Article

OBJECTIVE: To determine whether nonparetic arm force overinhibits the paretic arm
in patients with chronic unilateral poststroke hemiparesis. DESIGN: Case-control
neurophysiological and behavioral study of patients with chronic stroke. SETTING:
Research institution. PARTICIPANTS: Eighty-six referred patients were screened to
enroll 9 participants (N=9) with a >6 month history of 1 unilateral ischemic
infarct that resulted in arm hemiparesis with residual ability to produce 1Nm of
wrist flexion torque and without contraindication to transcranial magnetic
stimulation. Eight age- and handedness-matched healthy volunteers without
neurologic diagnosis were studied for comparison. INTERVENTIONS: Not applicable.
MAIN OUTCOME MEASURE: Change in interhemispheric inhibition targeting the
ipsilesional primary motor cortex (M1) during nonparetic arm force. We
hypothesized that interhemispheric inhibition would increase more in healthy
controls than in patients with hemiparesis. RESULTS: Healthy age-matched controls
had significantly greater increases in inhibition from their active to resting M1
than patients with stroke from their active contralesional to resting
ipsilesional M1 in the same scenario (20%+/-7% vs -1%+/-4%, F1,12=6.61, P=.025).
Patients with greater increases in contralesional to ipsilesional inhibition were
better performers on the 9-hole peg test of paretic arm function. CONCLUSIONS:
Our findings reveal that producing force with the nonparetic arm does not
necessarily overinhibit the paretic arm. Though our study is limited in
generalizability by the small sample size, we found that greater active
contralesional to resting ipsilesional M1 inhibition was related with better
recovery in this subset of patients with chronic poststroke.
CI - Copyright (c) 2014 American Congress of Rehabilitation Medicine. Published by
Elsevier Inc. All rights reserved.

Langue : ANGLAIS