Step I HY Neuroanatomy questionable case study?

[neopentanol]

So theres a case study on page 48 that has me twisted.

Its a guy with complete hemianopia and contralateral face and limb sensory loss, and the diagnosis is posterior cerebral artery infarct.

What threw me off is the lack of macular sparing in the scenario, and where the contra face/limb sensory loss comes from in PCA infarct. Is it thalamic syndrome? somatosensory cortex (ACA)? Any input would be appreciated thanks guys!

 

[mrmandrake]

An infarct to the posterior limb of the internal capsule may cause these symptoms. That's my best guess.

The posterior limb of the capsule contains the sensory fibers (pain & temp) and the visual radiations, which might explain why there isn't macular sparing because the infarct isn't in the cortex.

I believe a branch of the MCA perfuses the posterior limb though, so not sure about that one.

 

[username456789]

An infarct to the posterior limb of the internal capsule may cause these symptoms. That's my best guess.

The posterior limb of the capsule contains the sensory fibers (pain & temp) and the visual radiations, which might explain why there isn't macular sparing because the infarct isn't in the cortex.

I believe a branch of the MCA perfuses the posterior limb though, so not sure about that one.

Yeah I don't think the PCA serves the internal capsule, but it might be a thalamic thing like the OP said.

Regarding the macular sparing, in a perfect world/on a perfect question it'd be mentioned, but in reality it'd probably take a pretty detailed eye exam to flesh that part out. The history they gave seems pretty typical of what you might get from a patient when they show up at your office.

 

[jerryjr36]

are we talking about Weber syndrome?

 

[username456789]

are we talking about Weber syndrome?

Doesn't sound like it. No extraocular muscle paralysis, no upper motor neuron symptoms, etc.