A term newborn develops seizures within the first 24 hours of life. Phenobarbitone, phenytoin, and midazolam fail to control them. Seizures cease completely within minutes of administering 50 mg of a single intravenous vitamin, and recur when it is withheld. Which vitamin was administered?

• A Thiamine
• B Folic acid
• C Riboflavin
• D Pyridoxine ✓

Explanation

Pyridoxine dependency is an autosomal recessive disorder presenting with intractable neonatal seizures that respond dramatically and specifically to intravenous pyridoxine 50 to 100 mg, and relapse when it is stopped. This diagnostic and therapeutic trial is the classical bedside test. Thiamine-responsive seizures exist but are far rarer and do not show this reproducible cessation-withdrawal pattern as their defining feature.

Reference: Nelson Textbook of Pediatrics, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.