Epilepsy and disability in adults with tuberous sclerosis complex: a 16-year retrospective analysis.

To identify factors associated with persistent seizures and disability in adults with tuberous sclerosis complex (TSC)-related epilepsy. Retrospective single-center cohort study of adults with TSC followed in Paris (2005-2021). Patients without a seizure history were excluded. Clinical, neuroimaging, and genetic data were collected. Seizure freedom was defined as ≥ 12 months without seizures before last follow-up; disability as modified Rankin Scale (mRS) > 2. Univariable and multivariable logistic regression were used; outcomes were compared between TSC1 and TSC2. Adult-onset epilepsy and mosaic cases were described. Of 180 adults with TSC, 148 were included. At last follow-up, 41.2% were seizure-free and 34.5% had mRS > 2. Persistent seizures were associated in univariable analysis with childhood drug-resistant epilepsy (DRE) (OR 4.98; 95% CI 2.43-10.7), status epilepticus (OR 5.25; 95% CI 1.89-18.7), and severe intellectual disability; only childhood DRE remained significant after adjustment. Disability was associated in univariable analysis with onset before 1 year, spasms at onset, status epilepticus, and childhood DRE. In multivariable analysis, spasms at onset (OR 4.78; 95% CI 1.76-13.7) and childhood DRE (OR 4.65; 95% CI 1.66-13.7) remained significant. Adult-onset epilepsy was rare (5.4%) and generally mild. TSC2 mutations were associated with more severe cognitive and organ involvement but did not influence adult seizure persistence. Childhood drug-resistant epilepsy was the strongest predictor of persistent adult seizures and disability. TSC2 mutations were linked to a more severe phenotype but does not predict the course of epilepsy in adulthood. These results support early, optimized seizure management.