Wednesday, October 29, 2008

SAH Board pearls

1. 90-95 percent of berry aneurysms are on the anterior part of the circle of Willis.
2. In order of frequency, they occur at proximal ACOMA, origin of PCOM artery from the stem of the ica, the first major bifurcation of the MCA, and the bifurcation of the ICA into ACA and MCA. Other sites: cavernous sinus, origin of the opthalmic artery, junction of the post com and PCA, bifurcation of the BA, origin of the 3 cerebellar arteries.
3. Other aneurysm "types" defined are mycotic, or named morphologically, fusiform, diffuse and globular.
4. Seizures occur in 10-25 %
5. Nimodipine 60 q 4 hours does not alter occurrence of vasospasm but does reduce the risk of stroke with vasospasm.
6. Rate of rupture of incidentally discovered aneurysm relates to size, is .1 % yearly for less than 7 mm, .5 % for 7-10 mmm and .6-3.5 percent annually for 13-24 mm.
8. Occurrence of UIA in family members (first degree) is 3-4 % in them if one family member has, screening is not mandatory but some want it. If 2 family members have, 9 % of first degree relatives over 30 also have and screening with CTA/MRA is indicated.
9. Smoking, hypertension, and female gender are predictors of ICA in relatives
10. Others who need to be screened are those with ADPKD if others in family have a history of aneurysm, and those with coarctation of aorta (10% have aneurysm).
11. Warfarin can be used in those with aneurysm (Bob Brown) if otherwise indicated. For small aneurysms (< 10 mm) there is not evidence that risk of rupture is elevated. For larger aneurysms, risk is unknown.
12. Risk factors for SAH include hypertension, smoking, cocaine use, positive family history and excessive alcohol use. HTN also is a risk factor for bad outcome if not controlled. Risk of rupture increases with increased aneurysm size, prior SAH, and posterior circulation location.

1 comment:

Anonymous said...

add pearl-- consensus on treatment for mycotic aneurysm does not exist, but Ropper prefers to use medical therapy.