Incidence and independently associated variables of acute postoperative seizures after epilepsy surgery

This study aimed to investigate the incidence and independently associated variables of acute postoperative seizures (APOS) occurring in the first postoperative week after resective epilepsy surgery.

We retrospectively analyzed clinical data from consecutive patients who underwent resective epilepsy surgery in a tertiary hospital. The clinical characteristics of patients with and without APOS were compared, and binary logistic regression was used to identify the independently associated variables of APOS.

Of the 1269 epilepsy surgeries (1261 patients) included in this analysis, 10.6 % (134/1269) resulted in APOS. Univariate analysis showed that sex, age at surgery, epilepsy duration, seizure frequency, number of anti-seizure medications (ASMs) at the time of surgery, drug resistant epilepsy (DRE); previous surgery, interictal EEG, intracranial monitoring, surgical extent, and complications were associated with APOS. When surgery was limited to a single brain lobe, frontal and parietal lobe surgery were more likely to result in APOS than temporal lobe surgery (11.7 %, 17.2 % vs. 7.5 %, p = 0.033, 0.008, respectively). Multivariate analysis demonstrated that an epilepsy duration of ≥3.75 years (OR 1.789 95 % CI 1.128-2.837 p = 0.013), using ≥3 types of ASMs at the time of surgery (OR 1.649 95 % CI 1.025-2.652 p = 0.039), and complications (OR 1.761 95 % CI 1.179-2.628 p = 0.006) were the independently associated variables of APOS. Postoperative seizure outcome at last follow-up was significantly worse in patients with APOS than in those without (Engel class Ⅰ: 41.1 % vs. 70.4 % p < 0.001).

The overall incidence of APOS in our cohort was moderate. Surgery for temporal lobe epilepsy was less likely to result in APOS. Early surgery, use of fewer ASMs, and control of complications were independently associated with a lower incidence of APOS.