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Interictal High Frequency Oscillations Detected with Simultaneous Magnetoencephalography and Electroencephalography as Biomarker of Pediatric Epilepsy
10:22

Interictal High Frequency Oscillations Detected with Simultaneous Magnetoencephalography and Electroencephalography as Biomarker of Pediatric Epilepsy

Published on: December 6, 2016

High-frequency rhythmic cortical myoclonus in a long-surviving patient with nonketotic hypergylcemia

Massimo Mastrangelo1, Laura Canafoglia, Silvana Franceschetti

  • 1Pediatric Neurology Unit, V. Buzzi Hospital, A.O. ICP, Milan, Italy.

Journal of Child Neurology
|January 10, 2008
PubMed

Insights

This case study presents an 11-year-old girl with nonketotic hyperglycinemia, showing that persistent myoclonus may evolve into rhythmic cortical myoclonus, even after treatment for seizures.

Area of Science:

  • Neurology
  • Metabolic Disorders
  • Pediatrics

Background:

  • Nonketotic hyperglycinemia (NKH) typically presents with early myoclonic encephalopathy in neonates.
  • Early treatment with sodium benzoate and dextromethorphan can control seizures in NKH.

Observation:

  • An 11-year-old girl with NKH, successfully treated for seizures, continued to experience myoclonus.
  • Multifocal rhythmic myoclonic jerks, enhanced by motor activity and occurring at gamma frequency, were observed.
  • Electroencephalography-electromyography coherence analysis suggested a cortical origin for the myoclonic jerks.

Findings:

  • The patient's persistent myoclonus demonstrated a cortical origin.
  • The observed rhythmic myoclonic jerks occurred at gamma frequency.

Implications:

  • Rhythmic cortical myoclonus may represent a late-evolving manifestation of nonketotic hyperglycinemia.
  • This case highlights the potential for diverse neurological presentations in NKH beyond the neonatal period.
  • Understanding the evolution of NKH symptoms is crucial for long-term patient management.

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