Introduction: The perirolandic motor area has been reported to have a higher incidence of intraoperative seizures (IOS) during awake craniotomies than any other cortical region. This study evaluates the role of intraoperative seizures on neurological outcome and extent of tumor resection (EOR) in the perirolandic region, as well as analyzes the efficacy of cortical mapping in this region.

Methods: Thirty-nine patients who underwent an awake craniotomy for a perirolandic glioma by a single-surgeon were retrospectively evaluated for the incidence of IOS and a univariate analysis of preoperative risks, perioperative complications, and EOR between patients with no intraoperative seizure (nIOS) and patients with IOS was conducted. To study neurological outcome in awake craniotomies after perirolandic tumor resection with cortical mapping, a comparative univariate analysis on 28 of the patients who had positive cortical mapping and 11 patients that had negative mapping was conducted.

Results: We found an incidence of IOS at 12.8% during cortical mapping for awake craniotomies in the perirolandic area, none of which caused an aborted case. Intraoperative seizure patients had a significantly smaller EOR (59.1%) compared to nIOS patients (87.9%) (p=0.043). The length of hospitalization in the IOS patients was also longer (12.4 ± 2.0 days) compared to the nIOS patients (3.7 ± 0.4 days) (p=0.011). Positive cortical mapping had more postoperative seizures (35.7%) compared to negative mapping (0%) (p=0.022). New postoperative motor deficits were also more common in positive mapping patients (60.7%) versus negative mapping patients (18.2%) (p=0.017).

Conclusions: Intraoperative seizures in awake craniotomies for perirolandic gliomas can limit the extent of tumor resection and cause significant increases in the length of hospitalizations. Craniotomies that limit cortical exposure for perirolandic gliomas in conjunction with negative mapping of eloquent motor regions, allow for aggressive tumor resection with low postoperative motor deficits and seizures.

Patient Care: This study evaluates intraoperative seizures during awake craniotomies and identifies surgical technique and brain mapping methods that can help reduce the amount of intraoperative seizures patients' experience during awake craniotomies for perirolandic gliomas.

Learning Objectives: 1) To identify the risks and complications associated with awake cranitiomies for perirolandic region lesions 2) To understand the role of cortical mapping with neurological outcome in perirolandic gliomas 3) To understand the effects of intraoperative seizures and cortical mapping on extent of resection

