Is Concussion a Risk Factor for Epilepsy?

Can J Neurol Sci. 2018 May;45(3):275-282. doi: 10.1017/cjn.2017.300. Epub 2018 Mar 20.


Background: Epidemiologic studies have suggested that concussion, or mild traumatic brain injury (mTBI), is associated with a twofold or greater increase in relative risk for the development of post-traumatic epilepsy. To assess the clinical validity of these findings, we analyzed the incidence of epilepsy in a large cohort of post-concussion patients in whom concussion was strictly defined according to international guidelines.

Methods: A retrospective cohort study of 330 consecutive post-concussion patients followed by a single concussion specialist. Exclusion criteria: abnormal brain CT/MRI, Glasgow Coma Scale48 hours. Independent variable: concussion. Outcome measure: epilepsy incidence (dependent variable).

Results: The mean number of concussions/patient was 3.3 (±2.5), mean age at first clinic visit 28 years (±14.7), and mean follow-up after first concussion 7.6 years (±10.8). Eight patients were identified whose medical records included mention of seizures or convulsions or epilepsy. Upon review by an epileptologist none met criteria for a definite diagnosis of epilepsy: four had episodic symptoms incompatible with epileptic seizures (e.g., multifocal paraesthesiae, multimodality hallucinations, classic migraine) and normal EEG/MRI investigations; four had syncopal (n=2) or concussive (n=2) convulsions. Compared with annual incidence (0.5/1000 individuals) in the general population, there was no difference in this post-concussion cohort (p=0.49).

Conclusion: In this large cohort of post-concussion patients we found no increased incidence of epilepsy. For at least the first 5-10 years post-injury, concussion/mTBI should not be considered a significant risk factor for epilepsy. In patients with epilepsy and a past history of concussion, the epilepsy should not be presumed to be post-traumatic.

Keywords: Convulsion; Incidence; Mild traumatic brain injury (mTBI); Prevalence; Seizure.

MeSH terms

  • Adolescent
  • Adult
  • Brain Concussion / complications*
  • Brain Concussion / diagnostic imaging
  • Brain Concussion / epidemiology*
  • Cohort Studies
  • Electroencephalography
  • Epilepsy / diagnostic imaging
  • Epilepsy / epidemiology*
  • Epilepsy / etiology*
  • Epilepsy / physiopathology
  • Female
  • Glasgow Coma Scale
  • Humans
  • Incidence
  • Magnetic Resonance Spectroscopy
  • Male
  • Risk Factors
  • Tomography Scanners, X-Ray Computed
  • Young Adult