MedStar Authors catalog › Details for: Role of contralesional hemisphere in paretic arm reaching in patients with severe arm paresis due to stroke: A preliminary report.
Role of contralesional hemisphere in paretic arm reaching in patients with severe arm paresis due to stroke: A preliminary report. Journal: Neuroscience letters.Published: 2016ISSN: 0304-3940.UI/PMID: 26872851.Subject(s): Adult | Aged | *Arm/pp [Physiopathology] | Chronic Disease | Female | Humans | Male | Middle Aged | *Motor Cortex/pp [Physiopathology] | Movement | Paresis/et [Etiology] | *Paresis/pp [Physiopathology] | Reaction Time | Stroke/co [Complications] | *Stroke/pp [Physiopathology] | Transcranial Magnetic StimulationInstitution(s): MedStar Washington Hospital CenterDepartment(s): National Rehabilitation NetworkActivity type: Journal Article.Medline article type(s): Journal Article | Research Support, N.I.H., Extramural | Research Support, Non-U.S. Gov'tDigital Object Identifier: http://dx.doi.org/10.1016/j.neulet.2016.02.004 (Click here) Abbreviated citation: Neurosci Lett. 617:52-8, 2016 Mar 23.Abstract: Stroke is highly prevalent and a leading cause of serious, long-term disability among American adults. Impaired movement (i.e. paresis) of the stroke-affected arm is a major contributor to post-stroke disability, yet the mechanisms of upper extremity motor recovery are poorly understood, particularly in severely impaired patients who lack hand function. To address this problem, we examined the functional relevance of the contralesional hemisphere in paretic arm motor performance in individuals with severe arm paresis. Twelve individuals with severe stroke-induced arm paresis (Upper Extremity Fugl-Meyer Assessment=17.1 +/- 8.5; maximum score=66) participated in the study. Participants performed a reaching response time task with their paretic arm. At varying time intervals following a 'Go' cue, a pair of transcranial magnetic stimulation (TMS) pulses were delivered to contralesional hemisphere primary motor (M1) or dorsal pre-motor cortex (PMd) to momentarily disrupt the pattern of neural firing. Response time components and hand-path characteristics were compared across the 2 sites for trials with and without TMS disruption. There was no significant effect of TMS disruption on overall Response time or Reaction time, but Movement time was significantly longer (i.e. slower) with disruption of the contralesional hemisphere (p=0.015), regardless of which area was stimulated. Peak hand-path velocity and hand-path smoothness were also significantly lower (p=0.005 and p<0.0001, respectively) with TMS disruption of the contralesional hemisphere. The data from this study provide evidence supporting a functionally relevant role of contralesional hemisphere motor areas in paretic arm reaching movements in individuals with severe post-stroke arm impairment.Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.