Simultaneous repetitive transcranial magnetic stimulation does not speed fine movement in PD

Objective: To reevaluate the effect of subthreshold repetitive transcranial magnetic stimulation (rTMS) on concurrent fine movement in PD. Background: A previous study showed a beneficial effect of rTMS on the performance of six patients with PD on the Grooved Pegboard test. Methods: The authors repeated this experiment in 11 patients with idiopathic PD who performed the test while the stimulating coil discharged continuously at 5 Hz, either over the contralateral motor cortex at just below the threshold for movement, or in the air near the head as a control. Patients were tested twice under both conditions. Results: Although some patients performed faster with rTMS, others showed the opposite effect. There was no significant effect of rTMS in the group, nor did baseline performance or the order of conditions interact with the effect of rTMS. Conclusions: Based on this larger and more comprehensive study, simultaneous, 5-Hz subthreshold rTMS over the motor cortex does not have consistent or potentially therapeutic effects on movement in PD.