Efficacy of Repetitive Transcranial Magnetic Stimulation Over the Supplementary Motor Area on Motor Function in Parkinson's Disease: A Meta-analysis.
Qi-Qi Lu, Ping-An Zhu, Zhi-Liang Li and 5 others
PMID 38935062WHAT IT FOUND
Across seven trials of 374 people with Parkinson's disease, rTMS aimed at the supplementary motor area improved UPDRS-III motor scores more than sham.
The trials disagreed widely, so how big that benefit is remains uncertain.
Key findings
01In seven trials of 374 people with Parkinson's disease, rTMS aimed at the supplementary motor area improved UPDRS-III motor scores compared with sham, with a pooled effect of −1.24 (95% CI, −2.24 to −0.24; P = 0.02). A negative value here means better motor scores, because lower UPDRS-III scores are better.
02The seven trials disagreed far more than chance would explain (I² = 93%), and dropping studies one at a time did not reduce that disagreement, so the pooled figure is an average across trials that were not measuring the same thing.
03In a subgroup comparison, high-frequency stimulation (5 Hz or more) improved UPDRS-III scores more than low-frequency stimulation (1 Hz): pooled effect −1.39 (95% CI, −2.21 to −0.57; P = 0.04). This rests on only two low-frequency trials covering 92 patients, which the authors themselves describe as not producing firm or robust results.
STILL TO COME
How it was doneWhat they foundWhat it means for PTs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
Only seven trials and 374 patients in total, and they disagreed enormously (I² = 93%). The authors tried removing studies one at a time and still could not find what caused the disagreement, which means the pooled number is an average of studies that were not measuring the same thing. The comparison between high-frequency and low-frequency stimulation rests on two small low-frequency trials covering 92 patients. The authors say this does not produce firm or robust results and call for a larger sample. The range of possible benefit is wide: the data are compatible with anything from a very large effect to almost none, since the confidence interval upper bound sits close to no difference at all. Treatment length varied from 3 days to 20 weeks across the trials, but the pooled analysis used scores at 4 weeks. Nothing in the paper says whether any benefit lasts beyond the treatment period. Several of the included trials focused on patients with freezing of gait, which the authors say could introduce bias, and they note that uncontrolled differences between patients and disease-related factors could have influenced the results.
Declared interests
The authors state that financial disclosure statements were obtained and that no conflicts of interest were reported by them or by anyone in control of the article's content. Funding is listed as not applicable, so there was no commercial sponsor.
The easy way to misread this
Do not read this as an established treatment with a large and reliable effect. The seven trials disagreed far more than chance alone would explain, the authors could not find the reason for that disagreement despite checking it several ways, and the range of possible benefit runs from a large effect to almost none. The comparison favouring high-frequency over low-frequency stimulation rests on just two small low-frequency trials, and the authors themselves say the evidence is early and needs larger, more rigorous trials.
Summarised by AI from the full paper, without a clinician reviewing it. Check it against the source before it changes what you do. Read it on PubMed →