ABSTRACT

“Myoclonic Epilepsy with Ragged Red Fibers” (MERFF) is a progressive myoclonic epileptic syndrome characterized by myoclonus, tonic-clonic seizures, dementia and cerebellar signs. Myopathy, neuropathy, optic atrophy, deafness, cardiomyopathy, pigmented retinopathy, short stature, lactic acidosis or diabetes mellitus can accompany this syndrome. Mean life expectancy for these patients are approximately 10 years, without any known specific treatment. We report a 37 years-old female patient with a late diagnosis of MERFF. The clinical presentation consisted of myoclonus and epileptic seizures with a good medical control. Skeletal muscle biopsy revealed multiple ragged-red fibers, containing subsarcolemmal and intracytoplasmic mitochondrial aggregates without glucogen or neutral lipid deposits.