when sitting with a short lordosis than a flat (less extended) lumbar spine posture, whereas PM-v was similarly active in both sitting postures. Activity of PM-t was more affected by changes in position of the lumbar spine than the hip, whereas PM-v was more actively involved in the movement of the hip rather than that of the lumbar spine. Moreover, from its anatomy, PM-t has a combined potential to extend/lordose the lumbar spine and flex the hip, at least in a flexed-hip position.

Fourth-generation spinal instrumentation: experience with adolescent idiopathic scoliosis at a tertiary care hospital in Pakistan

PubMed Central

Fazal, Akil; Lakdawala, Riaz H

2012-01-01

Objective To evaluate the radiological and functional outcome of surgical treatment of adolescent idiopathic scoliosis using fourth-generation posterior spinal instrumentation at The Aga Khan University, Karachi, Pakistan. Design Case series. Place and duration of study The Aga Khan University Hospital after a minimum of 2 years postoperatively. Patients and methods A total of 20 patients with adolescent idiopathic scoliosis were recruited into the study and evaluated for radiological and functional outcome. The study period was from 2000 to 2005. Radiological outcome was assessed using Cobb angle measurement pre and postoperatively, hence assessing percentage correction. The lower instrumented vertebra was taken as the neutral vertebra and the level was recorded. Functional outcome was determined using the Scoliosis Research Society patient administered questionnaire. All patients were called to the clinic and asked to fill in the form. Those patients who were out of the city were mailed the forms and requested via telephone to complete and return. Results Of the 20 patients operated on, twelve were female and eight were male. The average age at operation was 12.7 years. The mean Cobb angle was 69° preoperatively and 20° postoperatively, representing a percentage correction of 71%. The average duration of follow-up was 3.6 years. There was one major complication involving neurological injury post-op and two minor complications involving wound infection. The average Scoliosis Research Society score (on a scale of 1–5, with 5 being best) for pain was 4.5, self-image was 4.2, functional status was 4.1, mental status was 3.8, and satisfaction was 4.4. There was no relationship between the percentage correction of scoliosis and the functional outcome. Those patients with a high preoperative Cobb angle tended to have a better outcome for functional and mental status postoperatively. There was no relation between the lower instrumented vertebra and functional outcome

Fourth-generation spinal instrumentation: experience with adolescent idiopathic scoliosis at a tertiary care hospital in Pakistan.

PubMed

Fazal, Akil; Lakdawala, Riaz H

2012-01-01

To evaluate the radiological and functional outcome of surgical treatment of adolescent idiopathic scoliosis using fourth-generation posterior spinal instrumentation at The Aga Khan University, Karachi, Pakistan. Case series. The Aga Khan University Hospital after a minimum of 2 years postoperatively. A total of 20 patients with adolescent idiopathic scoliosis were recruited into the study and evaluated for radiological and functional outcome. The study period was from 2000 to 2005. Radiological outcome was assessed using Cobb angle measurement pre and postoperatively, hence assessing percentage correction. The lower instrumented vertebra was taken as the neutral vertebra and the level was recorded. Functional outcome was determined using the Scoliosis Research Society patient administered questionnaire. All patients were called to the clinic and asked to fill in the form. Those patients who were out of the city were mailed the forms and requested via telephone to complete and return. Of the 20 patients operated on, twelve were female and eight were male. The average age at operation was 12.7 years. The mean Cobb angle was 69° preoperatively and 20° postoperatively, representing a percentage correction of 71%. The average duration of follow-up was 3.6 years. There was one major complication involving neurological injury post-op and two minor complications involving wound infection. The average Scoliosis Research Society score (on a scale of 1-5, with 5 being best) for pain was 4.5, self-image was 4.2, functional status was 4.1, mental status was 3.8, and satisfaction was 4.4. There was no relationship between the percentage correction of scoliosis and the functional outcome. Those patients with a high preoperative Cobb angle tended to have a better outcome for functional and mental status postoperatively. There was no relation between the lower instrumented vertebra and functional outcome. In the correct indications, fourth-generation posterior instrumentation

Adolescent idiopathic scoliosis: Indications and efficacy of nonoperative treatment

PubMed Central

Canavese, Federico; Kaelin, André

2011-01-01

The strategy for the treatment of idiopathic scoliosis depends essentially upon the magnitude and pattern of the deformity, and its potential for progression. Treatment options include observation, bracing and/or surgery. During the past decade, several studies have demonstrated that the natural history of adolescent idiopathic scoliosis can be positively affected by nonoperative treatment, especially bracing. Other forms of conservative treatment, such as chiropractic or osteopathic manipulation, acupuncture, exercise or other manual treatments, or diet and nutrition, have not yet been proven to be effective in controlling spinal deformity progression, and those with a natural history that is favorable at the completion of growth. Observation is appropriate treatment for small curves, curves that are at low risk of progression, and those with a natural history that is favorable at the completion of growth. Indications for brace treatment are a growing child presenting with a curve of 25°–40° or a curve less than 25° with documented progression. Curves of 20°–25° in patients with pronounced skeletal immaturity should also be treated. The purpose of this review is to provide information about conservative treatment of adolescent idiopathic scoliosis. Indications for conservative treatment, hours daily wear and complications of brace treatment as well as brace types are discussed. PMID:21221217

Treatment of the idiopathic scoliosis with brace and physiotherapy.

PubMed

Hundozi-Hysenaj, Hajrije; Dallku, Iliriana Boshnjaku; Murtezani, Ardiana; Rrecaj, Shkurte

2009-01-01

Scoliosis is a three-dimensional deformation of the spine with a lateral curvature or deviation greater than 10 degrees and associated with vertebral rotation. Many conservative treatments are available for adolescents with idiopathic scoliosis, but the evidence for their effectiveness is still questioned. The objective of this study was to define the effectiveness of braces and individual physiotherapy for the comprehensive treatment of idiopathic scoliosis in adolescents. A retrospective study of 57 children with idiopathic thoracic dextroscoliosis with the magnitude of the thoracic curve between 20 degrees-35 degrees, treated in Orthopedic and Physiatrist Clinic as well as National Ortho-prosthetic Center within University Clinical Center of Kosova in Prishtina, during the period of 2003-2006. Inclusion of kinesitherapy in the comprehensive management of idiopathic scoliosis varied in the improvement of the muscle strength (satisfied and moderate) in almost 80% of the children while the correction of the curve was small in approximately 42.1% of cases. For children with idiopathic scoliosis, who require braces, an exercise program helps chest mobility, muscle strength, proper breathing flexibility in the spine, correct posture and keeps muscles in tone so that the transition period after brace removal is easier.

A Japanese Stretching Intervention Can Modify Lumbar Lordosis Curvature.

PubMed

Kadono, Norio; Tsuchiya, Kazushi; Uematsu, Azusa; Kamoshita, Hiroshi; Kiryu, Kazunori; Hortobágyi, Tibor; Suzuki, Shuji

2017-08-01

Eighteen healthy male adults were assigned to either an intervention or control group. Isogai dynamic therapy (IDT) is one of Japanese stretching interventions and has been practiced for over 70 years. However, its scientific quantitative evidence remains unestablished. The objective of this study was to determine whether IDT could modify lumbar curvature in healthy young adults compared with stretching exercises used currently in clinical practice. None of previous studies have provided data that conventional stretching interventions could modify spinal curvatures. However, this study provides the first evidence that a specific form of a Japanese stretching intervention can acutely modify the spinal curvatures. We compared the effects of IDT, a Japanese stretching intervention (n=9 males), with a conventional stretching routine (n=9 males) used widely in clinics to modify pelvic tilt and lumbar lordosis (LL) angle. We measured thoracic kyphosis (TK) and LL angles 3 times during erect standing using the Spinal Mouse before and after each intervention. IDT consisted of: (1) hip joint correction, (2) pelvic tilt correction, (3) lumbar alignment correction, and (4) squat exercise stretch. The control group performed hamstring stretches while (1) standing and (2) sitting. IDT increased LL angle to 25.1 degrees (±5.9) from 21.2 degrees (±6.9) (P=0.047) without changing TK angle (pretest: 36.8 degrees [±6.9]; posttest: 36.1 degrees [±6.5]) (P=0.572). The control group showed no changes in TK (P=0.819) and LL angles (P=0.744). IDT can thus be effective for increasing LL angle, hence anterior pelvic tilt. Such modifications could ameliorate low back pain and improve mobility in old adults with an unfavorable pelvic position.

Joint hypermobility in children with idiopathic scoliosis: SOSORT award 2011 winner

PubMed Central

2011-01-01

Background Generalized joint hypermobility (JHM) refers to increased joint mobility with simultaneous absence of any other systemic disease. JHM involves proprioception impairment, increased frequency of pain within joints and tendency to injure soft tissues while performing physical activities. Children with idiopathic scoliosis (IS) often undergo intensive physiotherapy requiring good physical capacities. Further, some physiotherapy methods apply techniques that increase joint mobility and thus may be contraindicated. The aim of this paper was to assess JHM prevalence in children with idiopathic scoliosis and to analyze the relationship between JHM prevalence and the clinical and radiological parameters of scoliosis. The methods of assessment of generalized joint hypermobility were also described. Materials and methods This case-control study included 70 subjects with IS, aged 9-18 years (mean 13.2 ± 2.2), Cobb angle range 10°-53° (mean 24.3 ± 11.7), 34 presenting single curve thoracic scoliosis and 36 double curve thoracic and lumbar scoliosis. The control group included 58 children and adolescents aged 9-18 years (mean 12.6 ± 2.1) selected at random. The presence of JHM was determined using Beighton scale complemented with the questionnaire by Hakim and Grahame. The relationship between JHM and the following variables was evaluated: curve severity, axial rotation of the apical vertebra, number of curvatures (single versus double), number of vertebrae within the curvature (long versus short curves), treatment type (physiotherapy versus bracing) and age. Statistical analysis was performed with Statistica 8.1 (StatSoft, USA). The Kolmogorov-Smirnov test, U Mann-Whitney test, Chi2 test, Pearson and Spermann correlation rank were conducted. The value p = 0.05 was adopted as the level of significance. Results JHM was diagnosed in more than half of the subjects with idiopathic scoliosis (51.4%), whilst in the control group it was diagnosed in only 19% of cases (p

Incidental occlusion of anterior spinal artery due to Onyx reflux in embolization of spinal type II arteriovenous malformation.

PubMed

Kim, Joohyun; Lee, Jang-Bo; Cho, Tai-Hyoung; Hur, Junseok W

2017-05-01

Onyx embolization is one of the standard treatments for brain arteriovenous malformations (AVMs) and is a promising method for spinal AVMs as well. Its advantages have been emphasized, and few complications have been reported with Onyx embolization in spinal AVMs. Here, we report an incidental anterior spinal artery (ASA) occlusion due to Onyx reflux during embolization of a spinal type II AVM. A 15-year-old boy presented with weakness in both upper and lower extremities. Magnetic resonance imaging and spinal angiogram revealed a spinal type II AVM with two feeders including the right vertebral artery (VA) and the right deep cervical artery. Onyx embolization was performed gradually from the VA to the deep cervical artery and an unexpected Onyx reflux to the ASA was observed during the latter stage deep cervical artery embolization. Post-operative quadriplegia and low cranial nerves (CN) dysfunction were observed. Rehabilitation treatment was performed and the patient showed marked improvement of neurologic deterioration at 1-year follow-up. Onyx is an effective treatment choice for spinal AVMs. However, due to the small vasculature of the spine compared to the brain, the nidus is rapidly packed with a small amount of Onyx, which allows Onyx reflux to unexpected vessels. Extreme caution is required and dual-lumen balloon catheter could be considered for Onyx embolization in spinal AVMs treatment.

Discrepancy in clinical versus radiological parameters describing deformity due to brace treatment for moderate idiopathic scoliosis.

PubMed

Kotwicki, Tomasz; Kinel, Edyta; Stryla, Wanda; Szulc, Andrzej

2007-12-03

The shape of the torso in patients with idiopathic scoliosis is considered to reflect the shape of the vertebral column, however the direct correlation between parameters describing clinical deformity and those characterizing radiological curvature was reported to be weak. It is not clear if the management proposed for scoliosis (physiotherapy, brace, surgery) affects equally the shape of the axial skeleton and the surface of the body. The aim of the study was to compare clinical deformity of (1) idiopathic scoliosis girls being under brace treatment for radiological curves of 25 to 40 degrees and (2) non treated scoliotic girls matched for age and Cobb angle. Cross-sectional study of 24 girls wearing the brace versus 26 girls without brace treatment, matched for age and Cobb angle. Patients wearing the brace for more than 6 months, when comparing to patients without brace, may present different external morphology of the trunk, in spite of having similar Cobb angle. Material. girls, idiopathic scoliosis, growing age (10-16 years), Cobb angle minimum 25 degrees , maximum 40 degrees . The braced group consisted of girls wearing a TLSO brace (Cheneau) for more than 6 months with minimum of 16 hours per day. The non-braced group consisted of girls first seen for their spinal deformity, previously not treated. The groups presented similar curve pattern. Methods. Scoliometer exam: angle of trunk rotation at three levels of the spine: upper thoracic, main thoracic, lumbar or thoracolumbar. The maximal angle was noted at each level and the sum of three levels was calculated. Posterior trunk symmetry index (POTSI) and Hump Sum were measured using surface topography. Cobb angle was 34.9 degrees +/- 4.8 degrees in braced and 32.7 degrees +/- 4.9 degrees in un-braced patients (difference not significant). The age was 14.1 +/- 1.6 years in braced patients and 13.1 +/- 1.9 years in un-braced group (p = 0.046). The value of angle of trunk rotation in the main curvature was 8

Back Pain Prevalence Is Associated With Curve-type and Severity in Adolescents With Idiopathic Scoliosis: A Cross-sectional Study.

PubMed

Théroux, Jean; Le May, Sylvie; Hebert, Jeffrey J; Labelle, Hubert

2017-08-01

A cross-sectional study. The aim of this study was to investigate spinal pain prevalence in adolescents with idiopathic scoliosis (AIS) and to explore associations between pain intensity and pain-related disability with scoliosis site, severity, and spinal bracing. The causal link between spinal pain and AIS remains unclear. Spinal asymmetry has been recognized as a back pain risk factor, which is a known cause of care-seeking in adolescents. Participants were recruited from an outpatient tertiary-care scoliosis clinic. Pain intensity and pain-related disability were measured by the Brief Pain Inventory questionnaire and the Roland-Morris Disability Questionnaire. Scoliosis severity estimation was performed using Cobb angles. Associations were explored using multiple linear regressions and reported with unstandardized beta coefficients (β) adjusted for age and sex. We recruited 500 patients (85% female) with mean (SD) age of 14.2 (1.8) years. Means (SD) of thoracic and lumbar Cobb angle were 24.54(9.77) and 24.13 (12.40), respectively. Spinal pain prevalence was 68% [95% confidence interval (95% CI): 64.5-72.4] with a mean intensity of 1.63 (SD, 1.89). Spinal pain intensity was positively associated with scoliosis severity in the main thoracic (P = 0.003) and lumbar (P = 0.001) regions. The mean (SD) disability score was 1.73 (2.98). Disability was positively associated with scoliosis severity in the proximal thoracic (P = 0.035), main thoracic (P = 0.000), and lumbar (P = 0.000) regions.Spinal bracing was associated with lower spinal pain intensity in the thoracic (P = 0.000) and lumbar regions (P = 0.009). Bracing was also related with lower disability for all spinal areas (P < 0.045). Spinal pain is common among patients with AIS, and greater spinal deformity was associated with higher pain intensity. These findings should inform clinical decision-making when caring for patients with AIS. 3.

Minimally invasive scoliosis surgery assisted by O-arm navigation for Lenke Type 5C adolescent idiopathic scoliosis: a comparison with standard open approach spinal instrumentation.

PubMed

Zhu, Weiguo; Sun, Weixiang; Xu, Leilei; Sun, Xu; Liu, Zhen; Qiu, Yong; Zhu, Zezhang

2017-04-01

OBJECTIVE Recently, minimally invasive scoliosis surgery (MISS) was introduced for the correction of adult scoliosis. Multiple benefits including a good deformity correction rate and fewer complications have been demonstrated. However, few studies have reported on the use of MISS for the management of adolescent idiopathic scoliosis (AIS). The purpose of this study was to investigate the outcome of posterior MISS assisted by O-arm navigation for the correction of Lenke Type 5C AIS. METHODS The authors searched a database for all patients with AIS who had been treated with either MISS or PSF between November 2012 and January 2014. Levels of fusion, density of implants, operation time, and estimated blood loss (EBL) were recorded. Coronal and sagittal parameters were evaluated before surgery, immediately after surgery, and at the last follow-up. The accuracy of pedicle screw placement was assessed according to postoperative axial CT images in both groups. The 22-item Scoliosis Research Society questionnaire (SRS-22) results and complications were collected during follow-up. RESULTS The authors retrospectively reviewed the records of 45 patients with Lenke Type 5C AIS, 15 who underwent posterior MISS under O-arm navigation and 30 who underwent posterior spinal fusion (PSF). The 2 treatment groups were matched in terms of baseline characteristics. Comparison of radiographic parameters revealed no obvious difference between the 2 groups immediately after surgery or at the final follow-up; however, the MISS patients had significantly less EBL (p < 0.001) and longer operation times (p = 0.002). The evaluation of pain and self-image using the SRS-22 showed significantly higher scores in the MISS group (p = 0.013 and 0.046, respectively) than in the PSF group. Postoperative CT showed high accuracy in pedicle placement in both groups. No deep wound infection, pseudarthrosis, additional surgery, implant failure, or neurological complications were recorded in either group

Spinal Health during Unloading and Reloading Associated with Spaceflight.

PubMed

Green, David A; Scott, Jonathan P R

2017-01-01

Spinal elongation and back pain are recognized effects of exposure to microgravity, however, spinal health has received relatively little attention. This changed with the report of an increased risk of post-flight intervertebral disc (IVD) herniation and subsequent identification of spinal pathophysiology in some astronauts post-flight. Ground-based analogs, particularly bed rest, suggest that a loss of spinal curvature and IVD swelling may be factors contributing to unloading-induced spinal elongation. In flight, trunk muscle atrophy, in particular multifidus , may precipitate lumbar curvature loss and reduced spinal stability, but in-flight (ultrasound) and pre- and post-flight (MRI) imaging have yet to detect significant IVD changes. Current International Space Station missions involve short periods of moderate-to-high spinal (axial) loading during running and resistance exercise, superimposed upon a background of prolonged unloading (microgravity). Axial loading acting on a dysfunctional spine, weakened by anatomical changes and local muscle atrophy, might increase the risk of damage/injury. Alternatively, regular loading may be beneficial. Spinal pathology has been identified in-flight, but there are few contemporary reports of in-flight back injury and no recent studies of post-flight back injury incidence. Accurate routine in-flight stature measurements, in- and post-flight imaging, and tracking of pain and injury (herniation) for at least 2 years post-flight is thus warranted. These should be complemented by ground-based studies, in particular hyper buoyancy floatation (HBF) a novel analog of spinal unloading, in order to elucidate the mechanisms and risk of spinal injury, and to evaluate countermeasures for exploration where injury could be mission critical.

Idiopathic and normal lateral lumbar curves: muscle effects interpreted by 12th rib length asymmetry with pathomechanic implications for lumbar idiopathic scoliosis.

PubMed

Grivas, Theodoros B; Burwell, R Geoffrey; Kechagias, Vasileios; Mazioti, Christina; Fountas, Apostolos; Kolovou, Dimitra; Christodoulou, Evangelos

2016-01-01

The historical view of scoliosis as a primary rotation deformity led to debate about the pathomechanic role of paravertebral muscles; particularly multifidus, thought by some to be scoliogenic, counteracting, uncertain, or unimportant. Here, we address lateral lumbar curves (LLC) and suggest a pathomechanic role for quadrates lumborum, (QL) in the light of a new finding, namely of 12th rib bilateral length asymmetry associated with idiopathic and small non-scoliosis LLC. Group 1: The postero-anterior spinal radiographs of 14 children (girls 9, boys 5) aged 9-18, median age 13 years, with right lumbar idiopathic scoliosis (IS) and right LLC less that 10°, were studied. The mean Cobb angle was 12° (range 5-22°). Group 2: In 28 children (girls 17, boys 11) with straight spines, postero-anterior spinal radiographs were evaluated similarly to the children with the LLC, aged 8-17, median age 13 years. The ratio of the right/left 12th rib lengths and it's reliability was calculated. The difference of the ratio between the two groups was tested; and the correlation between the ratio and the Cobb angle estimated. Statistical analysis was done using the SPSS package. The ratio's reliability study showed intra-observer +/-0,036 and the inter-observer error +/-0,042 respectively in terms of 95 % confidence limit of the error of measurements. The 12th rib was longer on the side of the curve convexity in 12 children with LLC and equal in two patients with lumbar scoliosis. The 12th rib ratios of the children with lumbar curve were statistically significantly greater than in those with straight spines. The correlation of the 12th rib ratio with Cobb angle was statistically significant. The 12th thoracic vertebrae show no axial rotation (or minimal) in the LLC and no rotation in the straight spine group. It is not possible, at present, to determine whether the 12th convex rib lengthening is congenitally lengthened, induced mechanically, or both. Several small muscles are

Inter- and intratester reliability values of ultrasound imaging measurements of diaphragm movement in the thoracic and thoracolumbar curves in adolescent idiopathic scoliosis.

PubMed

Noh, Dong Koog; Koh, Jae-Hyun; You, Joshua Sung-H

2016-01-01

The purpose of this study was to determine intertester and intratester reliability of ultrasound measurements of bilateral diaphragm excursions in the thoracic and thoracolumbar spinal curves of 31 females with adolescent idiopathic scoliosis (AIS) (mean age = 14.1 ± 1.8 years). Subjects were tested during tidal breathing using real-time ultrasound imaging with a 3.5 MHz curvilinear transducer. There were no significant differences in intratester and intertester reliability values in bilateral diaphragmatic excursions measured at the thoracolumbar spinal curve, whereas significant differences were observed in measurements taken at the thoracic spinal curve (p < 0.05). Overall, the intertester and intratester reliabilities of the thoracic and thoracolumbar curves in AIS ranged from 0.764 to 0.998. These findings suggest that ultrasound imaging is highly reliable between and within testers and is useful to precisely discriminate pathological diaphragm movement in idiopathic thoracic scoliosis and idiopathic thoracolumbar scoliosis.

Role of facet curvature for accurate vertebral facet load analysis.

PubMed

Holzapfel, Gerhard A; Stadler, Michael

2006-06-01

The curvature of vertebral facet joints may play an important role in the study of load-bearing characteristics and clinical interventions such as graded facetectomy. In previously-published finite element simulations of this procedure, the curvature was either neglected or approximated with a varying degree of accuracy. Here we study the effect of the curvature in three different load situations by using a numerical model which is able to represent the actual curvature without any loss of accuracy. The results show that previously-used approximations of the curvature lead to good results in the analysis of sagittal moment/rotation. However, for sagittal shear-force/displacement and for the contact stress distribution, previous results deviate significantly from our results. These findings are supported through related convergence studies. Hence we can conclude that in order to obtain reliable results for the analysis of sagittal shear-force/displacement and the contact stress distribution in the facet joint, the curvature must not be neglected. This is of particular importance for the numerical simulation of the spine, which may lead to improved diagnostics, effective surgical planning and intervention. The proposed method may represent a more reliable basis for optimizing the biomedical engineering design for tissue engineering or, for example, for spinal implants.

Geometric Structure of 3D Spinal Curves: Plane Regions and Connecting Zones

PubMed Central

Berthonnaud, E.; Hilmi, R.; Dimnet, J.

2012-01-01

This paper presents a new study of the geometric structure of 3D spinal curves. The spine is considered as an heterogeneous beam, compound of vertebrae and intervertebral discs. The spine is modeled as a deformable wire along which vertebrae are beads rotating about the wire. 3D spinal curves are compound of plane regions connected together by zones of transition. The 3D spinal curve is uniquely flexed along the plane regions. The angular offsets between adjacent regions are concentrated at level of the middle zones of transition, so illustrating the heterogeneity of the spinal geometric structure. The plane regions along the 3D spinal curve must satisfy two criteria: (i) a criterion of minimum distance between the curve and the regional plane and (ii) a criterion controlling that the curve is continuously plane at the level of the region. The geometric structure of each 3D spinal curve is characterized by the sizes and orientations of regional planes, by the parameters representing flexed regions and by the sizes and functions of zones of transition. Spinal curves of asymptomatic subjects show three plane regions corresponding to spinal curvatures: lumbar, thoracic and cervical curvatures. In some scoliotic spines, four plane regions may be detected. PMID:25031873

Spinal Health during Unloading and Reloading Associated with Spaceflight

PubMed Central

Green, David A.; Scott, Jonathan P. R.

2018-01-01

Spinal elongation and back pain are recognized effects of exposure to microgravity, however, spinal health has received relatively little attention. This changed with the report of an increased risk of post-flight intervertebral disc (IVD) herniation and subsequent identification of spinal pathophysiology in some astronauts post-flight. Ground-based analogs, particularly bed rest, suggest that a loss of spinal curvature and IVD swelling may be factors contributing to unloading-induced spinal elongation. In flight, trunk muscle atrophy, in particular multifidus, may precipitate lumbar curvature loss and reduced spinal stability, but in-flight (ultrasound) and pre- and post-flight (MRI) imaging have yet to detect significant IVD changes. Current International Space Station missions involve short periods of moderate-to-high spinal (axial) loading during running and resistance exercise, superimposed upon a background of prolonged unloading (microgravity). Axial loading acting on a dysfunctional spine, weakened by anatomical changes and local muscle atrophy, might increase the risk of damage/injury. Alternatively, regular loading may be beneficial. Spinal pathology has been identified in-flight, but there are few contemporary reports of in-flight back injury and no recent studies of post-flight back injury incidence. Accurate routine in-flight stature measurements, in- and post-flight imaging, and tracking of pain and injury (herniation) for at least 2 years post-flight is thus warranted. These should be complemented by ground-based studies, in particular hyper buoyancy floatation (HBF) a novel analog of spinal unloading, in order to elucidate the mechanisms and risk of spinal injury, and to evaluate countermeasures for exploration where injury could be mission critical. PMID:29403389

Global geometric torsion estimation in adolescent idiopathic scoliosis.

PubMed

Kadoury, Samuel; Shen, Jesse; Parent, Stefan

2014-04-01

Several attempts have been made to measure geometrical torsion in adolescent idiopathic scoliosis (AIS) and quantify the three-dimensional (3D) deformation of the spine. However, these approaches are sensitive to imprecisions in the 3D modeling of the anatomy and can only capture the effect locally at the vertebrae, ignoring the global effect at the regional level and thus have never been widely used to follow the progression of a deformity. The goal of this work was to evaluate the relevance of a novel geometric torsion descriptor based on a parametric modeling of the spinal curve as a 3D index of scoliosis. First, an image-based approach anchored on prior statistical distributions is used to reconstruct the spine in 3D from biplanar X-rays. Geometric torsion measuring the twisting effect of the spine is then estimated using a technique that approximates local arc-lengths with parametric curve fitting centered at the neutral vertebra in different spinal regions. We first evaluated the method with simulated experiments, demonstrating the method's robustness toward added noise and reconstruction inaccuracies. A pilot study involving 65 scoliotic patients exhibiting different types of deformities was also conducted. Results show the method is able to discriminate between different types of deformation based on this novel 3D index evaluated in the main thoracic and thoracolumbar/lumbar regions. This demonstrates that geometric torsion modeled by parametric spinal curve fitting is a robust tool that can be used to quantify the 3D deformation of AIS and possibly exploited as an index to classify the 3D shape.

Eliminating the use of allogeneic blood products in adolescent idiopathic scoliosis surgery.

PubMed

Berney, Mark J; Dawson, Peter H; Phillips, Margaret; Lui, Darren F; Connolly, Paul

2015-07-01

The aim of this study was to compare transfusion requirements in patients before and after the introduction of tranexamic acid as standard in patients undergoing spinal surgery for idiopathic scoliosis in a national orthopaedic hospital. A retrospective chart review of 56 idiopathic scoliosis patients who underwent posterior spinal instrumentation and fusion between 2009 and 2013 at our institution. Preoperative, intraoperative, and postoperative data were measured. Patients who received tranexamic acid as standard (n = 31) showed a trend towards a decrease in transfusion requirements compared with those who received no tranexamic acid (n = 25). These patients had a statistically significant decrease in operative time (223 vs 188 min, p = 0.005), and estimated intraoperative blood loss was reduced by nearly 50% in the tranexamic acid group. They also had an associated reduced decrease in haemoglobin between preoperative and postoperative levels (4 vs 5 g/dL, p = 0.01). Since February 2012, no patient has required intraoperative or postoperative allogeneic blood product transfusion in this hospital. The routine use of antifibrinolytic medications in patients undergoing surgery for adolescent idiopathic scoliosis has effectively eliminated the need for allogeneic blood products.

Ascending aortic curvature as an independent risk factor for type A dissection, and ascending aortic aneurysm formation: a mathematical model.

PubMed

Poullis, Michael P; Warwick, Richard; Oo, Aung; Poole, Robert J

2008-06-01

To develop a mathematical model to demonstrate that ascending aortic curvature is an independent risk factor for type A dissections, in addition to hypertension, bicuspid aortic valve, aneurysm of ascending aorta, and intrinsic aortic tissue abnormalities, like Marfan's syndrome. A steady state one-dimensional flow analysis was performed, utilising Newton's third law of motion. Five different clinical scenarios were evaluated: (1) effect of aortic curvature; (2) effect of beta-blockers, (3) effect of patient size, (4) forces on a Marfan's aorta, and (5) site of entry flap in aortic dissection. Aortic curvature increases the forces exerted on the ascending aorta by a factor of over 10-fold. Aortic curvature can cause patients with a systolic blood pressure of 8 0mmHg to have greater forces exerted on their aorta despite smaller diameters and lower cardiac outputs, than patients with systolic blood pressures of 120 mmHg. In normal diameter aortas, beta-blockers have minimal effect compared with aortic curvature. Aortic curvature may help to explain why normal diameter aortas can dissect, and also that the point of the entry tear may be potentially predictable. Aortic curvature has major effects on the forces exerted on the aorta in patients with Marfan's syndrome. Aortic curvature is relatively more important that aortic diameter, blood pressure, cardiac output, beta-blocker use, and patient size with regard to the force acting on the aortic wall. This may explain why some patients with normal diameter ascending aortas with or without Marfan's syndrome develop type A dissections and aneurysms. Aortic curvature may also help to explain the site of entry tear in acute type A dissection. Further clinical study is needed to validate this study's finding.

Validation, repeatability and reproducibility of a noninvasive instrument for measuring thoracic and lumbar curvature of the spine in the sagittal plane.

PubMed

Chaise, Fabiana O; Candotti, Cláudia T; Torre, Marcelo L; Furlanetto, Tássia S; Pelinson, Patricia P T; Loss, Jefferson F

2011-01-01

The need for early identification of postural abnormalities without exposing patients to constant radiation has stimulated the development of instruments aiming to measure the spinal curvatures. To verify the validity, repeatability and reproducibility of angular measures of sagittal curvatures of the spine obtained using an adapted arcometer, by comparing them with Cobb angles of the respective curvatures obtained by using X-rays. 52 participants were submitted to two procedures designed to evaluate the thoracic and lumbar curvatures: (1) X-ray examination from which the Cobb angles (CA) of both curvatures were obtained, and (2) measuring the angles with the arcometer (AA). Two evaluators collected the data using the arcometer, with the rods placed at T1, T12, L1 and L5 spinous processes levels in a way as to permit linear measurements which, with aid of trigonometry, supplied the AA. There was a very strong and significant correlation between AA and CA (r=0.94; p<0.01), with no-significant difference (p=0.32), for the thoracic curvature. There was a strong and significant correlation for the lumbar curvature (r=0.71; p<0.01) between AA and CA, with no-significant difference (p=0.30). There is a very strong correlation between intra-evaluator and inter-evaluator AA. It was possible to quantify reliably the thoracic and lumbar curvatures with the arcometer and it can thus be considered valid and reliable and for use in evaluating spinal curvatures in the sagittal plane.

Spinning particles in vacuum spacetimes of different curvature types

NASA Astrophysics Data System (ADS)

Semerák, O.; Šrámek, M.

2015-09-01

We consider the motion of spinning test particles with nonzero rest mass in the "pole-dipole" approximation, as described by the Mathisson-Papapetrou-Dixon (MPD) equations, and examine its properties in dependence on the spin supplementary condition added to close the system. In order to better understand the spin-curvature interaction, the MPD equation of motion is decomposed in the orthonormal tetrad whose time vector is given by the four-velocity Vμ chosen to fix the spin condition (the "reference observer") and the first spatial vector by the corresponding spin sμ; such projections do not contain the Weyl scalars Ψ0 and Ψ4 obtained in the associated Newman-Penrose (NP) null tetrad. One natural option of how to choose the remaining two spatial basis vectors is shown to follow "intrinsically" whenever Vμ has been chosen; it is realizable if the particle's four-velocity and four-momentum are not parallel. In order to see how the problem depends on the algebraic type of curvature, one first identifies the first vector of the NP tetrad kμ with the highest-multiplicity principal null direction of the Weyl tensor, and then sets Vμ so that kμ belong to the spin-bivector eigenplane. In spacetimes of any algebraic type but III, it is known to be possible to rotate the tetrads so as to become "transverse," namely so that Ψ1 and Ψ3 vanish. If the spin-bivector eigenplane could be made to coincide with the real-vector plane of any of such transverse frames, the spinning particle motion would consequently be fully determined by Ψ2 and the cosmological constant; however, this can be managed in exceptional cases only. Besides focusing on specific Petrov types, we derive several sets of useful relations that are valid generally and check whether/how the exercise simplifies for some specific types of motion. The particular option of having four-velocity parallel to four-momentum is advocated, and a natural resolution of nonuniqueness of the corresponding reference

Intensive care unit versus hospital floor: a comparative study of postoperative management of patients with adolescent idiopathic scoliosis.

PubMed

Shan, Le-Qun; Skaggs, David L; Lee, Christopher; Kissinger, Catherine; Myung, Karen S

2013-04-03

Patients undergoing posterior spinal instrumentation and fusion surgery for adolescent idiopathic scoliosis were admitted to the intensive care unit until two years ago, at which time we changed our protocol to admit these patients to the general hospital floor following a brief stay in a postanesthesia care unit. This study compared postoperative management on a hospital floor with that in the intensive care unit for patients with adolescent idiopathic scoliosis undergoing posterior spinal fusion. A retrospective review of 124 consecutive patients with adolescent idiopathic scoliosis treated with spinal fusion from August 2007 to August 2010 was performed. Inclusion criteria were a diagnosis of adolescent idiopathic scoliosis and posterior spinal instrumentation and fusion surgery. Of 124 patients, sixty-six were managed postoperatively in the intensive care unit and fifty-eight, on the hospital floor. The mean age at the time of surgery was fourteen years. A mean of eleven vertebral levels (range, six to fifteen levels) were fused. No significant difference between the groups was found with respect to the mean age at the time of surgery, mean weight, mean preoperative and postoperative Cobb angles, and mean number of levels fused (p ≥ 0.12). However, the use of analgesic and antianxiety medication, number of postoperative blood tests, days of hospital stay, and number of physical therapy sessions were significantly decreased in the floor group compared with the intensive care unit group (p ≤ 0.05). No patient from the floor group had to be admitted to the intensive care unit. The mean charge was $33,121 for the floor group and $39,252 for the intensive care unit group (p < 0.001). Initial postoperative management of patients with adolescent idiopathic scoliosis following a posterior spinal instrumentation and fusion surgery on a general hospital floor, rather than in an intensive care unit, was associated with a shorter hospital stay, fewer blood tests, less

Measurement of sternal curvature angle on patients with pectus excavatum.

PubMed

Lee, Cory; Zavala-Garcia, Abraham; Teekappanavar, Neha; Lee, Catherine; Idowu, Olajire; Kim, Sunghoon

2017-01-01

Pectus excavatum (PE) is a chest deformity characterized by marked sternal depression. The objective of this study was to quantify the sternal curvature observed in patients diagnosed with PE using the sternal curvature angle (SCA). A retrospective review of lateral chest X-rays of patients with PE from 2006 to 2013 was performed. The SCA was measured in a manner similar to the method of Cobb's angle is used to measure spinal curvature. SCA and Haller index were calculated from the chest X-rays for all patients. Lateral chest X-rays of 202 PE and 196 normal control patients were analyzed. The mean SCA ± SD of PE patients was 40.56° ± 12.88° compared to 22.02° ± 7.65° for normal patients. The difference was statistically significant with a p value of <0.0001. No significant concordance between SCA and Haller index measurements in the PE group was found (Kendall τ = -0.00015, p value = 0.9975). The difference in sternal curvature as measured by the sternal curvature angle between the pectus excavatum and normal patients was statistically significant. Our data suggest that sternal depression evident in PE patients is not a simple linear depression of the sternum but due to curvature in the sternal body.

Idiopathic hypersomnia.

PubMed

Billiard, Michel; Sonka, Karel

2016-10-01

Idiopathic hypersomnia continues to evolve from the concept of "sleep drunkenness" introduced by Bedrich Roth in Prague in 1956 and the description of idiopathic hypersomnia with two forms, polysymptomatic and monosymptomatic, by the same Bedrich Roth in 1976. The diagnostic criteria of idiopathic hypersomnia have varied with the successive revisions of the International classifications of sleep disorders, including the recent 3rd edition. No epidemiological studies have been conducted so far. Disease onset occurs most often during adolescence or young adulthood. A familial background is often present but rigorous studies are still lacking. The key manifestation is hypersomnolence. It is often accompanied by sleep of long duration and debilitating sleep inertia. Polysomnography (PSG) followed by a multiple sleep latency test (MSLT) is mandatory, as well as a 24 h PSG or a 2-wk actigraphy in association with a sleep log to ensure a total 24-h sleep time longer than or equal to 66O minutes, when the mean sleep latency on the MSLT is longer than 8 min. Yet, MSLT is neither sensitive nor specific and the polysomnographic diagnostic criteria require continuous readjustment and biologic markers are still lacking. Idiopathic hypersomnia is most often a chronic condition though spontaneous remission may occur. The condition is disabling, sometimes even more so than narcolepsy type 1 or 2. Based on neurochemical, genetic and immunological analyses as well as on exploration of the homeostatic and circadian processes of sleep, various pathophysiological hypotheses have been proposed. Differential diagnosis involves a number of diseases and it is not yet clear whether idiopathic hypersomnia and narcolepsy type 2 are not the same condition. Until now, the treatment of idiopathic hypersomnia has mirrored that of the sleepiness of narcolepsy type 1 or 2. The first randomized, double-blind, placebo-controlled trials of modafinil have just been published, as well as a double

Predicting Postsurgical Satisfaction in Adolescents With Idiopathic Scoliosis: The Role of Presurgical Functioning and Expectations.

PubMed

Sieberg, Christine B; Manganella, Juliana; Manalo, Gem; Simons, Laura E; Hresko, M Timothy

2017-12-01

There is a need to better assess patient satisfaction and surgical outcomes. The purpose of the current study is to identify how preoperative expectations can impact postsurgical satisfaction among youth with adolescent idiopathic scoliosis undergoing spinal fusion surgery. The present study includes patients with adolescent idiopathic scoliosis undergoing spinal fusion surgery enrolled in a prospective, multicentered registry examining postsurgical outcomes. The Scoliosis Research Society Questionnaire-Version 30, which assesses pain, self-image, mental health, and satisfaction with management, along with the Spinal Appearance Questionnaire, which measures surgical expectations was administered to 190 patients before surgery and 1 and 2 years postoperatively. Regression analyses with bootstrapping (with n=5000 bootstrap samples) were conducted with 99% bias-corrected confidence intervals to examine the extent to which preoperative expectations for spinal appearance mediated the relationship between presurgical mental health and pain and 2-year postsurgical satisfaction. Results indicate that preoperative mental health, pain, and expectations are predictive of postsurgical satisfaction. With the shifting health care system, physicians may want to consider patient mental health, pain, and expectations before surgery to optimize satisfaction and ultimately improve clinical care and patient outcomes. Level I-prognostic study.

Detection of progressive idiopathic scoliosis during growth using back surface topography: a prospective study of 100 patients.

PubMed

De Korvin, G; Randriaminahisoa, T; Cugy, E; Cheze, L; de Sèze, M

2014-12-01

The progression of adolescent idiopathic scoliosis is typically monitored via regular radiographic follow-up. The Cobb angle (as measured on whole-spine radiographs) is considered as the gold standard in scoliosis monitoring. To determine the sensitivity and specificity of back surface topography parameters, with a view to detecting changes in the Cobb angle. One hundred patients (mean age: 13.3) with Cobb angles greater than 10 degrees were included. Topographic parameters were measured in a standard position and in a position with hunched shoulders. Gibbosities and spinal curvatures were evaluated. An increase of more than 2 degrees in any one gibbosity or in the sum of the gibbosities (in either of the two examination positions) enabled the detection of a five-degree increase in the Cobb angle with a sensitivity of 86% and a specificity of 50%. If the present results are confirmed by other studies, analysis with back surface topography parameters may reduce the number of X-ray examinations required to detect increases in the Cobb angle. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Assessment of scoliosis by direct measurement of the curvature of the spine

NASA Astrophysics Data System (ADS)

Dougherty, Geoff; Johnson, Michael J.

2009-02-01

We present two novel metrics for assessing scoliosis, in which the geometric centers of all the affected vertebrae in an antero-posterior (A-P) radiographic image are used. This is in contradistinction to the existing methods of using selected vertebrae, and determining either their endplates or the intersections of their diagonals, to define a scoliotic angle. Our first metric delivers a scoliotic angle, comparable to the Cobb and Ferguson angles. It measures the sum of the angles between the centers of the affected vertebrae, and avoids the need for an observer to decide on the extent of component curvatures. Our second metric calculates the normalized root-mean-square curvature of the smoothest path comprising piece-wise polynomial splines fitted to the geometric centers of the vertebrae. The smoothest path is useful in modeling the spinal curvature. Our metrics were compared to existing methods using radiographs from a group of twenty subjects with spinal curvatures of varying severity. Their values were strongly correlated with those of the scoliotic angles (r = 0.850 - 0.886), indicating that they are valid surrogates for measuring the severity of scoliosis. Our direct use of positional data removes the vagaries of determining variably shaped endplates, and circumvented the significant interand intra-observer errors of the Cobb and Ferguson methods. Although we applied our metrics to two-dimensional (2- D) data in this paper, they are equally applicable to three-dimensional (3-D) data. We anticipate that they will prove to be the basis for a reliable 3-D measurement and classification system.

[Therapeutic algorithm of idiopathic scoliosis in children].

PubMed

Ciortan, Ionica; Goţia, D G

2008-01-01

Acquired deformations of spinal cord (scoliosis, kyphosis, lordosis) represent a frequent pathology in child; their treatment is complex, with variable results which depend on various parameters. Mild scoliosis, with an angle less than 30 degrees, is treated with physiotherapy and regular follow-up. If the angle is higher than 30 degrees, the orthopedic corset is required; the angle over 45 degrees impose surgically correction. The indications of every therapeutic method depend on many factors, the main target of the treatment is to prevent the aggravation of the curvature; concerning the surgery, the goal is to obtain a correction as normal as possible of the spinal axis.

The association of patient characteristics and spinal curve parameters with Lenke classification types.

PubMed

Sponseller, Paul D; Flynn, John M; Newton, Peter O; Marks, Michelle C; Bastrom, Tracey P; Petcharaporn, Maty; McElroy, Mark J; Lonner, Baron S; Betz, Randal R

2012-06-01

Retrospective review. To determine the association of patient characteristics and spinal curve parameters with Lenke curve types. The Lenke curve classification may be used for surgical planning and clinical research. We retrospectively reviewed the records of 1912 patients with adolescent idiopathic scoliosis who underwent initial surgery at 21 years of age or younger; collected data on patient's age, patient's sex, primary curve magnitude (<50°, 50°-75°, and .75°), and Scoliosis Research Society (SRS) outcomes questionnaire (SRS-22) score; and compared that data by Lenke curve type. Analysis of variance and χ tests were used as appropriate (significance level, P ≤ 0.005). RESULTS.: Lenke types vary by sex: male patients had more major thoracic (types 1-4) than major thoracolumbar/lumbar (types 5 and 6) curves, fewer lumbar C-modifiers (32% vs. 44%), and less apical lumbar translation (1.1 vs. 1.7 cm). Lenke types vary by frequency: the most common type was 1 (50%); the least common, 4 (4%). Lenke types vary by magnitude: type 4 had the greatest percentage of large curves (52% of curves .75°), most smaller curves were types 1 and 5, and type 4 had the largest mean magnitude (78° ± 17°). Lenke types vary by patient age: type 5 curves occurred in the oldest patients (average age at surgery: 15.4 ± 2.2 vs. 14.3 ± 14.6 years for all others) despite having the lowest mean magnitude (P = 0.001); curve size was negatively correlated with age at surgery (r = -0.16, P = 0.001). Lenke types vary by patient self-image: patients with type 4 curves had lower preoperative SRS outcome scores for self-image than did patients with type 1 curves (P = 0.005). Lenke types vary by sex, frequency magnitude, patient age, and patient self-image, which should be considered in designing studies.

Discrepancy in clinical versus radiological parameters describing deformity due to brace treatment for moderate idiopathic scoliosis

PubMed Central

Kotwicki, Tomasz; Kinel, Edyta; Stryla, Wanda; Szulc, Andrzej

2007-01-01

Background The shape of the torso in patients with idiopathic scoliosis is considered to reflect the shape of the vertebral column, however the direct correlation between parameters describing clinical deformity and those characterizing radiological curvature was reported to be weak. It is not clear if the management proposed for scoliosis (physiotherapy, brace, surgery) affects equally the shape of the axial skeleton and the surface of the body. The aim of the study was to compare clinical deformity of (1) idiopathic scoliosis girls being under brace treatment for radiological curves of 25 to 40 degrees and (2) non treated scoliotic girls matched for age and Cobb angle. Methods Cross-sectional study of 24 girls wearing the brace versus 26 girls without brace treatment, matched for age and Cobb angle. Hypothesis: Patients wearing the brace for more than 6 months, when comparing to patients without brace, may present different external morphology of the trunk, in spite of having similar Cobb angle. Material. Inclusion criteria: girls, idiopathic scoliosis, growing age (10–16 years), Cobb angle minimum 25°, maximum 40°. The braced group consisted of girls wearing a TLSO brace (Cheneau) for more than 6 months with minimum of 16 hours per day. The non-braced group consisted of girls first seen for their spinal deformity, previously not treated. The groups presented similar curve pattern. Methods. Scoliometer exam: angle of trunk rotation at three levels of the spine: upper thoracic, main thoracic, lumbar or thoracolumbar. The maximal angle was noted at each level and the sum of three levels was calculated. Posterior trunk symmetry index (POTSI) and Hump Sum were measured using surface topography. Results Cobb angle was 34.9° ± 4.8° in braced and 32.7° ± 4.9° in un-braced patients (difference not significant). The age was 14.1 ± 1.6 years in braced patients and 13.1 ± 1.9 years in un-braced group (p = 0.046). The value of angle of trunk rotation in the main

Small vertebral cross-sectional area and tall intervertebral disc in adolescent idiopathic scoliosis.

PubMed

Ponrartana, Skorn; Fisher, Carissa L; Aggabao, Patricia C; Chavez, Thomas A; Broom, Alexander M; Wren, Tishya A L; Skaggs, David L; Gilsanz, Vicente

2016-09-01

When compared to boys, girls have smaller vertebral cross-sectional area, which conveys a greater spinal flexibility, and a higher prevalence of adolescent idiopathic scoliosis. To test the hypothesis that small vertebral cross-sectional area and tall intervertebral disc height are structural characteristics of patients with adolescent idiopathic scoliosis. Using multiplanar imaging techniques, measures of vertebral cross-sectional area, vertebral height and intervertebral disc height in the lumbar spine were obtained in 35 pairs of girls and 11 pairs of boys with and without adolescent idiopathic scoliosis of the thoracic spine matched for age, height and weight. Compared to adolescents without spinal deformity, girls and boys with adolescent idiopathic scoliosis had, on average, 9.8% (6.68 ± 0.81 vs. 7.40 ± 0.99 cm(2); P = 0.0007) and 13.9% (8.22 ± 0.84 vs. 9.55 ± 1.61 cm(2); P = 0.009) smaller vertebral cross-sectional dimensions, respectively. Additionally, patients with adolescent idiopathic scoliosis had significantly greater values for intervertebral disc heights (9.06 ± 0.85 vs. 7.31 ± 0.62 mm and 9.09 ± 0.87 vs. 7.61 ± 1.00 mm for girls and boys respectively; both P ≤ 0.011). Multiple regression analysis indicated that the presence of scoliosis was negatively associated with vertebral cross-sectional area and positively with intervertebral disc height, independent of sex, age and body mass index. We provide new evidence that girls and boys with adolescent idiopathic scoliosis have significantly smaller vertebral cross-sectional area and taller intervertebral disc heights - two major structural determinants that influence trunk flexibility. With appropriate validation, these findings may have implications for the identification of children at the highest risk for developing scoliosis.

Thrombospondin Type-1 Domain-Containing 7A in Idiopathic Membranous Nephropathy

PubMed Central

Meyer-Schwesinger, Catherine; Seitz-Polski, Barbara; Ma, Hong; Zahner, Gunther; Dolla, Guillaume; Hoxha, Elion; Helmchen, Udo; Dabert-Gay, Anne-Sophie; Debayle, Delphine; Merchant, Michael; Klein, Jon; Salant, David J.; Stahl, Rolf A.K.; Lambeau, Gérard

2014-01-01

BACKGROUND Idiopathic membranous nephropathy is an autoimmune disease. In approximately 70% of patients, it is associated with autoantibodies against the phospholipase A2 receptor 1 (PLA2R1). Antigenic targets in the remaining patients are unknown. METHODS Using Western blotting, we screened serum samples from patients with idiopathic membranous nephropathy, patients with other glomerular diseases, and healthy controls for antibodies against human native glomerular proteins. We partially purified a putative new antigen, identified this protein by means of mass spectrometry of digested peptides, and validated the results by analysis of recombinant protein expression, immunoprecipitation, and immunohistochemical analysis. RESULTS Serum samples from 6 of 44 patients in a European cohort and 9 of 110 patients in a Boston cohort with anti-PLA2R1–negative idiopathic membranous nephropathy recognized a glomerular protein that was 250 kD in size. None of the serum samples from the 74 patients with idiopathic membranous nephropathy who were sero-positive for anti-PLA2R1 antibodies, from the 76 patients with other glomerular diseases, and from the 44 healthy controls reacted against this antigen. Although this newly identified antigen is clearly different from PLA2R1, it shares some biochemical features, such as N-glycosylation, membranous location, and reactivity with serum only under nonreducing conditions. Mass spectrometry identified this antigen as thrombospondin type-1 domain-containing 7A (THSD7A). All reactive serum samples recognized recombinant THSD7A and immunoprecipitated THSD7A from glomerular lysates. Moreover, immunohistochemical analyses of biopsy samples from patients revealed localization of THSD7A to podocytes, and IgG eluted from one of these samples was specific for THSD7A. CONCLUSIONS In our cohort, 15 of 154 patients with idiopathic membranous nephropathy had circulating autoantibodies to THSD7A but not to PLA2R1, a finding that suggests a distinct

Continuous intravenous morphine infusion for postoperative analgesia following posterior spinal fusion for idiopathic scoliosis.

PubMed

Poe-Kochert, Connie; Tripi, Paul A; Potzman, Jennifer; Son-Hing, Jochen P; Thompson, George H

2010-04-01

A retrospective study of postoperative pain management. Evaluate the efficacy and safety of continuous intravenous morphine infusion for postoperative pain management in patients with idiopathic scoliosis (IS) undergoing posterior spinal fusion (PSF) and segmental spinal instrumentation (SSI). Postoperative pain is a common problem following surgery for IS. There are no published reports regarding the use of a continuous intravenous morphine infusion for this patient population. We retrospectively reviewed data regarding 339 consecutive patients with IS who underwent PSF and SSI between 1992 and 2006. All patients received intrathecal morphine after the induction of general anesthesia. Following surgery, preordered morphine infusion (0.01 mg/kg/h) was started at first reported pain. The infusion rate was titrated based on vital signs, visual analog scale (VAS) pain scores (0-10), and clinical status. It was continued until patients were able to take oral analgesics. We reviewed intrathecal morphine dosage, VAS pain scores through the third postoperative day, interval to start of morphine infusion, total morphine requirements in the first 48 hours, and any adverse reactions (nausea/vomiting, pruritus, respiratory depression, and pediatric intensive care unit admission). Mean intrathecal morphine dose was 15.5 +/- 3.9 microg/kg and mean interval to start of the intravenous morphine infusion was 17.5 +/- 5 hours. Mean VAS pain scores were 3.1, 4.5, 4.5, and 4.6 at 12 hours, 1, 2, and 3 days after surgery, respectively.The total mean morphine dose in the first 48 hours postoperatively was 0.03 +/- 0.01 mg/kg/h. Total morphine received was 1.44 +/- 0.5 mg/kg. Nausea/vomiting and pruritus, related to the morphine infusion occurred in 45 patients (13.3%) and 14 patients (4.1%), respectively. No patients had respiratory depression or required Pediatric Intensive Care Unit admission. A low frequency of adverse events and a mean postoperative VAS pain score of 5 or less

Narcolepsy Type 1 and Idiopathic Generalized Epilepsy: Diagnostic and Therapeutic Challenges in Dual Cases

PubMed Central

Baiardi, Simone; Vandi, Stefano; Pizza, Fabio; Alvisi, Lara; Toscani, Lucia; Zambrelli, Elena; Tinuper, Paolo; Mayer, Geert; Plazzi, Giuseppe

2015-01-01

Study Objectives: The aim of this study is to describe the possible co-occurrence of narcolepsy type 1 and generalized epilepsy, focusing on diagnostic challenge and safety of dual treatments. Methods and Results: Four patients with comorbidity for narcolepsy type 1 and idiopathic generalized epilepsy are reported: in three cases the onset of epilepsy preceded narcolepsy type 1 appearance, whereas in one case epileptic spells onset was subsequent. Patients presented with absences, myoclonic and tonic-clonic seizure type: in the patient with tonic-clonic seizures the dual pathology was easily recognized, in the other cases the first diagnosis caused the comorbid disease to be overlooked, independent of the time-course sequence. All four patients underwent neurological examination, video-electroencephalogram during which ictal and interictal epileptic discharges were recorded, and sleep polysomnographic studies. Repeated sleep onset rapid eye movement periods (SOREMPs) were documented with the multiple sleep latency test (MLST) in all the four cases. All patients had unremarkable brain magnetic resonance imaging studies and cerebrospinal hypocretin-1 was assessed in two patients, revealing undetectable levels. The association of antiepileptic drugs and substances currently used to treat narcolepsy type 1, including sodium oxybate, was effective in improving seizures, sleep disturbance, and cataplexy. Conclusions: Narcolepsy type 1 may occur in association with idiopathic generalized epilepsy, leading to remarkable diagnostic and therapeutic challenges. Electrophysiological studies as well as a comprehensive somnologic interview can help confirm the diagnosis in patients with ambiguous neurological history. Sodium oxybate in combination with antiepileptic drugs is safe and effective in treating cataplexy and excessive daytime sleepiness. Citation: Baiardi S, Vandi S, Pizza F, Alvisi L, Toscani L, Zambrelli E, Tinuper P, Mayer G, Plazzi G. Narcolepsy type 1 and

Scoliosis Research Society (SRS) Criteria and Society of Scoliosis Orthopaedic and Rehabilitation Treatment (SOSORT) 2008 Guidelines in Non-Operative Treatment of Idiopathic Scoliosis.

PubMed

Korbel, Krzysztof; Kozinoga, Mateusz; Stoliński, Łukasz; Kotwicki, Tomasz

2014-07-28

According to the Scoliosis Research Society (SRS), idiopathic scoliosis (IS) is a curvature of more than 10° Cobb angle, affecting 2-3% of pediatric population. Idiopathic scoliosis accounts for 80% of all scoliosis cases. Non-operative principles in the therapy of idiopathic scoliosis, including Scoliosis Research Society (SRS) criteria and guidelines proposed by the experts of the Society on Scoliosis Orthopedic and Rehabilitation Treatment (SOSORTS) were presented. The possibility to carry out quality of life assessments in a conservative procedure was also demonstrated. Based on the natural history of idiopathic scoliosis, SRS criteria, SOSORT 2008 experts' opinion and the knowledge of the possibilities of psychological assessment of conservative IS treatment, rules were proposed regarding nonsurgical IS therapy procedures, with special consideration being paid to the proper treatment start time (age, Risser test, biological maturity, Cobb angle), possibility of curvature progression, the importance of physiotherapy and psychological assessment. The knowledge of SRS criteria and SOSORT guidelines regarding the conservative treatment of IS are essential for proper treatment (the right time to start treatment), and supports establishment of interdisciplinary treatment teams, consisting of a physician, a physiotherapist, an orthopedic technician and a psychologist.

Blindness to Curvature and Blindness to Illusory Curvature.

PubMed

Bertamini, Marco; Kitaoka, Akiyoshi

2018-01-01

We compare two versions of two known phenomena, the Curvature blindness and the Kite mesh illusions, to highlight how similar manipulations lead to blindness to curvature and blindness to illusory curvature, respectively. The critical factor is a change in luminance polarity; this factor interferes with the computation of curvature along the contour, for both real and illusory curvature.

Comparison of Spinal Curvatures in the Sagittal Plane, as Well as Body Height and Mass in Polish Children and Adolescents Examined in the Late 1950s and in the Early 2000s.

PubMed

Mrozkowiak, Mirosław; Walicka-Cupryś, Katarzyna; Magoń, Grzegorz

2018-06-30

BACKGROUND Humans are exposed to various stimuli which lead to somatic modifications and changes in body posture, negatively affecting many of its characteristics. The purpose of this study was to assess significant alterations which occurred in selected morphological features and spinal curvatures in children and adolescents over a period of 40 years. MATERIAL AND METHODS The total of 7041 subjects, aged 4-18 years (mean age 11.3 years) were included in the study, which was designed to compare measurements performed in year 1959 (Group 1, n=3235 individuals) and in year 2003 (Group 2, n=3806 individuals). The children were examined for body height, body mass, as well as thoracic and lumbar curvatures. In 1959, the measurements were carried out using a spherodorsimeter, while in 2003, the CQ System photogrammetry was used, producing corresponding results. The Mann-Whitney U test and the Student's t-test were used for statistical analysis. RESULTS The findings showed a significant decrease in the angle of lumbar lordosis and in sacral inclination as well as an increase in body height and mass, particularly in prepubertal children. On the other hand, the angle of thoracic kyphosis and the partial angles of physiological spinal curvatures changed only to a small degree over the 40-year period. CONCLUSIONS This study provides evidence related to changes which occurred during the relevant period of over 40 years, namely a decrease in both the angle of lumbar lordosis and the sacral inclination angle, as well as an increase in body height and mass. These changes should be taken into consideration in selecting norms and standards applied in healthcare services, and the findings suggest it is necessary to regularly update such standards.

