Article

Recovery of motor function after stroke may depend on a balance of
activity in the neural network involving the affected and the unaffected motor cortices.
OBJECTIVE: To assess whether Transcranial Direct Current Stimulation
(tDCS) can increase the training-induced recovery of motor functions. METHODS: In
an exploratory study, 14 patients with chronic stroke and mean Fugl-Meyer Upper
Extremity Motor Assessment of 29 (range = 8-50) entered a double-blind
sham-controlled study, aimed to investigate neurophysiological and behavioral
effects of bihemispheric tDCS (cathodal stimulation of the unaffected motor
cortex and anodal stimulation of the affected motor cortex), combined with
constraint-induced movement therapy (CIMT). RESULTS: Patients in both groups
demonstrated gains on primary outcome measures, that is, Jebsen Taylor Hand
Function Test, Handgrip Strength, Motor Activity Log Scale, and Fugl-Meyer Motor
Score. Gains were larger in the active tDCS group. Neurophysiological
measurements showed a reduction in transcallosal inhibition from the intact to
the affected hemisphere and increased corticospinal excitability in the affected
hemisphere only in the active tDCS/CIMT group. Such neurophysiological changes
correlated with the magnitude of the behavioral gains. Both groups showed a
reduction in corticospinal excitability of the unaffected hemisphere.
CONCLUSIONS: CIMT alone appears effective in modulating local excitability but
not in removing the imbalance in transcallosal inhibition. Bihemispheric tDCS may
achieve this goal and foster greater functional recovery.

Langue : ANGLAIS