[ Neurosurgery ] SAH 1

SAH – effects

Chemical meningitis, raised ICP, and possible global cerebral ischemia.

Aneurysmal SAH – epidemiology

Females more than males (3:2), age 40 to 60, peak 55 to 65 (post-menopausal risk).

SAH survivors – outcome

One third die within 1 month, one third have severe deficits, one third have good results.

Traumatic SAH – significance

Most common cause of SAH overall (80%).

Spontaneous SAH – frequency

20% of SAH.

Ruptured berry aneurysm – significance

Most common cause of spontaneous SAH (80%), about 30% rupture during sleep.

Berry aneurysm – other name

Saccular aneurysm.

Spontaneous SAH – other causes (examples)

Mycotic aneurysms, vasculitis, and tumors.

Berry aneurysm – definition

Thin-walled dilation at arterial bifurcations (circle of Willis).

Berry aneurysm – epidemiology

Females more than males (3:2), peak age 55 to 65, ruptured to unruptured ratio 5:3.

Berry aneurysm – warning symptoms

50% have warning symptoms 1 to 3 weeks before SAH.

Berry aneurysm – most important etiology

Congenital weakness or absence of the tunica media at arterial bifurcations.

Berry aneurysm – hemodynamic stressors

Hypertension (major acquired risk factor) and atherosclerosis.

Traumatic intracranial aneurysm – type

Dissecting aneurysm.

Familial cerebral aneurysms – key association

ADPCKD.

Cerebral aneurysm – risk factors (examples)

HTN, smoking, alcohol, caffeine, and OCP.

Cerebral aneurysms – location distribution

85 to 95% in the ICA (anterior) circulation.

SAH – associated hemorrhages

ICH in 20 to 40% and IVH in 15 to 35%.

Anterior circulation aneurysms – frequency and commonest site

Most common (90%), with ACOM the most common site overall.

ACOM aneurysm – compression effect

Compresses the optic chiasm and pituitary, causing bitemporal hemianopia