Awake Craniotomy in Arteriovenous Malformation Surgery: The Usefulness of Cortical and Subcortical Mapping of Language Function in Selected Patients

Chinese Cerebrovascular Neurosurgery Society and Chinese Interventional & Hybrid Operation Society, of Chinese Stroke Association Clinical Practice Guidelines for Management of Brain Arteriovenous Malformations in Eloquent Areas

“…Currently, the mapping through DES was usually performed on basis of fMRI ( 173 , 174 ). Besides the direct stimulations to the cortex, Gamble et al ( 175 ) revealed the value of subcortical stimulation on identifying subcortical eloquent structures. Concluding the proposals of current studies, the electrical cortical/subcortical stimulation was recommended if the lesion (1) adjacent to eloquence on fMRI (not distancing nor overlaying); (2) in large sizes and high SM grades; (3) with diffusive nidus.…”

“…The DES under local anesthesia had become popular in recent years. It was capable of mapping not only essential cortico-subcortical areas of motricity, but also areas of sensitivity, language, and even memory ( 174 , 175 ). It had been proved to be effective in helping identifying eloquence and preserving neural functions ( 171 , 176 ).…”

Awake Surgery for Arteriovenous Malformations (AVM) in Eloquent Area: Risk and Outcome Analysis in the Most Complete Case-Collection

“…Neurologic sequelae of the treatment of brain AVMs were extensively investigated, and depending on the S-M grade [19 , 20]. The concept of eloquent proximity as a signi cant factor in surgical morbidity and mortality is supported by several AVM series and there is a strong correlation between the eloquence of the brain tissue adjacent to an AVM and the postoperative development of a new neurological de cit [11,22]. Predicting postoperative neurologic de cit or even the feasibility of surgery is therefore di cult.…”

“…Furthermore, this new tool forced clinicians to reconsider anatomically based assumptions about eloquence and thus, actual S-M. fMRI maps utilized in surgical planning are generated from BOLD signals derived from the difference between oxyhemoglobin and deoxyhemoglobin levels of blood by location, thus giving us a proxy for cortical activity in areas where oxygen is being extracted at a higher rate [13]. This may account for inconsistent correlations between fMRI and intraoperative language mapping that have been reported in tumors, epilepsy, and mixed series including AVMs [11,16].…”

“…Pre-operatively functional imaging can facilitate the localization of the eloquent areas, but recent studies have discussed the usefulness and reliability of functional magnetic resonance imaging (fMRI) in the anatomic localization of language function [5,19]. There were reports of misleading results and these were associated with the reorganization of eloquent areas in the presence of AVMs [11] . Awake craniotomy for AVM surgery is not a common practice, and this procedure requires an expert team of anaesthetists, neurosurgeons and neuropsychologists who routinely perform awake cranial procedures.…”