Exercises for adolescent idiopathic scoliosis.

PubMed

Romano, Michele; Minozzi, Silvia; Bettany-Saltikov, Josette; Zaina, Fabio; Chockalingam, Nachiappan; Kotwicki, Tomasz; Maier-Hennes, Axel; Negrini, Stefano

2012-08-15

Adolescent idiopathic scoliosis (AIS) is a three-dimensional deformity of the spine . While AIS can progress during growth and cause a surface deformity, it is usually not symptomatic. However, in adulthood, if the final spinal curvature surpasses a certain critical threshold, the risk of health problems and curve progression is increased. The use of scoliosis-specific exercises (SSE) to reduce progression of AIS and postpone or avoid other more invasive treatments is controversial. To evaluate the efficacy of SSE in adolescent patients with AIS. The following databases (up to 30 March 2011) were searched with no language limitations: CENTRAL (The Cochrane Library 2011, issue 2), MEDLINE (from January 1966), EMBASE (from January 1980), CINHAL (from January 1982), SportDiscus (from January 1975), PsycInfo (from January 1887), PEDro (from January 1929). We screened reference lists of articles and also conducted an extensive handsearch of grey literature. Randomised controlled trials and prospective cohort studies with a control group comparing exercises with no treatment, other treatment, surgery, and different types of exercises. Two review authors independently selected studies, assessed risk of bias and extracted data. Two studies (154 participants) were included. There is low quality evidence from one randomised controlled study that exercises as an adjunctive to other conservative treatments increase the efficacy of these treatments (thoracic curve reduced: mean difference (MD) 9.00, (95% confidence interval (CI) 5.47 to 12.53); lumbar curve reduced:MD 8.00, (95% CI 5.08 to 10.92)). There is very low quality evidence from a prospective controlled cohort study that scoliosis-specific exercises structured within an exercise programme can reduce brace prescription (risk ratio (RR) 0.24, (95% CI 0.06 to1.04) as compared to usual physiotherapy (many different kinds of general exercises according to the preferences of the single therapists within different facilities

Differentiation of idiopathic spinal cord herniation from dorsal arachnoid webs on MRI and CT myelography.

PubMed

Schultz, Randall; Steven, Andrew; Wessell, Aaron; Fischbein, Nancy; Sansur, Charles A; Gandhi, Dheeraj; Ibrahimi, David; Raghavan, Prashant

2017-06-01

OBJECTIVE Dorsal arachnoid webs (DAWs) and spinal cord herniation (SCH) are uncommon abnormalities affecting the thoracic spinal cord that can result in syringomyelia and significant neurological morbidity if left untreated. Differentiating these 2 entities on the basis of clinical presentation and radiological findings remains challenging but is of vital importance in planning a surgical approach. The authors examined the differences between DAWs and idiopathic SCH on MRI and CT myelography to improve diagnostic confidence prior to surgery. METHODS Review of the picture archiving and communication system (PACS) database between 2005 and 2015 identified 6 patients with DAW and 5 with SCH. Clinical data including demographic information, presenting symptoms and neurological signs, and surgical reports were collected from the electronic medical records. Ten of the 11 patients underwent MRI. CT myelography was performed in 3 patients with DAW and in 1 patient with SCH. Imaging studies were analyzed by 2 board-certified neuroradiologists for the following features: 1) location of the deformity; 2) presence or absence of cord signal abnormality or syringomyelia; 3) visible arachnoid web; 4) presence of a dural defect; 5) nature of dorsal cord indentation (abrupt "scalpel sign" vs "C"-shaped); 6) focal ventral cord kink; 7) presence of the nuclear trail sign (endplate irregularity, sclerosis, and/or disc-space calcification that could suggest a migratory path of a herniated disc); and 8) visualization of a complete plane of CSF ventral to the deformity. RESULTS The scalpel sign was positive in all patients with DAW. The dorsal indentation was C-shaped in 5 of 6 patients with SCH. The ventral subarachnoid space was preserved in all patients with DAW and interrupted in cases of SCH. In no patient was a web or a dural defect identified. CONCLUSIONS DAW and SCH can be reliably distinguished on imaging by scrutinizing the nature of the dorsal indentation and the integrity of

The effect of compliance to a Rigo System Cheneau brace and a specific exercise programme on idiopathic scoliosis curvature: a comparative study: SOSORT 2014 award winner

PubMed Central

2014-01-01

Background There is controversy as to whether conservative management that includes wearing a brace and exercises is effective in stabilising idiopathic scoliosis curves. A brace only prevents progression of the curve and has been shown to have favourable outcomes when patients are compliant. So the aim of this study was to: determine the effect of compliance to the Rigo System Cheneau (RSC) brace and a specific exercise programme on Idiopathic Scoliosis curvature; and to compare the Quality of Life (QoL) and psychological traits of compliant and non compliant subjects. Methods A pre/post test study design was used with a post study comparison between subjects who complied with the management and those who did not. Fifty one subjects, girls aged 12-16 years, Cobb angles 20-50 degrees participated in the study. Subjects were divided into two groups, according to their compliance, at the end of the study. The compliant group wore the brace 20 or more hours a day and exercised three or more times per week. The non-compliant group wore the brace less than 20 hours a day and exercised less than three times per week. Cobb angles, vertebral rotation, scoliometer readings, peak flow, quality of life and personality traits were compared between groups, using the student’s two sample t-test and an analysis of covariance. Results The compliant group, wore the brace 21.5 hours per day and exercised four times a week, and significantly improved in all measures compared to non compliant subjects, who wore the brace 12 hours per day, exercised 1.7 times a week and significantly deteriorated (p < 0.0001). The major Cobb angles in the compliant group improved 10.19°(±5.5) and deteriorated 5.52°(±4.3) in the non compliant group (p < 0.0001). Compliant subjects had a significantly better QoL than the non compliant subjects (p = 0.001). The compliant group were significantly more emotionally mature, stable and realistic than the non compliant group (p = 0

The impact of curve severity on obstetric complications and regional anesthesia utilization in pregnant patients with adolescent idiopathic scoliosis: a preliminary analysis.

PubMed

Chan, Emily W; Gannon, Stephen R; Shannon, Chevis N; Martus, Jeffrey E; Mencio, Gregory A; Bonfield, Christopher M

2017-10-01

OBJECTIVE Adolescent idiopathic scoliosis (AIS), the most common type of scoliosis, often presents immediately prior to a woman's childbearing years; however, research investigating the impact of AIS on women's health, particularly pregnancy delivery outcomes, is sparse, with existing literature reporting mixed findings. Similarly limited are studies examining the change in scoliotic curve during or after pregnancy. Therefore, this study aims to determine 1) the impact of scoliotic curvature on obstetric complications (preterm births, induction of labor, and urgent/emergency caesarean section delivery), 2) regional anesthetic decision making and success during delivery for these patients, and 3) the effect of pregnancy on curve progression. METHODS Records of all pregnant patients diagnosed with AIS at the authors' institution who delivered between January 2002 and September 2016 were retrospectively reviewed. Demographic information, pre- and postpartum radiographic Cobb angles, and clinical data for each pregnancy and delivery were recorded and analyzed. The Wilcoxon rank-sum test and the Wilcoxon signed-rank test were used for statistical analyses. RESULTS Fifty-nine patients (84 deliveries) were included; 14 patients had undergone prior posterior spinal fusion. The median age at AIS diagnosis was 15.2 years, and the median age at delivery was 21.8 years. Overall, the median major Cobb angle prior to the first pregnancy was 25° (IQR 15°-40°). Most births were by spontaneous vaginal delivery (n = 45; 54%); elective caesarean section was performed in 17 deliveries (20%). Obstetric complications included preterm birth (n = 18; 21.4%), induction of labor (n = 20; 23.8%), and urgent/emergency caesarean section (n = 12; 14.0%); none were associated with severity of scoliosis curve or prior spinal fusion. Attempts at spinal anesthesia were successful 99% of the time (70/71 deliveries), even among the patients who had undergone prior spinal fusion (n = 13). There

Sagittal Balance in Adolescent Idiopathic Scoliosis

PubMed Central

Xu, Xi-Ming; Wang, Fei; Zhou, Xiao-Yi; Liu, Zi-Xuan; Wei, Xian-Zhao; Bai, Yu-Shu; Li, Ming

2015-01-01

Abstract The relationship between spinal sagittal alignment and pelvic parameters is well known in adolescent idiopathic scoliosis. However, few studies have reported the sagittal spinopelvic relationship after selective posterior fusion of thoracolumbar/lumbar (TL/L) curves. We evaluated the relationship between spinal sagittal alignment and the pelvis, and analyzed how the pelvic sagittal state is adjusted in Lenke type 5C patients. We conducted a retrospective study of 36 patients with Lenke type 5C curves who received selective posterior TL/L curve fusion. Coronal and spinopelvic sagittal parameters were pre and postoperatively compared. Pearson coefficients were used to analyze the correlation between all spinopelvic sagittal parameters before and after surgery. We also evaluated 3 pelvic morphologies (anteverted, normal, and retroverted) before and after surgery. Preoperatively, the mean pelvic incidence was 46.0°, with a pelvic tilt and sacral slope (SS) of 8.2° and 37.8°, respectively, and 25% (9/36) of patients had an anteverted pelvis, whereas the other 75% had a normal pelvis. Postoperatively, 42% (15/36) of patients had a retroverted pelvis, 53% (19/36) had a normal pelvis, and 2 patients had an anteverted pelvis. Logistic regression analyses yielded 2 factors that were significantly associated with the risk for a postoperative unrecovered anteverted pelvis, including increased lumbar lordosis (LL) (odds ratio [OR] 4.8, P = 0.029) and increased SS (OR 5.6, P = 0.018). Four factors were significantly associated with the risk of a postoperative newly anteverted pelvis, including LL at the final follow-up (OR 6.9, P = 0.009), increased LL (OR 8.9, P = 0.003), LL below fusion (OR 9.4, P = 0.002), and increased SS (OR 11.5, P = 0.001). The pelvic state may be adjusted after selective posterior TL/L curve fusion in Lenke 5C adolescent idiopathic scoliosis patients. It is difficult to improve an anteverted pelvis in patients who have

The Prevalence of Idiopathic Scoliosis in Eleven Year-Old Korean Adolescents: A 3 Year Epidemiological Study

PubMed Central

Lee, Jin-Young; Moon, Seong-Hwan; Kim, Han Jo; Suh, Bo-Kyung; Nam, Ji Hoon; Jung, Jae Kyun; Lee, Hwan-Mo

2014-01-01

Purpose School screening allows for early detection and early treatment of scoliosis, with the purpose of reducing the number of patients requiring surgical treatment. Children between 10 and 14 years old are considered as good candidates for school screening tests of scoliosis. The purpose of the present study was to assess the epidemiological findings of idiopathic scoliosis in 11-year-old Korean adolescents. Materials and Methods A total of 37856 11-year-old adolescents were screened for scoliosis. There were 17110 girls and 20746 boys. Adolescents who were abnormal by Moiré topography were subsequently assessed by standardized clinical and radiological examinations. A scoliotic curve was defined as 10° or more. Results The prevalence of scoliosis was 0.19% and most of the curves were small (10° to 19°). The ratio of boys to girls was 1:5.5 overall. Sixty adolescents (84.5%) exhibited single curvature. Thoracolumbar curves were the most common type of curve identified, followed by thoracic and lumbar curves. Conclusion The prevalence of idiopathic scoliosis among 11-year-old Korean adolescents was 0.19%. PMID:24719147

[Bracing in Adolescent Idiopathic Scoliosis].

PubMed

Lo, Yi-Fang; Huang, Yu-Chu

2017-04-01

Scoliosis is a common medical problem, with an incidence of between 0.47% and 5.2% in the general population globally. Adolescent idiopathic scoliosis (AIS) accounts for nearly 80% of all scoliosis. Young people with AIS often experience negative social consequences in association with their condition. Without proper and timely treatment, the potential resulting disabilities range from trunk deformity, pain, and neurological complications to compromised cardiopulmonary function, all of which may cause lifelong suffering. Scoliosis may be treated either conservatively or surgically, based on the severity of the disease. Bracing is the most widely adopted method of conservative treatment. However, the main goal of bracing is to inhibit the progression of the spinal curvature rather than to cure scoliosis. The clinical effectiveness of bracing in Taiwan has often been underutilized as a result of financial or other factors such as the availability of the treatment. The purpose of the present review is to clarify the effectiveness of bracing for AIS by elucidating the pathophysiology of scoliosis and examining the recent clinical evidence. The importance of preventative care and the unique contribution of nursing care to treatment has to date been under-recognized. The positive support that nurses provide to the families of the patients during the early phases of treatment as well as to the patients themselves, including helping them exercise appropriately and wear the brace correctly, is an essential component of effective treatment. Learning how to work with and to adapt to the brace being part of the body is an important part of the treatment as well as a way to avoid pain. Nurses are in an ideal position to facilitate this learning process and, overall, to provide health education.

Simultaneous double-rod rotation technique in posterior instrumentation surgery for correction of adolescent idiopathic scoliosis.

PubMed

Ito, Manabu; Abumi, Kuniyoshi; Kotani, Yoshihisa; Takahata, Masahiko; Sudo, Hideki; Hojo, Yoshihiro; Minami, Akio

2010-03-01

The authors present a new posterior correction technique consisting of simultaneous double-rod rotation using 2 contoured rods and polyaxial pedicle screws with or without Nesplon tapes. The purpose of this study is to introduce the basic principles and surgical procedures of this new posterior surgery for correction of adolescent idiopathic scoliosis. Through gradual rotation of the concave-side rod by 2 rod holders, the convex-side rod simultaneously rotates with the the concave-side rod. This procedure does not involve any force pushing down the spinal column around the apex. Since this procedure consists of upward pushing and lateral translation of the spinal column with simultaneous double-rod rotation maneuvers, it is simple and can obtain thoracic kyphosis as well as favorable scoliosis correction. This technique is applicable not only to a thoracic single curve but also to double major curves in cases of adolescent idiopathic scoliosis.

Comparison of parameters of spinal curves in the sagittal plane measured by photogrammetry and inclinometry.

PubMed

Walicka-Cupryś, Katarzyna; Drzał-Grabiec, Justyna; Mrozkowiak, Mirosław

2013-10-31

BACKGROUND. The photogrammetric method and inclinometer-based measurements are commonly employed to assess the anteroposterior curvatures of the spine. These methods are used both in clinical trials and for screening purposes. The aim of the study was to compare the parameters used to characterise the anteroposterior spinal curvatures as measured by photogrammetry and inclinometry. MATERIAL AND METHODS. The study enrolled 341 subjects: 169 girls and 172 boys, aged 4 to 9 years, from kindergartens and primary schools in Rzeszów. The anteroposterior spinal curvatures were examined by photogrammetry and with a mechanical inclinometer. RESULTS. There were significant differences in the α angle between the inclinometric and photogrammetric assessment in the Student t test (p=0.017) and the Fisher Snedecor test (p=0.0001), with similar differences in the β angle (Student's t p=0.0001, Fisher Snedecor p=0.007). For the γ angle, significant differences were revealed with Student's t test (p=0.0001), but not with the Fisher Snedecor test (p = 0.22). CONCLUSIONS. 1. Measurements of inclination of particular segments of the spine obtained with the photogrammetric method and the inclinometric method in the same study group revealed statistically significant differences. 2. The results of measurements obtained by photogrammetry and inclinometry are not comparable. 3. Further research on agreement between measurements of the anteroposterior spinal curvatures obtained using the available measurement equipment is recommended.

Idiopathic ventricular tachycardia and fibrillation.

PubMed

Belhassen, B; Viskin, S

1993-06-01

Important data have recently been added to our understanding of sustained ventricular tachyarrhythmias occurring in the absence of demonstrable heart disease. Idiopathic ventricular tachycardia (VT) is usually of monomorphic configuration and can be classified according to its site of origin as either right monomorphic (70% of all idiopathic VTs) or left monomorphic VT. Several physiopathological types of monomorphic VT can be presently individualized, according to their mode of presentation, their relationship to adrenergic stress, or their response to various drugs. The long-term prognosis is usually good. Idiopathic polymorphic VT is a much rarer type of arrhythmia with a less favorable prognosis. Idiopathic ventricular fibrillation may represent an underestimated cause of sudden cardiac death in ostensibly healty patients. A high incidence of inducibility of sustained polymorphic VT with programmed ventricular stimulation has been found by our group, but not by others. Long-term prognosis on Class IA antiarrhythmic medications that are highly effective at electrophysiologic study appears excellent.

Fully automatic measurements of axial vertebral rotation for assessment of spinal deformity in idiopathic scoliosis

NASA Astrophysics Data System (ADS)

Forsberg, Daniel; Lundström, Claes; Andersson, Mats; Vavruch, Ludvig; Tropp, Hans; Knutsson, Hans

2013-03-01

Reliable measurements of spinal deformities in idiopathic scoliosis are vital, since they are used for assessing the degree of scoliosis, deciding upon treatment and monitoring the progression of the disease. However, commonly used two dimensional methods (e.g. the Cobb angle) do not fully capture the three dimensional deformity at hand in scoliosis, of which axial vertebral rotation (AVR) is considered to be of great importance. There are manual methods for measuring the AVR, but they are often time-consuming and related with a high intra- and inter-observer variability. In this paper, we present a fully automatic method for estimating the AVR in images from computed tomography. The proposed method is evaluated on four scoliotic patients with 17 vertebrae each and compared with manual measurements performed by three observers using the standard method by Aaro-Dahlborn. The comparison shows that the difference in measured AVR between automatic and manual measurements are on the same level as the inter-observer difference. This is further supported by a high intraclass correlation coefficient (0.971-0.979), obtained when comparing the automatic measurements with the manual measurements of each observer. Hence, the provided results and the computational performance, only requiring approximately 10 to 15 s for processing an entire volume, demonstrate the potential clinical value of the proposed method.

Equal-Curvature X-Ray Telescopes

NASA Technical Reports Server (NTRS)

Saha, Timo T.; Zhang, William

2002-01-01

We introduce a new type of x-ray telescope design; an Equal-Curvature telescope. We simply add a second order axial sag to the base grazing incidence cone-cone telescope. The radius of curvature of the sag terms is the same on the primary surface and on the secondary surface. The design is optimized so that the on-axis image spot at the focal plane is minimized. The on-axis RMS (root mean square) spot diameter of two studied telescopes is less than 0.2 arc-seconds. The off-axis performance is comparable to equivalent Wolter type 1 telescopes.

Spontaneous regression of curve in immature idiopathic scoliosis - does spinal column play a role to balance? An observation with literature review.

PubMed

Modi, Hitesh N; Suh, Seung-Woo; Yang, Jae-Hyuk; Hong, Jae-Young; Venkatesh, Kp; Muzaffar, Nasir

2010-11-04

Child with mild scoliosis is always a subject of interest for most orthopaedic surgeons regarding progression. Literature described Hueter-Volkmann theory regarding disc and vertebral wedging, and muscular imbalance for the progression of adolescent idiopathic scoliosis. However, many authors reported spontaneous resolution of curves also without any reason for that and the rate of resolution reported is almost 25%. Purpose of this study was to question the role of paraspinal muscle tuning/balancing mechanism, especially in patients with idiopathic scoliosis with early mild curve, for spontaneous regression or progression as well as changing pattern of curves. An observational study of serial radiograms in 169 idiopathic scoliosis children (with minimum follow-up one year) was carried. All children with Cobb angle < 25° and who were diagnosed for the first time were selected. As a sign of immaturity at the time of diagnosis, all children had Risser sign 0. No treatment was given to entire study group. Children were divided in three groups at final follow-up: Group A, B and C as children with regression, no change and progression of their curves, respectively. Additionally changes in the pattern of curve were also noted. Average age was 9.2 years at first visit and 10.11 years at final follow-up with an average follow-up of 21 months. 32.5% (55/169), 41.4% (70/169) and 26% (44/169) children exhibited regression, no change and progression in their curves, respectively. 46.1% of children (78/169) showed changing pattern of their curves during the follow-up visits before it settled down to final curve. Comparing final fate of curve with side of curve and number of curves it did not show any relationship (p > 0.05) in our study population. Possible reason for changing patterns could be better explained by the tuning/balancing mechanism of spinal column that makes an effort to balance the spine and result into spontaneous regression or prevent further progression of

Do adolescents with idiopathic scoliosis have body schema disorders? A cross-sectional study.

PubMed

Picelli, Alessandro; Negrini, Stefano; Zenorini, Andrea; Iosa, Marco; Paolucci, Stefano; Smania, Nicola

2016-01-01

To date etiology of adolescent idiopathic scoliosis appears complex and still remains unclear. A distorted body schema has been proposed to be a part of a sequence of pathological events in the development of adolescent idiopathic scoliosis. To investigate the awareness of trunk misalignment in adolescents with idiopathic scoliosis. Information about 44 adolescents with idiopathic scoliosis was collected as follows: age; sex; handedness; family history of scoliosis; back pain; sport practice; shoulder and waist line symmetry; leg length; dorsal kyphosis; back hump; rehabilitation; scoliotic curve; Risser sign. We evaluated awareness of trunk misalignment with a graphic table displaying pictures of progressively increasing scoliotic curves. Patients were asked to indicate which picture corresponded to their perceived own spinal alignment. Patients with thoracolumbar scoliosis overestimated their actual thoracic spine curve. Patients with thoracic-thoracolumbar scoliosis underestimated their actual thoracolumbar spine curve and overestimated their actual lumbar spine curve. Scoliotic curve > 15°, double curve, younger age, back pain, family history of scoliosis and lower Risser score related with a misperception of trunk alignment. Our results support the hypothesis that adolescents with idiopathic scoliosis have an altered corporeal awareness of their trunk alignment.

Screening for Adolescent Idiopathic Scoliosis: Evidence Report and Systematic Review for the US Preventive Services Task Force.

PubMed

Dunn, John; Henrikson, Nora B; Morrison, Caitlin C; Blasi, Paula R; Nguyen, Matt; Lin, Jennifer S

2018-01-09

Adolescent idiopathic scoliosis (AIS), a spinal curvature of 10° or more, is the most common form of scoliosis, with a prevalence of 1% to 3%. Curves progress in approximately two-thirds of patients with AIS before skeletal maturity, and large curves (>50°) may be associated with adverse health outcomes. To systematically review evidence on benefits and harms of AIS screening for the US Preventive Services Task Force (USPSTF). Cochrane Central Register of Controlled Trials, MEDLINE, ERIC, PubMed, CINAHL, and relevant systematic reviews were searched for studies published from January 1966 to October 20, 2016; studies included in a previous USPSTF report were also reviewed. Surveillance was conducted through July 24, 2017. Fair- and good-quality studies that evaluated the accuracy of screening children and adolescents aged 10 to 18 years for AIS, the benefits of AIS treatment, the harms of AIS screening or treatment, or long-term health outcomes. Two investigators independently reviewed abstracts and full-text articles and extracted data into evidence tables. Results were qualitatively summarized. Health outcomes and spinal curvature in adolescence and adulthood, accuracy of screening for AIS, any harm of AIS screening or treatment. Fourteen studies (N = 448 276) in 26 articles were included. Accuracy of AIS screening was highest (93.8% sensitivity; 99.2% specificity) in a cohort study of a clinic-based program using forward bend test, scoliometer, and Moiré topography screening (n = 306 082); accuracy was lower in cohort studies of 6 programs using fewer modalities (n = 141 161). Four controlled studies (n = 587) found evidence for benefit of bracing on curve progression compared with controls. A randomized clinical trial and a nonrandomized trial of exercise treatment (N = 184) found favorable reductions in Cobb angle of 0.67° to 4.9° in the intervention group compared with increases of 1.38° to 2.8° in the control group. Two

Sagittal plane analysis of selective posterior thoracic spinal fusion in adolescent idiopathic scoliosis: a comparison study of all pedicle screw and hybrid instrumentation.

PubMed

Liu, Tie; Hai, Yong

2014-07-01

To compare sagittal profiles of selective posterior thoracic instrumentation with segmental pedicle screws instrumentation and hybrid (hook and pedicle screw). Nowadays, thoracic screws are considered more effective than other constructs in spinal deformity correction and have become the treatment in adolescent idiopathic scoliosis surgery. However, recent research found that this enhanced correction ability may sacrifice sagittal balance. As lumbar lordosis is dependent upon thoracic kyphosis (TK), it has been important to maintain TK magnitude in selective thoracic fusions to keep balance. There is no sagittal measurement analysis between the hybrid and all-screw constructs type in cases of selective thoracic fusion. All adolescent idiopathic scoliosis (Lenke1) patients surgically treated in our department between 2003 and 2008 were reviewed. Radiographs of these patients, whose preoperative, immediately postoperative, and minimum 2-year follow-up after selective thoracic fusion (lower instrumented vertebrae not lower than L1, hybrid group the pedicle screw instrumentation not higher than T10) were evaluated, 21 patients underwent posterior hybrid instrumentation and 21 underwent pedicle screw instrumentation. No significant difference in sagittal profiles was observed between the 2 groups. At final follow-up, the proximal junctional measurement has a minor increase in both the groups. TK (T5-T12) also increased (+2.0 degrees of increase in hybrid group vs. +3.9 degrees of increase in the pedicle screw group). The effect of different instrumentation in changing TK at various time points between 2 groups was statistic different (P=0.004). Lumbar lordosis (L1-L5) was increased in both the groups. No significant changes in distal junctional measurement and thoracolumbar junction were noted. The C7 sagittal plumbline remained negative in both the groups at the final follow-up. There was no statistically significant difference comparing the sagittal alignment

MRI Evaluation of Spinal Length and Vertebral Body Angle During Loading with a Spinal Compression Harness

NASA Technical Reports Server (NTRS)

Campbell, James A.; Hargens, Alan R.; Murthy, G.; Ballard, R. E.; Watenpaugh, D. E.; Hargens, Alan, R.; Sanchez, E.; Yang, C.; Mitsui, I.; Schwandt, D.;

Comparison of two spinal needle types to achieve a unilateral spinal block.

PubMed

Kuusniemi, Kristiina; Leino, Kari; Lertola, Kaarlo; Pihlajamäki, Kalevi; Pitkänen, Mikko

2013-04-01

Unilateral spinal anesthesia is beneficial in patients undergoing unilateral leg surgery. The direction and the shape of the spinal needle are thought to influence the unilateral distribution of the local anesthetic in the intrathecal space. Therefore, to study the effects of different spinal needles we compared the effects of the Whitacre and Quincke spinal needles. This was a prospective, randomized, double-blind study of 60 consecutive outpatients scheduled for unilateral lower-limb surgery. The patients were randomized to receive spinal anesthesia with 1.2 ml of 0.5 % plain bupivacaine using either a 27-G Whitacre or a Quincke needle. One half of the local anesthetic was injected towards the nondependent side and the other half was directed cranially. The spread of spinal anesthesia, both sensory and motor blocks, was defined as the primary endpoint and was recorded at 10, 20, and 30 min after the spinal injection, at the end of the operation, 2 h after the spinal injection, and every 30 min thereafter until there was no motor block. Secondary endpoints included patient satisfaction and adverse effects. There was no difference in the spread of sensory or motor blocks between the Whitacre and the Quincke groups. However, the sensory and motor blocks on the operated and the nonoperated sides were significantly different at all testing times, as expected. There was no difference in the incidence of adverse effects or patient satisfaction scores between the Whitacre and the Quincke groups. Unilateral spinal block for outpatient surgery can be achieved with both pencil-point (Whitacre) and Quincke needles using 6.0 mg of plain bupivacaine. Neither the spread of sensory and motor blocks nor the corresponding recovery times appeared to be different between the groups. Nor was there any difference in patient satisfaction.

The concept of geodesic curvature applied to optical surfaces.

PubMed

Barbero, Sergio

2015-07-01

To propose geodesic curvature as a metric to characterise how an optical surface locally differs from axial symmetry. To derive equations to evaluate geodesic curvatures of arbitrary surfaces expressed in polar coordinates. The concept of geodesic curvature is explained in detail as compared to other curvature-based metrics. Starting with the formula representing a surface as function of polar coordinates, an equation for the geodesic curvature is obtained depending only on first and second radial and first order angular derivatives of the surface function. The potential of the geodesic curvature is illustrated using different surface tests. Geodesic curvature reveals local axial asymmetries more sharply than other types of curvatures such as normal curvatures. Geodesic curvature maps could be used to characterise local axial asymmetries for relevant optometry applications such as corneal topography anomalies (keratoconus) or ophthalmic lens metrology. © 2015 The Authors Ophthalmic & Physiological Optics © 2015 The College of Optometrists.

Reversal of childhood idiopathic scoliosis in an adult, without surgery: a case report and literature review

PubMed Central

2009-01-01

Background Some patients with mild or moderate thoracic scoliosis (Cobb angle <50-60 degrees) suffer disproportionate impairment of pulmonary function associated with deformities in the sagittal plane and reduced flexibility of the spine and chest cage. Long-term improvement in the clinical signs and symptoms of childhood onset scoliosis in an adult, without surgical intervention, has not been documented previously. Case presentation A diagnosis of thoracic scoliosis (Cobb angle 45 degrees) with pectus excavatum and thoracic hypokyphosis in a female patient (DOB 9/17/52) was made in June 1964. Immediate spinal fusion was strongly recommended, but the patient elected a daily home exercise program taught during a 6-week period of training by a physical therapist. This regime was carried out through 1992, with daily aerobic exercise added in 1974. The Cobb angle of the primary thoracic curvature remained unchanged. Ongoing clinical symptoms included dyspnea at rest and recurrent respiratory infections. A period of multimodal treatment with clinical monitoring and treatment by an osteopathic physician was initiated when the patient was 40 years old. This included deep tissue massage (1992-1996); outpatient psychological therapy (1992-1993); a daily home exercise program focused on mobilization of the chest wall (1992-2005); and manipulative medicine (1994-1995, 1999-2000). Progressive improvement in chest wall excursion, increased thoracic kyphosis, and resolution of long-standing respiratory symptoms occurred concomitant with a >10 degree decrease in Cobb angle magnitude of the primary thoracic curvature. Conclusion This report documents improved chest wall function and resolution of respiratory symptoms in response to nonsurgical approaches in an adult female, diagnosed at age eleven years with idiopathic scoliosis. PMID:20003501

Scoliosis and school screening for spinal deformity.

PubMed

Kane, W J; Brown, J C; Hensinger, R N; Keller, R B

1978-05-01

The onset of "idiopathic" scoliosis is gradual. It goes unnoticed by parent and child alike. The problem is often not detected until the curvature has progressed. Severe scoliosis has serious long-term systemic, cosmetic and psychologic effects. School-based screening programs are very effective in reducing the number of operations required. These programs can be carried out by school nurses, physical education teachers and volunteers who are trained by a knowledgeable physician. Brace treatment is successful when scoliosis is detected only.

Full fusion of proximal thoracic curve helps to prevent postoperative cervical tilt in Lenke type 2 adolescent idiopathic scoliosis patients with right-elevated shoulder.

PubMed

Jiang, Jun; Qian, Bang-Ping; Qiu, Yong; Wang, Bin; Yu, Yang; Zhu, Ze-Zhang

2017-08-23

To date, no study had reported the phenomenon of deteriorated postoperative cervical tilt in Lenke type 2 adolescent idiopathic scoliosis patients. The purpose of this study is to evaluate the cervical tilt in Lenke type 2 adolescent idiopathic scoliosis patients with right-elevated shoulder treated by either full fusion or partial/non fusion of the proximal thoracic curve. A total of 30 Lenke type 2 AIS patients with preoperative right-elevated shoulder underwent posterior spinal instrumentation from 2009 to 2011 were included in this study. All the subjects were divided into 2 groups according to the selection of upper instrumented vertebra. There were 14 cases proximally fused to T1 or T2 (Group A) and 16 cases proximally fused to T3 or below (Group B). Both standing anteroposterior and sagittal X-ray films of the spine obtained preoperatively, one week after the operation, and at a minimum of two-year follow-up were analyzed with respect to the following parameters: cervical tilt, T1 tilt, proximal thoracic Cobb angle, main thoracic Cobb angle, apical vertebral translation of proximal thoracic curve, apical vertebral translation of main thoracic curve, radiographic shoulder height, cervical lordosis, proximal thoracic kyphosis and main thoracic kyphosis. Most (83.3%) of the patients in these two groups gained satisfactory shoulder balance after surgery. However, the cervical tilt significantly improved in group A (p < 0.001) but deteriorated in group B (p < 0.001). In group A, the decrease of cervical tilt significantly positively correlated with that of T1 tilt (p < 0.001). In group B, the increase of cervical tilt significantly positively correlated with both the increase of T1 tilt (p < 0.001) and the increase of apical vertebral translation of proximal thoracic curve (p < 0.05). Lenke type 2 AIS patients with right-elevated shoulder gain improved shoulder but deteriorated cervical tilt after partial/non fusion of proximal thoracic curve. Full

[Severe idiopathic scoliosis. Does the approach and the instruments used modify the results?].

PubMed

Sánchez-Márquez, J M; Sánchez Pérez-Grueso, F J; Pérez Martín-Buitrago, M; Fernández-Baíllo, N; García-Fernández, A; Quintáns-Rodríguez, J

2014-01-01

The aim of this work is to evaluate and compare the radiographic results and complications of the surgical treatment of adolescents with idiopathic scoliosis greater than 75 degrees, using a double approach (DA) or an isolated posterior approach with hybrid instruments (posterior hybrid [PH]), or with «all-pedicle screws» (posterior screws [PS]). A retrospective review was performed on 69 patients with idiopathic scoliosis greater than 75°, with a follow-up of more than 2 years, to analyze the flexibility of the curves, the correction obtained, and the complications depending on the type of surgery. The Kruskal-Wallis test for non-parametric variables was used for the statistical analysis. There were no statistically significant differences between the 3 patient groups in the pre-surgical Cobb angle values (DA=89°, PH=83°, PS=83°), in the immediate post-surgical (DA=34°, PH=33°, PS=30°), nor at the end of follow-up (DA=36°, PH=36°, PS=33°) (P>.05). The percentage correction (DA=60%, PH=57%, PS=60%) was similar between groups (P>.05). The percentage of complications associated with the procedure was 20.8% in DA, 10% in PH and 20% in PS. Two patients in the PS group showed changes, with no neurological lesions, in the spinal cord monitoring, and one patient in the same group suffered a delayed and transient incomplete lesion. No significant differences were observed in the correction of severe idiopathic scoliosis between patients operated using the double or isolated posterior approach, regardless of the type of instrumentation used. Copyright © 2013 SECOT. Published by Elsevier Espana. All rights reserved.

Does Vertical Ground Reaction Force of the Hip, Knee, and Ankle Joints Change in Patients with Adolescent Idiopathic Scoliosis after Spinal Fusion?

PubMed

Yusof, Mohd Imran; Shaharudin, Shazlin; Sivalingarajah, Prema

2018-04-01

Comparative cross-sectional study. We measured the vertical ground reaction force (vGRF) of the hip, knee, and ankle joints during normal gait in normal patients, adolescent idiopathic scoliosis (AIS) patients with a Cobb angle <40° and in AIS patients with spinal fusion. We aimed to investigate whether vGRF in the aforementioned joints is altered in these three groups of patients. vGRF of the lower limb joints may be altered in these groups of patients. Although it is known that excessive force in the joints may induce early arthritis, there is limited relevant information in the literatures. We measured vGRF of the hip, knee, and ankle joints during heel strike, early stance, mid stance, and toe-off phases in normal subjects (group 1, n=14), AIS patients with Cobb angle <40° (group 2, n=14), and AIS patients with spinal fusion (group 3, n=13) using a gait analysis platform. Fifteen auto-reflective tracking markers were attached to standard anatomical landmarks in both the lower limbs. The captured motion images were used to define the orientations of the body segments and force exerted on the force plate using computer software. Statistical analysis was performed using independent t-test and analysis of variance to examine differences between the right and left sides as well as those among the different subject groups. The measurements during the four gait phases in all the groups did not show any significant difference ( p >0.05). In addition, no significant difference was found in the vGRF measurements of all the joints among the three groups ( p >0.05). A Cobb angle <40° and spinal fusion did not significantly create imbalance or alter vGRF of the lower limb joints in AIS patients.

Spinal postural training: Comparison of the postural and mobility effects of electrotherapy, exercise, biofeedback trainer in addition to postural education in university students.

PubMed

Çelenay, Şeyda Toprak; Kaya, Derya Özer; Özüdoğru, Anıl

2015-01-01

Spinal posture and mobility are significant for protecting spine. The aim was to compare effects of different postural training interventions on spinal posture and mobility. Ninety-six university students (ages: 18–25 years) were allocated into Electrical Stimulation (ES) (n = 24), Exercise (n = 24), Biofeedback Posture Trainer (Backtone) (n = 24), and Postural Education (n = 24, Controls) groups. All the groups got postural education. The interventions were carried out 3 days a week for 8 weeks. Spinal Mouse device (Idiag, Fehraltorf, Switzerland) was used to detect thoracic and lumbar curvatures and mobility (degrees) in standing and sitting positions. Paired Student’s t-test, one-way ANOVA, and pairwise post-hoc tests were used. ES decreased thoracic curvature, the exercise decreased thoracic and lumbar curvature and increased thoracic mobility in standing position between pre-post training (p < 0.05). Exercise and Backtone improved thoracic curvature in sitting (p <0.05). In Exercise Group, thoracic curvature decreased compared to Backtone and Education Groups, and thoracic mobility increased compared to all groups (p < 0.05). The exercise was effective and superior in improving thoracic and lumbar curves, and mobility among university students. ES decreased thoracic curve. Biofeedback posture trainer improved sitting posture. A prospective randomized controlled trial, Level 1.

Physical Therapy for a Child With Infantile Idiopathic Scoliosis and Motor Delay.

PubMed

Hall, Rhea K; Rapport, Mary Jane

2017-07-01

The purpose of this case report is to describe physical therapy (PT) for a child with infantile idiopathic scoliosis and motor delay. A 10-month-old boy with a 28° left thoracolumbar scoliosis was referred for PT and was seen weekly in his home over a 6-month period following a diagnosis of scoliosis and delayed gross motor milestones. Before the initiation of PT, the child was scheduled to undergo serial casting for correction of the spinal curve and was not yet rolling or transitioning in or out of sitting. By the end of the 6-month intervention period, the spinal curve had resolved to 12° without the need for serial casting and the child was walking independently. PT appeared to have a positive effect on reduction of the spinal curve and achievement of gross motor milestones.

Integration of length and curvature in haptic perception.

PubMed

Panday, Virjanand; Tiest, Wouter M Bergmann; Kappers, Astrid M L

2014-01-24

We investigated if and how length and curvature information are integrated when an object is explored in one hand. Subjects were asked to explore four types of objects between thumb and index finger. Objects differed in either length, curvature, both length and curvature correlated as in a circle, or anti-correlated. We found that when both length and curvature are present, performance is significantly better than when only one of the two cues is available. Therefore, we conclude that there is integration of length and curvature. Moreover, if the two cues are correlated in a circular cross-section instead of in an anti-correlated way, performance is better than predicted by a combination of two independent cues. We conclude that integration of curvature and length is highly efficient when the cues in the object are combined as in a circle, which is the most common combination of curvature and length in daily life.

Spinal Instrumentation in Growing Children Retards the Natural Development of Pelvic Incidence.

PubMed

Bekmez, Senol; Demirkiran, Halil Gokhan; Dede, Ozgur; Atici, Yunus; Balioglu, Mehmet Bulent; Kruyt, Moyo; Ward, Timothy; Yazici, Muharrem

2016-09-22

Pelvic incidence increases gradually throughout growth until skeletal maturity. Growing rod instrumentation has been suggested to have a stabilizing effect on the development of the normal sagittal spinal alignment. The purpose of this study is to determine the effect of fixed sagittal plane caused by dual growing rod instrumentation on the natural progression of sagittal spinopelvic parameters in children with idiopathic or idiopathic-like early onset scoliosis. Hospital records of children with growing rod instrumentation from 4 separate institutions were reviewed retrospectively. Inclusion criteria were idiopathic or idiopathic-like early onset scoliosis, treatment with dual growing rods with lower instrumented vertebra L4 or upper and more than 2 years of follow-up. Instrumentation levels, magnitudes of major curve, thoracic kyphosis (T2-T12), lumbar lordosis (L1-S1) and pelvic incidence were recorded from preoperative and postoperative standing whole-spine radiographs. Estimated pelvic incidence was also calculated for each patient as if their spines had not been instrumented using the previous normative data. A total of 37 patients satisfied the inclusion criteria. Average age at initial surgery was 7.4±1.8 years (range, 4 to 12 y). Mean follow-up time was 71±26 months (range, 27 to 120 mo). Mean preoperative Cobb angle of 59±13.5 (range, 30 to 86) degrees was reduced to 35.1±17.5 (range, 11 to 78) degrees at the last follow-up. Mean preoperative T2-T12 kyphosis angle was 46.2±14.9 degrees (range, 22 to 84 degrees). At the latest follow-up, it was 44.8±16.2 degrees (range, 11 to 84 degrees) (P=0.93). Mean L1-S1 lordosis angle was 50.5±10.7 degrees (range, 30 to 72 degrees) preoperatively. At the latest follow-up, mean L1-S1 lordosis angle was 48.8±12.7 degrees (range, 26 to 74 degrees) (P=0.29). Mean preoperative pelvic incidence was 45.7±7.9 degrees (range, 30 to 68 degrees). At the latest follow-up, it was 46.7±8.4 degrees (range, 34 to 72 degrees

Idiopathic Syringomyelia in a Military Helicopter Pilot.

PubMed

Schiemer, Anthony

2017-10-01

A syrinx is a fluid-filled cavity within the spinal cord. They can lead to a variety of symptoms, including limb weakness and back pain. Incidental finding of syringomyelia provides a challenge for clinicians due to the wide variety of possible symptoms. In military aviation, neurological findings in pilots can result in extensive investigation that can lead to potentially invasive management. Conversely, the potential for chronic progression of a spinal syrinx and subsequent neurological deterioration makes early identification critical. Ultimately, the discovery of a lesion may have implications for flying status and operational capability. A 25-yr-old man working as a navy Seahawk helicopter pilot presented with episodes of right arm paraesthesia and pain between the scapulae. On at least one occasion, these symptoms woke him at night. Upon magnetic resonance imaging, dilatation of the central canal in a syrinx-like pattern in the lower cervical region was noted. Neurology review suggested the finding was persistent and unlikely to be responsible for his symptoms. No surgical input was recommended. His symptoms were attributed to mild cervical spondylosis, which resolved with ongoing physiotherapy, and he was returned to flying status. This case highlights several issues involved with the incidental finding of a syringomyelia. Surgical intervention has been known to worsen symptoms. Conversely, studies have identified minimal radiological progression in cases of idiopathic syringomyelia, with fewer individuals displaying neurological deterioration. For aircrew, potentially unnecessary neurosurgical intervention poses risks to a flying career and overall operational capability.Schiemer A. Idiopathic syringomyelia in a military helicopter pilot. Aerosp Med Hum Perform. 2017; 88(10):962-965.

The geometric curvature of the lumbar spine during restricted and unrestricted squats.

PubMed

Hebling Campos, Mário; Furtado Alaman, Laizi I; Seffrin-Neto, Aldo A; Vieira, Carlos A; Costa de Paula, Marcelo; Barbosa de Lira, Claudio A

2017-06-01

The main purpose of this study was to analyze the behavior of the geometric curvature of the lumbar spine during restricted and unrestricted squats, using a novel investigative method. The rationale for our hypothesis is that the lumbar curvature has different patterns at different spine levels depending on the squat technique used. Spine motion was collected via stereo-photogrammetric analysis in nineteen participants (11 males, 8 females). The reconstructed spine points at the upright neutral position and at the deepest position of the squat exercise were projected onto the sagittal plane of the trunk, a polynomial was fitted to the data, and were quantified the two-dimensional geometric curvature at lower, central and higher lumbar levels, besides the inclination of trunk and lumbosacral region, the overall geometric curvature and overall angle of the lumbar spine. The mean values for each variable were analysed with paired t-test (P<0.05). The lumbar presents a flexion from upright neutral posture to deepest point of the movement, but for the lower lumbar the flexion is less intense if the knees travel anteriorly past the toes. The trunk and the lumbosacral region lean forward in both squat techniques and these effects are also reduced in unrestricted squats. The data collected in the study are evidence that during barbell squats the lumbar curvature has different patterns at different spinal levels depending on the exercise technique. The lower lumbar spine appears to be less overloaded during unrestricted squats.

Automated quasi-3D spine curvature quantification and classification

NASA Astrophysics Data System (ADS)

Khilari, Rupal; Puchin, Juris; Okada, Kazunori

2018-02-01

Scoliosis is a highly prevalent spine deformity that has traditionally been diagnosed through measurement of the Cobb angle on radiographs. More recent technology such as the commercial EOS imaging system, although more accurate, also require manual intervention for selecting the extremes of the vertebrae forming the Cobb angle. This results in a high degree of inter and intra observer error in determining the extent of spine deformity. Our primary focus is to eliminate the need for manual intervention by robustly quantifying the curvature of the spine in three dimensions, making it consistent across multiple observers. Given the vertebrae centroids, the proposed Vertebrae Sequence Angle (VSA) estimation and segmentation algorithm finds the largest angle between consecutive pairs of centroids within multiple inflection points on the curve. To exploit existing clinical diagnostic standards, the algorithm uses a quasi-3-dimensional approach considering the curvature in the coronal and sagittal projection planes of the spine. Experiments were performed with manuallyannotated ground-truth classification of publicly available, centroid-annotated CT spine datasets. This was compared with the results obtained from manual Cobb and Centroid angle estimation methods. Using the VSA, we then automatically classify the occurrence and the severity of spine curvature based on Lenke's classification for idiopathic scoliosis. We observe that the results appear promising with a scoliotic angle lying within +/- 9° of the Cobb and Centroid angle, and vertebrae positions differing by at the most one position. Our system also resulted in perfect classification of scoliotic from healthy spines with our dataset with six cases.

Female patients' and parents' assessment of deformity- and brace-related stress in the conservative treatment of adolescent idiopathic scoliosis.

PubMed

Misterska, Ewa; Glowacki, Maciej; Latuszewska, Joanna

2012-06-15

A cross-sectional analysis of parents' and patients' perceptions of deformity- and brace-related stress regarding conservative treatment of adolescent idiopathic scoliosis. The purpose of this study was to determine the agreement between patients' and parents' assessments of emotional stress and to compare these assessments with radiographical measurements of spinal deformity. Conservative treatment in patients with scoliosis may cause emotional stress. To our knowledge, no group has ever reported patient and parental estimation of stress related to wearing a brace and spinal deformity in girls with adolescent idiopathic scoliosis. Sixty-three pairs of parents and girls with adolescent idiopathic scoliosis treated with a Cheneau brace were separately asked to complete the Bad Sobberheim Stress Questionnaire-Deformity and the Bad Sobberheim Stress Questionnaire-Brace. The age range of the patients was from 10 to 17 years. Patients were assessed at a mean of 14.12 (SD, 10.99) months after the start of the conservative treatment. Patients thought that a moderate level of stress was connected with conservative treatment; however, the stress level, related to perceived trunk deformation, was low. From the parents' perspective, patients experienced a moderate level of stress during conservative treatment and related to spinal deformity. The study groups differ in their perception of stress levels due to body disfigurement but not during the conservative treatment. Parent-patient stress-level disparities were not related to body mass index, age of the patient, brace application, and radiographical measurements of spinal deformity. Patients and parents perceive the emotional stress related to brace treatment in the same way; however, parents overestimate the assessment of stress levels related to body deformity. From the perspective of patients and parents, brace wearing increased the level of stress induced by the deformity alone. Complete assessment of conservative

Berry curvature dipole in Weyl semimetal materials: An ab initio study

NASA Astrophysics Data System (ADS)

Zhang, Yang; Sun, Yan; Yan, Binghai

2018-01-01

Noncentrosymmetric metals are anticipated to exhibit a dc photocurrent in the nonlinear optical response caused by the Berry curvature dipole in momentum space. Weyl semimetals (WSMs) are expected to be excellent candidates for observing these nonlinear effects because they carry a large Berry curvature concentrated in small regions, i.e., near the Weyl points. We have implemented the semiclassical Berry curvature dipole formalism into an ab initio scheme and investigated the second-order nonlinear response for two representative groups of materials: the TaAs-family type-I WSMs and the MoTe2-family type-II WSMs. Both types of WSMs exhibited a Berry curvature dipole in which type-II Weyl points are usually superior to the type-I WSM because of the strong tilt. Corresponding nonlinear susceptibilities in several materials promise a nonlinear Hall effect in the dc field limit, which is within the experimentally detectable range.

Narcolepsy Type 1 and Idiopathic Generalized Epilepsy: Diagnostic and Therapeutic Challenges in Dual Cases.

PubMed

Baiardi, Simone; Vandi, Stefano; Pizza, Fabio; Alvisi, Lara; Toscani, Lucia; Zambrelli, Elena; Tinuper, Paolo; Mayer, Geert; Plazzi, Giuseppe

2015-11-15

The aim of this study is to describe the possible co-occurrence of narcolepsy type 1 and generalized epilepsy, focusing on diagnostic challenge and safety of dual treatments. Four patients with comorbidity for narcolepsy type 1 and idiopathic generalized epilepsy are reported: in three cases the onset of epilepsy preceded narcolepsy type 1 appearance, whereas in one case epileptic spells onset was subsequent. Patients presented with absences, myoclonic and tonic-clonic seizure type: in the patient with tonic-clonic seizures the dual pathology was easily recognized, in the other cases the first diagnosis caused the comorbid disease to be overlooked, independent of the time-course sequence. All four patients underwent neurological examination, video-electroencephalogram during which ictal and interictal epileptic discharges were recorded, and sleep polysomnographic studies. Repeated sleep onset rapid eye movement periods (SOREMPs) were documented with the multiple sleep latency test (MLST) in all the four cases. All patients had unremarkable brain magnetic resonance imaging studies and cerebrospinal hypocretin-1 was assessed in two patients, revealing undetectable levels. The association of antiepileptic drugs and substances currently used to treat narcolepsy type 1, including sodium oxybate, was effective in improving seizures, sleep disturbance, and cataplexy. Narcolepsy type 1 may occur in association with idiopathic generalized epilepsy, leading to remarkable diagnostic and therapeutic challenges. Electrophysiological studies as well as a comprehensive somnologic interview can help confirm the diagnosis in patients with ambiguous neurological history. Sodium oxybate in combination with antiepileptic drugs is safe and effective in treating cataplexy and excessive daytime sleepiness. © 2015 American Academy of Sleep Medicine.

The Influence of the "Straighten Your Back" Command on the Sagittal Spinal Curvatures in Children with Generalized Joint Hypermobility.

PubMed

Czaprowski, Dariusz; Pawłowska, Paulina; Kolwicz-Gańko, Aleksandra; Sitarski, Dominik; Kędra, Agnieszka

2017-01-01

Objectives . The aim of the study was to assess the change of sagittal spinal curvatures in children with generalized joint hypermobility (GJH) instructed with "straighten your back" command (SYB). Methods . The study included 56 children with GJH. The control group consisted of 193 children. Sacral slope (SS), lumbar lordosis (LL), global thoracic kyphosis (TK), lower thoracic kyphosis (LK), and upper thoracic kyphosis (UK) were assessed with Saunders inclinometer both in spontaneous positions (standing and sitting) and after the SYB. Results . Children with GJH after SYB presented the following: in standing, increase in SS and decrease in TK, LK, and UK ( P < 0.01), with LL not significantly changed; in sitting: decrease in global thoracic kyphosis (35.5° (SD 20.5) versus 21.0° (SD 15.5), P < 0.001) below the standards proposed in the literature (30-40°) and flattening of its lower part ( P < 0.001). The same changes were observed in the control group. Conclusions . In children with generalized joint hypermobility, the "straighten your back" command leads to excessive reduction of the global thoracic kyphosis and flattening of its lower part. Therefore, the "straighten your back" command should not be used to achieve the optimal standing and sitting positions.

Spinal Muscular Atrophy With Respiratory Distress Type 1-A Child With Atypical Presentation.

PubMed

Chiu, Annie Ting Gee; Chan, Sophelia Hoi Shan; Wu, Shun Ping; Ting, Shun Hin; Chung, Brian Hon Yin; Chan, Angel On Kei; Wong, Virginia Chun Nei

2018-01-01

The authors report a child with spinal muscular atrophy with respiratory distress type 1 (SMARD1). She presented atypically with hypothyroidism and heart failure due to septal defects that required early heart surgery and microcephaly in association with cerebral atrophy and thin corpus collosum. The subsequent asymmetrical onset of diaphragmatic paralysis, persistent hypotonia, and generalized muscle weakness led to the suspicion of spinal muscular atrophy with respiratory distress type 1. Sanger sequencing confirmed a compound heterozygous mutation in the Immunoglobulin Mu Binding Protein 2 (IGHMBP2) gene, with a known mutation c.2362C > T (p.Arg788*) and a novel frameshift mutation c.2048delG (p.Gly683A1afs*50). Serial nerve conduction study and electromyography confirmed progressive sensorimotor polyneuropathy and neuronopathy. In summary, this case report describes a child with spinal muscular atrophy with respiratory distress type 1 also with congenital cardiac disease and endocrine dysfunction, expanding the phenotypic spectrum of this condition. A high index of suspicion is needed in diagnosing this rare condition to guide the management and genetic counseling.

Active self-correction of spinal posture in pain-free women in response to the command "straighten your back".

PubMed

Barczyk-Pawelec, Katarzyna; Sipko, Tomasz

2017-10-01

Evidence is limited regarding the regional changes in spinal posture after self-correction. The aim of the present study was to evaluate whether active self-correction improved standing and sitting spinal posture. Photogrammetry was used to assess regional spinal curvatures and vertical global spine orientation (GSO) in 42 asymptotic women aged 20-24 years. Upper thoracic spine angle and GSO increased in response to self-correction, while the thoracolumbar and lumbosacral angles decreased. Self-correction in the standing position resulted in decreased inclination of the upper thoracic and thoracolumbar spinal angles. Correction of sitting posture reduced the angle of the upper thoracic spine and GSO. The effects of active self-correction on spinal curvature and GSO were different for the standing versus sitting position; the greatest effects of active correction were noted in the thoracic spine. Balanced and lordotic postures were most prevalent in the habitual and actively self-corrected standing positions, whereas the kyphotic posture was most prevalent in the habitual sitting position, indicative that self-correction back posture in the standing position could be an important health-related daily activity, especially during prolonged sitting.

Treatment of nonneovascular idiopathic macular telangiectasia type 2 with intravitreal ranibizumab: results of a phase II clinical trial.

PubMed

Toy, Brian C; Koo, Euna; Cukras, Catherine; Meyerle, Catherine B; Chew, Emily Y; Wong, Wai T

2012-05-01

To evaluate the safety and preliminary efficacy of intravitreal ranibizumab for nonneovascular idiopathic macular telangiectasia Type 2. Single-center, open-label Phase II clinical trial enrolling five participants with bilateral nonneovascular idiopathic macular telangiectasia Type 2. Intravitreal ranibizumab (0.5 mg) was administered every 4 weeks in the study eye for 12 months with the contralateral eye observed. Outcome measures included changes in best-corrected visual acuity, area of late-phase leakage on fluorescein angiography, and retinal thickness on optical coherence tomography. The study treatment was well tolerated and associated with few adverse events. Change in best-corrected visual acuity at 12 months was not significantly different between treated study eyes (0.0 ± 7.5 letters) and control fellow eyes (+2.2 ± 1.9 letters). However, decreases in the area of late-phase fluorescein angiography leakage (-33 ± 20% for study eyes, +1 ± 8% for fellow eyes) and in optical coherence tomography central subfield retinal thickness (-11.7 ± 7.0% for study eyes and -2.9 ± 3.5% for fellow eyes) were greater in study eyes compared with fellow eyes. Despite significant anatomical responses to treatment, functional improvement in visual acuity was not detected. Intravitreal ranibizumab administered monthly over a time course of 12 months is unlikely to provide a general and significant benefit to patients with nonneovascular idiopathic macular telangiectasia Type 2.

Understanding physical activity participation in spinal cord injured populations: Three narrative types for consideration

PubMed Central

Papathomas, Anthony; Williams, Toni L.; Smith, Brett

2015-01-01

The aim of this study was to identity the types of physical activity narratives drawn upon by active spinal injured people. More than 50 h of semi-structured life-story interview data, collected as part of larger interdisciplinary program of disability lifestyle research, was analysed for 30 physically active male and female spinal cord injury (SCI) participants. A structural narrative analysis of data identified three narrative types which people with SCI draw on: (1) exercise is restitution, (2) exercise is medicine, and (3) exercise is progressive redemption. These insights contribute new knowledge by adding a unique narrative perspective to existing cognitive understanding of physical activity behaviour in the spinal cord injured population. The implications of this narrative typology for developing effective positive behavioural change interventions are critically discussed. It is concluded that the identified narratives types may be constitutive, as well as reflective, of physical activity experiences and therefore may be a useful tool on which to base physical activity promotion initiatives. PMID:26282868

On the Weyl curvature hypothesis

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

Stoica, Ovidiu Cristinel, E-mail: holotronix@gmail.com

2013-11-15

The Weyl curvature hypothesis of Penrose attempts to explain the high homogeneity and isotropy, and the very low entropy of the early universe, by conjecturing the vanishing of the Weyl tensor at the Big-Bang singularity. In previous papers it has been proposed an equivalent form of Einstein’s equation, which extends it and remains valid at an important class of singularities (including in particular the Schwarzschild, FLRW, and isotropic singularities). Here it is shown that if the Big-Bang singularity is from this class, it also satisfies the Weyl curvature hypothesis. As an application, we study a very general example of cosmologicalmore » models, which generalizes the FLRW model by dropping the isotropy and homogeneity constraints. This model also generalizes isotropic singularities, and a class of singularities occurring in Bianchi cosmologies. We show that the Big-Bang singularity of this model is of the type under consideration, and satisfies therefore the Weyl curvature hypothesis. -- Highlights: •The singularities we introduce are described by finite geometric/physical objects. •Our singularities have smooth Riemann and Weyl curvatures. •We show they satisfy Penrose’s Weyl curvature hypothesis (Weyl=0 at singularities). •Examples: FLRW, isotropic singularities, an extension of Schwarzschild’s metric. •Example: a large class of singularities which may be anisotropic and inhomogeneous.« less

Early changes in somatosensory function in spinal pain: a systematic review and meta-analysis.

