Risk factors for status epilepticus after brain disorders in adults: A multi-cohort national register study

We aimed to describe risks of status epilepticus (SE) after different brain disorders in adults using population-wide register data. Our hypothesis was that SE would be more common in disorders with widespread pathology and that the risk would increase with disorder severity.

We analyzed five large datasets created from the Swedish National Patient Register, the Cause of Death Register, and national quality registers with adults in Sweden with brain infections, dementia, multiple sclerosis (MS), stroke, and traumatic brain injury (TBI). Risk factors were assessed using Cox regression.

In adults with TBI, stroke, dementia, MS, or brain infections, the incidence rate of SE was highest in survivors of brain infections (64/100,000 person years) and stroke (64/100,000), followed by TBI (37/100,000), dementia (36/100,000), and MS (26/100,000). SE was considerably more common in patients with epilepsy after their brain disorder. Across all datasets severe disorder increased SE-risk. Herpes simplex encephalitis (HR 5.5 95 % CI: 2.6-12), progressive MS (HR 2.3, 95 % CI: 1.1-4.7), structural TBI (2.0, 95 % CI: 1.6-2.6), and intracerebral hemorrhage (HR 1.5, 95 % CI: 1.2-2.0) were the subtypes of brain disorders with the highest relative risk of SE. Having another CNS disorder increased SE-risk in TBI (HR 2.9, 95 % CI: 2.3-3.7), brain infections (HR 2.8, 95 % CI: 1.7-4.5), and dementia (HR 2.5, 95 % CI: 1.5-4.2).

SE-risk increases with disorder severity and number of CNS comorbidities. These findings can guide treatment strategy by allowing identification of high-risk patients. Pathophysiological studies are needed to better understand remote symptomatic SE.