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

Objective: The 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 Methods: From 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.

Results: Before 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).

Conclusion: The focal BS was observed during temporal lobectomy and this unusual pattern does not affect the surgical outcome in patients with TLE.