scholarly journals Limited Capacity for Ipsilateral Secondary Motor Areas to Support Hand Function Post-Stroke

2019 ◽  
Author(s):  
Kevin B. Wilkins ◽  
Jun Yao ◽  
Meriel Owen ◽  
Haleh Karbasforoushan ◽  
Carolina Carmona ◽  
...  
Keyword(s):  
Hand Function ◽  
Shoulder Abduction ◽  
Limited Capacity ◽  
Post Stroke ◽  
Backup System ◽  
Reticulospinal Tract ◽  
Hemiparetic Stroke ◽  
Chronic Hemiparetic Stroke ◽  
Hand Opening ◽  
Motor Areas

AbstractRecent findings have shown connections of ipsilateral cortico-reticulospinal tract (CRST), predominantly originating from secondary motor areas, to not only proximal but also distal portions of the arm. In unilateral stroke, CRST from the ipsilateral side is intact and thus has been proposed as a possible backup system for post-stroke rehabilitation even for the hand. We argue that although CRST from ipsilateral secondary motor areas can provide control for proximal joints, it is insufficient to control either hand or coordinated shoulder and hand movements due to its extensive branching compared to contralateral corticospinal tract. To address this issue, we combined MRI, high-density EEG, and robotics in 17 individuals with severe chronic hemiparetic stroke and 12 age-matched controls. We tested for changes in structural morphometry of the sensorimotor cortex and found that individuals with stroke demonstrated higher gray matter density in secondary motor areas ipsilateral to the paretic arm compared to controls. We then measured cortical activity while participants attempted to generate hand opening either supported on a table or while lifting against a shoulder abduction load. The addition of shoulder abduction during hand opening increased reliance on ipsilateral secondary motor areas in stroke, but not controls. Crucially, increased use of ipsilateral secondary motor areas was associated with decreased hand opening ability while lifting the arm due to involuntary coupling between the shoulder and wrist/finger flexors. Together, this evidence implicates a compensatory role for ipsilateral (i.e., contralesional) secondary motor areas post-stroke, but with limited capacity to support hand function.

scholarly journals Limited capacity for ipsilateral secondary motor areas to support hand function post‐stroke

2020 ◽  
Vol 598 (11) ◽  
pp. 2153-2167 ◽  
Author(s):  
Kevin B. Wilkins ◽  
Jun Yao ◽  
Meriel Owen ◽  
Haleh Karbasforoushan ◽  
Carolina Carmona ◽  
...  
Keyword(s):  
Hand Function ◽  
Limited Capacity ◽  
Post Stroke ◽  
Motor Areas

scholarly journals Effects of Altered Neural Input and Botulinum Toxin on Finger and Wrist Passive Properties in Chronic Hemiparetic Stroke

2019 ◽  
Author(s):  
Benjamin I Binder-Markey ◽  
Wendy M Murray ◽  
Julius P.A. Dewald
Keyword(s):  
Hand Function ◽  
Biomechanical Properties ◽  
Optimal Recovery ◽  
Motor Impairments ◽  
Sleep State ◽  
Post Stroke ◽  
Neural Input ◽  
Hemiparetic Stroke ◽  
Chronic Hemiparetic Stroke

ABSTRACTBackground and PurposeFollowing a hemiparetic stroke, prolonged altered motor neuron inputs may drive passive mechanical changes within muscle that further amplify brain injury induced motor impairments, reducing optimal recovery. However, due to confounding factors, i.e. muscle hypertonicity and spasticity, and the use of botulinum neurotoxin (BoNT), chemical denervation to reduce their expression, there is no consensus on how altered neural inputs following a stroke affect muscle passive mechanical properties or the extent to which these properties ultimately limit functional recovery. Therefore, the objective of this study is to quantify muscle passive biomechanical properties following chronic hemiparetic stroke and BoNT.MethodsPassive torques about the wrist and metacarpophalangeal (MCP) joints were quantified in both hands of 34 individuals with chronic hemiparetic stroke. Participants’ hand impairments ranged from severe to mild with a subset who previously received BoNT injections. Torques were quantified with subjects in a sleep or near-sleep state, mitigating muscle hyperactivity. EMGs were continuously monitored to ensure no muscle activity during data collection.ResultsParticipants who previously received BoNT injections demonstrated significantly greater passive flexion torques about their paretic wrist and fingers as compared to those who never received BoNT. As a result, only the group who received BoNT demonstrated significant decreases in passive MCP extension.ConclusionsThe results of our thorough investigation of in vivo passive elastic torques at the wrist and fingers in chronic hemiparetic stroke contrast with the increased stiffness and decreased passive ROM observed clinically and in many previous studies. We highlight the need to effective address both stroke-induced muscle hyperactivity and BoNT treatment history as confounds. We conclude that loss of hand function post-stroke is predominantly due to motor impairments post stroke. Adverse effects of BoNT warrant consideration in future studies and rehabilitation interventions.

scholarly journals The Impact of Shoulder Abduction Loading on Volitional Hand Opening and Grasping in Chronic Hemiparetic Stroke

2017 ◽  
Vol 31 (6) ◽  
pp. 521-529 ◽  
Author(s):  
Yiyun Lan ◽  
Jun Yao ◽  
Julius P. A. Dewald
Keyword(s):  
Shoulder Abduction ◽  
Grasping Forces ◽  
Finger Flexion ◽  
Enhanced Expression ◽  
Hemiparetic Stroke ◽  
Chronic Hemiparetic Stroke ◽  
And Control ◽  
The Impact ◽  
Hand Opening ◽  
Flexion Synergy

