Head injury and risk of Parkinson disease: A systematic review and meta-analysis

Authors

  • Siavash Jafari MD, MHSc,

    1. School of Population and Public Health, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
    Search for more papers by this author
  • Mahyar Etminan PharmD,

    1. Therapeutic Evaluative Unit, Provincial Health Services Authority, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
    Search for more papers by this author
  • Farhad Aminzadeh BSc,

    1. St. George's University School of Medicine, Newcastle, United Kingdom
    Search for more papers by this author
  • Ali Samii MD

    Corresponding author
    1. Seattle Parkinson Disease Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, USA
    • Department of Neurology, University of Washington, Seattle, Washington, USA
    Search for more papers by this author

  • Relevant conflicts of interest/financial disclosures: Nothing to report.

  • Full financial disclosures and author roles may be found in the online version of this article.

Correspondence to: Dr. A. Samii, Professor of Neurology, University of Washington, Seattle Parkinson Disease Research Education and Clinical Center, Veterans Affairs Puget Health Care System, 1660 S. Columbian Way, Seattle, WA 98108; asamii@u.washington.edu

Abstract

Head trauma has been implicated in the etiopathogenesis of Parkinson's disease (PD). We performed a meta-analysis to investigate the association between head trauma and the risk of developing PD. We included observational studies if they (1) clearly defined PD, (2) defined head trauma leading to concussion, and (3) presented odds ratios (ORs) and 95% confidence intervals (CIs) or provided data to compute these statistics. Random effect model was used to estimate the pooled, adjusted OR. Heterogeneity between studies was evaluated with the Q test and the I2 statistic. We conducted a sensitivity analysis to assess the influence of each study and repeated the analysis by excluding the studies with the largest weights. We used funnel plot to assess the presence of publication bias. After reviewing more than 636 article titles, 34 articles were selected for full review. In total, 22 studies (19 case–control studies, 2 nested case–control studies, and 1 cohort study) were included in the meta-analysis. The pooled OR for the association of PD and head trauma was 1.57 (95% CI, 1.35–1.83). The results of our meta-analysis indicate that a history of head trauma that results in concussion is associated with a higher risk of developing PD. © 2013 Movement Disorder Society

Ancillary