To explore whether the use of continuous EEG monitoring in aneurysmal subarachnoid hemorrhage leads to differences in clinical outcomes and healthcare costs.

Delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH) substantially contributes to morbidity and mortality.  Early detection is critical to avoid secondary brain injury and remains a major challenge particularly in obtunded patients. Continuous EEG monitoring can predict early DCI with good sensitivity and specificity.

This is a retrospective chart review of adult patients with non-traumatic aSAH at a tertiary academic medical center. 18 subjects who underwent continuous EEG monitoring under a dedicated protocol for DCI detection were compared to a matched cohort of 18 controls prior to protocol implementation. Clinical outcomes were determined through an analysis of survival rate, modified Rankin Score (mRS), focal neurologic deficits (FND) and radiographic ischemic findings directly attributable to DCI. The total number of imaging studies, interventional procedures, and length of hospitalization was recorded to estimate overall cost.

An equal number of deaths was observed in both groups (2/18), however, in contrast to the EEG group, the cause of death in the control group was directly attributable to complications of DCI. The discharge mRS and radiographic infarction rates were higher in the control group (3.1 vs 2.8 [0.302] and 50% vs 37.5%, respectively). The total number of imaging studies and digital subtraction angiography performed was lower in the EEG group (mean 8.7 vs 9.8 [0.161] and 38.9% vs 61.1%, respectively). Subjects in the EEG group had a shorter length of ICU and hospital stay (mean 13.7 vs 17.4 [0.012] and 18.6 vs 22.8 [0.04], respectively).

Continuous EEG monitoring may lead to improved short-term clinical outcomes and a reduction in utilization of health care resources in aSAH. Further analyses of larger patient populations and long-term outcomes is recommended to robustly validate these findings.