1. Vein of galen malformation
- Not really vein of galen, actually median prosencephalic vein of markowski, which is an embryonic precursor of the vein of galen that doesn't regress to be replaced as it should
- Occurs in 16th to 18th week of embryogenesis-- sinuses that later regress are visible (Falcine sinus? although this can also be patent in patients with thrombosed straight sinuses)
- Presents with high-output heart failure; can even present as antenatal heart failure
- If cases of massive shunt, the first task should be to evaluate the extent of brain damage to evaluate likelihood of meaningful recovery to guide care options, especially in light of the fact that these kids also suffer from liver failure and renal failure (presumably from lack of perfusion) and consumptive coagulopathy
- Can get parinaud's because the malformation is sitting on tectum
- They are hard sticks because their peripheral vessels are all collapsed (all blood shunted)
2. Types of malformations (Lasjaunia's classification) 
- Choroidal type: presents earlier in infancy, more severe shunt; multiple feeder vessels (choroidal, thalamoperforating, callosal)
- Mural type: presents later in childhood, less severe shunt, single fistula between median prosencephalic vein of markowski and feeder vessels.
3. Vein of galen malformations and hydrocephalus: 
- causes hydrocephalus from increased pressure in sinuses, lack of forward drainage.
- placing VP shunt can cause upward herniation
- placing VP shunts are also a high risk for bleeding because of the altered venous drainage pattern in the brain- blood is shunted to medullary veins, exactly where the catheter goes.
4. Aneurysms
- Form where there is shear stress -- in the direction of the net vector of flow. i.e., when at a bifurcation, it forms distal to the branch.
- Plaques form where there is low shear stress.
5. Ascending pharyngeal artery (APA) has anastomoses to many intracranial vessels
- Anastomosis to ICA via meningiohypophyseal trunk-- ACA sends branches up clivus, MHT sends branches down clivus
- The neuromeningeal trunk supplies the cranial nerves; as one would logically expect, the branch that goes through the jugular foramen (jugular division) supplies IX, X, and XI, while the one that goes through the hypoglossal canal (hypoglossal division) supplies XII.
- IF YOU EMBOLIZE EITHER OF THE ABOVE BRANCHES YOU WILL CAUSE CN IX, X, XI, or XII PALSIES. 
- Often, posterior fossa dural fistulas or dural-vascular lesions or mengiomas will have blood supply from the APA so it's useful to angio

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"Intracranial Branches of the AP: {source}

A: Neuromeningeal Trunk

B: Hypoglossal Division of the Neuromeningeal Trunk (medial to Jugular divion on the AP view), which typically supplies: 

      C: Ascending clival branches which anastomose with each other and with inferior clival branch of MHT (L)

      D: Descending branch exiting thru foramen magnum and anastomosing at C3 with vertebral branches (odontoid arcade)

 E: Jugular Division of the Neuromeningeal Trunk, which typically supplies:

           F: Anterior branches anastomosing with lateral clival branches of the inferolateral trunk (ILT) near Dorello’s canal

           G: Sigmoid Sinus branch along Sigmoid Sinus wall, anastomosing with petrosquamosal branches of the MMA (J), Lateral Tentorial Artery of the MHT, and Occipital Artery transosseous branches (N)

 H: Inferior tympanic branch, supplying middle ear and anastomosing with carotidotympanic branch (N) of the ICA  (see aberrant carotid artery below)

 I: Foramen Lacerum branch of the pharyngeal division of AP, anastomosing with recurrent lacerum branch of the ILT (M)" 

6. Nervous tissue testing before embolization or other procedures: 

- Brain: amytal

- Peripheral: lidocaine

- Spine: both, but with a saline flush in between; amital is an acid and lido is a base, if they are in the blood together at the same time they will crystallize. 

- Eye: amytal 

7. Embolization of meningomas

- Some people wait a week after embolization to operate, with the logic being that you increase necrosis and thus make it easier to suck out

- Some people will go right after embolization, with the logic that you avoid postprocedural swelling 

8. Cartoid dissections

- Classically, a low, smoothly stenotic segment in a young person. 

- Stops at the skull base, because the way the layers of the vessel is tacked to the dura. 

- If someone has acute neck pain during angio, suspect iatrogenic dissection; you'll want to immediately give heparin and then aspirin if you caught it early; if you catch it late, aspirin only. Most will heal. Some will embolize and stroke. 

9. Intracranial dissections

- Vessels in the brain have a thinner adventitia than vessels outside; dissections often go through all 3 layers

- Higher bleed rate than aneurysms 

- Intracranial vert dissection - most common intracranial dissection, can sacrifice if non-dominant 

- Supraclinoid dissection ( = blister aneurysm) - second most common.  Impossible to clip. Difficult to coil. Can attempt coil + pipeline or coil + bracing stent. Generally speaking, carotid blister aneurysms are associated with horrible outcomes, especially if you have to sacrifice the carotid. The goal in management is to prevent carotid sac at all costs. 

10. Traumatic carotid cavernous fistula

- If someone has vision loss, if it's immediate - it was due to the trauma and will not recover, if the onset is gradual, it's due to the fistula and will improve when  you fix the fistula. 

- Delayed hemorrhage after trauma: c-c fistula with dissection 

- Delayed epidural hemorrhage after trauma: skull base fracture with middle meningeal artery fistula formation