This retrospective study examined a diverse population of patients on a wide range of ASDs and allowed for patient outcomes on different medication regimens to be evaluated over an extensive period of time, presenting a unique opportunity to evaluate the incidence of seizure aggravation.

Despite the availability of >25 ASDs, long term rates of remission, efficacy and tolerability have not significantly improved. There are numerous reports of seizure aggravation related to specific ASDs; however, a quantitative analysis with clearly defined parameters for seizure exacerbation is lacking.

In this retrospective study, we reviewed all patients who visited four epileptologists as an outpatient in the Baylor College of Medicine Comprehensive Epilepsy Center between August 2018 and May 2019. Seizure exacerbation was defined as a >200% increase in seizures after initiation of an ASD, with return to baseline after ASD discontinuation. Patients were then stratified into two categories: (1) patients who did not report seizure aggravation and (2) patients who reported seizure aggravation with clear documentation of an increasing number of seizures after AED initiation. Patients with seizure aggravation were then further evaluated to ensure there was a clear quantification of seizure frequency, no suspected trigger such as infection or stress, and documentation of compliance.

Out of a total of 190 encounters where an ASD was initiated, we found that 10.97% of our patient population described experiencing seizure aggravation, although this dropped to 4.21% when adjusting for patients who may have had alternate etiologies for their seizure aggravation.

We conclude that aggravation of seizures with initiation of an ASD may occur in the outpatient setting, but the attribution of exacerbation to the initiation of an ASD is rare. Further study is required to identify the specific factors that may be associated with ASD-induced seizure exacerbation.