Is non-awake surgery for supratentorial adult low-grade glioma treatment still feasible?

In this short review, the author performs a database search, summarizes, and discusses studies that provide information on the need to perform awake surgery to preserve quality of life/return to work of adult patients who undergo resection for a supratentorial low-grade glioma (LGG). Based upon the currently available data, the author concludes that in LGG, patients with no or only mild deficits at diagnosis, non-awake surgery can no longer be achieved. Indeed, awake craniotomy with intrasurgical electrical mapping has resulted in an increase of the extent of resection and overall survival in LGG. Furthermore, in order to resume a normal familial, social, and professional life, LGG patients with a prolonged survival expectancy have to benefit not only from language mapping when the tumor involves the left "dominant" hemisphere, but also from intraoperative mapping of sensorimotor, visuospatial, higher cognitive, and emotional functions under local anesthesia, even for gliomas situated within presumed "non-language" areas such as the right "non-dominant" hemisphere. In other words, the ultimate goal is to map the functional connectome for each patient in order to perform the resection up to the eloquent networks and then to optimize the onco-functional balance of LGG surgery. To this end, an objective neuropsychological assessment has to be achieved in a more systematic manner before and after resection. Early postoperative cognitive rehabilitation is also recommended, whenever needed.