To describe the clinical course of Lennox Gastaut Syndrome (LGS) in adults and its association with clinical outcomes.

LGS is a childhood-onset electroclinical epilepsy syndrome classified as an epileptic encephalopathy with known behavioral symptoms. Although well-defined in children, the clinical course and management of LGS in adult patients remain less clearly delineated.

Patients in the Adult Comprehensive Epilepsy Clinic at a tertiary center were retrospectively reviewed for the diagnosis of LGS. Data parameters, including demographics, seizure frequency, psychiatric comorbidities, diagnostics, and treatment, were collected. Refractory Epilepsy Screening Tool for Lennox–Gastaut Syndrome (REST-LGS) scores were calculated. Parametric statistics were applied to evaluate clinical associations.

Twenty-seven adult LGS patients (17 male, 63.0%) were identified and verified by REST-LGS as likely (n=25) or possible (n=2). Patients were predominantly Black(75.0%), with a mean age of 36 years (range: 25-55). Average seizure frequency was 15/month (range: 2-80/month); bilateral tonic clonic seizures (88.8%) and drop attacks (66.6%). Neuroimaging revealed mostly malformation of cortical development(33.3%) and anoxic brain insult (22.2%). All patients require polytherapy antiseizure medications(ASM) (mean=4.0; range 3-5). The most commonly used ASM were Levetiracetam(55.5%), Cannabidiol (40.7%), Lacosamide (33.3%), Lamotrigine (29.6%), and Brivaracetam (29.6%). Patients had a history of VNS implantation(59.2%) or another type of epilepsy surgery (22.2%). Patients with agitation(33%) had a lower mean seizure frequency of 9.1 vs. 19.8 seizures/month using a confirmatory negative binomial regression model(IRR = 1.97, 95% CI 0.85–4.54, p=0.24).

Adult LGS can remain in refractory despite medical and surgical intervention. Medications used in our cohort differed from Tier 1 pediatric agents. In addition, findings suggest a possible trend in which patients with lower seizure frequency were more likely to exhibit agitation, without reaching statistical significance. Our results emphasize the ongoing evolution of clinical features and management strategies in the adult LGS population and highlight the need for more long-term data.