Saturday, November 28, 2015

Epilepsy in Adults With Mitochondrial Disease: A Cohort Study

Cover image for Vol. 78 Issue 5

The genetics of epilepsy is in a revolution.
Do you have an unknown cause?
 It turns our that adults have mitochondrial disease too. - JR

Epilepsy in Adults With Mitochondrial Disease: A Cohort Study

  1. Roger G. Whittaker PhD1,*
  2. Helen E. Devine MRCP2
  3. Grainne S. Gorman MRCP2,
  4. Andrew M. Schaefer MRCP2
  5. Rita Horvath PhD3
  6. Yi Ng MRCP2
  7. Victoria Nesbitt MRCP2
  8. Nichola Z. Lax PhD2
  9. Robert McFarland PhD2
  10. Mark O. Cunningham PhD1
  11. Robert W. Taylor PhD, FRCPath2and
  12. Douglass M. Turnbull PhD2
Article first published online: 17 NOV 2015

DOI: 10.1002/ana.24525


The aim of this work was to determine the prevalence and progression of epilepsy in adult patients with mitochondrial disease.


We prospectively recruited a cohort of 182 consecutive adult patients attending a specialized mitochondrial disease clinic in Newcastle upon Tyne between January 1, 2005 and January 1, 2008. We then followed this cohort over a 7-year period, recording primary outcome measures of occurrence of first seizure, status epilepticus, stroke-like episode, and death.


Overall prevalence of epilepsy in the cohort was 23.1%. Mean age of epilepsy onset was 29.4 years. Prevalence varied widely between genotypes, with several genotypes having no cases of epilepsy, a prevalence of 34.9% in the most common genotype (m.3243A>G mutation), and 92.3% in the m.8344A>G mutation. Among the cohort as a whole, focal seizures, with or without progression to bilateral convulsive seizures, was the most common seizure type. Conversely, all of the patients with the m.8344A>G mutation and epilepsy experienced myoclonic seizures. Patients with the m.3243A>G mutation remain at high risk of developing stroke-like episodes (1.16% per year). However, although the standardized mortality ratio for the entire cohort was high (2.86), this ratio did not differ significantly between patients with epilepsy (2.96) and those without (2.83).


Epilepsy is a common manifestation of mitochondrial disease. It develops early in the disease and, in the case of the m.3243A>G mutation, often presents in the context of a stroke-like episode or status epilepticus. However, epilepsy does not itself appear to contribute to the increased mortality in mitochondrial disease. Ann Neurol 2015

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