Neuropathological Observations in Maple Syrup Urine Disease

Abstract
Maple syrup urine disease is one of the newly recognized "inborn error of metabolism." It is a familial disease characterized clinically by an early onset of anorexia, vomiting, mental and motor retardation, and, occasionally, hypertonicity and convulsions. In most cases, the disease is fatal in a few weeks, but rarely, longer survival, up to 7 years, has occurred. The diagnosis is suggested clinically by a peculiar odor in the urine resembling that of maple syrup.1 Biochemically, the disease is characterized by elevated plasma levels of leucine, isoleucine, and valine, and an increased excretion of their ketoacids in the urine.2,3 A deficiency in the oxidative decarboxylation of these ketoacids has been demonstrated in the white blood cells of an infant with maple syrup urine disease.4 The pathological changes in the brain have been reported in 2 instances by Menkes, Hurst, and Craig.1 In one, Case 3,1