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Diagnosis and Evaluation of Aneurysmal Subarachnoid Hemorrhage

Last Updated: September 28, 2018

Subarachnoid hemorrhage (SAH) is defined as bleeding around the brain confined within the subarachnoid space between the arachnoid membrane and the pia mater. The etiology of SAH can be divided into two main categories: 1) spontaneous, and 2) traumatic. I will discuss only spontaneous SAH in this chapter.

The incidence of aneurysmal SAH reaches an annual rate of 6 to 8 per 100,000. Its sequelae can lead to death and significant functional disability, with mortality rates reaching 45%. A number of causes are associated with development of spontaneous SAH.

Table 1: Etiologies of Spontaneous Subarachnoid Hemorrhage
Ruptured intracranial aneurysm (75-89%)
Cerebral arteriovenous malformation
Dural and pial arteriovenous fistula
Dural venous sinus thrombosis
Pretruncal/perimesencephalic nonaneurysmal SAH
Cerebral artery dissection (internal carotid and vertebral arteries)
Rupture of an infundibulum