NBME 16 Answers ↦
I was able to deduce the right answer, but what is the specific reason against "demyelination of the corticospinal pathways"? just out of curiousity
I believe it's because damage to the corticospinal tract would be considered UMN damage, while degeneration of motorneurons is LMN damage. LMN damage causes decreased reflexes. UMN disease would cause hyperreflexia....I think. That's how I reasoned through it at least
I also think you can rule out peripheral neuropathy because typically that includes both motor and sensory
yes but is not Achilles an S1 reflex (sacral cord) ? how does the degeneration in lumbar cord affects it ? i rule it out first thing because of this :S
i think she just had a dics herniation. there can be problem with temperature and sensation in some case but those are usually very severe herniations. not sure tho... but it can on your differentials.
I assumed that "motoneurons of the lumbar chord" means upper and not peripheral