Article

Action observation has been suggested as a possible gateway to
retraining arm motor function post stroke. However, it is unclear if the neuronal
response to action observation is affected by stroke and if it changes during the
course of recovery. OBJECTIVE: To examine longitudinal changes in neuronal
activity in a group of patients with subacute stroke when observing and executing
a bimanual movement task. METHODS: Eighteen patients were examined twice using
3-T functional magnetic resonance imaging; 1 to 2 weeks and 3 months post stroke
symptom onset. Eighteen control participants were examined once. Image time
series were analyzed (SPM8) and correlated with clinical motor function scores.
RESULTS: During action observation and execution, an overlap of neuronal
activation was observed in the superior and inferior parietal lobe, precentral
gyrus, insula, and inferior temporal gyrus in both control participants and
patients (P < .05; false discovery rate corrected). The neuronal response in the
observation task increased from 1 to 2 weeks to 3 months after stroke. Most
activated clusters were observed in the inferior temporal gyrus, the thalamus and
movement-related areas, such as the premotor, supplementary and motor cortex
(BA4, BA6). Increased activation of cerebellum and premotor area correlated with
improved arm motor function. Most patients had regained full movement ability.
CONCLUSIONS: Plastic changes in neurons responding to action observation and
action execution occurred in accordance with clinical recovery. The involvement
of motor areas when observing actions early and later after stroke may constitute
a possible access to the motor system.
CI - (c) The Author(s) 2014.

Langue : ANGLAIS