Repetitive cortical spreading depolarizations in a case of severe brain trauma

Cortical spreading depolarizations (CSD) are waves of mass tissue depolarization that mediate progressive development of cortical infarction in animal models and occur in approximately 50% of patients with acute brain injury. Here we performed multi-modal cerebral monitoring to investigate pathologies associated with CSD occurrence in a case of severe traumatic brain injury.

A 20 years old male suffering severe traumatic brain injury from a fall had extensive frontal subdural and intraparenchymal hemorrhage with mass effect. Craniectomy was performed for hematoma evacuation and decompression.

During surgery, a subdural electrocorticography (ECoG) electrode strip, along with microdialysis and PtiO2 probes, was placed beside injured cortex for CSD monitoring. Within 13-81 hours post-injury, 34 CSD occurred. CSD incidence increased during spontaneous hyperthermia and decreased during induced normothermia. Periods of CSD activity were also associated with low brain glucose (<0.10 mmol/l), elevated glutamate (>40 mmol/l) and lactate/pyruvate (>40), and PtiO2<10 mmHg. CSD caused progressive deterioration of ECoG activity only in regions with infarction at follow-up on day 27.

Repetitive mass tissue depolarizations accompanied a negative course of hemorrhagic lesion progression in the presence of ischemic conditions after traumatic brain injury. Whether as cause or effect, CSD may represent an inherent component of progressive metabolic failure leading to tissue death, and temperature appears to be an important factor influencing their occurrence. Continuous ECoG is a valuable tool for monitoring subclinical events such as CSD and seizures and for translational research in acute brain injury mechanisms and therapeutics.