Author(s)

Greg Schaublin¹, Romina Shirka¹, Nabil Azar², Callan Broderick³, Jayson Neil^4,5, George R. Lee¹, Kiara Ebinger^1*

¹Real Time Neuromonitoring Associates, Nashville, USA.
²Real Time Tele-Epilepsy Consultants, Nashville, USA.
³Seastnan Medical, LLC, Kansas City, USA.
⁴Midwest Neurosurgery Associates, Kansas City, USA.
⁵Research Medical Center, Kansas City, USA.

Background: We present a compelling case fitting the phenomenon of cortical spreading depression detected by intraoperative neurophysiological monitoring (IONM) following an intraoperative seizure during a craniotomy for revascularization. Cortical spreading depression (CSD, also called cortical spreading depolarization) is a pathophysiological phenomenon whereby a wave of depolarization is thought to propagate across the cerebral cortex, creating a brief period of relative neuronal inactivity. The relationship between CSD and seizures is unclear, although some literature has made a correlation between seizures and a cortical environment conducive to CSD. Methods: Intraoperative somatosensory evoked potentials (SSEPs) and electroencephalography (EEG) were monitored continuously during the craniotomy procedure utilizing standard montages. Electrophysiological data from pre-ictal, ictal, and post-ictal periods were recorded. Results: During the procedure, intraoperative EEG captured a generalized seizure followed by a stepwise decrease in somatosensory evoked potential cortical amplitudes, compelling for the phenomenon of CSD. The subsequent partial recovery of neuronal function was also captured electrophysiologically. Discussion: While CSD is considered controversial in some aspects, intraoperative neurophysiological monitoring allowed for the unique analysis of a case demonstrating a CSD-like phenomenon. To our knowledge, this is the first published example of this phenomenon in which intraoperative neurophysiological monitoring captured a seizure, along with a stepwise subsequent reduction in SSEP cortical amplitudes not explained by other variables.

Cortical Spreading Depression, Electroencephalography, Intraoperative Neurophysiological Monitoring, Seizure

Schaublin, G., Shirka, R., Azar, N., Broderick, C., Neil, J., Lee, G.R. and Ebinger, K. (2024) Possible Cortical Spreading Depression Recorded Intraoperatively Following a Generalized Seizure: Illustrative Case. Neuroscience and Medicine, 15, 119-128. doi: 10.4236/nm.2024.153010.