The unchanging face of Lennox-Gastaut syndrome in adulthood

Abstract Purpose Lennox-Gastaut syndrome (LGS) is a severe childhood-onset epileptic encephalopathy characterized by the presence of multiple types of intractable seizures, cognitive impairment, and specific electroencephalogram (EEG) patterns. The aim of this study was to investigate the electroclinical features of patients with LGS during adulthood. Methods We retrospectively identified the medical records of 20 patients aged over 18 years with a diagnosis of LGS from 3896 patients with epilepsy. Results Thirteen (65%) patients were male. The mean age of the patients was 23.4 ± 7.1 (min-max; 18-43) years, and the mean follow-up period was 5.6 ± 4.5 (min-max; 1-14) years. The etiology was identified in 11 (55%) patients. None of the patients achieved seizure freedom. The most prevalent seizure types were atypical absences in 14 (70%) patients, tonic seizures in 13 (65%) patients, and atonic seizures in 11 (55%) patients. One (5%) patient was diagnosed as having psychogenic non-epileptic seizures. Mental retardation was reported in all patients and only half of them could walk independently. All patients had drug-resistant seizures and 16 (80%) patients were on polytherapy. A vagus nerve stimulator was implanted into ten (50%) patients and five reported 50-80% seizure reduction. Ketogenic diet was administered to two (10%) patients and epilepsy surgery was performed in two (10%) patients with no significant benefit. Conclusions Paying attention to all factors of seizure outcomes, cognitive impairment, and ambulatory status, all patients were dependent on caregivers for daily living abilities. LGS has life-long persistence with poor outcomes, even during adulthood.