Encephalopathy in an infant with infantile spasms: possible role of valproate toxicity.

Abstract

An infant presented with global developmental delay and infantile spasms. EEG was suggestive of hypsarrhythmia. She was started on sodium valproate, clonazepam and adrenocorticotropic hormone injection. After an initial improvement the child developed vomiting, altered sensorium and increase in frequency of seizures suggestive of encephalopathy. Valproate-induced hyperammonaemia or hepatic encephalopathy was considered and the drug was withheld following which there was a dramatic improvement. Paradoxically, the liver function tests and serum ammonia were normal. However, a complete reversal of encephalopathy, on withdrawal of the drug, strongly suggested an adverse drug reaction (ADR) due to valproic acid. Marginal elevation of serum valproic acid prompted us to use the Naranjo ADR probability score to confirm the diagnosis. This case highlights the fact that valproate toxicity can manifest with normal liver function and serum ammonia levels. This is the youngest reported case with this rare form of valproate-induced encephalopathy.

• Authors: Shobhana Sivathanu, Sowmya Sampath, Madhubala Veerasamy, Satheeshkumar Sunderkumar
• Journal: BMJ case reports (BMJ Case Rep) Vol. 2014 (Apr 15 2014) ISSN: 1757-790X [Electronic] England
• PMID: 24810446 (Publication Type: Case Reports, Journal Article)

Chemical References

• Anticonvulsants
• Clonazepam
• Valproic Acid
• Ammonia
• Adrenocorticotropic Hormone

Topics

• Adrenocorticotropic Hormone (therapeutic use)
• Ammonia (blood)
• Anticonvulsants (adverse effects, therapeutic use)
• Clonazepam (therapeutic use)
• Drug Therapy, Combination
• Female
• Humans
• Infant
• Liver Function Tests
• Neurotoxicity Syndromes (etiology)
• Spasms, Infantile (drug therapy)
• Valproic Acid (adverse effects, therapeutic use)