PubMed

Marcuzzi, Anna; Dean, Catherine M; Wrigley, Paul J; Hush, Julia M

2015-02-01

Alterations in sensory processing have been demonstrated in chronic low back and neck pain. However, it has not been yet systematically summarized how early these changes occur in spinal pain. This systematic review examines the available literature measuring somatosensory function in acute (<6 weeks) and subacute (6-12 weeks) spinal pain. The protocol for this review has been registered on the International Prospective Register of Systematic Reviews (PROSPERO). An electronic search of 4 databases was conducted to retrieve studies assessing somatosensory function by quantitative sensory testing in adults with spinal pain of up to 12 weeks duration. Two reviewers independently screened the studies and assessed the risk of bias. Studies were grouped according to spinal pain condition (whiplash injury, idiopathic neck pain, and nonspecific low back pain), and, where possible, meta-analyses were performed for comparable results. Fifteen studies were included. Sources of bias included lack of assessor blinding, unclear sampling methods, and lack of control for confounders. We found that: (1) there is consistent evidence for thermal and widespread mechanical pain hypersensitivity in the acute stage of whiplash, (2) there is no evidence for pain hypersensitivity in the acute and subacute stage of idiopathic neck pain, although the body of evidence is small, and (3) hyperalgesia and spinal cord hyperexcitability have been detected in early stages of nonspecific low back pain, although evidence about widespread effects are conflicting. Future longitudinal research using multiple sensory modalities and standardized testing may reveal the involvement of somatosensory changes in the development and maintenance of chronic pain.

Gaussian curvature directs the distribution of spontaneous curvature on bilayer membrane necks.

PubMed

Chabanon, Morgan; Rangamani, Padmini

2018-03-28

Formation of membrane necks is crucial for fission and fusion in lipid bilayers. In this work, we seek to answer the following fundamental question: what is the relationship between protein-induced spontaneous mean curvature and the Gaussian curvature at a membrane neck? Using an augmented Helfrich model for lipid bilayers to include membrane-protein interaction, we solve the shape equation on catenoids to find the field of spontaneous curvature that satisfies mechanical equilibrium of membrane necks. In this case, the shape equation reduces to a variable coefficient Helmholtz equation for spontaneous curvature, where the source term is proportional to the Gaussian curvature. We show how this latter quantity is responsible for non-uniform distribution of spontaneous curvature in minimal surfaces. We then explore the energetics of catenoids with different spontaneous curvature boundary conditions and geometric asymmetries to show how heterogeneities in spontaneous curvature distribution can couple with Gaussian curvature to result in membrane necks of different geometries.

Spinal deformity in children treated for neuroblastoma

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

Mayfield, J.K.; Riseborough, E.J.; Jaffe, N.

1981-02-01

Of seventy-four children who were treated at a mean age of seventeen months for neuroblastoma and survived more than five years, fifty-six had spinal deformity due either to the disease or to the treatment after a mean follow-up of 12.9 years. Of these fifty-six, 50 per cent had post-radiation scoliosis, and 16 per cent had post-radiation kyphosis, most frequently at the thoracolumbar junction, at the time of follow-up. Two kyphotic thoracolumbar curve patterns were identified: an angular kyphosis with a short radius of curvature and its apex at the twelfth thoracic and first lumbar vertebrae, and a thoracic kyphosis withmore » a long radius of curvature that extended into the lumbar spine. The post-radiation deformity - both the scoliosis and the kyphosis - progressed with growth, the scoliosis at a rate of 1 degree per year and the kyphosis at a rate of 3 degrees per year. Epidural spread of the neuroblastoma was associated with most of the cases of severe scoliosis and kyphosis. The deformity was due either to the laminectomy or to the paraplegia acting in conjunction with the radiation. Eighteen per cent of 419 children with this malignant disease survived more than five years, and of the survivors, 20 per cent had spinal deformity severe enough to warrant treatment. The factors associated with the development of spinal deformity in patient treated for neuroblastoma were: orthovoltage radiation exceeding 3000 rads, asymmetrical radiation of the spine, thoracolumbar kyphosis, and epidural spread of the tumor.« less

Idiopathic scoliosis: the tethered spine II: post-surgical pain.

PubMed

Whyte Ferguson, Lucy

2014-10-01

The treatment of severe chronic pain in young people following surgery for the correction of curvatures of idiopathic scoliosis (IS) is presented through two case histories. Effective treatment involved release of myofascial trigger points (TrPs) known to refer pain into the spine, and treatment of related fascia and joint dysfunction. The TrPs found to be contributing to spinal area pain were located in muscles at some distance from the spine rather than in the paraspinal muscles. Referred pain from these TrPs apparently accounted for pain throughout the base of the neck and thoracolumbar spine. Exploratory surgery was considered for one patient to address pain following rod placement but the second surgery became unnecessary when the pain was controlled with treatment of the myofascial pain and joint dysfunction. The other individual had both scoliosis and hyperkyphosis, had undergone primary scoliosis surgery, and subsequently underwent a second surgery to remove hardware in an attempt to address her persistent pain following the initial surgery (and because of dislodged screws). The second surgery did not, however, reduce her pain. In both cases these individuals, with severe chronic pain following scoliosis corrective surgery, experienced a marked decrease of pain after myofascial treatment. As will be discussed below, despite the fact that a significant minority of individuals who have scoliosis corrective surgery are thought to require a second surgery, and despite the fact that pain is the most common reason leading to such revision surgery, myofascial pain syndrome (MPS) had apparently not previously been considered as a possible factor in their pain. Copyright © 2014 Elsevier Ltd. All rights reserved.

Locomotor skills and balance strategies in adolescents idiopathic scoliosis.

PubMed

Mallau, Sophie; Bollini, Gérard; Jouve, Jean-Luc; Assaiante, Christine

2007-01-01

Locomotor balance control assessment was performed to study the effect of idiopathic scoliosis on head-trunk coordination in 17 patients with adolescent idiopathic scoliosis (AIS) and 16 control subjects. The aim of this study was to explore the functional effects of structural spinal deformations like idiopathic scoliosis on the balance strategies used during locomotion. Up to now, the repercussion of the idiopathic scoliosis on head-trunk coordination and balance strategies during locomotion is relatively unknown. Seventeen patients with AIS (mean age 14 years 3 months, 10 degrees < Cobb angle > 30 degrees) and 16 control subjects (mean age 14 years 1 month) were tested during various locomotor tasks: walking on the ground, walking on a line, and walking on a beam. Balance control was examined in terms of rotation about the vertical axis (yaw) and on a frontal plane (roll). Kinematics of foot, pelvis, trunk, shoulder, and head rotations were measured with an automatic optical TV image processor in order to calculate angular dispersions and segmental stabilizations. Decreasing the walking speed is the main adaptive strategy used in response to balance problems in control subjects as well as patients with AIS. However, patients with AIS performed walking tasks more slowly than normal subjects (around 15%). Moreover, the pelvic stabilization is preserved, despite the structural changes affecting the spine. Lastly, the biomechanical defect resulting from idiopathic scoliosis mainly affects the yaw head stabilization during locomotion. Patients with AIS show substantial similarities with control subjects in adaptive strategies relative to locomotor velocity as well as balance control based on segmental stabilization. In contrast, the loss of the yaw head stabilization strategies, mainly based on the use of vestibular information, probably reflects the presence of vestibular deficits in the patients with AIS.

The Influence of the “Straighten Your Back” Command on the Sagittal Spinal Curvatures in Children with Generalized Joint Hypermobility

PubMed Central

Pawłowska, Paulina; Kolwicz-Gańko, Aleksandra; Sitarski, Dominik

2017-01-01

Objectives. The aim of the study was to assess the change of sagittal spinal curvatures in children with generalized joint hypermobility (GJH) instructed with “straighten your back” command (SYB). Methods. The study included 56 children with GJH. The control group consisted of 193 children. Sacral slope (SS), lumbar lordosis (LL), global thoracic kyphosis (TK), lower thoracic kyphosis (LK), and upper thoracic kyphosis (UK) were assessed with Saunders inclinometer both in spontaneous positions (standing and sitting) and after the SYB. Results. Children with GJH after SYB presented the following: in standing, increase in SS and decrease in TK, LK, and UK (P < 0.01), with LL not significantly changed; in sitting: decrease in global thoracic kyphosis (35.5° (SD 20.5) versus 21.0° (SD 15.5), P < 0.001) below the standards proposed in the literature (30–40°) and flattening of its lower part (P < 0.001). The same changes were observed in the control group. Conclusions. In children with generalized joint hypermobility, the “straighten your back” command leads to excessive reduction of the global thoracic kyphosis and flattening of its lower part. Therefore, the “straighten your back” command should not be used to achieve the optimal standing and sitting positions. PMID:28116313

Entire radial solutions of elliptic systems and inequalities of the mean curvature type

NASA Astrophysics Data System (ADS)

Filippucci, Roberta

2007-10-01

In this paper we study first nonexistence of radial entire solutions of elliptic systems of the mean curvature type with a singular or degenerate diffusion depending on the solution u. In particular we extend a previous result given in [R. Filippucci, Nonexistence of radial entire solutions of elliptic systems, J. Differential Equations 188 (2003) 353-389]. Moreover, in the scalar case we obtain nonexistence of all entire solutions, radial or not, of differential inequalities involving again operators of the mean curvature type and a diffusion term. We prove that in the scalar case, nonexistence of entire solutions is due to the explosion of the derivative of every nonglobal radial solution in the right extremum of the maximal interval of existence, while in that point the solution is bounded. This behavior is qualitatively different with respect to what happens for the m-Laplacian operator, studied in [R. Filippucci, Nonexistence of radial entire solutions of elliptic systems, J. Differential Equations 188 (2003) 353-389], where nonexistence of entire solutions is due, even in the vectorial case, to the explosion in norm of the solution at a finite point. Our nonexistence theorems for inequalities extend previous results given by Naito and Usami in [YE Naito, H. Usami, Entire solutions of the inequality div(A(=u)=u)[greater-or-equal, slanted]f(u), Math. Z. 225 (1997) 167-175] and Ghergu and Radulescu in [M. Ghergu, V. Radulescu, Existence and nonexistence of entire solutions to the logistic differential equation, Abstr. Appl. Anal. 17 (2003) 995-1003].

Spinal cord herniation following cervical meningioma excision: a rare clinical entity and review of literature.

PubMed

Aiyer, Siddharth N; Shetty, Ajoy Prasad; Kanna, Rishi; Maheswaran, Anupama; Rajasekaran, S

2016-05-01

Spinal cord herniation following surgery is an extremely uncommon clinical condition with very few reports in published literature. This condition usually occurs as a spontaneous idiopathic phenomenon often in the thoracic spine or following a scenario of post traumatic spinal cord/nerve root injury. Rarely has it been reported following spinal cord tumor surgery. To document a case of cervical spinal cord herniation as a late onset complication following spinal cord tumor surgery with an atypical presentation of monoparesis. Case report. We describe the clinical presentation, operative procedure, post operative outcome and review of literature of this rare clinical condition. A 57-year-old man presented with right upper limb monoparesis due to a spinal cord herniation 6 years after a cervical intradural meningioma excision. The patients underwent surgery to reduce the herniation and duroplasty with subsequent complete resolution of symptoms. Spinal cord herniation must be considered as differential diagnosis in scenarios of spinal cord tumor excision presenting with late onset neurological deficit. These cases may present as paraparesis, Brown-sequard syndrome and rarely as in our case as monoparesis.

Negative Gaussian curvature induces significant suppression of thermal conduction in carbon crystals.

PubMed

Zhang, Zhongwei; Chen, Jie; Li, Baowen

2017-09-28

From the mathematic category of surface Gaussian curvature, carbon allotropes can be classified into three types: zero curvature, positive curvature, and negative curvature. By performing Green-Kubo equilibrium molecular dynamics simulations, we found that surface curvature has a significant impact on the phonon vibration and thermal conductivity (κ) of carbon crystals. When curving from zero curvature to negative or positive curvature structures, κ is reduced by several orders of magnitude. Interestingly, we found that κ of negatively curved carbon crystals exhibits a monotonic dependence on curvature. Through phonon mode analysis, we show that curvature induces remarkable phonon softening in phonon dispersion, which results in the reduction of phonon group velocity and flattening of phonon band structure. Furthermore, the curvature was found to induce phonon mode hybridization, leading to the suppression of phonon relaxation time. Our study provides physical insight into thermal transport in curvature materials, and will be valuable in the modulation of phonon activity through surface curvature.

Impact of membrane curvature on amyloid aggregation.

PubMed

Terakawa, Mayu S; Lin, Yuxi; Kinoshita, Misaki; Kanemura, Shingo; Itoh, Dai; Sugiki, Toshihiko; Okumura, Masaki; Ramamoorthy, Ayyalusamy; Lee, Young-Ho

2018-04-28

The misfolding, amyloid aggregation, and fibril formation of intrinsically disordered proteins/peptides (or amyloid proteins) have been shown to cause a number of disorders. The underlying mechanisms of amyloid fibrillation and structural properties of amyloidogenic precursors, intermediates, and amyloid fibrils have been elucidated in detail; however, in-depth examinations on physiologically relevant contributing factors that induce amyloidogenesis and lead to cell death remain challenging. A large number of studies have attempted to characterize the roles of biomembranes on protein aggregation and membrane-mediated cell death by designing various membrane components, such as gangliosides, cholesterol, and other lipid compositions, and by using various membrane mimetics, including liposomes, bicelles, and different types of lipid-nanodiscs. We herein review the dynamic effects of membrane curvature on amyloid generation and the inhibition of amyloidogenic proteins and peptides, and also discuss how amyloid formation affects membrane curvature and integrity, which are key for understanding relationships with cell death. Small unilamellar vesicles with high curvature and large unilamellar vesicles with low curvature have been demonstrated to exhibit different capabilities to induce the nucleation, amyloid formation, and inhibition of amyloid-β peptides and α-synuclein. Polymorphic amyloidogenesis in small unilamellar vesicles was revealed and may be viewed as one of the generic properties of interprotein interaction-dominated amyloid formation. Several mechanical models and phase diagrams are comprehensively shown to better explain experimental findings. The negative membrane curvature-mediated mechanisms responsible for the toxicity of pancreatic β cells by the amyloid aggregation of human islet amyloid polypeptide (IAPP) and binding of the precursors of the semen-derived enhancer of viral infection (SEVI) are also described. The curvature-dependent binding

Idiopathic ophthalmodynia and idiopathic rhinalgia: two topographic facial pain syndromes.

PubMed

Pareja, Juan A; Cuadrado, María L; Porta-Etessam, Jesús; Fernández-de-las-Peñas, César; Gili, Pablo; Caminero, Ana B; Cebrián, José L

2010-09-01

To describe 2 topographic facial pain conditions with the pain clearly localized in the eye (idiopathic ophthalmodynia) or in the nose (idiopathic rhinalgia), and to propose their distinction from persistent idiopathic facial pain. Persistent idiopathic facial pain, burning mouth syndrome, atypical odontalgia, and facial arthromyalgia are idiopathic facial pain syndromes that have been separated according to topographical criteria. Still, some other facial pain syndromes might have been veiled under the broad term of persistent idiopathic facial pain. Through a 10-year period we have studied all patients referred to our neurological clinic because of facial pain of unknown etiology that might deviate from all well-characterized facial pain syndromes. In a group of patients we have identified 2 consistent clinical pictures with pain precisely located either in the eye (n=11) or in the nose (n=7). Clinical features resembled those of other localized idiopathic facial syndromes, the key differences relying on the topographic distribution of the pain. Both idiopathic ophthalmodynia and idiopathic rhinalgia seem specific pain syndromes with a distinctive location, and may deserve a nosologic status just as other focal pain syndromes of the face. Whether all such focal syndromes are topographic variants of persistent idiopathic facial pain or independent disorders remains a controversial issue.

Topologically preserving straightening of spinal cord MRI.

PubMed

De Leener, Benjamin; Mangeat, Gabriel; Dupont, Sara; Martin, Allan R; Callot, Virginie; Stikov, Nikola; Fehlings, Michael G; Cohen-Adad, Julien

2017-10-01

To propose a robust and accurate method for straightening magnetic resonance (MR) images of the spinal cord, based on spinal cord segmentation, that preserves spinal cord topology and that works for any MRI contrast, in a context of spinal cord template-based analysis. The spinal cord curvature was computed using an iterative Non-Uniform Rational B-Spline (NURBS) approximation. Forward and inverse deformation fields for straightening were computed by solving analytically the straightening equations for each image voxel. Computational speed-up was accomplished by solving all voxel equation systems as one single system. Straightening accuracy (mean and maximum distance from straight line), computational time, and robustness to spinal cord length was evaluated using the proposed and the standard straightening method (label-based spline deformation) on 3T T 2 - and T 1 -weighted images from 57 healthy subjects and 33 patients with spinal cord compression due to degenerative cervical myelopathy (DCM). The proposed algorithm was more accurate, more robust, and faster than the standard method (mean distance = 0.80 vs. 0.83 mm, maximum distance = 1.49 vs. 1.78 mm, time = 71 vs. 174 sec for the healthy population and mean distance = 0.65 vs. 0.68 mm, maximum distance = 1.28 vs. 1.55 mm, time = 32 vs. 60 sec for the DCM population). A novel image straightening method that enables template-based analysis of quantitative spinal cord MRI data is introduced. This algorithm works for any MRI contrast and was validated on healthy and patient populations. The presented method is implemented in the Spinal Cord Toolbox, an open-source software for processing spinal cord MRI data. 1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2017;46:1209-1219. © 2017 International Society for Magnetic Resonance in Medicine.

Spinal Muscular Atrophy Type I: Is It Ethical to Standardize Supportive Care Intervention in Clinical Trials?

PubMed

Finkel, Richard S; Bishop, Kathie M; Nelson, Robert M

2017-02-01

The natural history of spinal muscular atrophy type I (SMA-I) has changed as improved medical support has become available. With investigational drugs for spinal muscular atrophy now in clinical trials, efficient trial design focuses on enrolling recently diagnosed infants, providing best available supportive care, and minimizing subject variation. The quandary has arisen whether it is ethically appropriate to specify a predefined level of nutritional and/or ventilation support for spinal muscular atrophy type I subjects while participating in these studies. We conducted a survey at 2 spinal muscular atrophy investigator meetings involving physician investigators, clinical evaluators, and study coordinators from North America, Europe, and Asia-Pacific. Each group endorsed the concept that having a predefined degree of nutritional and ventilation support was warranted in this context. We discuss how autonomy, beneficence/non-maleficence, noncoercion, social benefit, and equipoise can be maintained when a predefined level of supportive care is proposed, for participation in a clinical trial.

Comparison of the scoliosis curve patterns and MRI syrinx cord characteristics of idiopathic syringomyelia versus Chiari I malformation.

PubMed

Zhu, Zezhang; Sha, Shifu; Chu, Winnie C C; Yan, Huang; Xie, Dingding; Liu, Zhen; Sun, Xu; Zhu, Weiguo; Cheng, Jack C Y; Qiu, Yong

2016-02-01

Although the more readily available MR imaging has brought about more incidental findings of idiopathic syringomyelia (IS), no published study has specifically addressed the clinical and imaging features of IS-associated scoliosis. Since IS and Chiari I malformation (CMI)-type syringomyelia are hypothesized to share a common underlying developmental pathomechanism, this study aimed to investigate the scoliosis curve patterns and MRI syrinx cord characteristics of patients with IS comparing with those seen in CMI. Sixty-one patients with scoliosis secondary to IS were identified and reviewed retrospectively. The curve pattern and specific curve features were recorded and compared with historic CMI controls. Location, size, and morphological appearance of the syrinx were systematically assessed on MR images. The maximal syrinx/cord ratio and rostrocaudal length of the syrinx in IS averaged 0.43 ± 0.16 (range 0.17-0.78) and 4.6 ± 2.5 (range 2-15) vertebral levels, respectively, both of which were smaller than those reported in CMI-type syringomyelia. Regarding the characteristics of IS-related scoliosis, sagittal profiles as well as the frequency of curve patterns and atypical features were all found to resemble those in patients with CMI (P > .05). Among the 47 individuals with a single thoracic curve, Fisher exact test revealed a significant correlation between curve convexity and the dominant side of deviated syrinx (83.3 % concordance rate, P = .021). In addition, apex of the thoracic curve trended toward being significantly correlated with the level of maximum expansion of the syrinx (P = .066). Radiological characteristics of scoliosis were found to be similar between idiopathic and CMI-type syrinx in both the coronal and sagittal planes, adding further evidence to the concept that these entities may be part of a spectrum of disease sharing a common pathophysiological mechanism. The thoracic spine in IS patients tended to be convex to the deviated side of

Spinal Stenosis

MedlinePlus

... Overview Spinal stenosis is a narrowing of the spaces within your spine, which can put pressure on ... stenosis, doctors may recommend surgery to create additional space for the spinal cord or nerves. Types of ...

Exercises for adolescent idiopathic scoliosis: a Cochrane systematic review.

PubMed

Romano, Michele; Minozzi, Silvia; Zaina, Fabio; Saltikov, Josette Bettany; Chockalingam, Nachiappan; Kotwicki, Tomasz; Hennes, Axel Maier; Negrini, Stefano

2013-06-15

Systematic review of interventions. To evaluate the efficacy of scoliosis-specific exercise (SSE) in adolescent patients with adolescent idiopathic scoliosis (AIS). AIS is a 3-dimensional deformity of the spine. Although AIS can progress during growth and cause a surface deformity, it is usually not symptomatic. However, in adulthood, if the final spinal curvature surpasses a certain critical threshold, the risk of health problems and curve progression is increased. The use of SSEs to reduce progression of AIS and postpone or avoid other more invasive treatments is controversial. The following databases (up to March 30, 2011) were searched with no language limitations: CENTRAL (The Cochrane Library 2011, issue 2), MEDLINE (from January 1966), EMBASE (from January 1980), CINHAL (from January 1982), SPORTDiscus (from January 1975), PsycINFO (from January 1887), and PEDro (from January 1929). We screened reference lists of articles and conducted an extensive hand search of gray literature. randomized controlled trials and prospective cohort studies with a control group comparing exercises with no treatment, other treatment, surgery, and different types of exercises. Two review authors independently selected studies, assessed risk of bias and extracted data. Two studies (154 participants) were included. There is low-quality evidence from 1 randomized controlled study that exercises as an adjunctive to other conservative treatments to increase the efficacy of these treatments (thoracic curve reduced: mean difference 9.00, [95% confidence interval, 5.47-12.53]; lumbar curve reduced: mean difference 8.00, [95% confidence interval, 5.08-10.92]). There is very low-quality evidence from a prospective controlled cohort study that SSEs structured within an exercise program can reduce brace prescription (risk ratio, 0.24; [95% confidence interval, 0.06-1.04]) as compared with "usual physiotherapy" [many different kinds of general exercises according to the preferences of the

Diffuse idiopathic skeletal hyperostosis from Roman Hungary.

PubMed

Hlavenková, Lucia; Gábor, Olivér; Benus, Radoslav; Smrcka, Václav; Jambor, Jaroslav; Hajdu, Tamás

2013-01-01

This paper deals with cases of diffuse idiopathic skeletal hyperostosis (DISH) found at the Late Roman Age necropolis in Pécs, Hungary (4th century AD). The skeletal remains of two male individuals, aged between 60-70 years and 45-55 years, displayed right-sided ossification of the anterior longitudinal ligament with extra-spinal manifestations typical in DISH cases. It is presumed that both male individuals were middle-class citizens. Their social status was supplemented with trace element analysis in order to reconstruct the dietary habits of the urban population. Concentrations of Sr and Zn indicated a predominantly vegetal diet. Potential DISH risk factors and associations were subsequently discussed and compared with our findings.

Evaluation Of Back Shape Using The ISIS Scanner

NASA Astrophysics Data System (ADS)

Turner-Smith, Alan R.; Thomas, David C.

1989-04-01

The Integrated Shape Investigation System (ISIS) is a structured light scanner and shape analysis system, developed as a safe alternative to follow-up radiographs for the clinical assessment of deformities of the human back. The system is described and results presented of several clinic studies. These show a significant correlation between ISIS measures and conventional radiographic measures of spinal curvature, such as the Cobb angle. The development of a predictor for deterioration in adolescent idiopathic scoliosis, based on surface shape weasures, is discussed.

Management of Spinal Deformities and Evidence of Treatment Effectiveness

PubMed Central

Bettany-Saltikov, Josette; Turnbull, Deborah; Ng, Shu Yan; Webb, Richard

2017-01-01

Introduction: The review evaluates the up-to-date evidence for the treatment of spinal deformities, including scoliosis and hyperkyphosis in adolescents and adults. Material and Methods: The PubMed database was searched for review articles, prospective controlled trials and randomized controlled trials related to the treatment of spinal deformities. Articles on syndromic scoliosis were excluded and so were the articles on hyperkyphosis of the spine with causes other than Scheuermann’s disease and osteoporosis. Articles on conservative and surgical treatments of idiopathic scoliosis, adult scoliosis and hyperkyphosis were also included. For retrospective papers, only studies with a follow up period exceeding 10 years were included. Results: The review showed that early-onset idiopathic scoliosis has a worse outcome than late-onset idiopathic scoliosis, which is rather benign. Patients with AIS function well as adults; they have no more health problems when compared to patients without scoliosis, other than a slight increase in back pain and aesthetic concern. Conservative treatment of adolescent idiopathic scoliosis (AIS) using physiotherapeutic scoliosis-specific exercises (PSSE), specifically PSSR and rigid bracing was supported by level I evidence. Yet to date, there is no high quality evidence (RCT`s) demonstrating that surgical treatment is superior to conservative treatment for the management of AIS. For adult scoliosis, there are only a few studies on the effectiveness of PSSEs and a conclusion cannot as yet be drawn. For hyperkyphosis, there is no high-quality evidence for physiotherapy, bracing or surgery for the treatment of adolescents and adults. However, bracing has been found to reduce thoracic hyperkyphosis, ranging from 55 to 80° in adolescents. In patients over the age of 60, bracing improves the balance score, and reduces spinal deformity and pain. Surgery is indicated in adolescents and adults in the presence of progression of kyphosis

Pre- and postoperative photographs and surgical outcomes in patients with Lenke type 1 adolescent idiopathic scoliosis.

PubMed

Albayrak, Akif; Buyuk, Abdul Fettah; Ucpunar, Hanifi; Balioglu, Mehmet Bulent; Kargin, Deniz; Kaygusuz, Mehmet Akif

2015-04-01

Clinical study with pre- and postoperative back photographs and postoperative Scoliosis Research Society-22 survey in patients who had undergone surgery for idiopathic scoliosis. To determine the effect of showing patients their photographs before and after surgery for idiopathic scoliosis on postoperative patient satisfaction. After scoliosis surgery, patient satisfaction may be limited because the patients cannot directly see their back and may forget the preoperative appearance. In 60 patients who had undergone surgery for correction of idiopathic scoliosis (Lenke type 1), pre- and postoperative photographs were taken from the anterior, posterior, and right and left lateral views. After surgery, patients in group 1 (30 patients) were shown the preoperative and most recent follow-up photographs, and patients in group 2 (30 patients) had routine evaluation but were not shown their photographs. All patients completed the Scoliosis Research Society-22 survey. Patients in both groups had similar age, sex, distribution of Lenke type and Risser sign, follow-up, and pre- and postoperative Cobb angles and balance (coronal and sagittal). A significant difference was observed between the groups for survey question 10 (which was about self-image), question 18 (which was about function and activity), and question 21 (which was about satisfaction) (P ≤ 0.05). There were no differences between patients in groups 1 and 2 in Scoliosis Research Society-22 domain or total scores. By showing patients the pre- and postoperative clinical photographs, patient satisfaction may be greater, as measured with some SRS-22 scores. This method may enable clinicians to positively change the patients' self-image perception after surgery for correction of scoliosis. 4.

Asymmetrical trunk movement during walking improved to normal range at 3 months after corrective posterior spinal fusion in adolescent idiopathic scoliosis.

PubMed

Wong-Chung, Daniel A C F; Schimmel, Janneke J P; de Kleuver, Marinus; Keijsers, Noël L W

2018-02-01

To investigate the effects of posterior spinal fusion (PSF) and curve type on upper body movements in Adolescent Idiopathic Scoliosis (AIS) patients during gait. Twenty-four girls (12-18 years) with AIS underwent PSF. 3D-Gait-analyses were performed preoperatively, at 3 months and 1 year postoperatively. Mean position (0° represents symmetry) and range of motion (ROM) of the trunk (thorax-relative-to-pelvis) in all planes were assessed. Lower body kinematics and spatiotemporal parameters were also evaluated. Mean trunk position improved from 7.0° to 2.9° in transversal plane and from 5.0° to - 0.8° in frontal plane at 3 months postoperative (p < 0.001), and was maintained at 1 year. Trunk ROM in transverse plane decreased from 9.6° to 7.5° (p < 0.001) after surgery. No effects of PSF were observed on the lower body kinematics during the gait cycle. Patients with a double curve had a more axial rotated trunk before and after surgery (p = 0.013). In AIS patients, during gait an evident asymmetrical position of the trunk improved to an almost symmetric situation already 3 months after PSF and was maintained at 1 year. Despite a reduction of trunk ROM, patients were able to maintain the same walking pattern in the lower extremities after surgery. This improvement of symmetry and maintenance of normal gait can explain the rapid recovery and well functioning in daily life of AIS patients, despite undergoing a fusion of large parts of their spine.

Adolescent idiopathic scoliosis (AIS), environment, exposome and epigenetics: a molecular perspective of postnatal normal spinal growth and the etiopathogenesis of AIS with consideration of a network approach and possible implications for medical therapy

PubMed Central

2011-01-01

Genetic factors are believed to play an important role in the etiology of adolescent idiopathic scoliosis (AIS). Discordant findings for monozygotic (MZ) twins with AIS show that environmental factors including different intrauterine environments are important in etiology, but what these environmental factors may be is unknown. Recent evidence for common chronic non-communicable diseases suggests epigenetic differences may underlie MZ twin discordance, and be the link between environmental factors and phenotypic differences. DNA methylation is one important epigenetic mechanism operating at the interface between genome and environment to regulate phenotypic plasticity with a complex regulation across the genome during the first decade of life. The word exposome refers to the totality of environmental exposures from conception onwards, comprising factors in external and internal environments. The word exposome is used here also in relation to physiologic and etiopathogenetic factors that affect normal spinal growth and may induce the deformity of AIS. In normal postnatal spinal growth we propose a new term and concept, physiologic growth-plate exposome for the normal processes particularly of the internal environments that may have epigenetic effects on growth plates of vertebrae. In AIS, we propose a new term and concept pathophysiologic scoliogenic exposome for the abnormal processes in molecular pathways particularly of the internal environment currently expressed as etiopathogenetic hypotheses; these are suggested to have deforming effects on the growth plates of vertebrae at cell, tissue, structure and/or organ levels that are considered to be epigenetic. New research is required for chromatin modifications including DNA methylation in AIS subjects and vertebral growth plates excised at surgery. In addition, consideration is needed for a possible network approach to etiopathogenesis by constructing AIS diseasomes. These approaches may lead through screening

Comparative Analysis of Interval, Skipped, and Key-vertebral Pedicle Screw Strategies for Correction in Patients With Lenke Type 1 Adolescent Idiopathic Scoliosis.

PubMed

Wang, Fei; Xu, Xi-Ming; Lu, Yanghu; Wei, Xian-Zhao; Zhu, Xiao-Dong; Li, Ming

2016-03-01

Pedicle screw constructs have become the mainstay for surgical correction in patients with spinal deformities. To reduce or avoid the risk of pedicle screw-based complications and to decrease the costs associated with pedicle screw instrumentation, some authors have introduced interval, skipped, and key-vertebral pedicle screw strategies for correction. However, there have been no comparisons of outcomes among these 3 pedicle screw-placement strategies.The aim of this study was to compare the correlative clinical outcomes of posterior correction and fusion with pedicle screw fixation using these 3 surgical strategies.Fifty-six consecutive patients with Lenke type 1 adolescent idiopathic scoliosis were included in this study. Twenty patients were treated with the interval pedicle screw strategy (IPSS), 20 with the skipped pedicle screw strategy (SPSS), and 16 with the key-vertebral pedicle screw strategy (KVPSS). Coronal and sagittal radiographs were analyzed before surgery, at 1 week after surgery, and at the last follow-up after surgery.There were no significant differences among the 3 groups regarding preoperative radiographic parameters. No significant difference was found between the IPSS and SPSS groups in correction of the main thoracic curve (70.8% vs 70.0%; P = 0.524). However, there were statistically significant differences between the IPSS and KVPSS groups (70.8% vs 64.9%) and between the SPSS and KVPSS groups (70.0% vs 64.9%) in correction of the main thoracic curve (P < 0.001 for both). Additionally, there were no significant differences among the 3 strategies for sagittal parameters at the immediate postoperative and last postoperative follow-up periods, though there were significant differences in the Cobb angle between the preoperative and immediate postoperative periods among the 3 groups, but not between the immediate postoperative and last follow-up periods. The amount of hospital charges in the SPSS group was significantly higher than

Angiotensin II type 1 and 2 receptors and lymphatic vessels modulate lung remodeling and fibrosis in systemic sclerosis and idiopathic pulmonary fibrosis.

PubMed

Parra, Edwin Roger; Ruppert, Aline Domingos Pinto; Capelozzi, Vera Luiza

2014-01-01

To validate the importance of the angiotensin II receptor isotypes and the lymphatic vessels in systemic sclerosis and idiopathic pulmonary fibrosis. We examined angiotensin II type 1 and 2 receptors and lymphatic vessels in the pulmonary tissues obtained from open lung biopsies of 30 patients with systemic sclerosis and 28 patients with idiopathic pulmonary fibrosis. Their histologic patterns included cellular and fibrotic non-specific interstitial pneumonia for systemic sclerosis and usual interstitial pneumonia for idiopathic pulmonary fibrosis. We used immunohistochemistry and histomorphometry to evaluate the number of cells in the alveolar septae and the vessels stained by these markers. Survival curves were also used. We found a significantly increased percentage of septal and vessel cells immunostained for the angiotensin type 1 and 2 receptors in the systemic sclerosis and idiopathic pulmonary fibrosis patients compared with the controls. A similar percentage of angiotensin 2 receptor positive vessel cells was observed in fibrotic non-specific interstitial pneumonia and usual interstitial pneumonia. A significantly increased percentage of lymphatic vessels was present in the usual interstitial pneumonia group compared with the non-specific interstitial pneumonia and control groups. A Cox regression analysis showed a high risk of death for the patients with usual interstitial pneumonia and a high percentage of vessel cells immunostained for the angiotensin 2 receptor in the lymphatic vessels. We concluded that angiotensin II receptor expression in the lung parenchyma can potentially control organ remodeling and fibrosis, which suggests that strategies aimed at preventing high angiotensin 2 receptor expression may be used as potential therapeutic target in patients with pulmonary systemic sclerosis and idiopathic pulmonary fibrosis.

Proton-induces and x-ray induced fluorescence analysis of scoliotic tissue

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

Panessa-Warren, B J; Kraner, H W; Jones, K W

1980-02-01

Adolescent idiopathic scoliosis is characterized by a curvature or assymetry of the spine which may become progressively more severe, with clinical symptoms appearing just prior to, or during, puberty. The incidence for scoliosis in the age group from 12 to 14 years of age has been reported as high as 8 to 10%, with more than 80% of the cases occurring in females. Although pathologic changes exist in muscles from both sides of the spinal curvature, and no statistically significant side differences have been reported, morphologic changes suggest that the concanve side is the most affected. This paper reports ourmore » preliminary data on the elemental composition of individual muscle fibers derived from convex, concave and gluteal scoliotic muscle, and erythrocytes from scoliotic and normal patients, analyzed by proton induced x-ray emission (PIXE) and x-ray fluorescence spectroscopy (XRF). A new type of specimen holder was designed for this study which offers low x-ray background, minimal absorption and maintenance of a moist environment around the specimen.« less

Spontaneous acute spinal subdural hematoma: spontaneous recovery from severe paraparesis--case report and review.

PubMed

Payer, Michael; Agosti, Reto

2010-11-01

Spontaneous idiopathic acute spinal subdural hematomas are highly exceptional. Neurological symptoms are usually severe, and rapid diagnosis with MRI is mandatory. Surgical evacuation has frequently been used therapeutically; however, spontaneous recovery in mild cases has also been reported. We present a case of spontaneous recovery from severe paraparesis after spontaneous acute SSDH, and review the English-speaking literature.

Dynamics of heart rate variability in patients with type 2 diabetes mellitus during spinal anaesthesia: prospective observational study.

PubMed

Lee, Su Hyun; Lee, Dong Hoon; Ha, Dong Hoon; Oh, Young Jun

2015-10-08

Little is known about the changes in autonomic function during spinal anaesthesia in type 2 diabetic patients. The purpose of the study was to assess the influence of spinal anaesthesia on the heart rate variability in type 2 diabetic patients according to the glycated hemoglobin (HbA1c) level. Sixty-six patients who were scheduled for elective orthostatic lower limb surgery were assigned to three groups (n = 22, each) according to HbA1c; controlled diabetes mellitus (HbA1c < 7 %), uncontrolled diabetes mellitus (HbA1c > 7 %) and the control group. The heart rate variability was measured 10 min before (T0), and at10 min (T1), 20 min (T2) and 30 min (T3) after spinal anaesthesia. Before spinal anaesthesia, total, low-and high-frequency power were significantly lower in the uncontrolled diabetec group than in other group (p < 0.05). During spinal anaesthesia, total, low- and high-frequency powers were did not change in the uncontrolled diabetec group while the low-frequency power in the controlled diabetec group was significantly depressed (p < 0.05). The ratio of low-to high-frequency was comparable among the groups, while it was reduced at T1-2 than at T0 in all the groups. The blood pressures were higher in the uncontrolled diabetec group than in the other groups. Spinal anaesthesia had an influence on the cardiac autonomic modulation in controlled diabetec patients, but not in uncontrolled diabetec patients. There were no differences in all haemodynamic variables during an adequate level of spinal anaesthesia in controlled and uncontrolled type 2 DM. ClinicalTrials.gov NCT02137057.

Difficulties in spinal needle use. Insertion characteristics and failure rates associated with 25-, 27- and 29-gauge Quincke-type spinal needles.

PubMed

Tarkkila, P; Huhtala, J; Salminen, U

1994-08-01

The effect of different size (25-, 27- and 29-gauge) Quincke-type spinal needles on the incidence of insertion difficulties and failure rates was investigated in a randomised, prospective study with 300 patients. The needle size was randomised but the insertion procedure was standardised. The time to achieve dural puncture was significantly longer with the 29-gauge spinal needle compared with the larger bore needles and was due to the greater flexibility of the thin needle. However, the difference was less than 1 min and cannot be considered clinically significant. There were no significant differences between groups in the number of insertion attempts or failures and the same sensory level of analgesia was reached with all the needle sizes studied. Postoperatively, no postdural puncture headaches occurred in the 29-gauge spinal needle group, whilst in the 25- and 27-gauge needle groups, the postdural puncture headache rates were 7.4% and 2.1% respectively. The incidence of backache was similar in all study groups. We conclude that dural puncture with a 29-gauge spinal needle is clinically as easy as with larger bore needles and its use is indicated in patients who have a high risk of postdural puncture headache.

Idiopathic anaphylaxis.

PubMed

Fenny, Nana; Grammer, Leslie C

2015-05-01

Idiopathic anaphylaxis is a diagnosis of exclusion after other causes have been thoroughly evaluated and excluded. The pathogenesis of idiopathic anaphylaxis remains uncertain, although increased numbers of activated lymphocytes and circulating histamine-releasing factors have been implicated. Signs and symptoms of patients diagnosed with idiopathic anaphylaxis are indistinguishable from the manifestations of other forms of anaphylaxis. Treatment regimens are implemented based on the frequency and severity of patient symptoms and generally include the use of epinephrine autoinjectors, antihistamines, and steroids. The prognosis of idiopathic anaphylaxis is generally favorable with well-established treatment regimens and effective patient education. Copyright © 2015 Elsevier Inc. All rights reserved.

Idiopathic Cervical Hematomyelia in an Infant: Spinal Cord Injury without Radiographic Abnormality Caused by a Trivial Trauma? Case Report and Review of the Literature.

PubMed

Fiaschi, Pietro; Severino, Mariasavina; Ravegnani, Giuseppe Marcello; Piatelli, Gianluca; Consales, Alessandro; Accogli, Andrea; Capra, Valeria; Cama, Armando; Pavanello, Marco

2016-06-01

Spontaneous or idiopathic intramedullary bleeding is a very rare event in pediatric patients. This diagnosis requires an extended clinical, laboratory, and radiologic work-up to rule out all potential causes of hematomyelia. However, children may present with hematomyelia or spinal cord injury without radiographic abnormality even after a minor trauma. A 15-month-old girl presented with a 24-hour history of progressive neurologic deficits. A trivial trauma had occurred a few days before the clinical onset. Head computed tomography scan and craniospinal magnetic resonance imaging revealed an isolated hemorrhagic central medullary lesion extending from the obex to C3 level. No underlying causes of intramedullary bleeding were identified. In the absence of obvious vascular abnormalities, the patient underwent an urgent occipitocervical decompression with hematoma evacuation. Postoperatively, the patient's motor symptoms rapidly resolved, and she was discharged with cervical collar immobilization. We discuss the differential diagnosis of intramedullary bleeding in children, focusing on the diagnostic protocol and therapeutic options in this age group. Copyright © 2016 Elsevier Inc. All rights reserved.

Impact of vessel curvature on neointimal healing after stent implantation as assessed by optical coherence tomography.

PubMed

Fu, Yandong; Zhang, Shaotao; Du, Hongwei; Li, Lulu; Wang, Chao; Zheng, Gonghui; Wang, Yan; Dong, Hui; Jia, Haibo; Yu, Bo

2018-04-01

Previous studies have indicated that stent implantation could alter the vessel geometry, which may impact the neointimal healing process. Curvature is an important parameter for evaluating vessel geometry. The purpose of our study was to investigate the relationship between vessel curvature and neointimal healing after stent implantation. Fifty-nine patients with acute coronary syndrome (ACS) who underwent stent implantation were enrolled in the study. According to the post-percutaneous coronary intervention vessel curvature measured by quantitative coronary angiography, patients were divided into high (n = 30) and low (n = 29) curvature groups. Neointimal thickness and area together with the neointimal type were assessed by optical coherence tomography at a 6-month follow-up. Baseline clinical characteristics were comparable between the 2 groups. The vessel curvature at pre- and 6-month follow-up was significantly higher in the high curvature group than the low curvature group. At 6-month follow-up, neointimal thickness (0.22 [0.08-0.32] mm vs. 0.10 [0.07-0.16] mm, P = .043) and neointimal area (1.86 [0.66-2.66] vs. 0.82 [0.60-1.41] mm, P = .030) were significantly higher in the high curvature group than the low curvature group. In the high curvature group, the incidence of the heterogeneous neointimal type was higher than that in the low curvature group (50.00% vs. 17.20%, respectively, P = .004), whereas the frequency of the homogeneous neointimal type was lower (43.30% vs. 82.80%, respectively, P = .004) in the high curvature group than the low curvature group. Higher vessel curvature after stent implantation may potentially have an impact on the neointimal healing with a higher incidence of heterogeneous neointimal.

Manual therapy as a conservative treatment for adolescent idiopathic scoliosis: a systematic review

PubMed Central

Romano, Michele; Negrini, Stefano

2008-01-01

Background The treatment of adolescent idiopathic scoliosis is contingent upon many variables. Simple observation is enough for less serious curvatures, but for very serious cases surgical intervention could be proposed. Between these there is a wide range of different treatments. Manual therapy is commonly used: the aim of this paper is to verify the data existing in the literature on the efficacy of this approach. Methods A systematic review of the scientific literature published internationally has been performed. We have included in the term manual therapy all the manipulative and generally passive techniques performed by an external operator. In a more specific meaning, osteopathic, chiropractic and massage techniques have been considered as manipulative therapeutic methods. We performed our systematic research in Medline, Embase, Cinhal, Cochrane Library, Pedro with the following terms: idiopathic scoliosis combined with chiropractic; manipulation; mobilization; manual therapy; massage; osteopathy; and therapeutic manipulation. The criteria for inclusion were as follows: Any kind of research; diagnosis of adolescent idiopathic scoliosis; patients treated exclusively by one of the procedures established as a standard for this review (chiropractic manipulation, osteopathic techniques, massage); and outcome in Cobb degrees. Results We founded 145 texts, but only three papers were relevant to our study. However, no one of the three satisfied all the required inclusion criteria because they were characterized by a combination of manual techniques and other therapeutic approaches. Conclusion The lack of any kind of serious scientific data does not allow us to draw any conclusion on the efficacy of manual therapy as an efficacious technique for the treatment of Adolescent idiopathic scoliosis. PMID:18211702

Manual therapy as a conservative treatment for adolescent idiopathic scoliosis: a systematic review.

PubMed

Romano, Michele; Negrini, Stefano

2008-01-22

The treatment of adolescent idiopathic scoliosis is contingent upon many variables. Simple observation is enough for less serious curvatures, but for very serious cases surgical intervention could be proposed. Between these there is a wide range of different treatments. Manual therapy is commonly used: the aim of this paper is to verify the data existing in the literature on the efficacy of this approach. A systematic review of the scientific literature published internationally has been performed. We have included in the term manual therapy all the manipulative and generally passive techniques performed by an external operator. In a more specific meaning, osteopathic, chiropractic and massage techniques have been considered as manipulative therapeutic methods. We performed our systematic research in Medline, Embase, Cinhal, Cochrane Library, Pedro with the following terms: idiopathic scoliosis combined with chiropractic; manipulation; mobilization; manual therapy; massage; osteopathy; and therapeutic manipulation. The criteria for inclusion were as follows: Any kind of research; diagnosis of adolescent idiopathic scoliosis; patients treated exclusively by one of the procedures established as a standard for this review (chiropractic manipulation, osteopathic techniques, massage); and outcome in Cobb degrees. We founded 145 texts, but only three papers were relevant to our study. However, no one of the three satisfied all the required inclusion criteria because they were characterized by a combination of manual techniques and other therapeutic approaches. The lack of any kind of serious scientific data does not allow us to draw any conclusion on the efficacy of manual therapy as an efficacious technique for the treatment of Adolescent idiopathic scoliosis.

The spinal inhibition of N-type voltage-gated calcium channels selectively prevents scratching behavior in mice.

PubMed

Maciel, I S; Azevedo, V M; Pereira, T C; Bogo, M R; Souza, A H; Gomez, M V; Campos, M M

2014-09-26

The present study investigated the effects of pharmacological spinal inhibition of voltage-gated calcium channels (VGCC) in mouse pruritus. The epidural administration of P/Q-type MVIIC or PhTx3.3, L-type verapamil, T-type NNC 55-0396 or R-type SNX-482 VGCC blockers failed to alter the scratching behavior caused by the proteinase-activated receptor 2 (PAR-2) activator trypsin, injected into the mouse nape skin. Otherwise, trypsin-elicited pruritus was markedly reduced by the spinal administration of preferential N-type VGCC inhibitors MVIIA and Phα1β. Time-course experiments revealed that Conus magus-derived toxin MVIIA displayed significant effects when dosed from 1h to 4h before trypsin, while the anti-pruritic effects of Phα1β from Phoneutria nigriventer remained significant for up to 12h. In addition to reducing trypsin-evoked itching, MVIIA or Phα1β also prevented the itching elicited by intradermal (i.d.) injection of SLIGRL-NH2, compound 48/80 or chloroquine, although they did not affect H2O2-induced scratching behavior. Furthermore, the co-administration of MVIIA or Phα1β markedly inhibited the pruritus caused by the spinal injection of gastrin-releasing peptide (GRP), but not morphine. Notably, the epidural administration of MVIIA or Phα1β greatly prevented the chronic pruritus allied to dry skin model. However, either tested toxin failed to alter the edema formation or neutrophil influx caused by trypsin, whereas they significantly reduced the c-Fos activation in laminas I, II and III of the spinal cord. Our data bring novel evidence on itching transmission mechanisms, pointing out the therapeutic relevance of N-type VGCC inhibitors to control refractory pruritus. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

The "beneficial" effects of locomotor training after various types of spinal lesions in cats and rats.

PubMed

Rossignol, Serge; Martinez, Marina; Escalona, Manuel; Kundu, Aritra; Delivet-Mongrain, Hugo; Alluin, Olivier; Gossard, Jean-Pierre

2015-01-01

This chapter reviews a number of experiments on the recovery of locomotion after various types of spinal lesions and locomotor training mainly in cats. We first recall the major evidence on the recovery of hindlimb locomotion in completely spinalized cats at the T13 level and the role played by the spinal locomotor network, also known as the central pattern generator, as well as the beneficial effects of locomotor training on this recovery. Having established that hindlimb locomotion can recover, we raise the issue as to whether spinal plastic changes could also contribute to the recovery after partial spinal lesions such as unilateral hemisections. We found that after such hemisection at T10, cats could recover quadrupedal locomotion and that deficits could be improved by training. We further showed that, after a complete spinalization a few segments below the first hemisection (at T13, i.e., the level of previous studies on spinalization), cats could readily walk with the hindlimbs within hours of completely severing the remaining spinal tracts and not days as is usually the case with only a single complete spinalization. This suggests that neuroplastic changes occurred below the first hemisection so that the cat was already primed to walk after the spinalization subsequent to the hemispinalization 3 weeks before. Of interest is the fact that some characteristic kinematic features in trained or untrained hemispinalized cats could remain after complete spinalization, suggesting that spinal changes induced by training could also be durable. Other studies on reflexes and on the pattern of "fictive" locomotion recorded after curarization corroborate this view. More recent work deals with training cats in more demanding situations such as ladder treadmill (vs. flat treadmill) to evaluate how the locomotor training regimen can influence the spinal cord. Finally, we report our recent studies in rats using compressive lesions or surgical complete spinalization and find

Intrinsic curvature in wool fibres is determined by the relative length of orthocortical and paracortical cells.

PubMed

Harland, Duane P; Vernon, James A; Woods, Joy L; Nagase, Shinobu; Itou, Takashi; Koike, Kenzo; Scobie, David A; Grosvenor, Anita J; Dyer, Jolon M; Clerens, Stefan

2018-03-22

Hair curvature underpins structural diversity and function in mammalian coats, but what causes curl in keratin hair fibres? To obtain structural data to determine one aspect of this question, we used confocal microscopy to provide in situ measurements of the two cell types that make up the cortex of merino wool fibres, which was chosen as a well-characterised model system representative of narrow diameter hairs, such as underhairs. We measured orthocortical and paracortical cross-sectional areas, and cortical cell lengths, within individual fibre snippets of defined uniplanar curvature. This allowed a direct test of two long-standing theories of the mechanism of curvature in hairs. We found evidence contradicting the theory that curvature results from there being more cells on the side of the fibre closest to the outside, or convex edge, of curvature. In all cases, the orthocortical cells close to the outside of curvature were longer than paracortical cells close to the inside of the curvature, which supports the theory that curvature is underpinned by differences in cell type length. However, the latter theory also implies that, for all fibres, curvature should correlate with the proportions of orthocortical and paracortical cells, and we found no evidence for this. In merino wool, it appears that the absolute length of cells of each type and proportion of cells varies from fibre to fibre, and only the difference between the length of the two cell types is important. Implications for curvature in higher diameter hairs, such as guard hairs and those on the human scalp, are discussed. © 2018. Published by The Company of Biologists Ltd.

Functional Investigation of a Non-coding Variant Associated with Adolescent Idiopathic Scoliosis in Zebrafish: Elevated Expression of the Ladybird Homeobox Gene Causes Body Axis Deformation

PubMed Central

Guo, Long; Yamashita, Hiroshi; Kou, Ikuyo; Takimoto, Aki; Meguro-Horike, Makiko; Horike, Shin-ichi; Sakuma, Tetsushi; Miura, Shigenori; Adachi, Taiji; Yamamoto, Takashi; Ikegawa, Shiro; Hiraki, Yuji; Shukunami, Chisa

2016-01-01

Previously, we identified an adolescent idiopathic scoliosis susceptibility locus near human ladybird homeobox 1 (LBX1) and FLJ41350 by a genome-wide association study. Here, we characterized the associated non-coding variant and investigated the function of these genes. A chromosome conformation capture assay revealed that the genome region with the most significantly associated single nucleotide polymorphism (rs11190870) physically interacted with the promoter region of LBX1-FLJ41350. The promoter in the direction of LBX1, combined with a 590-bp region including rs11190870, had higher transcriptional activity with the risk allele than that with the non-risk allele in HEK 293T cells. The ubiquitous overexpression of human LBX1 or either of the zebrafish lbx genes (lbx1a, lbx1b, and lbx2), but not FLJ41350, in zebrafish embryos caused body curvature followed by death prior to vertebral column formation. Such body axis deformation was not observed in transcription activator-like effector nucleases mediated knockout zebrafish of lbx1b or lbx2. Mosaic expression of lbx1b driven by the GATA2 minimal promoter and the lbx1b enhancer in zebrafish significantly alleviated the embryonic lethal phenotype to allow observation of the later onset of the spinal curvature with or without vertebral malformation. Deformation of the embryonic body axis by lbx1b overexpression was associated with defects in convergent extension, which is a component of the main axis-elongation machinery in gastrulating embryos. In embryos overexpressing lbx1b, wnt5b, a ligand of the non-canonical Wnt/planar cell polarity (PCP) pathway, was significantly downregulated. Injection of mRNA for wnt5b or RhoA, a key downstream effector of Wnt/PCP signaling, rescued the defective convergent extension phenotype and attenuated the lbx1b-induced curvature of the body axis. Thus, our study presents a novel pathological feature of LBX1 and its zebrafish homologs in body axis deformation at various stages of

Effect of spinal needle characteristics on measurement of spinal canal opening pressure.

PubMed

Bellamkonda, Venkatesh R; Wright, Thomas C; Lohse, Christine M; Keaveny, Virginia R; Funk, Eric C; Olson, Michael D; Laack, Torrey A

2017-05-01

A wide variety of spinal needles are used in clinical practice. Little is currently known regarding the impact of needle length, gauge, and tip type on the needle's ability to measure spinal canal opening pressure. This study aimed to investigate the relationship between these factors and the opening-pressure measurement or time to obtain an opening pressure. Thirteen distinct spinal needles, chosen to isolate the effects of length, gauge, and needle-point type, were prospectively tested on a lumbar puncture simulator. The key outcomes were the opening-pressure measurement and the time required to obtain that measure. Pressures were recorded at 10-s intervals until 3 consecutive, identical readings were observed. Time to measure opening pressure increased with increasing spinal needle length, increasing gauge, and the Quincke-type (cutting) point (P<0.001 for all). The time to measurement ranged from 30s to 530s, yet all needle types were able to obtain a consistent opening pressure measure. Although opening pressure estimates are unlikely to vary markedly by needle type, the time required to obtain the measurement increased with increasing needle length and gauge and with Quincke-type needles. Copyright © 2017 Elsevier Inc. All rights reserved.

Assessment of spinal flexibility in adolescent idiopathic scoliosis: suspension versus side-bending radiography.

PubMed

Lamarre, Marie-Eve; Parent, Stefan; Labelle, Hubert; Aubin, Carl-Eric; Joncas, Julie; Cabral, Anne; Petit, Yvan

2009-03-15

Prospective evaluation of a new suspension test to determine curve flexibility in adolescent idiopathic scoliosis (AIS) in comparison with erect side-bending. To verify whether the suspension is a better method than side-bending to estimate curve reducibility and to assess spine flexibility. Spinal flexibility is a decisive biomechanical parameter for the planning of AIS surgery. Side-bending is often referred as the gold standard, but it has a low reproducibility and there is no agreement amongst surgeons about the most advantageous method to use. Even more, every technique evaluates reducibility instead of flexibility since the forces involved in the change in shape of the spine are not considered. Eighteen patients scheduled for AIS surgery were studied. Preoperative radiological evaluation consisted of 4 radiographs: standing posteroanterior, left and right erect side-bending, and suspension. The side-bending and the suspension tests were compared on the basis of the apical vertebrae derotation and the scoliosis curve reduction. Frontal and axial flexibility indices, expressed as the ratio between the moment induced by the body weight and the reduction, were calculated from the suspension data. The average scoliosis curve reduction and apical vertebra derotation were 21 degrees (37%) and 3 degrees (12%), respectively for erect side-bending and 26 degrees (39%) and 7 degrees (28%), respectively for suspension. The erect side-bending test generated a larger curve reduction (P = 0.05) when considering the moderate curves only and the suspension test (P = 0.02) when considering the severe curves. The suspension test produced a larger axial derotation (P = 0.007) when considering all the curves. The average traction force during suspension was 306 N (187 N-377 N). The average estimation for the frontal flexibility index was 1.64 degrees/Nm (0.84-2.82) and 0.51 degrees/Nm (0.01-1.39) for the axial flexibility index. Results of this study demonstrate the feasibility

The speed-curvature power law of movements: a reappraisal.

PubMed

Zago, Myrka; Matic, Adam; Flash, Tamar; Gomez-Marin, Alex; Lacquaniti, Francesco

2018-01-01

Several types of curvilinear movements obey approximately the so called 2/3 power law, according to which the angular speed varies proportionally to the 2/3 power of the curvature. The origin of the law is debated but it is generally thought to depend on physiological mechanisms. However, a recent paper (Marken and Shaffer, Exp Brain Res 88:685-690, 2017) claims that this power law is simply a statistical artifact, being a mathematical consequence of the way speed and curvature are calculated. Here we reject this hypothesis by showing that the speed-curvature power law of biological movements is non-trivial. First, we confirm that the power exponent varies with the shape of human drawing movements and with environmental factors. Second, we report experimental data from Drosophila larvae demonstrating that the power law does not depend on how curvature is calculated. Third, we prove that the law can be violated by means of several mathematical and physical examples. Finally, we discuss biological constraints that may underlie speed-curvature power laws discovered in empirical studies.

Twisted surfaces with vanishing curvature in Galilean 3-space

NASA Astrophysics Data System (ADS)

Dede, Mustafa; Ekici, Cumali; Goemans, Wendy; Ünlütürk, Yasin

In this work, we define twisted surfaces in Galilean 3-space. In order to construct these surfaces, a planar curve is subjected to two simultaneous rotations, possibly with different rotation speeds. The existence of Euclidean rotations and isotropic rotations leads to three distinct types of twisted surfaces in Galilean 3-space. Then we classify twisted surfaces in Galilean 3-space with zero Gaussian curvature or zero mean curvature.

Intrathecal P/Q- and R-type calcium channel blockades on spinal substance P release and c-Fos expression

PubMed Central

Terashima, Tetsuji; Xu, Qinghao; Yamaguchi, Shigeki; Yaksh, Tony L.

