Background: Transcranial magnetic stimulation (TMS) is a non-invasive neuromodulation technique that has been closely examined as a possible treatment for Parkinson's disease (PD). Owing to various rTMS protocols and results, the optimal mode and suitable PD symptoms have yet to be established.
Objectives: This study intends to systematically evaluate the efficacy of rTMS intervention and identify optimal stimulation protocol of rTMS for specific motor symptoms.
Methods: PubMed and web of Science databases were searched before January 2022. Eligible studies included sham-controlled and randomized clinical trials of rTMS intervention for motor dysfunction in patients with PD. Standard mean difference (SMD) was calculated with random-effects models. The effects of rTMS on motor symptoms were mainly estimated by the UPDRS-III.
Results: A total of 1172 articles were identified, of which 32 articles met the inclusion criteria for meta-analysis. The pooled evidence suggested that rTMS relieves motor symptoms of patients with PD (SMD 0.64, 95%CI [0.47, 0.80]). High frequency stimulation on M1 is the most effective mode of intervention (SMD 0.79, 95%CI [0.52, 1.07]). HF rTMS has significant therapeutic effects on limbs motor function (SMD 1.93, 95%CI [0.73, 3.12] for upper limb function and SMD 0.88, 95%CI [0.43, 1.33] for lower limb function), akinesia (SMD 1.17, 95%CI [0.43, 1.92), rigidity (SMD 1.02, 95%CI [0.12, 1.92]) and tremor(SMD 0.91, 95%CI [0.15, 1.67]).
Conclusion: rTMS therapy is an effective treatment for motor symptoms of PD and the individualized stimulation protocols for different symptoms would further improve its clinical efficacy.
Keywords: Parkinson’s disease; meta-analysis; motor symptoms; transcranial magnetic stimulation.