Ten Things That I Learned Today

1. Some things about aneurysms
- Acom aneurysms may be related to a hypoplastic A1-- the increased flow from the contralateral side may put shear stress on the vessel wall.
- Dolechoectatic aneurysms typically occur where there is low shear stress-- may be due to proteases?
2. Posterior communicating artery
- Drawing by me, out of a figure from 7 Aneurysms.

3. The anterior thalamoperforating vessels are the largest perforators off of the P-comm.

4. Posterior thalamoperforating arteries
- Come off of P2. Some argue P2 is the most important branch of PCA for this reason.
- Here's a picture I drew that's a replica of a figure in 7 aneurysms-- Thanks Dr.Lawton!

5. Cavernous sinus
- Vascular and nervous anatomy (another drawing of mine from 7 aneurysms)
- CN VI palsy most common with cavernous carotid aneurysm as the sixth nerve is the closest to ICA.

6. PCA

- On the (radiology right/normal person left) side of the image shows a p-com infundibulum at the origin of the pcomm off the ICA (the tiny text states that these never bleed ad do not need treatment unless they enlarge). On the same side, it also shows a normal pcom-PCA junction

- On the radiology left/normal R side of the image it shows a fetal PCA. Embryologically, the entire PCA territory is supplied by the ICA, and over time, P1 enlarges and the pcomm shrinks; but in up to 20% of the population, this doesn't occur completely, and the pcomm ends up supplying the PCA territory. This is relevant for if someone has a P-comm aneurysm and you're thinking about sacrificing the vessel.