Journal of Pediatric Epilepsy 2023; 12(04): 140-143
DOI: 10.1055/s-0043-1770052
Case Report

Neonatal Status Epilepticus Secondary to Nonketotic Hyperglycinemia: Efficacy of Low-Dose Dextromethorphan

1   Department of Pediatric Neurology, Hospital Universitario 12 de Octubre, Madrid, Spain
Maite La-Vega Talbott
2   Department of Pediatric Neurology-Epilepsy Unit, Hospital Mount Sinai, New York, United States
› Author Affiliations


Nonketotic hyperglycinemia is a severe form of early onset epileptic encephalopathy caused by disturbances in the glycine cleavage system, leading to neurological damage attributed to overstimulation of the N-methyl-D-aspartate receptor. Although there are no interventions known to be effective in altering the natural history of nonketotic hyperglycinemia, it is very important that the clinician recognizes this disease and initiates early evaluation and treatment to attain the best possible outcome. Here we present a newborn diagnosed with a severe form of nonketotic hyperglycinemia with frequent myoclonic seizures, which were resistant to phenobarbital, levetiracetam, ketogenic diet, sodium benzoate, and perampanel. Dextromethorphan reduced epileptic myoclonic jerks and improved the background activity on the electroencephalogram.


Permission for publication was obtained from our institution’s Institutional Review Board.

Publication History

Received: 01 March 2023

Accepted: 09 May 2023

Article published online:
19 June 2023

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  • References

  • 1 Lu FL, Wang PJ, Hwu WL, Tsou Yau KI, Wang TR. Neonatal type of nonketotic hyperglycinemia. Pediatr Neurol 1999; 20 (04) 295-300
  • 2 Rossi S, Daniele I, Bastrenta P, Mastrangelo M, Lista G. Early myoclonic encephalopathy and nonketotic hyperglycinemia. Pediatr Neurol 2009; 41 (05) 371-374
  • 3 Cusmai R, Martinelli D, Moavero R. et al. Ketogenic diet in early myoclonic encephalopathy due to non ketotic hyperglycinemia. Eur J Paediatr Neurol 2012; 16 (05) 509-513
  • 4 Iqbal M, Prasad M, Mordekar SR. Nonketotic hyperglycinemia case series. J Pediatr Neurosci 2015; 10 (04) 355-358
  • 5 Daida A, Hamano SI, Ikemoto S. et al. Use of perampanel and a ketogenic diet in nonketotic hyperglycinemia: a case report. Neuropediatrics 2020; 51 (06) 417-420
  • 6 Bjoraker KJ, Swanson MA, Coughlin II CR. et al. Neurodevelopmental outcome and treatment efficacy of benzoate and dextromethorphan in siblings with attenuated nonketotic hyperglycinemia. J Pediatr 2016; 170: 234-239
  • 7 Hamosh A, McDonald JW, Valle D, Francomano CA, Niedermeyer E, Johnston MV. Dextromethorphan and high-dose benzoate therapy for nonketotic hyperglycinemia in an infant. J Pediatr 1992; 121 (01) 131-135
  • 8 Alemzadeh R, Gammeltoft K, Matteson K. Efficacy of low-dose dextromethorphan in the treatment of nonketotic hyperglycinemia. Pediatrics 1996; 97 (6 Pt 1): 924-926
  • 9 Daida A, Hamano SI, Ikemoto S. et al. Use of perampanel and a ketogenic diet in nonketotic hyperglycinemia: a case report. Neuropediatrics 2020; 51 (06) 417-420
  • 10 Nowak M, Chuchra P, Paprocka J. Nonketotic hyperglycinemia: insight into current therapies. J Clin Med 2022; 11 (11) 3027