There is increasing evidence that the extent of tumor removal in low-grade glioma surgery is related to patient survival time. Thus, the goal of resecting the largest amount of tumor possible without leading to permanent neurological sequelae is a challenge for the neurosurgeon. Electrical stimulation of the brain to detect cortical and axonal areas involved in motor, language, and cognitive function and located within the tumor or along its boundaries has become an essential tool in combination with awake craniotomy. Based on a literature review, discussions within the European Low-Grade Glioma Group, and illustrative clinical experience, the authors of this paper provide an overview for neurosurgeons, neurophysiologists, linguists, and anesthesiologists as well as those new to the field about the stimulation techniques currently being used for mapping sensorimotor, language, and cognitive function in awake surgery for low-grade glioma. The paper is intended to help the understanding of these techniques and facilitate a comparison of results between users.

Purpose: To evaluate factors influencing clinical and radiological outcome of extended endoscopic endonasal transtuberculum/transplanum approach (EEA-TTP) for giant pituitary adenomas (GPAs). Methods: We recruited prospectively all consecutive GPAs patients undergoing EEA-TTP between 2015 and 2019 in 5 neurosurgical centers. Preoperative clinical and radiologic features, visual and hormonal outcomes, extent of resection (EoR), complications and recurrence rates were recorded and analyzed. Results: Of 1169 patients treated for pituitary adenoma, 96 (8.2%) had GPAs. Seventy-eight (81.2%) patients had visual impairment, 12 (12.5%) had headaches, 3 (3.1%) had drowsiness due to hydrocephalus, and 53 (55.2%) had anterior pituitary insufficiency. EoR was gross or near-total in 46 (47.9%) and subtotal in 50 (52.1%) patients. Incomplete resection was associated with lateral suprasellar, intraventricular and/or cavernous sinus extension and with firm/fibrous consistence. At the last follow-up, all but one patient (77, 98.7%) with visual deficits improved. Headache improved in 8 (88.9%) and anterior pituitary function recovered in 27 (50.9%) patients. Recurrence rate was 16.7%, with 32 months mean recurrence-free survival. Conclusions: EEA-TTP is a valid option for GPAs and seems to provide better outcomes, lower rate of complications and higher EoR compared to one- or multi-stage microscopic, non-extended endoscopic transsphenoidal, and transcranial resections.

BACKGROUND:. The management of gliomas is based on precise histologic diagnosis. The tumor tissue can be obtained during open surgery or via stereotact