MELAS: a neuropsychological and radiological follow-up study

Sartor, Heino; Loose, Rainer; Tucha, Oliver; Klein, Helmfried E.; Lange, Klaus W.

doi:10.1034/j.1600-0404.2002.01089.x

Cited by 36 publications

(20 citation statements)

References 8 publications

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“…This profile is consistent with the earlier misdiagnosis of developmental dyslexia as the other areas of cognition were well preserved. In previous reports of patients with mitochondrial disorders, language function was either not reported (Lang et al, 1995;Turconi, 1999;Kauffman, 2004) or impaired in some cases (Kartsounis, 1992;Sartor, 2002;Bosbach, 2003).…”

Section: Discussionmentioning

confidence: 92%

“…Diagnosis of mitochondrial dementia (Finsterer, 2009) was excluded. Mild and/or focal cognitive deficits were also described in previous reports of patients with mitochondrial disease (Kartsounis et al, 1992;Turconi et al, 1999;Sartor et al, 2002;Bosbach et al, 2003) and only in few reported cases mitochondrial dementia was diagnosed (Lang et al, 1995). MELAS patients are often described in the literature as those most cognitively impaired, but often they were not always diagnosed with mitochondrial dementia as they presented with focal cognitive impairments (Lang et al, 1995;Sartor et.…”

Section: Discussionmentioning

confidence: 97%

“…Attention deficits were attributed to the patients with MID in most of previous reports (Kartsounis, 1992;Lang, 1995;Turconi, 1999;Sartor, 2002;Bosbach, 2003).…”

Section: Discussionmentioning

confidence: 97%

“…In many studies of MIDs, Wechsler Intelligence Scales (WISC or WAIS) were used to assess cognition (Karsounis et al, 1992;Turconi et al, 1999;Sartor et al, 2002;Bosbach et al, 2003). However, Wechsler intelligence scales do not evaluate important areas of cognition, such as episodic memory or executive functions (Lezak, 1988;Ardila, 1999).…”

Section: Discussionmentioning

confidence: 99%

“…Most data on cognitive function in mitochondrial disease come either from studies of patients with MELAS (Mitochondrial encephalomyopathy, lactic acidosis and strokelike episodes) or from mixed patient cohorts (Kartsounis et al, 1992;Turconi et al, 1999;Kaufmann et al, 2004). Slowed information processing seems to be the most prominent finding in a majority of cases (Finsterer, 2009), followed by a variety of focal cognitive deficits (visuospatial, language, memory impairment) and executive dysfunction (Kartsounis et al, 1992;Turconi et al, 1999;Sartor et al, 2002;Bosbach et al, 2003). It is unclear to what extent these findings are applicable to patients with MERFF.…”

Section: Introductionmentioning

confidence: 99%

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

Domańska¹,

Sitek²,

Schinwelski³

et al. 2015

Journal of Epileptology

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SUMMARYIntroduction. 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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Section: Discussionmentioning

confidence: 92%

Section: Discussionmentioning

confidence: 97%

“…Attention deficits were attributed to the patients with MID in most of previous reports (Kartsounis, 1992;Lang, 1995;Turconi, 1999;Sartor, 2002;Bosbach, 2003).…”

Section: Discussionmentioning

confidence: 97%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

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

Domańska¹,

Sitek²,

Schinwelski³

et al. 2015

Journal of Epileptology

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Visual memory failure presages conversion to MELAS phenotype

Leaffer

Vivo

Engelstad

et al. 2022

Ann Clin Transl Neurol

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Objective: To examine the correlation between verbal and visual memory function and correlation with brain metabolites (lactate and N-Acetylaspartate, NAA) in individuals with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS). Methods: Memory performance and brain metabolites (ventricular lactate, occipital lactate, and occipital NAA) were examined in 18 MELAS, 58 m.3243A > G carriers, and 20 familial controls. Measures included the Selective Reminding Test (verbal memory), Benton Visuospatial Retention Test (visual memory), and MR Spectroscopy (NAA, Lactate). ANOVA, chi-squared/Fisher's exact tests, paired t-tests, Pearson correlations, and Spearman correlations were used. Results: When compared to carriers and controls, MELAS patients had the: (1) most impaired memory functions (Visual: p = 0.0003; Verbal: p = 0.02), (2) greatest visual than verbal memory impairment, (3) highest brain lactate levels (p < 0.0001), and (4) lowest brain NAA levels (p = 0.0003). Occipital and ventricular lactate to NAA ratios correlated significantly with visual memory performance (p ≤ 0.001). Higher lactate levels (p ≤ 0.01) and lower NAA levels (p = 0.0009) correlated specifically with greater visual memory dysfunction in MELAS. There was little or no correlation with verbal memory. Interpretation: Individuals with MELAS are at increased risk for impaired memory. Although verbal and visual memory are both affected, visual memory is preferentially affected and more clearly associated with brain metabolite levels. Preferential involvement of posterior brain regions is a distinctive clinical signature of MELAS. We now report a distinctive cognitive phenotype that targets visual memory more prominently and earlier than verbal memory. We speculate that this finding in carriers presages a conversion to the MELAS phenotype.

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Cognitive impairment in neuromuscular disorders

Bresolin

2006

Muscle and Nerve

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Several studies have suggested the presence of central nervous system involvement manifesting as cognitive impairment in diseases traditionally confined to the peripheral nervous system. The aim of this review is to highlight the character of clinical, genetic, neurofunctional, cognitive, and psychiatric deficits in neuromuscular disorders. A high correlation between cognitive features and cerebral protein expression or function is evident in Duchenne muscular dystrophy, myotonic dystrophy (Steinert disease), and mitochondrial encephalomyopathies; direct correlation between tissue-specific protein expression and cognitive deficits is still elusive in certain neuromuscular disorders presenting with or without a cerebral abnormality, such as congenital muscular dystrophies, congenital myopathies, amyotrophic lateral sclerosis, adult polyglucosan body disease, and limb-girdle muscular dystrophies. No clear cognitive deficits have been found in spinal muscular atrophy and facioscapulohumeral dystrophy.

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MELAS: a neuropsychological and radiological follow-up study

Cited by 36 publications

References 8 publications

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

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

Visual memory failure presages conversion to MELAS phenotype

Cognitive impairment in neuromuscular disorders

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