Medicine and Health Sciences Commons^™

Different Biomechanical Variables Explain Within-Subjects Versus Between-Subjects Variance In Step Length Asymmetry Post-Stroke, Natalia Sánchez, Nicolas Schweighofer, James M. Finley

Physical Therapy Faculty Articles and Research

Step length asymmetry (SLA) is common in most stroke survivors. Several studies have shown that factors such as paretic propulsion can explain between-subjects differences in SLA. However, whether the factors that account for between-subjects variance in SLA are consistent with those that account for within subjects, stride-by-stride variance in SLA has not been determined. SLA direction is heterogeneous, and different impairments likely contribute to differences in SLA direction. Here, we identified common predictors between-subjects that explain within-subjects variance in SLA using sparse partial least squares regression (sPLSR). We determined whether the SLA predictors differ based on SLA direction and whether …

Using Biofeedback To Reduce Spatiotemporal Asymmetry Impairs Dynamic Balance In People Post-Stroke, Sungwoo Park, Chang Liu, Natalia Sánchez, Julie K. Tilson, Sara J. Mulroy, James M. Finley

Physical Therapy Faculty Articles and Research

Background. People poststroke often walk with a spatiotemporally asymmetric gait, due in part to sensorimotor impairments in the paretic lower extremity. Although reducing asymmetry is a common objective of rehabilitation, the effects of improving symmetry on balance are yet to be determined. Objective. We established the concurrent validity of whole-body angular momentum as a measure of balance, and we determined if reducing step length asymmetry would improve balance by decreasing whole-body angular momentum. Methods. We performed clinical balance assessments and measured wholebody angular momentum during walking using a full-body marker set in a sample of 36 people with …

Explicit Training To Improve Affective Prosody Recognition In Adults With Acute Right Hemisphere Stroke, Alexandra Zezinka Durfee, Shannon M. Sheppard, Erin L. Meier, Lisa Bunker, Erjia Cui, Ciprian Crainiceanu, Argye E. Hillis

Communication Sciences and Disorders Faculty Articles and Research

Difficulty recognizing affective prosody (receptive aprosodia) can occur following right hemisphere damage (RHD). Not all individuals spontaneously recover their ability to recognize affective prosody, warranting behavioral intervention. However, there is a dearth of evidence-based receptive aprosodia treatment research in this clinical population. The purpose of the current study was to investigate an explicit training protocol targeting affective prosody recognition in adults with RHD and receptive aprosodia. Eighteen adults with receptive aprosodia due to acute RHD completed affective prosody recognition before and after a short training session that targeted proposed underlying perceptual and conceptual processes. Behavioral impairment and lesion characteristics were …

Lost In Translation: Simple Steps In Experimental Design Of Neurorehabilitation-Based Research Interventions To Promote Motor Recovery Post-Stroke, Natalia Sánchez, Carolee J. Winstein

Physical Therapy Faculty Articles and Research

Stroke continues to be a leading cause of disability. Basic neurorehabilitation research is necessary to inform the neuropathophysiology of impaired motor control, and to develop targeted interventions with potential to remediate disability post-stroke. Despite knowledge gained from basic research studies, the effectiveness of researchbased interventions for reducing motor impairment has been no greater than standard of practice interventions. In this perspective, we offer suggestions for overcoming translational barriers integral to experimental design, to augment traditional protocols, and re-route the rehabilitation trajectory toward recovery and away from compensation. First, we suggest that researchers consider modifying task practice schedules to focus on …

Diagnosing And Managing Post-Stroke Aphasia, Shannon M. Sheppard, Rajani Sebastian

Communication Sciences and Disorders Faculty Articles and Research

Introduction: Aphasia is a debilitating language disorder and even mild forms of aphasia can negatively affect functional outcomes, mood, quality of life, social participation, and the ability to return to work. Language deficits after post-stroke aphasia are heterogeneous.

