Chapter 19 - Awake Craniotomies for Neoplasms Involving Language Networks

Abstract

The goal of surgery for a brain neoplasm is to maximize the extent of resection while preserving neural functions, i.e., to optimize the onco-functional balance. In tumors involving language networks, awake mapping must be performed in order to detect and to spare both cortical hubs and white matter tracts underlying such complex circuits. The use of intraoperative electrical stimulation allowed a paradigmatic shift in surgical neuro-oncology, namely, to switch from image-guided resection to functional mapping–guided resection. This new concept based upon the investigation of the dynamics of individual language pathways in real time by means of intraoperative cognitive monitoring combined with electrical mapping in awake patients has resulted in a significant increase of surgical indications for lesions located within eloquent areas, with a decrease of permanent morbidity and an improvement of the oncological outcome. This can be conceived only in a connectomal account of language processing, challenging the classical Broca–Wernicke's model. Neurosurgeons should evolve from a rigid localizationist view to a networking organization of neural functioning that makes possible massive resections within so-called inoperable language areas with no persistent postoperative aphasia thanks to the use of cerebral plastic potential. A better understanding of the structural and functional anatomy is crucial because preservation of the language connectome is the key to optimize the benefit/risk ratio of surgery in these eloquent regions.