Post-traumatic epilepsy: Risk factors, Clinical insights, Socioecinomic aspects and prognosis

Abstract

Traumatic brain injury (TBI) is a common cause of acquired epilepsy, and the risk of post-traumatic epilepsy (PTE) increases with the severity of the TBI. The risk of PTE varies in the literature, and following a post-traumatic seizure (PTS), it is uncertain when an individual fulfills the diagnostic criteria for PTE, as the risk of seizure recurrence varies, and most studies are based on smaller cohorts. Additionally, drug resistant epilepsy, medical retirement and unemployment seem to be more common among war-veterans with PTE, compared to other types of epilepsy. In general, individuals with PTE do also have an increased risk of death compared to individuals with a TBI without subsequent epilepsy. However, it remains unclear if this is due to the epilepsy itself or related to other factors.

The results from this thesis, including nation-wide data, showed that individuals with a TBI in Sweden had a risk of 4.0% for epilepsy within ten years. The risk increased to 12.9% after the most severe TBI. Acute symptomatic seizures were a strong risk factor. The risk of seizure recurrence after a first post-traumatic seizure increased with the severity of the TBI and was additionally increased if the first seizure occurred <2 years after the TBI. However, the risk of seizure recurrence after milder TBI was comparable to that in individuals without prior TBI.

Individuals with PTE were more frequently unemployed than those with epilepsy of unknown etiology. They were also less likely to hold a university degree, but did not seem to have a more severe epilepsy. They also had an increased risk of death, with an unadjusted hazard ratio of 2.3, compared to individuals with a TBI without later epilepsy. Epilepsy was a contributing factor in 18.4% of deaths.

The thesis highlights a considerable risk of epilepsy among individuals following a more severe TBI, particularly when acute symptomatic seizures occur after the trauma. In most cases, PTE should be diagnosed after two unprovoked epileptic seizures, similar to epilepsy without a prior brain injury. The results also emphasize the need for proper epilepsy care and rehabilitation following the trauma.