Areas covered: The first part of this manuscript reviews the traditional syndrome-based classification approach as well as recent advances in aphasia classification that incorporate automatic speech recognition for aphasia classification. The second part of this manuscript reviews the behavioral approaches to aphasia treatment and recent advances such as noninvasive brain stimulation techniques and pharmacotherapy options to augment the effectiveness of …

Role Of Neuronal Nitric Oxide Synthase On Cardiovascular Functions In Physiological And Pathophysiological States, Ahmmed Ally, Isabella Powell, Minora M. Ally, Kevin Chaitoff, Surya M. Nauli

Pharmacy Faculty Articles and Research

This review describes and summarizes the role of neuronal nitric oxide synthase (nNOS) on the central nervous system, particularly on brain regions such as the ventrolateral medulla (VLM) and the periaqueductal gray matter (PAG), and on blood vessels and the heart that are involved in the regulation and control of the cardiovascular system (CVS). Furthermore, we shall also review the functional aspects of nNOS during several physiological, pathophysiological, and clinical conditions such as exercise, pain, cerebral vascular accidents or stroke and hypertension. For example, during stroke, a cascade of molecular, neurochemical, and cellular changes occur that affect the nervous system …

Predicting Gains With Visuospatial Training After Stroke Using An Eeg Measure Of Frontoparietal Circuit Function, Robert J. Zhou, Hossein M. Hondori, Maryam Khademi, Jessica M. Cassidy, Katherine M. Wu, Derek Z. Yang, Nikhita Kathuria, Fareshte R. Erani, Lucy Dodakian, Alison Mckenzie, Cristina V. Lopes, Walt Scacchi, Ramesh Srinivasan, Steven C. Cramer

Physical Therapy Faculty Articles and Research

The heterogeneity of stroke prompts the need for predictors of individual treatment response to rehabilitation therapies. We previously studied healthy subjects with EEG and identified a frontoparietal circuit in which activity predicted training-related gains in visuomotor tracking. Here we asked whether activity in this same frontoparietal circuit also predicts training-related gains in visuomotor tracking in patients with chronic hemiparetic stroke. Subjects (n = 12) underwent dense-array EEG recording at rest, then received 8 sessions of visuomotor tracking training delivered via home-based telehealth methods. Subjects showed significant training-related gains in the primary behavioral endpoint, Success Rate score on a standardized test …

Neural Constraints Affect The Ability To Generate Hip Abduction Torques When Combined With Hip Extension Or Ankle Plantarflexion In Chronic Hemiparetic Stroke, Natalia Sánchez, Ana M. Acosta, Roberto López-Rosado, Julius P. A. Dewald

Physical Therapy Faculty Articles and Research

Stroke lesions interrupt descending corticofugal fibers that provide the volitional control of the upper and lower extremities. Despite the evident manifestation of movement impairments post-stroke during standing and gait, neural constraints in the ability to generate joint torque combinations in the lower extremities are not yet well determined. Twelve chronic hemiparetic participants and 8 age-matched control individuals participated in the present study. In an isometric setup, participants were instructed to combine submaximal hip extension or ankle plantarflexion torques with maximal hip abduction torques. Statistical analyses were run using linear mixed effects models. Results for the protocol combining hip extension and …

Lower Extremity Motor Impairments In Ambulatory Chronic Hemiparetic Stroke: Evidence For Lower Extremity Weakness And Abnormal Muscle And Joint Torque Coupling Patterns, Natalia Sánchez, Ana Maria Acosta, Roberto Lopez-Rosado, Arno H. A. Stienen, Julius P. A. Dewald

Physical Therapy Faculty Articles and Research

Although global movement abnormalities in the lower extremity poststroke have been studied, the expression of specific motor impairments such as weakness and abnormal muscle and joint torque coupling patterns have received less attention. We characterized changes in strength, muscle coactivation and associated joint torque couples in the paretic and nonparetic extremity of 15 participants with chronic poststroke hemiparesis (age 59.6 ± 15.2 years) compared with 8 age-matched controls. Participants performed isometric maximum torques in hip abduction, adduction, flexion and extension, knee flexion and extension, ankle dorsi- and plantarflexion and submaximal torques in hip extension and ankle plantarflexion. Surface electromyograms (EMGs) …

Role Of Corpus Callosum Integrity In Arm Function Differs Based On Motor Severity After Stroke, Jill Campbell Stewart, Pritha Dewanjee, George Tran, Erin Burke Quinlan, Lucy Dodakian, Alison Mckenzie, Jill See, Steven C. Cramer

