Long‐term outcomes and adaptive behavior in adult patients with Lennox–Gastaut syndrome

Abstract Objective Lennox–Gastaut syndrome (LGS) is a severe form of epilepsy characterized by difficult‐to‐control seizures and cognitive dysfunction. Previous studies mainly focused on pediatric populations, and little is known about the long‐term cognitive outcome in adult patients with LGS. The objective of this study was to investigate the long‐term functional and adaptive behavior in adult patients with LGS. Methods This cross‐sectional study enrolled adult patients diagnosed with LGS according to the recently published International League Against Epilepsy (ILAE) diagnostic criteria. The adaptive behavior of participants was assessed using the Vineland Adaptive Behavior Scales, Survey Interview, Second Edition (VABS‐II). Demographic, clinical, electroencephalography (EEG), and antiseizure medication (ASM) data were also collected at different timepoints, to investigate their association with VABS‐II scores. Results The study included 38 adult patients with LGS. A low score on the Adaptive Behavior Composite Scale was found in all patients. When considering single VABS‐II domains, particularly low scores were found in daily living skills and socialization, whereas slightly higher performances were observed in communication. An earlier age at LGS diagnosis was identified as the most significant predictor of worse adaptive outcomes in adult life. At the time of study evaluation, high seizure frequency, higher EEG background slowing, and multifocal EEG epileptiform abnormalities were significantly associated with lower VABS‐II raw scores. Furthermore, in an exploratory correlation analysis with ASM regimen at the study visit, treatment with cannabidiol was associated with higher adaptive behavior scores, whereas benzodiazepine intake correlated with lower scores. Significance This study provides relevant insights into the long‐term challenges faced by adults with Lennox–Gastaut syndrome (LGS), highlighting significant impairments in adaptive behavior as well as the associated clinical and electroencephalography features. Additionally, this study provides a more specific neuropsychological profile in adults with LGS and underscores the importance of comprehensive care approaches that go beyond seizure control in this population. Plain Language Summary This study examined adults with Lennox–Gastaut syndrome (LGS), a severe type of epilepsy, to understand their long‐term abilities to perform daily tasks and adapt socially. We found that these adults have significant difficulties with daily living and social skills, although not all areas were equally affected. They performed somewhat better in communication, particularly in understanding others (receptive communication). Importantly, the younger the age at which LGS was diagnosed, the worse their outcomes were as adults. This study highlights the need for research and treatment approaches that focus not only on controlling seizures but also on improving daily life skills.