Leukoencephalopathy associated with a disturbance in the metabolism of polyols

In vivo proton magnetic resonance spectroscopy of the brain demonstrated highly elevated levels of arabitol and ribitol in a 14‐year‐old boy with a white matter disorder and neuropathy of unknown origin. These polyols also were shown to be elevated in body fluids, suggesting an inborn error in polyol metabolism. The strong plasma/cerebrospinal fluid/brain gradient, with concentrations increasing in that order, suggests a primary neurometabolic disorder. Thus far, a basic enzyme defect has not been identified.