Neuropediatrics 2009; 40(3): 152
DOI: 10.1055/s-0029-1243186
Letter to the Editor

© Georg Thieme Verlag KG Stuttgart · New York

Epilepsy and Respiratory Chain Defects in Children

M. Castro-Gago, M. O. Blanco-Barca, J. Eirís-Puñal
Further Information

Publication History

Publication Date:
17 December 2009 (online)

Sir,

We have read with interest the article on epilepsy and respiratory chain defects in children with mitochondrial encephalopathies (ME) published in Neuropediatrics by Khurana et al. [2]. The authors described their study of 23 children with epilepsy and ME compared with another 15 children with ME without epilepsy. They concluded that the epilepsy is an important component of ME, and that the higher incidence observed of complex I defects in patients with epilepsy suggests a possible relationship between mitochondrial oxidative stress dysfunction and epileptogenic process. Their results and conclusions are concordant with those reported in Epilepsia by Lee et al. [3].

In 2006, we published in Pediatr Neurol [1] our clinical experience with the mitochondrial respiratory chain (MRC) disorders in 51 children. Considering clinical findings, 39% of the MRC disease patients (20/51), who represented 52.5% of all the patients with encephalopathic forms (20/38), manifested some form of epilepsy. In nine of these patients most epilepsy attacks were myoclonic: three patients with a clinical phenotype indicative of severe myoclonic epilepsy, two patients with non-specific myoclonic epilepsy (in one of whom the possibility of MERRF syndrome was excluded), and four patients with West syndrome. In regard to the remaining 11 patients, one developed early-onset infantile epileptic encephalopathy (Ohtahara syndrome), eight manifested generalized crises with non-specific characteristics, and two exhibited partial symptoms, with or without secondary generalization. Seven cases (35%) were deficient in complex IV, four cases (20%) were deficient in complex I, five cases (25%) were combined deficient in complex III and IV, one case (5%) was combined deficient in complex I and IV, one case (5%) was deficient in complex III, and another case (5%) was combined deficient in complex I, III and IV. In one patient the complex deficiency was unknown. The majority of patients had a non-specific encephalopathy, and only three patients presented a clearly defined clinical syndrome: two patients (10%) with Alpers-Huttenlocher syndrome, and one patient (5%) with Leigh syndrome.

We concur with the conclusion of Khurana et al. [2], that ME are an important cause of symptomatic childhood epilepsy. Therefore, this group of disorders should be considered and investigated in any child with an underlying encephalopathy and epilepsy of unknown origin.

M. Castro-Gago, M.O. Blanco-Barca, J. Eirís-Puñal

References

  • 1 Castro-Gago M, Blanco-Barca MO, Campos-González Y. et al . Epidemio­logy of pediatric mitocondrial respiratory chain disorders in northwest Spain.  Pediatr Neurol. 2006;  34 204-211
  • 2 Khurana DS, Salganicoff L, Melvin JJ. et al . Epilepsy and respiratory chain defects in children with mitochondrial encephalopathies.  Neuropediatrics. 2008;  39 8-13
  • 3 Lee YM, Kang HC, Lee JS. et al . Mitochondrial respiratory chain defects: underlying etiology in various epileptic conditions.  Epilepsia. 2008;  49 685-690

Correspondence

Dr. Manuel Castro-Gago

Servicio de Neuropediatría

Departamento de Pediatría Hospital Clínico Universitario

La Choupana s/n

15706-Santiago de Compostela

Spain

Phone: +34/981/951 121

Fax: +34/981/531 987

Email: manuel.castro.gago@usc.es

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