Effects of successive repetitive transcranial magnetic stimulation on motor performances and brain perfusion in idiopathic Parkinson's disease

We studied the effects of 0.2 Hz repetitive transcranial magnetic stimulation (rTMS) successively performed 6 times for 2 weeks in 12 patients with idiopathic Parkinson's disease (PD). Ten patients received rTMS to the bilateral frontal cortex (frontal rTMS) and six patients received rTMS to the bilateral occipital cortex (occipital rTMS). Before and after rTMS, we evaluated regional cerebral blood flow (rCBF) using 99m-Tc-ECD single photon emission computed tomography (SPECT) and clinical tests.In an analysis with statistic parametric mapping, both frontal and occipital rTMS reduced rCBF in the cortical areas around the stimulated site. The activities of daily living (ADL) and motor scores of Unified Parkinson's Disease Rating Scale (UPDRS), pronation-supination movements, and buttoning up significantly improved after frontal rTMS than before it, while occipital rTMS had no significant effects in clinical tests.The findings of the present study suggest that successive 0.2 Hz rTMS has outlasting inhibitory effects on neuronal activity around the stimulated cortical areas. Because there were no significant relations between improved clinical tests and reduced rCBF, we speculate that the indirect effects of 0.2 Hz rTMS on subcortical structures are related to improved parkinsonian symptoms. Further studies recruiting large numbers of subjects are required to confirm the efficacy of 0.2 Hz rTMS on PD.