Intractable absence seizures in hyperinsulinism-hyperammonemia syndrome

Kousuke Nakano, Katsuhiro Kobayashi, Yoshiyuki Okano, Kazuyoshi Aso, Yoko Ohtsuka

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


A girl with intractable absence seizures and facial myoclonia at age 7 years was eventually diagnosed with hyperinsulinism-hyperammonemia syndrome because of hypoglycemia, hyperinsulinism, hyperammonemia, and the results of an oral l-leucine loading test. Her seizures occurred even during periods of relatively normal blood glucose levels, and were completely suppressed by diazoxide treatment only. Her diagnosis of hyperinsulinism-hyperammonemia syndrome was confirmed by a loss of sensitivity of glutamate dehydrogenase for guanosine 5′-triphosphate. Genetic studies identified the I444M mutation in the GLUD1 gene, which encodes glutamate dehydrogenase. This case illustrates the complex relationship between seizures and hypoglycemia in hyperinsulinism-hyperammonemia syndrome that can create diagnostic difficulties. The possibility of hyperinsulinism-hyperammonemia syndrome should be considered in patients with refractory absence seizures with myoclonia.

Original languageEnglish
Pages (from-to)119-122
Number of pages4
JournalPediatric Neurology
Issue number2
Publication statusPublished - Aug 2012

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health
  • Neurology
  • Developmental Neuroscience
  • Clinical Neurology


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