PO75A STANDARDISED ANATOMICAL AND FUNCTIONAL CLASSIFICATION OF CORTICAL AND SUBCORTICAL BRAIN FUNCTION FOR INTRAOPERATIVE MAPPING DURING AWAKE CRANIOTOMY

Abstract

INTRODUCTION: Extent of resection for intrinsic brain tumors has been established as an important determinant of survival Intraoperative stimulation brain mapping enables significantly higher rates of GTR. Additionally, there has been a 4-fold increase publications related to awake craniotomy in the past decade (45% increase in past 5 years). However there are limited publications worldwide (n <300), which report a range of practices for assessing cortical function. A standardised approach is lacking, which may be a contributor. We propose a unified approach for intraoperative cognitive assessment based on validated neurocognitive practice. This will provide the field with a state-of-the-art approach to awake craniotomy. METHOD: We propose a battery of tests, using 7 lobes of the brain (frontal, parietal, temporal, occipital, insular, central, cingulate). Further fractionation of cognitive function is considered, using major cortical surface markings, and subcortical tracts (i.e. uncinate fasiciulus, arcuate fasiculus, superior longitudinal fasciculus etc.). Criteria for use include ease of delivery, replicability, lack of routine neuropsychology involvement and a tablet-base. RESULTS: Based on institutional experience over 24 months, anatomical dissection, and peer-reviewed cognitive neuroscientific findings of functional specialisation and network connectivity, a whole brain map has been designed with functional subdivision, and corresponding tasks with measurable behavioural outputs. CONCLUSION: The proposed classification will need consensus among surgeons and the neuroscience community establish a validated system with non-significant inter-observer variability and optimal functional outcomes.