Article

In well-recovered stroke patients with preserved hand movement, motor dysfunction
relates to interhemispheric and intracortical inhibition in affected hand
muscles. In less fully recovered patients unable to move their hand, the neural
substrates of recovered arm movements, crucial for performance of daily living
tasks, are not well understood. Here, we evaluated interhemispheric and
intracortical inhibition in paretic arm muscles of patients with no recovery of
hand movement (n = 16, upper extremity Fugl-Meyer Assessment = 27.0 +/- 8.6). We
recorded silent periods (contralateral and ipsilateral) induced by transcranial
magnetic stimulation during voluntary isometric contraction of the paretic biceps
and triceps brachii muscles (correlates of intracortical and interhemispheric
inhibition, respectively) and investigated links between the silent periods and
motor recovery, an issue that has not been previously explored. We report that
interhemispheric inhibition, stronger in the paretic triceps than biceps brachii
muscles, significantly correlated with the magnitude of residual impairment
(lower Fugl-Meyer scores). In contrast, intracortical inhibition in the paretic
biceps brachii, but not in the triceps, correlated positively with motor recovery
(Fugl-Meyer scores) and negatively with spasticity (lower Modified Ashworth
scores). Our results suggest that interhemispheric inhibition and intracortical
inhibition of paretic upper arm muscles relate to motor recovery in different
ways. While interhemispheric inhibition may contribute to poorer recovery,
muscle-specific intracortical inhibition may relate to successful motor recovery
and lesser spasticity.
CI - (c) The Author(s) 2015.

Langue : ANGLAIS