Diagnostic clues in an adult case of Leigh's disease.

A previously-well 32-year-old woman presented with episodes of severe headache, neck pain, numbness of the tongue and facial sweating. In the course of her illness she became abulic, blind and quadriparetic and she suffered recurrent episodes of coma during which she became decerebrate and her brain-stem reflexes were absent. She had an adult form of Leigh's disease, which is an extremely-rare degenerative condition of unknown cause. The clinical, neuroradiological and neuropathological features are presented.