Pyruvate decarboxylase deficiency in subacute necrotizing encephalomyelopathy.

A partial deficiency of pyruvate decarboxylase (PDC) was demonstrated in a child with hyperlactatemia and progressive ataxia, bulbar paresis, ophthalmoplegia, and polyneuropathy. Subacute necrotizing encephalomyelopathy (SNE) was found at necropsy. The association of SNE and PDC deficiency has been reported rarely, but a review of the diverse metabolic defects associated with SNE suggests that decreased PDC activity may be the common feature of SNE.