PYRIDOXINE-DEPENDENT SEIZURES ASSOCIATED WITH WHITE-MATTER ABNORMALITIES

Pyridoxine-dependent seizures are a disorder of GABA metabolism probab ly due to a defective binding of pyridoxal phosphate coenzyme (PALP) w ith glutamate decarboxylase (GAD), the rate-limiting enzyme in GABA sy nthesis. The resulting GABA deficiency causes severe epilepsy in infan cy. We report on a boy with seizures starting soon after birth, and on ly controlled by pyridoxine at pharmacological dosages. After two mont hs without seizures, a CT scan showed hypodense white matter in fronta l and occipital lobes suggestive of a retarded or defective myelinatio n. We are not aware of other descriptions of such morphological abnorm alities in a patient with this disorder.