Clinical, fluorine-18 labeled 2-fluoro-2-deoxyglucose positron emission tomography (FDG PET), MRI of the brain and biochemical observations in a patient with 4-hydroxybutyric aciduria; a progressive neurometabolic disease

We report a five-year-old boy with 4-hydroxybutyric aciduria. The child pre sented with global developmental delay, severe hypotonia and myoclonic seiz ures. The urine 4-hydroxybutyric acid was 1038 times that of normal, and ot her organic acids related to its further metabolism were also increased. El ectroencephalography showed findings indicative of cerebral dysfunction. Ho wever, other neurophysiological studies were normal. Clinical improvement w as observed after the administration of vigabatrin and dextromethorphan. Ma gnetic resonance imaging of the brain revealed cerebellar vermin atrophy an d subtle white matter changes in the cerebral hemispheres. Fluorine-18 labe led 2-fluoro-2-deoxyglucose positron emission tomographic (FDG PET) scan of the brain showed a marked decrease in the cerebellar metabolism, probably related to atrophy of cerebellar vermis and secondary cerebellar deafferent ation. FDG PET scan is found to be of value in the understanding and assess ment of brain functional alterations. It may be useful in monitoring and op timizing treatment strategies of this rare disease. (C) 2000 Elsevier Scien ce B.V. All rights reserved.