This retrospective, single-center study investigated the differences in clinical presentation, seizure characteristics, and workup between late-onset-epilepsy(LOE) and early-onset-epilepsy(EOE) to improve prognostication and develop targeted interventions.

LOE is an entity distinct from EOE. It poses unique diagnostic and therapeutic challenges.  Despite this, LOE remains understudied. Further research can elaborate on how it differs to optimize management strategies.

All patients who presented to our hospital with clinically-diagnosed epilepsy from 8/2024-9/2024 were included. Patients were categorized into EOE vs LOE based on an age-at-onset-cutoff of 65 years. Data on baseline demographics, seizure characteristics, comorbidities, and workup were obtained from EMR. Data were analyzed using Pearson’s Chi-squared test, Fisher's exact test, or t-tests.

Of the 74 patients meeting the inclusion criteria, 37(50%) were LOE. The mean age at epilepsy onset was 57.7±8.2 years for EOE and 72.8±6.3 years for LOE(p<0.001). Women were more likely to have LOE than EOE(LOE=62.2% vs EOE=37.8%,p=0.0377).  LOE were more likely to be white than non-white(89.2% vs 70.3%,p=0.0496). EOE were more likely to be disabled than LOE(16.2% vs 0%,p=0.010). The burden of comorbidity was significantly greater in LOE(mean Charlson-Comorbidity-Index:5.11±2.07 vs.3.84±1.95,p=0.0082). Both groups had similar proportions of focal and generalized seizures. Drug-resistant-epilepsy(DRE) was observed in 4(10.8%)EOE, against none in LOE. Routine EEG was performed in 25(67.6%)EOE and 27(73.0%)LOE; seizures were recorded in one patient from each group. Epileptiform discharges or seizures were comparable in EOE and LOE(28.0% vs 25.9%). Overall, 92.5% of patients had MRI abnormalities.

LOE and EOE patients exhibit distinct clinical profiles, with LOE patients more frequently female and white, and demonstrating greater comorbidity and lower levels of disability. DRE was observed only in EOE. EEG findings revealed epileptiform abnormalities in >25% of the overall cohort. These differences underscore the need to investigate LOE as a distinct epilepsy type to develop individualized management strategies based on age of onset.