Leigh disease /lē/ [Archibald Denis Leigh, British neuropathologist, b. 1915] , an encephalopathy of unclear clinical and pathological criteria, causing neuropathological damage like that of the Wernicke-Korsakoff syndrome. It occurs in two forms: the infantile form, which may be the same as pyruvate carboxylase deficiency, is characterized by degeneration of gray matter with necrosis and capillary proliferation in the brainstem; hypotonia, seizures, and dementia; anorexia and vomiting; slow or arrested development; and ocular and respiratory disorders. Death usually occurs before age 3. The adult form usually first manifests as bilateral optic atrophy with central scotoma and color blindness; then there is a quiescent period of up to 30 years before late symptoms appear, such as ataxia, spastic paresis, clonic jerks, grand mal seizures, psychic lability, and mild dementia. Also called subacute necrotizing encephalomyelopathy, subacute necrotizing encephalopathy. See also Wernicke-Korsakoff syndrome.
