Chapter 429: Subarachnoid hemorrhage

Question 1

Most common cause of SAH

Answer 1

Rupture of a saccular aneurysm

Question 2

Overall mortality rate for aneurysmal SAH

Answer 2

35%

Question 3

Annual risk of rupture

Answer 3

If <10 mm: ~0.1%

If >10 mm: ~0.5-1%

Question 4

3 most common location of Giant Aneurysms (>2.5 cm)

Answer 4

1. Terminal internal carotid artery
2. Middle cerebral artery bifurcation
3. Top of the basilar artery

Question 5

Mycotic aneurysm usually located

Answer 5

Distal to the first bifurcation of major arteries of the circle of willies

Question 6

85% of aneurysms occur in the __

Answer 6

Anterior circulation

Question 7

Predictors of greater risk of rupture

Answer 7

1. > 7 mm in diameter
2. Top of the basilar artery
3. Origin of the posterior communicating artery

Question 8

Hallmark of aneurysmal rupture

Answer 8

Sudden headache in the absence of focal neurologic symptoms

Question 9

Prodomal syndrome: Location of rupture

Third cranial nerve palsy
Pupillary dilatation
Loss of ipsilateral light reflex
Focal pain above or behind the eye

Answer 9

Expanding aneurysm at the junction of the posterior communicating artery and the internal carotid artery

Question 10

Prodomal syndrome: Location of rupture

6th nerve palsy

Answer 10

Aneurysm in the cavernous sinus

Question 11

Prodomal syndrome: Location of rupture

Visual field defects

Answer 11

Expanding supraclinoid carotid or ACA aneurysm

Question 12

Prodomal syndrome: Location of rupture

Occipital and posterior cervical pain

Answer 12

Posterior inferior cerebellar artery or anterior cerebellar artery aneurysm

Question 13

Prodomal syndrome: Location of rupture

Pain in or behind the eye and in the low temple

Answer 13

Expanding MCA aneurysm

Question 14

4 major causes of delayed neurologic deficits

Answer 14

1. Rerupture
2. Hydrocephalus
3. Delayed cerebral ischemia
4. Hyponatremia

Question 15

Incidence of re-rupture of an untreated aneurysm in the first month following SAH is ______, with the peak in the ______

Answer 15

~30%, first 7 days

Question 16

Acute stupor and coma

Answer 16

Acute Hydrocephalus

Question 17

Progressive drowsiness or slowed mentation with incontinence

Progress over days to weeks

Answer 17

Subacute hydrocephalus

Question 18

Develop weeks to months 
Gait difficulty
Incontinence 
Impaired mentation 
Lack of initiative in conversation 
Failure to recover indepence

Answer 18

Chronic hydrocephalus