Transcranial direct current stimulation for treatment of freezing of gait: a cross-over study.

BACKGROUND AND OBJECTIVE: Progression of Parkinson's disease (PD) is frequently characterized by the occurrence of freezing of gait (FOG) representing a disabling motor complication. We aim to investigate safety and efficacy of transcranial direct current stimulation of the primary motor cortex of PD patients with FOG. METHODS: In this cross-over, double-blind, sham-controlled study, 10 PD patients with FOG persisting in "on" state underwent anodal and sham direct current stimulation for 5 consecutive days. Clinical assessment over a 1-month period was performed. RESULTS: A significant improvement of gait, as assessed by the Stand Walk Sit test, with reduction in number and duration of FOG episodes, along with a significant reduction in the Unified Parkinson's Disease Rating Scale score, were observed after anodal stimulation. Beneficial effects were more evident after the entire 5-day stimulation session, and persisted until the end of the observation period. CONCLUSIONS: Anodal transcranial direct current stimulation of the motor cortex is safe and has therapeutic potential in PD patients with FOG.