brain stem features

Last reviewed 01/2018

Features directly attributable to brainstem demyelination in MS include:

  • paroxysmal features - transient dysarthria or cerebellar ataxia, usually of 20-30 minutes duration. Results from ephectic conduction between adjacent demyelinated axons.
  • vertigo due to impairment of balance
  • diplopia:
    • from demyelination of III, IV and VI nerves before leaving the brain stem; may be associated with trigeminal neuralgia with ipsilateral numbness and facial weakness due to proximity of III, IV and VI, to V and VII cranial nerves
    • or due to demyelination of the median longitudinal bundle - internuclear ophthalmoplegia
  • in more advanced disease, there may be pseudobulbar palsy, spastic dysarthria and emotional lability due to bilateral demyelination of pyramidal neurons