Extreme late onset of genetic generalized epilepsy in older adults and the elderly: A cohort study and literature review.

Rare case reports describe genetic generalized epilepsy (GGE) starting de novo in people ≥50 years of age (older adults and the elderly). We aimed to provide comprehensive detail of electro-clinical findings of this extremely late-onset GGE using a retrospective, single-center cohort design and a systematic review of the literature. People with de novo seizure onset ≥50 years of age with EEG and clinical history consistent with GGE were included. These 12 individuals (9; 75% females) with a median age of 56 years at seizure onset accounted for 7.9% of 152 older adults and the elderly with generalized epilepsy. Three patients only had absence seizures. A family history of epilepsy was present in 5 individuals. They had tried a median of 2 anti-seizure medications. More than 90% (11 of 12) were seizure-free for >1 year at the last follow-up, including four requiring monotherapy. Valproate was used in only two patients and levetiracetam in 75% of them. A systematic literature review revealed six papers with 10 extreme late-onset GGE cases. They similarly had good seizure outcomes but a majority were on valproate. Our study shows that rarely, late-onset epilepsy can be GGE, which mostly has a good prognosis.