Physical Therapy Faculty Articles and Research

While the corpus callosum (CC) is important to normal sensorimotor function, its role in motor function after stroke is less well understood. This study examined the relationship between structural integrity of the motor and sensory sections of the CC, as reflected by fractional anisotropy (FA), and motor function in individuals with a range of motor impairment level due to stroke. Fifty-five individuals with chronic stroke (Fugl-Meyer motor score range 14 to 61) and 18 healthy controls underwent diffusion tensor imaging and a set of motor behavior tests. Mean FA from the motor and sensory regions of the CC and from …

1st Place Research Paper: The Effectiveness Of Yoga Therapy On An Adult, Post-Stroke Population: A Systematic Review, Baylor E. Hogan

Kevin and Tam Ross Undergraduate Research Prize

Objectives: The objectives of this paper are to (1) give a brief overview of stroke pathophysiology (2) outline yoga as a therapeutic strategy (3) present the current research on yoga rehabilitation for stroke (4) discuss the efficacy of yoga for chronic stroke.

Methods: Relevant terms were searched in PubMed, Web of Science, Academic OneFile, ScienceDirect, and Google Scholar electronic databases. Studies were excluded if they contained pediatric stroke, non-stroke neurological diseases, or subjects with comorbidities. Statistically significant data was extracted for the primary measures of nine trials.

Results: Four studies measured statistically significant outcomes (p<0.05). These included improvements in balance, independence, endurance, trait anxiety, fear of falling, self-efficacy, pain, strength, range of motion (ROM), activity, participation, and quality of life (QoL). Discussion: Lack of statistical significance in post-stroke depression (PSD) measures may be due to inadequate intervention length or a psychosocial cause of depression. Improvements in balance, flexibility, and strength from yoga participation permitted progress in disability and functionality. Finally, overall health-related quality of life (HRQL) is affected by the severity of mental disorders and physical disability. Yoga can have a positive effect in both domains and therefore, may improve HRQL.

Conclusion: …

1st Place Contest Entry: The Effectiveness Of Yoga Therapy On An Adult, Post-Stroke Population: A Systematic Review, Baylor E. Hogan

Kevin and Tam Ross Undergraduate Research Prize

This is Baylor Hogan's submission for the 2016 Kevin and Tam Ross Undergraduate Research Prize, which won first place. She wrote about the effects of yoga therapy on the physical and mental wellbeing of stroke patients. You can read the final essay that came out of her research here.

Baylor is a senior at Chapman University, majoring in Kinesiology. Her faculty mentor is Dr. Elizabeth DeBaets.

Connectivity Measures Are Robust Biomarkers Of Cortical Function And Plasticity After Stroke, Jennifer Wu, Erin Burke Quinlan, Lucy Dodakian, Alison Mckenzie, Nikhita Kathuria, Robert J. Zhou, Renee Augsburger, Jill See, Vu H. Lee, Ramesh Srinivasan, Steven C. Cramer

Physical Therapy Faculty Articles and Research

Valid biomarkers of motor system function after stroke could improve clinical decision-making. Electroencephalography-based measures are safe, inexpensive, and accessible in complex medical settings and so are attractive candidates. This study examined specific electroencephalography cortical connectivity measures as biomarkers by assessing their relationship with motor deficits across 28 days of intensive therapy. Resting-state connectivity measures were acquired four times using dense array (256 leads) electroencephalography in 12 hemiparetic patients (7.3 ± 4.0 months post-stroke, age 26–75 years, six male/six female) across 28 days of intensive therapy targeting arm motor deficits. Structural magnetic resonance imaging measured corticospinal tract injury and infarct volume. …

Neuroprotective Effects Of Bilobalide Are Accompanied By A Reduction Of Ischemia-Induced Glutamate Release In Vivo, Dorothee Lang, Cornelia Kiewert, Alexander Mdzinarishvili, Tina Maria Schwarzkopf, Rachita K. Sumbria, Joachim Hartmann, Jochen Klein

Pharmacy Faculty Articles and Research

Neuroprotective properties of bilobalide, a specific constituent of Ginkgo extracts, were tested in a mouse model of stroke. After 24 h of middle cerebral artery occlusion (MCAO), bilobalide reduced infarct areas in the core region (striatum) by 40–50% when given at 10 mg/kg 1 h prior to MCAO. Neuroprotection was also observed at lower doses, or when the drug was given 1 h past stroke induction. Sensorimotor function in mice was improved by bilobalide as shown by corner and chimney tests. When brain metabolism in situ was monitored by microdialysis, MCAO caused a rapid disappearance of extracellular glucose in the …