@article{ref1,
title="Repeated traumatic brain injury and risk of epilepsy: a Danish nationwide cohort study",
journal="Brain: a journal of neurology",
year="2021",
author="Christensen, Jakob and Dreier, Julie W. and Lolk, Kasper",
volume="ePub",
number="ePub",
pages="ePub-ePub",
abstract="Traumatic brain injury is associated with increased risk of epilepsy, but the importance of repeated traumatic brain injuries has not yet been established. We  performed a nationwide population-based cohort study of 2 476 905 individuals born  in Denmark between 1977 and 2016. We estimated hazard ratios (HRs) and the  cumulative incidence of epilepsy following traumatic brain injury using Cox and  competing risk regression, respectively. To estimate the cumulative incidence of  epilepsy in the population without traumatic brain injury, we matched 10 controls  for each subject with traumatic brain injury on year of birth, sex, and date of  brain insult in the index person. In the cohort, traumatic brain injury was  sustained by 167 051 subjects (71 162 females and 95 889 males), and 37 200  individuals developed epilepsy (17 905 females and 19 295 males). Compared with  subjects without traumatic brain injury, the relative risk of epilepsy increased  after a first traumatic brain injury [HR 2.04, 95% confidence interval (CI)  1.96-2.13] and even more after a second traumatic brain injury (HR 4.45, 95% CI  4.09-4.84). The risk increased with the severity of the first and the second  traumatic brain injury, most notably after severe traumatic brain injuries. Females  were more likely than males to develop epilepsy after mild traumatic brain injury  (HR 2.13, 95% CI 2.00-2.28 versus HR 1.77, 95% CI 1.66-1.88; P < 0.0001); in  contrast, males were more likely than females to develop epilepsy after severe  traumatic brain injury (HR 5.00, 95% CI 4.31-5.80 versus 3.21, 95% CI 2.56-4.03;  P = 0.0012). The risk remained increased for decades after the traumatic brain  injury. This knowledge may inform efforts to prevent the development of  post-traumatic epilepsy.<p /> <p>Language: en</p>",
language="en",
issn="0006-8950",
doi="10.1093/brain/awaa448",
url="http://dx.doi.org/10.1093/brain/awaa448"
}