2013-01-01

Intrathecal (IT) studies have shown that several voltage sensitive calcium channels (VSCCs), such as the L-, N- and T-type may play roles in nociception and that of these only the N-type regulates primary afferent substance P (SP) release. However, the actions of other VSCCs at the spinal level are not well known. We investigated the roles of spinal P/Q- and R-type VSCCs, by IT administration of R-type (SNX-482) and P/Q-type (ω-agatoxin IVA) VSCC blockers on intraplantar formalin-evoked flinching, SP release from primary afferents and c-Fos expression in spinal dorsal horn. Intraplantar injection of formalin (2.5%, 50 µL) produced an intense, characteristic biphasic paw flinching response. In rats with IT catheters, IT SNX-482 (0.5 µg) reduced formalin-evoked paw flinching in both phase 1 and 2 compared with vehicle. Intraplantar formalin caused robust neurokinin 1 receptor (NK1r) internalization (indicating SP release) and c-Fos expression in the ipsilateral dorsal horn, which were blocked by IT SNX-482. IT ω-agatoxin IVA (0.03, 0.125 and 0.5 µg) did not reduce formalin-evoked paw flinching or c-Fos expression at any doses, with higher doses resulting in motor dysfunction. Thus, we demonstrated that blockade of spinal R-type, but not P/Q type VSCCs attenuated formalin-induced pain behavior, NK1r internalization and c-Fos expression in the superficial dorsal horn. This study supports a role for Cav2.3 in presynaptic neurotransmitter release from peptidergic nociceptive afferents and pain behaviors. PMID:23810829

Curvature-undulation coupling as a basis for curvature sensing and generation in bilayer membranes.

PubMed

Bradley, Ryan P; Radhakrishnan, Ravi

2016-08-30

We present coarse-grained molecular dynamics simulations of the epsin N-terminal homology domain interacting with a lipid bilayer and demonstrate a rigorous theoretical formalism and analysis method for computing the induced curvature field in varying concentrations of the protein in the dilute limit. Our theory is based on the description of the height-height undulation spectrum in the presence of a curvature field. We formulated an objective function to compare the acquired undulation spectrum from the simulations to that of the theory. We recover the curvature field parameters by minimizing the objective function even in the limit where the protein-induced membrane curvature is of the same order as the amplitude due to thermal undulations. The coupling between curvature and undulations leads to significant predictions: (i) Under dilute conditions, the proteins can sense a site of spontaneous curvature at distances much larger than their size; (ii) as the density of proteins increases the coupling focuses and stabilizes the curvature field to the site of the proteins; and (iii) the mapping of the protein localization and the induction of a stable curvature is a cooperative process that can be described through a Hill function.

Understanding how axial loads on the spine influence segmental biomechanics for idiopathic scoliosis patients: A magnetic resonance imaging study.

PubMed

Little, J P; Pearcy, M J; Izatt, M T; Boom, K; Labrom, R D; Askin, G N; Adam, C J

2016-02-01

Segmental biomechanics of the scoliotic spine are important since the overall spinal deformity is comprised of the cumulative coronal and axial rotations of individual joints. This study investigates the coronal plane segmental biomechanics for adolescent idiopathic scoliosis patients in response to physiologically relevant axial compression. Individual spinal joint compliance in the coronal plane was measured for a series of 15 idiopathic scoliosis patients using axially loaded magnetic resonance imaging. Each patient was first imaged in the supine position with no axial load, and then again following application of an axial compressive load. Coronal plane disc wedge angles in the unloaded and loaded configurations were measured. Joint moments exerted by the axial compressive load were used to derive estimates of individual joint compliance. The mean standing major Cobb angle for this patient series was 46°. Mean intra-observer measurement error for endplate inclination was 1.6°. Following loading, initially highly wedged discs demonstrated a smaller change in wedge angle, than less wedged discs for certain spinal levels (+2,+1,-2 relative to the apex, (p<0.05)). Highly wedged discs were observed near the apex of the curve, which corresponded to lower joint compliance in the apical region. While individual patients exhibit substantial variability in disc wedge angles and joint compliance, overall there is a pattern of increased disc wedging near the curve apex, and reduced joint compliance in this region. Approaches such as this can provide valuable biomechanical data on in vivo spinal biomechanics of the scoliotic spine, for analysis of deformity progression and surgical planning. Copyright © 2015 Elsevier Ltd. All rights reserved.

Early changes in muscle atrophy and muscle fiber type conversion after spinal cord transection and peripheral nerve transection in rats.

PubMed

Higashino, Kosaku; Matsuura, Tetsuya; Suganuma, Katsuyoshi; Yukata, Kiminori; Nishisho, Toshihiko; Yasui, Natsuo

2013-05-20

Spinal cord transection and peripheral nerve transection cause muscle atrophy and muscle fiber type conversion. It is still unknown how spinal cord transection and peripheral nerve transection each affect the differentiation of muscle fiber type conversion mechanism and muscle atrophy. The aim of our study was to evaluate the difference of muscle weight change, muscle fiber type conversion, and Peroxisome proliferator-activated receptor-γ coactivatior-1α (PGC-1α) expression brought about by spinal cord transection and by peripheral nerve transection. Twenty-four Wistar rats underwent surgery, the control rats underwent a laminectomy; the spinal cord injury group underwent a spinal cord transection; the denervation group underwent a sciatic nerve transection. The rats were harvested of the soleus muscle and the TA muscle at 0 week, 1 week and 2 weeks after surgery. Histological examination was assessed using hematoxylin and eosin (H&E) staining and immunofluorescent staing. Western blot was performed with 3 groups. Both sciatic nerve transection and spinal cord transection caused muscle atrophy with the effect being more severe after sciatic nerve transection. Spinal cord transection caused a reduction in the expression of both sMHC protein and PGC-1α protein in the soleus muscle. On the other hand, sciatic nerve transection produced an increase in expression of sMHC protein and PGC-1α protein in the soleus muscle. The results of the expression of PGC-1α were expected in other words muscle atrophy after sciatic nerve transection is less than after spinal cord transection, however muscle atrophy after sciatic nerve transection was more severe than after spinal cord transection. In the conclusion, spinal cord transection diminished the expression of sMHC protein and PGC-1α protein in the soleus muscle. On the other hand, sciatic nerve transection enhanced the expression of sMHC protein and PGC-1α protein in the soleus muscle.

Prediction of Curve Progression in Idiopathic Scoliosis: Validation of the Sanders Skeletal Maturity Staging System.

PubMed

Sitoula, Prakash; Verma, Kushagra; Holmes, Laurens; Gabos, Peter G; Sanders, James O; Yorgova, Petya; Neiss, Geraldine; Rogers, Kenneth; Shah, Suken A

2015-07-01

Retrospective case series. This study aimed to validate the Sanders Skeletal Maturity Staging System and to assess its correlation to curve progression in idiopathic scoliosis. The Sanders Skeletal Maturity Staging System has been used to predict curve progression in idiopathic scoliosis. This study intended to validate that initial study with a larger sample size. We retrospectively reviewed 1100 consecutive patients with idiopathic scoliosis between 2005 and 2011. Girls aged 8 to 14 years (<2 yr postmenarche) and boys aged 10 to 16 years who had obtained at least 1 hand and spine radiograph on the same day for evaluation of skeletal age and scoliosis curve magnitude were followed to skeletal maturity (Risser stage 5 or fully capped Risser stage 4), curve progression to 50° or greater, or spinal fusion. Patients with nonidiopathic curves were excluded. There were 161 patients: 131 girls (12.3 ± 1.2 yr) and 30 boys (13.9 ± 1.1 yr). The distribution of patients within Sanders stage (SS) 1 through 7 was 7, 28, 41, 45, 7, 31, and 2 patients, respectively; modified Lenke curve types 1 to 6 were 26, 12, 63, 5, 38, and 17 patients, respectively. All patients in SS2 with initial Cobb angles of 25° or greater progressed, and patients in SS1 and SS3 with initial Cobb angles of 35° or greater progressed. Similarly, all patients with initial Cobb angles of 40° or greater progressed except those in SS7. Conversely, none of the patients with initial Cobb angles of 15° or less or those in SS5, SS6, and SS7 with initial Cobb angles of 30° or less progressed. Predictive progression of 67%, 50%, 43%, 27%, and 60% was observed for subgroups SS1/30°, SS2/20°, SS3/30°, SS4/30°, and SS6/35° respectively. This larger cohort shows a strong predictive correlation between SS and initial Cobb angle for probability of curve progression in idiopathic scoliosis. 3.

Correlates of the peak height velocity in girls with idiopathic scoliosis.

PubMed

Sanders, James O; Browne, Richard H; Cooney, Timothy E; Finegold, David N; McConnell, Sharon J; Margraf, Susan A

2006-09-15

Prospective longitudinal. Determine correlates of the peak height velocity (PHV) in girls with idiopathic scoliosis. Only identifiable retrospectively, the PHV is the most useful known maturity marker in idiopathic scoliosis. Clinically useful correlates are needed to make PHV timing helpful. A total of 24 immature girls with idiopathic scoliosis were followed with serial heights, sexual staging, skeletal ages, spinal radiographs, insulin-like growth factor (IGF)-1, IGF binding protein-3, dehydroepiandrosterone sulfate, estradiol, bone-specific alkaline phosphatase, and osteocalcin levels. These markers were correlated to PHV timing. There were 14 girls who had identifiable growth peaks that averaged 10.5 +/- 1.8 cm/y at age 11.7 +/- 1 years. At the PHV, all girls were Risser 0 with open triradiate cartilages. On a skeletal age radiograph, digital uncapped phalangeal epiphyses were indicative of pre-PHV and fused epiphyses of post-PHV. Capped but unfused epiphyses were indeterminate. Tanner stage 1 for breast strongly indicates pre-PHV. Stage 3 for breast and pubic hair occurred at or after the PHV, and stage 4 always occurred after PHV. Higher IGF-1 and estradiol levels after PHV are potentially discriminatory. The PHV occurs during Risser 0 with open triradiate cartilages. If triradiate cartilages are open, then Tanner stages, IGF-1, estradiol levels, and the appearance of the epiphyses on a skeletal age radiograph are useful in determining status before or after PHV.

A validation study on the traditional Chinese version of Spinal Appearance Questionnaire for adolescent idiopathic scoliosis.

PubMed

Guo, Jing; Lau, Ajax Hong Yin; Chau, Jack; Ng, Bobby Kin Wah; Lee, Kwong Man; Qiu, Yong; Cheng, Jack Chun Yiu; Lam, Tsz Ping

2016-10-01

"Simplified Chinese" version of Spinal Appearance Questionnaire (SC-SAQ) for patients with adolescent idiopathic scoliosis (AIS) was available but did not fit for communities using "Traditional Chinese" as their primary language. We developed a traditional Chinese version of SAQ (TC-SAQ) and evaluated its reliability and validity. TC-SAQ was administered to 112 AIS patients, of which 101 bilingual (English and Chinese) patients completed E-SAQ and the traditional Chinese version of Scoliosis Research Society-22 questionnaire (TC-SRS-22). Internal consistency and test-retest reliability were evaluated. Concurrent validity was evaluated by comparing TC-SAQ score with E-SAQ score, and convergent validity by comparing TC-SAQ score with TC-SRS-22 self-image domain score, and discriminant validity by analyzing the relationship between TC-SAQ score and patients' characteristics. Internal consistency of individual TC-SAQ domain was high (Cronbach's α = 0.785 to 0.940), except for general (Cronbach's α = 0.665) and shoulders (Cronbach's α = 0.421) domain. Test-retest reliability of TC-SAQ was good (ICCs of each domain from 0.798 to 0.865). Concurrent validity demonstrated an excellent correlation between TC-SAQ and E-SAQ scores (r = 0.820 to 0.954, P < 0.0001 for all domains). Correlation between TC-SAQ domains and TC-SRS-22 self-image domain was weak to moderate. TC-SAQ total score and individual domain scores (except waist and chest domains) were positively correlated to major curve magnitude. TC-SAQ had good internal consistency and test-retest reliability. Concurrent validity evaluated against the original English version was excellent. TC-SAQ was both reliable and valid for clinical use for AIS patients using traditional Chinese as their primary language.

Do adult men with untreated ventral penile curvature have adverse outcomes?

PubMed

Menon, Vani; Breyer, Benjamin; Copp, Hillary L; Baskin, Laurence; Disandro, Michael; Schlomer, Bruce J

2016-02-01

Congenital ventral penile curvature without hypospadias is often treated surgically in childhood. The history of untreated ventral curvature is unknown. This study's aim was to examine the association of untreated ventral penile curvature with various sexual and psychosexual outcomes. An electronic survey was advertised to men older than 18 years on Facebook. Men with possible ventral penile curvature identified themselves by choosing sketches that most closely represented their anatomy. Outcomes assessed included: Sexual Health Inventory for Men, difficulty of intercourse because of curvature, International Prostate Symptom Score, Penile Perception Score, psychosexual milestones, paternity, infertility, sitting to urinate, and the CDC HRQOL-4 module. Among participants, 81 out of 684 men (11.8%) reported untreated ventral penile curvature. Participants with self-reported curvature noted more difficulty with intercourse because of curvature (4.5 vs 4.9, p < 0.001), more unhealthy mental days (8.6 vs 6.2, p = 0.02), and increased dissatisfaction with penile self-perception compared with men without reported curvature (8.6 vs 9.5, p < 0.001). Men with possible untreated ventral curvature reported worse penile perception scores, more mentally unhealthy days, and increased difficulty with intercourse secondary to curvature compared with men without curvature. A limitation to this study is selection bias; responses collected were self-reported from survey volunteers. Additionally, the question identifying ventral penile curvature is not validated but performed well in pretesting. Most questions were from validated surveys, but some were modeled after validated surveys and/or contained high face validity types of questions. Men with possible untreated ventral penile curvature reported more dissatisfaction with penile appearance, increased difficulty with intercourse, and more unhealthy mental days. Given high success rates, low complications, and improved outcomes after

Do adult men with untreated ventral penile curvature have adverse outcomes?

PubMed Central

Menon, Vani; Breyer, Benjamin; Copp, Hillary L.; Baskin, Laurence; Disandro, Michael; Schlomer, Bruce J.

2016-01-01

Summary Introduction Congenital ventral penile curvature without hypospadias is often treated surgically in childhood. The history of untreated ventral curvature is unknown. Objective This study’s aim was to examine the association of untreated ventral penile curvature with various sexual and psychosexual outcomes. Study design An electronic survey was advertised to men older than 18 years on Facebook. Men with possible ventral penile curvature identified themselves by choosing sketches that most closely represented their anatomy. Outcomes assessed included: Sexual Health Inventory for Men, difficulty of intercourse because of curvature, International Prostate Symptom Score, Penile Perception Score, psychosexual milestones, paternity, infertility, sitting to urinate, and the CDC HRQOL-4 module. Results Among participants, 81 out of 684 men (11.8%) reported untreated ventral penile curvature. Participants with self-reported curvature noted more difficulty with intercourse because of curvature (4.5 vs 4.9, p < 0.001), more unhealthy mental days (8.6 vs 6.2, p = 0.02), and increased dissatisfaction with penile self-perception compared with men without reported curvature (8.6 vs 9.5, p < 0.001). Discussion Men with possible untreated ventral curvature reported worse penile perception scores, more mentally unhealthy days, and increased difficulty with intercourse secondary to curvature compared with men without curvature. A limitation to this study is selection bias; responses collected were self-reported from survey volunteers. Additionally, the question identifying ventral penile curvature is not validated but performed well in pretesting. Most questions were from validated surveys, but some were modeled after validated surveys and/or contained high face validity types of questions. Conclusion Men with possible untreated ventral penile curvature reported more dissatisfaction with penile appearance, increased difficulty with intercourse, and more unhealthy mental

Idiopathic Ophthalmodynia and Idiopathic Rhinalgia: A Prospective Series of 16 New Cases.

PubMed

Pareja, Juan A; Montojo, Teresa; Guerrero, Ángel L; Álvarez, Mónica; Porta-Etessam, Jesús; Cuadrado, María L

2015-01-01

Idiopathic ophthalmodynia and idiopathic rhinalgia were described a few years ago. These conditions seem specific pain syndromes with a distinctive location in the eye or in the nose. We aimed to present a new prospective series in order to verify the consistency of these syndromes. We performed a descriptive study of all patients referred to our regional neurologic clinics from 2010 to 2014 because of facial pain exclusively felt in the eye or in the nose fulfilling the proposed diagnostic criteria for idiopathic ophthalmodynia and idiopathic rhinalgia. There were 9 patients with idiopathic ophthalmodynia and 7 patients with idiopathic rhinalgia, with a clear female preponderance, and a mean age at onset in the fifth decade. The pain was usually moderate and the temporal pattern was generally chronic. Only one patient reported accompaniments (hypersensitivity to the light and to the flow of air in the symptomatic eye). Preventive treatment with amitriptyline, pregabalin, or gabapentin was partially or totally effective. The clinical features of this new series parallels those of the original description, thus indicating that both idiopathic ophthalmodynia and idiopathic rhinalgia have clear-cut clinical pictures with excellent consistency both inter- and intra-individually. © 2015 American Headache Society.

Implementing quantum Ricci curvature

NASA Astrophysics Data System (ADS)

Klitgaard, N.; Loll, R.

2018-05-01

Quantum Ricci curvature has been introduced recently as a new, geometric observable characterizing the curvature properties of metric spaces, without the need for a smooth structure. Besides coordinate invariance, its key features are scalability, computability, and robustness. We demonstrate that these properties continue to hold in the context of nonperturbative quantum gravity, by evaluating the quantum Ricci curvature numerically in two-dimensional Euclidean quantum gravity, defined in terms of dynamical triangulations. Despite the well-known, highly nonclassical properties of the underlying quantum geometry, its Ricci curvature can be matched well to that of a five-dimensional round sphere.

Influence of Coanda surface curvature on performance of bladeless fan

NASA Astrophysics Data System (ADS)

Li, Guoqi; Hu, Yongjun; Jin, Yingzi; Setoguchi, Toshiaki; Kim, Heuy Dong

2014-10-01

The unique Coanda surface has a great influence on the performance of bladeless fan. However, there is few studies to explain the relationship between the performance and Coanda surface curvature at present. In order to gain a qualitative understanding of effect of the curvature on the performance of bladeless fan, numerical studies are performed in this paper. Firstly, three-dimensional numerical simulation is done by Fluent software. For the purpose to obtain detailed information of the flow field around the Coanda surface, two-dimensional numerical simulation is also conducted. Five types of Coanda surfaces with different curvature are designed, and the flow behaviour and the performance of them are analyzed and compared with those of the prototype. The analysis indicates that the curvature of Coanda surface is strongly related to blowing performance, It is found that there is an optimal curvature of Coanda surfaces among the studied models. Simulation result shows that there is a special low pressure region. With increasing curvature in Y direction, several low pressure regions gradually enlarged, then begin to merge slowly, and finally form a large area of low pressure. From the analyses of streamlines and velocity angle, it is found that the magnitude of the curvature affects the flow direction and reasonable curvature can induce fluid flow close to the wall. Thus, it leads to that the curvature of the streamlines is consistent with that of Coanda surface. Meanwhile, it also causes the fluid movement towards the most suitable direction. This study will provide useful information to performance improvements of bladeless fans.

Osteoporosis in men with idiopathic hypogonadotropic hypogonadism

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

Finkelstein, J.S.; Klibanski, A.; Neer, R.M.

To assess the effect of testosterone deficiency on skeletal integrity in men, we determined bone density in 23 hypogonadal men with isolated gonadotropin-releasing hormone deficiency and compared those values with ones from controls. Cortical bone density, as assessed by single-photon absorptiometry of the nondominant radius, ranged from 0.57 to 0.86 g/cm2 (mean +/- SE, 0.71 +/- 0.02) in patients with fused epiphyses and from 0.57 to 0.67 g/cm2 (mean, 0.61 +/- 0.01) in patients with open epiphyses, both of which were significantly (p less than 0.001) lower than normal. Spinal trabecular bone density, as assessed by computed tomography, was similarlymore » decreased (p less than 0.0001) and ranged from 42 to 177 mg K2HPO4/cm3 (mean, 112 +/- 7). Cortical bone density was at least 2 SD below normal in 16 of 23 men, and 8 men had spinal bone densities below the fracture threshold of 80 to 100 mg K2HPO4/cm3. Osteopenia was equally severe in men with immature and mature bone ages, suggesting that abnormal bone development plays an important role in the osteopenia of men with idiopathic hypogonadotropic hypogonadism.« less

The Effect of Spinal Tap Test on Different Sensory Modalities of Postural Stability in Idiopathic Normal Pressure Hydrocephalus.

PubMed

Abram, Katrin; Bohne, Silvia; Bublak, Peter; Karvouniari, Panagiota; Klingner, Carsten M; Witte, Otto W; Guntinas-Lichius, Orlando; Axer, Hubertus

2016-01-01

Postural instability in patients with normal pressure hydrocephalus (NPH) is a most crucial symptom leading to falls with secondary complications. The aim of the current study was to evaluate the therapeutic effect of spinal tap on postural stability in these patients. Seventeen patients with clinical symptoms of NPH were examined using gait scale, computerized dynamic posturography (CDP), and neuropsychological assessment. Examinations were done before and after spinal tap test. The gait score showed a significant improvement 24 h after spinal tap test in all subtests and in the sum score (p < 0.003), while neuropsychological assessment did not reveal significant differences 72 h after spinal tap test. CDP showed significant improvements after spinal tap test in the Sensory Organization Tests 2 (p = 0.017), 4 (p = 0.001), and 5 (p = 0.009) and the composite score (p = 0.01). Patients showed best performance in somatosensory and worst performance in vestibular dominated tests. Vestibular dominated tests did not improve significantly after spinal tap test, while somatosensory and visual dominated tests did. Postural stability in NPH is predominantly affected by deficient vestibular functions, which did not improve after spinal tap test. Conditions which improved best were mainly independent from visual control and are based on proprioceptive functions.

Obesity is a significant susceptibility factor for idiopathic AA amyloidosis.

PubMed

Blank, Norbert; Hegenbart, Ute; Dietrich, Sascha; Brune, Maik; Beimler, Jörg; Röcken, Christoph; Müller-Tidow, Carsten; Lorenz, Hanns-Martin; Schönland, Stefan O

2018-03-01

To investigate obesity as susceptibility factor in patients with idiopathic AA amyloidosis. Clinical, biochemical and genetic data were obtained from 146 patients with AA amyloidosis. Control groups comprised 40 patients with long-standing inflammatory diseases without AA amyloidosis and 56 controls without any inflammatory disease. Patients with AA amyloidosis had either familial Mediterranean fever (FMF) or long-standing rheumatic diseases as underlying inflammatory disease (n = 111, median age 46 years). However, in a significant proportion of patients with AA amyloidosis no primary disease was identified (idiopathic AA; n = 37, median age 60 years). Patients with idiopathic AA amyloidosis were more obese and older than patients with AA amyloidosis secondary to FMF or rheumatic diseases. Serum leptin levels correlated with the body mass index (BMI) in all types of AA amyloidosis. Elevated leptin levels of more than 30 µg/l were detected in 18% of FMF/rheumatic + AA amyloidosis and in 40% of patients with idiopathic AA amyloidosis (p = .018). Finally, the SAA1 polymorphism was confirmed as a susceptibility factor for AA amyloidosis irrespective of the type of the disease. Obesity, age and the SAA1 polymorphism are susceptibility factors for idiopathic AA amyloidosis. Recent advances in treatment of FMF and rheumatic disorders will decrease the incidence of AA amyloidosis due to these diseases. Idiopathic AA, however, might be an emerging problem in the ageing and increasingly obese population.

The influence of thermoplastic thoraco lumbo sacral orthoses on standing balance in subjects with idiopathic scoliosis.

PubMed

Khanal, Minoo; Arazpour, Mokhtar; Bahramizadeh, Mahmood; Samadian, Mohammad; Hutchins, Stephen W; Kashani, Reza Vahab; Mardani, Mohammad A; Tari, Hossein Vahid; Aboutorabi, Atefeh; Curran, Sarah; Sadeghi, Heidar

2016-08-01

Idiopathic scoliosis patients have postural equilibrium problems. The objective of this study was to assess postural control in subjects with idiopathic scoliosis following a 4-month intervention in an unbraced position. Quasi-experimental. Eight healthy girls and eight girls with idiopathic scoliosis took part. A Kistler force platform was used with a frequency of 100 Hz for recording data. The center of pressure was recorded in different positions out of brace for scoliosis and healthy subjects. Test conditions were single limb and double limb stance, with eyes open and closed, and foam and rigid surfaces. The data reflected a weak balance of idiopathic scoliosis subjects compared to healthy subjects. After 1 and 4 months of wearing the brace, center of pressure and center of gravity sway increased in the majority of the tests, although there were no significant differences in any of the test conditions (p > 0.05). While the center of pressure sway in medio-lateral direction decreased after 4 months of wearing a brace, in other variables center of pressure and center of gravity sway increased. Idiopathic scoliosis patients have weak balance in comparison to healthy subjects. In addition, following a period of 4 months of wearing a brace, balance parameters in the scoliosis subjects did not improve. The results show that we need more follow-up of orthoses wearing in idiopathic scoliosis subjects and suggest more studies at least 1-year follow-up to identify the efficiency of brace wear on balance. Scoliosis can alter postural stability and balance performance during quiet standing. Spinal deformity can alter a subject's ability to compensate for postural changes and cause gait deviations. This study investigated balance differences between the healthy and idiopathic scoliosis patients and the results of thoraco lumbo sacral orthosis brace wear. It might provide some new insight into the conservative treatment of idiopathic scoliosis patients for

Comparative Analysis of Interval, Skipped, and Key-vertebral Pedicle Screw Strategies for Correction in Patients With Lenke Type 1 Adolescent Idiopathic Scoliosis

PubMed Central

Wang, Fei; Xu, Xi-Ming; Lu, Yanghu; Wei, Xian-Zhao; Zhu, Xiao-Dong; Li, Ming

2016-01-01

Abstract Pedicle screw constructs have become the mainstay for surgical correction in patients with spinal deformities. To reduce or avoid the risk of pedicle screw-based complications and to decrease the costs associated with pedicle screw instrumentation, some authors have introduced interval, skipped, and key-vertebral pedicle screw strategies for correction. However, there have been no comparisons of outcomes among these 3 pedicle screw-placement strategies. The aim of this study was to compare the correlative clinical outcomes of posterior correction and fusion with pedicle screw fixation using these 3 surgical strategies. Fifty-six consecutive patients with Lenke type 1 adolescent idiopathic scoliosis were included in this study. Twenty patients were treated with the interval pedicle screw strategy (IPSS), 20 with the skipped pedicle screw strategy (SPSS), and 16 with the key-vertebral pedicle screw strategy (KVPSS). Coronal and sagittal radiographs were analyzed before surgery, at 1 week after surgery, and at the last follow-up after surgery. There were no significant differences among the 3 groups regarding preoperative radiographic parameters. No significant difference was found between the IPSS and SPSS groups in correction of the main thoracic curve (70.8% vs 70.0%; P = 0.524). However, there were statistically significant differences between the IPSS and KVPSS groups (70.8% vs 64.9%) and between the SPSS and KVPSS groups (70.0% vs 64.9%) in correction of the main thoracic curve (P < 0.001 for both). Additionally, there were no significant differences among the 3 strategies for sagittal parameters at the immediate postoperative and last postoperative follow-up periods, though there were significant differences in the Cobb angle between the preoperative and immediate postoperative periods among the 3 groups, but not between the immediate postoperative and last follow-up periods. The amount of hospital charges in the SPSS group was significantly

Sensitive zone parameters and curvature radius evaluation for polymer optical fiber curvature sensors

NASA Astrophysics Data System (ADS)

Leal-Junior, Arnaldo G.; Frizera, Anselmo; José Pontes, Maria

2018-03-01

Polymer optical fibers (POFs) are suitable for applications such as curvature sensors, strain, temperature, liquid level, among others. However, for enhancing sensitivity, many polymer optical fiber curvature sensors based on intensity variation require a lateral section. Lateral section length, depth, and surface roughness have great influence on the sensor sensitivity, hysteresis, and linearity. Moreover, the sensor curvature radius increase the stress on the fiber, which leads on variation of the sensor behavior. This paper presents the analysis relating the curvature radius and lateral section length, depth and surface roughness with the sensor sensitivity, hysteresis and linearity for a POF curvature sensor. Results show a strong correlation between the decision parameters behavior and the performance for sensor applications based on intensity variation. Furthermore, there is a trade-off among the sensitive zone length, depth, surface roughness, and curvature radius with the sensor desired performance parameters, which are minimum hysteresis, maximum sensitivity, and maximum linearity. The optimization of these parameters is applied to obtain a sensor with sensitivity of 20.9 mV/°, linearity of 0.9992 and hysteresis below 1%, which represent a better performance of the sensor when compared with the sensor without the optimization.

Reliability and concurrent validity of postural asymmetry measurement in adolescent idiopathic scoliosis

PubMed Central

Prowse, Ashleigh; Aslaksen, Berit; Kierkegaard, Marie; Furness, James; Gerdhem, Paul; Abbott, Allan

2017-01-01

AIM To investigate the reliability and concurrent validity of the Baseline® Body Level/Scoliosis meter for adolescent idiopathic scoliosis postural assessment in three anatomical planes. METHODS This is an observational reliability and concurrent validity study of adolescent referrals to the Orthopaedic department for scoliosis screening at Karolinska University Hospital, Stockholm, Sweden between March-May 2012. A total of 31 adolescents with idiopathic scoliosis (13.6 ± 0.6 years old) of mild-moderate curvatures (25° ± 12°) were consecutively recruited. Measurement of cervical, thoracic and lumbar curvatures, pelvic and shoulder tilt, and axial thoracic rotation (ATR) were performed by two trained physiotherapists in one day. The intraclass correlation coefficient (ICC) was used to determine the inter-examiner reliability (ICC2,1) and the intra-rater reliability (ICC3,3) of the Baseline® Body Level/Scoliosis meter. Spearman’s correlation analyses were used to estimate concurrent validity between the Baseline® Body Level/Scoliosis meter and Gold Standard Cobb angles from radiographs and the Orthopaedic Systems Inc. Scoliometer. RESULTS There was excellent reliability between examiners for thoracic kyphosis (ICC2,1 = 0.94), ATR (ICC2,1 = 0.92) and lumbar lordosis (ICC2,1 = 0.79). There was adequate reliability between examiners for cervical lordosis (ICC2,1 = 0.51), however poor reliability for pelvic and shoulder tilt. Both devices were reproducible in the measurement of ATR when repeated by one examiner (ICC3,3 0.98-1.00). The device had a good correlation with the Scoliometer (rho = 0.78). When compared with Cobb angle from radiographs, there was a moderate correlation for ATR (rho = 0.627). CONCLUSION The Baseline® Body Level/Scoliosis meter provides reliable transverse and sagittal cervical, thoracic and lumbar measurements and valid transverse plan measurements of mild-moderate scoliosis deformity. PMID:28144582

Reliability and concurrent validity of postural asymmetry measurement in adolescent idiopathic scoliosis.

PubMed

Prowse, Ashleigh; Aslaksen, Berit; Kierkegaard, Marie; Furness, James; Gerdhem, Paul; Abbott, Allan

2017-01-18

To investigate the reliability and concurrent validity of the Baseline ® Body Level/Scoliosis meter for adolescent idiopathic scoliosis postural assessment in three anatomical planes. This is an observational reliability and concurrent validity study of adolescent referrals to the Orthopaedic department for scoliosis screening at Karolinska University Hospital, Stockholm, Sweden between March-May 2012. A total of 31 adolescents with idiopathic scoliosis (13.6 ± 0.6 years old) of mild-moderate curvatures (25° ± 12°) were consecutively recruited. Measurement of cervical, thoracic and lumbar curvatures, pelvic and shoulder tilt, and axial thoracic rotation (ATR) were performed by two trained physiotherapists in one day. The intraclass correlation coefficient (ICC) was used to determine the inter-examiner reliability (ICC2,1) and the intra-rater reliability (ICC3,3) of the Baseline ® Body Level/Scoliosis meter. Spearman's correlation analyses were used to estimate concurrent validity between the Baseline ® Body Level/Scoliosis meter and Gold Standard Cobb angles from radiographs and the Orthopaedic Systems Inc. Scoliometer. There was excellent reliability between examiners for thoracic kyphosis (ICC2,1 = 0.94), ATR (ICC2,1 = 0.92) and lumbar lordosis (ICC2,1 = 0.79). There was adequate reliability between examiners for cervical lordosis (ICC2,1 = 0.51), however poor reliability for pelvic and shoulder tilt. Both devices were reproducible in the measurement of ATR when repeated by one examiner (ICC3,3 0.98-1.00). The device had a good correlation with the Scoliometer (rho = 0.78). When compared with Cobb angle from radiographs, there was a moderate correlation for ATR (rho = 0.627). The Baseline ® Body Level/Scoliosis meter provides reliable transverse and sagittal cervical, thoracic and lumbar measurements and valid transverse plan measurements of mild-moderate scoliosis deformity.

Cosmic curvature tested directly from observations

NASA Astrophysics Data System (ADS)

Denissenya, Mikhail; Linder, Eric V.; Shafieloo, Arman

2018-03-01

Cosmic spatial curvature is a fundamental geometric quantity of the Universe. We investigate a model independent, geometric approach to measure spatial curvature directly from observations, without any derivatives of data. This employs strong lensing time delays and supernova distance measurements to measure the curvature itself, rather than just testing consistency with flatness. We define two curvature estimators, with differing error propagation characteristics, that can crosscheck each other, and also show how they can be used to map the curvature in redshift slices, to test constancy of curvature as required by the Robertson-Walker metric. Simulating realizations of redshift distributions and distance measurements of lenses and sources, we estimate uncertainties on the curvature enabled by next generation measurements. The results indicate that the model independent methods, using only geometry without assuming forms for the energy density constituents, can determine the curvature at the ~6×10‑3 level.

Lateral Semicircular Canal Asymmetry in Idiopathic Scoliosis: An Early Link between Biomechanical, Hormonal and Neurosensory Theories?

PubMed Central

Hitier, Martin; Hamon, Michèle; Denise, Pierre; Lacoudre, Julien; Thenint, Marie-Aude; Mallet, Jean-François; Moreau, Sylvain; Quarck, Gaëlle

2015-01-01

Introduction Despite its high incidence and severe morbidity, the physiopathogenesis of adolescent idiopathic scoliosis (AIS) is still unknown. Here, we looked for early anomalies in AIS which are likely to be the cause of spinal deformity and could also be targeted by early treatments. We focused on the vestibular system, which is suspected of acting in AIS pathogenesis and which exhibits an end organ with size and shape fixed before birth. We hypothesize that, in adolescents with idiopathic scoliosis, vestibular morphological anomalies were already present at birth and could possibly have caused other abnormalities. Materials and Methods The vestibular organ of 18 adolescents with AIS and 9 controls were evaluated with MRI in a prospective case controlled study. We studied lateral semicircular canal orientation and the three semicircular canal positions relative to the midline. Lateral semicircular canal function was also evaluated by vestibulonystagmography after bithermal caloric stimulation. Results The left lateral semicircular canal was more vertical and further from the midline in AIS (p = 0.01) and these two parameters were highly correlated (r = -0.6; p = 0.02). These morphological anomalies were associated with functional anomalies in AIS (lower excitability, higher canal paresis), but were not significantly different from controls (p>0.05). Conclusion Adolescents with idiopathic scoliosis exhibit morphological vestibular asymmetry, probably determined well before birth. Since the vestibular system influences the vestibulospinal pathway, the hypothalamus, and the cerebellum, this indicates that the vestibular system is a possible cause of later morphological, hormonal and neurosensory anomalies observed in AIS. Moreover, the simple lateral SCC MRI measurement demonstrated here could be used for early detection of AIS, selection of children for close follow-up, and initiation of preventive treatment before spinal deformity occurs. PMID:26186348

Natural Curvature as Effective Confinement in Elastic Sheets

NASA Astrophysics Data System (ADS)

Albarran, Octavio; Katifori, Eleni; Goehring, Lucas

The wrinkling and folding transitions of thin elastic sheets have been extensively studied in the last decade. The exchange of energy from stretching to bending acts as a paradigm for a wide range of elastic instabilities, including the wrinkling of the gut, and the crinkling of leaves. In two dimensions this type of problem is typically considered by the model of an Euler-elastica in compressive confinement. We show that, even without any external forces, an elastic surface supported by a fluid can bend and wrinkle when it acquires a non-zero natural curvature. Locally, we will demonstrate how a preferential curvature can be related to an effective compression, and hence a confining force that can vary spatially. This suggests a simple experimental setup, where we have characterised a variety of wrinkle patterns that can be generated for different mechanical properties and natural curvatures.

CONTRAIS: CONservative TReatment for Adolescent Idiopathic Scoliosis: a randomised controlled trial protocol.

PubMed

Abbott, Allan; Möller, Hans; Gerdhem, Paul

2013-09-05

Idiopathic scoliosis is a three-dimensional structural deformity of the spine that occurs in children and adolescents. Recent reviews on bracing and exercise treatment have provided some evidence for effect of these interventions. The purpose of this study is to improve the evidence base regarding the effectiveness of conservative treatments for preventing curve progression in idiopathic scoliosis. Previously untreated girls and boys with idiopathic scoliosis, 9 to 17 years of age with at least one year of remaining growth and a curve Cobb angle of 25-40 degrees will be included. A total of 135 participants will be randomly allocated in groups of 45 patients each to receive one of the three interventions. All three groups will receive a physical activity prescription according to the World Health Organisation recommendations. One group will additionally wear a hyper-corrective night-time brace. One group will additionally perform postural scoliosis-specific exercises. Participation in the study will last until the curve has progressed, or until cessation of skeletal growth. OUTCOME variables will be measured every 6 months. The primary outcome variable, failure of treatment, is defined as progression of the Cobb angle more than 6 degrees, compared to the primary x-ray, seen on two consecutive spinal standing x-rays taken with 6 months interval. Secondary outcome measures include the SRS-22r and EQ5D-Y quality of life questionnaires, the International Physical Activity Questionnaire (IPAQ) short form, and Cobb angle at end of the study. This trial will evaluate which of the tested conservative treatment approaches that is the most effective for patients with adolescent idiopathic scoliosis. NCT01761305.

Intraspinal anomalies in early-onset idiopathic scoliosis.

PubMed

Pereira, E A C; Oxenham, M; Lam, K S

2017-06-01

In the United Kingdom, lower incidences of intraspinal abnormalities in patients with early onset idiopathic scoliosis have been observed than in studies in other countries. We aimed to determine the rates of these abnormalities in United Kingdom patients diagnosed with idiopathic scoliosis before the age of 11 years. This retrospective study of patients attending an urban scoliosis clinic identified 71 patients satisfying a criteria of: clinical diagnosis of idiopathic scoliosis; age of onset ten years and 11 months or less; MRI screening for intraspinal abnormalities. United Kingdom census data combined with patient referral data was used to calculate incidence. Mean age at diagnosis was six years with 39 right-sided and 32 left-sided curves. Four patients (5.6%) were found to have intraspinal abnormalities on MRI. These consisted of: two combined Arnold-Chiari type 1 malformations with syrinx; one syrinx with a low lying conus; and one isolated syrinx. Overall annual incidence of early onset idiopathic scoliosis was one out of 182 000 (0.0006%). This study reports the lowest rates to date of intraspinal anomalies in patients with early onset idiopathic scoliosis, adding to knowledge regarding current incidences of these abnormalities as well as any geographical variation in the nature of the disease. Cite this article: Bone Joint J 2017;99-B:829-33. ©2017 The British Editorial Society of Bone & Joint Surgery.

Different types of spinal afferent nerve endings in stomach and esophagus identified by anterograde tracing from dorsal root ganglia.

PubMed

Spencer, Nick J; Kyloh, Melinda; Beckett, Elizabeth A; Brookes, Simon; Hibberd, Tim

2016-10-15

In visceral organs of mammals, most noxious (painful) stimuli as well as innocuous stimuli are detected by spinal afferent neurons, whose cell bodies lie in dorsal root ganglia (DRGs). One of the major unresolved questions is the location, morphology, and neurochemistry of the nerve endings of spinal afferents that actually detect these stimuli in the viscera. In the upper gastrointestinal (GI) tract, there have been many anterograde tracing studies of vagal afferent endings, but none on spinal afferent endings. Recently, we developed a technique that now provides selective labeling of only spinal afferents. We used this approach to identify spinal afferent nerve endings in the upper GI tract of mice. Animals were anesthetized, and injections of dextran-amine were made into thoracic DRGs (T8-T12). Seven days post surgery, mice were euthanized, and the stomach and esophagus were removed, fixed, and stained for calcitonin gene-related peptide (CGRP). Spinal afferent axons were identified that ramified extensively through many rows of myenteric ganglia and formed nerve endings in discrete anatomical layers. Most commonly, intraganglionic varicose endings (IGVEs) were identified in myenteric ganglia of the stomach and varicose simple-type endings in the circular muscle and mucosa. Less commonly, nerve endings were identified in internodal strands, blood vessels, submucosal ganglia, and longitudinal muscle. In the esophagus, only IGVEs were identified in myenteric ganglia. No intraganglionic lamellar endings (IGLEs) were identified in the stomach or esophagus. We present the first identification of spinal afferent endings in the upper GI tract. Eight distinct types of spinal afferent endings were identified in the stomach, and most of them were CGRP immunoreactive. J. Comp. Neurol. 524:3064-3083, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Long-term Results of Ventral Penile Curvature Repair in Childhood.

PubMed

Golomb, Dor; Sivan, Bezalel; Livne, Pinhas M; Nevo, Amihay; Ben-Meir, David

2018-02-01

To assess the postpubertal outcome of ventral penile curvature repaired in infancy in terms of recurrence and aesthetics. Postpubertal patients treated for hypospadias and ventral penile curvature in infancy at a tertiary medical center were invited to undergo assessment of the quality of the repair. Findings were compared between patients with a straight penis after skin release and patients who required dorsal plication. The cohort included 27 patients of mean age 16.5 years who were reported with straight penis after surgery. Postpubertal curvature was found in 6 of 14 patients (43%) successfully treated by skin release and 10 of 13 patients (77%) who underwent dorsal plication (P = .087). Significant curvature (≥30 degrees) was found in 1 of 14 patients in the skin-release group and 4 of 13 in the dorsal plication group (P = .16). Rates of redo urethroplasty were 2 of 14 (14%) and 5 of 10 (50%), respectively. Patient satisfaction with the appearance of the penis did not differ significantly. Ventral penile curvature repaired in infancy often recurs after puberty. The need for dorsal plication has a trend-level association with recurrence of penile curvature in puberty. It might also be related to the degree of postpubertal penile curvature and the need for redo urethroplasty. Procedure type does not affect patient satisfaction with the postpubertal appearance of the penis. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaluation and management of adolescent idiopathic scoliosis: a review.

PubMed

Jada, Ajit; Mackel, Charles E; Hwang, Steven W; Samdani, Amer F; Stephen, James H; Bennett, James T; Baaj, Ali A

2017-10-01

Adolescent idiopathic scoliosis (AIS) is a 3D spinal deformity affecting children between the ages of 11 and 18, without an identifiable etiology. The authors here reviewed the available literature to provide spine surgeons with a summary and update on current management options. Smaller thoracic and thoracolumbar curves can be managed conservatively with observation or bracing, but corrective surgery may be indicated for rapidly growing or larger curves. The authors summarize the atypical features to look for in patients who may warrant further investigation with MRI during diagnosis and review the fundamental principles of the surgical management of AIS. Patients with AIS can be managed very well with a combination of conservative and surgical options. Outcomes for these children are excellent with sustained longer-term results.

Evidence of Cholesterol Accumulated in High Curvature Regions: Implication ot the Curvature Elastic Energy for Lipid Mixtures

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

Wang,W.; Yang, L.; Huang, H.

2007-01-01

Recent experiments suggested that cholesterol and other lipid components of high negative spontaneous curvature facilitate membrane fusion. This is taken as evidence supporting the stalk-pore model of membrane fusion in which the lipid bilayers go through intermediate structures of high curvature. How do the high-curvature lipid components lower the free energy of the curved structure? Do the high-curvature lipid components modify the average spontaneous curvature of the relevant monolayer, thereby facilitate its bending, or do the lipid components redistribute in the curved structure so as to lower the free energy? This question is fundamental to the curvature elastic energy formore » lipid mixtures. Here we investigate the lipid distribution in a monolayer of a binary lipid mixture before and after bending, or more precisely in the lamellar, hexagonal, and distorted hexagonal phases. The lipid mixture is composed of 2:1 ratio of brominated di18:0PC and cholesterol. Using a newly developed procedure for the multiwavelength anomalous diffraction method, we are able to isolate the bromine distribution and reconstruct the electron density distribution of the lipid mixture in the three phases. We found that the lipid distribution is homogenous and uniform in the lamellar and hexagonal phases. But in the distorted hexagonal phase, the lipid monolayer has nonuniform curvature, and cholesterol almost entirely concentrates in the high curvature region. This finding demonstrates that the association energies between lipid molecules vary with the curvature of membrane. Thus, lipid components in a mixture may redistribute under conditions of nonuniform curvature, such as in the stalk structure. In such cases, the spontaneous curvature depends on the local lipid composition and the free energy minimum is determined by lipid distribution as well as curvature.« less

Symptomatic thoracic spinal cord herniation: case series and technical report.

PubMed

Hawasli, Ammar H; Ray, Wilson Z; Wright, Neill M

2014-09-01

Idiopathic spinal cord herniation (ISCH) is an uncommon condition located predominantly in the thoracic spine and often associated with a remote history of a major traumatic injury. ISCH has an incompletely described presentation and unknown etiology. There is no consensus on the treatment algorithm and surgical technique, and there are few data on clinical outcomes. In this case series and technical report, we describe the atypical myelopathy presentation, remote history of traumatic injury, radiographic progression, treatment, and outcomes of 5 patients treated at Washington University for symptomatic ISCH. A video showing surgical repair is presented. In contrast to classic compressive myelopathy symptomatology, ISCH patients presented with an atypical myelopathy, characterized by asymmetric motor and sensory deficits and early-onset urinary incontinence. Clinical deterioration correlated with progressive spinal cord displacement and herniation observed on yearly spinal imaging in a patient imaged serially because of multiple sclerosis. Finally, compared with compressive myelopathy in the thoracic spine, surgical treatment of ISCH led to rapid improvement despite a long duration of symptoms. Symptomatic ISCH presents with atypical myelopathy and slow temporal progression and can be successfully managed with surgical repair.

Symptomatic Thoracic Spinal Cord Herniation: Case Series and Technical Report

PubMed Central

Hawasli, Ammar H.; Ray, Wilson Z.; Wright, Neill M.

2014-01-01

Background and Importance Idiopathic spinal cord herniation (ISCH) is an uncommon condition located predominantly in the thoracic spine and often associated with a remote history of a major traumatic injury. ISCH has an incompletely described presentation and unknown etiology. There is no consensus on treatment algorithm and surgical technique, and there is little data on clinical outcomes. Clinical Presentation In this case series and technical report, we describe the atypical myelopathy presentation, remote history of traumatic injury, radiographic progression, treatment, and outcomes of 5 patients treated at Washington University for symptomatic ISCH. A video showing surgical repair is presented. In contrast to classic compressive myelopathy symptomology, ISCH patients presented with an atypical myelopathy, characterized by asymmetric motor and sensory deficits and early-onset urinary incontinence. Clinical deterioration correlated with progressive spinal cord displacement and herniation observed on yearly spinal imaging in a patient imaged serially due to multiple sclerosis. Finally compared to compressive myelopathy in the thoracic spine, surgical treatment of ISH led to rapid improvement despite long duration of symptoms. Conclusion Symptomatic ISCH presents with atypical myelopathy and slow temporal progression and can be successfully managed with surgical repair. PMID:24871148

From voxel to curvature

NASA Astrophysics Data System (ADS)

Monga, Olivier; Ayache, Nicholas; Sander, Peter T.

1991-09-01

Modern medical image techniques, such as magnetic resonance image (MRI) or x-ray computed tomography provide three dimensional images of internal structures of the body, usually by means of a stack of tomographic images. The first stage in the automatic analysis of such data is 3-D edge detection1,2 which provides points corresponding to the boundaries of the surfaces forming the 3-D structure. The next stage is to characterize the local geometry of these surfaces in order to extract points or lines on which registration and/or tracking procedures can rely.3,4,5,6 This paper presents a pipeline of processes which define a hierarchical description of the second order differential characteristics of the surfaces. The focus is on the theoretical coherence of these levels of representation. Using uncertainty, a link is established between the edge detection and the local surface approximation by addressing the uncertainties inherent to edge detection in 2-D or 3-D images; and how to incorporate these uncertainties into the computation of local geometric models. In particular, calculate the uncertainty of edge location, direction, and magnitude for the 3-D Deriche operator is calculated.1,2 Statistical results are then used as a solid theoretical foundation on which to base subsequent computations, such as the determination of local surface curvature using local geometric models for surface segmentation. From the local fitting, for each edge point the mean and Gaussian curvature, principal curvatures and directions, curvature singularities, lines of curvature singularities, and covariance matrices defining the uncertainties are calculated. Experimental results for real data using two 3-D scanner images of the same organ taken at different positions demonstrate the stability of the mean and Gaussian curvatures. Experimental results for real data showing the determination of local curvature extremes of surfaces extracted from MR images are presented.

Model-independent Constraints on Cosmic Curvature and Opacity

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

Wang, Guo-Jian; Li, Zheng-Xiang; Xia, Jun-Qing

2017-09-20

In this paper, we propose to estimate the spatial curvature of the universe and the cosmic opacity in a model-independent way with expansion rate measurements, H ( z ), and type Ia supernova (SNe Ia). On the one hand, using a nonparametric smoothing method Gaussian process, we reconstruct a function H ( z ) from opacity-free expansion rate measurements. Then, we integrate the H ( z ) to obtain distance modulus μ {sub H}, which is dependent on the cosmic curvature. On the other hand, distances of SNe Ia can be determined by their photometric observations and thus are opacity-dependent.more » In our analysis, by confronting distance moduli μ {sub H} with those obtained from SNe Ia, we achieve estimations for both the spatial curvature and the cosmic opacity without any assumptions for the cosmological model. Here, it should be noted that light curve fitting parameters, accounting for the distance estimation of SNe Ia, are determined in a global fit together with the cosmic opacity and spatial curvature to get rid of the dependence of these parameters on cosmology. In addition, we also investigate whether the inclusion of different priors for the present expansion rate ( H {sub 0}: global estimation, 67.74 ± 0.46 km s{sup −1} Mpc{sup −1}, and local measurement, 73.24 ± 1.74 km s{sup −1} Mpc{sup −1}) exert influence on the reconstructed H ( z ) and the following estimations of the spatial curvature and cosmic opacity. Results show that, in general, a spatially flat and transparent universe is preferred by the observations. Moreover, it is suggested that priors for H {sub 0} matter a lot. Finally, we find that there is a strong degeneracy between the curvature and the opacity.« less

Electrophysiological characterization of spinal neurons in different models of diabetes type 1- and type 2-induced neuropathy in rats.

PubMed

Schuelert, N; Gorodetskaya, N; Just, S; Doods, H; Corradini, L

2015-04-16

Diabetic polyneuropathy (DPN) is a devastating complication of diabetes. The underlying pathogenesis of DPN is still elusive and an effective treatment devoid of side effects presents a challenge. There is evidence that in type-1 and -2 diabetes, metabolic and morphological changes lead to peripheral nerve damage and altered central nociceptive transmission, which may contribute to neuropathic pain symptoms. We characterized the electrophysiological response properties of spinal wide dynamic range (WDR) neurons in three diabetic models. The streptozotocin (STZ) model was used as a drug-induced model of type-1 diabetes, and the BioBreeding/Worcester (BB/Wor) and Zucker diabetic fatty (ZDF) rat models were used for genetic DPN models. Data were compared to the respective control group (BB/Wor diabetic-resistant, Zucker lean (ZL) and saline-injected Wistar rat). Response properties of WDR neurons to mechanical stimulation and spontaneous activity were assessed. We found abnormal response properties of spinal WDR neurons in all diabetic rats but not controls. Profound differences between models were observed. In BB/Wor diabetic rats evoked responses were increased, while in ZDF rats spontaneous activity was increased and in STZ rats mainly after discharges were increased. The abnormal response properties of neurons might indicate differential pathological, diabetes-induced, changes in spinal neuronal transmission. This study shows for the first time that specific electrophysiological response properties are characteristic for certain models of DPN and that these might reflect the diverse and complex symptomatology of DPN in the clinic. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Local curvature measurements of a lean, partially premixed swirl-stabilised flame

NASA Astrophysics Data System (ADS)

Bayley, Alan E.; Hardalupas, Yannis; Taylor, Alex M. K. P.

2012-04-01

A swirl-stabilised, lean, partially premixed combustor operating at atmospheric conditions has been used to investigate the local curvature distributions in lifted, stable and thermoacoustically oscillating CH4-air partially premixed flames for bulk cold-flow Reynolds numbers of 15,000 and 23,000. Single-shot OH planar laser-induced fluorescence has been used to capture instantaneous images of these three different flame types. Use of binary thresholding to identify the reactant and product regions in the OH planar laser-induced fluorescence images, in order to extract accurate flame-front locations, is shown to be unsatisfactory for the examined flames. The Canny-Deriche edge detection filter has also been examined and is seen to still leave an unacceptable quantity of artificial flame-fronts. A novel approach has been developed for image analysis where a combination of a non-linear diffusion filter, Sobel gradient and threshold-based curve elimination routines have been used to extract traces of the flame-front to obtain local curvature distributions. A visual comparison of the effectiveness of flame-front identification is made between the novel approach, the threshold binarisation filter and the Canny-Deriche filter. The novel approach appears to most accurately identify the flame-fronts. Example histograms of the curvature for six flame conditions and of the total image area are presented and are found to have a broader range of local flame curvatures for increasing bulk Reynolds numbers. Significantly positive values of mean curvature and marginally positive values of skewness of the histogram have been measured for one lifted flame case, but this is generally accounted for by the effect of flame brush curvature. The mean local flame-front curvature reduces with increasing axial distance from the burner exit plane for all flame types. These changes are more pronounced in the lifted flames but are marginal for the thermoacoustically oscillating flames. It is

Curvature-Induced Instabilities of Shells

NASA Astrophysics Data System (ADS)

Pezzulla, Matteo; Stoop, Norbert; Steranka, Mark P.; Bade, Abdikhalaq J.; Holmes, Douglas P.

2018-01-01

Induced by proteins within the cell membrane or by differential growth, heating, or swelling, spontaneous curvatures can drastically affect the morphology of thin bodies and induce mechanical instabilities. Yet, the interaction of spontaneous curvature and geometric frustration in curved shells remains poorly understood. Via a combination of precision experiments on elastomeric spherical shells, simulations, and theory, we show how a spontaneous curvature induces a rotational symmetry-breaking buckling as well as a snapping instability reminiscent of the Venus fly trap closure mechanism. The instabilities, and their dependence on geometry, are rationalized by reducing the spontaneous curvature to an effective mechanical load. This formulation reveals a combined pressurelike term in the bulk and a torquelike term in the boundary, allowing scaling predictions for the instabilities that are in excellent agreement with experiments and simulations. Moreover, the effective pressure analogy suggests a curvature-induced subcritical buckling in closed shells. We determine the critical buckling curvature via a linear stability analysis that accounts for the combination of residual membrane and bending stresses. The prominent role of geometry in our findings suggests the applicability of the results over a wide range of scales.

Spinal muscular atrophy

MedlinePlus

... and tendons and abnormal curvature of the spine ( scoliosis ). Bracing may be needed. Surgery may be needed to correct skeletal deformities, such as scoliosis. Outlook (Prognosis) Children with SMA type I rarely ...

x-y curvature wavefront sensor.

PubMed

Cagigal, Manuel P; Valle, Pedro J

2015-04-15

In this Letter, we propose a new curvature wavefront sensor based on the principles of optical differentiation. The theoretically modeled setup consists of a diffractive optical mask placed at the intermediate plane of a classical two-lens coherent optical processor. The resulting image is composed of a number of local derivatives of the entrance pupil function whose proper combination provides the wavefront curvature. In contrast to the common radial curvature sensors, this one is able to provide the x and y wavefront curvature maps simultaneously. The sensor offers other additional advantages like having high spatial resolution, adjustable dynamic range, and not being sensitive to misalignment.

Cervical lordotic alignment following posterior spinal fusion for adolescent idiopathic scoliosis: reciprocal changes and risk factors for malalignment.

PubMed

Hayashi, Kazunori; Toyoda, Hiromitsu; Terai, Hidetomi; Suzuki, Akinobu; Hoshino, Masatoshi; Tamai, Koji; Ohyama, Shoichiro; Nakamura, Hiroaki

2017-04-01

OBJECTIVE Numerous reports have been published on the effectiveness and safety of correction of the coronal Cobb angle and thoracolumbar sagittal alignment in patients with adolescent idiopathic scoliosis (AIS). Suboptimal sagittal alignment, such as decreased thoracic kyphosis (TK), after corrective surgery, is a possible cause of lumbar or cervical spinal degeneration and junctional malalignment; however, few reports are available on reciprocal changes outside of the fused segments, such as the cervical lordotic angle (CLA). This study aimed to investigate the relationship between the perioperative CLA and other radiographic factors or clinical results in AIS, and to identify independent risk factors of postoperative cervical hyperkyphosis. METHODS A total of 51 AIS patients who underwent posterior spinal fusion with the placement of pedicle screw (PS) constructs at thoracic levels were included in the study. Clinical and radiographic follow-up of patients was conducted for a minimum of 2 years, and the postoperative course was evaluated. The authors measured and identified the changes in the CLA and other radiographic parameters using whole-spine radiography, with the patient in the standing position, performed immediately before surgery, 2 weeks after surgery, and 2 years after surgery. The postoperative cervical hyperkyphosis group included patients whose CLA at 2-year follow-up was smaller than -10°. The reciprocal changes of the CLA and other parameters were also investigated. Univariate and multivariate analyses were conducted to determine the associated risk factors for postoperative cervical hyperkyphosis. RESULTS This study comprised 48 females and 3 males (mean age 16.0 years). The mean follow-up period was 47 months (range 24-90 months). The main coronal thoracic curve was corrected from 54.6° to 16.4°, and the mean correction rate was 69.8% at 2 years. The CLA significantly increased from the mean preoperative measurement (-5.4° ± 14°) to the 2

Biomechanics of phalangeal curvature.

PubMed

Richmond, Brian G

2007-12-01

Phalangeal curvature has been widely cited in primate functional morphology and is one of the key traits in the ongoing debate about whether the locomotion of early hominins included a significant degree of arboreality. This study examines the biomechanics of phalangeal curvature using data on hand posture, muscle recruitment, and anatomical moment arms to develop a finite element (FE) model of a siamang manual proximal phalanx during suspensory grasping. Strain patterns from experiments on intact cadaver forelimbs validated the model. The strain distribution in the curved siamang phalanx FE model was compared to that in a mathematically straight rendition in order to test the hypotheses that curvature: 1) reduces strain and 2) results in lower bending strains but relatively higher compression. In the suspensory posture, joint reaction forces load the articular ends of the phalanx in compression and dorsally, while muscle forces acting through the flexor sheath pull the mid-shaft palmarly. These forces compress the phalanx dorsally and tense it palmarly, effectively bending it 'open.' Strains in the curved model were roughly half that of the straight model despite equivalent lengths, areas, mechanical properties, and loading conditions in the two models. The curved model also experienced a higher ratio of compressive to tensile strains. Curvature reduces strains during grasping hand postures because the curved bone is more closely aligned with the joint reaction forces. Therefore, phalangeal curvature reduces the strains associated with arboreal, and especially suspensory, activity involving flexed digits. These results offer a biomechanical explanation for the observed association between phalangeal curvature and arboreality.

