Acute Physiologic and Morphologic Assessment Following Subarachnoid Hemorrhage - Animal Models of Acute Neurological Injuries: Injury and Mechanistic Assessments - page 290

Chapter 20
Acute Physiologic and Morphologic Assessment
Following Subarachnoid Hemorrhage
Vincent DiNapoli and Mario Zuccarello
Abstract
Subarachnoid hemorrhage (SAH) is a devastating cerebrovascular disease, comprising 5% of all strokes and
affecting 27,000 people in the USA annually. The acute changes in vascular physiology and morphology
immediately following SAH are poorly understood, and likely contribute to early fatality. Recent investiga-
tions have focused attention on early brain injury resulting from acutely decreased cerebral blood fl ow and
perfusion pressure mediated by increased intracranial pressure and vasoconstriction. Subsequent destruc-
tion of the microvascular architecture augments global ischemia and initiates a cascade of cellular injury.
This chapter presents a review of recent literature addressing the acute changes observed following
SAH. We have also provided a brief overview of basic methodologies utilized in these investigations.
Key words: Subarachnoid hemorrhage, Morphologic assessments, Early brain injury
1. Introduction
Subarachnoid hemorrhage (SAH) is a devastating cerebrovascular
disease, comprising 5% of all strokes and affecting 27,000 people
in the USA annually. Approximately half of all attacks are fatal,
many within the fi rst 48 h, and 30% of survivors will suffer signifi -
cant disability ( 1 ). SAH is classically the result of a ruptured cere-
bral aneurysm (Fig. 1 ). Pathologic aneurysmal dilation occurs
commonly at arterial branch points, and is known to have a genetic
predisposition. Cytokine activation of infl ammatory cells is
thought to mediate mechanisms driving this process via abnormal
vascular remodeling, resulting in expansion and rupture of the
vessel wall ( 2 ).
Mechanisms underlying immediate morphologic changes
within brain parenchyma following SAH are poorly understood.