Mitochondrial Causes of Epilepsy: Evaluation, Diagnosis, and Treatment

Hannah E. Steele, MBBS, MRCP; Patrick F. Chinnery, PhD, FRCP, FRCPath


Semin Neurol. 2015;35(3):300-309. 

In This Article

Epilepsy in Nonsyndromic Mitochondrial Disease

Nonsyndromic mitochondrial disease occurs frequently—particularly early in the disease course. Reflecting this, 50% to 70% of children manifesting seizures in the context of a respiratory chain defect (RCD) have a nonsyndromic diagnosis.[2,3,11,12] In contrast, similar adult patients have nonsyndromic features in approximately 40% of cases.[3]

Chevellier studied 165 adults and children with confirmed mitochondrial disease, of whom roughly a third (n = 60) had had a previously identified seizure.[2] Most patients included in the study had neither a (mitochondrial) syndromic (68%) nor molecular genetic diagnosis (72%). Perhaps surprisingly, 70% of this population was well controlled with treatment—although the proportion of these with and without a mitochondrial syndromic diagnosis is unknown. This is in keeping with the proportion of individuals with epilepsy of all causes who can achieve seizure freedom with appropriate medication.[45]