Juvenile-onset Leigh syndrome with an acute polyneuropathy at presentation

Subacute necrotizing encephalomyelopathy or Leigh syndrome can be associated with a polyneuropathy. By far, the most commonly encountered neuropathy is a chronic neuropathy with features of demyelination, which can be the presenting manifestation of Leigh syndrome. On rare occasions, the neuropathy encountered can represent a more acute process. We describe a rare case of juvenile-onset Leigh syndrome presenting with an acute polyneuropathy.