NBME 23 Impotence (NBME Answers)

NBME 23 Answers ↦

nbme23/Block 1/Question#11 (41.9 difficulty score)
A 55-year-old man who has a 10-year history ...
Impotence🔍,📺
tags: anatomy neuro

Tutor box

Members from the Leaderboard offering 1-on-1 help:

drdoom / drdoom.tutoring@gmail.com 📩
step-prep / step-prep contact form 📩

Want to be listed here? Email us!

+23
submitted by hayayah(1100),

unscramble the site ⋅ remove ads ⋅ become a member ($39/month)

eH hsa alecf eneninoincct so ish elrtnxea pterincsh si agdmd,ea ihhcw is danvtereni yb het plaenddu n. ().2SS-4 hTe clviep lhpiacsnnc erev,sn hiwhc imedeta hte nceietor orses,cp aer slao SS24.-

thomasburton Why could this not be dysuria? +3

lilyo I think that you are thinking about urinary incontinence. If we damage the pudendal nerve S2-S4, you can exhibit urinary and fecal incontinence since this nerve innervates both the urethral and the external anal sphincters. However since the pelvic splanchnic nerves also have roots that originate in S2-S4 a patient with pudendal nerve damage will also have impotence since these control the erection reflex. He wouldn't have dysuria which is painful urination. Most likely caused by a urethral infection or a blockade of the urinary tract. He would have urinary incontinence. I hope this helps. +16

alexxxx30 dysuria is painful urination...if it said urinary incontinence then you'd be right. But decreased innervation wouldn't cause pain (that would mores be associated with UTI) +3

peqmd Another approach is fecal incontinence => parasympathetic nerve dysfunction => no boner +2

dul071 ahhhhh fucked up with terminology again thinking dysuria was urinary incontinence +

+13
submitted by paperbackwriter(123),

unscramble the site ⋅ remove ads ⋅ become a member ($39/month)

,,2S43 eskep het 3 'Ps fof eth lorfo sn(i,eP ooP, dna Pe)e

alexxxx30 love it +1

prolific_pygophilic A true scholar +3

+5
submitted by medstudent22(9),

I took the approach of 10 year history DM --> Chronic DM complications = 1. Nonenzymatic Glycosylation (NEG) 2. Osmotic Damage.

Osmotic Damage can lead to neuropathy and autonomic degeneration. Fecal incontinence can be indicative of autonomic damage (parasympathetics = rest + digest = poop; There was a UWorld Q about constipation + parasympathetics - can't remember ID Sorry).

A. Dysuria --> Not related to NEG or osmotic damage

C. Inability to climb stairs --> Motor > sensory, so unlikely NEG or osmotic

D. Night-time leg cramps --> Claudication/PAD can present with symptoms that are worse at night when legs are horizontal with height, however this isn't cramping pain, which hints to an MSK problem or RLS.

E - Sciatica --> Not related to NEG or Osmotic Damage.

That leaves us with B --> Erections are obtained by pointing, shooting, and squeezing (parasympathetics, sympathetics, somatic). Impotence specifically is failure to obtain erection = failure to point = failure of parasympathetics = autonomic instability secondary to osmotic damage

Reference = FA2018 - page 344

drdoom damn this write-up beautiful +