Repetitive transcranial magnetic stimulation over bilateral hemispheres enhances motor function and training effect of paretic hand in patients after stroke

OBJECTIVE: The interhemispheric competition model proposes that the functional recovery of motor deficits in patients after stroke can be achieved by increasing the excitability of the affected hemisphere or decreasing the excitability of the unaffected hemisphere. We investigated whether bilateral repetitive transcranial magnetic stimulation might improve the paretic hand in patients after stroke. DESIGN: A double-blind study. PATIENTS: Thirty patients with chronic subcortical stroke. METHODS: The patients were randomly assigned to receive 1 Hz repetitive transcranial magnetic stimulation over the unaffected hemisphere, 10 Hz repetitive transcranial magnetic stimulation over the affected hemisphere, or bilateral repetitive transcranial magnetic stimulation comprising both the 1 Hz and 10 Hz repetitive transcranial magnetic stimulation. All patients underwent motor training following repetitive transcranial magnetic stimulation. RESULTS: Bilateral repetitive transcranial magnetic stimulation and 1 Hz repetitive transcranial magnetic stimulation immediately improved acceleration in the paretic hand. Compared with 1 Hz repetitive transcranial magnetic stimulation, bilateral repetitive transcranial magnetic stimulation decreased the inhibitory function of the affected motor cortex and enhanced the effect of motor training on pinch force. Moreover, this effect of motor training lasted for one week. On the other hand, 10 Hz repetitive transcranial magnetic stimulation had no effect on the motor function. CONCLUSION: Bilateral repetitive transcranial magnetic stimulation improved the motor training effect on the paretic hand of patients after stroke more than unilateral stimulation in pinch force; this might indicate a new neurorehabilitative strategy for stroke.