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nbme24/Block 4/Question#17

A 63-year-old woman undergoes operative repair of a ...

Decreased movement through the arachnoid villi

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 +4  upvote downvote
submitted by colonelred_(45),

Normally the arachnoid villi drains the CSF from the subarachnoid space to the venous system; if this part becomes defective then you can imagine all that CSF now building up in the subarachnoid space.

keycompany  Also take into account this patient had surgery that requires penetration into the subarachnoid space (hence through the arachnoid mater). This can lead to scarring of the arachnoid granulations and subsequent communicating hydrocephalus. +5  




 +1  upvote downvote
submitted by roygbiv(5),

The patient has a leaking berry aneurysm --> this leads to a subarachnoid hemorrhage (or leakage into subarachnoid space) --> acute SAH can lead to decreased absorption and movement via arachnoid villi

zbird  So this patient has a leaking berry aneurysm which undergone to surgery and repaired but in two days she developed widening of the SA space which could be explained by increased CSF production but a decreased in absorption, which is due to blockage of the arachinoid granulations by the leaked red and white cells therefore there is a decreased movement of the CSF via the arachinoid villi +1  




 +1  upvote downvote
submitted by happysingh(2),

so, the Key words that no one is mentioning : communicating hydrocephalus

the pathophys goes like this :

an inflammatory setting (i.e., subarachnoid hemorrhage) yield fibrosis / scarring of the arachnoid granulations => impaired CSF drainage

the key points / concepts they are trying to test here : 1. do you know what communicating hydrocephalus (without them telling you those words) 2. do you know what's the pathophysiology (of communicating hydrocephalus) is ?