Q: Is it an aneurysm or a malformation?
A: Malformation
favorite ABR topic/question
many cases on HSS
There are three types
Choroidal (fistula)
type present as neonates with high flow CHF
Mural (fistula)
the dilated VOG typically drains to a falcine sinus (median vein of the prosencephalon a la Lasjaunias)
(mural and choroidal types may be difficult to distinguish, unsporting to ask a resident to do this)
AVM (typically thalamic)
drains to VOG typically to a straight sinus
Q: Why do these patients get hydrocephalus
a. pressure on the cerebral aqueduct
b. venous hypertension (decreased CSF resorption)
A: b. venous hypertension (decreased CSF resorption)
topic comes up frequently at the Berenstein neurointerventional conference
Reference
http://www.medscape.com/viewarticle/545335_5
Dr. Berenstein (at RH collaborated with Dr. Lasjaunias, residents interested in neurointerventional should be aware or their 5 volume work Surgical Neuroangiography (see Dr. Lasjaunias’ eulogy in the lancet )(http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(08)61577-9/fulltext)