CEREBRAL METABOLIC CHANGE AFTER TREATMENT IN BIOTINIDASE DEFICIENCY

A 13.5-year-old boy with biotinidase deficiency was studied 8 days bef ore and 5 months after biotin treatment by positron emission tomograph y (PET) and computerized electroencephalographic topography (CET). Wit h biotin treatment there was a marked improvement in the presenting sy mptom of loss of visual acuity and a more modest recovery in spastic q uadraparesis. By PET scanning, the relative metabolic rate for glucose was more than 2 standard deviations lower in the temporal and occipit al cortices than in adult or age-matched controls. With biotin treatme nt, these values rose to normal limits for both control groups. By CET , normalized EEG equivalent to the relative glucose metabolic rate sho wed asymmetric slowing in the left temporal and frontal regions before treatment, whereas none of the 32 leads exceeded normal limits of del ta, theta, alpha or beta after treatment. These results suggest a stro ng correlation between clinical, metabolic and electrical measures of brain function as related to biotin treatment in biotinidase deficienc y.