References: 1. Boetto J, Bertram L, Moulinie G, Herbet G, Moritz-Gasser S, Duffau H. Low rate of intraoperative seizures during awake craniotomy in a prospective cohort with 374 supratentorial brain lesions: Electrocorticography is not mandatory. World Neurosurg. 2015. 2. Duffau H. Lessons from brain mapping in surgery for low-grade glioma: Insights into associations between tumour and brain plasticity. Lancet Neurol. 2005;4(8):476-486. 3. Lubrano V, Draper L, Roux FE. What makes surgical tumor resection feasible in broca's area? insights into intraoperative brain mapping. Neurosurgery. 2010;66(5):868-75; discussion 875. 4. Skirboll SS, Ojemann GA, Berger MS, Lettich E, Winn HR. Functional cortex and subcortical white matter located within gliomas. Neurosurgery. 1996;38(4):678-84; discussion 684-5. 5. Ojemann JG, Miller JW, Silbergeld DL. Preserved function in brain invaded by tumor. Neurosurgery. 1996;39(2):253-8; discussion 258-9. 6. Bookheimer S. Pre-surgical language mapping with functional magnetic resonance imaging. Neuropsychol Rev. 2007;17(2):145-155. 7. Mate A, Lidzba K, Hauser TK, Staudt M, Wilke M. A "one size fits all" approach to language fMRI: Increasing specificity and applicability by adding a self-paced component. Exp Brain Res. 2016;234(3):673-684. 8. Reithmeier T, Krammer M, Gumprecht H, Gerstner W, Lumenta CB. Neuronavigation combined with electrophysiological monitoring for surgery of lesions in eloquent brain areas in 42 cases: A retrospective comparison of the neurological outcome and the quality of resection with a control group with similar lesions. Minim Invasive Neurosurg. 2003;46(2):65-71. 9. Kim SS, McCutcheon IE, Suki D, Weinberg JS, Sawaya R, Lang FF, Ferson D, Heimberger AB, DeMonte F, Prabhu SS. Awake craniotomy for brain tumors near eloquent cortex: Correlation of intraoperative cortical mapping with neurological outcomes in 309 consecutive patients. Neurosurgery. 2009;64(5):836-45; discussion 345-6. 10. Gonen T, Grossman R, Sitt R, Nossek E, Yanaki R, Cagnano E, Korn A, Hayat D, Ram Z. Tumor location and IDH1 mutation may predict intraoperative seizures during awake craniotomy. J Neurosurg. 2014;121(5):1133-1138. 11. Nossek E, Matot I, Shahar T, Barzilai O, Rapoport Y, Gonen T, Sela G, Korn A, Hayat D, Ram Z. Failed awake craniotomy: A retrospective analysis in 424 patients undergoing craniotomy for brain tumor. J Neurosurg. 2013;118(2):243-249. 12. Nossek E, Matot I, Shahar T, Barzilai O, Rapoport Y, Gonen T, Sela G, Grossman R, Korn A, Hayat D, Ram Z. Intraoperative seizures during awake craniotomy: Incidence and consequences: Analysis of 477 patients. Neurosurgery. 2013;73(1):135-40; discussion 140. 13. Serletis D, Bernstein M. Prospective study of awake craniotomy used routinely and nonselectively for supratentorial tumors. J Neurosurg. 2007;107(1):1-6. 14. Hervey-Jumper SL, Li J, Lau D, Molinaro AM, Perry DW, Meng L, Berger MS. Awake craniotomy to maximize glioma resection: Methods and technical nuances over a 27-year period. J Neurosurg. 2015;123(2):325-339. 15. Berger MS. Functional mapping-guided resection of low-grade gliomas. Clin Neurosurg. 1995;42:437-452. 16. Berger MS, Rostomily RC. Low grade gliomas: Functional mapping resection strategies, extent of resection, and outcome. J Neurooncol. 1997;34(1):85-101. 17. Black PM, Ronner SF. Cortical mapping for defining the limits of tumor resection. Neurosurgery. 1987;20(6):914-919. 18. Ciric I, Ammirati M, Vick N, Mikhael M. Supratentorial gliomas: Surgical considerations and immediate postoperative results. gross total resection versus partial resection. Neurosurgery. 1987;21(1):21-26. 19. Haglund MM, Berger MS, Shamseldin M, Lettich E, Ojemann GA. Cortical localization of temporal lobe language sites in patients with gliomas. Neurosurgery. 1994;34(4):567-76; discussion 576. 20. Berger MS, Kincaid J, Ojemann GA, Lettich E. Brain mapping techniques to maximize resection, safety, and seizure control in children with brain tumors. Neurosurgery. 1989;25(5):786-792. 21. Matz PG, Cobbs C, Berger MS. Intraoperative cortical mapping as a guide to the surgical resection of gliomas. J Neurooncol. 1999;42(3):233-245. 22. Ojemann G, Ojemann J, Lettich E, Berger M. Cortical language localization in left, dominant hemisphere. an electrical stimulation mapping investigation in 117 patients. 