Non-convulsive status epilepticus secondary to valproic acid-induced hyperammonemic encephalopathy

Velioglu S. K., Gazioglu S.

ACTA NEUROLOGICA SCANDINAVICA, vol.116, no.2, pp.128-132, 2007 (SCI-Expanded, Scopus)

  • Publication Type: Article / Article
  • Volume: 116 Issue: 2
  • Publication Date: 2007
  • Doi Number: 10.1111/j.1600-0404.2006.00793.x
  • Journal Name: ACTA NEUROLOGICA SCANDINAVICA
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.128-132
  • Keywords: EEG, encephalopathy, hypermmonemia, non-convulsive status epilepticus, valproic acid, adverse effects, antiepileptic drugs, seizures, DRUGS, RATS
  • Karadeniz Technical University Affiliated: Yes

Abstract

ackground –Valproic acid (VPA) may induce hyperammonemic
encephalopathy. On the other hand, seizure-inducing effects of
antiepileptic drugs (AEDs) may be aparadoxical reaction or a result of
AED-induced encephalopathy (commonly induced by VPA).
Methods –We present the case of a 19-year-old male who developed
acute mental status changes consistent with encephalopathy evolving
into repetitive seizures with oral automatisms induced by relatively
small doses of VPA. Results –Although serum hepatic enzymes, such
as AST and ALT, were normal, serum ammonia concentration was
high,i.e.70lmol/l (normal range 9–33lmol/l). Administration of
VPA was discontinued immediatelyafter admission. The patient’s
condition improved during the second week of hospitalization and
ammonium levels returned to normal. Conclusion –In conclusion,
although uncommon, a possible induction of non-convulsive status
epilepticus by valproate-inducedhyperammonemic encephalopathy
should be taken into account and properly managed by
discontinuation of the drug

Background - Valproic acid (VPA) may induce hyperammonemic encephalopathy. On the other hand, seizure-inducing effects of antiepileptic drugs (AEDs) may be a paradoxical reaction or a result of AED-induced encephalopathy (commonly induced by VPA). Methods - We present the case of a 19-year-old male who developed acute mental status changes consistent with encephalopathy evolving into repetitive seizures with oral automatisms induced by relatively small doses of VPA. Results -, Although serum hepatic enzymes, such as AST and ALT, were normal, serum ammonia concentration was high, i.e. 70 mu mol/l (normal range 9-33 mu mol/l). Administration of VPA was discontinued immediately after admission. The patient's condition improved during the second week of hospitalization and ammonium levels returned to normal. Conclusion - In conclusion, although uncommon, a possible induction of non-convulsive status epilepticus by valproate-induced hyperammonemic encephalopathy should be taken into account and properly managed by discontinuation of the drug.