Feasibility Study of Cortical Recording Depolarizations in Brain-injured Patients, and Their Use as Biomarkers of New Lesions.

The progression of brain lesions after severe head trauma or subarachnoid hemorrhage results from extra cranial aggression which is well controlled in intensive care and intracranial aggression which is less well known and therefore less well managed. The detection of events that can generate new lesions from intracranial monitoring is limited and late once the lesions are irreversible. Invasive cortical depolarizations (SD) can be observed using cortical electrodes and an acquisition system having access to the usually filtered DC signal (0 to 1 Hz). SD are observed at the onset of a new attack of the cortex and spread widely away from the site of aggression. During their propagation, SD generate a significant metabolic demand, and can cause ischemic injury, particularly after meningeal or post-traumatic hemorrhage. SDs are therefore both a marker of new lesion and a mechanism of progression of primary lesions. Yet this type of monitoring is only performed in some expert centers around the world. The analysis of the feasibility and safety of the placement of cortical electrodes in this indication is therefore an essential step to study the clinical benefit of individualized management on the basis of this monitoring.