A novel spinal kinematic analysis using X-ray imaging and vicon motion analysis: a case study.

PubMed

Noh, Dong K; Lee, Nam G; You, Joshua H

2014-01-01

This study highlights a novel spinal kinematic analysis method and the feasibility of X-ray imaging measurements to accurately assess thoracic spine motion. The advanced X-ray Nash-Moe method and analysis were used to compute the segmental range of motion in thoracic vertebra pedicles in vivo. This Nash-Moe X-ray imaging method was compared with a standardized method using the Vicon 3-dimensional motion capture system. Linear regression analysis showed an excellent and significant correlation between the two methods (R2 = 0.99, p < 0.05), suggesting that the analysis of spinal segmental range of motion using X-ray imaging measurements was accurate and comparable to the conventional 3-dimensional motion analysis system. Clinically, this novel finding is compelling evidence demonstrating that measurements with X-ray imaging are useful to accurately decipher pathological spinal alignment and movement impairments in idiopathic scoliosis (IS).

CONTRAIS: CONservative TReatment for Adolescent Idiopathic Scoliosis: a randomised controlled trial protocol

PubMed Central

2013-01-01

Background Idiopathic scoliosis is a three-dimensional structural deformity of the spine that occurs in children and adolescents. Recent reviews on bracing and exercise treatment have provided some evidence for effect of these interventions. The purpose of this study is to improve the evidence base regarding the effectiveness of conservative treatments for preventing curve progression in idiopathic scoliosis. Methods/design Patients: Previously untreated girls and boys with idiopathic scoliosis, 9 to 17 years of age with at least one year of remaining growth and a curve Cobb angle of 25–40 degrees will be included. A total of 135 participants will be randomly allocated in groups of 45 patients each to receive one of the three interventions. Interventions: All three groups will receive a physical activity prescription according to the World Health Organisation recommendations. One group will additionally wear a hyper-corrective night-time brace. One group will additionally perform postural scoliosis-specific exercises. Outcome: Participation in the study will last until the curve has progressed, or until cessation of skeletal growth. Outcome variables will be measured every 6 months. The primary outcome variable, failure of treatment, is defined as progression of the Cobb angle more than 6 degrees, compared to the primary x-ray, seen on two consecutive spinal standing x-rays taken with 6 months interval. Secondary outcome measures include the SRS-22r and EQ5D-Y quality of life questionnaires, the International Physical Activity Questionnaire (IPAQ) short form, and Cobb angle at end of the study. Discussion This trial will evaluate which of the tested conservative treatment approaches that is the most effective for patients with adolescent idiopathic scoliosis. Trial registration NCT01761305 PMID:24007599

Juvenile Idiopathic Arthritis

MedlinePlus

... Is Juvenile Idiopathic Arthritis the same as Juvenile Rheumatoid Arthritis? Yes, Juvenile Idiopathic Arthritis (JIA) is a new ... of chronic inflammatory diseases that affect children. Juvenile Rheumatoid Arthritis (JRA) is the older term that was used ...

Determining wave direction using curvature parameters.

PubMed

de Queiroz, Eduardo Vitarelli; de Carvalho, João Luiz Baptista

2016-01-01

The curvature of the sea wave was tested as a parameter for estimating wave direction in the search for better results in estimates of wave direction in shallow waters, where waves of different sizes, frequencies and directions intersect and it is difficult to characterize. We used numerical simulations of the sea surface to determine wave direction calculated from the curvature of the waves. Using 1000 numerical simulations, the statistical variability of the wave direction was determined. The results showed good performance by the curvature parameter for estimating wave direction. Accuracy in the estimates was improved by including wave slope parameters in addition to curvature. The results indicate that the curvature is a promising technique to estimate wave directions.•In this study, the accuracy and precision of curvature parameters to measure wave direction are analyzed using a model simulation that generates 1000 wave records with directional resolution.•The model allows the simultaneous simulation of time-series wave properties such as sea surface elevation, slope and curvature and they were used to analyze the variability of estimated directions.•The simultaneous acquisition of slope and curvature parameters can contribute to estimates wave direction, thus increasing accuracy and precision of results.

Idiopathic Intracranial Hypertension (Pseudotumor Cerebri)

MedlinePlus

... Asked Questions Español Condiciones Chinese Conditions Idiopathic Intracranial Hypertension (Pseudotumor Cerebri) En Español Read in Chinese What is idiopathic intracranial hypertension? Idiopathic intracranial hypertension (IIH) is a disorder that ...

EAU guidelines on penile curvature.

PubMed

Hatzimouratidis, Konstantinos; Eardley, Ian; Giuliano, François; Hatzichristou, Dimitrios; Moncada, Ignacio; Salonia, Andrea; Vardi, Yoram; Wespes, Eric

2012-09-01

Penile curvature can be congenital or acquired. Acquired curvature is secondary due to La Peyronie (Peyronie's) disease. To provide clinical guidelines on the diagnosis and treatment of penile curvature. A systematic literature search on the epidemiology, diagnosis, and treatment of penile curvature was performed. Articles with the highest evidence available were selected and formed the basis for assigning levels of evidence and grades of recommendations. The pathogenesis of congenital penile curvature is unknown. Peyronie's disease is a poorly understood connective tissue disorder most commonly attributed to repetitive microvascular injury or trauma during intercourse. Diagnosis is based on medical and sexual histories, which are sufficient to establish the diagnosis. Physical examination includes assessment of palpable nodules and penile length. Curvature is best documented by a self-photograph or pharmacologically induced erection. The only treatment option for congenital penile curvature is surgery based on plication techniques. Conservative treatment for Peyronie's disease is associated with poor outcomes. Pharmacotherapy includes oral potassium para-aminobenzoate, intralesional treatment with verapamil, clostridial collagenase or interferon, topical verapamil gel, and iontophoresis with verapamil and dexamethasone. They can be efficacious in some patients, but none of these options carry a grade A recommendation. Steroids, vitamin E, and tamoxifen cannot be recommended. Extracorporeal shock wave treatment and penile traction devices may only be used to treat penile pain and reduce penile deformity, respectively. Surgery is indicated when Peyronie's disease is stable for at least 3 mo. Tunical shortening procedures, especially plication techniques, are the first treatment options. Tunical lengthening procedures are preferred in more severe curvatures or in complex deformities. Penile prosthesis implantation is recommended in patients with erectile dysfunction

Stretchable Dual-Capacitor Multi-Sensor for Touch-Curvature-Pressure-Strain Sensing.

PubMed

Jin, Hanbyul; Jung, Sungchul; Kim, Junhyung; Heo, Sanghyun; Lim, Jaeik; Park, Wonsang; Chu, Hye Yong; Bien, Franklin; Park, Kibog

2017-09-07

We introduce a new type of multi-functional capacitive sensor that can sense several different external stimuli. It is fabricated only with polydimethylsiloxane (PDMS) films and silver nanowire electrodes by using selective oxygen plasma treatment method without photolithography and etching processes. Differently from the conventional single-capacitor multi-functional sensors, our new multi-functional sensor is composed of two vertically-stacked capacitors (dual-capacitor). The unique dual-capacitor structure can detect the type and strength of external stimuli including curvature, pressure, strain, and touch with clear distinction, and it can also detect the surface-normal directionality of curvature, pressure, and touch. Meanwhile, the conventional single-capacitor sensor has ambiguity in distinguishing curvature and pressure and it can detect only the strength of external stimulus. The type, directionality, and strength of external stimulus can be determined based on the relative capacitance changes of the two stacked capacitors. Additionally, the logical flow reflected on a tree structure with its branches reaching the direction and strength of the corresponding external stimulus unambiguously is devised. This logical flow can be readily implemented in the sensor driving circuit if the dual-capacitor sensor is commercialized actually in the future.

The current status of bracing for patients with adolescent idiopathic scoliosis.

PubMed

Stokes, O M; Luk, K D K

2013-10-01

Adolescent idiopathic scoliosis affects about 3% of children. Non-operative measures are aimed at altering the natural history to maintain the size of the curve below 40° at skeletal maturity. The application of braces to treat spinal deformity pre-dates the era of evidence-based medicine, and there is a paucity of irrefutable prospective evidence in the literature to support their use and their effectiveness has been questioned. This review considers this evidence. The weight of the evidence is in favour of bracing over observation. The most recent literature has moved away from addressing this question, and instead focuses on developments in the design of braces and ways to improve compliance.

Juvenile idiopathic arthritis.

PubMed

Boros, Christina; Whitehead, Ben

2010-09-01

Juvenile idiopathic arthritis is the most common rheumatic disease in childhood, occurring in approximately 1:500 children. Despite a recent expansion in treatment options and improvement of outcomes, significant morbidity still occurs. This article outlines the clinical manifestations, assessment, detection of complications, treatment options and monitoring requirements, with the aid of guidelines recently published by The Royal Australian College of General Practitioners, which provide practical support for general practitioners to ensure best practice care and to prevent lifelong disability in patients with juvenile idiopathic arthritis. General practice plays an important role in the early detection, initial management and ongoing monitoring of children with juvenile idiopathic arthritis. Early detection involves understanding the classification framework for subtypes of juvenile idiopathic arthritis, and being aware of the clinical manifestations and how to look for them, through history, examination and appropriate investigation. The major extra-articular manifestations of juvenile idiopathic arthritis are uveitis and growth disturbance. Treatment options include nonsteroidal anti-inflammatory drugs, methotrexate, biologic agents, and corticosteroids. Management using a multidisciplinary approach can prevent long term sequelae. Unfortunately, approximately 50% of children will have active disease as adults.

Spinal Disinhibition in Experimental and Clinical Painful Diabetic Neuropathy

PubMed Central

Marshall, Andrew G.; Lee-Kubli, Corinne; Azmi, Shazli; Zhang, Michael; Ferdousi, Maryam; Mixcoatl-Zecuatl, Teresa; Petropoulos, Ioannis N.; Ponirakis, Georgios; Fineman, Mark S.; Fadavi, Hassan; Frizzi, Katie; Tavakoli, Mitra; Jolivalt, Corinne G.; Boulton, Andrew J.M.; Efron, Nathan; Calcutt, Nigel A.

2017-01-01

Impaired rate-dependent depression (RDD) of the Hoffman reflex is associated with reduced dorsal spinal cord potassium chloride cotransporter expression and impaired spinal γ-aminobutyric acid type A receptor function, indicative of spinal inhibitory dysfunction. We have investigated the pathogenesis of impaired RDD in diabetic rodents exhibiting features of painful neuropathy and the translational potential of this marker of spinal inhibitory dysfunction in human painful diabetic neuropathy. Impaired RDD and allodynia were present in type 1 and type 2 diabetic rats but not in rats with type 1 diabetes receiving insulin supplementation that did not restore normoglycemia. Impaired RDD in diabetic rats was rapidly normalized by spinal delivery of duloxetine acting via 5-hydroxytryptamine type 2A receptors and temporally coincident with the alleviation of allodynia. Deficits in RDD and corneal nerve density were demonstrated in patients with painful diabetic neuropathy compared with healthy control subjects and patients with painless diabetic neuropathy. Spinal inhibitory dysfunction and peripheral small fiber pathology may contribute to the clinical phenotype in painful diabetic neuropathy. Deficits in RDD may help identify patients with spinally mediated painful diabetic neuropathy who may respond optimally to therapies such as duloxetine. PMID:28202580

Curvature bound from gravitational catalysis

NASA Astrophysics Data System (ADS)

Gies, Holger; Martini, Riccardo

2018-04-01

We determine bounds on the curvature of local patches of spacetime from the requirement of intact long-range chiral symmetry. The bounds arise from a scale-dependent analysis of gravitational catalysis and its influence on the effective potential for the chiral order parameter, as induced by fermionic fluctuations on a curved spacetime with local hyperbolic properties. The bound is expressed in terms of the local curvature scalar measured in units of a gauge-invariant coarse-graining scale. We argue that any effective field theory of quantum gravity obeying this curvature bound is safe from chiral symmetry breaking through gravitational catalysis and thus compatible with the simultaneous existence of chiral fermions in the low-energy spectrum. With increasing number of dimensions, the curvature bound in terms of the hyperbolic scale parameter becomes stronger. Applying the curvature bound to the asymptotic safety scenario for quantum gravity in four spacetime dimensions translates into bounds on the matter content of particle physics models.

Comparison Of Pre-Operative Curvature With Postoperative Curvature In Root Canals Treated With K-3 Rotary Systems.

PubMed

Nagi, Sana Ehsen; Khan, Farhan Raza

2017-01-01

With root canal treatment, the organic debris and micro-organisms from pulp space is removed and an ideal canal preparation is achieved that is conducive of hermetic obturation. The purpose of this study was to correlate the pre-operative canal curvature with the postoperative curvature in human extracted teeth prepared with K-3 rotary systems. The root canal preparation was carried out on extracted human molars and premolars using K-3 endodontic rotary files. A pre and post-operative image of the teeth using digital radiograph were taken in order to compare pre and post-operative canal curvature. The images were saved in an images retrieval system (Gendex software, USA). Change in the canal curvature was measured using the software measuring tool (Vixwin software, USA). Student paired t-test and Pearson correlation test was applied at 0.05 level of significance. There is a statistically significant difference between pre-operative and post-operative canal curvature (p-value <0.001) and a strong positive correlation (91% correlation) between pre-operative and post-operative canal curvature in teeth prepared with the K-3 rotary files. A significant difference between pre and post instrumentation curvature was found. Degree of canal curvature was not correlated with time taken for canal preparation.

Curvature capillary migration of microspheres.

PubMed

Sharifi-Mood, Nima; Liu, Iris B; Stebe, Kathleen J

2015-09-14

We address the question: how does capillarity propel microspheres along curvature gradients? For a particle on a fluid interface, there are two conditions that can apply at the three phase contact line: either the contact line adopts an equilibrium contact angle, or it can be pinned by kinetic trapping, e.g. at chemical heterogeneities, asperities, or other pinning sites on the particle surface. We formulate the curvature capillary energy for both scenarios for particles smaller than the capillary length and far from any pinning boundaries. The scale and range of the distortion made by the particle are set by the particle radius; we use singular perturbation methods to find the distortions and to rigorously evaluate the associated capillary energies. For particles with equilibrium contact angles, contrary to the literature, we find that the capillary energy is negligible, with the first contribution bounded to fourth order in the product of the particle radius and the deviatoric curvature of the host interface. For pinned contact lines, we find curvature capillary energies that are finite, with a functional form investigated previously by us for disks and microcylinders on curved interfaces. In experiments, we show microspheres migrate along deterministic trajectories toward regions of maximum deviatoric curvature with curvature capillary energies ranging from 6 × 10(3)-5 × 10(4)kBT. These data agree with the curvature capillary energy for the case of pinned contact lines. The underlying physics of this migration is a coupling of the interface deviatoric curvature with the quadrupolar mode of nanometric disturbances in the interface owing to the particle's contact line undulations. This work is an example of the major implications of nanometric roughness and contact line pinning for colloidal dynamics.

Etiological Theories of Adolescent Idiopathic Scoliosis: Past and Present

PubMed Central

Fadzan, Maja; Bettany-Saltikov, Josette

2017-01-01

Adolescent idiopathic scoliosis is one of the most common spinal deformities, yet its cause is unknown. Various theories look to biomechanical, neuromuscular, genetic, and environmental origins, yet our understanding of scoliosis etiology is still limited. Determining the cause of a disease is crucial to developing the most effective treatment. Associations made with scoliosis do not necessarily point to causality, and it is difficult to determine whether said associations are primary (playing a role in development) or secondary (develop as a result of scoliosis). Scoliosis is a complex condition with highly variable expression, even among family members, and likely has many causes. These causes could be similar among homogenous groups of AIS patients, or they could be individual. Here, we review the most prevalent theories of scoliosis etiology and recent trends in research. PMID:29399224

Genetic (idiopathic) epilepsy with photosensitive seizures includes features of both focal and generalized seizures.

PubMed

Xue, Jiao; Gong, Pan; Yang, Haipo; Liu, Xiaoyan; Jiang, Yuwu; Zhang, Yuehua; Yang, Zhixian

2018-04-19

Clinically, some patients having genetic (idiopathic) epilepsy with photosensitive seizures were difficult to be diagnosed. We aimed to discuss whether the genetic (idiopathic) epilepsy with photosensitive seizures is a focal entity, a generalized entity or a continuum. Twenty-two patients with idiopathic epilepsies and photoconvulsive response (PCR) were retrospectively recruited. In the medical records, the seizure types included "generalized tonic-clonic seizures (GTCS)" in 15, "partial secondarily GTCS (PGTCS)" in 3, partial seizures (PS) in 3, myoclonic seizures in 2, eyelid myoclonus in one, and only febrile seizures in one. Seizure types of PCR included GTCS (1/22), PGTCS (6/22), PS (9/22), electrical seizures (ES) (3/22) and GTCS/PGTCS (3/22). Combined the medical history with PCR results, they were diagnosed as: idiopathic (photosensitive) occipital lobe epilepsy (I(P)OE) in 12, genetic (idiopathic) generalized epilepsy (GGE) in one, GGE/I(P)OE in 5, pure photosensitive seizure in one, and epilepsy with undetermined generalized or focal seizure in 3. So, the dichotomy between generalized and focal seizures might have been out of date regarding to pathophysiological advances in epileptology. To some extent, it would be better to recognize the idiopathic epilepsy with photosensitive seizures as a continuum between focal and generalized seizures.

Can Intraoperative Text Messages Reduce Parental Anxiety of Children Undergoing Posterior Spinal Fusion Surgery for Adolescent Idiopathic Scoliosis?

PubMed

Kwan, Mun Keong; Chiu, Chee Kidd; Gan, Chiao Chin; Chan, Chris Yin Wei

2016-02-01

A prospective, nonrandomized study. To evaluate the effectiveness of periodic intraoperative text messages (SMS) in reducing parental anxiety level during posterior spinal fusion (PSF) surgery for adolescent idiopathic scoliosis (AIS) patients. No studies have reported the use of intraoperative SMS to reduce level of anxiety in parents of patients who are undergoing AIS corrective surgery. Parents of 50 AIS patients were studied at two centers. Group 1 did not receive any SMS whereas those in Group 2 received periodic SMS. Parents' anxiety were assessed using a validated Visual Analog Scale for anxiety (VAS-A) and the anxiety component of the Hospital Anxiety Depression Score (HADS). The assessment was carried out at five different periods: (P1) 6 hours before the surgery; (P2) at separation in the operation theatre; (P3) 1 hour after commencement of surgery; (P4) immediately after completion of surgery; (P5) 1 day postsurgery. A total of 96 parents (47 fathers, 49 mothers) were involved in this study. Both groups were comparable in terms of demographics and education level. The mean VAS for Group 1 peaked at P2 and the HADS scores peaked at P3. The anxiety level of Group 1 remained high at P2, P3, and P4. There was a steady decline in parental anxiety in Group 2 from P1 to P5. There were significantly lower mean VAS score and HADS score for both father and mother in Group 2 during P3 and P4. The mean HADS scores for parents in Group 1 at P2 and P3 were higher than 8, which indicate abnormal anxiety. The anxiety levels of parents receiving the SMS were significantly lower than parents who did not receive any messages. Thus, intraoperative SMS is an effective intervention to decrease parental anxiety of AIS patients undergoing PSF surgery. 3.

Retinal Crystals in Type 2 Idiopathic Macular Telangiectasia

PubMed Central

Sallo, Ferenc B; Leung, Irene; Chung, Mina; Wolf-Schnurrbusch, Ute EK; Dubra, Alfredo; Williams, David R; Clemons, Traci; Pauleikhoff, Daniel; Bird, Alan C; Peto, Tunde

2012-01-01

Purpose To characterize the phenotype and investigate the associations of intraretinal crystalline deposits in a large cohort of Type 2 Idiopathic Macular Telangiectasia (MacTel) Design Case-control study Participants Patients with and without retinal crystals from the Macular Telangiectasia Project, an international multi-centre prospective study of Type 2 MacTel. Methods Grading of stereoscopic 30° colour fundus (CF), confocal blue light reflectance (CBR), red-free (RF) and infrared (IR) images was performed according to the MacTel Natural History Study protocol and staged using the classification system devised by Gass & Blodi. SD-OCT and adaptive optics imaging were used for a finer analysis of the phenotype. Associations between crystals and other characteristics of the disease as well as potential risk factors were investigated. Main outcome measures Presence of crystals, fundus signs of MacTel, clinical characteristics, presence of potential risk factors of MacTel. Results Out of 443 probands enrolled in the MacTel study, 203 (46%) had crystalline deposits present; 60% of the cases were bilateral at baseline. Eyes with crystals had a mean letter score of 70.7 (SD=15.9) while those without crystals had a mean of 66.5 letters (SD=15.5, p<0.001). Crystals were present at all stages of the disease and showed high reflectivity within a wide wavelength range. They were located at the anterior surface of the nerve fibre layer, arranged along the nerve fibres, within an annular area centred on the fovea. Significant associations of crystalline deposits were found with a loss of retinal transparency, MPOD loss, fluorescein leakage, retinal thickness and a break in the IS/OS junction line. Associations with environmental risk factors were not found. Conclusions Intraretinal crystals are a frequent phenomenon associated with type 2 MacTel, they may appear at all stages and may aid in the early diagnosis of the disease. Their morphology further implicates Müller cells

Vocal cord paralysis: What matters between idiopathic and non-idiopathic cases?

PubMed

Özbal Koç, Ayça Eltaf; Türkoğlu, Seda Babakurban; Erol, Ozan; Erbek, Selim

2016-01-01

This study aims to evaluate the demographic and clinical characteristics of patients with idiopathic and non-idiopathic vocal cord paralysis (VCP). This retrospective cohort was performed on data extracted from medical files of 92 consecutive patients (43 males, 49 females; median age 52.1±23.1 years; min. 1 - max. 87) with VCP diagnosed in the otorhinolaryngology department between April 2012 and December 2015. Diagnoses associated with VCP, side of involvement (right, left or bilateral) and previous medical histories were noted and compared between patients with idiopathic and non-idiopathic VCP. Vocal cord paralysis occurred on the left side (n=56, 60.9%), right side (n=28, 30.4%) or bilaterally (n=8, 8.7%). A clinical entity related with VCP was identified in 63 patients (68.5%), while 29 (31.5%) patients had idiopathic VCP. Most common etiologies for VCP were thyroid surgery (n=32, 34.8%), cardiovascular surgery (n=9, 9.8%), lung cancer (n=6, 6.5%) and cardiac anomalies (n=4, 4.3%), respectively. Patients with idiopathic VCP were significantly older (p<0.001), while gender distribution (p=0.121) and side of involvement (p=0.340) did not differ between two groups. Vocal cord paralysis is a relatively common clinical entity with substantial rate of morbidity. Identification of the underlying etiology and awareness on the clinical characteristics are keystones for foreseeing complications and determining the appropriate therapeutic modality.

Analysis of cervical kyphosis and spinal balance in young idiopathic scoliosis patients classified by the apex of thoracic kyphosis.

PubMed

Ito, Kenyu; Imagama, Shiro; Ito, Zenya; Ando, Kei; Kobayashi, Kazuyoshi; Hida, Tetsuro; Tsushima, Mikito; Ishikawa, Yoshimoto; Matsumoto, Akiyuki; Nishida, Yoshihiro; Ishiguro, Naoki

2016-10-01

Sagittal balance has recently been the focus of studies aimed at understanding the correction force required for both coronal and sagittal malalignment. However, the correlation between cervical kyphosis and sagittal balance in AIS patients has yet to be thoroughly investigated. This study aimed to clarify the correlation between cervical alignment and spinal balance in patients with adolescent idiopathic scoliosis (AIS). Here, we hypothesized that cervical kyphosis patients can be classified into groups by the apex of thoracic kyphosis. This study included 92 AIS patients (84 females, 8 males; mean age, 15.1 years). Patients were divided into the cervical lordosis (CL), cervical sigmoid (CS), or cervical kyphosis (CK) groups and further classified according to the apex of thoracic kyphosis into High (above T3), Middle (T4-T9), and Low (below T10) groups. There were 17 (18.5 %), 22 (23.9 %), and 53 (57.6 %) patients with CL, CS, and CK, respectively. In the CK group, 13 had CK-High, 35 had CK-Middle, and 5 had CK-Low. The C7 sagittal vertical axis (C7SVA) measurements were most backward in CK-High and most forward in CK-Low. The T5-12 kyphosis (TK) measurement was significantly lower in CK-High. Most AIS patients had kyphotic cervical alignment. Patients with CK can be classified as having CK-High, CK-Middle, or CK-Low according to the apex of thoracic kyphosis. CK-High is due to thoracic hypokyphosis with a backward balanced C7SVA. CK-Middle is well-balanced cervical kyphosis. CK-Low has forward-bent global kyphosis of the cervicothoracic spine that positioned the C7SVA forward.

DREAM regulates BDNF-dependent spinal sensitization

PubMed Central

2010-01-01

Background The transcriptional repressor DREAM (downstream regulatory element antagonist modulator) controls the expression of prodynorphin and has been involved in the modulation of endogenous responses to pain. To investigate the role of DREAM in central mechanisms of pain sensitization, we used a line of transgenic mice (L1) overexpressing a Ca2+- and cAMP-insensitive DREAM mutant in spinal cord and dorsal root ganglia. Results L1 DREAM transgenic mice showed reduced expression in the spinal cord of several genes related to pain, including prodynorphin and BDNF (brain-derived neurotrophic factor) and a state of basal hyperalgesia without change in A-type currents. Peripheral inflammation produced enhancement of spinal reflexes and increased expression of BDNF in wild type but not in DREAM transgenic mice. The enhancement of the spinal reflexes was reproduced in vitro by persistent electrical stimulation of C-fibers in wild type but not in transgenic mice. Exposure to exogenous BDNF produced a long-term enhancement of dorsal root-ventral root responses in transgenic mice. Conclusions Our results indicate that endogenous BDNF is involved in spinal sensitization following inflammation and that blockade of BDNF induction in DREAM transgenic mice underlies the failure to develop spinal sensitization. PMID:21167062

Periprosthetic Tissue Loss in Patients With Idiopathic Vitreous Inflammation After the Boston Keratoprosthesis.

PubMed

Grassi, Christina M; Cruzat, Andrea; Taniguchi, Elise V; Crnej, Alja; Colby, Kathryn A; Dohlman, Claes H; Chodosh, James

2015-11-01

Idiopathic vitritis is a poorly understood complication after Boston keratoprosthesis surgery with unclear etiology. We sought to determine whether an association exists between periprosthetic corneal tissue loss and the development of idiopathic vitritis in keratoprosthesis recipients. Thirteen Boston type I keratoprosthesis recipient eyes with a history of idiopathic vitritis and 34 type I keratoprosthesis recipient eyes with no history of idiopathic vitritis underwent anterior segment optical coherence tomography (AS-OCT) at a median time postoperatively of 2.4 years versus 1.9 years (range, 0.5-14.2 vs. 0.1-13.6 years), respectively. Areas of corneal graft tissue loss ("gaps") around the keratoprosthesis stem were identified and analyzed by 2 masked observers. The difference in the presence, number, and size of gaps was compared between cases and controls. A periprosthetic gap was identified more commonly in idiopathic vitritis cases than in controls on AS-OCT (11/13, 86% vs. 11/34, 33.3%, P < 0.001). The number of gaps between cases and controls was also significantly different (2.6 ± 1.6 vs. 0.5 ± 0.8, P < 0.001), but not the estimated gap area (0.056 ± 0.049 mm² vs. 0.039 ± 0.025 mm², P = 0.22). A significantly higher proportion of keratoprosthesis recipient eyes with idiopathic vitritis had corneal tissue loss around the keratoprosthesis stem than did controls. Tissue loss could serve as an entry point for debris or bacterial components, triggering idiopathic vitritis. Our study underscores the utility of AS-OCT imaging in the postoperative management of keratoprosthesis patients.

Surface Curvatures Computation from Equidistance Contours

NASA Astrophysics Data System (ADS)

Tanaka, Hiromi T.; Kling, Olivier; Lee, Daniel T. L.

1990-03-01

The subject of our research is on the 3D shape representation problem for a special class of range image, one where the natural mode of the acquired range data is in the form of equidistance contours, as exemplified by a moire interferometry range system. In this paper we present a novel surface curvature computation scheme that directly computes the surface curvatures (the principal curvatures, Gaussian curvature and mean curvature) from the equidistance contours without any explicit computations or implicit estimates of partial derivatives. We show how the special nature of the equidistance contours, specifically, the dense information of the surface curves in the 2D contour plane, turns into an advantage for the computation of the surface curvatures. The approach is based on using simple geometric construction to obtain the normal sections and the normal curvatures. This method is general and can be extended to any dense range image data. We show in details how this computation is formulated and give an analysis on the error bounds of the computation steps showing that the method is stable. Computation results on real equidistance range contours are also shown.

Aquatic Therapy for a Child with Type III Spinal Muscular Atrophy: A Case Report

ERIC Educational Resources Information Center

Salem, Yasser; Gropack, Stacy Jaffee

2010-01-01

Spinal muscular atrophy (SMA) is a neuromuscular disorder characterized by degeneration of alpha motor neurons. This case report describes an aquatic therapy program and the outcomes for a 3-year-old girl with type III SMA. Motor skills were examined using the 88-item Gross Motor Function Measure (GMFM), the Peabody Developmental Motor Scales…

Spinal neurofibromatosis in a family with classical neurofibromatosis type 1 and a novel NF1 gene mutation.

PubMed

Nicita, Francesco; Torrente, Isabella; Spalice, Alberto; Bottillo, Irene; Papetti, Laura; Pinna, Valentina; Ursitti, Fabiana; Ruggieri, Martino

2014-02-01

Familial spinal neurofibromatosis (FSNF) is a rare form of neurofibromatosis type 1 (NF1) characterized by multiple, histologically proven neurofibromas of the spinal roots leaving no intact segments and associated neurofibromas of major peripheral nerves. It is sometimes associated with other NF1 stigmata. Most patients have NF1 gene mutations. We describe a patient who fulfilled the diagnostic criteria for spinal neurofibromatosis and belonged to a family in which other affected members exhibited classical NF1 stigmata. A novel missense (c.7109 T>A; p.Val2370Asp) mutation in exon 39 of the NF1 gene was present in the affected family members. The family displayed extreme phenotypic variability in the spectrum of NF1. To our knowledge, this is the first patient with spinal neurofibromatosis in the context of classical NF1 with an NF1 gene mutation. The term FSNF is inaccurate as this condition simply reflects the typical autosomal dominant pattern of NF1 inheritance with phenotypoc variability and does not encompass patients with sporadic disease or those in the context of a classical NF1 phenotype as reported in the present family. The term could be replaced by "spinal neurofibromatosis". Copyright © 2013 Elsevier Ltd. All rights reserved.

Spinal hemianesthesia: Unilateral and posterior

PubMed Central

Imbelloni, Luiz Eduardo

2014-01-01

The injection of a non-isobaric local anesthetic should induce a unilateral spinal anesthesia in patients in a lateral decubitus position. The posterior spinal hemianesthesia only be obtained with hypobaric solutions injected in the jackknife position. The most important factors to be considered when performing a spinal hemianesthesia are: type and gauge of the needle, density of the local anesthetic relative to the CSF, position of the patient, speed of administration of the solution, time of stay in position, and dose/concentration/volume of the anesthetic solution. The distance between the spinal roots on the right-left sides and anterior-posterior is, approximately, 10-15 mm. This distance allows performing unilateral spinal anesthesia or posterior spinal anesthesia. The great advantage of obtaining spinal hemianesthesia is the reduction of cardiovascular changes. Likewise, both the dorsal and unilateral sensory block predominates in relation to the motor block. Because of the numerous advantages of producing spinal hemianesthesia, anesthesiologists should apply this technique more often. This review considers the factors which are relevant, plausible and proven to obtain spinal hemianesthesia. PMID:25886320

Total Mean Curvature, Scalar Curvature, and a Variational Analog of Brown-York Mass

NASA Astrophysics Data System (ADS)

Mantoulidis, Christos; Miao, Pengzi

2017-06-01

We study the supremum of the total mean curvature on the boundary of compact, mean-convex 3-manifolds with nonnegative scalar curvature, and a prescribed boundary metric. We establish an additivity property for this supremum and exhibit rigidity for maximizers assuming the supremum is attained. When the boundary consists of 2-spheres, we demonstrate that the finiteness of the supremum follows from the previous work of Shi-Tam and Wang-Yau on the quasi-local mass problem in general relativity. In turn, we define a variational analog of Brown-York quasi-local mass without assuming that the boundary 2-sphere has positive Gauss curvature.

Cosmological backreaction within the Szekeres model and emergence of spatial curvature

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

Bolejko, Krzysztof, E-mail: krzysztof.bolejko@sydney.edu.au

This paper discusses the phenomenon of backreaction within the Szekeres model. Cosmological backreaction describes how the mean global evolution of the Universe deviates from the Friedmannian evolution. The analysis is based on models of a single cosmological environment and the global ensemble of the Szekeres models (of the Swiss-Cheese-type and Styrofoam-type). The obtained results show that non-linear growth of cosmic structures is associated with the growth of the spatial curvature Ω{sub R} (in the FLRW limit Ω{sub R} → Ω {sub k} ). If averaged over global scales the result depends on the assumed global model of the Universe. Withinmore » the Swiss-Cheese model, which does have a fixed background, the volume average follows the evolution of the background, and the global spatial curvature averages out to zero (the background model is the ΛCDM model, which is spatially flat). In the Styrofoam-type model, which does not have a fixed background, the mean evolution deviates from the spatially flat ΛCDM model, and the mean spatial curvature evolves from Ω{sub R} =0 at the CMB to Ω{sub R} ∼ 0.1 at 0 z =. If the Styrofoam-type model correctly captures evolutionary features of the real Universe then one should expect that in our Universe, the spatial curvature should build up (local growth of cosmic structures) and its mean global average should deviate from zero (backreaction). As a result, this paper predicts that the low-redshift Universe should not be spatially flat (i.e. Ω {sub k} ≠ 0, even if in the early Universe Ω {sub k} = 0) and therefore when analysing low- z cosmological data one should keep Ω {sub k} as a free parameter and independent from the CMB constraints.« less

Cosmological backreaction within the Szekeres model and emergence of spatial curvature

NASA Astrophysics Data System (ADS)

Bolejko, Krzysztof

2017-06-01

This paper discusses the phenomenon of backreaction within the Szekeres model. Cosmological backreaction describes how the mean global evolution of the Universe deviates from the Friedmannian evolution. The analysis is based on models of a single cosmological environment and the global ensemble of the Szekeres models (of the Swiss-Cheese-type and Styrofoam-type). The obtained results show that non-linear growth of cosmic structures is associated with the growth of the spatial curvature ΩScript R (in the FLRW limit ΩScript R → Ωk). If averaged over global scales the result depends on the assumed global model of the Universe. Within the Swiss-Cheese model, which does have a fixed background, the volume average follows the evolution of the background, and the global spatial curvature averages out to zero (the background model is the ΛCDM model, which is spatially flat). In the Styrofoam-type model, which does not have a fixed background, the mean evolution deviates from the spatially flat ΛCDM model, and the mean spatial curvature evolves from ΩScript R =0 at the CMB to ΩScript R ~ 0.1 at 0z =. If the Styrofoam-type model correctly captures evolutionary features of the real Universe then one should expect that in our Universe, the spatial curvature should build up (local growth of cosmic structures) and its mean global average should deviate from zero (backreaction). As a result, this paper predicts that the low-redshift Universe should not be spatially flat (i.e. Ωk ≠ 0, even if in the early Universe Ωk = 0) and therefore when analysing low-z cosmological data one should keep Ωk as a free parameter and independent from the CMB constraints.

Spline-Based Smoothing of Airfoil Curvatures

NASA Technical Reports Server (NTRS)

Li, W.; Krist, S.

2008-01-01

Constrained fitting for airfoil curvature smoothing (CFACS) is a splinebased method of interpolating airfoil surface coordinates (and, concomitantly, airfoil thicknesses) between specified discrete design points so as to obtain smoothing of surface-curvature profiles in addition to basic smoothing of surfaces. CFACS was developed in recognition of the fact that the performance of a transonic airfoil is directly related to both the curvature profile and the smoothness of the airfoil surface. Older methods of interpolation of airfoil surfaces involve various compromises between smoothing of surfaces and exact fitting of surfaces to specified discrete design points. While some of the older methods take curvature profiles into account, they nevertheless sometimes yield unfavorable results, including curvature oscillations near end points and substantial deviations from desired leading-edge shapes. In CFACS as in most of the older methods, one seeks a compromise between smoothing and exact fitting. Unlike in the older methods, the airfoil surface is modified as little as possible from its original specified form and, instead, is smoothed in such a way that the curvature profile becomes a smooth fit of the curvature profile of the original airfoil specification. CFACS involves a combination of rigorous mathematical modeling and knowledge-based heuristics. Rigorous mathematical formulation provides assurance of removal of undesirable curvature oscillations with minimum modification of the airfoil geometry. Knowledge-based heuristics bridge the gap between theory and designers best practices. In CFACS, one of the measures of the deviation of an airfoil surface from smoothness is the sum of squares of the jumps in the third derivatives of a cubicspline interpolation of the airfoil data. This measure is incorporated into a formulation for minimizing an overall deviation- from-smoothness measure of the airfoil data within a specified fitting error tolerance. CFACS has been

Studies of the effects of curvature on dilution jet mixing

NASA Technical Reports Server (NTRS)

Holdeman, James D.; Srinivasan, Ram; Reynolds, Robert S.; White, Craig D.

1992-01-01

An analytical program was conducted using both three-dimensional numerical and empirical models to investigate the effects of transition liner curvature on the mixing of jets injected into a confined crossflow. The numerical code is of the TEACH type with hybrid numerics; it uses the power-law and SIMPLER algorithms, an orthogonal curvilinear coordinate system, and an algebraic Reynolds stress turbulence model. From the results of the numerical calculations, an existing empirical model for the temperature field downstream of single and multiple rows of jets injected into a straight rectangular duct was extended to model the effects of curvature. Temperature distributions, calculated with both the numerical and empirical models, are presented to show the effects of radius of curvature and inner and outer wall injection for single and opposed rows of cool dilution jets injected into a hot mainstream flow.

Total curvature and total torsion of knotted random polygons in confinement

NASA Astrophysics Data System (ADS)

Diao, Yuanan; Ernst, Claus; Rawdon, Eric J.; Ziegler, Uta

2018-04-01

Knots in nature are typically confined spatially. The confinement affects the possible configurations, which in turn affects the spectrum of possible knot types as well as the geometry of the configurations within each knot type. The goal of this paper is to determine how confinement, length, and knotting affect the total curvature and total torsion of random polygons. Previously published papers have investigated these effects in the unconstrained case. In particular, we analyze how the total curvature and total torsion are affected by (1) varying the length of polygons within a fixed confinement radius and (2) varying the confinement radius of polygons with a fixed length. We also compare the total curvature and total torsion of groups of knots with similar complexity (measured as crossing number). While some of our results fall in line with what has been observed in the studies of the unconfined random polygons, a few surprising results emerge from our study, showing some properties that are unique due to the effect of knotting in confinement.

Spinal lordosis optimizes the requirements for a stable erect posture.

PubMed

Wagner, Heiko; Liebetrau, Anne; Schinowski, David; Wulf, Thomas; de Lussanet, Marc H E

2012-04-16

Lordosis is the bending of the lumbar spine that gives the vertebral column of humans its characteristic ventrally convex curvature. Infants develop lordosis around the time when they acquire bipedal locomotion. Even macaques develop a lordosis when they are trained to walk bipedally. The aim of this study was to investigate why humans and some animals develop a lumbar lordosis while learning to walk bipedally. We developed a musculoskeletal model of the lumbar spine, that includes an asymmetric, dorsally shifted location of the spinal column in the body, realistic moment arms, and physiological cross-sectional areas (PCSA) of the muscles as well as realistic force-length and force-velocity relationships. The model was used to analyze the stability of an upright body posture. According to our results, lordosis reduces the local joint torques necessary for an equilibrium of the vertebral column during an erect posture. At the same time lordosis increases the demands on the global muscles to provide stability. We conclude that the development of a spinal lordosis is a compromise between the stability requirements of an erect posture and the necessity of torque equilibria at each spinal segment.

Spinal lordosis optimizes the requirements for a stable erect posture

PubMed Central

2012-01-01

Background Lordosis is the bending of the lumbar spine that gives the vertebral column of humans its characteristic ventrally convex curvature. Infants develop lordosis around the time when they acquire bipedal locomotion. Even macaques develop a lordosis when they are trained to walk bipedally. The aim of this study was to investigate why humans and some animals develop a lumbar lordosis while learning to walk bipedally. Results We developed a musculoskeletal model of the lumbar spine, that includes an asymmetric, dorsally shifted location of the spinal column in the body, realistic moment arms, and physiological cross-sectional areas (PCSA) of the muscles as well as realistic force-length and force-velocity relationships. The model was used to analyze the stability of an upright body posture. According to our results, lordosis reduces the local joint torques necessary for an equilibrium of the vertebral column during an erect posture. At the same time lordosis increases the demands on the global muscles to provide stability. Conclusions We conclude that the development of a spinal lordosis is a compromise between the stability requirements of an erect posture and the necessity of torque equilibria at each spinal segment. PMID:22507595

Clinical and imaging features of spinal cord type of neuro Behçet disease: A case report and systematic review.

PubMed

Liu, Hui-Miao; Dong, Ci; Zhang, Yong-Zhi; Tian, Ya-Yun; Chen, Hong-Xu; Zhang, Sai; Li, Na; Gu, Ping

2017-10-01

To investigate the clinical and MRI characteristics of spinal cord nerve Behçet's disease. One patient with spinal cord nerve Behçet's disease was admitted to our hospital at October 20, 2015. Spinal cord nerve Behçet's disease. Retrospective analysis was performed on such case as well as 16 cases of spinal cord nerve Behçet's disease reported in China or abroad. Seventeen cases of spinal cord type of neuro Behçet's disease include 13 men and 4 women, with an average age of onset of 34.8 years old. The mean time from Behçet's disease symptoms to spinal cord involvement were 10.8 years. The initial symptom in one case was spinal cord injury, and another 4 cases had a recurrence course. The most common performance of spinal cord injury was sensory disturbance (82.4%), following by weakness (76.5%), sphincter or sexual dysfunction (58.8%), and pain in back, backside of neck or lower chest (29.4%). The number of cells was slightly increased or the protein level was increased in cerebrospinal fluid test. And the water channel protein antibody and oligoclonal band of serum levels were all negative. The spinal cord injury involved more than 3 vertebral bodies in 10 cases, and involved more than half of spinal cord in sagittal plane in 8 cases. In acute stage, shock therapy with large dose of glucocorticoid was generally applied both in China and abroad. The clinical features of spinal cord nerve Behçet's disease were various, making it easily misdiagnosed. Longitudinal extensive transverse myelitis performs as a characteristic manifestation.

Heritability of Thoracic Spine Curvature and Genetic Correlations With Other Spine Traits: The Framingham Study

PubMed Central

Yau, Michelle S; Demissie, Serkalem; Zhou, Yanhua; Anderson, Dennis E; Lorbergs, Amanda L; Kiel, Douglas P; Allaire, Brett T; Yang, Laiji; Cupples, L Adrienne; Travison, Thomas G; Bouxsein, Mary L; Karasik, David; Samelson, Elizabeth J

2017-01-01

Hyperkyphosis is a common spinal disorder in older adults, characterized by excessive forward curvature of the thoracic spine and adverse health outcomes. The etiology of hyperkyphosis has not been firmly established, but may be related to changes that occur with aging in the vertebrae, discs, joints, and muscles, which function as a unit to support the spine. Determining the contribution of genetics to thoracic spine curvature and the degree of genetic sharing among co-occurring measures of spine health may provide insight into the etiology of hyperkyphosis. The purpose of our study was to estimate heritability of thoracic spine curvature using T4–T12 kyphosis (Cobb) angle and genetic correlations between thoracic spine curvature and vertebral fracture, intervertebral disc height narrowing, facet joint osteoarthritis (OA), lumbar spine volumetric bone mineral density (vBMD), and paraspinal muscle area and density, which were all assessed from computed tomography (CT) images. Participants included 2063 women and men in the second and third generation offspring of the original cohort of the Framingham Study. Heritability of kyphosis angle, adjusted for age, sex, and weight, was 54% (95% confidence interval [CI], 43% to 64%). We found moderate genetic correlations between kyphosis angle and paraspinal muscle area ( ρ^G, −0.46; 95% CI, −0.67 to −0.26), vertebral fracture ( ρ^G, 0.39; 95% CI, 0.18 to 0.61), vBMD ( ρ^G,−0.23; 95% CI, −0.41 to −0.04), and paraspinal muscle density ( ρ^G,−0.22; 95% CI, −0.48 to 0.03). Genetic correlations between kyphosis angle and disc height narrowing ( ρ^G, 0.17; 95% CI, −0.05 to 0.38) and facet joint OA ( ρ^G, 0.05; 95% CI, −0.15 to 0.24) were low. Thoracic spine curvature may be heritable and share genetic factors with other age-related spine traits including trunk muscle size, vertebral fracture, and bone mineral density. PMID:27455046

Impact of alterations in target vessel curvature on branch durability after endovascular repair of thoracoabdominal aortic aneurysms.

PubMed

Sylvan, Joshua; Brier, Corey; Wolski, Katherine; Yanof, Jeffrey; Goel, Vikash; Kuramochi, Yuki; Eagleton, Matthew J

2016-03-01

The aim of this study was to evaluate curvature and its effect on the durability of visceral and renal branches in patients undergoing endovascular repair of thoracoabdominal aortic aneurysms (TAAAs) with fenestrated/branched endovascular aneurysm repair (F/B-EVAR). Quantitative branch vessel curvature assessment on branches arising from reinforced fenestrations was performed for 168 patients undergoing F/B-EVAR for type II and type III TAAAs. Preoperative and postoperative centerline coordinates were obtained using iNtuition (TeraRecon, Foster City, Calif) and exported into MATLAB (The MathWorks, Inc, Natick, Mass) based on thin-slice computed tomography imaging. Spline interpolation was applied to the centerline coordinates and resampled at 100 equally spaced points, and curvature calculations (κ, mm(-1)) were applied. Global and maximal curvatures for each of the target vessels were measured and categorized by severity. Categories for curvature were 0 to 0.05 mm(-1) (low), 0.05 to 0.1 mm(-1) (medium), 0.1 to 0.15 mm(-1) (high), and >0.15 mm(-1) (extreme) for global curvature and 0 to 0.2 mm(-1), 0.2 to 0.4 mm(-1), 0.4 to 0.6 mm(-1), and >0.6 mm(-1), respectively, for maximum curvature. Curvature variances were assessed for an association with vessel patency and need for reintervention. There were 558 vessels that underwent analysis based on repairs involving 650 vessels, whereby 92 vessels were excluded as they were treated with an external helical branch (58 celiac arteries and 34 superior mesenteric arteries). There was a significant difference found before and after F/B-EVAR for the global celiac artery curvature (median difference, -0.01; P < .001), global left renal artery curvature (median, -0.01; P = .014), maximum left renal artery curvature (median, 0.05; P < .001), and maximum right renal artery curvature (median, 0.03; P = .009). Maximum artery curvature was found to have shifted distally in all vessels postoperatively; 37 adverse events (AEs) were

Intracellular magnetophoresis of amyloplasts and induction of root curvature

NASA Technical Reports Server (NTRS)

Kuznetsov, O. A.; Hasenstein, K. H.

1996-01-01

High-gradient magnetic fields (HGMFs) were used to induce intracellular magnetophoresis of amyloplasts. The HGMFs were generated by placing a small ferromagnetic wedge into a uniform magnetic field or at the gap edge between two permanent magnets. In the vicinity of the tip of the wedge the dynamic factor of the magnetic field, delta(H2/2), was about 10(9) Oe2.cm-1, which subjected the amyloplasts to a force comparable to that of gravity. When roots of 2-d-old seedlings of flax (Linum usitatissimum L.) were positioned vertically and exposed to an HGMF, curvature away from the wedge was transient and lasted approximately 1 h. Average curvature obtained after placing magnets, wedge and seedlings on a 1-rpm clinostat for 2 h was 33 +/- 5 degrees. Roots of horizontally placed control seedlings without rotation curved about 47 +/- 4 degrees. The time course of curvature and changes in growth rate were similar for gravicurvature and for root curvature induced by HGMFs. Microscopy showed displacement of amyloplasts in vitro and in vivo. Studies with Arabidopsis thaliana (L.) Heynh. showed that the wild type responded to HGMFs but the starchless mutant TC7 did not. The data indicate that a magnetic force can be used to study the gravisensing and response system of roots.

Efficacy of corrective spinal orthoses on gait and energy consumption in scoliosis subjects: a literature review.

PubMed

Daryabor, Alieh; Arazpour, Mokhtar; Samadian, Mohammad; Veiskarami, Masoumeh; Ahmadi Bani, Monireh

2017-05-01

Adolescent idiopathic scoliosis (AIS) is a progressive growth disease that affects spinal anatomy, mobility, and left-right trunk symmetry. As a consequence, AIS can modify human gait. Spinal orthoses are a commonly used conservative method for the treatment of AIS. This review evaluated the AIS spinal orthosis literature that involved gait and energy consumption evaluations. Literature review. According to the population intervention comparison outcome measure methods and based on selected keywords, 10 studies met the inclusion criteria. People with AIS who wore a spinal orthosis, compared with able-bodied participants, walked slower with decreased hip and pelvic movements, decreased hip mediolateral forces, ground reaction force asymmetry, and excessive energy cost. Pelvis and hip frontal plane motion decreased when wearing an orthosis. Hip and pelvis movement symmetry improved when using an orthosis. Ankle and foot kinematics did not change with orthotic intervention. People with AIS continued to have excessive energy expenditure with an orthosis. Spinal orthoses may be considered for improving the walking style, although energy cost does not decline following the orthotic intervention. Implications for Rehabilitations Problems related to scoliosis include reduced quality of life, disability, pain, postural alterations, sensory perturbations, standing instability and gait modifications. Wearing corrective spinal orthoses in AIS subjects produce a reduction in walking speed and cadence, increase in stride length and reduction of gait load asymmetry compared to without brace condition. Spinal orthoses do not decline excessive energy expenditure to walk versus without it.

Geometrical modified nesbit corporoplasty to correct different types of penile curvature: description of the surgical procedure based on geometrical principles and long-term results.

PubMed

Vicini, P; Di Nicola, S; Antonini, G; De Berardinis, E; Gentile, V; De Marco, F

2016-11-01

We present the use of a modified corporoplasty, based on geometrical principles, to determine the exact site for the incision in the tunica or plaque and the exact amount of albuginea for overlaying to correct with extreme precision the different types of congenital or acquired penile curvature due to Peyronie's disease. To describe our experience with a new surgical procedure for the enhancement of penile curvature avoiding any overcorrection or undercorrection. Between March 2004 and April 2013, a total of 74 patients underwent the geometrical modified corporoplasty. All patients had congenital curvature until 90° or acquired stable penile curvature 'less' than 60°, that made sexual intercourse very difficult or impossible, normal erectile function, absence of hourglass or hinge effect. Preoperative testing included a physical examination, 3 photographs (frontal, dorsal and lateral) of penis during erection, a 10 mcg PGE1-induced erection and Doppler ultrasound, administration of the International Index of Erectile Function (IIEF-15) questionnaire. A follow-up with postoperative evaluation at 12 weeks, 12 and 24 months, included the same preoperative testing. Satisfaction rates were better assessed with the use of validated questionnaire such as the International Erectile Dysfunction Inventory of the Treatment Satisfaction (EDITS). Statistical analysis with Student's t-test was performed using commercially available, personal computer software. A total of 25 patients had congenital penile curvature with a mean deviation of 46.8° (range 40-90), another 49 patients had Peyronie's disease with a mean deviation of 58.4 (range 45-60). No major complications were reported. Postoperative correction of the curvature was achieved in all patients (100%). Neither undercorrection nor overcorrection were recorded. No significant relapse (curvature>15°) occurred in our patients. Shortening of the penis was reported by 74% but did not influence the high overall

Influence of the surface curvature of carbon nanotubes on their conductivity in the dirac approximation

NASA Astrophysics Data System (ADS)

Kolesnikov, D. V.; Ivanchenko, G. S.; Lebedev, N. G.

2016-06-01

A method of surface curvature of carbon nanotubes has been proposed for quantitative estimation of the longitudinal conductivity of nanotubes. A dispersion relation for the electron spectrum of single-walled carbon nanotubes has been obtained analytically. The change in the zone structure of nanotubes of various types and diameters caused by taking into account the surface curvature has been analyzed. The temperature dependence of the longitudinal component of conductivity with allowance for the surface curvature for a series of nanotubes has been calculated. The comparison with the conductivity of a plane graphene has been performed. It has been shown that, in zig-zag tubes, the correction of the conductivity for the surface curvature decreases with an increase in temperature as well as with an increase in the radius of curvature.

Compound curvature laser window development

NASA Technical Reports Server (NTRS)

Verhoff, Vincent G.

1993-01-01

The NASA Lewis Research Center has developed and implemented a unique process for forming flawless compound curvature laser windows. These windows represent a major part of specialized, nonintrusive laser data acquisition systems used in a variety of compressor and turbine research test facilities. This report summarizes the main aspects of compound curvature laser window development. It is an overview of the methodology and the peculiarities associated with the formulation of these windows. Included in this discussion is new information regarding procedures for compound curvature laser window development.

Chitin Oligosaccharide (COS) Reduces Antibiotics Dose and Prevents Antibiotics-Caused Side Effects in Adolescent Idiopathic Scoliosis (AIS) Patients with Spinal Fusion Surgery.

PubMed

Qu, Yang; Xu, Jinyu; Zhou, Haohan; Dong, Rongpeng; Kang, Mingyang; Zhao, Jianwu

2017-03-14

Antibiotics are always considered for surgical site infection (SSI) in adolescent idiopathic scoliosis (AIS) surgery. However, the use of antibiotics often causes the antibiotic resistance of pathogens and side effects. Thus, it is necessary to explore natural products as drug candidates. Chitin Oligosaccharide (COS) has anti-inflammation and anti-bacteria functions. The effects of COS on surgical infection in AIS surgery were investigated. A total of 312 AIS patients were evenly and randomly assigned into control group (CG, each patient took one-gram alternative Azithromycin/Erythromycin/Cloxacillin/Aztreonam/Ceftazidime or combined daily), experiment group (EG, each patient took 20 mg COS and half-dose antibiotics daily), and placebo group (PG, each patient took 20 mg placebo and half-dose antibiotics daily). The average follow-up was one month, and infection severity and side effects were analyzed. The effects of COS on isolated pathogens were analyzed. SSI rates were 2%, 3% and 8% for spine wounds and 1%, 2% and 7% for iliac wound in CG, EG and PG ( p < 0.05), respectively. COS reduces the side effects caused by antibiotics ( p < 0.05). COS improved biochemical indexes and reduced the levels of interleukin (IL)-6 and tumor necrosis factor (TNF) alpha. COS reduced the antibiotics dose and antibiotics-caused side effects in AIS patients with spinal fusion surgery by improving antioxidant and anti-inflammatory activities. COS should be developed as potential adjuvant for antibiotics therapies.

Curvature Analysis of Cardiac Excitation Wavefronts

DTIC Science & Technology

2013-04-01

required at this level either. To enable this kind of analysis, a type field is added to the polyline data structure, too. The downside of reusing the...GPU-based parallel methods. The wave curvature and the refractory period of the cardiac cells influence the motion of cardiac waves. The role of...propagation speed, the action potential duration, and the refractory period is studied. In the recent work of [26], multiple spirals and their

Current-controlled curvature of coated micromirrors

NASA Astrophysics Data System (ADS)

Liu, Wei; Talghader, Joseph J.

2003-06-01

Precise control of micromirror curvature is critical in many optical microsystems. Micromirrors with current-controlled curvature are demonstrated. The working principle is that resistive heating changes the temperature of the micromirrors and thermal expansion induces a controlled curvature whose magnitude is determined by coating design. For example, for wide focal-length tuning, the radius of curvature of a gold-coated mirror was tuned from 2.5 to 8.2 mm over a current-induced temperature range from 22° to 72 °C. For fine focal-length tuning, the radius of curvature of a dielectric-coated (SiO2/Y2O3 λ/4 pairs) mirror was tuned from -0.68 to -0.64 mm over a current-induced temperature range from 22 to 84 °C. These results should be readily extendable to mirror flattening or real-time adaptive shape control.

Patients' experience of adolescent idiopathic scoliosis surgery: a phenomenological analysis.

PubMed

Honeyman, Cheryl; Davison, Jean

2016-09-12

Background Adolescent idiopathic scoliosis is a three-dimensional curvature of the spine of unknown cause that occurs in often otherwise fit young people. A complex surgical procedure is required for the most severe curves. Quantitative literature suggests scoliosis surgery improves patients' lives, while qualitative literature focuses on patients' concerns rather than their experience. Aims To explore how adolescents interpret their perioperative experience. Method Six participants, aged 15-18, were interviewed and transcripts were analysed. Findings Four themes were identified: shock, fears and worries; parental interaction; coping; and motivation and positivity. Conclusion Participants were reluctant to share concerns, however those they shared related more to fear of the unknown and lack of control than specific issues such as pain. Participants depended on their parents, especially their mothers, during the perioperative period, and they recognised their parents' stress. Participants coped well, were motivated and had a positive outlook.

Clinical features, course and prognosis of idiopathic membranous nephropathy depending on the presence of antibodies against M-type phospholipase A2 receptor.

PubMed

Jatem Escalante, Elías; Segarra Medrano, Alfons; Carnicer Cáceres, Clara; Martín-Gómez, M Adoración; Salcedo Allende, María Teresa; Ostos Roldan, Helena; Agraz Pamplona, Irene

2015-01-01

In membranous nephropathy, the presence of antibodies against M-type phospholipase A2 receptor is considered highly specific for idiopathic forms. However, no specific association to a particular clinical profile has been found for such antibodies. To assess potential differences in initial clinical profile, course and prognosis of idiopathic membranous nephropathy depending on the presence of anti-PLA2R antibodies. Eighty-five patients with idiopathic membranous nephropathy were included (55 anti-PLA2R-positive and 30 anti-PLA2R-negative). Clinical, biochemical and pathological variables were recorded at the time of diagnosis. Frequency of spontaneous remission, incidence of response to first-line therapy, frequency and number of recurrences, survival of renal function free from renal replacement therapy, survival of renal function free from chronic renal insufficiency and frequency of occurrence of malignant, infectious or autoimmune diseases during follow-up were recorded. At the time of diagnosis, anti-PLA2R-negative patients were significantly older and had a higher frequency of spontaneous remission. No differences were noted in the response to first-line treatment, frequency and number of recurrences, survival of renal function free from renal replacement therapy, or survival of renal function free from chronic renal insufficiency. Anti-PLA2R-negative patients with idiopathic membranous nephropathy were older and experienced spontaneous remission more often than anti-PLA2R-positive patients. No differences in terms of treatment response, recurrences, and final prognosis were observed between both groups of patients. Copyright © 2015 The Authors. Published by Elsevier España, S.L.U. All rights reserved.

