SciELO - Scientific Electronic Library Online

 
vol.72 issue10Psychogenic nonepileptic seizures and psychogenic movement disorders: two sides of the same coin? author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand

Journal

Article

Indicators

Related links

Share


Arquivos de Neuro-Psiquiatria

Print version ISSN 0004-282X

Abstract

LORENZONI, Paulo José et al. When should MERRF (myoclonus epilepsy associated with ragged-red fibers) be the diagnosis?. Arq. Neuro-Psiquiatr. [online]. 2014, vol.72, n.10, pp.803-811. ISSN 0004-282X.  http://dx.doi.org/10.1590/0004-282X20140124.

Myoclonic epilepsy associated with ragged red fibers (MERRF) is a rare mitochondrial disorder. Diagnostic criteria for MERRF include typical manifestations of the disease: myoclonus, generalized epilepsy, cerebellar ataxia and ragged red fibers (RRF) on muscle biopsy. Clinical features of MERRF are not necessarily uniform in the early stages of the disease, and correlations between clinical manifestations and physiopathology have not been fully elucidated. It is estimated that point mutations in the tRNALys gene of the DNAmt, mainly A8344G, are responsible for almost 90% of MERRF cases. Morphological changes seen upon muscle biopsy in MERRF include a substantive proportion of RRF, muscle fibers showing a deficient activity of cytochrome c oxidase (COX) and the presence of vessels with a strong reaction for succinate dehydrogenase and COX deficiency. In this review, we discuss mainly clinical and laboratory manifestations, brain images, electrophysiological patterns, histology and molecular findings as well as some differential diagnoses and treatments.

Keywords : MERRF; mitochondrial; epilepsy; myoclonus; myopathy.

        · abstract in Portuguese     · text in English     · English ( pdf )