Intracranial Subarachnoid Hemorrhage

Abstract

Subarachnoid hemorrhage (SAH) represents one of the most neurologically devastating forms of cerebrovascular accident. Fewer than 60% of patients suffering from the malady will recover cognitively and functionally to their premorbid state. From 65% to 70% of all SAH results from rupture of intracranial berry aneurysms. Arteriovenous malformations, neoplasm, and angiomas are responsible for most of the remainder. Systemic diseases associated with an increased incidence of berry aneurysm include Marfan’s syndrome, Ehlers-Danlos syndrome, sickle cell disease, coarctation of the aorta, alpha 1-antitrypsin deficiency, polycystic kidney disease, fibromuscular vascular dysplasia, and pseudoxanthoma elasticum. Hypertension, alcohol and caffeine consumption, smoking, and cocaine use, which are modifiable risk factors, and cerebral atherosclerosis increase the risk of SAH. Blacks are more than twice as likely to suffer SAH when compared with whites. Female patients are affected more often than male patients, and the mean age of patients suffering from SAH is 50 years.

Keywords

subarachnoid hemorrhage, berry aneurysms, Marfan’s syndrome, sickle cell disease, coarctation of the aorta, Ehlers-Danlos syndrome, hypertension

ICD-10 CODE 160.9

The Clinical Syndrome

Subarachnoid hemorrhage (SAH) represents one of the most neurologically devastating forms of cerebrovascular accident. Fewer than 60% of patients suffering from the malady will recover cognitively and functionally to their premorbid state. From 65% to 70% of all SAH results from rupture of intracranial berry aneurysms. Arteriovenous malformations, neoplasm, and angiomas are responsible for most of the remainder ( Fig. 9.1 ). Berry aneurysms are prone to rupture because of their lack of a fully developed muscular media and collagen-elastic layer. Systemic diseases associated with an increased incidence of berry aneurysm include Marfan’s syndrome, Ehlers-Danlos syndrome, sickle cell disease, coarctation of the aorta, alpha 1-antitrypsin deficiency, polycystic kidney disease, fibromuscular vascular dysplasia, and pseudoxanthoma elasticum ( Box 9.1 ). Hypertension, alcohol and caffeine consumption, smoking, and cocaine use, which are modifiable risk factors, and cerebral atherosclerosis increase the risk of SAH. Blacks are more than twice as likely to suffer SAH when compared with whites. Female patients are affected more often than male patients, and the mean age of patients suffering from SAH is 50 years. Even with modern treatment, the mortality associated with significant SAH is approximately 25%.

Box 9.1

Systemic Diseases Associated With an Increased Incidence of Berry Aneurysm

Marfan’s syndrome
Ehlers-Danlos syndrome
Sickle cell disease
Polycystic kidneys
Coarctation of the aorta
Fibromuscular vascular dysplasia
Pseudoxanthoma elasticum

Signs and Symptoms

Massive SAH is often preceded by a warning in the form of what is known as a sentinel or thunderclap headache. This headache is thought to be the result of leakage from an aneurysm that is preparing to rupture. The sentinel headache is of sudden onset, with a temporal profile characterized by a rapid onset to peak in intensity. The sentinel headache may be associated with photophobia and nausea and vomiting. Of patients, 90% with intracranial SAH will experience a sentinel headache within 3 months of significant SAH.

Patients with significant SAH experience the sudden onset of severe headache, which the patient often describes as the worst headache of his or her life ( Fig. 9.2 ). This headache is usually associated with nausea and vomiting, photophobia, vertigo, lethargy, confusion, nuchal rigidity, and neck and back pain ( Box 9.2 ). The patient experiencing acute SAH appears acutely ill, and up to 50% will lose consciousness as the intracranial pressure rapidly rises in response to unabated hemorrhage. Cranial nerve palsy, especially of the abducens nerve, may also occur as a result of increased intracranial pressure. Focal neurologic signs, paresis, seizures, subretinal hemorrhages, and papilledema are often present on physical examination.