EARLY DETECTION OF VASOSPASM AFTER ACUTE SUBARACHNOID HEMORRHAGE USING CONTINUOUS EEG ICU MONITORING

The neurologic morbidity of delayed ischemic deficits from vasospasm f ollowing aneurysmal subarachnoid hemorrhage (SAH) continues to be the most debilitating complication from this devastating illness. Neurolog ic critical care is focused on recognition and treatment of these seco ndary insults but often the treatment is withheld until an irreversibl e deficit becomes manifest. Continuous EEG (cEEG) monitoring provides a unique potential to recognize early secondary insults and offers an opportunity for early intervention. We studied 32 SAH patients using c EEG and trending of the quantitative measure, relative alpha (RA), to determine if reductions in RA variability occurred with documented vas ospasm. In 19/19 patients with angiographically documented vasospasm, we found that RA variability was decreased by a mean of two grades and improved with resolution of vasospasm. In 10/19 this reduction in RA variability preceded the diagnosis of vasospasm by a mean of 2.9 days (SD 1.73). The positive predictive and negative predictive values are 76% and 100%, respectively. Non-diagnostic clinical signs at the time of RA variability reduction and vasospasm were present in 12/19 patien ts. Thus decreased RA variability is able to provide early detection o f neurologic complications such as vasospasm in patients before clear clinical symptoms and signs occur. (C) 1997 Elsevier Science Ireland L td.