Critical review on non-operative management of adolescent idiopathic scoliosis.

PubMed

Wong, M S; Liu, W C

2003-12-01

There are a number of different non-operative interventions which aim to control moderate adolescent idiopathic scoliosis (AIS) from progression. Clinicians may find difficulties in the selection of appropriate interventions for AIS. A comprehensive literature review was carried out to study all contemporary non-operative interventions, it was noted that rigid spinal orthoses apparently give more curve control; however, it would compromise the patient's quality of life via those inevitable factors--physical constraint, poor acceptance and psychological disturbance. There is a trend to develop more effective, acceptable and user-friendly interventions. Under such an aspiration, the theories and clinical evidence of different interventions should be developed along the clinical pathway of early intervention with reliable indicators/predictors, patient's active participation, dynamic control mechanism, holistic psychological and psychosocial considerations, and effective and long-lasting outcome.

Sigma models with negative curvature

DOE PAGES

Alonso, Rodrigo; Jenkins, Elizabeth E.; Manohar, Aneesh V.

2016-03-16

Here, we construct Higgs Effective Field Theory (HEFT) based on the scalar manifold Hn, which is a hyperbolic space of constant negative curvature. The Lagrangian has a non-compact O(n, 1) global symmetry group, but it gives a unitary theory as long as only a compact subgroup of the global symmetry is gauged. Whether the HEFT manifold has positive or negative curvature can be tested by measuring the S-parameter, and the cross sections for longitudinal gauge boson and Higgs boson scattering, since the curvature (including its sign) determines deviations from Standard Model values.

Efficacy of tranexamic acid in reducing allogeneic blood products in adolescent idiopathic scoliosis surgery.

PubMed

Sui, Wen-yuan; Ye, Fang; Yang, Jun-lin

2016-04-27

Adolescent idiopathic scoliosis (AIS) surgery usually require prolonged operative times with extensive soft tissue dissection and significant perioperative blood loss, and allogeneic blood products are frequently needed. Methods to reduce the requirement for transfusion would have a beneficial effect on these patients. Although many previous studies have revealed the efficacy of tranexamic acid (TXA) in spinal surgery, there is still a lack of agreement concerning the reduction of both blood loss and transfusion requirements of large dose tranexamic acid (TXA) in surgery for adolescent idiopathic scoliosis (AIS). The objective of this study was to elevate the efficacy and safety of a large dose tranexamic acid (TXA) in reducing transfusion requirements of allogeneic blood products in adolescent idiopathic scoliosis (AIS) surgery using a retrospective study designed with historical control group. One hundred thirty seven consecutive AIS patients who underwent surgery treatment with posterior spinal pedicle systems from August 2011 to March 2015 in our scoliosis center were retrospectively reviewed. Patients were divided into two groups, the TXA group and the historical recruited no TXA group (NTXA). Preoperative demographics, radiographic parameters, operative parameters, estimated blood loss (EBL), total irrigation fluid, number of patients requiring blood transfusion, mean drop of Hb (Pre-op Hb-Post-op Hb), haematocrit pre and post-surgery, mean volume of blood transfusion, hospitalization time, and adverse effect were recorded and compared. All the patients were successfully treated with satisfied clinical and radiographic outcomes. There were 71 patients in the TXA group and 66 patients in the NTXA group. The preoperative demographics were homogeneity between two groups (P > 0.05). There were no significant difference in average operative time between two groups (209 min vs 215 min, p >0.05). Number of patients in the TXA group showed a significant decrease in

Driving Safety after Spinal Surgery: A Systematic Review

PubMed Central

Alkhalili, Kenan; Hannallah, Jack; Ibeche, Bashar; Bajammal, Sohail; Baco, Abdul Moeen

2017-01-01

This study aimed to assess driving reaction times (DRTs) after spinal surgery to establish a timeframe for safe resumption of driving by the patient postoperatively. The MEDLINE and Google Scholar databases were analyzed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) Statement for clinical studies that investigated changes in DRTs following cervical and lumbar spinal surgery. Changes in DRTs and patients' clinical presentation, pathology, anatomical level affected, number of spinal levels involved, type of intervention, pain level, and driving skills were assessed. The literature search identified 12 studies that investigated postoperative DRTs. Six studies met the inclusion criteria; five studies assessed changes in DRT after lumbar spine surgery and two studies after cervical spina surgery. The spinal procedures were selective nerve root block, anterior cervical discectomy and fusion, and lumbar fusion and/ordecompression. DRTs exhibited variable responses to spinal surgery and depended on the patients' clinical presentation, spinal level involved, and type of procedure performed. The evidence regarding the patients' ability to resume safe driving after spinal surgery is scarce. Normalization of DRT or a return of DRT to pre-spinal intervention level is a widely accepted indicator for safe driving, with variable levels of statistical significance owing to multiple confounding factors. Considerations of the type of spinal intervention, pain level, opioid consumption, and cognitive function should be factored in the assessment of a patient's ability to safely resume driving. PMID:28443178

Driving Safety after Spinal Surgery: A Systematic Review.

PubMed

Alhammoud, Abduljabbar; Alkhalili, Kenan; Hannallah, Jack; Ibeche, Bashar; Bajammal, Sohail; Baco, Abdul Moeen

2017-04-01

This study aimed to assess driving reaction times (DRTs) after spinal surgery to establish a timeframe for safe resumption of driving by the patient postoperatively. The MEDLINE and Google Scholar databases were analyzed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) Statement for clinical studies that investigated changes in DRTs following cervical and lumbar spinal surgery. Changes in DRTs and patients' clinical presentation, pathology, anatomical level affected, number of spinal levels involved, type of intervention, pain level, and driving skills were assessed. The literature search identified 12 studies that investigated postoperative DRTs. Six studies met the inclusion criteria; five studies assessed changes in DRT after lumbar spine surgery and two studies after cervical spina surgery. The spinal procedures were selective nerve root block, anterior cervical discectomy and fusion, and lumbar fusion and/ordecompression. DRTs exhibited variable responses to spinal surgery and depended on the patients' clinical presentation, spinal level involved, and type of procedure performed. The evidence regarding the patients' ability to resume safe driving after spinal surgery is scarce. Normalization of DRT or a return of DRT to pre-spinal intervention level is a widely accepted indicator for safe driving, with variable levels of statistical significance owing to multiple confounding factors. Considerations of the type of spinal intervention, pain level, opioid consumption, and cognitive function should be factored in the assessment of a patient's ability to safely resume driving.

Spinal cord compression in pseudohypoparathyroidism.

PubMed

Roberts, Timothy T; Khasnavis, Siddharth; Papaliodis, Dean N; Citone, Isabella; Carl, Allen L

2013-12-01

Spinal cord compression associated with pseudohypoparathyroidism (PHP) is an increasingly reported sequelae of the underlying metabolic syndrome. The association of neurologic dysfunction with PHP is not well appreciated. We believe this to be secondary to a combination of underlying congenital stenosis, manifest by short pedicles secondary to premature physeal closure, and hypertrophic ossification of the vertebral bony and ligamentous complexes. The purpose of this case report is to review the case of spinal stenosis in a child with PHP Type Ia. We are aware of only eight published reports of patients with PHP Type Ia and spinal stenosis-there are only two previously known cases of pediatric spinal stenosis secondary to PHP. This is a case report detailing the symptoms, diagnosis, interventions, complications, and ultimate outcomes of a pediatric patient undergoing spinal decompression and fusion for symptomatic stenosis secondary to PHP Type Ia. Literature search was reviewed regarding the reports of spinal stenosis and PHP, and the results are culminated and discussed. We report on a 14-year-old obese male with PHP and progressive lower extremity weakness secondary to congenital spinal stenosis. Examination revealed functional upper extremities with spastic paraplegia of bilateral lower extremities. The patient's neurologic function was cautiously monitored, but he deteriorated to a bed-bound state, preoperatively. The patient's chart was reviewed, summarized, and presented. Literature was searched using cross-reference of PHP and the terms "spinal stenosis," "myelopathy", "myelopathic," and "spinal cord compression." All relevant case reports were reviewed, and the results are discussed herein. The patient underwent decompression and instrumented fusion of T2-T11. He improved significantly with regard to lower extremity function, achieving unassisted ambulation function after extensive rehabilitation. Results from surgical decompression in previously reported

Palliative care in children with spinal muscular atrophy type I: What do they need?

PubMed

García-Salido, Alberto; de Paso-Mora, María García; Monleón-Luque, Manuel; Martino-Alba, Ricardo

2015-04-01

Our aim was to describe the clinical evolution and needs of children with spinal muscular atrophy type I treated in a domiciliary palliative care program. We undertook a retrospective chart review of nine consecutive patients. Descriptions of the clinical and demographic profile of children with spinal muscular atrophy (SMA) type I were referred to a pediatric palliative care team (PPCT). Six males and three females were admitted to the PPCT, all before six months of age, except for one afflicted with SMA type I with respiratory distress. The median time of attention was 57 days (range 1-150). The domiciliary attention mainly consisted of respiratory care. The patient with SMA type I with respiratory distress required domiciliary mechanical ventilation by tracheotomy. In all cases, a nasogastric tube (NT) was indicated. As end-of-life care, eight required morphine to manage the dyspnea, four received it only by enteral (oral or NT) administration, and four received it first by enteral administration with continuous subcutaneous infusion (CSI) later. Three of the four patients with CSI also received benzodiazepines. While they were attended by the PPCT, none required hospital admission. All the patients died at home except for the one attended to for just one day. Domiciliary care for these patients is possible. The respiratory morbidity and its management are the main issues. Application of an NT is useful to maintain nutritional balance. Morphine administration is necessary to manage the dyspnea. Palliative sedation is not always necessary.

Probing interaction and spatial curvature in the holographic dark energy model

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

Li, Miao; Li, Xiao-Dong; Wang, Shuang

2009-12-01

In this paper we place observational constraints on the interaction and spatial curvature in the holographic dark energy model. We consider three kinds of phenomenological interactions between holographic dark energy and matter, i.e., the interaction term Q is proportional to the energy densities of dark energy (ρ{sub Λ}), matter (ρ{sub m}), and matter plus dark energy (ρ{sub m}+ρ{sub Λ}). For probing the interaction and spatial curvature in the holographic dark energy model, we use the latest observational data including the type Ia supernovae (SNIa) Constitution data, the shift parameter of the cosmic microwave background (CMB) given by the five-year Wilkinsonmore » Microwave Anisotropy Probe (WMAP5) observations, and the baryon acoustic oscillation (BAO) measurement from the Sloan Digital Sky Survey (SDSS). Our results show that the interaction and spatial curvature in the holographic dark energy model are both rather small. Besides, it is interesting to find that there exists significant degeneracy between the phenomenological interaction and the spatial curvature in the holographic dark energy model.« less

Methodological quality of randomized controlled trials of spinal manipulation and mobilization in tension-type headache, migraine, and cervicogenic headache.

PubMed

Fernández-de-las-Peñas, César; Alonso-Blanco, Cristina; San-Roman, Jesús; Miangolarra-Page, Juan C

2006-03-01

Literature review of quality of clinical trials. To determine the methodological quality of published randomized controlled trials that used spinal manipulation and/or mobilization to treat patients with tension-type headache (TTH), cervicogenic headache (CeH), and migraine (M) in the last decade. TTH, CeH, and M are the most prevalent types of headaches seen in adults. Individuals who have headaches frequently use physical therapy, manual therapy, or chiropractic care. Randomized controlled trials are considered an optimal method with which to assess the efficacy of any intervention. Computerized literature searches were performed in MEDLINE, EMBASE, COCHRANE, AMED, MANTIS, CINHAL, and PEDro databases. Randomized controlled trials in which spinal manipulation and/or mobilization had been used for TTH, CeH, and M published in a peer-reviewed journal as full text, and with at least 1 clinically relevant outcome measure (ie, headache intensity, duration, or frequency) were reviewed. The methodological quality of the studies was assessed independently by 2 reviewers using a set of predefined criteria. Only 8 studies met all the inclusion criteria. One clinical trial evaluated spinal manipulation and mobilization together, and the remaining 7 assessed spinal manipulative therapy. No controlled trials analyzing exclusively the effects of spinal mobilization were found. Methodological scores ranged from 35 to 56 points out of a theoretical maximum of 100 points, indicating an overall poor methodology of the studies. Only 2 studies obtained a high-quality score (greater than 50 points). No significant differences in quality scores were found based on the type of headache investigated. Methodological quality was not associated with the year of publication (before 2000, or later) nor with the results (positive, neutral, negative) reported in the studies. The most common flaws were a small sample size, the absence of a placebo control group, lack of blinded patients, and no

Distal root curvatures in mandibular molars: analysis using digital panoramic X-rays.

PubMed

Fuentes, R; Farfán, C; Astete, N; Navarro, P; Arias, A

2018-01-01

The aim of this study was to describe the degree of curvature in distal roots in the first and second permanent mandibular molars in a Chilean patient sample. A cross-sectional descriptive study was conducted in which digital panoramic X-rays were analysed. Examinations of patients under 18 years, with signs of distortion or alteration in the contrast or the presence of pathologies that affected visualisation of the roots and pulp-chamber floor of the teeth to be analysed were excluded. Using the AutoCad software, an angle was drawn to represent the curve of the root in its different thirds, drawing lines inside the root canal from the pulp-chamber floor to the dental apex. Using the classic definition of dilaceration (root curvature > 90°), its prevalence was established. 412 teeth and roots were analysed, finding a dilaceration prevalence of 0.73% (n = 3). 84.72% of the roots presented some type of curvature. The middle third had the highest percentage of curvatures and the greatest average of angular curvature, whereas the cervical third was the straightest. No significant differences were found between the degree of curvature and the gender of the subjects, except for the apical third of tooth 3.6. The analysis of curvature by root third offers to the clinician a better perspective of the directional change of the roots and does not limit it to just the presence of curves in the apical third. The report of the angular degree of the curvatures, in addition to the prevalence of dilacerations, informs to the clinicians about the likelihood of finding difficulties when treating root canals. (Folia Morphol 2018; 77, 1: 131-137).

Mirror with thermally controlled radius of curvature

DOEpatents

Neil, George R.; Shinn, Michelle D.

2010-06-22

A radius of curvature controlled mirror for controlling precisely the focal point of a laser beam or other light beam. The radius of curvature controlled mirror provides nearly spherical distortion of the mirror in response to differential expansion between the front and rear surfaces of the mirror. The radius of curvature controlled mirror compensates for changes in other optical components due to heating or other physical changes. The radius of curvature controlled mirror includes an arrangement for adjusting the temperature of the front surface and separately adjusting the temperature of the rear surface to control the radius of curvature. The temperature adjustment arrangements can include cooling channels within the mirror body or convection of a gas upon the surface of the mirror. A control system controls the differential expansion between the front and rear surfaces to achieve the desired radius of curvature.

Idiopathic Inflammatory Myopathies

PubMed Central

Dimachkie, Mazen M.; Barohn, Richard J.

2012-01-01

The idiopathic inflammatory myopathies are a group of rare disorders including polymyositis (PM), dermatomyositis (DM), and autoimmune necrotizing myopathies (NMs). The idiopathic inflammatory myopathies share many similarities. They present acutely, subacutely, or chronically with marked proximal and symmetric muscle weakness, except for associated distal and asymmetric weakness in inclusion body myositis. The idiopathic inflammatory myopathies also share a variable degree of creatine kinase (CK) elevation and a nonspecifically abnormal electromyogram demonstrating an irritative myopathy. The muscle pathology demonstrates inflammatory exudates of variable distribution within the muscle fascicle. Despite these similarities, the idiopathic inflammatory myopathies are a heterogeneous group. The overlap syndrome (OS) refers to the association of PM, DM, or NM with connective tissue disease, such as scleroderma or systemic lupus erythematosus. In addition to elevated antinuclear antibodies (ANA), patients with OS may be weaker in the proximal arms than the legs mimicking the pattern seen in some muscular dystrophies. In this review, we focus on DM, PM, and NM and examine current and promising therapies. PMID:23117947

Management of subaxial cervical facet dislocation through anterior approach monitored by spinal cord evoked potential.

PubMed

Du, Wei; Wang, Cheng; Tan, Jiangwei; Shen, Binghua; Ni, Shuqin; Zheng, Yanping

2014-01-01

Retrospective case series. To discuss the clinical efficacy of anterior cervical surgery of decompression, reduction, stabilization, and fusion in treating subaxial cervical facet dislocation without spinal cord injury or with mild spinal cord injury monitored by spinal cord evoked potential. The optimal treatment of lower cervical facet dislocation has been controversial. Because of the risk of iatrogenic damage of neurological function, it is challenging for surgeons to manage the lower cervical facet dislocation without or with mild spinal cord injury. To avoid the risks, more secure strategy need to be designed. A retrospective study was performed on 17 cases of subaxial cervical facet dislocation without spinal cord injury or with mild spinal cord injury treated by anterior cervical surgery under spinal cord evoked potential monitor from January 2008 to June 2012. There were 12 males, 5 females, with a mean age of 40.1 years (from 21 to 73 yr). Dislocation sites: 1 in C3-C4, 2 in C4-C5, 6 in C5-C6, 8 in C6-C7; 10 cases with unilateral cervical facet dislocation, 7 cases with bilateral dislocation. Thirteen patients were preoperatively classified as grade D and 4 as E according to Frankel standard. All patients were followed up for average of 16 months. All operations were completed successfully. Postoperative radiographs showed that the sequence and curvature of the cervical spine were well recovered. And, evidence of intervertebral fusion was observed at 3 months in all cases. No redislocation or symptoms of spinal cord injury occurred. Thirteen cases with mild spinal cord injury recovered at 1 month after operation. Anterior cervical surgery of decompression, reduction, stabilization, and fusion monitored by spinal cord evoked potential is an effective and safe method for treatment of subaxial cervical facet dislocation without or with mild spinal cord injury. 4.

Instability in bacterial populations and the curvature tensor

NASA Astrophysics Data System (ADS)

Melgarejo, Augusto; Langoni, Laura; Ruscitti, Claudia

2016-09-01

In the geometry associated with equilibrium thermodynamics the scalar curvature Rs is a measure of the volume of correlation, and therefore the singularities of Rs indicates the system instabilities. We explore the use of a similar approach to study instabilities in non-equilibrium systems and we choose as a test example, a colony of bacteria. In this regard we follow the proposal made by Obata et al. of using the curvature tensor for studying system instabilities. Bacterial colonies are often found in nature in concentrated biofilms, or other colony types, which can grow into spectacular patterns visible under the microscope. For instance, it is known that a decrease of bacterial motility with density can promote separation into bulk phases of two coexisting densities; this is opposed to the logistic law for birth and death that allows only a single uniform density to be stable. Although this homogeneous configuration is stable in the absence of bacterial interactions, without logistic growth, a density-dependent swim speed v(ρ) leads to phase separation via a spinodal instability. Thus we relate the singularities in the curvature tensor R to the spinodal instability, that is the appearance of regions of different densities of bacteria.

Streamline-curvature effect in three-dimensional boundary layers

NASA Technical Reports Server (NTRS)

Reed, Helen L.; Lin, Ray-Sing; Petraglia, Media M.

1992-01-01

The effect of including wall and streamline curvature terms in swept-wing boundary-layer stability calculations is studied. The linear disturbance equations are cast on a fixed, body-intrinsic, curvilinear coordinate system. Those nonparallel terms which contribute mainly to the streamline-curvature effect are retained in this formulation and approximated by their local finite-difference values. Convex-wall curvature has a stabilizing effect, while streamline curvature is destabilizing if the curvature exceeds a critical value.

Curvature in solid oxide fuel cells

NASA Astrophysics Data System (ADS)

Li, Wenxia; Hasinska, Kathy; Seabaugh, Matt; Swartz, Scott; Lannutti, John

At this point in history, curvature is inherent to the laminated components that comprise solid oxide fuel cells (SOFCs). Surprisingly, however, this fact has never been previously quantified in the literature. In addition, potential curvature changes associated with NiO reduction and re-oxidation during operation have not been investigated. In this report, an optical profilometer was employed to non-destructively quantify the surface curvature or cracking behavior observed on a large scale in industrially manufactured cells. This provides insights into the challenges that the component materials face as well as additional appreciation for why, in spite of a concerted effort to commercialize SOFC power generation, all currently manufactured SOFC stacks fail. Our results demonstrate that cracked electrolyte areas (caused by differential sintering) are flatter than uncracked regions. The height of the electrolyte surface ranged from 86 to 289 μm above the baseline following sintering. Reduction typically results in increases in curvature of up to 214 μm. Initial crack density appears to affect curvature evolution during reduction; the higher the crack density, the smaller the curvature increase following reduction at 600 °C. In general, however, we observed that the electrolyte layer is remarkably resistant to further cracking during these typographic changes. Following oxidation at 750 °C, large changes in curvature (up to 280 μm) are noted that appear to be related to the strength of the bond between the electrolyte and the underlying anode.

Spinal Injury Rehabilitation in Singapore.

ERIC Educational Resources Information Center

Yen, H. L.; Chua, K.; Chan, W.

1998-01-01

This study reviewed 231 cases of spinal cord injury treated in Singapore. Data on demographic characteristics, common causes (mostly falls and traffic accidents), types of spinal damage, and outcomes are reported. Following rehabilitation, 68 patients were able to ambulate independently and 45 patients achieved independence in activities of daily…

A work study of the CAD/CAM method and conventional manual method in the fabrication of spinal orthoses for patients with adolescent idiopathic scoliosis.

PubMed

Wong, M S; Cheng, J C Y; Wong, M W; So, S F

2005-04-01

A study was conducted to compare the CAD/CAM method with the conventional manual method in fabrication of spinal orthoses for patients with adolescent idiopathic scoliosis. Ten subjects were recruited for this study. Efficiency analyses of the two methods were performed from cast filling/ digitization process to completion of cast/image rectification. The dimensional changes of the casts/ models rectified by the two cast rectification methods were also investigated. The results demonstrated that the CAD/CAM method was faster than the conventional manual method in the studied processes. The mean rectification time of the CAD/CAM method was shorter than that of the conventional manual method by 108.3 min (63.5%). This indicated that the CAD/CAM method took about 1/3 of the time of the conventional manual to finish cast rectification. In the comparison of cast/image dimensional differences between the conventional manual method and the CAD/CAM method, five major dimensions in each of the five rectified regions namely the axilla, thoracic, lumbar, abdominal and pelvic regions were involved. There were no significant dimensional differences (p < 0.05) in 19 out of the 25 studied dimensions. This study demonstrated that the CAD/CAM system could save the time in the rectification process and offer a relatively high resemblance in cast rectification as compared with the conventional manual method.

Idiopathic Parkinson's disease: possible routes by which vulnerable neuronal types may be subject to neuroinvasion by an unknown pathogen.

PubMed

Braak, H; Rüb, U; Gai, W P; Del Tredici, K

2003-05-01

The progressive, neurodegenerative process underlying idiopathic Parkinson's disease is associated with the formation of proteinaceous inclusion bodies that involve a few susceptible neuronal types of the human nervous system. In the lower brain stem, the process begins in the dorsal motor nucleus of the vagus nerve and advances from there essentially upwards through susceptible regions of the medulla oblongata, pontine tegmentum, midbrain, and basal forebrain until it reaches the cerebral cortex. With time, multiple components of the autonomic, limbic, and motor systems become severely impaired. All of the vulnerable subcortical grays and cortical areas are closely interconnected. Incidental cases of idiopathic Parkinson's disease may show involvement of both the enteric nervous system and the dorsal motor nucleus of the vagus nerve. This observation, combined with the working hypothesis that the stereotypic topographic expansion pattern of the lesions may resemble that of a falling row of dominos, prompts the question whether the disorder might originate outside of the central nervous system, caused by a yet unidentified pathogen that is capable of passing the mucosal barrier of the gastrointestinal tract and, via postganglionic enteric neurons, entering the central nervous system along unmyelinated praeganglionic fibers generated from the visceromotor projection cells of the vagus nerve. By way of retrograde axonal and transneuronal transport, such a causative pathogen could reach selectively vulnerable subcortical nuclei and, unimpeded, gain access to the cerebral cortex. The here hypothesized mechanism offers one possible explanation for the sequential and apparently uninterrupted manner in which vulnerable brain regions, subcortical grays and cortical areas become involved in idiopathic Parkinson's disease.

Sagittal balance and idiopathic scoliosis: does final sagittal alignment influence outcomes, degeneration rate or failure rate?

PubMed

Ilharreborde, Brice

2018-02-01

In the last decade, spine surgeons have been impacted by the "sagittal plane analysis revolution". Significant correlations have been found in adult spinal deformity (ASD) between sagittal lumbo-pelvic parameters and functional outcomes, but most of them do not apply in adolescent idiopathic scoliosis (AIS). Meanwhile, instrumentation and reduction strategies have considerably evolved. This paper aims to describe the preoperative sagittal alignment in AIS, and to report literature evidence regarding the influence of postoperative sagittal balance on complication rates, low back pain incidence and disc degeneration. A bibliographic search in Medline and Google database from 1984 to May 2017 was performed. The keywords included 'adolescent idiopathic scoliosis', 'adult scoliosis', 'sagittal alignment', 'proximal junctional kyphosis', 'distal junctional kyphosis', 'outcomes', 'low back pain' and 'complication', used individually or in combination. Algorithms of sagittal balance analysis and treatment decision have been reported in ASD, but the clinical situation is very different in children. Sagittal alignment greatly varies in AIS among the various Lenke types. Most patients are clinically balanced before surgery, but the spinal harmony is altered, with overgrowth of the anterior column and global sagittal flattening (undersestimated in 2D). The exact role of pelvic incidence and whether or not patients also use pelvic compensation to maintain balance still require further clarification. The incidence of radiological junctional failures remains highly variable, depending on definitions, cohort size and follow-up. Preoperative hyperkyphosis seems to be a consistent and relevant risk factor. Current literature does not support the recent trend to save motion segments (selective fusion), and no significant association was found between the distal level of fusion and the incidence of low back pain. Postoperative sagittal alignment seems to be more important than LIV

The lemon illusion: seeing curvature where there is none.

PubMed

Strother, Lars; Killebrew, Kyle W; Caplovitz, Gideon P

2015-01-01

Curvature is a highly informative visual cue for shape perception and object recognition. We introduce a novel illusion-the Lemon Illusion-in which subtle illusory curvature is perceived along contour regions that are devoid of physical curvature. We offer several perceptual demonstrations and observations that lead us to conclude that the Lemon Illusion is an instance of a more general illusory curvature phenomenon, one in which the presence of contour curvature discontinuities lead to the erroneous extension of perceived curvature. We propose that this erroneous extension of perceived curvature results from the interaction of neural mechanisms that operate on spatially local contour curvature signals with higher-tier mechanisms that serve to establish more global representations of object shape. Our observations suggest that the Lemon Illusion stems from discontinuous curvature transitions between rectilinear and curved contour segments. However, the presence of curvature discontinuities is not sufficient to produce the Lemon Illusion, and the minimal conditions necessary to elicit this subtle and insidious illusion are difficult to pin down.

The role of curvature in entanglement

NASA Astrophysics Data System (ADS)

Buck, Gregory

2015-10-01

Which tangles more readily: curly hair or straight hair? A perhaps natural thought, supported by some theoretical evidence, is to associate curvature and entanglement, and assume that they would grow together-that an increase in one fosters an increase in the other. However we have biological examples such as DNA in the chromosome, and mechanical examples such as coiled telephone cords, in which much more curvature is employed than is required for the packing, and in which tangling is presumably detrimental. We offer a resolution to this conundrum. We show, that at least for simple but generally applicable models, the relationship between curvature and entanglement is subtle: if we keep filament density constant and increase curvature, the entanglement initially increases, passes through a maximum, then decreases, so there is a regime where increasing curvature increases entanglement, and there is also a regime where increasing curvature decreases entanglement. This has implications for filament packing in many circumstances, and in particular for the compaction structure of DNA in the cell-it provides a straightforward argument for the view that one purpose of DNA coiling and supercoiling is to inhibit entanglement. It also tells us to expect that wavy hair-neither the straightest nor the curliest-tangles most readily.

Update on diagnosis and treatment of idiopathic pulmonary fibrosis

PubMed Central

Baddini-Martinez, José; Baldi, Bruno Guedes; da Costa, Cláudia Henrique; Jezler, Sérgio; Lima, Mariana Silva; Rufino, Rogério

2015-01-01

Idiopathic pulmonary fibrosis is a type of chronic fibrosing interstitial pneumonia, of unknown etiology, which is associated with a progressive decrease in pulmonary function and with high mortality rates. Interest in and knowledge of this disorder have grown substantially in recent years. In this review article, we broadly discuss distinct aspects related to the diagnosis and treatment of idiopathic pulmonary fibrosis. We list the current diagnostic criteria and describe the therapeutic approaches currently available, symptomatic treatments, the action of new drugs that are effective in slowing the decline in pulmonary function, and indications for lung transplantation. PMID:26578138

Lenke and King classification systems for adolescent idiopathic scoliosis: interobserver agreement and postoperative results

PubMed Central

Hosseinpour-Feizi, Hojjat; Soleimanpour, Jafar; Sales, Jafar Ganjpour; Arzroumchilar, Ali

2011-01-01

Purpose The aim of this study was to investigate the interobserver agreement of the Lenke and King classifications for adolescent idiopathic scoliosis, and to compare the results of surgery performed based on classification of the scoliosis according to each of these classification systems. Methods The study was conducted in Shohada Hospital in Tabriz, Iran, between 2009 and 2010. First, a reliability assessment was undertaken to assess interobserver agreement of the Lenke and King classifications for adolescent idiopathic scoliosis. Second, postoperative efficacy and safety of surgery performed based on the Lenke and King classifications were compared. Kappa coefficients of agreement were calculated to assess the agreement. Outcomes were compared using bivariate tests and repeated measures analysis of variance. Results A low to moderate interobserver agreement was observed for the King classification; the Lenke classification yielded mostly high agreement coefficients. The outcome of surgery was not found to be substantially different between the two systems. Conclusion Based on the results, the Lenke classification method seems advantageous. This takes into consideration the Lenke classification’s priority in providing details of curvatures in different anatomical surfaces to explain precise intensity of scoliosis, that it has higher interobserver agreement scores, and also that it leads to noninferior postoperative results compared with the King classification method. PMID:22267934

Lenke and King classification systems for adolescent idiopathic scoliosis: interobserver agreement and postoperative results.

PubMed

Hosseinpour-Feizi, Hojjat; Soleimanpour, Jafar; Sales, Jafar Ganjpour; Arzroumchilar, Ali

2011-01-01

The aim of this study was to investigate the interobserver agreement of the Lenke and King classifications for adolescent idiopathic scoliosis, and to compare the results of surgery performed based on classification of the scoliosis according to each of these classification systems. The study was conducted in Shohada Hospital in Tabriz, Iran, between 2009 and 2010. First, a reliability assessment was undertaken to assess interobserver agreement of the Lenke and King classifications for adolescent idiopathic scoliosis. Second, postoperative efficacy and safety of surgery performed based on the Lenke and King classifications were compared. Kappa coefficients of agreement were calculated to assess the agreement. Outcomes were compared using bivariate tests and repeated measures analysis of variance. A low to moderate interobserver agreement was observed for the King classification; the Lenke classification yielded mostly high agreement coefficients. The outcome of surgery was not found to be substantially different between the two systems. Based on the results, the Lenke classification method seems advantageous. This takes into consideration the Lenke classification's priority in providing details of curvatures in different anatomical surfaces to explain precise intensity of scoliosis, that it has higher interobserver agreement scores, and also that it leads to noninferior postoperative results compared with the King classification method.

The contribution of the SPINK1 c.194+2T>C mutation to the clinical course of idiopathic chronic pancreatitis in Chinese patients.

PubMed

Sun, Chang; Liao, Zhuan; Jiang, Lili; Yang, Fu; Xue, Geng; Zhou, Qi; Chen, Ruiwen; Sun, Shuhan; Li, Zhaoshen

2013-01-01

Recent data suggest that the serine protease inhibitor Kazal type 1 (SPINK1) gene mutation is associated with idiopathic chronic pancreatitis. However, few studies have focused on the serine protease inhibitor Kazal type 1 c.194+2T>C mutation. Therefore, our goal was to study the prevalence and impact of serine protease inhibitor Kazal type 1 mutations on the clinical profile of idiopathic chronic pancreatitis patients in China. A retrospective-cohort study of 118 Chinese patients with idiopathic chronic pancreatitis was performed, and genetic tests were carried out to detect SPINK1 mutations. Subjects without pancreatitis were used as controls. In total, 118 idiopathic chronic pancreatitis patients and 100 control subjects were evaluated. The serine protease inhibitor Kazal type 1 c.194+2T>C variant was present in 44.9% of patients with idiopathic chronic pancreatitis. The frequency of diabetes in idiopathic chronic pancreatitis patients with the serine protease inhibitor Kazal type 1 c.194+2T>C mutation (39.6%) was higher than that of patients without the mutation (9.2%). The time to occurrence of diabetes mellitus after idiopathic chronic pancreatitis symptom onset is significantly influenced by the c.194+2T>C mutation (p<0.001). In addition, the mean age of diabetes onset in patients with the serine protease inhibitor Kazal type 1 c.194+2T>C mutation (38.33 ± 9.50) was significantly younger than that of patients without this mutation (49.67 ± 6.74). The presence of the serine protease inhibitor Kazal type 1 c.194+2T>C mutation seems to be associated with idiopathic chronic pancreatitis and could predispose individuals to pancreatic diabetes onset at an earlier age. Copyright © 2012 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Quantitative evaluation of the lumbosacral sagittal alignment in degenerative lumbar spinal stenosis

PubMed Central

Makirov, Serik K.; Jahaf, Mohammed T.; Nikulina, Anastasia A.

2015-01-01

LSB of 0.2 or less, so this value can be predictable for its development. It may suggest that spinal stenosis is more likely to occur in patients with the spinal curvature of this type because of abnormal distribution of the spine loads. This fact may have prognostic significance for develop vertebral column disease and evaluation of treatment results. PMID:26767160

AMSARA: Accession Medical Standards Analysis and Research Activity. Report of 2007 Attrition and Morbidity Data for 2006 Accessions

DTIC Science & Technology

2008-08-04

31 43.7 Available data for curve types (i.e. scoliosis, kyphosis, lordosis ) and subtypes of scoliosis (i.e. thoracic, lumbar, thoracolumbar, double...1% were lordosis . Among scoliosis subtypes, double major curves were the most prevalent (19% of all cases), followed by thoracic, thoracolumbar, and...lumbar. 8 FIGURE 1.2 SPINAL CURVATURE TYPES AND SCOLIOSIS SUBTYPES FORSPINAL CURVATURE EPTS DISCHARGES (2006) N = 71 Lordosis 1% Kyphosis_ 11

The influence of reed curvature on the tone quality of lingual organ pipes

NASA Astrophysics Data System (ADS)

Plitnik, G. R.; Angster, J.

2002-11-01

Given certain design constraints, such as the type of stop being voiced and the desired tone quality, reed voicers must use consummate skill to curve each tongue so as to produce the best and most stable tone, as well as maintaining a consistent tone quality across an entire rank of pipes. The curvature given to a reed tongue influences not only the harmonic structure of the steady-state sound, but also the attack. Two fundamentally different types of curvature are typically employed, the chorus reed (trompette) curve (which yields a bright sound) and the smooth-toned curve employed for solo reeds such as the clarinet. This study investigated the effect of reed curvature on the vibration and tone of reed tongues of both types. Two F2 pipes (a trompette and a clarinet) were constructed and voiced with 6 different tongues each to produce a variety of tones. The reed's vibration was measured under typical conditions by laser vibrometer; the pressure waves in the boot and in the shallot were measured by means of one-eighth inch microphones and the emitted sound was recorded at the egress. By performing various measurements simultaneously, phase differences were also determined.

Three-Dimensional Vertebral Wedging in Mild and Moderate Adolescent Idiopathic Scoliosis

PubMed Central

Scherrer, Sophie-Anne; Begon, Mickaël; Leardini, Alberto; Coillard, Christine; Rivard, Charles-Hilaire; Allard, Paul

2013-01-01

Background Vertebral wedging is associated with spinal deformity progression in adolescent idiopathic scoliosis. Reporting frontal and sagittal wedging separately could be misleading since these are projected values of a single three-dimensional deformation of the vertebral body. The objectives of this study were to determine if three-dimensional vertebral body wedging is present in mild scoliosis and if there are a preferential vertebral level, position and plane of deformation with increasing scoliotic severity. Methodology Twenty-seven adolescent idiopathic scoliotic girls with mild to moderate Cobb angles (10° to 50°) participated in this study. All subjects had at least one set of bi-planar radiographs taken with the EOS® X-ray imaging system prior to any treatment. Subjects were divided into two groups, separating the mild (under 20°) from the moderate (20° and over) spinal scoliotic deformities. Wedging was calculated in three different geometric planes with respect to the smallest edge of the vertebral body. Results Factorial analyses of variance revealed a main effect for the scoliosis severity but no main effect of vertebral Levels (apex and each of the three vertebrae above and below it) (F = 1.78, p = 0.101). Main effects of vertebral Positions (apex and above or below it) (F = 4.20, p = 0.015) and wedging Planes (F = 34.36, p<0.001) were also noted. Post-hoc analysis demonstrated a greater wedging in the inferior group of vertebrae (3.6°) than the superior group (2.9°, p = 0.019) and a significantly greater wedging (p≤0.03) along the sagittal plane (4.3°). Conclusions Vertebral wedging was present in mild scoliosis and increased as the scoliosis progressed. The greater wedging of the inferior group of vertebrae could be important in estimating the most distal vertebral segment to be restrained by bracing or to be fused in surgery. Largest vertebral body wedging values obtained in the sagittal plane support the claim

Gaussian Curvature as an Identifier of Shell Rigidity

NASA Astrophysics Data System (ADS)

Harutyunyan, Davit

2017-11-01

In the paper we deal with shells with non-zero Gaussian curvature. We derive sharp Korn's first (linear geometric rigidity estimate) and second inequalities on that kind of shell for zero or periodic Dirichlet, Neumann, and Robin type boundary conditions. We prove that if the Gaussian curvature is positive, then the optimal constant in the first Korn inequality scales like h, and if the Gaussian curvature is negative, then the Korn constant scales like h 4/3, where h is the thickness of the shell. These results have a classical flavour in continuum mechanics, in particular shell theory. The Korn first inequalities are the linear version of the famous geometric rigidity estimate by Friesecke et al. for plates in Arch Ration Mech Anal 180(2):183-236, 2006 (where they show that the Korn constant in the nonlinear Korn's first inequality scales like h 2), extended to shells with nonzero curvature. We also recover the uniform Korn-Poincaré inequality proven for "boundary-less" shells by Lewicka and Müller in Annales de l'Institute Henri Poincare (C) Non Linear Anal 28(3):443-469, 2011 in the setting of our problem. The new estimates can also be applied to find the scaling law for the critical buckling load of the shell under in-plane loads as well as to derive energy scaling laws in the pre-buckled regime. The exponents 1 and 4/3 in the present work appear for the first time in any sharp geometric rigidity estimate.

Comparison of monocyte gene expression among patients with neurocysticercosis-associated epilepsy, Idiopathic Epilepsy and idiopathic headaches in India.

PubMed

Prabhakaran, Vasudevan; Drevets, Douglas A; Ramajayam, Govindan; Manoj, Josephine J; Anderson, Michael P; Hanas, Jay S; Rajshekhar, Vedantam; Oommen, Anna; Carabin, Hélène

2017-06-01

Neurocysticercosis (NCC), a neglected tropical disease, inflicts substantial health and economic costs on people living in endemic areas such as India. Nevertheless, accurate diagnosis using brain imaging remains poorly accessible and too costly in endemic countries. The goal of this study was to test if blood monocyte gene expression could distinguish patients with NCC-associated epilepsy, from NCC-negative imaging lesion-free patients presenting with idiopathic epilepsy or idiopathic headaches. Patients aged 18 to 51 were recruited from the Department of Neurological Sciences, Christian Medical College and Hospital, Vellore, India, between January 2013 and October 2014. mRNA from CD14+ blood monocytes was isolated from 76 patients with NCC, 10 Recovered NCC (RNCC), 29 idiopathic epilepsy and 17 idiopathic headaches patients. A preliminary microarray analysis was performed on six NCC, six idiopathic epilepsy and four idiopathic headaches patients to identify genes differentially expressed in NCC-associated epilepsy compared with other groups. This analysis identified 1411 upregulated and 733 downregulated genes in patients with NCC compared to Idiopathic Epilepsy. Fifteen genes up-regulated in NCC patients compared with other groups were selected based on possible relevance to NCC, and analyzed by qPCR in all patients' samples. Differential gene expression among patients was assessed using linear regression models. qPCR analysis of 15 selected genes showed generally higher gene expression among NCC patients, followed by RNCC, idiopathic headaches and Idiopathic Epilepsy. Gene expression was also generally higher among NCC patients with single cyst granulomas, followed by mixed lesions and single calcifications. Expression of certain genes in blood monocytes can distinguish patients with NCC-related epilepsy from patients with active Idiopathic Epilepsy and idiopathic headaches. These findings are significant because they may lead to the development of new tools to

On turbulent flows dominated by curvature effects

NASA Technical Reports Server (NTRS)

Cheng, G. C.; Farokhi, S.

1992-01-01

A technique for improving the numerical predictions of turbulent flows with the effect of streamline curvature is developed. Separated flows and the flow in a curved duct are examples of flowfields where streamline curvature plays a dominant role. New algebraic formulations for the eddy viscosity incorporating the k-epsilon turbulence model are proposed to account for various effects of streamline curvature. The loci of flow reversal of the separated flows over various backward-facing steps are employed to test the capability of the proposed turbulence model in capturing the effect of local curvature.

Developmental regulation of N-methyl-D-aspartate- and kainate-type glutamate receptor expression in the rat spinal cord

NASA Technical Reports Server (NTRS)

Stegenga, S. L.; Kalb, R. G.

2001-01-01

Spinal motor neurons undergo experience-dependent development during a critical period in early postnatal life. It has been suggested that the repertoire of glutamate receptor subunits differs between young and mature motor neurons and contributes to this activity-dependent development. In the present study we examined the expression patterns of N-methyl-D-aspartate- and kainate-type glutamate receptor subunits during the postnatal maturation of the spinal cord. Young motor neurons express much higher levels of the N-methyl-D-aspartate receptor subunit NR1 than do adult motor neurons. Although there are eight potential splice variants of NR1, only a subgroup is expressed by motor neurons. With respect to NR2 receptor subunits, young motor neurons express NR2A and C, while adult motor neurons express only NR2A. Young motor neurons express kainate receptor subunits GluR5, 6 and KA2 but we are unable to detect these or any other kainate receptor subunits in the adult spinal cord. Other spinal cord regions display a distinct pattern of developmental regulation of N-methyl-D-aspartate and kainate receptor subunit expression in comparison to motor neurons. Our findings indicate a precise spatio-temporal regulation of individual subunit expression in the developing spinal cord. Specific combinations of subunits in developing neurons influence their excitable properties and could participate in the emergence of adult neuronal form and function.

Spinal Accessory Motor Neurons in the Mouse: A Special Type of Branchial Motor Neuron?

PubMed

Watson, Charles; Tvrdik, Petr

2018-04-16

The spinal accessory nerve arises from motor neurons in the upper cervical spinal cord. The axons of these motor neurons exit dorsal to the ligamentum denticulatum and form the spinal accessory nerve. The nerve ascends in the spinal subarachnoid space to enter the posterior cranial fossa through the foramen magnum. The spinal accessory nerve then turns caudally to exit through the jugular foramen alongside the vagus and glossopharyngeal nerves, and then travels to supply the sternomastoid and trapezius muscles in the neck. The unusual course of the spinal accessory nerve has long prompted speculation that it is not a typical spinal motor nerve and that it might represent a caudal remnant of the branchial motor system. Our cell lineage tracing data, combined with images from public databases, show that the spinal accessory motor neurons in the mouse transiently express Phox2b, a transcription factor that is required for development of brain stem branchial motor nuclei. While this is strong prima facie evidence that the spinal accessory motor neurons should be classified as branchial motor, the evolutionary history of these motor neurons in anamniote vertebrates suggests that they may be considered to be an atypical branchial group that possesses both branchial and somatic characteristics. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Pain is the Greatest Preoperative Concern for Patients and Parents Before Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis.

PubMed

Chan, Priscella; Skaggs, David L; Sanders, Austin E; Villamor, Gabriela A; Choi, Paul D; Tolo, Vernon T; Andras, Lindsay M

2017-11-01

Prospective cross-sectional study. To evaluate patients' and parents' concerns so they can be addressed with appropriate preoperative counseling. Despite much research on outcomes for posterior spinal fusion (PSF) in adolescent idiopathic scoliosis (AIS), little is available about preoperative fears or concerns. Patients with AIS undergoing PSF, their parents, and surgeons were prospectively enrolled and asked to complete a survey on their fears and concerns about surgery at their preoperative appointment. Forty-eight patients and parents completed surveys. Four attending pediatric spine surgeons participated and submitted 48 responses. Mean age of patients was 14.2 years. On a scale of 0 to 10, mean level of concern reported by parents (6.9) was higher than that reported by patients (4.6). Surgeons rated the procedure's complexity on a scale of 0 to 10 and reported a mean of 5.2. Neither patients' nor parents' level of concern correlated with the surgeons' assessment of the procedure's complexity level (R = 0.19 and 0.12, P = 0.20 and P = 0.42, respectively). Top three concerns for patients were pain (25%), ability to return to activities (21%), and neurologic injury (17%). Top three concerns for parents were pain (35%), neurologic injury (21%), and amount of correction (17%). Top three concerns for surgeons were postoperative shoulder balance (44%), neurologic injury (27%), and lowest instrumented vertebrae selection (27%). Patients reported the same concerns 23% of the time as parents, and 17% of the time as surgeons. Parents and surgeons reported the same concerns 21% of the time. Pain was the greatest concern for both patients and parents but was rarely listed as a concern by surgeons. Parent and patient level of concern did not correlate to the surgeon's assessment of the procedure's complexity. Neurologic injury was a top concern for all groups, but otherwise there was little overlap between physician, patient, and parent concerns. 3.

Axial Plane Deformity of the Shoulder in Adolescent Idiopathic Scoliosis.

PubMed

Menon, Venugopal K; Tahasildar, Naveen; Pillay, Haroon M; M, Anbuselvam

2017-05-01

Prospective observational study. To study axial plane deformation of the shoulder in adolescent idiopathic scoliosis (AIS) and try to correlate it with curve type and surgical correction. It is established that AIS is a 3-dimensional deformity. The rib hump is the most common manifestation of axial plane deformations; the least common manifestation seems to be upper trunk and shoulder rotation, which has been hitherto undescribed. Fourteen consecutive, operated cases of AIS were analyzed prospectively. Preoperative and postoperative x-rays of the spine and clinical photographs were studied. Clinical photographs (top view) were taken with patients in the sitting position, to show shoulder level in relation to the axis of the head and pelvis. Chest computed tomography scans were also studied to determine the direction of apical vertebra and trunk torsion. All 14 patients in this series had their right shoulders anteriorly rotated preoperatively (anticlockwise). The direction of rotation seemed unrelated to the curve type and shoulder elevation, although most had rib humps on the right. This shoulder rotation was corrected postoperatively by routine maneuvers done for scoliosis correction. Minor residual rotation was seen in 6 patients who also had minimal persisting rib hump. In 1 case the axial plane rotation worsened, although the shoulder level and trunk symmetry improved significantly. The apical vertebral rotation on computed tomography had little bearing on the direction of shoulder rotation. Axial plane rotation of the shoulder is a hitherto un-described dimension of AIS deformity complex. Much of it corrects spontaneously with correction of the thoracic spinal deformity.

Clinical validation of coronal and sagittal spinal curve measurements based on three-dimensional vertebra vector parameters.

PubMed

Somoskeöy, Szabolcs; Tunyogi-Csapó, Miklós; Bogyó, Csaba; Illés, Tamás

2012-10-01

For many decades, visualization and evaluation of three-dimensional (3D) spinal deformities have only been possible by two-dimensional (2D) radiodiagnostic methods, and as a result, characterization and classification were based on 2D terminologies. Recent developments in medical digital imaging and 3D visualization techniques including surface 3D reconstructions opened a chance for a long-sought change in this field. Supported by a 3D Terminology on Spinal Deformities of the Scoliosis Research Society, an approach for 3D measurements and a new 3D classification of scoliosis yielded several compelling concepts on 3D visualization and new proposals for 3D classification in recent years. More recently, a new proposal for visualization and complete 3D evaluation of the spine by 3D vertebra vectors has been introduced by our workgroup, a concept, based on EOS 2D/3D, a groundbreaking new ultralow radiation dose integrated orthopedic imaging device with sterEOS 3D spine reconstruction software. Comparison of accuracy, correlation of measurement values, intraobserver and interrater reliability of methods by conventional manual 2D and vertebra vector-based 3D measurements in a routine clinical setting. Retrospective, nonrandomized study of diagnostic X-ray images created as part of a routine clinical protocol of eligible patients examined at our clinic during a 30-month period between July 2007 and December 2009. In total, 201 individuals (170 females, 31 males; mean age, 19.88 years) including 10 healthy athletes with normal spine and patients with adolescent idiopathic scoliosis (175 cases), adult degenerative scoliosis (11 cases), and Scheuermann hyperkyphosis (5 cases). Overall range of coronal curves was between 2.4 and 117.5°. Analysis of accuracy and reliability of measurements was carried out on a group of all patients and in subgroups based on coronal plane deviation: 0 to 10° (Group 1; n=36), 10 to 25° (Group 2; n=25), 25 to 50° (Group 3; n=69), 50 to 75�

Nonadditive Compositional Curvature Energetics of Lipid Bilayers

NASA Astrophysics Data System (ADS)

Sodt, A. J.; Venable, R. M.; Lyman, E.; Pastor, R. W.

2016-09-01

The unique properties of the individual lipids that compose biological membranes together determine the energetics of the surface. The energetics of the surface, in turn, govern the formation of membrane structures and membrane reshaping processes, and thus they will underlie cellular-scale models of viral fusion, vesicle-dependent transport, and lateral organization relevant to signaling. The spontaneous curvature, to the best of our knowledge, is always assumed to be additive. We describe observations from simulations of unexpected nonadditive compositional curvature energetics of two lipids essential to the plasma membrane: sphingomyelin and cholesterol. A model is developed that connects molecular interactions to curvature stress, and which explains the role of local composition. Cholesterol is shown to lower the number of effective Kuhn segments of saturated acyl chains, reducing lateral pressure below the neutral surface of bending and favoring positive curvature. The effect is not observed for unsaturated (flexible) acyl chains. Likewise, hydrogen bonding between sphingomyelin lipids leads to positive curvature, but only at sufficient concentration, below which the lipid prefers negative curvature.

Plan curvature and landslide probability in regions dominated by earth flows and earth slides

USGS Publications Warehouse

Ohlmacher, G.C.

2007-01-01

Damaging landslides in the Appalachian Plateau and scattered regions within the Midcontinent of North America highlight the need for landslide-hazard mapping and a better understanding of the geomorphic development of landslide terrains. The Plateau and Midcontinent have the necessary ingredients for landslides including sufficient relief, steep slope gradients, Pennsylvanian and Permian cyclothems that weather into fine-grained soils containing considerable clay, and adequate precipitation. One commonly used parameter in landslide-hazard analysis that is in need of further investigation is plan curvature. Plan curvature is the curvature of the hillside in a horizontal plane or the curvature of the contours on a topographic map. Hillsides can be subdivided into regions of concave outward plan curvature called hollows, convex outward plan curvature called noses, and straight contours called planar regions. Statistical analysis of plan-curvature and landslide datasets indicate that hillsides with planar plan curvature have the highest probability for landslides in regions dominated by earth flows and earth slides in clayey soils (CH and CL). The probability of landslides decreases as the hillsides become more concave or convex. Hollows have a slightly higher probability for landslides than noses. In hollows landslide material converges into the narrow region at the base of the slope. The convergence combined with the cohesive nature of fine-grained soils creates a buttressing effect that slows soil movement and increases the stability of the hillside within the hollow. Statistical approaches that attempt to determine landslide hazard need to account for the complex relationship between plan curvature, type of landslide, and landslide susceptibility. ?? 2007 Elsevier B.V. All rights reserved.

[Application of surface electromyography in the treatment of adolescent idiopathic scoliosis with traditional spinal balanced therapy].

PubMed

Du, Hong-Gen; Ye, Shu-Liang; Xu, Jin-Yuan; Jiang, Zhong; Song, Hong-Quan; Yu, Ji-Wei

2013-11-01

To evaluate the values of surface electromyography (sEMG) in the treatment of adolescent idiophathic scoliosis (AIS) with non-surgical therapy. From October 2011 to May 2012, the data of 33 patients with AIS underwent traditional spinal balanced therapy were analyzed. There were 14 males and 19 females with an average age of (15.40 +/- 3.01) years,ranging in Cobb angle from 13 degrees to 40 degrees, course of disease more than 3 months. X-rays showed 21 cases were type C and 9 cases were type S. Preoperative and postoperative 6 months, Cobb angle, the ratio of averaged electromyography paramete (AEMG), security of treatment were observed. Thirty cases (90.9%) accomplished the treatment and detection. No harmful effects to vital sign was found and no fracture, dislocation, apopsychia, infection of pin hole was found. There was positive correlation between the ratio of AEMG and Cobb angle (P = 0.003). The ratio of AEMG decreased after treatment,and indicated the improvement of myosthenic otherness. sEMG can be used as a objective examination in evaluating difference of muscle electricity activity on both concaved and convex sides for patients of AIS, so it is a qualified objective examination for effectiveness evaluation and assessment aggravation risk, and has great value in clinic.

Active matter and Curvature

NASA Astrophysics Data System (ADS)

Sknepnek, Rastko

Coupling between active motion and curvature is an integral part of many fundamental biological processes such as gastrulation and intestinal crypt fission. However, to date very little is known about how curvature affects active motion. Here we use a particle-based model to study the interplay between activity and curvature in dense systems. Using detailed numerical simulations and simple physical arguments, we show that the presence of curvature results in a number of steady-state configurations that have no analogues in flat geometries. These states are particularly interesting if topological constraints require the presence of defects in the ground states in the passive limit. We focus on polar and nematic active systems confined to move on the surface of a sphere and show that activity can lead to the formation of moving band and multidefect states. We extend our model to self-propelled filaments confined to a plane or the surface of a sphere. We show that the activity leads to an effective softening of the polymer chain. As a result of this softening, with the increase in activity, the system transitions between a jammed polymer-melt state, an active turbulent state characterised by a proliferation of hair-pin defects, to a region dominated by phase segregation (MIPS), finally followed by the onset of a homogenous state characterised by spiral motion of individual polymers. UK EPSRC EP/M009599/1.

A Comparative Study on the Role of Xpert MTB/RIF in Testing Different Types of Spinal Tuberculosis Tissue Specimens.

PubMed

Tang, Liang; Feng, Shiqing; Gao, Ruixiao; Han, Chenfu; Sun, Xiaochen; Bao, Yucheng; Zhang, Wenlong

2017-12-01

The aim of the present study was to compare the efficacy of the commercial Xpert Mycobacterium tuberculosis/rifampin (MTB/RIF) test for evaluating different types of spinal tuberculosis (TB) tissue specimens. Pus, granulation tissue, and caseous necrotic tissue specimens from 223 patients who were diagnosed with spinal TB and who underwent curettage were collected for bacterial culture and the Xpert MTB/RIF assay to calculate the positive rate. Bacterial culture and phenotypic drug sensitivity testing (pDST) were adopted as the gold standards to calculate the sensitivity and specificity of the Xpert bacterial detection and drug resistance (DR) test. The positive rate (68.61% ± 7.35%) from the Xpert MTB/RIF assays of spinal TB patients' tissue specimens was higher compared with bacterial culture (44.39% ± 6.51%, Z = 5.1642, p < 0.01), and the positive rates from Xpert MTB/RIF assays on the three types of specimens were all higher than those of bacterial culture, with statistically significant results for pus and granulation tissue specimens. The positive rates for pus using the two bacteriological tests were higher than those for granulation tissue but were not statistically significant. However, the positive rates obtained from granulation tissue were statistically significantly higher than those obtained from caseous necrotic tissue. With bacterial culture and pDST as the gold standards, the sensitivity of Xpert MTB/RIF assays for MTB was 96.97%, while the sensitivity and specificity of the DR test also remained relatively high. For efficient and accurate diagnosis of spinal TB and DR and timely provision of effective treatment, multiple specimens, especially the pus of spinal TB patients, should be collected for Xpert MTB/RIF assays.

Curvature methods of damage detection using digital image correlation

NASA Astrophysics Data System (ADS)

Helfrick, Mark N.; Niezrecki, Christopher; Avitabile, Peter

2009-03-01

Analytical models have shown that local damage in a structure can be detected by studying changes in the curvature of the structure's displaced shape while under an applied load. In order for damage to be detected, located, and quantified using curvature methods, a spatially dense set of measurement points is required on the structure of interest and the change in curvature must be measurable. Experimental testing done to validate the theory is often plagued by sparse data sets and experimental noise. Furthermore, the type of load, the location and severity of the damage, and the mechanical properties (material and geometry) of the structure have a significant effect on how much the curvature will change. Within this paper, three-dimensional (3D) Digital Image Correlation (DIC) as one possible method for detecting damage through curvature methods is investigated. 3D DIC is a non-contacting full-field measurement technique which uses a stereo pair of digital cameras to capture surface shape. This approach allows for an extremely dense data set across the entire visible surface of an object. A test is performed to validate the approach on an aluminum cantilever beam. A dynamic load is applied to the beam which allows for measurements to be made of the beam's response at each of its first three resonant frequencies, corresponding to the first three bending modes of the structure. DIC measurements are used with damage detection algorithms to predict damage location with varying levels of damage inflicted in the form of a crack with a prescribed depth. The testing demonstrated that this technique will likely only work with structures where a large displaced shape is easily achieved and in cases where the damage is relatively severe. Practical applications and limitations of the technique are discussed.

