Intraoperative mapping of executive function using electrocorticography for patients with low-grade gliomas.


Type
Article
Change log
Authors
Assem, Moataz 
Coelho, Pedro 
Romero-Garcia, Rafael 
Owen, Mallory 
Abstract

BACKGROUND: Intraoperative functional mapping with direct electrical stimulation during awake surgery for patients with diffuse low-grade glioma has been used in recent years to optimize the balance between surgical resection and quality of life following surgery. Mapping of executive functions is particularly challenging because of their complex nature, with only a handful of reports published so far. Here, we propose the recording of neural activity directly from the surface of the brain using electrocorticography to map executive functions and demonstrate its feasibility and potential utility. METHODS: To track a neural signature of executive function, we recorded neural activity using electrocorticography during awake surgery from the frontal cortex of three patients judged to have an appearance of diffuse low-grade glioma. Based on existing functional magnetic resonance imaging (fMRI) evidence from healthy participants for the recruitment of areas associated with executive function with increased task demands, we employed a task difficulty manipulation in two counting tasks performed intraoperatively. Following surgery, the data were extracted and analyzed offline to identify increases in broadband high-gamma power with increased task difficulty, equivalent to fMRI findings, as a signature of activity related to executive function. RESULTS: All three patients performed the tasks well. Data were recorded from five electrode strips, resulting in data from 15 channels overall. Eleven out of the 15 channels (73.3%) showed significant increases in high-gamma power with increased task difficulty, 26.6% of the channels (4/15) showed no change in power, and none of the channels showed power decrease. High-gamma power increases with increased task difficulty were more likely in areas that are within the canonical frontoparietal network template. CONCLUSIONS: These results are the first step toward developing electrocorticography as a tool for mapping of executive function complementarily to direct electrical stimulation to guide resection. Further studies are required to establish this approach for clinical use.

Description
Keywords
Awake neurosurgery, Brain tumor, Electrocorticography (ECOG), Executive function, Functional mapping, Intraoperative, Low-grade glioma, Patients, Adult, Brain Mapping, Brain Neoplasms, Cognition, Electric Stimulation, Electrocorticography, Executive Function, Female, Gamma Rhythm, Glioma, Humans, Intraoperative Care, Magnetic Resonance Imaging, Male, Middle Aged, Quality of Life
Journal Title
Acta Neurochir (Wien)
Conference Name
Journal ISSN
0001-6268
0942-0940
Volume Title
163
Publisher
Springer Science and Business Media LLC
Rights
All rights reserved
Sponsorship
Cambridge Commonwealth, European & International Trust (unknown)
Medical Research Council (MC_UU_00005/6)