Epilepsy in mitochondrial disorders.

OBJECTIVES: Information about epilepsy in mitochondrial disorders is scarce although a number or syndromic and non-syndromic mitochondrial disorders frequently manifest with focal or generalized seizures. Aim of the review was to describe epilepsy in syndromic and non-syndromic mitochondrial disorders with epilepsy as a dominant or collateral feature of the phenotype.
METHODS: Literature search via Pubmed using the key words "mitochondrial", "epilepsy", "seizures", and all acronyms of syndromic mitochondrial disorders.
RESULTS: Syndromic mitochondrial disorders obligatory associated with epilepsy include Alpers-Huttenlocher-syndrome (AHS), ataxia neuropathy spectrum (ANS), Leigh-syndrome, MELAS-syndrome, myoclonic epilepsy, myopathy, and sensory ataxia (MEMSA) syndrome, and MERRF-syndrome, Occasionally, epilepsy is a phenotypic feature in IOSCA, KSS, LHON, LBSL, or NARP, All types of seizures occur but most frequently generalized tonic-clonic seizures, partial seizures, myoclonic jerks, or West-syndrome was reported. Treatment of epilepsy in patients with mitochondrial disorders is not at variance from epilepsy of other causes but mitochondrion-toxicity of various antiepileptic drugs, such as valproic acid, carbamazepine etc. has to be considered to avoid severe complications or deterioration of the underlying disease.
CONCLUSIONS: Epilepsy is a common phenotypic feature of syndromic as well as non-syndromic mitochondrial disorders. Treatment of epilepsy in mitochondrial disorders is not at variance from treatment of epilepsy due to other causes but mitochondrion-toxic drugs should be avoided.