Cerebellar transcranial magnetic stimulation improves motor function in Parkinson's disease

Abstract

Objective: To determine whether an accelerated protocol of 48 Hz cerebellar repetitive transcranial magnetic stimulation results in improved motor function in individuals with Parkinson's disease.

Methods: In this double-blind randomized sham-controlled study, 35 individuals with Parkinson's disease and stable medical treatment were randomized to either sham or verum transcranial magnetic stimulation. The stimulation was applied bilaterally and medial over the cerebellum and comprised a novel accelerated protocol encompassing two sessions per day on 5 consecutive days. Patients were assessed at baseline, on day 5 after the last stimulation and 1 month post intervention. Measurements included dynamic posturography, UPDRS III, 8-Meter walk test, and Timed Up and Go test.

Results: The accelerated protocol was safe and feasible in an outpatient setting. Patients in the verum group showed significant improvement (p < 0.001) of motor symptoms as measured in the UPDRS III. Improvement was mainly carried by the domains rigor, bradykinesia, and gait and persisted after 1 month (p = 0.009), whereas tremor remained unchanged.

Interpretation: The effect of a high-dose transcranial magnetic stimulation in patients with Parkinson's disease is encouraging and comparable to other studies using much longer stimulation protocols. This short-term intervention of 5 days facilitates the future application in an outpatient setting. Reduction in hospitalization rates directly benefits patients with motor impairment.

Figure 1

Study protocol.

Figure 2

Boxplots of UPDRS scores for verum (A) and sham (B) group. Scores were obtained before rTMS stimulation (V0), after last therapy session (V1) and 1 month later (V2). The star symbols present the mean values of sham and verum visits, results of group comparisons are shown as ns (not significant), ** for p ≤ 0.01 and *** for p ≤ 0.001.