Article

OBJECTIVE: To explore whether stroke patients exhibit increases in motor
excitability during action observation, whether differences exist between the
affected and non-affected sides, and between pure motor strokes and predominantly
sensory strokes. METHODS: In 18 patients (10 pure motor strokes, 8 predominantly
sensory strokes, < 6 months after the stroke) transcranial magnetic stimulation
was used to test motor excitability while the patients viewed a video showing a
hand performing pinch grips. Transcranial magnetic stimulation pulses were
applied at 120% of the individual motor threshold at rest, as obtained from the
affected hemisphere. Recordings were taken simultaneously from the first dorsal
interosseous muscle of both hands. Motor performance was evaluated with the Box
and Block Test. RESULTS: Transcranial magnetic stimulation-evoked muscle
responses obtained from the affected and the unaffected sides were significantly
higher during action observation than during rest (p = 0.024 and p = 0.004,
respectively). This effect was significantly stronger when measuring the same
hand as the one viewed in the video (p = 0.019). No difference was found between
motor and sensory strokes. In 11 patients there was an action
observation-associated increase in the amplitudes of motor evoked potentials in
the affected side. In 15 patients there was an action observation-associated
increase in motor evoked potentials amplitudes in the unaffected side.
CONCLUSION: The results are potentially relevant for the use of action
observation as a treatment strategy.

Langue : ANGLAIS