Background. Up to 60% of individuals with moderate to severe chronic hemiparetic stroke experience excessive involuntary wrist/finger flexion that constrains functional hand movements including hand opening. It’s not known how stroke-induced brain injury impacts volitional hand opening and grasping forces as a result of the expression of abnormal coupling between shoulder abduction and wrist/finger flexion or the flexion synergy. Objective. The goal of this study is to understand how shoulder abduction loading affects volitional hand opening and grasping forces in individuals with moderate to severe chronic hemiparetic stroke. Methods. Thirty-six individuals (stroke, 26; control, 10) were recruited for this study. Each participant was instructed to perform maximal hand opening and grasping forces while the arm was either fully supported or lifted with a weight equal to 25% or 50% of the participant’s maximal shoulder abduction torque. Hand pentagon area, defined as the area formed by the tips of thumb and fingers, was calculated during hand opening. Forces were recorded during grasping. Results. In individuals with moderate stroke, increasing shoulder abduction loading reduced the ability to maximally open the hand. In individuals with severe stroke, who were not able to open the hand, grasping forces were generated and increased with shoulder abduction loading. Stroke individuals also showed a reduced ability to control volitional grasping forces due to the enhanced expression of flexion synergy. Conclusions. Shoulder abduction loading reduced the ability to volitionally open the hand and control grasping forces after stroke. Neural mechanisms and clinical implications of these findings are discussed.

scholarly journals Intervention-Induced Changes in Cortical Connectivity and Activity in Severe Chronic Hemiparetic Stroke

2019 ◽  
Author(s):  
Kevin B. Wilkins ◽  
Julius P.A. Dewald ◽  
Jun Yao
Keyword(s):  
Sensorimotor Cortex ◽  
Hand Function ◽  
Cortical Activity ◽  
Chronic Stroke ◽  
Movement Preparation ◽  
Movement Execution ◽  
Post Intervention ◽  
Primary Sensorimotor Cortex ◽  
Hemiparetic Stroke ◽  
Hand Opening

AbstractObjectiveEffective interventions have demonstrated the ability to improve motor function by reengaging ipsilesional resources, which has been shown to be critical and feasible for hand function recovery even in individuals with severe chronic stroke. However, the question remains how these focal activity changes (i.e., changes in activity within motor regions) relate to altered cortico-cortico interactions within/across multiple regions.MethodsEight individuals with severe chronic stroke participated in a device-assisted intervention. Pre- and post-intervention, we collected EEG while performing hand opening with/without lifting the paretic arm. We quantified changes in focal cortical activity at movement execution and connectivity during movement preparation.ResultsPost-intervention, individuals displayed a reduction in coupling from ipsilesional M1 to contralesional M1 within gamma frequencies during movement preparation for hand opening. This was followed by a reduction in activity in contralesional primary sensorimotor cortex during movement execution. Meanwhile, during lifting and opening, a more inhibitory coupling within ipsilesional M1 from gamma to beta frequencies was accompanied by an increase in ipsilesional primary sensorimotor cortex activity.ConclusionsChanges in coupling within or between motor regions during movement preparation complement topographical activity changes at movement execution.SignificanceOur results suggest that changes in cortico-cortico interactions may lead to corresponding changes in focal cortical activity.

Traumatic Brachial Plexus Palsy in Children: Long-Term Outcome and Strategy of Reconstruction

2021 ◽  
Author(s):  
Tarek A. El-Gammal ◽  
Amr El-Sayed ◽  
Mohamed M. Kotb ◽  
Waleed Riad Saleh ◽  
Yasser Farouk Ragheb ◽  
...  
Keyword(s):  
Brachial Plexus ◽  
External Rotation ◽  
Hand Function ◽  
Functional Restoration ◽  
Shoulder Abduction ◽  
Wrist Flexion ◽  
Term Outcome ◽  
Long Term Outcome ◽  
Age At Surgery ◽  
Flexion And Extension

Abstract Background Traumatic brachial plexus injuries in children represent a definite spectrum of injuries between adult and neonatal brachial plexus injuries. Their characteristics have been scarcely reported in the literature. The priority of functional restoration is not clear. Materials and Methods In total, 52 children with surgically treated traumatic brachial plexus injuries, excluding Erb's palsy, were reviewed after a minimum follow-up of 2 years. All children except nine were males, with an average age at surgery of 8 years. Forty-five children had exclusive supraclavicular plexus injuries. Twenty-one of them (46%) had two or more root avulsions. Seven children (13.5%) had infraclavicular plexus injuries. Time from trauma to surgery varied from 1 to 15 months (mean = 4.7 months). Extraplexal neurotization was the most common surgical technique used. Results Shoulder abduction and external rotation were restored to an average of 83 and 26 degrees, respectively. Elbow flexion and extension were restored to grade ≥3 in 96 and 91.5% of cases, respectively. Finger flexion and extension were restored to grade ≥4 in 29 and 32% of cases, respectively. Wrist flexion and extension were restored to grade ≥4 in 21 and 27% of cases, respectively. Results of neurotization were superior to those of neurolysis and nerve grafting. Among the 24 children with insensate hands, 20 (83.3%) recovered S3 sensation, 3 recovered S2, and 1 recovered S1. No case complained of neuropathic pain. Functional recovery correlated negatively but insignificantly with the age at surgery and time from injury to surgery. Conclusion Brachial plexus injuries in children are associated with a high incidence root avulsions and no pain. Neurotization is frequently required and the outcome is not significantly affected by the delay in surgery. In total plexus injuries, some useful hand function can be restored, and management should follow that of obstetric palsy and be focused on innervating the medial cord.

The NIH Stroke Scale Lacks Validity in Chronic Hemiparetic Stroke

2015 ◽  
Vol 96 (10) ◽  
pp. e35
Author(s):  
Heather Tanksley Peters ◽  
Susan White ◽  
Stephen Page
Keyword(s):  
Hemiparetic Stroke ◽  
Chronic Hemiparetic Stroke
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