Influence of extent and age at corpus callosotomy on seizure outcomes. A single center experience.

Corpus callosotomy (CC) is a palliative treatment for drop seizures in patients with drug-resistant nonlocalizable epilepsy. We compared drop seizure outcomes between patients undergoing anterior CC versus complete CC and examined factors impacting outcomes for drop seizures including age at CC and duration of epilepsy. A retrospective review of patients who underwent CC between 2003-2022 with a minimum of 6 months post-surgical follow-up were included. Outcome measure for drop seizures included seizure reduction ≥50% from baseline as well as elimination of drop seizures. Thirty-eight patients were included. Overall, ≥50% reduction in drop seizures occurred in nearly 70% (23 out of 33) patients with complete elimination in 58% (19 out of 33). Compared with anterior CC (n=13), patients undergoing complete CC (n=25) had increased likelihood of ≥50% reduction (p=0.006) or elimination (p=0.024) of drop seizures. Regression analysis showed that complete CC was the primary predictor for improved drop seizure outcomes (elimination, p=0.014 or ≥50% reduction, p=0.006), while age at CC and duration of epilepsy did not impact the outcomes. Compared to anterior CC, Complete CC was significantly more likely to lead to improvement/freedom from drop seizures. Age at CC or duration of epilepsy did not influence drop seizure outcomes.