92 - Intraoperative Mapping and Monitoring for Cortical Resection

Abstract

Successful resection of lesions in eloquent areas of cortex requires diligent intraoperative mapping. Intimate knowledge of surface cortical anatomy and functional neuroimaging are useful to further delineate the relationship between lesions and eloquent cortex. This chapter outlines the critical steps necessary to perform adequate electrocortical mapping and resection of lesions in eloquent areas of cortex. Thorough patient counseling prior to operative intervention in awake mapping greatly aids in successful surgery. Goals and details of the surgery should be coordinated with the anesthesia team to optimize patient comfort and ensure minimal interruption with neurostimulation responses. Depending on the location of the lesion of interest, somatosensory evoked potentials can be used to localize the central sulcus. Further stimulation and monitoring can identify the extent of the sensorimotor area. In the instance of motor or language mapping, performance of an awake craniotomy is required, with monopolar or bipolar motor and language stimulation mapping in serial patches of cortex. Care should be taken to preserve identified areas of language and eloquence during resection. In this chapter we further discuss the senior author’s technique and experience with cortical mapping and resection of lesions in eloquent cortex.