Invasive monitoring of electrical activity of the brain in patients with acute massive subarachnoid hemorrhage due to cerebral aneurysm rupture

Background . Invasive monitoring of electrical activity of the brain (invasive electroencephalography (EEG)) can have a number of advantages in diagnosis of early damage and delayed ischemia of the brain during cerebral vascular spasm due to its higher sensitivity and lower number of artifacts compared to noninvasive (scalp) monitoring. However, there are no standards of invasive electrode placement and registration of invasive recording. We present clinical experience of invasive prolonged EEG monitoring in patients during the acute period of cerebral aneurysm rupture. Aim . To develop technique of invasive EEG monitoring in patients with cerebral aneurysm rupture and to evaluate characteristics of the observed electrographic changes. Materials and methods . Series of clinical observations are presented: 6 patients who were operated on in the acute period of nontraumatic subarachnoid hemorrhage and who underwent simultaneous scalp and invasive EEG monitoring. Results . Pathologic changes observed during EEG correlated with development of areas of cerebral ischemia. Changes registered during invasive EEG were more pronounced and appeared earlier than during scalp monitoring. Conclusion . Informativity of invasive EEG monitoring in diagnosis of delayed cerebral ischemia and seizureless epileptiform activity is higher compared to scalp EEG monitoring.