We have developed a novel device and procedure that allows the placement of commercially available intracranial electrodes into the subdural space and onto the cortical surface at the Neurocritical Care Unit bedside. The procedure is performed with a standard cranial access kit and in the same general workflow as other common bedside procedures. Here, we report our results validating the device by target users (Neurosurgical housestaff) in a human cadaveric model.

Subdural electrode monitoring has been utilized for decades to identify seizure onset zones and perform cortical mapping during surgical resections. Traditionally, craniotomy or craniectomy is required for subdural electrode placement. Recently, cortical spreading depolarizations (CSDs) have emerged as a promising therapeutic target in patients with diverse injurious conditions such as traumatic brain injury, stroke, aneurysmal subarachnoid hemorrhage and intracranial hemorrhage. Given subdural electrodes are the gold standard for detecting CSDs, their detection has been limited to patients undergoing craniotomy or craniectomy where electrodes can be placed. For example, the 'INDICT' and 'CSD After Severe TBI' trials both enroll only patients undergoing craniotomy or craniectomy for their underlying pathology and they represent a minority of those with pathology concerning for CSD development.

The target users (Neurosurgical housestaff) were all able to successfully perform the procedure and provided overwhelmingly positive feedback regarding the usability of the device and ease of the procedure. 

By reducing the invasiveness of subdural electrode monitoring to comparability with standard forms of neuromonitoring, this device and procedure holds promise to increase the detection of CSDs in the Neurocritical Care Unit facilitating both research into their significance and identification of patients who would benefit from therapeutic intervention.