Feasibility and safety of electrocorticography monitoring after acute brain injury to detect cortical spreading depolarisation, a prospective observational study in a neurological intensive care unit

BACKGROUND: Neurological intensive care units (neuro-ICU) prioritise maintaining homeostasis and monitoring for secondary brain injuries. These injuries can worsen primary lesions, such as those caused by subarachnoid haemorrhage (SAH) or traumatic brain injury (TBI). Cortical spreading depolarisations (SDs) are both markers and mechanisms of secondary brain damage. We evaluated the feasibility and safety of electrocorticography monitoring to identify SD in a neuro-ICU without SD monitoring experience. METHODS: We conducted a single-centre prospective study on adults admitted with either SAH or severe TBI. Each participant's involvement lasted up to 7 days for TBI, and up to 15 days for SAH. The primary endpoint was the availability of a high-quality electrocorticography signal, with or without SD, for ≥12 h per patient. The adverse events of interest were neurological infection, skin infection, cerebrospinal fluid leak, peri-electrode intracranial bleeding, and all-cause mortality. We used subdural Wyler-strip or Spencer-type electrodes, or Intraparenchymal Spencer-type electrodes in patients not requiring surgery. OUTCOMES: A total of 20 patients were included (SAH [n = 12] or a TBI [n = 8]). The primary endpoint was achieved in 19 patients monitored for a median [IQR] of 6 days [4-9]. At least 1 SD was observed in 10 patients (50%; SAH: n = 6/12, TBI: n = 4/8). There was 1 cerebrospinal fluid leakage; 1 local skin infection with a Spencer-type intracortical electrode; and 1 EVD-related ventriculitis with a subdural Spencer-type electrode. CONCLUSIONS: Monitoring SD with electrocorticography is feasible and safe in a neuro-ICU with no prior experience. Further studies are needed to optimise techniques and assess clinical outcomes. STUDY REGISTRATION: ClinicalTrials.gov (NCT04585503). Registered 7 October 2020.