Cognitive functions in myoclonic epilepsy with ragged red fibres – a case report


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Journal of Epileptology

Foundation of Epileptology

Subject: Medicine


eISSN: 2300-0147





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VOLUME 23 , ISSUE 1 (June 2015) > List of articles

Cognitive functions in myoclonic epilepsy with ragged red fibres – a case report

Martyna Domańska * / Emilia J. Sitek / Michał Schinwelski / Maria Mazurkiewicz-Bełdzińska / Agnieszka Matheisel / Jarosław Sławek

Keywords : MERRF, epilepsy, myoclonus, mitochondrial diseases, cognitive impairment

Citation Information : Journal of Epileptology. Volume 23, Issue 1, Pages 69-74, DOI:

License : (CC BY 4.0)

Received Date : 24-January-2015 / Accepted: 30-April-2015 / Published Online: 05-May-2015

Open Access article funded by EJS was supported by a scholarship for young researchers from Polish Ministry of Science and Higher



Introduction. Myoclonic epilepsy with ragged red fibers (MERRF) is a rare, progressive mitochondrial disease affecting multiple systems, including the central nervous system. Typical MERRF symptoms include: myoclonus, epileptic seizures, ataxia and cognitive decline. In mitochondrial diseases selective cognitive impairment or generalized decline, called mitochondrial dementia, is usually diagnosed.

Description of case. We present the case of an 18-year-old patient with progressive neurological symptoms such as multifocal myoclonus, cerebellar syndrome (gait impairment, intention tremor, ataxia and dysmetria). The diagnosis of MERRF was confirmed at the age of 16. Neuropsychological examination showed slowing of verbal learning and deficient spontaneous recall with improvement on recognition as well as low verbal fluency.

Discussion. The authors discuss differential diagnosis of mitochondrial diseases (MIDs) in respect to cognitive function impairment and, in particular, to dementia: MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes), KSS (Kearns-Sayre syndrome), NARP syndrome (neuropathy, ataxia, and retinitis pigmentosa and ptosis). The authors emphasize importance of comprehensive neuropsychological assessment in differential diagnosis of MIDs.

Conclusion. Mild and selective cognitive impairment was identified. The type and degree of cognitive function impairment is not sufficient to diagnose dementia in this particular case of MERRF. Comprehensive neuropsychological assessment is crucial in MID in order to provide the patient with useful recommendations for education planning.

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