Abstracts

Pyridoxine dependent seizures are rare, with fewer than 150 cases reported worldwide. The diagnosis has been difficult to confirm and has required a challenge-rechallenge approach in the past. Recently the genetic basis has been described as well as biochemical markers that may be used to confirm the suspected diagnosis in the newborn period. In the literature of this rare disorder, seizures are often described as generalized tonic-clonic., We report a case of confirmed pyridoxine-dependent seizures in a newborn and an analysis of the seizures with video-EEG correlation. We describe the confirmation of the diagnosis by measurement of serum pipecolic acid., The infant[apos]s clinical presentation was dominated by early onset irritability/encephalopathy within a few hours of delivery, and seizures which began at 22 hours of life. Seizures were described as generalized tonic-clonic by the neonatologists but on close analysis of video-EEG were either R or L-sided during clinical clonic seizures. In addition to clonic seizures, the infant had myoclonic, [ldquo]shuddering[rdquo] events associated with generalized EEG discharges but these too had a hemispheric predominance. The baby had a rapid resolution of the encephalopathy with a single dose of pyridoxine 50 mg. Diagnosis was confirmed by measurement of serum pipecolic acid., Pyridoxine-dependent seizures are a rare occurrence and are described in the literature as generalized tonic-clonic events in the majority of infants. Close analysis of video-EEG suggests that these are not generalized tonic-clonic seizures but partial seizures. Encephalopathy is an underemphasized feature and may obscure seizures or precede them. Rapid and reliable diagnosis can be accomplished with measurement of serum markers for the disorder, which remain elevated even after treatment. Genetic testing will be available in the near future as well. Outcome can depend on early identification and treatment and a low threshold for an empiric trial of pyridoxine in neonatal seizures should continue to be our practice.,