Pretty involved question for ya...

[acpce1]

---

Members do not see this ad.

I don't have the true Q-Bank, but I bought some CD off a guy off of eBay that has supposed Q-Bank questions. So stop me if you've heard this one:

A neurological examination of a 47-year-old woman reveals a normal
corneal reflex in her right eye, but no consensual corneal reflex in
her left eye. Which of the following additional findings might be expected?
A. Absence of pupillary light reflex of the left eye
B. Hyperacusis of the left ear
C. Inability to abduct the right eye
D. Loss of pain and temperature of the left face
E. Loss of taste from the anterior two-thirds of the rightongue
F. Ptosis of the left eye

Answer and reasoning to come later...

 

[tega]

the obvious answer is probably "b'....stapedius innervated by facial on the left.....same nerve modulating motor efferent corneal on the left. But this may be trickier. But if facial is the answer case , why aren?t there other facial motor lesions


chocie "e" , ptosis, seems like a sexy answer also....but occulomotor causes marked ptosis.....and choice "a" refers to the same nerve (both probably wrong then). and nothing in the question indicates an occulomotor lesion.


so i go with facial......


**** i need to learn the "facial nerve" matrix in z skull....only if i knew exactly where c.tympani comes off..this q would have been cake... 😀

 

[BrooklynDO]

ran into this , i think its in qbook dude. you have to know that whats affected is CN7 (on the left) and that taste is mediated ipsilaterally (assuming you already knew that cn7 also mediates taste)
so you ruled out all the pain stuff since thats cn5, rule out E for taste...correct shoulda been loss of right sided taste sensation, and then you have B, which is all thats left. I couldnt remember why hyperaccusis would be involved but then you dig into the depths of first year anatomy and reaslize something about the stapedius i think being innervated by CN7.... also its the only choice that wasnt wrong for a specific reason I could think of 😛

 

[csmith1]

i have no problem with facial. would choice 'd' be as easy to eliminate if it read 'loss of sensation on left forehead and eyelid'?

i'm thinking about the afferent limb here, V1, and trying to understand what symptoms would rule it in, rather than out.

spanx in advance.

(i'm also secretly hope marchiafava calls me stupid.... )

 

[BrooklynDO]

the problem is not the afferent, its the effferent..loss of the concensual part...meaning the other eye doesnt blink, which is all CN7... and your version of choice D would still be eliminated because its CN5, which is the afferent, not the efferent limb... oh, and JU STUPID.... i know i cant do it quite as well as marchiafava, but im hopin you feel better now? 😛

 

[csmith1]

OIC

Reading the scenario again and what you said, I see it now....I had read it initially to read that the right cornea was stroked and a response was obtained, THEN they stroked the left cornea and got nuttin'. Now that could point to left V1, correct?

in case you haven't noticed, i have a grudge against the trigeminal.

 

[coconut lime]

how do you know whether it's the afferent or efferent limb that's not working?

 

[BrooklynDO]

because the question can be translated as : when i prick your rigth eye, it blinks (afferent and efferent works on the right) but at the same time, your left eye which should blink, doesnt (we know the afferent is working from the right eye... so that must mean that the reason the left eye doesnt blink is because the efferent limb has a problem)

 

[imtiaz]

yeah the answer is B, chalk another one up for B!

 

[coconut lime]

so how about if you touch the left eye. will only the right eye blink?

 

[BrooklynDO]

yup............................