Is the Cerebellum a Potential Target for Stimulation in Parkinson's Disease? Results of 1-Hz rTMS on Upper Limb Motor Tasks

Abstract

The aim of this study was to find whether 1-Hz cerebellar repetitive transcranial magnetic stimulation (rTMS) could affect upper limb movement in early-stage Parkinson's disease (PD). Twenty patients with PD underwent one session with real and one with sham rTMS. rTMS (1Hz, 600 pulses) was targeted at the right lateral cerebellum. Before and after rTMS, patients performed two motor tests with their fingers and hands (ball test, nine-hole peg test). The duration of these tests was measured. There were statistically significant differences (p < 0.05) in the results of the tests after real stimulation and sham stimulation. We excluded the impact of learning. After real rTMS, we observed a significantly faster response in the ball test and a slower response in the nine-hole peg test, both on the right upper limb. This study indicates the influence of 1-Hz cerebellar rTMS in modifying the voluntary movements of the upper limb in PD. This influence is differentiated: the improvement of gross motor skills and the worsening of fine motor skills.