Head Injury and Parkinson Disease: Updated Evidence from Meta-Analysis Studies

Abstract Background Published studies on head injury and Parkinson's risk(PD) were inconsistent. We performed a meta-analysis study to explore the association.Methods We retrieved articles published in English from PubMed, Web of Science, Scopus and ScienceDirect between January 1, 1990 and December 31, 2019. The pooled effect of head injury and PD risk was calculated by a random effect model.Results In the meta-analysis, there were 21 studies, including 214763 individuals and 39209 PD patients. The pooled OR estimates(ORs) showed an increased risk of PD was correlated with head injury(OR = 1.46, 95% CI 1.29–1.66). Considering the unconscious state, head injury with LOC showed significant association with PD(OR = 1.49, 95%CI 1.28–1.74). However, head injury without LOC had no significant association with PD (OR = 0.57, 95% CI 0.29–1.12). Sensitivity analysis showed that, when any one study was excluded, the results did not change significantly.Conclusions Our research shows that head injury was associated with PD risk.This study provides a basis and reference for further study on head injury and PD.