Patients who suffer a traumatic brain injury (TBI), such as a fall, car accident, or sports-related injury, are at an increased risk for experiencing a seizure. The most common types of seizures caused by a TBI are partial (or focal) seizures and tonic-clonic seizures.

Patients who suffer more severe injuries, such as penetrating head injuries, skull fractures, or injuries that result in a coma that lasts more than 24 hours, are more likely to develop post-traumatic epilepsy. If a patient experiences seizures early (within two weeks) following a TBI, he or she is more likely to develop post-traumatic epilepsy.

Most patients with post-traumatic epilepsy (approximately 80 percent), start having seizures within two years. Approximately one-half of patients who develop post-traumatic epilepsy have periods of time when they do not experience seizures.

Anti-seizure medications used after a TBI may decrease the risk of early post-traumatic seizures but may not lower the risk of seizures later following a TBI.