Transcranial Direct Current Stimulation for the Treatment of Parkinson's Disease: Clinical and Regional Cerebral Blood Flow SPECT Outcomes.

BACKGROUND AND PURPOSE Over the course of treatment for Parkinson's disease (PD), the clinical effects of dopaminergic medication diminish and side effects emerge. Therefore, searching for new therapeutic alternatives or complementary treatments is required. Transcranial direct current stimulation (tDCS) could potentially complement the current therapeutic armamentarium, but only a few studies have investigated the therapeutic effects of tDCS in PD. The present pilot study aimed to investigate the effects of repeated tDCS treatment on motor symptoms and regional cerebral blood flow (rCBF) in patients with PD using single photon emission computed tomography (SPECT). METHODS Four patients with PD received tDCS to the dorsolateral prefrontal cortex two times per week (anode F3/cathode F4, 2 mA for 30 minutes) over a period of 12 months. Patients underwent brain SPECT scans and clinical motor evaluation at baseline and 12-month follow-up. For SPECT data, voxel-wise changes in rCBF were analyzed. RESULTS There was no significant change of the motor severity scale, but the follow-up SPECT showed significant hyperperfusion in the left superior frontal gyrus medial segment and left superior parietal lobule compared to baseline (P < .001). CONCLUSIONS This study shows that tDCS application may improve rCBF in the frontal and parietal lobes in patients with PD, suggesting beneficial effects of tDCS on brain function. Our results are preliminary and further large-scale studies are needed to confirm our findings.