Related Experiment Video
Updated: Oct 24, 2026
Measuring and Manipulating Functionally Specific Neural Pathways in the Human Motor System with Transcranial Magnetic Stimulation
Published on: February 23, 2020
Effect of transcranial magnetic stimulation on focal hand dystonia: a systematic review and meta-analysis
Zeynep B Simsek1, Patrick J Mulcahey2, Michael W Lutz1
1Department of Neurology, Duke University School of Medicine, Durham, NC, United States.
Background:
Focal hand dystonia (FHD) is a rare and disabling movement disorder with limited treatment options. Transcranial magnetic stimulation (TMS) has shown promise as a non-invasive neuromodulation therapy for dystonia, but its efficacy in FHD remains unclear due to heterogeneity across prior studies and mixed results from broader noninvasive brain stimulation meta-analyses.
Objective:
To systematically review and synthesize the effects of TMS on behavioral symptoms in individuals with FHD.
Methods:
A systematic review and meta-analysis was conducted in accordance with PRISMA guidelines. PubMed, Embase, and Web of Science were searched through January 2026 for studies applying TMS in individuals with FHD. Studies reporting behavioral outcome measures of dystonia severity were included. Random-effects meta-analyses were performed to estimate pooled effect sizes using Hedges' g for (1) pre-versus post-TMS comparisons and (2) active-TMS versus sham-TMS comparisons. Study quality and risk of bias were assessed using Cochrane Risk of Bias and PEDro scales. Publication bias was assessed using funnel plot and Egger's test.
Results:
Nine studies met inclusion criteria, comprising a total of 111 individuals with FHD. Meta-analysis demonstrated a moderate and statistically significant improvement in dystonia symptoms following TMS compared with pre-TMS (Hedges' g = 0.36, 95% CI [0.17, 0.56], p < 0.001). In studies including sham controls (n = 8; 102 participants), active-TMS was associated with significantly greater symptom improvement compared with sham stimulation (Hedges' g = 0.35, 95% CI [0.12, 0.57], p = 0.002). Between study heterogeneity was low for both analyses, and no evidence of significant publication bias was detected.
Conclusion:
TMS is associated with a mild to moderate improvement in behavioral symptoms of FHD. These findings support further investigation of TMS as a non-invasive therapeutic option for FHD and highlight the need for larger, well-designed clinical trials to optimize stimulation parameters and assess durability of treatment effects.
