Unilateral repetitive transcranial magnetic stimulation of the dorsolateral prefrontal cortex in Parkinson's Disease: a systematic review and meta-analysis

Abstract

Introduction: Repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex (DLPFC) may improve motor and non-motor symptoms in Parkinson's disease (PD). This meta-analysis assessed the efficacy of 10 unilateral rTMS sessions in PD.

Evidence acquisition: Randomized controlled trials comparing this protocol to sham stimulation in PD were systematically searched in PubMed, EMBASE, and the Cochrane Library through January 2025. Short-term outcomes were assessed immediately after treatment; long-term outcomes were measured 1-6 months later. Mean differences (MDs) with 95% confidence intervals (CIs) were calculated using random-effects models.

Evidence synthesis: Seven trials were included (mean follow-up: 8.7 weeks). Long-term motor function improved significantly (UPDRS part III: MD=-4.97; 95% CI: -6.53 to -3.40; P<0.001), whereas short-term changes were non-significant. Long-term reductions in depressive symptoms were observed on the Hamilton Depression Rating Scale (MD=-2.77; 95% CI: -4.75 to -0.79; P=0.006), the Montgomery-Åsberg Depression Rating Scale (MD=-6.23; 95% CI: -9.78 to -2.68; P<0.001), and the Beck's Depression Inventory (MD=-4.41; 95% CI: -8.34 to -0.48; P=0.028). Sleep quality improved at long-term follow-up (Pittsburgh Sleep Quality Index: MD=-2.51; 95% CI: -5.33 to -0.31; P=0.081). Short-term cognitive gains were observed on the Montreal Cognitive Assessment (MD=1.70; 95% CI: 0.01 to 3.40; P=0.049).

Conclusions: Ten sessions of unilateral rTMS over the DLPFC improved motor and non-motor symptoms.