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

PURPOSE: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Second antiseizure medication monotherapy in patients with adult-onset epilepsy: A register-based analysis.

OBJECTIVE: Revision of therapy is fundamental in epilepsy care, since only half of patients achieve seizure freedom and tolerate the first antiseizure medication (ASM). We studied the selection and retention of second antiseizure medication monotherapy in adults who discontinued treatment with one of the three most frequently prescribed first ASMs, and the impact of age or brain comorbidities. METHODS: Using Swedish national registers, we conducted a population-based, retrospective cohort study from 2007 to 2019 on patients age ≥ 30 at the epilepsy diagnosis that had switched to a second monotherapy after the three most common initial monotherapies (n = 7369). Retention rates (RR) were estimated via Kaplan-Meier. Discontinuation of the second monotherapy was defined as 12-month prescription gap or initiation of a third ASM. Analyses were stratified by sex, age, and presence of stroke or dementia. RESULTS: The three most commonly prescribed second ASMs were carbamazepine, levetiracetam, and lamotrigine. The 1-year retention rate was 63-76% in all patients. For groups with stroke or dementia, the maximal 1-year RRs were 77% and 87%, respectively. After five years, retention rates ranged from 12% to 39%. There were no major differences between ASMs, apart from in patients discontinuing carbamazepine, where lamotrigine had a superior retention compared to levetiracetam as second monotherapy. SIGNIFICANCE: The three most often prescribed second ASMs seem to be suitable treatment options according to present guidelines. The second ASMs' retention rates were initially high in all studied patient groups but dropped to approximately the expected proportion of second monotherapy responders over the next five years. This suggests that therapy revision could be expedited.