Physiological Assessments of Subarachnoid Hemorrhage

Brain injury after subarachnoid hemorrhage (SAH) shows a multiphasic evolution with a global ischemic insult at the time of the initial hemorrhage, complications of early surgical or endovascular aneurism treatment thereafter, followed by a time period with a high risk for secondary focal ischemic events. This so-called delayed cerebral ischemia (DCI) peaks around day 7 after the initial hemorrhage and is a multiphasic condition by itself as it often shows a gradually progressing, waxing, and waning pattern before the neurological deficits become permanent. This chapter provides an introduction to Chaps. 23–29 in which a number of methods are described to study the pathophysiological basis of different components that contribute to brain damage during and following SAH.