Focal burst suppression on intra-operative electrocorticography does not affect the surgical outcome in patients with temporal lobe epilepsy

Abstract

ObjectiveThe aim of this study was to investigate the burst suppression (BS) pattern on intra-operative electrocorticography (ECoG) in patients with temporal lobe epilepsy (TLE) and the surgical outcome. Patients and methodsFrom January 2017 to June 2017, 45 patients with TLE underwent temporal lobe resection with intra-operative ECoG at the Beijing Institute of Functional Neurosurgery of Xuanwu Hospital of Capital Medical University, China. The scalp EEG, pre-operative and post-operative ECoG were analyzed. Surgical outcome was evaluated with Engel's classification every 3 months, 6 months and 1 year after surgery. ResultsBefore temporal lobe resection the ECoG showed a variable amount of interictal spiks in all patients. A different pattern of burst suppression (BS) was recorded in 33.3% (n = 15; male:7, female:8; mean age, 26.9 years; range 3–45 years) in a small zone of temporal cortex. The BS is characterized of a suppression pattern with bursts of high-amplitude spike rhythm or low amplitude fast activity. After the temporal lobe resection, BS was disappeared in 26.7% (4/15), 73.3% (n = 11) showed the focal BS pattern in a cortex adjacent to the margin of resection, 20% (n = 3) had no epileptiform abnormality, and 40% (n = 6) had minor spikes. The mean postoperative follow-up was 14 ± 2.1 months, 73.3% (n = 11) were class I and 26.7% (n = 4) were class Ⅱ (Engel's classification). ConclusionThe focal BS was observed during temporal lobectomy and this unusual pattern does not affect the surgical outcome in patients with TLE.