Subcortical functional cognitive hubs assessed by intraoperative neuropsychological protocol in awake surgery

• Subcortical monopolar stimulation produces significant findings requiring careful analysis. • Rigorous selection of intraoperative neuropsychological tasks is essential in awake surgery. • Awake surgery offers key insights into the frontal lobe’s complex functional organization. Awake patient surgery for glioma resection aims to achieve the widest possible resection while ensuring that postoperative deficits do not compromise the patient’s quality of life. This report presents the case of a 40-year-old right-handed man with a left frontal lobe lesion consistent with a probable low-grade glial tumour. A preoperative neuropsychological assessment was performed to establish the patient’s baseline cognitive functioning and to plan a comprehensive, individualised intraoperative neuropsychological protocol. Bipolar cortical stimulation and deep monopolar stimulation of the white matter were employed. During bipolar cortical stimulation, three language-blocking sites were identified at the posteroinferior margin of the lesion, corresponding to Broca’s area. In addition, involuntary directional eye movements contralateral to the stimulated area were observed, suggesting involvement of the frontal eye field region. Using neuropsychological tasks in combination with deep monopolar white matter stimulation, alterations in motor sequencing, autobiographical memory, naming, verbal automatisms, and calculation were recorded. These alterations occurred when different points of the deep white matter were stimulated, particularly in regions between the supplementary motor area and the precentral gyrus. Overall, these findings suggest that complex and flexible cognitive, behavioural, and emotional functions can be identified during awake surgery. Our work highlights the need to develop intraoperative tasks that enhance patient safety during the neurosurgical procedure while minimising false-positive findings. Furthermore, white matter stimulation provides valuable insight into the interconnected network systems that support brain function. An additional consideration is the optimisation of direct electrical stimulation parameters, which may further improve the reliability of intraoperative mapping.