Awake craniotomies for epileptic gliomas: intraoperative and postoperative seizure control and prognostic factors.

PURPOSE: Awake craniotomy is well-established for tumors resected in eloquent brain areas. Whether awake craniotomy provides improved seizure control in patients with epileptic gliomas has not been well evaluated. This study analyzed the incidence, risk factors and outcome of seizures during and following awake craniotomies for patients presenting with epilepsy and glioma.

METHODS: Forty-one patients undergoing awake craniotomies for epileptic gliomas were retrospectively analyzed. Postoperative seizure was defined as either early (postoperative day 7 + before) or late onset (after postoperative day 7). Neurologic function was assessed with modified Rankin Scales (mRS) and seizure outcome was assessed using International League Against Epilepsy (ILAE) classification. Multivariable logistic regression was used for clinical variables associated with postoperative seizures.

RESULTS: Three patients (7.3%) had intraoperative seizures however did not fail the awake craniotomies. Mean mRS before and after the awake craniotomies were 2.4 and 2.1, respectively (P = 0.032). Fourteen (34.1%) patients had early seizures, which caused longer hospitalization than those without early seizures (P = 0.03). Surgical resection to isocitrate dehydrogenase 1 (IDH1) mutation tumors, comparing to IDH1 wild type tumors, caused better postoperative seizure control. 6-month late seizure freedom was achieved in 33 patients (80.5%). Early seizure recurrence (odds ratio = 30.75; P = 0.039) and postoperative mRS ≥ 3 (odds ratio = 7.00; P = 0.047) were independent risk factors for late seizures.

CONCLUSIONS: Intraoperative seizures could be well-controlled during awake craniotomies. Early postoperative seizures extended hospitalization and strongly predicted late seizure recurrence. Awake craniotomies benefited long-term seizure control in patients with epileptic gliomas.