TY - BOOK AU - Breceda, Erika Y AU - Chan, Evan AU - Dromerick, Alexander W AU - Harrington, Rachael AU - Harris-Love, Michelle TI - Role of contralesional hemisphere in paretic arm reaching in patients with severe arm paresis due to stroke: A preliminary report SN - 0304-3940 PY - 2016/// KW - *Arm/pp [Physiopathology] KW - *Motor Cortex/pp [Physiopathology] KW - *Paresis/pp [Physiopathology] KW - *Stroke/pp [Physiopathology] KW - Adult KW - Aged KW - Chronic Disease KW - Female KW - Humans KW - Male KW - Middle Aged KW - Movement KW - Paresis/et [Etiology] KW - Reaction Time KW - Stroke/co [Complications] KW - Transcranial Magnetic Stimulation KW - MedStar Washington Hospital Center KW - National Rehabilitation Network KW - Journal Article KW - Research Support, N.I.H., Extramural KW - Research Support, Non-U.S. Gov't N2 - 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 UR - http://dx.doi.org/10.1016/j.neulet.2016.02.004 ER -