1989. J Neurosurg. 2008;108(2):411-421. 23. Ojemann GA. Individual variability in cortical localization of language. J Neurosurg. 1979;50(2):164-169. 24. Quinones-Hinojosa A, Ojemann SG, Sanai N, Dillon WP, Berger MS. Preoperative correlation of intraoperative cortical mapping with magnetic resonance imaging landmarks to predict localization of the broca area. J Neurosurg. 2003;99(2):311-318. 25. Walker JA, Quinones-Hinojosa A, Berger MS. Intraoperative speech mapping in 17 bilingual patients undergoing resection of a mass lesion. Neurosurgery. 2004;54(1):113-7; discussion 118. 26. Chaichana KL, Jusue-Torres I, Navarro-Ramirez R, Raza SM, Pascual-Gallego M, Ibrahim A, Hernandez-Hermann M, Gomez L, Ye X, Weingart JD, Olivi A, Blakeley J, Gallia GL, Lim M, Brem H, Quinones-Hinojosa A. Establishing percent resection and residual volume thresholds affecting survival and recurrence for patients with newly diagnosed intracranial glioblastoma. Neuro Oncol. 2014;16(1):113-122. 27. Chaichana KL, Jusue-Torres I, Lemos AM, Gokaslan A, Cabrera-Aldana EE, Ashary A, Olivi A, Quinones-Hinojosa A. The butterfly effect on glioblastoma: Is volumetric extent of resection more effective than biopsy for these tumors? J Neurooncol. 2014;120(3):625-634. 28. Chaichana KL, Cabrera-Aldana EE, Jusue-Torres I, Wijesekera O, Olivi A, Rahman M, Quinones-Hinojosa A. When gross total resection of a glioblastoma is possible, how much resection should be achieved? World Neurosurg. 2014;82(1-2):e257-65. 29. Skardelly M, Brendle E, Noell S, Behling F, Wuttke TV, Schittenhelm J, Bisdas S, Meisner C, Rona S, Tatagiba MS, Tabatabai G. Predictors of preoperative and early postoperative seizures in patients with intra-axial primary and metastatic brain tumors: A retrospective observational single center study. Ann Neurol. 2015;78(6):917-928. 30. Sartorius CJ, Wright G. Intraoperative brain mapping in a community setting--technical considerations. Surg Neurol. 1997;47(4):380-388. 31. Sacko O, Lauwers-Cances V, Brauge D, Sesay M, Brenner A, Roux FE. Awake craniotomy vs surgery under general anesthesia for resection of supratentorial lesions. Neurosurgery. 2011;68(5):1192-8; discussion 1198-9. 32. Szelenyi A, Bello L, Duffau H, Fava E, Feigl GC, Galanda M, Neuloh G, Signorelli F, Sala F, Workgroup for Intraoperative Management in Low-Grade Glioma Surgery within the European Low-Grade Glioma Network. Intraoperative electrical stimulation in awake craniotomy: Methodological aspects of current practice. Neurosurg Focus. 2010;28(2):E7. 33. Berger MS, Deliganis AV, Dobbins J, Keles GE. The effect of extent of resection on recurrence in patients with low grade cerebral hemisphere gliomas. Cancer. 1994;74(6):1784-1791. 34. Keles GE, Anderson B, Berger MS. The effect of extent of resection on time to tumor progression and survival in patients with glioblastoma multiforme of the cerebral hemisphere. Surg Neurol. 1999;52(4):371-379. 35. Keles GE, Lamborn KR, Berger MS. Low-grade hemispheric gliomas in adults: A critical review of extent of resection as a factor influencing outcome. J Neurosurg. 2001;95(5):735-745. 36. Lacroix M, Abi-Said D, Fourney DR, Gokaslan ZL, Shi W, DeMonte F, Lang FF, McCutcheon IE, Hassenbusch SJ, Holland E, Hess K, Michael C, Miller D, Sawaya R. A multivariate analysis of 416 patients with glioblastoma multiforme: Prognosis, extent of resection, and survival. J Neurosurg. 2001;95(2):190-198. 37. Berger MS, Ojemann GA, Lettich E. Neurophysiological monitoring during astrocytoma surgery. Neurosurg Clin N Am. 1990;1(1):65-80. 38. Berger MS. Surgery of low-grade gliomas--technical aspects. Clin Neurosurg. 1997;44:161-180. 39. King RB, Schell GR. Cortical localization and monitoring during cerebral operations. J Neurosurg. 1987;67(2):210-219. 40. Sanai N, Mirzadeh Z, Berger MS. Functional outcome after language mapping for glioma resection. N Engl J Med. 2008;358(1):18-27. 41. Sanai N, Chang S, Berger MS. Low-grade gliomas in adults. J Neurosurg. 2011;115(5):948-965. 42. Martino J, Gomez E, Bilbao JL, Duenas JC, Vazquez-Barquero A. Cost-utility of maximal safe resection of WHO grade II gliomas within eloquent areas. Acta Neurochir (Wien). 2013;155(1):41-50. 43. Zakhary R, Keles GE, Berger MS. Intraoperative imaging techniques in the treatment of brain tumors. Curr Opin Oncol. 1999;11(3):152-156.