To investigate how seizure symptoms and severity change as adults age and identify factors associated with this evolution.

Epilepsy is a dynamic condition, and seizure characteristics may evolve with age due to neurobiological aging processes and emerging comorbidities.

The Liverpool Seizure Severity Scale (LSSS), a patient reported tool that assesses seizure symptoms in 12 dimensions, was used to measure seizure-related features longitudinally. Analysis included adults with ≥3 LSSS scores collected over ≥5 years between 08/2007 and 03/2025 at our epilepsy center. Independent variables were age and Charlson Comorbidity Index (CCI). Epilepsy types were categorized as focal, generalized or unknown. Mixed effects linear regression and proportional odds logistic regression were used to model LSSS total and item scores, respectively.

A total of 1,486 patients met the inclusion criteria. At baseline, median age was 36 (IQR: 26–48), 57.8% were female, and 81.2% Caucasian. Average baseline LSSS total score was 50.3± 21.7, and median CCI was 2 (IQR: 2–3). Median self-reported seizure frequency over the prior four weeks was 3 (IQR: 1–8). Epilepsy type was focal in 58.7%, generalized in 9.8%, and unknown in the rest. Median number of visits with available LSSS data was 8 (IQR = 5–12), and median follow-up was 9 years (IQR = 6.4–11.0). Older age was associated with faster improvement in LSSS total and all item scores (all p-values <0.05). Higher comorbidity burden was associated with faster improvement in LSSS total score, post ictal confusion level, fall frequency, and post ictal return to baseline (all p-values <0.05).

Aging was associated with reduction in seizure severity and a faster improvement in all seizure-related features. Higher comorbidity burden was independently associated with faster improvement in post ictal confusion level, fall frequency, and post ictal return to baseline. These findings highlight how aging and comorbidities affect seizure characteristics in adults.