Analysis of dynamic smile and upper lip curvature in young Chinese

PubMed Central

Liang, Ling-Zhi; Hu, Wen-Jie; Zhang, Yan-Ling; Chung, Kwok-Hung

2013-01-01

During smile evaluation and anterior esthetic construction, the anatomic and racial variations should be considered in order to achieve better matching results. The aims of this study were to validate an objective method for recording spontaneous smile process and to categorize the smile and upper lip curvature of Chinese Han-nationality youth. One hundred and eighty-eight Chinese Han-nationality youths (88 males and 100 females) ranged from 20 to 35 years of age were selected. Spontaneous smiles were elicited by watching comical movies and the dynamics of the spontaneous smile were captured continuously with a digital video camera. All subjects' smiles were categorized into three types: commissure, cuspid and gummy smile based on video editing software and final images. Subjects' upper lip curvatures were also measured and divided into three groups: upward, straight and downward. Reliability analysis was conducted to obtain intra-rater reliabilities on twice measurements. The Pearson Chi-square test was used to compare differences for each parameters (α=0.05). In smile classification, 60.6% commissure smile, 33.5% cuspid smile and 5.9% gummy smile were obtained. In upper lip measurement, 26.1% upward, 39.9% straight and 34.0% downward upper lip curvature were determined. The commissure smile group showed statistically significant higher percentage of straight (46.5%) and upward (40.4%) in upper lip curvatures (P<0.05), while cuspid smile group (65.1%) and gummy smile group (72.7%) showed statistically significant higher frequency in downward upper lip curvature (P<0.05). It is evident that differences in upper lip curvature and smile classification exist based on race, when comparing Chinese subjects with those of Caucasian descent, and gender. PMID:23558343

Mean cortical curvature reflects cytoarchitecture restructuring in mild traumatic brain injury

PubMed Central

King, Jace B.; Lopez-Larson, Melissa P.; Yurgelun-Todd, Deborah A.

2016-01-01

In the United States alone, the number of persons living with the enduring consequences of traumatic brain injuries is estimated to be between 3.2 and 5 million. This number does not include individuals serving in the United States military or seeking care at Veterans Affairs hospitals. The importance of understanding the neurobiological consequences of mild traumatic brain injury (mTBI) has increased with the return of veterans from conflicts overseas, many of who have suffered this type of brain injury. However, identifying the neuroanatomical regions most affected by mTBI continues to prove challenging. The aim of this study was to assess the use of mean cortical curvature as a potential indicator of progressive tissue loss in a cross-sectional sample of 54 veterans with mTBI compared to 31 controls evaluated with MRI. It was hypothesized that mean cortical curvature would be increased in veterans with mTBI, relative to controls, due in part to cortical restructuring related to tissue volume loss. Mean cortical curvature was assessed in 60 bilateral regions (31 sulcal, 29 gyral). Of the 120 regions investigated, nearly 50% demonstrated significantly increased mean cortical curvature in mTBI relative to controls with 25% remaining significant following multiple comparison correction (all, pFDR < .05). These differences were most prominent in deep gray matter regions of the cortex. Additionally, significant relationships were found between mean cortical curvature and gray and white matter volumes (all, p < .05). These findings suggest potentially unique patterns of atrophy by region and indicate that changes in brain microstructure due to mTBI are sensitive to measures of mean curvature. PMID:26909332

Mean cortical curvature reflects cytoarchitecture restructuring in mild traumatic brain injury.

PubMed

King, Jace B; Lopez-Larson, Melissa P; Yurgelun-Todd, Deborah A

2016-01-01

In the United States alone, the number of persons living with the enduring consequences of traumatic brain injuries is estimated to be between 3.2 and 5 million. This number does not include individuals serving in the United States military or seeking care at Veterans Affairs hospitals. The importance of understanding the neurobiological consequences of mild traumatic brain injury (mTBI) has increased with the return of veterans from conflicts overseas, many of who have suffered this type of brain injury. However, identifying the neuroanatomical regions most affected by mTBI continues to prove challenging. The aim of this study was to assess the use of mean cortical curvature as a potential indicator of progressive tissue loss in a cross-sectional sample of 54 veterans with mTBI compared to 31 controls evaluated with MRI. It was hypothesized that mean cortical curvature would be increased in veterans with mTBI, relative to controls, due in part to cortical restructuring related to tissue volume loss. Mean cortical curvature was assessed in 60 bilateral regions (31 sulcal, 29 gyral). Of the 120 regions investigated, nearly 50% demonstrated significantly increased mean cortical curvature in mTBI relative to controls with 25% remaining significant following multiple comparison correction (all, pFDR < .05). These differences were most prominent in deep gray matter regions of the cortex. Additionally, significant relationships were found between mean cortical curvature and gray and white matter volumes (all, p < .05). These findings suggest potentially unique patterns of atrophy by region and indicate that changes in brain microstructure due to mTBI are sensitive to measures of mean curvature.

Curvature and torsion in growing actin networks

NASA Astrophysics Data System (ADS)

Shaevitz, Joshua W.; Fletcher, Daniel A.

2008-06-01

Intracellular pathogens such as Listeria monocytogenes and Rickettsia rickettsii move within a host cell by polymerizing a comet-tail of actin fibers that ultimately pushes the cell forward. This dense network of cross-linked actin polymers typically exhibits a striking curvature that causes bacteria to move in gently looping paths. Theoretically, tail curvature has been linked to details of motility by considering force and torque balances from a finite number of polymerizing filaments. Here we track beads coated with a prokaryotic activator of actin polymerization in three dimensions to directly quantify the curvature and torsion of bead motility paths. We find that bead paths are more likely to have low rather than high curvature at any given time. Furthermore, path curvature changes very slowly in time, with an autocorrelation decay time of 200 s. Paths with a small radius of curvature, therefore, remain so for an extended period resulting in loops when confined to two dimensions. When allowed to explore a three-dimensional (3D) space, path loops are less evident. Finally, we quantify the torsion in the bead paths and show that beads do not exhibit a significant left- or right-handed bias to their motion in 3D. These results suggest that paths of actin-propelled objects may be attributed to slow changes in curvature, possibly associated with filament debranching, rather than a fixed torque.

Serine Protease Inhibitor Kazal Type 1 (SPINK1) c.194+2T > C Mutation May Predict Long-term Outcome of Endoscopic Treatments in Idiopathic Chronic Pancreatitis.

PubMed

Sun, Chang; Liu, Mu-Yun; Liu, Xiao-Gang; Hu, Liang-Hao; Xia, Tian; Liao, Zhuan; Li, Zhao-Shen

2015-11-01

Endoscopic interventional is a commonly used treatment method for idiopathic chronic pancreatitis. Serine protease inhibitor Kazal type 1 (SPINK1) 194+2T>C mutation is most frequently observed in Chinese pancreatitis patients and influences the clinical course of idiopathic chronic pancreatitis patients. We conducted this study to determine the impacts of this mutation on the outcome of endoscopic treatments.In this study, we enrolled 423 patients. Among them, 101 idiopathic chronic pancreatitis patients without other relevant mutations had a successful endoscopic procedure and completed follow-up. Clinical characteristics including Izbicki pain score, exocrine and endocrine function, were evaluated. Genetic sequencing was conducted to detect SPINK1 194+2T>C mutations.The c.194+2T>C mutation was found in 58 (57.43%) patients. Factors relevant to pain relief are c.194+2T>C mutation (P = 0.011), severe pain before treatment (P = 0.005), and necessary subsequent endoscopic treatments (P < 0.001). More patients with the intronic mutation had deteriorated endocrine function (P = 0.001) relative to those patients without the mutation.Patients carrying the c.194+2T>C mutation were less likely to achieve pain relief through endoscopic treatments. They also have a higher risk of endocrine function deterioration. SPINK1 c.194+2T>C mutation may be applied as a pretreatment predictor in idiopathic chronic pancreatitis patients.

Lipids, curvature, and nano-medicine*

PubMed Central

Mouritsen, Ole G

2011-01-01

The physical properties of the lamellar lipid-bilayer component of biological membranes are controlled by a host of thermodynamic forces leading to overall tensionless bilayers with a conspicuous lateral pressure profile and build-in curvature-stress instabilities that may be released locally or globally in terms of morphological changes. In particular, the average molecular shape and the propensity of the different lipid and protein species for forming non-lamellar and curved structures are a source of structural transitions and control of biological function. The effects of different lipids, sterols, and proteins on membrane structure are discussed and it is shown how one can take advantage of the curvature-stress modulations brought about by specific molecular agents, such as fatty acids, lysolipids, and other amphiphilic solutes, to construct intelligent drug-delivery systems that function by enzymatic triggering via curvature. Practical applications: The simple concept of lipid molecular shape and how it impacts on the structure of lipid aggregates, in particular the curvature and curvature stress in lipid bilayers and liposomes, can be exploited to construct liposome-based drug-delivery systems, e.g., for use as nano-medicine in cancer therapy. Non-lamellar-forming lysolipids and fatty acids, some of which may be designed to be prodrugs, can be created by phospholipase action in diseased tissues thereby providing for targeted drug release and proliferation of molecular entities with conical shape that break down the permeability barrier of the target cells and may hence enhance efficacy. PMID:22164124

Eddy-Current Measurement Of Turning Or Curvature

NASA Technical Reports Server (NTRS)

Chern, Engmin J.

1993-01-01

Rotatable conductive plate covers sensing coil to varying degree. Curvature of pipe at remote or otherwise inaccessible location inside pipe measured using relatively simple angular-displacement eddy-current probe. Crawler and sensor assemblies move along inside of pipe on wheels. Conductive plate pivots to follow curvature of pipe, partly covering one of eddy-current coils to degree depending on local curvature on pipe.

Proximal Junctional Failure After Long-Segment Instrumentation for Degenerative Lumbar Kyphosis With Ankylosing Spinal Disorder.

PubMed

Ikegami, Daisuke; Matsuoka, Takashi; Miyoshi, Yuji; Murata, Yoichi; Aoki, Yasuaki

2015-06-15

Case report. We report a case of proximal junctional failure at the ankylosed, but not the mobile, junction after segmental instrumented fusion for degenerative lumbar kyphosis with ankylosing spinal disorder. Proximal junctional failure (PJF) and proximal junctional kyphosis (PJK) are important complications that occur subsequent to long-segment instrumentation for correction of adult spinal deformity. Thus far, most studies have focused on the mobile junction as a site at which PJK/PJF can occur, and little is known about the relationship between PJK/PJF and ankylosing spinal disorders such as diffuse idiopathic skeletal hyperostosis. The patient was an 82-year-old female with degenerative lumbar kyphosis. She had abnormal confluent hyperostosis in the anterior longitudinal ligaments from Th5 to Th10. The patient was treated operatively with spinal instrumented fusion from Th10 to the sacrum. Four weeks subsequent to initial surgery, the patient developed progressive lower extremity paresis caused by the uppermost instrumented vertebrae fracture (Th10) and adjacent subluxation (Th9). Extension of fusion to Th5 with decompression at Th9-Th10 was performed. However, the patient showed no improvement in neurological function. PJF can occur at the ankylosing site above the uppermost instrumented vertebrae after long-segment instrumentation for adult spinal deformity. PJF in the ankylosed spine may cause severe fracture instability and cord deficit. The ankylosed spine should be integrated into the objective determination of materials contributing to the appropriate selection of fusion levels. 3.

Balancing anisotropic curvature with gauge fields in a class of shear-free cosmological models

NASA Astrophysics Data System (ADS)

Thorsrud, Mikjel

2018-05-01

We present a complete list of general relativistic shear-free solutions in a class of anisotropic, spatially homogeneous and orthogonal cosmological models containing a collection of n independent p-form gauge fields, where p\\in\\{0, 1, 2, 3\\} , in addition to standard ΛCDM matter fields modelled as perfect fluids. Here a (collection of) gauge field(s) balances anisotropic spatial curvature on the right-hand side of the shear propagation equation. The result is a class of solutions dynamically equivalent to standard FLRW cosmologies, with an effective curvature constant Keff that depends both on spatial curvature and the energy density of the gauge field(s). In the case of a single gauge field (n  =  1) we show that the only spacetimes that admit such solutions are the LRS Bianchi type III, Bianchi type VI0 and Kantowski–Sachs metric, which are dynamically equivalent to open (Keff<0 ), flat (Keff=0 ) and closed (Keff>0 ) FLRW models, respectively. With a collection of gauge fields (n  >  1) also Bianchi type II admits a shear-free solution (Keff>0 ). We identify the LRS Bianchi type III solution to be the unique shear-free solution with a gauge field Hamiltonian bounded from below in the entire class of models.

Maladaptive spinal plasticity opposes spinal learning and recovery in spinal cord injury

PubMed Central

Ferguson, Adam R.; Huie, J. Russell; Crown, Eric D.; Baumbauer, Kyle M.; Hook, Michelle A.; Garraway, Sandra M.; Lee, Kuan H.; Hoy, Kevin C.; Grau, James W.

2012-01-01

Synaptic plasticity within the spinal cord has great potential to facilitate recovery of function after spinal cord injury (SCI). Spinal plasticity can be induced in an activity-dependent manner even without input from the brain after complete SCI. A mechanistic basis for these effects is provided by research demonstrating that spinal synapses have many of the same plasticity mechanisms that are known to underlie learning and memory in the brain. In addition, the lumbar spinal cord can sustain several forms of learning and memory, including limb-position training. However, not all spinal plasticity promotes recovery of function. Central sensitization of nociceptive (pain) pathways in the spinal cord may emerge in response to various noxious inputs, demonstrating that plasticity within the spinal cord may contribute to maladaptive pain states. In this review we discuss interactions between adaptive and maladaptive forms of activity-dependent plasticity in the spinal cord below the level of SCI. The literature demonstrates that activity-dependent plasticity within the spinal cord must be carefully tuned to promote adaptive spinal training. Prior work from our group has shown that stimulation that is delivered in a limb position-dependent manner or on a fixed interval can induce adaptive plasticity that promotes future spinal cord learning and reduces nociceptive hyper-reactivity. On the other hand, stimulation that is delivered in an unsynchronized fashion, such as randomized electrical stimulation or peripheral skin injuries, can generate maladaptive spinal plasticity that undermines future spinal cord learning, reduces recovery of locomotor function, and promotes nociceptive hyper-reactivity after SCI. We review these basic phenomena, how these findings relate to the broader spinal plasticity literature, discuss the cellular and molecular mechanisms, and finally discuss implications of these and other findings for improved rehabilitative therapies after SCI. PMID

Curvature-processing network in macaque visual cortex

PubMed Central

Yue, Xiaomin; Pourladian, Irene S.; Tootell, Roger B. H.; Ungerleider, Leslie G.

2014-01-01

Our visual environment abounds with curved features. Thus, the goal of understanding visual processing should include the processing of curved features. Using functional magnetic resonance imaging in behaving monkeys, we demonstrated a network of cortical areas selective for the processing of curved features. This network includes three distinct hierarchically organized regions within the ventral visual pathway: a posterior curvature-biased patch (PCP) located in the near-foveal representation of dorsal V4, a middle curvature-biased patch (MCP) located on the ventral lip of the posterior superior temporal sulcus (STS) in area TEO, and an anterior curvature-biased patch (ACP) located just below the STS in anterior area TE. Our results further indicate that the processing of curvature becomes increasingly complex from PCP to ACP. The proximity of the curvature-processing network to the well-known face-processing network suggests a possible functional link between them. PMID:25092328

Progressive Spinal Kyphosis in the Aging Population.

PubMed

Ailon, Tamir; Shaffrey, Christopher I; Lenke, Lawrence G; Harrop, James S; Smith, Justin S

2015-10-01

Thoracic kyphosis tends to increase with age. Hyperkyphosis is defined as excessive curvature of the thoracic spine and may be associated with adverse health effects. Hyperkyphosis in isolation or as a component of degenerative kyphoscoliosis has important implications for the surgical management of adult spinal deformity. Our objective was to review the literature on the epidemiology, etiology, natural history, management, and outcomes of thoracic hyperkyphosis. We performed a narrative review of literature on thoracic hyperkyphosis and its implications for adult spinal deformity surgery. Hyperkyphosis has a prevalence of 20% to 40% and is more common in the geriatric population. The cause is multifactorial and involves an interaction between degenerative changes, vertebral compression fractures, muscular weakness, and altered biomechanics. It may be associated with adverse health consequences including impaired physical function, pain and disability, impaired pulmonary function, and increased mortality. Nonoperative management may slow the progression of kyphosis and improve function. Surgery is rarely performed for isolated hyperkyphosis in the elderly due to the associated risk, but is an option when kyphosis occurs in the context of significant deformity. In this scenario, increased thoracic kyphosis influences selection of fusion levels and overall surgical planning. Kyphosis is common in older individuals and is associated with adverse health effects and increased mortality. Current evidence suggests a role for nonoperative therapies in reducing kyphosis and delaying its progression. Isolated hyperkyphosis in the elderly is rarely treated surgically; however, increased thoracic kyphosis as a component of global spinal deformity has important implications for patient selection and operative planning.

Radius of curvature measurement of spherical smooth surfaces by multiple-beam interferometry in reflection

NASA Astrophysics Data System (ADS)

Abdelsalam, D. G.; Shaalan, M. S.; Eloker, M. M.; Kim, Daesuk

2010-06-01

In this paper a method is presented to accurately measure the radius of curvature of different types of curved surfaces of different radii of curvatures of 38 000,18 000 and 8000 mm using multiple-beam interference fringes in reflection. The images captured by the digital detector were corrected by flat fielding method. The corrected images were analyzed and the form of the surfaces was obtained. A 3D profile for the three types of surfaces was obtained using Zernike polynomial fitting. Some sources of uncertainty in measurement were calculated by means of ray tracing simulations and the uncertainty budget was estimated within λ/40.

Posture-related distribution of hyperbaric bupivacaine in cerebro-spinal fluid is influenced by spinal needle characteristics.

PubMed

Mardirosoff, C; Dumont, L; Deyaert, M; Leconte, M

2001-07-01

No studies have evaluated the relationship between duration of time sitting and spinal needle type on the maximal spread of local anaesthetics. The few trials available have studied the influence of time spent sitting on the spread of anaesthesia without standardising spinal needle types, and have not found any effect. In this randomised, blinded study, 60 patients scheduled for elective orthopaedic surgery of the lower limbs were divided into 4 groups. With the patient sitting erect, 15 mg hyperbaric bupivacaine were injected in a standard manner through a 24G Sprotte or a 27G Whitacre needle and patients were placed supine after 1 min (24G/1 group and 27G/1 group) or 4 min (24G/4 group and 27G/4 group). Time to achieve maximum block height after injection was similar in all groups. Block height levels were significantly lower at all time points for the 24G/4 group. Maximum block heights were Th4 in the 24G/1, 27G/1 and 27G/4 groups, and Th6 in the 24G/4 group (P<0.0001). In a standard spinal anaesthesia procedure, when different lengths of time spent sitting are compared, spinal needle characteristics influence the maximum spread of hyperbaric bupivacaine. However, within the limits of our study, a two-segment difference in block height is too small to consider using spinal needles as valuable tools to control block height during spinal anaesthesia in our daily practice.

Curvature of the localized surface plasmon resonance peak.

PubMed

Chen, Peng; Liedberg, Bo

2014-08-05

Localized surface plasmon resonance (LSPR) occurring in noble metal nanoparticles (e.g., Au) is a widely used phenomenon to report molecular interactions. Traditional LSPR sensors typically monitor shifts in the peak position or extinction in response to local refractive index changes in the close vicinity of the nanoparticle surface. The ability to resolve minute shifts/extinction changes is to a large extent limited by instrumental noise. A new strategy to evaluate LSPR responses utilizing changes in the shape of the extinction spectrum (the curvature) is proposed. The response of curvature to refractive index changes is investigated theoretically using Mie theory and an analytical expression relating the curvature to the refractive index is presented. The experimentally derived curvatures for 13 nm spherical gold nanoparticles (AuNPs) exposed to solvents with different bulk refractive indices confirm the theoretical predictions. Moreover, both the calculated and experimental findings suggest that the curvature is approximately a linear function of refractive index in regimes relevant to bio and chemical sensing. We demonstrate that curvature is superior over peak shift and extinction both in terms of signal-to-noise (S/N) ratio and reliability of LSPR sensors. With a curvature, one could readily monitor submonolayer adsorption of a low molecular weight thiol molecule (M(w) = 458.6) onto 13 nm AuNPs. It is also worthwhile mentioning that curvature is virtually insensitive to instrumental instabilities and artifacts occurring during measurement. Instabilities such as baseline tilt and shift, shift in peak position as well as sharp spikes/steps in the extinction spectra do not induce artifacts in the sensorgrams of curvature.

Curvature-Mediated Assembly of Janus Nanoparticles on Membrane Vesicles.

PubMed

Bahrami, Amir Houshang; Weikl, Thomas R

2018-02-14

Besides direct particle-particle interactions, nanoparticles adsorbed to biomembranes experience indirect interactions that are mediated by the membrane curvature arising from particle adsorption. In this Letter, we show that the curvature-mediated interactions of adsorbed Janus particles depend on the initial curvature of the membrane prior to adsorption, that is, on whether the membrane initially bulges toward or away from the particles in our simulations. The curvature-mediated interaction can be strongly attractive for Janus particles adsorbed to the outside of a membrane vesicle, which initially bulges away from the particles. For Janus particles adsorbed to the vesicle inside, in contrast, the curvature-mediated interactions are repulsive. We find that the area fraction of the adhesive Janus particle surface is an important control parameter for the curvature-mediated interaction and assembly of the particles, besides the initial membrane curvature.

Radius of Curvature of Off-Axis Paraboloids

NASA Technical Reports Server (NTRS)

Robinson, Brian; Reardon, Patrick; Hadaway, James; Geary, Joseph; Russell, Kevin (Technical Monitor)

2002-01-01

We present several methods for measuring the vertex radius of curvature of off-axis paraboloidal mirrors. One is based on least-squares fitting of interferometer output, one on comparison of sagittal and tangential radii of curvature, and another on measurement of displacement of the nulled test article from the ideal reference wave. Each method defines radius of curvature differently and, as a consequence, produces its own sort of errors.

Spinal Cord Injury in the Geriatric Population: Risk Factors, Treatment Options, and Long-Term Management.

PubMed

Ikpeze, Tochukwu C; Mesfin, Addisu

2017-06-01

Spinal cord injuries (SCIs) are sustained by more than 12 500 patients per year in the United States and more globally. The SCIs disproportionately affect the elderly, especially men. Approximately 60% of these injuries are sustained traumatically through falls, but nontraumatic causes including infections, tumors, and medication-related epidural bleeding have also been documented. Preexisting conditions such as ankylosing spondylitis and diffuse idiopathic skeletal hyperostosis can render the spine stiff and are risk factors as well as cervical spondylosis and ensuing cervical stenosis. Treatment options vary depending on the severity, location, and complexity of the injury. Surgical management has been growing in popularity over the years and remains an option as it helps reduce spinal cord compression and alleviate pain. Elevating mean arterial pressures to prevent spinal cord ischemia and avoiding the second hit of SCI have become more common as opposed to high dose steroids. Ongoing clinical trials with pharmacological agents such as minocycline and riluzole have shown early, promising results in their ability to reduce cellular damage and facilitate recovery. Though SCI can be life changing, the available treatment options have aimed to reduce pain and minimize complications and maintain quality of life alongside rehabilitative services.

Antimicrobial prophylaxis to prevent surgical site infection in adolescent idiopathic scoliosis patients undergoing posterior spinal fusion: 2 doses versus antibiotics till drain removal.

PubMed

Kamath, Vijay H D; Cheung, Jason Pui Yin; Mak, Kin Cheung; Wong, Yat Wa; Cheung, Wai Yuen; Luk, Keith Dip Kei; Cheung, Kenneth Man Chee

2016-10-01

There is much variation in the choice, timing and duration of antimicrobial prophylaxis for preventing surgical site infections (SSI) but no guideline exists for scoliosis surgery. The aim of study was to compare the efficacy of two antimicrobial prophylaxis (AMP) protocols with cephazolin in preventing SSI in adolescent idiopathic scoliosis (AIS). A retrospective comparative analysis of two post-operative AMP protocols (two postoperative doses versus continued antibiotics till drain removal) was performed. Patient characteristics, pre-operative, intra- and post-operative risk factors for infection, drain use, generic drug name and number of doses administered were recorded from 226 patients with AIS who had undergone posterior spinal fusion. Details of superficial or deep SSI and wound healing aberrations, and serious adverse events were recorded. Analysis was performed to evaluate differences in the pre-, intra- and post-operative variables between the two groups. 155 patients received 2 postoperative doses of AMP and 71 patients had antibiotics till drain removal. The average follow-up was 43 months. The overall rate of SSI was 1.7 % for the spine wound and 1.3 % for the iliac crest wound. 1.9 % of patients with 2 doses of AMP and 1.4 % of patients with antibiotics till drain removal had SSI. No adverse reactions attributable to cephazolin were observed. This is the first study on the AMP protocol in scoliosis surgery for SSI prevention. Results suggest that two doses of AMP are as effective as continued antimicrobial use until drain removal. Cephazolin appears to be effective and safe for prophylaxis.

Long-time behavior of material-surface curvature in isotropic turbulence

NASA Technical Reports Server (NTRS)

Girimaji, S. S.

1992-01-01

The behavior at large times of the curvature of material elements in turbulence is investigated using Lagrangian velocity-gradient time series obtained from direct numerical simulations of isotropic turbulence. The main objectives are: to study the asymptotic behavior of the pdf curvature as a function of initial curvature and shape; and to establish whether the curvature of an initially plane material element goes to a stationary probability distribution. The evidence available in the literature about the asymptotic curvature-pdf of initially flat surfaces is ambiguous, and the conjecture is that it is quasi-stationary. In this work several material-element ensembles of different initial curvatures and shapes are studied. It is found that, at long times the moments of the logarithm of curvature are independent of the initial pdf of curvature. This, it is argued, supports the view that the curvature attains a stationary distribution at long times. It is also shown that, irrespective of initial shape or curvature, the shape of any material element at long times is cylindrical with a high probability.

Turbulent boundary layers subjected to multiple curvatures and pressure gradients

NASA Technical Reports Server (NTRS)

Bandyopadhyay, Promode R.; Ahmed, Anwar

1993-01-01

The effects of abruptly applied cycles of curvatures and pressure gradients on turbulent boundary layers are examined experimentally. Two two-dimensional curved test surfaces are considered: one has a sequence of concave and convex longitudinal surface curvatures and the other has a sequence of convex and concave curvatures. The choice of the curvature sequences were motivated by a desire to study the asymmetric response of turbulent boundary layers to convex and concave curvatures. The relaxation of a boundary layer from the effects of these two opposite sequences has been compared. The effect of the accompaying sequences of pressure gradient has also been examined but the effect of curvature dominates. The growth of internal layers at the curvature junctions have been studied. Measurements of the Gortler and corner vortex systems have been made. The boundary layer recovering from the sequence of concave to convex curvature has a sustained lower skin friction level than in that recovering from the sequence of convex to concave curvature. The amplification and suppression of turbulence due to the curvature sequences have also been studied.

Effect of Surgical Approach on Pulmonary Function in Adolescent Idiopathic Scoliosis Patients: A Systemic Review and Meta-analysis.

PubMed

Lee, Andy C H; Feger, Mark A; Singla, Anuj; Abel, Mark F

2016-11-15

Systemic review and meta-analysis. To analyze the effect of spinal fusion and instrumentation for adolescent idiopathic scoliosis (AIS) on absolute pulmonary function test (PFTs). Pulmonary function is correlated with severity of deformity in AIS patients and studies that have analyzed the effect of spinal fusion and instrumentation on PFTs for AIS have reported inconsistent results. There is a need to analyze the effect of spinal fusion on PFTs with stratification by surgical approach. Our analysis included 22 studies. Cohen's d effect sizes were calculated for absolute PFT outcome measures with 95% confidence intervals (CI). Meta-analyses were performed at each postoperative time frame for six homogeneous surgical approaches: (i) combined anterior release and posterior fusion with instrumentation; (ii) combined video assisted anterior release and posterior fusion with instrumentation without thoracoplasty; (iii) posterior fusion with instrumentation without thoracoplasty; (iv) anterior fusion with instrumentation and without thoracoplasty; (v) video assisted anterior fusion with instrumentation without thoracoplasty; and (vi) any scoliosis surgery with additional thoracoplasty. Anterior spinal fusion with instrumentation, any scoliosis surgery with concomitant thoracoplasty, or video-assisted anterior fusion with instrumentation for AIS had similar absolute PFTs at their 2 year postoperative follow up compared with their preoperative PFTs (effect sizes ranging from -0.2-0.2 with all CI crossing "0"). Posterior spinal fusion with instrumentation (with or without an anterior release) demonstrated small to moderate increases in PFTs 2 years postoperatively (effect sizes ranging from 0.35-0.65 with all CI not crossing "0"). Anterior fusion with instrumentation, regardless of the approach, and any scoliosis surgery with concomitant thoracoplasty do not lead to significant change in pulmonary functions 2 year after surgery. Posterior spinal fusion with instrumentation

French consensus. Idiopathic hypersomnia: Investigations and follow-up.

PubMed

Leu-Semenescu, S; Quera-Salva, M-A; Dauvilliers, Y

Idiopathic hypersomnia is a rare, central hypersomnia, recently identified and to date of unknown physiopathology. It is characterised by a more or less permanent, excessive daytime sleepiness, associated with long and unrefreshing naps. Night-time sleep is of good quality, excessive in quantity, associated with sleep inertia in the subtype previously described as "with long sleep time". Diagnosis of idiopathic hypersomnia is complex due to the absence of a quantifiable biomarker, the heterogeneous symptoms, which overlap with the clinical picture of type 2 narcolepsy, and its variable evolution over time. Detailed evaluation enables other frequent causes of somnolence, such as depression or sleep deprivation, to be eliminated. Polysomnography and multiple sleep latency tests (MSLT) are essential to rule out other sleep pathologies and to objectify excessive daytime sleepiness. Sometimes the MSLT do not show excessive sleepiness, hence a continued sleep recording of at least 24hours is necessary to show prolonged sleep (>11h/24h). In this article, we propose recommendations for the work-up to be carried out during diagnosis and follow-up for patients suffering from idiopathic hypersomnia. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Involvement of peripheral and spinal tumor necrosis factor α in spinal cord hyperexcitability during knee joint inflammation in rats.

PubMed

König, Christian; Zharsky, Maxim; Möller, Christian; Schaible, Hans-Georg; Ebersberger, Andrea

2014-03-01

Tumor necrosis factor α (TNFα) is produced not only in peripheral tissues, but also in the spinal cord. The purpose of this study was to address the potential of peripheral and spinal TNFα to induce and maintain spinal hyperexcitability, which is a hallmark of pain states in the joints during rheumatoid arthritis and osteoarthritis. In vivo recordings of the responses of spinal cord neurons to nociceptive knee input under normal conditions and in the presence of experimental knee joint inflammation were obtained in anesthetized rats. TNFα, etanercept, or antibodies to TNF receptors were applied to either the knee joint or the spinal cord surface. Injection of TNFα into the knee joint cavity increased the responses of spinal cord neurons to mechanical joint stimulation, and injection of etanercept into the knee joint reduced the inflammation-evoked spinal activity. These spinal effects closely mirrored the induction and reduction of peripheral sensitization. Responses to joint stimulation were also enhanced by spinal application of TNFα, and spinal application of either etanercept or anti-TNF receptor type I significantly attenuated the generation of inflammation-evoked spinal hyperexcitability, which is characterized by widespread pain sensitization beyond the inflamed joint. Spinally applied etanercept did not reduce established hyperexcitability in the acute kaolin/carrageenan model. In antigen-induced arthritis, etanercept decreased spinal responses on day 1, but not on day 3. While peripheral TNFα increases spinal responses to joint stimulation, spinal TNFα supports the generation of the full pattern of spinal hyperexcitability. However, established spinal hyperexcitability may be maintained by downstream mechanisms that are independent of spinal TNFα. Copyright © 2014 by the American College of Rheumatology.

The development of curvature in the porcine radioulna

PubMed Central

Pantinople, Jess; McCabe, Kyle; Henderson, Keith; Milne, Nick

2017-01-01

Long bone curvature in animal limbs has long been a subject of interest and much work has explored why long bones should be curved. However, the ‘when’ and ‘how’ of curvature development is poorly understood. It has been shown that the rat tibia fails to attain its normal curvature if the action of muscles is removed early in life, but it is not clear if this is because the curvature fails to develop or if the bone becomes straighter without the action of muscles. No studies have examined the development of bone curvature in a normally developing quadruped, so this study tracks the course of curvature formation in the radioulna in a series of growing pigs. We also histologically examined the epiphyseal growth plates of these bones to determine if they contribute to the formation of curvature. In all three epiphyseal plates examined, the proliferative zone is thicker and more densely populated with chondrocytes on the cranial (convex) side than the caudal (concave) side. Frost’s chondral modelling theory would suggest that the cranial side of the bone is under more compression than the caudal side, and we conclude that this is due to the action of triceps extending the elbow by pulling on the olecranon process. These results support the idea that bone curvature is an adaptation to habitual loading, where longitudinal loads acting on the curved bone cause bending strains that counter the bending resulting from the habitual muscle action. PMID:28584714

The development of curvature in the porcine radioulna.

PubMed

Pantinople, Jess; McCabe, Kyle; Henderson, Keith; Richards, Hazel L; Milne, Nick

2017-01-01

Long bone curvature in animal limbs has long been a subject of interest and much work has explored why long bones should be curved. However, the 'when' and 'how' of curvature development is poorly understood. It has been shown that the rat tibia fails to attain its normal curvature if the action of muscles is removed early in life, but it is not clear if this is because the curvature fails to develop or if the bone becomes straighter without the action of muscles. No studies have examined the development of bone curvature in a normally developing quadruped, so this study tracks the course of curvature formation in the radioulna in a series of growing pigs. We also histologically examined the epiphyseal growth plates of these bones to determine if they contribute to the formation of curvature. In all three epiphyseal plates examined, the proliferative zone is thicker and more densely populated with chondrocytes on the cranial (convex) side than the caudal (concave) side. Frost's chondral modelling theory would suggest that the cranial side of the bone is under more compression than the caudal side, and we conclude that this is due to the action of triceps extending the elbow by pulling on the olecranon process. These results support the idea that bone curvature is an adaptation to habitual loading, where longitudinal loads acting on the curved bone cause bending strains that counter the bending resulting from the habitual muscle action.

New derivation of the wavefront curvature transformation at an interface between two inhomogeneous media

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

Uzsin, B.

The principles for ray-tracing and wavefront curvature calculations in a three-dimensional medium are reviewed. A new derivation of the transformation of the wavefront curvature matrix at an interface between two inhomogeneous media is given. The derivation is based on a Taylor series expansion of the ray refraction equation at the interface between two inhomogeneous media, and only elementary geometric arguments are used. The wavefront curvature transformation at the interface is obtained by neglecting all terms in the direction of the surface normal. With proper definition of the variables, the derivation is also valid for a reflected wavefront. A simplified transformationmore » rule is derived for a reflected wave of the same type as the incident wave.« less

In vivo distribution of spinal intervertebral stiffness based on clinical flexibility tests.

PubMed

Lafon, Yoann; Lafage, Virginie; Steib, Jean-Paul; Dubousset, Jean; Skalli, Wafa

2010-01-15

A numerical study was conducted to identify the intervertebral stiffness of scoliotic spines from spinal flexibility tests. To study the intervertebral 3-dimensional (3D) stiffness distribution along scoliotic spine. Few methods have been reported in literature to quantify the in vivo 3D intervertebral stiffness of the scoliotic spine. Based on the simulation of flexibility tests, these methods were operator-dependent and could yield to clinically irrelevant stiffnesses. This study included 30 patients surgically treated for severe idiopathic scoliosis. A previously validated trunk model, with patient-specific geometry, was used to simulate bending tests according to the in vivo displacements of T1 and L5 measured from bending test radiographs. Differences between in vivo and virtual spinal behaviors during bending tests (left and right) were computed in terms of vertebral rotations and translation. An automated method, driven by a priori knowledge, identified intervertebral stiffnesses in order to reproduce the in vivo spinal behavior. Because of the identification of intervertebral stiffnesses, differences between in vivo and virtual spinal displacements were drastically reduced (95% of the differences less than +/-3 mm for vertebral translation). Intervertebral stiffness distribution after identification was analyzed. On convex side test, the intervertebral stiffness of the compensatory curves increased in most cases, whereas the major curve became more flexible. Stiffness singularities were found in junctional zones: these specific levels were predominantly flexible, both in torsion and in lateral bending. The identification of in vivo intervertebral stiffness may improve our understanding of scoliotic spine and the relevance of patient-specific methods for surgical planning.

Intrinsic DNA curvature in trypanosomes.

PubMed

Smircich, Pablo; El-Sayed, Najib M; Garat, Beatriz

2017-11-09

Trypanosoma cruzi and Trypanosoma brucei are protozoan parasites causing Chagas disease and African sleeping sickness, displaying unique features of cellular and molecular biology. Remarkably, no canonical signals for RNA polymerase II promoters, which drive protein coding genes transcription, have been identified so far. The secondary structure of DNA has long been recognized as a signal in biological processes and more recently, its involvement in transcription initiation in Leishmania was proposed. In order to study whether this feature is conserved in trypanosomatids, we undertook a genome wide search for intrinsic DNA curvature in T. cruzi and T. brucei. Using a region integrated intrinsic curvature (RIIC) scoring that we previously developed, a non-random distribution of sequence-dependent curvature was observed. High RIIC scores were found to be significantly correlated with transcription start sites in T. cruzi, which have been mapped in divergent switch regions, whereas in T. brucei, the high RIIC scores correlated with sites that have been involved not only in RNA polymerase II initiation but also in termination. In addition, we observed regions with high RIIC score presenting in-phase tracts of Adenines, in the subtelomeric regions of the T. brucei chromosomes that harbor the variable surface glycoproteins genes. In both T. cruzi and T. brucei genomes, a link between DNA conformational signals and gene expression was found. High sequence dependent curvature is associated with transcriptional regulation regions. High intrinsic curvature also occurs at the T. brucei chromosome subtelomeric regions where the recombination processes involved in the evasion of the immune host system take place. These findings underscore the relevance of indirect DNA readout in these ancient eukaryotes.

Effects of Iris Surface Curvature on Iris Recognition

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

Thompson, Joseph T; Flynn, Patrick J; Bowyer, Kevin W

To focus on objects at various distances, the lens of the eye must change shape to adjust its refractive power. This change in lens shape causes a change in the shape of the iris surface which can be measured by examining the curvature of the iris. This work isolates the variable of iris curvature in the recognition process and shows that differences in iris curvature degrade matching ability. To our knowledge, no other work has examined the effects of varying iris curvature on matching ability. To examine this degradation, we conduct a matching experiment across pairs of images with varyingmore » degrees of iris curvature differences. The results show a statistically signi cant degradation in matching ability. Finally, the real world impact of these ndings is discussed« less

Further consideration of the curvature of the Neandertal Femur.

PubMed

Chapman, Tara; Sholukha, Victor; Semal, Patrick; Louryan, Stéphane; Van Sint Jan, Serge

2018-01-01

Neandertal femora are particularly known for having a marked sagittal femoral curvature. This study examined femoral curvature in Neandertals in comparison to a modern human population from Belgium by the use of three-dimensional (3D) quadric surfaces modeled from the bone surface. 3D models provide detailed information and enabled femoral curvature to be analyzed in conjunction with other morphological parameters. 3D models were created from CT scans of 75 modern human femora and 7 Neandertal femora. Quadric surfaces (QS) were created from the triangulated surface vertices in all areas of interest (neck, head, diaphyseal shaft, condyles) extracted from previously placed anatomical landmarks. The diaphyseal shaft was divided into five QS shapes and curvature was measured by degrees of difference between QS shapes. Each bone was placed in a local coordinate system enabling each bone to be analyzed in the same way. The use of 3D quadric surface fitting allowed the distribution of curvature with similarly curved femora to be analyzed and the different patterns of curvature between the two groups to be determined. The Neandertals were shown to have a higher degree of femoral curvature and a more distal point of femoral curvature than the modern human population from Belgium. Morphological aspects of the Neandertal femur are different from this modern human population although mainly seem unrelated to femoral curvature. The relative lack of correlations with other femoral bony morphological factors suggests femoral curvature variations may be related to other aspects. © 2017 Wiley Periodicals, Inc.

Curvature Constraints from the Causal Entropic Principle

NASA Astrophysics Data System (ADS)

Bozek, Brandon

2010-01-01

Current cosmological observations indicate a preference for a cosmological constant that is drastically smaller than what can be explained by conventional particle physics. The Causal Entropic Principle (Bousso, et al.) provides an alternative approach to anthropic attempts to predict our observed value of the cosmological constant by calculating the entropy created within a causal diamond. We have extended this work to use the Causal Entropic Principle to predict the preferred curvature within the "multiverse." We have found that values larger than ρk = 40*ρm are disfavored by more than 99.99% and a peak value at ρΛ = 7.9*10-123 and ρk =4.3*ρm for open universes. For universes that allow only positive curvature or both positive and negative curvature, we find a correlation between curvature and dark energy that leads to an extended region of preferred values. Our universe is found to be disfavored to an extent depending on the priors on curvature. We also provide a comparison to previous anthropic constraints on open universes and discuss future directions for this work.

Curvature constraints from the causal entropic principle

NASA Astrophysics Data System (ADS)

Bozek, Brandon; Albrecht, Andreas; Phillips, Daniel

2009-07-01

Current cosmological observations indicate a preference for a cosmological constant that is drastically smaller than what can be explained by conventional particle physics. The causal entropic principle (Bousso et al.) provides an alternative approach to anthropic attempts to predict our observed value of the cosmological constant by calculating the entropy created within a causal diamond. We have extended this work to use the causal entropic principle to predict the preferred curvature within the “multiverse.” We have found that values larger than ρk=40ρm are disfavored by more than 99.99% peak value at ρΛ=7.9×10-123 and ρk=4.3ρm for open universes. For universes that allow only positive curvature or both positive and negative curvature, we find a correlation between curvature and dark energy that leads to an extended region of preferred values. Our universe is found to be disfavored to an extent depending on the priors on curvature. We also provide a comparison to previous anthropic constraints on open universes and discuss future directions for this work.

Natural history of idiopathic diabetes insipidus.

PubMed

Richards, Gail E; Thomsett, Michael J; Boston, Bruce A; DiMeglio, Linda A; Shulman, Dorothy I; Draznin, Martin

2011-10-01

To determine what percentage of diabetes insipidus (DI) in childhood is idiopathic and to assess the natural history of idiopathic DI. We conducted a retrospective chart review of 105 patients with DI who were born or had DI diagnosed between 1980-1989 at 3 medical centers. A second cohort of 30 patients from 6 medical centers in whom idiopathic DI was diagnosed after 1990 was evaluated retrospectively for subsequent etiologic diagnoses and additional hypothalamic/pituitary deficiencies and prospectively for quality of life. In the first cohort, 11% of patients had idiopathic DI. In the second cohort, additional hypothalamic/pituitary hormone deficiencies developed in 33%, and 37% received an etiologic diagnosis for DI. Health-related quality of life for all the patients with idiopathic DI was comparable with the healthy reference population. Only a small percentage of patients with DI will remain idiopathic after first examination. Other hormone deficiencies will develop later in one-third of those patients, and slightly more than one-third of those patients will have an etiology for the DI diagnosed. Long-term surveillance is important because tumors have been diagnosed as long as 21 years after the onset of DI. Quality of life for these patients is as good as the reference population. Copyright © 2011 Mosby, Inc. All rights reserved.

Determinants of Curvature-Sensing Behavior for MARCKS-Fragment Peptides.

PubMed

de Jesus, Armando J; White, Ormacinda R; Flynn, Aaron D; Yin, Hang

2016-05-10

It is increasingly recognized that membrane curvature plays an important role in various cellular activities such as signaling and trafficking, as well as key issues involving health and disease development. Thus, curvature-sensing peptides are essential to the study and detection of highly curved bilayer structures. The effector domain of myristoylated alanine-rich C-kinase substrate (MARCKS-ED) has been demonstrated to have curvature-sensing ability. Research of the MARCKS-ED has further revealed that its Lys and Phe residues play an essential role in how MARCKS-ED detects and binds to curved bilayers. MARCKS-ED has the added property of being a lower-molecular-weight curvature sensor, which offers advantages in production. With that in mind, this work investigates peptide-sequence-related factors that influence curvature sensing and explores whether peptide fragments of even shorter length can function as curvature sensors. Using both experimental and computational methods, we studied the curvature-sensing capabilities of seven fragments of MARCKS-ED. Two of the longer fragments were designed from approximately the two halves of the full-length peptide whereas the five shorter fragments were taken from the central stretch of MARCKS-ED. Fully atomistic molecular dynamics simulations show that the fragments that remain bound to the bilayer exhibit interactions with the bilayer similar to that of the full-length MARCKS-ED peptide. Fluorescence enhancement and anisotropy assays, meanwhile, reveal that five of the MARCKS fragments possess the ability to sense membrane curvature. Based on the sequences of the curvature-sensing fragments, it appears that the ability to sense curvature involves a balance between the numbers of positively charged residues and hydrophobic anchoring residues. Together, these findings help crystallize our understanding of the molecular mechanisms underpinning the curvature-sensing behaviors of peptides, which will prove useful in the

Nanoscale Membrane Curvature detected by Polarized Localization Microscopy

NASA Astrophysics Data System (ADS)

Kelly, Christopher; Maarouf, Abir; Woodward, Xinxin

Nanoscale membrane curvature is a necessary component of countless cellular processes. Here we present Polarized Localization Microscopy (PLM), a super-resolution optical imaging technique that enables the detection of nanoscale membrane curvature with order-of-magnitude improvements over comparable optical techniques. PLM combines the advantages of polarized total internal reflection fluorescence microscopy and fluorescence localization microscopy to reveal single-fluorophore locations and orientations without reducing localization precision by point spread function manipulation. PLM resolved nanoscale membrane curvature of a supported lipid bilayer draped over polystyrene nanoparticles on a glass coverslip, thus creating a model membrane with coexisting flat and curved regions and membrane radii of curvature as small as 20 nm. Further, PLM provides single-molecule trajectories and the aggregation of curvature-inducing proteins with super-resolution to reveal the correlated effects of membrane curvature, dynamics, and molecular sorting. For example, cholera toxin subunit B has been observed to induce nanoscale membrane budding and concentrate at the bud neck. PLM reveals a previously hidden and critical information of membrane topology.

Curvature constraints from large scale structure

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

Dio, Enea Di; Montanari, Francesco; Raccanelli, Alvise

We modified the CLASS code in order to include relativistic galaxy number counts in spatially curved geometries; we present the formalism and study the effect of relativistic corrections on spatial curvature. The new version of the code is now publicly available. Using a Fisher matrix analysis, we investigate how measurements of the spatial curvature parameter Ω {sub K} with future galaxy surveys are affected by relativistic effects, which influence observations of the large scale galaxy distribution. These effects include contributions from cosmic magnification, Doppler terms and terms involving the gravitational potential. As an application, we consider angle and redshift dependentmore » power spectra, which are especially well suited for model independent cosmological constraints. We compute our results for a representative deep, wide and spectroscopic survey, and our results show the impact of relativistic corrections on spatial curvature parameter estimation. We show that constraints on the curvature parameter may be strongly biased if, in particular, cosmic magnification is not included in the analysis. Other relativistic effects turn out to be subdominant in the studied configuration. We analyze how the shift in the estimated best-fit value for the curvature and other cosmological parameters depends on the magnification bias parameter, and find that significant biases are to be expected if this term is not properly considered in the analysis.« less

Space Curvature and the "Heavy Banana 'Paradox.'"

ERIC Educational Resources Information Center

Gruber, Ronald P.; And Others

1991-01-01

Two ways to visually enhance the concept of space curvature are described. Viewing space curvature as a meterstick contraction and the heavy banana "paradox" are discussed. The meterstick contraction is mathematically explained. (KR)

Robust estimation of adaptive tensors of curvature by tensor voting.

PubMed

Tong, Wai-Shun; Tang, Chi-Keung

2005-03-01

Although curvature estimation from a given mesh or regularly sampled point set is a well-studied problem, it is still challenging when the input consists of a cloud of unstructured points corrupted by misalignment error and outlier noise. Such input is ubiquitous in computer vision. In this paper, we propose a three-pass tensor voting algorithm to robustly estimate curvature tensors, from which accurate principal curvatures and directions can be calculated. Our quantitative estimation is an improvement over the previous two-pass algorithm, where only qualitative curvature estimation (sign of Gaussian curvature) is performed. To overcome misalignment errors, our improved method automatically corrects input point locations at subvoxel precision, which also rejects outliers that are uncorrectable. To adapt to different scales locally, we define the RadiusHit of a curvature tensor to quantify estimation accuracy and applicability. Our curvature estimation algorithm has been proven with detailed quantitative experiments, performing better in a variety of standard error metrics (percentage error in curvature magnitudes, absolute angle difference in curvature direction) in the presence of a large amount of misalignment noise.

Significance of peak height velocity as a predictive factor for curve progression in patients with idiopathic scoliosis

PubMed Central

2015-01-01

Background Much attention has been paid to peak height velocity (PHV) as a possible predictor of curve progression in patients with idiopathic scoliosis (IS). The aim of this study was to analyze the relationship between the magnitude of the Cobb angle at PHV and scoliosis progression, defined as having surgery prior to skeletal maturity in female patients with IS. Methods A retrospective review identified 56 skeletally immature female IS patients who were followed until maturity. The mean age and the mean pubertal status at the initial visit were 10 years and 24 months before menarche respectively, with a follow-up period of 5 years. They were divided into two groups: non-surgery group (NS) and surgery group (S), depending on their treatment method in use at the final follow-up visit. Surgery group was defined as an ultimately having surgery due to Cobb angle greater than 45 degrees prior to skeletal maturity regardless of conservative management. Height measurements were recorded at each visit; height velocity was calculated as the height change, in cm, divided by the time interval, in years. The PHV, chronological age at PHV (APHV), height at PHV (HPHV), and final height (FH) were determined for each group. In patients with Cobb angle greater than 30 degrees, the corrected height was calculated by Kono formula and corrected height velocity values were provided. The sensitivity, specificity, and area under the curve (AUC) of the receiver-operating -characteristic (ROC) analysis were calculated to predict spinal curve progression for various Cobb-angle cutoff values at PHV. Results The corrected PHV had a mean value of 8.5 and 8.9 cm/year in the NS-group and S-group, respectively. The APHV was 11.9 and 11 years, the corrected HPHV was 152.9, and 149.3 cm, and the corrected FH was 159.9 and 159.3 cm, respectively. When a Cobb angle of 31.5 degrees was at PHV, ROC analysis revealed 78% sensitivity, 82% specificity, and an AUC of 0.93, acceptable values for curve

Vitamin D deficiency in chronic idiopathic urticaria.

PubMed

Movahedi, Masoud; Tavakol, Marzieh; Hirbod-Mobarakeh, Armin; Gharagozlou, Mohammad; Aghamohammadi, Asghar; Tavakol, Zahra; Momenzadeh, Kaveh; Nabavi, Mohammad; Dabbaghzade, Abbas; Mosallanejad, Asieh; Rezaei, Nima

2015-04-01

Chronic urticaria is the most common skin diseases, characterized by chronic cutaneous lesions which severely debilitates patients in several aspects of their everyday life. Vitamin D is known to exert several actions in the immune system and to influence function and differentiation of mast cells, central role players in the pathogenesis of chronic idiopathic urticaria. This study was performed to evaluate the relationship between vitamin D levels and susceptibility to chronic idiopathic urticaria. One hundred and fourteen patients with chronic idiopathic urticaria were recruited in this study along with one hundred and eighty seven sex-matched and age-matched healthy volunteers as the control group. For each patient, urticaria activity score was calculated and autologous serum skin test was done. Vitamin D metabolic statue was measured in serum as 25 hydroxyvitamin D using enzyme immunoassay method. Patients with chronic idiopathic urticaria significantly showed lower levels of vitamin D. Vitamin D deficiency was significantly associated with increased susceptibility to chronic idiopathic urticaria. There was a significant positive correlation between vitamin D levels and urticaria activity score. This study showed that patients with chronic idiopathic urticaria had reduced levels of vitamin D, while vitamin D deficiency could increase susceptibility to chronic idiopathic urticaria.

Spinal blockage of P/Q- or N-type voltage-gated calcium channels modulates functional and symptomatic changes related to haemorrhagic cystitis in mice

PubMed Central

Silva, R B M; Sperotto, N D M; Andrade, E L; Pereira, T C B; Leite, C E; de Souza, A H; Bogo, M R; Morrone, F B; Gomez, M V; Campos, M M

2015-01-01

Background and Purpose Spinal voltage-gated calcium channels (VGCCs) are pivotal regulators of painful and inflammatory alterations, representing attractive therapeutic targets. We examined the effects of epidural administration of the P/Q- and N-type VGCC blockers Tx3-3 and Phα1β, respectively, isolated from the spider Phoneutria nigriventer, on symptomatic, inflammatory and functional changes allied to mouse cyclophosphamide (CPA)-induced haemorrhagic cystitis (HC). The effects of P. nigriventer-derived toxins were compared with those displayed by MVIIC and MVIIA, extracted from the cone snail Conus magus. Experimental Approach HC was induced by a single i.p. injection of CPA (300 mg·kg–1). Dose- and time-related effects of spinally administered P/Q and N-type VGCC blockers were assessed on nociceptive behaviour and macroscopic inflammation elicited by CPA. The effects of toxins were also evaluated on cell migration, cytokine production, oxidative stress, functional cystometry alterations and TRPV1, TRPA1 and NK1 receptor mRNA expression. Key Results The spinal blockage of P/Q-type VGCC by Tx3-3 and MVIIC or N-type VGCC by Phα1β attenuated nociceptive and inflammatory events associated with HC, including bladder oxidative stress and cytokine production. CPA produced a slight increase in bladder TRPV1 and TRPA1 mRNA expression, which was reversed by all the toxins tested. Noteworthy, Phα1β strongly prevented bladder neutrophil migration, besides HC-related functional alterations, and its effects were potentiated by co-injecting the selective NK1 receptor antagonist CP-96345. Conclusions and Implications Our results shed new light on the role of spinal P/Q and N-type VGCC in bladder dysfunctions, pointing out Phα1β as a promising alternative for treating complications associated with CPA-induced HC. PMID:25298144

The impact of direct vertebral rotation (DVR) on radiographic outcome in surgical correction of idiopathic scoliosis.

PubMed

Urbanski, Wiktor; Wolanczyk, Michal J; Jurasz, Wojciech; Kulej, Miroslaw; Morasiewicz, Piotr; Dragan, Szymon Lukasz; Sasiadek, Marek; Dragan, Szymon Feliks

2017-07-01

Recent developments of spinal instruments allow to address nearly all components of idiopathic scoliosis. Direct vertebral rotation (DVR) maneuver was introduced to correct apical axial vertebral rotation. It is however still not well established how efficiently DVR affects results of scoliosis correction. The object of the study was to evaluate en bloc apical vertebral rotation (DVR) and its impact on coronal and sagittal correction of the spine in patients undergoing surgical scoliosis treatment. Thirty-six consecutive patients who underwent posterior spinal fusion with pedicle screws only constructs for idiopathic scoliosis. Fifteen patients (20 curves) were corrected by rod derotation only and 21 patients (26 curves) had both rod derotation and DVR. Curve measurements were performed on x-rays obtained before and postoperatively-coronal curves, kyphosis (T2-T12, T5-T12). Spine flexibility was assessed on prone bending x-rays. Apical axial rotation was determined on CT scans obtained intraoperatively and postoperatively. Rotation angle (RAsag) was measured according to Aaro and Dahlborn. We observed reduction of RAsag in all patients; however, in DVR group, decrease was greater, by 31.8% comparing to non-DVR group, by 8.6% (p = 0.0003). Mean coronal correction in DVR group was 68.8% and in rod derotation group without DVR 55% (p = 0.002). No significant correlation was found between degree of derotation obtained and coronal correction. In DVR group T2-T12 kyphosis has increased in 28 (65%) patients whereas in non-DVR group in 31 (69%) cases. Mean value of T2-T12 kyphosis growth was 16.7% in DVR and 22.1% in non-DVR group. These differences however did not occur statistically significant. Direct vertebral rotation (DVR) maneuver reduces significantly apical rotation of the spine, enhances ability of coronal correction, and it does not reduce thoracic kyphosis.

Compensation of Gaussian curvature in developable cones is local

NASA Astrophysics Data System (ADS)

Wang, Jin W.; Witten, Thomas A.

2009-10-01

We use the angular deficit scheme [V. Borrelli, F. Cazals, and J.-M. Morvan, Comput. Aided Geom. Des. 20, 319 (2003)] to determine the distribution of Gaussian curvature in developable cones (d-cones) [E. Cerda, S. Chaieb, F. Melo, and L. Mahadevan, Nature (London) 401, 46 (1999)] numerically. These d-cones are formed by pushing a thin elastic sheet into a circular container. Negative Gaussian curvatures are identified at the rim where the sheet touches the container. Around the rim there are two narrow bands with positive Gaussian curvatures. The integral of the (negative) Gaussian curvature near the rim is almost completely compensated by that of the two adjacent bands. This suggests that the Gauss-Bonnet theorem which constrains the integral of Gaussian curvature globally does not explain the spontaneous curvature cancellation phenomenon [T. Liang and T. A. Witten, Phys. Rev. E 73, 046604 (2006)]. The locality of the compensation seems to increase for decreasing d-cone thickness. The angular deficit scheme also provides a way to confirm the curvature cancellation phenomenon.

Quantitative photogrammetric analysis of the Klapp method for treating idiopathic scoliosis.

PubMed

Iunes, Denise H; Cecílio, Maria B B; Dozza, Marina A; Almeida, Polyanna R

2010-01-01

Few studies have proved that physical therapy techniques are efficient in the treatment of scoliosis. To analyze the efficiency of the Klapp method for the treatment of scoliosis, through a quantitative analysis using computerized biophotogrammetry. Sixteen participants of a mean age of 15+/-2.61 yrs. with idiopathic scoliosis were treated using the Klapp method. To analyze the results from the treatment, they were all of photographed before and after the treatments, following a standardized photographic method. All of the photographs were analyzed quantitatively by the same examiner using the ALCimagem 2000 software. The statistical analyses were performed using the paired t-test with a significance level of 5%. The treatments showed improvements in the angles which evaluated the symmetry of the shoulders, i.e. the acromioclavicular joint angle (AJ; p=0.00) and sternoclavicular joint angle (SJ; p=0.01). There were also improvements in the angle that evaluated the left Thales triangle (DeltaT; p=0.02). Regarding flexibility, there were improvements in the tibiotarsal angle (TTA; p=0.01) and in the hip joint angles (HJA; p=0.00). There were no changes in the vertebral curvatures and nor improvements in head positioning. Only the lumbar curvature, evaluated by the lumbar lordosis angle (LL; p=0.00), changed after the treatments. The Klapp method was an efficient therapeutic technique for treating asymmetries of the trunk and improving its flexibility. However, it was not efficient for pelvic asymmetry modifications in head positioning, cervical lordosis or thoracic kyphosis.

