= SUBACUTE NECROTIZING ENCEPHALOMYELOPATHY

= autosomal recessive disorder characterized by deficiencies in pyruvate carboxylase + pyruvate dehydrogenase complex + cytochrome c oxidase → anaerobic ATP production

• central hypotonia, ataxia, developmental regression / arrest
• ophthalmoplegia
• lactic acidosis = ↑ ratio of lactate to pyruvate in CSF + serum

Location: putamen (consistently), periaqueductal region, cerebral peduncles

• T2 prolongation of affected areas
• abnormally high lactate levels on MR spectroscopy