SAH Flashcards
WFNS has how many grades?
5
What are the components needed to grade with WFNS?
GCS (main component!) and presence of major focal deficit
What are the grades of WFNS?
1: GCS 15, normal exam
2: GCS 13-14, normal exam
3. GCS 13-14, major focal deficit***
4. GCS 7-12, any exam finding
5. GCS 3-6, any exam finding
What is the dose of nimotop used?
What if BP is too labile?
60mg PO Q4hr
Can use 30mg PO Q2hr
Significance of hyponatremia in aneurysmal SAH patients?
Hyponatremia has been chronologically associated with the onset of sonographic and clinical vasospasm
What is the typical time course for cerebral vasospasm after SAH
Almost never before day 3 Peak on days 6-8 Rarely after day 17 Main period of risk: days 3-14 Almost always resolved by day 12 Once it is seen radiographically, it usually resolves over 3-4 weeks
What is the correlation between hunt & Hess score and clinical vasospasm?
Grade 1: 22% Grade 2: 33% Grade 3: 52% Grade 4: 53% Grade 5: 74%
What score is used to describe the risk of vasospasm with the amount of SAH blood seen on head CT?
Modified Fischer scale
What are the modified Fischer scale groups?
1: focal or diffuse thin SAH, - IVH
2: focal or diffuse thin SAH, +IVH
3. Focal or diffuse thick SAH, -IVH
4. Focal or diffuse thick SAH, +IVH
What are the predicted risks of vasospasm with the modified Fischer scale?
Scale 1: 24%
Scale 2: 33%
Scale 3: 33%
Scale 4: 40%
What drug is used with intra-arterial endovascular vasospasm treatment?
Verapamil
Which side do you approach a basilar summit aneurysm?
Right crani unless existing left CN III palsy, existing right hemiplegia, or other left sided aneurysms to clip
What craniotomy is done to expose the basilar summit- what are the steps?
Orbitozygomatic- pterional plus 6 cuts w a reciprocating saw:
- Notched cuts at the root of the zygoma (angled anteriorly to avoid the TMJ joint posteriorly).
- Cut across the malar eminence (temporal process) of the zygomatic bone beginning at the inferolateral margin of the zygomatic arch and continuing half way into the temporal bone
- Cut from the inferior orbital fissure through the zygoma out to meet the last cut
- A cut in the medial orbital rim lateral to the supraobital notch extending across the orbital roof posteriorly
- Continues the orbital roof cut laterally out into the sphenoid wing and pterion
- A cut from the inferior orbital fissure up to the prior sphenoid/pterion cut.
Additional drilling is done to take down the sphenoid wing, lateral orbital roof and wall
5.
What are the contents of the inferior orbital fissure?
- Infraorbital nerve (branch of V3): sensation to the lower lid, upper cheek, side of the nose, upper lip
- Zygomatic nerve (branch of V3): sensation to the zygoma and temporal region
How do you mobilize the temporal lobe?
Widely split the Sylvian fissure, retract the temporal lobe posterolaterally which requires liberating arachnoid adhesions on the inferior temporal lobe and untethering the anterior temporal pole by sacrificing the vein to the sphenoparietal sinus, and by dissecting the anterior choroidal artery: courses around the medial uncus, follows the optic tract to the lateral aspect of the cerebral peduncle and enters the crural cistern.