Graph Curvature for Differentiating Cancer Networks

PubMed Central

Sandhu, Romeil; Georgiou, Tryphon; Reznik, Ed; Zhu, Liangjia; Kolesov, Ivan; Senbabaoglu, Yasin; Tannenbaum, Allen

2015-01-01

Cellular interactions can be modeled as complex dynamical systems represented by weighted graphs. The functionality of such networks, including measures of robustness, reliability, performance, and efficiency, are intrinsically tied to the topology and geometry of the underlying graph. Utilizing recently proposed geometric notions of curvature on weighted graphs, we investigate the features of gene co-expression networks derived from large-scale genomic studies of cancer. We find that the curvature of these networks reliably distinguishes between cancer and normal samples, with cancer networks exhibiting higher curvature than their normal counterparts. We establish a quantitative relationship between our findings and prior investigations of network entropy. Furthermore, we demonstrate how our approach yields additional, non-trivial pair-wise (i.e. gene-gene) interactions which may be disrupted in cancer samples. The mathematical formulation of our approach yields an exact solution to calculating pair-wise changes in curvature which was computationally infeasible using prior methods. As such, our findings lay the foundation for an analytical approach to studying complex biological networks. PMID:26169480

Curvature from Strong Gravitational Lensing: A Spatially Closed Universe or Systematics?

NASA Astrophysics Data System (ADS)

Li, Zhengxiang; Ding, Xuheng; Wang, Guo-Jian; Liao, Kai; Zhu, Zong-Hong

2018-02-01

Model-independent constraints on the spatial curvature are not only closely related to important problems, such as the evolution of the universe and properties of dark energy, but also provide a test of the validity of the fundamental Copernican principle. In this paper, with the distance sum rule in the Friedmann–Lemaître–Robertson–Walker metric, we achieve model-independent measurements of the spatial curvature from the latest type Ia supernovae and strong gravitational lensing (SGL) observations. We find that a spatially closed universe is preferred. Moreover, by considering different kinds of velocity dispersion and subsamples, we study possible factors that might affect model-independent estimations for the spatial curvature from SGL observations. It is suggested that the combination of observational data from different surveys might cause a systematic bias, and the tension between the spatially flat universe and SGL observations is alleviated when the subsample only from the Sloan Lens ACS Survey is used or a more complex treatment for the density profile of lenses is considered.

FY 2016 Status Report: CIRFT Testing Data Analyses and Updated Curvature Measurements

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

Wang, Jy-An John; Wang, Hong

This report provides a detailed description of FY15 test result corrections/analysis based on the FY16 Cyclic Integrated Reversible-Bending Fatigue Tester (CIRFT) test program methodology update used to evaluate the vibration integrity of spent nuclear fuel (SNF) under normal transportation conditions. The CIRFT consists of a U-frame testing setup and a real-time curvature measurement method. The three-component U-frame setup of the CIRFT has two rigid arms and linkages to a universal testing machine. The curvature of rod bending is obtained through a three-point deflection measurement method. Three linear variable differential transformers (LVDTs) are used and clamped to the side connecting platesmore » of the U-frame to capture the deformation of the rod. The contact-based measurement, or three-LVDT-based curvature measurement system, on SNF rods has been proven to be quite reliable in CIRFT testing. However, how the LVDT head contacts the SNF rod may have a significant effect on the curvature measurement, depending on the magnitude and direction of rod curvature. It has been demonstrated that the contact/curvature issues can be corrected by using a correction on the sensor spacing. The sensor spacing defines the separation of the three LVDT probes and is a critical quantity in calculating the rod curvature once the deflections are obtained. The sensor spacing correction can be determined by using chisel-type probes. The method has been critically examined this year and has been shown to be difficult to implement in a hot cell environment, and thus cannot be implemented effectively. A correction based on the proposed equivalent gauge-length has the required flexibility and accuracy and can be appropriately used as a correction factor. The correction method based on the equivalent gauge length has been successfully demonstrated in CIRFT data analysis for the dynamic tests conducted on Limerick (LMK) (17 tests), North Anna (NA) (6 tests), and Catawba mixed oxide

Orthopedic Management of Scoliosis by Garches Brace and Spinal Fusion in SMA Type 2 Children.

PubMed

Catteruccia, Michela; Vuillerot, Carole; Vaugier, Isabelle; Leclair, Danielle; Azzi, Viviane; Viollet, Louis; Estournet, Brigitte; Bertini, Enrico; Quijano-Roy, Susana

2015-11-21

Scoliosis is the most debilitating issue in SMA type 2 patients. No evidence confirms the efficacy of Garches braces (GB) to delay definitive spinal fusion. Compare orthopedic and pulmonary outcomes in children with SMA type 2 function to management. We carried out a monocentric retrospective study on 29 SMA type 2 children who had spinal fusion between 1999 and 2009. Patients were divided in 3 groups: group 1-French patients (12 children) with a preventive use of GB; group 2-French patients (10 children) with use of GB after the beginning of the scoliosis curve; and group 3-Italian patients (7 children) with use of GB after the beginning of the scoliosis curve referred to our centre to perform orthopedic preoperative management. Mean preoperative and postoperative Cobb angle were significantly lower in the group 1 of proactively braced than in group 2 or 3 (Anova p = 0.03; Kruskal Wallis test p = 0.05). Better surgical results were observed in patients with a minor preoperative Cobb angle (r = 0.92 p <  0.0001). Fewer patients in the group 1 proactively braced required trunk casts and/or halo traction and an additional anterior fusion in comparison with patients in the group 2 and 3. Moreover, major complications tend to be less in the group 1 proactively braced. No significant differences were found between groups in pulmonary outcome measures. A proactive orthotic management may improve orthopedic outcome in SMA type 2. Further prospective studies comparing SMA management are needed to confirm these results. Therapeutic Level III. See Instructions to Authors on jbjs.org for a complete description of levels of evidence (Retrospective comparative study).

Is There Asymmetry Between the Concave and Convex Pedicles in Adolescent Idiopathic Scoliosis? A CT Investigation.

PubMed

Davis, Colin M; Grant, Caroline A; Pearcy, Mark J; Askin, Geoffrey N; Labrom, Robert D; Izatt, Maree T; Adam, Clayton J; Little, J Paige

2017-03-01

Adolescent idiopathic scoliosis is a complex three-dimensional deformity of the spine characterized by deformities in the sagittal, coronal, and axial planes. Spinal fusion using pedicle screw instrumentation is a widely used method for surgical correction in severe (coronal deformity, Cobb angle > 45°) adolescent idiopathic scoliosis curves. Understanding the anatomic difference in the pedicles of patients with adolescent idiopathic scoliosis is essential to reduce the risk of neurovascular or visceral injury through pedicle screw misplacement. To use CT scans (1) to analyze pedicle anatomy in the adolescent thoracic scoliotic spine comparing concave and convex pedicles and (2) to assess the intra- and interobserver reliability of these measurements to provide critical information to spine surgeons regarding size, length, and angle of projection. Between 2007 and 2009, 27 patients with adolescent idiopathic scoliosis underwent thoracoscopic anterior correction surgery by two experienced spinal surgeons. Preoperatively, each patient underwent a CT scan as was their standard of care at that time. Twenty-two patients (mean age, 15.7 years; SD, 2.4 years; range, 11.6-22 years) (mean Cobb angle, 53°; SD, 5.3°; range, 42°-63°) were selected. Inclusion criteria were a clinical diagnosis of adolescent idiopathic scoliosis, female, and Lenke type 1 adolescent idiopathic scoliosis with the major curve confined to the thoracic spine. Using three-dimensional image analysis software, the pedicle width, inner cortical pedicle width, pedicle height, inner cortical pedicle height, pedicle length, chord length, transverse pedicle angle, and sagittal pedicle angles were measured. Randomly selected scans were remeasured by two of the authors and the reproducibility of the measurement definitions was validated through limit of agreement analysis. The concave pedicle widths were smaller compared with the convex pedicle widths at T7, T8, and T9 by 37% (3.44 mm ± 1.16 mm vs 4

Curvature Continuous and Bounded Path Planning for Fixed-Wing UAVs.

PubMed

Wang, Xiaoliang; Jiang, Peng; Li, Deshi; Sun, Tao

2017-09-19

Unmanned Aerial Vehicles (UAVs) play an important role in applications such as data collection and target reconnaissance. An accurate and optimal path can effectively increase the mission success rate in the case of small UAVs. Although path planning for UAVs is similar to that for traditional mobile robots, the special kinematic characteristics of UAVs (such as their minimum turning radius) have not been taken into account in previous studies. In this paper, we propose a locally-adjustable, continuous-curvature, bounded path-planning algorithm for fixed-wing UAVs. To deal with the curvature discontinuity problem, an optimal interpolation algorithm and a key-point shift algorithm are proposed based on the derivation of a curvature continuity condition. To meet the upper bound for curvature and to render the curvature extrema controllable, a local replanning scheme is designed by combining arcs and Bezier curves with monotonic curvature. In particular, a path transition mechanism is built for the replanning phase using minimum curvature circles for a planning philosophy. Numerical results demonstrate that the analytical planning algorithm can effectively generate continuous-curvature paths, while satisfying the curvature upper bound constraint and allowing UAVs to pass through all predefined waypoints in the desired mission region.

Relation between adolescent idiopathic scoliosis and morphologic somatotypes.

PubMed

LeBlanc, R; Labelle, H; Rivard, C H; Poitras, B

1997-11-01

A prospective and controlled comparative study. To verify the difference in morphologic appearance between a group of adolescents with progressive adolescent idiopathic scoliosis and a control group of normal adolescents. In a previous retrospective study, the possibility of a relation between progressive adolescent idiopathic scoliosis and specific morphotypes was demonstrated. Fifty-two adolescent girls with progressive adolescent idiopathic scoliosis were compared with an age-matched control group of 62 unaffected girls using a classification technique based on morphologic somatotypes. Morphotypes were evaluated with standardized pre-established criteria based on Sheldon's technique. Patients with progressive adolescent idiopathic scoliosis showed significantly less mesomorphism (mean value of 0.88 +/- 0.51) than control girls (mean value of 1.72 +/- 0.52). Adolescent girls with progressive adolescent idiopathic scoliosis have a morphologic somatotype that is different from the normal adolescent population. Subjects with progressive adolescent idiopathic scoliosis are significantly less mesomorphic than control girls. This observation may be of value as a predictive factor for early identification of subjects with adolescent idiopathic scoliosis at greater risk of progression.

Novel tilt-curvature coupling in lipid membranes

NASA Astrophysics Data System (ADS)

Terzi, M. Mert; Deserno, Markus

2017-08-01

On mesoscopic scales, lipid membranes are well described by continuum theories whose main ingredients are the curvature of a membrane's reference surface and the tilt of its lipid constituents. In particular, Hamm and Kozlov [Eur. Phys. J. E 3, 323 (2000)] have shown how to systematically derive such a tilt-curvature Hamiltonian based on the elementary assumption of a thin fluid elastic sheet experiencing internal lateral pre-stress. Performing a dimensional reduction, they not only derive the basic form of the effective surface Hamiltonian but also express its emergent elastic couplings as trans-membrane moments of lower-level material parameters. In the present paper, we argue, though, that their derivation unfortunately missed a coupling term between curvature and tilt. This term arises because, as one moves along the membrane, the curvature-induced change of transverse distances contributes to the area strain—an effect that was believed to be small but nevertheless ends up contributing at the same (quadratic) order as all other terms in their Hamiltonian. We illustrate the consequences of this amendment by deriving the monolayer and bilayer Euler-Lagrange equations for the tilt, as well as the power spectra of shape, tilt, and director fluctuations. A particularly curious aspect of our new term is that its associated coupling constant is the second moment of the lipid monolayer's lateral stress profile—which within this framework is equal to the monolayer Gaussian curvature modulus, κ¯ m. On the one hand, this implies that many theoretical predictions now contain a parameter that is poorly known (because the Gauss-Bonnet theorem limits access to the integrated Gaussian curvature); on the other hand, the appearance of κ¯ m outside of its Gaussian curvature provenance opens opportunities for measuring it by more conventional means, for instance by monitoring a membrane's undulation spectrum at short scales.

Novel tilt-curvature coupling in lipid membranes.

PubMed

Terzi, M Mert; Deserno, Markus

2017-08-28

On mesoscopic scales, lipid membranes are well described by continuum theories whose main ingredients are the curvature of a membrane's reference surface and the tilt of its lipid constituents. In particular, Hamm and Kozlov [Eur. Phys. J. E 3, 323 (2000)] have shown how to systematically derive such a tilt-curvature Hamiltonian based on the elementary assumption of a thin fluid elastic sheet experiencing internal lateral pre-stress. Performing a dimensional reduction, they not only derive the basic form of the effective surface Hamiltonian but also express its emergent elastic couplings as trans-membrane moments of lower-level material parameters. In the present paper, we argue, though, that their derivation unfortunately missed a coupling term between curvature and tilt. This term arises because, as one moves along the membrane, the curvature-induced change of transverse distances contributes to the area strain-an effect that was believed to be small but nevertheless ends up contributing at the same (quadratic) order as all other terms in their Hamiltonian. We illustrate the consequences of this amendment by deriving the monolayer and bilayer Euler-Lagrange equations for the tilt, as well as the power spectra of shape, tilt, and director fluctuations. A particularly curious aspect of our new term is that its associated coupling constant is the second moment of the lipid monolayer's lateral stress profile-which within this framework is equal to the monolayer Gaussian curvature modulus, κ¯ m . On the one hand, this implies that many theoretical predictions now contain a parameter that is poorly known (because the Gauss-Bonnet theorem limits access to the integrated Gaussian curvature); on the other hand, the appearance of κ¯ m outside of its Gaussian curvature provenance opens opportunities for measuring it by more conventional means, for instance by monitoring a membrane's undulation spectrum at short scales.

Cervical curvature variations in patients with infraocclusion.

PubMed

Ando, E; Shigeta, Y; Hirabayashi, R; Ikawa, T; Hirai, S; Katsumura, S; Ogawa, T

2014-08-01

The purpose of this study was to observe the variations of cervical curvature in patients with infraocclusion, and to compare this with the controls. In this study, the infraocclusion criteria were defined with the Pr-id as <17 mm on the cephalometric image. The subjects were 32 patients with infraocclusion, and 28 controls which matched the distribution for gender and age. The six points of inquiry were as follows: (i) cervical vertebra height, (ii) neck alignment, (iii) ratio of lower facial height, (iv) vertical dimension of occlusion, (v) cervical angle and (vi) occlusal angle. In over 90% of the patients with infraocclusion, the cervical curvature was classified as straight or kyphosis. Conversely, in 36% of the control subjects, the cervical curvature was classified as lordosis. There was a weak positive correlation between the vertical dimension of occlusion and the cervical curvature in all subjects. In the control group, there was a significant and strong positive correlation between the age and cervical curvature, and a strong negative correlation between age and cervical angle and occlusal angle. Conversely, in the patients with infraocclusion, age was only correlated with the ratio of lower facial height. The prevalence of non-lordosis in the patients with infraocclusion was higher in comparison with the control group in our study, and the previous large-scale study of Japanese. However, there was merely a weak positive correlation between the cervical curvature and the vertical dimension of occlusion. © 2014 John Wiley & Sons Ltd.

Curvature constraints from the causal entropic principle

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

Bozek, Brandon; Albrecht, Andreas; Phillips, Daniel

2009-07-15

Current cosmological observations indicate a preference for a cosmological constant that is drastically smaller than what can be explained by conventional particle physics. The causal entropic principle (Bousso et al.) provides an alternative approach to anthropic attempts to predict our observed value of the cosmological constant by calculating the entropy created within a causal diamond. We have extended this work to use the causal entropic principle to predict the preferred curvature within the 'multiverse'. We have found that values larger than {rho}{sub k}=40{rho}{sub m} are disfavored by more than 99.99% peak value at {rho}{sub {lambda}}=7.9x10{sup -123} and {rho}{sub k}=4.3{rho}{sub m}more » for open universes. For universes that allow only positive curvature or both positive and negative curvature, we find a correlation between curvature and dark energy that leads to an extended region of preferred values. Our universe is found to be disfavored to an extent depending on the priors on curvature. We also provide a comparison to previous anthropic constraints on open universes and discuss future directions for this work.« less

Perspective: Update on Idiopathic Intracranial Hypertension

PubMed Central

Bruce, Beau B.; Biousse, Valérie; Newman, Nancy J.

2011-01-01

Purpose Provide an update on various features of idiopathic intracranial hypertension. Design Perspective. Methods Selected articles on the epidemiology, clinical and imaging features, natural history, pathophysiology, and treatment of idiopathic intracranial hypertension were reviewed and interpreted in the context of the authors’ clinical and research experience. Results Idiopathic intracranial hypertension is primarily a disease of obese women of childbearing age, but it can affect patients of any weight, sex, and age. Although a relatively rare disorder, idiopathic intracranial hypertension’s associated costs in the U.S. entail hundreds of millions of dollars. Even following treatment, headaches are frequently persistent and may require the continued involvement of a neurologist. Quality of life reductions and depression are common among idiopathic intracranial hypertension patients. However, visual dysfunction, especially visual field abnormalities, represents the major morbidity of this disorder, and serial automated perimetry remains the primary mode of patient monitoring. Patients who are men, black, very obese, or anemic are at higher risk of visual loss. Vitamin A metabolism, adipose tissue as an actively secreting endocrine tissue, and cerebral venous abnormalities are areas of active study regarding idiopathic intracranial hypertension’s pathophysiology. Treatment studies show that lumbar puncture is a valuable treatment (in addition to its crucial diagnostic role) and that weight management is critical. However, open questions remain regarding the efficacy of acetazolamide, CSF diversion procedures, and cerebral venous stenting. Conclusions Many questions remain unanswered about idiopathic intracranial hypertension. Ongoing studies, especially an ongoing NIH-funded clinical trial of acetazolamide, should provide more insight into this important, yet poorly understood syndrome of isolated intracranial hypertension. PMID:21696699

Quantifying phalangeal curvature: an empirical comparison of alternative methods.

PubMed

Stern, J T; Jungers, W L; Susman, R L

1995-05-01

It has been generally assumed and theoretically argued that the curvature of finger and toe bones seen in some nonhuman primates is associated with cheiridial use in an arboreal setting. Assessment of such curvature in fossil primates has been used to infer the positional behavior of these animals. Several methods of quantifying curvature of bones have been proposed. The measure most commonly applied to phalanges is that of included angle, but this has come under some criticism. We consider various other approaches for quantifying phalangeal curvature, demonstrating that some are equivalent to use of included angle, but that one--normalized curvature moment arm (NCMA)--represents a true alternative. A comparison of NCMA to included angle, both calculated on manual and pedal proximal phalanges of humans, apes, some monkeys, and the Hadar fossils, revealed that these two different measures of curvature are highly correlated and result in very similar distributional patterns.

Dorsal–Ventral Gradient for Neuronal Plasticity in the Embryonic Spinal Cord

PubMed Central

Pineda, Ricardo H.; Ribera, Angeles B.

2008-01-01

Within the developing Xenopus spinal cord, voltage-gated potassium (Kv) channel genes display different expression patterns, many of which occur in opposing dorsal–ventral gradients. Regional differences in Kv gene expression would predict different patterns of potassium current (IKv) regulation. However, during the first 24 h of postmitotic differentiation, all primary spinal neurons undergo a temporally coordinated upregulation of IKv density that shortens the duration of the action potential. Here, we tested whether spinal neurons demonstrate regional differences in IKv regulation subsequent to action potential maturation. We show that two types of neurons, I and II, can be identified in culture on the basis of biophysical and pharmacological properties of IKv and different firing patterns. Chronic increases in extracellular potassium, a signature of high neuronal activity, do not alter excitability properties of either neuron type. However, elevating extracellular potassium acutely after the period of action potential maturation leads to different changes in membrane properties of the two types of neurons. IKv of type I neurons gains sensitivity to the blocker XE991, whereas type II neurons increase IKv density and fire fewer action potentials. Moreover, by recording from neurons in vivo, we found that primary spinal neurons can be identified as either type I or type II. Type I neurons predominate in dorsal regions, whereas type II neurons localize to ventral regions. The findings reveal a dorsal–ventral gradient for IKv regulation and a novel form of neuronal plasticity in spinal cord neurons. PMID:18385340

Whither the etiopathogenesis (and scoliogeny) of adolescent idiopathic scoliosis? Incorporating presentations on scoliogeny at the 2012 IRSSD and SRS meetings

PubMed Central

2013-01-01

This paper aims to integrate into current understanding of AIS causation, etiopathogenetic information presented at two Meetings during 2012 namely, the International Research Society of Spinal Deformities (IRSSD) and the Scoliosis Research Society (SRS). The ultimate hope is to prevent the occurrence or progression of the spinal deformity of AIS with non-invasive treatment, possibly medical. This might be attained by personalised polymechanistic preventive therapy targeting the appropriate etiology and/or etiopathogenetic pathways, to avoid fusion and maintain spinal mobility. Although considerable progress had been made in the past two decades in understanding the etiopathogenesis of adolescent idiopathic scoliosis (AIS), it still lacks an agreed theory of etiopathogenesis. One problem may be that AIS results not from one cause, but several that interact with various genetic predisposing factors. There is a view there are two other pathogenic processes for idiopathic scoliosis namely, initiating (or inducing), and those that cause curve progression. Twin studies and observations of family aggregation have revealed significant genetic contributions to idiopathic scoliosis, that place AIS among other common disease or complex traits with a high heritability interpreted by the genetic variant hypothesis of disease. We summarize etiopathogenetic knowledge of AIS as theories of pathogenesis including recent multiple concepts, and blood tests for AIS based on predictive biomarkers and genetic variants that signify disease risk. There is increasing evidence for the possibility of an underlying neurological disorder for AIS, research which holds promise. Like brain research, most AIS workers focus on their own corner and there is a need for greater integration of research effort. Epigenetics, a relatively recent field, evaluates factors concerned with gene expression in relation to environment, disease, normal development and aging, with a complex regulation across the

Relationship between thoracic hypokyphosis, lumbar lordosis and sagittal pelvic parameters in adolescent idiopathic scoliosis.

PubMed

Clément, Jean-Luc; Geoffray, Anne; Yagoubi, Fatima; Chau, Edouard; Solla, Federico; Oborocianu, Ioana; Rampal, Virginie

2013-11-01

Sagittal spine and pelvic alignment of adolescent idiopathic scoliosis (AIS) is poorly described in the literature. It generally reports the sagittal alignment with regard to the type of curve and never correlated to the thoracic kyphosis. The objective of this study is to investigate the relationship between thoracic kyphosis, lumbar lordosis and sagittal pelvic parameters in thoracic AIS. Spinal and pelvic sagittal parameters were evaluated on lateral radiographs of 86 patients with thoracic AIS; patients were separated into hypokyphosis group (n = 42) and normokyphosis group (n = 44). Results were statistically analyzed. The lumbar lordosis was lower in the hypokyphosis group, due to the low proximal lordosis. The thoracic kyphosis was not correlated with any pelvic parameters but with the proximal lordosis. The pelvic incidence was correlated with sacral slope, pelvic tilt, lumbar lordosis and highly correlated with distal lumbar lordosis in the two groups. There was a significant linear regression between thoracic kyphosis and proximal lordosis and between pelvic incidence and distal lordosis. We can consider that the proximal part of the lordosis depends on the thoracic kyphosis and the distal part depends on the pelvic incidence. The hypokyphosis in AIS is independent of the pelvic parameters and could be described as a structural parameter, characteristic of the scoliotic deformity.

Multiple intracranial calcifications and spinal compressions: rare complications of type la pseudohypoparathyroidism.

PubMed

Chen, H; Tseng, F; Su, D; Chen, H; Tsai, K

2005-01-01

Type la pseudohypoparathyroidism (PHP la) is an unusual inherited disease. PHP la often causes extraskeletal calcifications and even soft tissue ossifications. Patients may present neurologic symptoms and signs related to hypocalcemia and hyperphosphatemia. We report here a 38-yr-old woman with PHP la who had two uncommon neurologic complications. One was involuntary movements related to basal ganglia calcification, and the other was myelopathy owing to ossifications of the posterior longitudinal ligament and multiple herniated intervertebral disks. Aggressive body weight control and corrections of hypocalcemia, hyperphosphatemia, and elevated PTH may be important to prevent these unusual neurologic complications. Regular and careful neurologic examinations should be performed for early diagnosis and treatments of these spinal lesions.

Asymptotic behavior of curvature of surface elements in isotropic turbulence

NASA Technical Reports Server (NTRS)

Girimaji, S. S.

1991-01-01

The asymptotic behavior of the curvature of material elements in turbulence is investigated using Lagrangian velocity-gradient time series obtained from direct numerical simulations of isotropic turbulence. Several material-element ensembles of different initial curvatures and shapes are studied. It is found that, at long times, the (first five) moments of the logarithm of characteristic curvature and shape factor asymptote to values that are independent of the initial curvature or shape. This evidence strongly suggests that the asymptotic pdf's of the curvature and shape of material elements are stationary and independent of initial conditions. Irrespective of initial curvature or shape, the asymptotic shape of a material surface is cylindrical with a high probability.

Robust pupil center detection using a curvature algorithm

NASA Technical Reports Server (NTRS)

Zhu, D.; Moore, S. T.; Raphan, T.; Wall, C. C. (Principal Investigator)

1999-01-01

Determining the pupil center is fundamental for calculating eye orientation in video-based systems. Existing techniques are error prone and not robust because eyelids, eyelashes, corneal reflections or shadows in many instances occlude the pupil. We have developed a new algorithm which utilizes curvature characteristics of the pupil boundary to eliminate these artifacts. Pupil center is computed based solely on points related to the pupil boundary. For each boundary point, a curvature value is computed. Occlusion of the boundary induces characteristic peaks in the curvature function. Curvature values for normal pupil sizes were determined and a threshold was found which together with heuristics discriminated normal from abnormal curvature. Remaining boundary points were fit with an ellipse using a least squares error criterion. The center of the ellipse is an estimate of the pupil center. This technique is robust and accurately estimates pupil center with less than 40% of the pupil boundary points visible.

Curvature Continuous and Bounded Path Planning for Fixed-Wing UAVs

PubMed Central

Jiang, Peng; Li, Deshi; Sun, Tao

2017-01-01

Unmanned Aerial Vehicles (UAVs) play an important role in applications such as data collection and target reconnaissance. An accurate and optimal path can effectively increase the mission success rate in the case of small UAVs. Although path planning for UAVs is similar to that for traditional mobile robots, the special kinematic characteristics of UAVs (such as their minimum turning radius) have not been taken into account in previous studies. In this paper, we propose a locally-adjustable, continuous-curvature, bounded path-planning algorithm for fixed-wing UAVs. To deal with the curvature discontinuity problem, an optimal interpolation algorithm and a key-point shift algorithm are proposed based on the derivation of a curvature continuity condition. To meet the upper bound for curvature and to render the curvature extrema controllable, a local replanning scheme is designed by combining arcs and Bezier curves with monotonic curvature. In particular, a path transition mechanism is built for the replanning phase using minimum curvature circles for a planning philosophy. Numerical results demonstrate that the analytical planning algorithm can effectively generate continuous-curvature paths, while satisfying the curvature upper bound constraint and allowing UAVs to pass through all predefined waypoints in the desired mission region. PMID:28925960

General Information about Childhood Brain and Spinal Cord Tumors

MedlinePlus

... Cord Tumors Treatment Overview (PDQ®)–Patient Version General Information About Childhood Brain and Spinal Cord Tumors Go ... types of brain and spinal cord tumors. The information from tests and procedures done to detect (find) ...

Transcranial magnetic stimulation in the semi-quantitative, pre-operative assessment of patients undergoing spinal deformity surgery.

PubMed

Glasby, Michael A; Tsirikos, Athanasios I; Henderson, Lindsay; Horsburgh, Gillian; Jordan, Brian; Michaelson, Ciara; Adams, Christopher I; Garrido, Enrique

2017-08-01

To compare measurements of motor evoked potential latency stimulated either magnetically (mMEP) or electrically (eMEP) and central motor conduction time (CMCT) made pre-operatively in conscious patients using transcranial and intra-operatively using electrical cortical stimulation before and after successful instrumentation for the treatment of adolescent idiopathic scoliosis. A group initially of 51 patients with adolescent idiopathic scoliosis aged 12-19 years was evaluated pre-operatively in the outpatients' department with transcranial magnetic stimulation. The neurophysiological data were then compared statistically with intra-operative responses elicited by transcranial electrical stimulation both before and after successful surgical intervention. MEPs were measured as the cortically evoked compound action potentials of Abductor hallucis. Minimum F-waves were measured using conventional nerve conduction methods and the lower motor neuron conduction time was calculated and this was subtracted from MEP latency to give CMCT. Pre-operative testing was well tolerated in our paediatric/adolescent patients. No neurological injury occurred in any patient in this series. There was no significant difference in the values of mMEP and eMEP latencies seen pre-operatively in conscious patients and intra-operatively in patients under anaesthetic. The calculated quantities mCMCT and eCMCT showed the same statistical correlations as the quantities mMEP and eMEP latency. The congruency of mMEP and eMEP and of mCMCT and eCMCT suggests that these measurements may be used comparatively and semi-quantitatively for the comparison of pre-, intra-, and post-operative spinal cord function in spinal deformity surgery.

The Natural History of Idiopathic Scoliosis During Growth: A Meta-Analysis.

PubMed

Di Felice, Francesca; Zaina, Fabio; Donzelli, Sabrina; Negrini, Stefano

2018-05-01

The aim of the study was to provide a meta-analysis of current literature concerning the natural history of idiopathic scoliosis during growth. A comprehensive search of Medline, Embase, And Scopus databases was conducted up to November 2016. Eligible works were prospective or retrospective studies that enrolled patients with infantile idiopathic scoliosis, juvenile idiopathic scoliosis, or adolescent idiopathic scoliosis, followed up without any treatment from the time of detection. A meta-analysis for proportion was performed. The following studies were grouped per diagnosis: infantile idiopathic scoliosis, juvenile idiopathic scoliosis, and adolescent idiopathic scoliosis. Of the 1797 citations screened, we assessed 61 full-text articles and included 13 of these (2301 participants). Three studies included infantile idiopathic scoliosis patients (347 participants), five studies included a mixed population of juvenile idiopathic scoliosis and adolescent idiopathic scoliosis (1330 participants), and five studies included adolescent idiopathic scoliosis patients only (624 participants). The random pooled estimated progression rate was 49% (95% confidence interval = 1%-97%) for infantile idiopathic scoliosis, 49% in a mixed group of patients affected by juvenile idiopathic scoliosis or adolescent idiopathic scoliosis (95% confidence interval = 19%-79%), and 42% in adolescent idiopathic scoliosis (95% confidence interval = 11%-73%). During growth, idiopathic scoliosis tends to progress in a high percentage of cases. The progression rate varies according to the age at diagnosis, with infantile scoliosis being the most unpredictable. There are many confounders, such as age, Risser sign and baseline Cobb angles that were not consistent among studies, making the data very heterogeneous.

Long-term outcomes of anterior spinal fusion for treating thoracic adolescent idiopathic scoliosis curves: average 15-year follow-up analysis.

PubMed

Sudo, Hideki; Ito, Manabu; Kaneda, Kiyoshi; Shono, Yasuhiro; Takahata, Masahiko; Abumi, Kuniyoshi

2013-05-01

Retrospective review. To assess the long-term outcomes of anterior spinal fusion (ASF) for treating thoracic adolescent idiopathic scoliosis (AIS). Although ASF is reported to provide good coronal and sagittal correction of the main thoracic (MT) AIS curves, the long-term outcomes of ASF is unknown. A consecutive series of 25 patients with Lenke 1 MT AIS were included. Outcome measures comprised radiographical measurements, pulmonary function, and Scoliosis Research Society outcome instrument (SRS-30) scores (preoperative SRS-30 scores were not documented). Postoperative surgical revisions and complications were recorded. Twenty-five patients were followed-up for 12 to 18 years (average, 15.2 yr). The average MT Cobb angle correction rate and the correction loss at the final follow-up were 56.7% and 9.2°, respectively. The average preoperative instrumented level of kyphosis was 8.3°, which significantly improved to 18.6° (P = 0.0003) at the final follow-up. The average percent-predicted forced vital capacity and forced expiratory volume in 1 second were significantly decreased during long-term follow-up measurements (73% and 69%; P = 0.0004 and 0.0016, respectively). However, no patient had complaints related to pulmonary function. The average total SRS-30 score was 4.0. Implant breakage was not observed. All patients, except 1 who required revision surgery, demonstrated solid fusion. Late instrumentation-related bronchial problems were observed in 1 patient who required implant removal and bronchial tube repair, 13 years after the initial surgery. Overall radiographical findings and patient outcome measures of ASF for Lenke 1 MT AIS were satisfactory at an average follow-up of 15 years. ASF provides significant sagittal correction of the main thoracic curve with long-term maintenance of sagittal profiles. Percent-predicted values of forced vital capacity and forced expiratory volume in 1 second were decreased in this cohort; however, no patient had complaints

Inverse curvature flows in asymptotically Robertson Walker spaces

NASA Astrophysics Data System (ADS)

Kröner, Heiko

2018-04-01

In this paper we consider inverse curvature flows in a Lorentzian manifold N which is the topological product of the real numbers with a closed Riemannian manifold and equipped with a Lorentzian metric having a future singularity so that N is asymptotically Robertson Walker. The flow speeds are future directed and given by 1 / F where F is a homogeneous degree one curvature function of class (K*) of the principal curvatures, i.e. the n-th root of the Gauss curvature. We prove longtime existence of these flows and that the flow hypersurfaces converge to smooth functions when they are rescaled with a proper factor which results from the asymptotics of the metric.

Patient-specific 3D models created by 3D imaging system or bi-planar imaging coupled with Moiré-Fringe projections: a comparative study of accuracy and reliability on spinal curvatures and vertebral rotation data.

PubMed

Hocquelet, Arnaud; Cornelis, François; Jirot, Anna; Castaings, Laurent; de Sèze, Mathieu; Hauger, Olivier

2016-10-01

The aim of this study is to compare the accuracy and reliability of spinal curvatures and vertebral rotation data based on patient-specific 3D models created by 3D imaging system or by bi-planar imaging coupled with Moiré-Fringe projections. Sixty-two consecutive patients from a single institution were prospectively included. For each patient, frontal and sagittal calibrated low-dose bi-planar X-rays were performed and coupled simultaneously with an optical Moiré back surface-based technology. The 3D reconstructions of spine and pelvis were performed independently by one radiologist and one technician in radiology using two different semi-automatic methods using 3D radio-imaging system (method 1) or bi-planar imaging coupled with Moiré projections (method 2). Both methods were compared using Bland-Altman analysis, and reliability using intraclass correlation coefficient (ICC). ICC showed good to very good agreement. Between the two techniques, the maximum 95 % prediction limits was -4.9° degrees for the measurements of spinal coronal curves and less than 5° for other parameters. Inter-rater reliability was excellent for all parameters across both methods, except for axial rotation with method 2 for which ICC was fair. Method 1 was faster for reconstruction time than method 2 for both readers (13.4 vs. 20.7 min and 10.6 vs. 13.9 min; p = 0.0001). While a lower accuracy was observed for the evaluation of the axial rotation, bi-planar imaging coupled with Moiré-Fringe projections may be an accurate and reliable tool to perform 3D reconstructions of the spine and pelvis.

3D curvature of muscle fascicles in triceps surae

PubMed Central

Hamarneh, Ghassan; Wakeling, James M.

2014-01-01

Muscle fascicles curve along their length, with the curvatures occurring around regions of high intramuscular pressure, and are necessary for mechanical stability. Fascicles are typically considered to lie in fascicle planes that are the planes visualized during dissection or two-dimensional (2D) ultrasound scans. However, it has previously been predicted that fascicles must curve in three-dimensional (3D) and thus the fascicle planes may actually exist as 3D sheets. 3D fascicle curvatures have not been explored in human musculature. Furthermore, if the fascicles do not lie in 2D planes, then this has implications for architectural measures that are derived from 2D ultrasound scans. The purpose of this study was to quantify the 3D curvatures of the muscle fascicles and fascicle sheets within the triceps surae muscles and to test whether these curvatures varied among different contraction levels, muscle length, and regions within the muscle. Six male subjects were tested for three torque levels (0, 30, and 60% maximal voluntary contraction) and four ankle angles (−15, 0, 15, and 30° plantar flexion), and fascicles were imaged using 3D ultrasound techniques. The fascicle curvatures significantly increased at higher ankle torques and shorter muscle lengths. The fascicle sheet curvatures were of similar magnitude to the fascicle curvatures but did not vary between contractions. Fascicle curvatures were regionalized within each muscle with the curvature facing the deeper aponeuroses, and this indicates a greater intramuscular pressure in the deeper layers of muscles. Muscle architectural measures may be in error when using 2D images for complex geometries such as the soleus. PMID:25324510

Robust prediction of three-dimensional spinal curve from back surface for non-invasive follow-up of scoliosis

NASA Astrophysics Data System (ADS)

Bergeron, Charles; Labelle, Hubert; Ronsky, Janet; Zernicke, Ronald

2005-04-01

Spinal curvature progression in scoliosis patients is monitored from X-rays, and this serial exposure to harmful radiation increases the incidence of developing cancer. With the aim of reducing the invasiveness of follow-up, this study seeks to relate the three-dimensional external surface to the internal geometry, having assumed that that the physiological links between these are sufficiently regular across patients. A database was used of 194 quasi-simultaneous acquisitions of two X-rays and a 3D laser scan of the entire trunk. Data was processed to sets of datapoints representing the trunk surface and spinal curve. Functional data analyses were performed using generalized Fourier series using a Haar basis and functional minimum noise fractions. The resulting coefficients became inputs and outputs, respectively, to an array of support vector regression (SVR) machines. SVR parameters were set based on theoretical results, and cross-validation increased confidence in the system's performance. Predicted lateral and frontal views of the spinal curve from the back surface demonstrated average L2-errors of 6.13 and 4.38 millimetres, respectively, across the test set; these compared favourably with measurement error in data. This constitutes a first robust prediction of the 3D spinal curve from external data using learning techniques.

Magnetic curvature effects on plasma interchange turbulence

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

Li, B., E-mail: bli@pku.edu.cn; Liao, X.; Sun, C. K.

2016-06-15

The magnetic curvature effects on plasma interchange turbulence and transport in the Z-pinch and dipole-like systems are explored with two-fluid global simulations. By comparing the transport levels in the systems with a different magnetic curvature, we show that the interchange-mode driven transport strongly depends on the magnetic geometry. For the system with large magnetic curvature, the pressure and density profiles are strongly peaked in a marginally stable state and the nonlinear evolution of interchange modes produces the global convective cells in the azimuthal direction, which lead to the low level of turbulent convective transport.

Curvature-induced stiffening of a fish fin.

PubMed

Nguyen, Khoi; Yu, Ning; Bandi, Mahesh M; Venkadesan, Madhusudhan; Mandre, Shreyas

2017-05-01

How fish modulate their fin stiffness during locomotive manoeuvres remains unknown. We show that changing the fin's curvature modulates its stiffness. Modelling the fin as bendable bony rays held together by a membrane, we deduce that fin curvature is manifested as a misalignment of the principal bending axes between neighbouring rays. An external force causes neighbouring rays to bend and splay apart, and thus stretches the membrane. This coupling between bending the rays and stretching the membrane underlies the increase in stiffness. Using three-dimensional reconstruction of a mackerel ( Scomber japonicus ) pectoral fin for illustration, we calculate the range of stiffnesses this fin is expected to span by changing curvature. The three-dimensional reconstruction shows that, even in its geometrically flat state, a functional curvature is embedded within the fin microstructure owing to the morphology of individual rays. As the ability of a propulsive surface to transmit force to the surrounding fluid is limited by its stiffness, the fin curvature controls the coupling between the fish and its surrounding fluid. Thereby, our results provide mechanical underpinnings and morphological predictions for the hypothesis that the spanned range of fin stiffnesses correlates with the behaviour and the ecological niche of the fish. © 2017 The Author(s).

Curvature-induced stiffening of a fish fin

PubMed Central

2017-01-01

How fish modulate their fin stiffness during locomotive manoeuvres remains unknown. We show that changing the fin's curvature modulates its stiffness. Modelling the fin as bendable bony rays held together by a membrane, we deduce that fin curvature is manifested as a misalignment of the principal bending axes between neighbouring rays. An external force causes neighbouring rays to bend and splay apart, and thus stretches the membrane. This coupling between bending the rays and stretching the membrane underlies the increase in stiffness. Using three-dimensional reconstruction of a mackerel (Scomber japonicus) pectoral fin for illustration, we calculate the range of stiffnesses this fin is expected to span by changing curvature. The three-dimensional reconstruction shows that, even in its geometrically flat state, a functional curvature is embedded within the fin microstructure owing to the morphology of individual rays. As the ability of a propulsive surface to transmit force to the surrounding fluid is limited by its stiffness, the fin curvature controls the coupling between the fish and its surrounding fluid. Thereby, our results provide mechanical underpinnings and morphological predictions for the hypothesis that the spanned range of fin stiffnesses correlates with the behaviour and the ecological niche of the fish. PMID:28566508

Degenerative spinal disease in large felids.

PubMed

Kolmstetter, C; Munson, L; Ramsay, E C

2000-03-01

Degenerative spinal disorders, including intervertebral disc disease and spondylosis, seldom occur in domestic cats. In contrast, a retrospective study of 13 lions (Panthera leo), 16 tigers (Panthera tigris), 4 leopards (Panthera pardis), 1 snow leopard (Panthera uncia), and 3 jaguars (Panthera onca) from the Knoxville Zoo that died or were euthanatized from 1976 to 1996 indicated that degenerative spinal disease is an important problem in large nondomestic felids. The medical record, radiographic data, and the necropsy report of each animal were examined for evidence of intervertebral disc disease or spondylosis. Eight (three lions, four tigers, and one leopard) animals were diagnosed with degenerative spinal disease. Clinical signs included progressively decreased activity, moderate to severe rear limb muscle atrophy, chronic intermittent rear limb paresis, and ataxia. The age at onset of clinical signs was 10-19 yr (median = 18 yr). Radiographic evaluation of the spinal column was useful in assessing the severity of spinal lesions, and results were correlated with necropsy findings. Lesions were frequently multifocal, included intervertebral disc mineralization or herniation with collapsed intervertebral disc spaces, and were most common in the lumbar area but also involved cervical and thoracic vertebrae. Marked spondylosis was present in the cats with intervertebral disc disease, presumably subsequent to vertebral instability. Six of the animals' spinal cords were examined histologically, and five had acute or chronic damage to the spinal cord secondary to disc protrusion. Spinal disease should be suspected in geriatric large felids with decreased appetite or activity. Radiographic evaluation of the spinal column is the most useful method to assess the type and severity of spinal lesions.

Earthquake-related versus non-earthquake-related injuries in spinal injury patients: differentiation with multidetector computed tomography

PubMed Central

2010-01-01

Introduction In recent years, several massive earthquakes have occurred across the globe. Multidetector computed tomography (MDCT) is reliable in detecting spinal injuries. The purpose of this study was to compare the features of spinal injuries resulting from the Sichuan earthquake with those of non-earthquake-related spinal trauma using MDCT. Methods Features of spinal injuries of 223 Sichuan earthquake-exposed patients and 223 non-earthquake-related spinal injury patients were retrospectively compared using MDCT. The date of non-earthquake-related spinal injury patients was collected from 1 May 2009 to 22 July 2009 to avoid the confounding effects of seasonal activity and clothing. We focused on anatomic sites, injury types and neurologic deficits related to spinal injuries. Major injuries were classified according to the grid 3-3-3 scheme of the Magerl (AO) classification system. Results A total of 185 patients (82.96%) in the earthquake-exposed cohort experienced crush injuries. In the earthquake and control groups, 65 and 92 patients, respectively, had neurologic deficits. The anatomic distribution of these two cohorts was significantly different (P < 0.001). Cervical spinal injuries were more common in the control group (risk ratio (RR) = 2.12, P < 0.001), whereas lumbar spinal injuries were more common in the earthquake-related spinal injuries group (277 of 501 injured vertebrae; 55.29%). The major types of injuries were significantly different between these cohorts (P = 0.002). Magerl AO type A lesions composed most of the lesions seen in both of these cohorts. Type B lesions were more frequently seen in earthquake-related spinal injuries (RR = 1.27), while we observed type C lesions more frequently in subjects with non-earthquake-related spinal injuries (RR = 1.98, P = 0.0029). Conclusions Spinal injuries sustained in the Sichuan earthquake were located mainly in the lumbar spine, with a peak prevalence of type A lesions and a high occurrence of

Drug therapy in spinal tuberculosis.

PubMed

Rajasekaran, S; Khandelwal, Gaurav

2013-06-01

Although the discovery of effective anti-tuberculosis drugs has made uncomplicated spinal tuberculosis a medical disease, the advent of multi-drug-resistant Mycobacterium tuberculosis and the co-infection of HIV with tuberculosis have led to a resurgence of the disease recently. The principles of drug treatment of spinal tuberculosis are derived from our experience in treating pulmonary tuberculosis. Spinal tuberculosis is classified to be a severe form of extrapulmonary tuberculosis and hence is included in Category I of the WHO classification. The tuberculosis bacilli isolated from patients are of four different types with different growth kinetics and metabolic characteristics. Hence multiple drugs, which act on the different groups of the mycobacteria, are included in each anti-tuberculosis drug regimen. Prolonged and uninterrupted chemotherapy (which may be 'short course' and 'intermittent' but preferably 'directly observed') is effective in controlling the infection. Spinal Multi-drug-resistant TB and spinal TB in HIV-positive patients present unique problems in management and have much poorer prognosis. Failure of chemotherapy and emergence of drug resistance are frequent due to the failure of compliance hence all efforts must be made to improve patient compliance to the prescribed drug regimen.

Reliability and Validity of the TIMPSI for Infants With Spinal Muscular Atrophy Type I

PubMed Central

Krosschell, Kristin J.; Maczulski, Jo Anne; Scott, Charles; King, Wendy; Hartman, Jill T.; Case, Laura E.; Viazzo-Trussell, Donata; Wood, Janine; Roman, Carolyn A.; Hecker, Eva; Meffert, Marianne; Léveillé, Maude; Kienitz, Krista; Swoboda, Kathryn J.

2014-01-01

Purpose This study examined the reliability and validity of the Test of Infant Motor Performance Screening Items (TIMPSI) in infants with type I spinal muscular atrophy (SMA). Methods After training, 12 evaluators scored 4 videos of infants with type I SMA to assess interrater reliability. Intrarater and test-retest reliability was further assessed for 9 evaluators during a SMA type I clinical trial, with 9 evaluators testing a total of 38 infants twice. Relatedness of the TIMPSI score to ability to reach and ventilatory support was also examined. Results Excellent interrater video score reliability was noted (intraclass correlation coefficient, 0.97–0.98). Intrarater reliability was excellent (intraclass correlation coefficient, 0.91–0.98) and test-retest reliability ranged from r = 0.82 to r = 0.95. The TIMPSI score was related to the ability to reach (P ≤ .05). Conclusion The TIMPSI can reliably be used to assess motor function in infants with type I SMA. In addition, the TIMPSI scores are related to the ability to reach, an important functional skill in children with type I SMA. PMID:23542189

Impact of tube curvature on the ground-state magnetism of axially confined single-walled carbon nanotubes of the zigzag-type.

PubMed

Wu, Jianhua; Hagelberg, Frank

2013-06-03

The magnetic properties of axially confined, hydrogenated single-walled carbon nanotubes (SWCNTs) of the (n,0)-type with n=5-24 are systematically explored by density functional theory. Emphasis is placed on the relation between the ground-state magnetic moments of SWCNTs and zigzag graphene nanoribbons (ZGNRs). Comparison between the SWCNTs considered here and ZGNRs of equal length gives rise to two basic questions: 1) how does the nanotube curvature affect the antiferromagnetic order known to prevail for ZGNRs, and 2) to what extent do the magnetic moments localized at the SWCNT edges deviate from the zero-curvature limit of n/3μB ? In response to these questions, it is found that systems with n≥7 display preference for antiferromagnetic order at any length investigated, whereas for n=5, 6 the magnetic phase varies with tube length. Furthermore, elementary patterns are identified that describe the progression of the magnitude of the magnetic moment with n for the longest tubes explored in this work. The spin densities of the considered SWCNTs are analyzed as a function of the tube length L, with L ranging from 3 to 11 transpolyene rings for n≥7 and from 3 to 30 rings for n=5 and 6. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Computing Curvature Sensitivity of Biomolecules in Membranes by Simulated Buckling.

PubMed

Elías-Wolff, Federico; Lindén, Martin; Lyubartsev, Alexander P; Brandt, Erik G

2018-03-13

Membrane curvature sensing, where the binding free energies of membrane-associated molecules depend on the local membrane curvature, is a key factor to modulate and maintain the shape and organization of cell membranes. However, the microscopic mechanisms are not well understood, partly due to absence of efficient simulation methods. Here, we describe a method to compute the curvature dependence of the binding free energy of a membrane-associated probe molecule that interacts with a buckled membrane, which has been created by lateral compression of a flat bilayer patch. This buckling approach samples a wide range of curvatures in a single simulation, and anisotropic effects can be extracted from the orientation statistics. We develop an efficient and robust algorithm to extract the motion of the probe along the buckled membrane surface, and evaluate its numerical properties by extensive sampling of three coarse-grained model systems: local lipid density in a curved environment for single-component bilayers, curvature preferences of individual lipids in two-component membranes, and curvature sensing by a homotrimeric transmembrane protein. The method can be used to complement experimental data from curvature partition assays and provides additional insight into mesoscopic theories and molecular mechanisms for curvature sensing.

Types of neural cells in the spinal ganglia of human embryos and early fetuses.

PubMed

Olszewska, B; Woźniak, W; Gardner, E; O'Rahilly, R

1979-01-01

Spinal ganglial of human embryos and fetuses ranging in C.-R. length from 15 to 74 mm and in age from 6 1/2 to 11 postovulatory weeks were studied by light and electron microscopy. A sequence of events in differentiation and maturation enabled five types of cells to be distinguished: 1. apolar, undifferentiated neuroblasts are the main cells at 6 1/2 to 7 1/2 weeks; 2. early bipolar neuroblasts (strictly speaking, types 2 to 5 are immature neurons) predominate at the end of the embryonic period proper (8 postovulatory weeks); 3. intermediate bipolar neuroblasts are characteristic of the early fetal period; 4. late bipolar neuroblasts, in which two proceses arise separately from one pole of the cell, appear at about 10 postovulatory weeks; 5. unipolar neuroblasts are found within another week and, by that time, cells of types 1 and 2 are no longer present.

Biological and cognitive correlates of cortical curvature in schizophrenia.

PubMed

Lubeiro, Alba; de Luis-García, Rodrigo; Rodríguez, Margarita; Álvarez, Aldara; de la Red, Henar; Molina, Vicente

2017-10-27

Mean cortical curvature may relate to cortico-cortical connections integrity. We explored the association between prefrontal (PFC) cortical curvature and fractional anisotropy (FA) values for tracts connecting PFC and relevant cortical regions. In schizophrenia Anatomical and diffusion magnetic resonance images were obtained from 34 patients (16 of them first-episodes) and 32 healthy controls. We calculated curvature at rostral lateral prefrontal (RLPF) and superior medial prefrontal (SMPF) areas and mean FA for the tracts respectively connecting RLPF and SMPF areas with anterior caudal cingulate (ACC), superior temporal gyrus (STG) and superior parietal SP regions. Cognitive and clinical data were collected, including baseline symptoms, Clinical Global Impression change scores from baseline to follow-up, illness duration and treatment dosage. Patients showed significantly lower FA values in the tracts linking right RLPF-ACC, right SMPF-SPG and bilaterally PFC-STG. FA values in short-range cortico-cortical connections (linking PFC and ACC) were inversely associated with PFC curvature. In patients, cognitive performance was negatively associated with PFC curvature. Larger curvature values were associated to lack of clinical improvement at follow-up. We conclude that cortical curvature is influenced by integrity in short-range cortico-cortical connections and relates to cognition and clinical outcome in schizophrenia patients. Copyright © 2017 Elsevier B.V. All rights reserved.

Idiopathic Hypersomnia: A Study of 77 Cases

PubMed Central

Anderson, Kirstie N.; Pilsworth, Samantha; Sharples, Linda D.; Smith, Ian E.; Shneerson, John M.

2007-01-01

Study Objectives: To review the clinical and polysomnographic characteristics of idiopathic hypersomnia as well as the long-term response to treatment. Setting: The Respiratory Support and Sleep Centre at Papworth Hospital, Cambridge, UK. Patients and Design: A large database of more than 6000 patients with sleep disorders was reviewed. A retrospective study of the clinical and polysomnographic characteristics of 77 patients with idiopathic hypersomnia was performed. Comparison with a similar group of patients with narcolepsy was performed. The response to drug treatment was assessed in 61 patients over a mean follow-up of 3.8 years. Measurements and Results: Idiopathic hypersomnia was 60% as prevalent as narcolepsy. Comparison with a similar group of patients with narcolepsy showed that those with idiopathic hypersomnia were more likely to have prolonged unrefreshing daytime naps, a positive family history, increased slow-wave sleep, and a longer sleep latency on the Multiple Sleep Latency Test. The results of the Multiple Sleep Latency Test were not helpful in predicting disease severity or treatment response. The clinical features were heterogeneous and of variable severity. The majority of patients with idiopathic hypersomnia had symptoms that remained stable over many years, but 11% had spontaneous remission, which was never seen in narcolepsy. Two thirds of patients with idiopathic hypersomnolence had a sustained improvement in daytime somnolence with medication, although a third needed high doses or combinations of drugs. Conclusions: Idiopathic hypersomnolence has characteristic clinical and polysomnographic features but the prolonged latency on the Multiple Sleep Latency Test raises doubt about the validity of this test within the current diagnostic criteria. The disease often responds well to treatment and a substantial minority of patients appear to spontaneously improve. Citation: Anderson KN; Pilsworth S; Sharples LD; Smith IE; Shneerson JM. Idiopathic

Curvature-induced domain wall pinning

NASA Astrophysics Data System (ADS)

Yershov, Kostiantyn V.; Kravchuk, Volodymyr P.; Sheka, Denis D.; Gaididei, Yuri

2015-09-01

It is shown that a local bend of a nanowire is a source of pinning potential for a transversal head-to-head (tail-to-tail) domain wall. Eigenfrequency of the domain wall free oscillations at the pinning potential and the effective friction are determined as functions of the curvature and domain wall width. The pinning potential originates from the effective curvature-induced Dzyaloshinsky-like term in the exchange energy. The theoretical results are verified by means of micromagnetic simulations for the case of parabolic shape of the wire bend.

Congenital penile curvature: update and management.

PubMed

Makovey, Iryna; Higuchi, Ty T; Montague, Drogo K; Angermeier, Kenneth W; Wood, Hadley M

2012-08-01

Congenital penile curvature results from disproportionate development of the tunica albuginea of the corporal bodies and is not associated with urethral malformation. Patients usually present after reaching puberty as the curvature becomes more apparent with erections, and severe curvature can make intercourse difficult or impossible, at which point surgical repair is recommended. Excellent outcomes can be expected with surgical intervention. The three most commonly used repair techniques are the original Nesbit procedure, modified Nesbit procedure, and plication. Nesbit and modified Nesbit techniques require that an incision is made in the tunica albuginea while plication techniques utilize plicating sutures without an incision. While Nesbit and modified Nesbit techniques are more complex operations, these generally result in less recurrences and more satisfactory outcomes as opposed to the quicker and simpler plication technique.

Population pharmacokinetics of ϵ-aminocaproic acid in adolescents undergoing posterior spinal fusion surgery

PubMed Central

Stricker, P. A.; Gastonguay, M. R.; Singh, D.; Fiadjoe, J. E.; Sussman, E. M.; Pruitt, E. Y.; Goebel, T. K.; Zuppa, A. F.

2015-01-01

Background Despite demonstrated efficacy of ϵ-aminocaproic acid (EACA) in reducing blood loss in adolescents undergoing spinal fusion, there are no population-specific pharmacokinetic data to guide dosing. The aim of this study was to determine the pharmacokinetics of EACA in adolescents undergoing spinal fusion surgery and make dosing recommendations. Methods Twenty children ages 12–17 years were enrolled, with 10 children in each of two groups based on diagnosis (idiopathic scoliosis or non-idiopathic scoliosis). Previously reported data from infants undergoing craniofacial surgery were included in the model to enable dosing recommendations over a wide range of weights, ages, and diagnoses. A population non-linear mixed effects modelling approach was used to characterize EACA pharmacokinetics. Results Population pharmacokinetic parameters were estimated using a two-compartment disposition model with allometrically scaled weight and an age effect on clearance. Pharmacokinetic parameters for the typical patient were a plasma clearance of 153 ml min−1 70 kg−1 (6.32 ml min−1 kg−0.75), intercompartmental clearance of 200 ml min−1 70 kg−1 (8.26 ml min−1 kg−0.75), central volume of distribution of 8.78 litre 70 kg−1 (0.13 litre kg−1), and peripheral volume of distribution of 15.8 litre 70 kg−1 (0.23 litre kg−1). Scoliosis aetiology did not have a clinically significant effect on drug pharmacokinetics. Conclusions The following dosing schemes are recommended according to patient weight: weight <25 kg, 100 mg kg−1 loading dose and 40 mg kg−1 h−1 infusion; weight ≤25 kg–<50 kg, 100 mg kg−1 loading dose and 35 mg kg−1 h−1 infusion; and weight ≥50 kg, 100 mg kg−1 loading dose and 30 mg kg−1 h−1 infusion. An efficacy trial employing this dosing strategy is warranted. Clinical trial registration NCT01408823. PMID:25586726

Spin-curvature interaction from curved Dirac equation: Application to single-wall carbon nanotubes

NASA Astrophysics Data System (ADS)

Zhang, Kai; Zhang, Erhu; Chen, Huawei; Zhang, Shengli

2017-06-01

The spin-curvature interaction (SCI) and its effects are investigated based on curved Dirac equation. Through the low-energy approximation of curved Dirac equation, the Hamiltonian of SCI is obtained and depends on the geometry and spinor structure of manifold. We find that the curvature can be considered as field strength and couples with spin through Zeeman-like term. Then, we use dimension reduction to derive the local Hamiltonian of SCI for cylinder surface, which implies that the effective Hamiltonian of single-wall carbon nanotubes results from the geometry and spinor structure of lattice and includes two types of interactions: one does not break any symmetries of the lattice and only shifts the Dirac points for all nanotubes, while the other one does and opens the gaps except for armchair nanotubes. At last, analytical expressions of the band gaps and the shifts of their positions induced by curvature are given for metallic nanotubes. These results agree well with experiments and can be verified experimentally.

Aging and curvature discrimination from static and dynamic touch.