Diagnosis of pyridoxine-dependent seizures in a nineteen-year-old patient.

Although a diagnosis of pyridoxine-dependent seizures may commonly be delayed, this case involves an extremely late diagnosis with associated morbidity. Our patient received pyridoxine during the neonatal period, in conjunction with other antiepileptic drugs that masked its effect. This patient also underwent ventriculoperitoneal shunting, which complicated the diagnosis. Pyridoxine was continued with other antiepileptic drugs, without definite recognition of its therapeutic relationship. Pyridoxine-dependent seizures were finally recognized at age 19 years when the patient manifested refractory status epilepticus, several days after wisdom tooth removal (and discontinuing oral medications including pyridoxine and phenobarbital before surgery). The diagnosis was only established via genetic testing. Our patient highlights the difficulty in diagnosing this rare seizure type and its potential importance in refractory epilepsy.