1/
Me: Lift up your leg.
Patient: I can't!
Me: Ok, look at it and then lift it.
Patient: (lifts leg) Woah!
Me: Voila!
A #tweetorial #neurotwitter #MedTwitter #neuromuscular #MedEd #neurology
Hint: It's not functional neurologic disorder (FND)
Another Hint:

2/
35-year-old female with chronic Etoh use disorder presents after progressive ambulatory decline for 6 months. She's in a wheelchair. She feels numb all over and feels too weak to walk. She has no pain. So far everyone's "blamed it on the a-a-a-a-alcohol"
Lets go to the "Buckets"
🪣 Motor Neuron ❌
🪣 Root
🪣 Plexus
🪣 Nerve
🪣 Neuromuscular Junction ❌
🪣Muscle❌

3/
Exam:
-Normal cognition, strong facial muscles and tongue, normal eye movements, and good neck strength.
-Appears thin with some atrophy of quadriceps but no fasciculations.
-Limb strength 3/5 in all muscle groups
-Reflexes absent
-Dullness to pinprick and loss of vibration throughout limbs in non-length dependent fashion
-Impaired toe proprioception
-Gait-very ataxic, could hold herself up but had to hang on to me, we had to sit down quickly
Lets go back to the "Buckets"
🪣 Motor Neuron ❌
🪣 Root
🪣 Plexus ❌
🪣 Nerve
🪣 Neuromuscular Junction ❌
🪣Muscle❌

4/
So far it looks like a sensory AND motor process, so it's easy to knock out motor neuron, NMJ and muscle.
Also, findings are too widespread to be a plexopathy.
That leaves roots and nerves. Six-month onset makes me think CIDP, but it's weird that she has no pain, burning, or tingling feelings. She's just...numb.
Alcohol use makes me wonder about alcohol related neuropathy, but isn't this too fast, too severe? Hmm what next?
EMG! (Yes, imaging of the neuroaxis was normal🙃)

5/
OH SNAP! 🫰🫰🫰🫰🫰
The SNAPs (sensory nerve action potentials) were absent in the arms and legs, while CMAPs (compound muscle action potentials) were perfect. No conduction block or temporal dispersion (we will get to this on a future tweetorial :))
Needle EMG was normal.
I looked at her again and re-checked her strength and when she looks at the limb with intention, turns out she's 5/5, but very ataxic with her eyes closed.
Like #theroots, this case has got a funky beat 🎷🎹

6/Lets go back to the "Buckets"
🪣 Motor Neuron ❌
🪣 Root
🪣 Plexus ❌
🪣 Nerve ❌
🪣 Neuromuscular Junction ❌
🪣Muscle❌
Looks like it's pure sensory, and she has perceived weakness due to profoundly impaired proprioception.
It would be hard to imagine a pure sensory, non-length dependent neuropathy without any motor involvement, so I took out the nerve 🪣

7/
She has sensory ganglionopathy... I call it the notorious DRG.
It is most often immune mediated and very specifically affects the cell bodies within the dorsal root ganglia (DRG)
Causes include:
Paraneoplastic
Autoimmune-Sjogren's, SLE
Infection-HIV, HTLV-1, EBV, others
Drug/Toxicity-Platinum based chemo, B6, Checkpoint inhibitors
Idiopathic

8/
It's a good idea to put this case in your Roots 🪣 and never miss the chance to potentially treat and help your patient walk again!
Immunotherapy can halt disease progression, but it's not always successful. The best response is with early treatment.
Take home point: Use the buckets to help you localize and make sure you have a good hypothesis for why someone can't walk before you blame alcohol or FND!

9/
Thanks for reading! I hope this helps you localize. And if you don't know #theroots check them out, great late 90's vibe...