Objective It has been stated that concussion is a risk factor for the development of post-traumatic epilepsy, but few data exist to support or refute this statement. We analysed the incidence and prevalence of epilepsy in a large cohort of post-concussion patients.

Design Retrospective cohort study.

Setting Academic tertiary care centre.

Participants 330 consecutive post-concussion patients followed by one concussion specialist (CHT). Exclusion criteria: abnormal brain CT/MRI, GCS ≤ 12 >1 hr post-injury, hospitalisation>48 hrs. Mean number of concussions/patient 3.3 (±2.5), mean age at first clinic visit 28 years (±14.7), mean follow-up after first concussion 7.6 years (±10.8).

Assessment of risk factor Independent variable, concussion.

Outcome measures Epilepsy incidence (dependent variable); prevalence.

Main results Eight patients had medical record documentation of seizures or convulsions or epilepsy. Upon detailed review by an epilepsy specialist (RW) none met criteria for a definite diagnosis of epilepsy: 4 had episodic symptoms incompatible with epileptic seizures (multifocal paraesthesiae, multimodality hallucinations, classic migraine) and normal EEG/MRI investigations; 4 had clear histories of syncopal (n=2) or concussive (n=2) convulsions. Compared to epilepsy prevalence (6.6/1000 individuals) and annual incidence (0.5/1000 individuals) in the general population, there was no difference in this post-concussion cohort (Chi-square=0.218, d.f.1, corr.cont., p=0.64).

Conclusions In this large cohort of post-concussion patients we found no evidence of an increased incidence of epilepsy, and the prevalence of epilepsy was lower than in the general population. Concussion is not a significant risk factor for the development of post-traumatic epilepsy, at least in the first decade post-injury.

Competing interests None.