Electrocorticographic frequency alteration mapping of speech cortex during an awake craniotomy: case report

Area of Science:

• Neuroscience
• Neurosurgery
• Medical Imaging

Background:

• Traditional electrocortical stimulation (ECS) for eloquent cortex localization is time-consuming and carries a risk of afterdischarges.
• Electrocorticographic frequency alteration mapping (EFAM) provides a passive, parallel investigation of cortical sites, saving time and avoiding afterdischarges.

Observation:

• A 61-year-old male with a temporal-parietal tumor underwent awake craniotomy for language mapping.
• Electrocorticographic signals were recorded during speech tasks using a 32-contact electrode array.
• Spectral analysis identified cortical areas active during speech.

Findings:

• EFAM was successfully implemented during an awake craniotomy.
• EFAM demonstrated good concordance with ECS mapping, identifying 3 out of 4 ECS-identified sites.
• Two sites showed statistically significant correlation, and one showed qualitative agreement.

Implications:

• EFAM is a promising adjunct tool for intraoperative mapping, offering time savings and eliminating the risk of afterdischarges.
• Cortical signals from EFAM can aid in localizing eloquent regions near tumors.
• This technique holds potential for improving surgical outcomes in neuro-oncology and epilepsy surgery.