Peripheral neuropathy in Leigh's encephalomyelopathy.

An infant with subacute necrotising encephalopathy is described, in whom slow motornerve conduction velocities suggested the presence of peripheral neuropathy. Peripheral nerves are not invariably involved in patients with this disease, but as they are involved in thiamine-deficiency states it is conjectured that the presence or absence of peripheral neuropathy in patients with subacute necrotising encephalopathy may distinguish those with thiamine triphosphate deficiency from those in whom the disease is due to other causes.