Pearls & Oy-sters: Delayed Response to Pyridoxine in Pyridoxine-Dependent Epilepsy

Area of Science:

• Biochemistry
• Genetics
• Neurology

Background:

• Inborn errors of metabolism encompass genetic disorders, including pyridoxine-dependent epilepsy (PDE), a cause of neonatal-onset epilepsy.
• PDE results from biallelic pathogenic variants in the ALDH7A1 gene, often presenting as refractory neonatal seizures and status epilepticus.

Observation:

• A case of a full-term neonate with PDE is presented.
• Seizure cessation occurred within hours of intravenous pyridoxine (vitamin B6) administration.
• However, significant improvement in EEG background and clinical encephalopathy was delayed by 5 days.

Findings:

• Pyridoxine supplementation can lead to delayed clinical and EEG improvement in PDE.
• Gradual clinical improvement necessitates continued vitamin B6 treatment for several days.

Implications:

• This case highlights the importance of sustained pyridoxine supplementation in suspected PDE cases.
• Continued treatment is crucial until genetic testing confirms PDE or an alternative diagnosis is established.
• Early and prolonged vitamin B6 therapy is vital for managing neonatal seizures and encephalopathy in PDE.