Folinic Acid–Responsive Seizures Initially Responsive to Pyridoxine

This report presents a male who developed clonic seizures on the day he was born. The next day, the diagnosis of pyridoxine-dependent seizures was made. However, contradictory to this diagnosis, seizures reappeared despite treatment with pyridoxine. Seizures ceased after folinic acid was initiated. The clinical and biochemical characteristics of folinic acid–responsive seizures are reviewed. Treatment with folinic acid should be considered in neonatal seizures of unknown origin that do not respond to pyridoxine, or manifest a transient response to pyridoxine.