Neuropediatrics 2008; 39(1): 8-13
DOI: 10.1055/s-2008-1076737
Original Article

© Georg Thieme Verlag KG Stuttgart · New York

Epilepsy and Respiratory Chain Defects in Children with Mitochondrial Encephalopathies

D. S. Khurana 1 , L. Salganicoff 1 , J. J. Melvin 1 , E. F. Hobdell 1 , I. Valencia 1 , H. H. Hardison 1 , H. G. Marks 1 , W. D. Grover 1 , A. Legido 1
  • 1Section of Neurology, St Christopher’ s Hospital for Children, Department of Pediatrics, Drexel University College of Medicine, Philadelphia, USA
Further Information

Publication History

received 16.05.2007

accepted 18.03.2008

Publication Date:
26 May 2008 (online)

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Abstract

Objective: The purpose of this study was to determine the relationship between epilepsy and respiratory chain defects in children with mitochondrial encephalopathies (ME).

Study Design: We conducted a retrospective review of the medical records of children referred for evaluation of an ME. Only patients assigned a definite diagnosis of ME using modified Walker criteria and with a respiratory chain defect were included. Clinical data pertaining to the ME and epilepsy type were collected. Mitochondria were isolated by subcellular fractionation from a vastus lateralis muscle biopsy and studies were performed using polarographic and spectroscopic techniques for the quantitative determination of NADH and cytochrome components of the respiratory chain.

Results: A total of 38 children with ME were identified. Seizures were present in 61%. Sixteen of 23 children with epilepsy (70%) had refractory epilepsy associated with a progressive encephalopathy. Children with epilepsy had a significantly higher incidence of complex I defects than children without epilepsy (p<0.01). Complex III and IV defects were significantly higher in patients without epilepsy (p<0.01 and p<0.05, respectively) than in those with epilepsy.

Conclusions: Epilepsy is an important component of ME. The higher incidence of complex I defects in patients with epilepsy suggests a possible relationship between mitochondrial oxidative stress dysfunction and epileptogenic process.