Time again for #NeuromuscularQandA? RT. #neurology #medtwitter #MedEd #medstudent #neurologyresident Join me in discussing/learning/educating with #passion and #humor @WNGtweets @MonicaDhakar @MadSattinJ @NinaRiggins @AaronLBerkowitz @RachelSalasMD
Let’s have a philosophical discussion today. Q: Doc doc there are fibs and sharps everywhere on the EMG! Arms, legs, thoracic and lumbar paraspinals. NCS normal. What could it be?
A: Ah, widespread muscle membrane instability. Could be neurogenic, could be myopathic. What’s the recruitment like? Remember reduced recruitment in neurogenic and normal or rapid in myopathic.
Q: Mostly normal. Normal looking motor units too. Likely myopathic then? Shall we get CKs to see if it’s muscle?
A: CKs are gonna be moderately raised if there’s widespread denervation anyway. That’s why motor neuron diseases or polyradiculopathies can have a tad raised CK. You sure there isnt a fasciculation hiding anywhere?
Q: Just 1 or 2 muscles...why?
A: Fasciculations come from motor neurons not muscle. There’s a chance it could still be neurogenic. Could be polyradiculopathy - degenerative, infectious, inflammatory, neoplastic. Get MRI contrast and CSF studies. Remember ALS is a clinical diagnosis of exclusion.
Q: Dat normal doc. What else?
A: Muscle biopsy can distinguish between neurogenic atrophy (fiber type grouping and atrophy) and myopathy (variability in fiber size, split fibers, increased internal nuclei, myophagocytosis, necrotic fibers).
Bonus: Okrums razor or Hickams dictum?
@threadreaderapp pls unroll
