Awake Craniotomy with Cortical and Subcortical Speech Mapping for Supramarginal Cavernoma Resection.

Abstract

Awake craniotomy allows mapping of eloquent brain regions and monitoring neurocognitive functioning intraoperatively to maximize extent of resection and minimize cognitive morbidity.¹^,² During resection of cavernous malformations in eloquent areas, intraoperative cognitive monitoring can also allow for safer maximal excision of the hemosiderin ring, which is correlated with improved seizure-free outcome.³^,⁴ We present the case of a 33-year-old right-handed male with a new-onset seizure who presented to his local emergency department after experiencing visual hallucinations before losing consciousness. Computed tomography scan of the head revealed a calcified lesion in the left temporal/parietal area. Presurgical workup revealed left hemispheric language dominance and language activation within the overlying supramarginal gyrus representing phonologic working memory on functional magnetic resonance imaging.⁵ Diffusion tensor imaging identified the arcuate fasciculus and lateral portion of the superior longitudinal fasciculus to be intimately associated with the deep margin of the lesion.⁶ After consent was obtained, we performed an awake craniotomy and resection of the lesion through a transsulcal approach, with eloquent cortical mapping using a novel high-density circular grid,⁷^,⁸ as well as subcortical stimulation/mapping and continuous intraoperative cognitive monitoring using multiple language paradigms; the patient was baselined on these paradigms preoperatively (Video 1). Several phonologic/paraphasic errors were made during resection of the hemosiderin ring, likely related to mechanical manipulation. The patient was discharged to home on postoperative day 4 with outpatient speech therapy for speech hesitancy. At 1-week postoperative testing, language skills were considered within normal limits.