Pyridoxine-dependent seizures: an atypical case

Abstract

Pyridoxine-dependent seizure (PDS) is a readily treatable cause of intractable seizures in childhood (1). Not more than 100 cases have been reported in the English language indexed journals. Delay in initiation of treatment could result in permanent mental handicap. It is generally recommended that a trial of pyridoxine should be given in all cases of intractable seizures below the age of 3 years (2). We report a case of 4-year-old boy with mental retardation and intractable seizures who, responded well to pyridoxine. This report emphasizes the importance of considering PDS in children with intractable seizures beyond 3 years. A 4-year-old boy was admitted to the pediatrics intensive care unit with status epilepticus. He was born to non-consanguineous parents with an Apgar score of 10 at 5 minutes. There was no family history of seizures or mental impairment. Child attained social smile at 4 months, turned over at 7 months, walked independently at 20 months, and started saying 2-3 words at 3 years. Generalized seizures (partial seizures with generalization and myoclonus) started at the age 2 years. Various antiepileptic drugs either as monotherapy or in combination resulted mild reduction in seizure frequency. At 4 years he could speak 3-4 words, could indicate toilet needs and walk with minimal difficulty. His vision and hearing were normal. Electroencephalogram (EEG) showed multifocal spike and wave discharges. MRI of brain showed mild diffuse cerebral atrophy with prominent ventricles. The following tests were normal or negative: hemogram, serum calcium and phosphorous, blood thyroid hormone profile, renal and liver function tests, serum ammonia, blood arterial pH, plasma organic acids, and urine homocysteine, reducing substances and organic acids. He was continued