Mild Traumatic Brain Injury as a Risk Factor for Parkinsonism, Tics, and Akathisia: A Systematic Review and Meta-Analysis.

This meta-analysis aimed to assess the association between mild traumatic brain injury (mTBI) and the risk of developing Parkinsonism. A systematic literature review was conducted using PubMed, Embase, and Cochrane Library databases. Studies were eligible if they reported on the association between MTBI and Parkinsonism. Pooled odds ratios (ORs) were calculated using a random-effects model. Publication bias was assessed using Egger's and Begg's tests. A total of 18 studies were included in this meta-analysis, with 1,484,752 participants. The overall OR for Parkinsonism in individuals with a history of mTBI was 1.637 (95% CI, 1.203-2.230; = 0.01), indicating a significant association. The OR for Parkinson's disease (PD) specifically was 1.717 (95% CI, 1.206-2.447; = 0.01). However, insufficient data on tics and akathisia limited a meta-analysis. There was no evidence of publication bias according to Egger's ( = 0.8107) and Begg's ( = 0.4717) tests. This meta-analysis provides evidence that mTBI is a significant risk factor for Parkinsonism, particularly PD. However, the findings should be interpreted with caution due to the heterogeneity among the studies included and the study's limitations. Further research is needed to confirm these findings and to investigate the underlying mechanisms of the mTBI-Parkinsonism association.