Cortical spreading depression occurs during elective neurosurgical procedures

Area of Science:

• Neurosurgery
• Neurophysiology
• Neurology

Background:

• Cortical spreading depression (CSD) is a wave of neuronal and glial depolarization observed after brain injury.
• Neurosurgical manipulation may induce CSD, potentially contributing to secondary injury.
• Intraoperative monitoring for CSD is not standard practice.

Purpose of the Study:

• To report initial experience with direct intraoperative electrocorticography (ECoG) monitoring for CSD during elective craniotomy.
• To evaluate the feasibility and challenges of detecting CSD in the operating room environment.

Main Methods:

• Prospective enrollment of patients undergoing elective craniotomy for supratentorial lesions (>2-hour duration).
• Intraoperative ECoG monitoring using a 1x6 platinum electrode array and AC or DC-coupled amplifiers.
• Data analysis focused on detecting slow potential changes and suppressed high-frequency ECoG activity consistent with CSD.

Main Results:

• CSD was detected in 1 of 11 patients (2 definite events) and suspicious events were noted in 4 others.
• DC-coupled amplifiers provided more stable signals than AC-coupled systems.
• Operating room environment presented challenges, including cautery artifact and noise, compared to postoperative ICU monitoring.

Conclusions:

• CSD can occur during elective neurosurgery, potentially in distant brain regions.
• Intraoperative ECoG monitoring, particularly with DC-coupled amplifiers, can detect CSD despite surgical artifacts.
• Further research into modifying anesthetic regimens to reduce CSD occurrence may enhance neurosurgical safety.