Incidence and outcomes of head injuries in people with and without Parkinson disease

Abstract

Background and purpose: Fall-related injuries are a major health concern among people with Parkinson disease (PD). We compared the incidence and postinjury mortality of head injuries and traumatic brain injury (TBI) among persons with and without PD. Methods: This register-based study was conducted on the FINPARK cohort, which includes 22,189 persons who were diagnosed with PD in Finland during 1996–2015. We excluded persons with a previous head injury, leaving 20,514 persons with PD. For each person with PD, 1–7 matching persons without PD and previous head injury were identified with respect to age, sex, and residence. The Cox proportional hazard model was used to estimate hazard ratios for head injury. A logistic regression model was used to compare mortality. Results: Persons with PD had 2.16-fold (95% confidence interval [CI] = 2.06–2.26) risk of all head injuries and 1.97-fold (95% CI = 1.84–2.10) risk of TBI after adjustment for age, sex, and comorbidities. Persons with PD had higher 1-year mortality after any type of head injury (adjusted odds ratio [aOR] = 1.44, 95% CI = 1.28–1.62), TBI (aOR = 1.33, 95% CI = 1.14–1.57), or non-TBI head injury (aOR = 1.72, 95% CI = 1.42–2.07) than persons without PD. The higher risk of mortality was observed 6 months after TBI and 1 month after non-TBI injury in persons with PD. Persons with PD and head injury also had higher 1-year mortality than persons with PD and without head injury. Conclusions: Persons with PD have a higher risk of head injury and higher postinjury mortality than persons without PD.