Patients

We retrospectively reviewed the ECoG data of 16 consecutive patients with a brain tumor who underwent an awake craniotomy during intraoperative neuromonitoring–assisted surgical resection of their lesion between September 2016 and June 2017. All but 2 cases were performed by the senior surgeon (A.Q.-H.). Clinical data, including demographics, presence of preoperative seizures, tumor location, WHO tumor grade, and various genetic tumor markers such as 1p/19q codeletion, p53 overexpression, and IDH1 mutation status, were assessed.

Operative technique Patients had monitored anesthesia care technique used for sedation as described previously.17,18 Briefly, 2 cases were performed with general anesthesia and sleep-awake-sleep technique with remifentanil and propofol infusions as the primary anesthetic. The remainder (14 cases) were performed awake with cranial regional anesthesia with very light propofol and/or dexmedetomidine intravenous sedation only during noncritical portions such as placement of arterial line and pinning of the pinion system. Intravenous 25 to 50 μg fentanyl in divided doses and 1 g acetaminophen were used for breakthrough discomfort and pain as needed. A scalp block was performed bilaterally with 0.5% ropivacaine. Intravenous lines, an arterial line, and a Foley catheter were then inserted. The patients were placed supine with a skull clamp (Mayfield, Integra LifeSciences, Plainsboro, NJ) and positioned optimally for surgery. Patients were given dexamethasone 10 mg IV once, mannitol 0.25 g/kg, levetiracetam 1,000 mg, and vancomycin 1,000 mg. Neuronavigation (VectorVision, Brainlab, Munich, Germany) was used to plan a scalp incision. The craniotomy exposed the lesion in addition to 2- to 3-cm cortical margins around it for mapping of nearby cortex. Once the bone flap was removed, local anesthetic (0.1% lidocaine with 1:1,000 epinephrine) was administered between the dural leaflets on each side of nerves within the dura. The dura was opened to expose the lesion and was tacked up by 4.0 Nurolons.