Monday, 13 September 2010

MRCP revision battle 10.5: Multifocal motor neuropathy

I must confess I'd never come accross multifocal motor neuropathy until I started doing MRCP questions, but I'm now rather glad that I have, as essentially it is a treatable differential diagnosis for some presentations that appear like MND (which, as we've just covered, is nasty and deadly)

Multifocal motor neuropathy is an acquired immune-mediated demyelinating neuropathy.

Features of multifocal motor neuropathy include:
  • slowly progressive, asymmetric distal muscle weakness
  • cramps and twitching
  • no sensory loss
  • no/minimal muscle atrophy
  • possibly positive anti GM1 antibodies (NB also + in GBS)
  • no UMN signs
  • normal or decrease tone
  • absent reflexes

The joy of multifocal motor neuropathy is that it can be successfully treated with IV IG!

Well thats quite enough neurology for today, lets now look briefly at Lesch-Nyhan Syndrome, as promised yesterday