Myotonic dystrophy type 1 (DM1) has a wide phenotypic spectrum and potentially may affect central nervous system with mild to severe involvement. Our aim was to investigate grey matter (GM) and white matter (WM) structural alterations in a sample of adult-onset DM1 patients and to evaluate relationship with clinical and cognitive variables.Thirty DM1 patients underwent neuropsychological investigation and 3T-MRI protocol. GM and WM changes were evaluated calculating brain parenchymal fraction (BPF), voxel-based morphometry (VBM), white matter lesion load (LL% and Fazekas scale) and tract based spatial statistical (TBSS).Patients showed main impairment in tests exploring executive and mnesic domains with visuo-spatial involvement, significantly related to BPF. VBM revealed clusters of widespread GM reduction and TBSS revealed areas of decreased fractional anisotropy (FA) and increased radial diffusivity (RD), mean diffusivity (MD) and axial diffusivity (AD) in patients compared to a group of matched healthy controls. Multiple regression analyses showed areas of significant negative relationship between left temporal atrophy and verbal memory, between RD and mnesic and visuo-spatial cognitive domains, and between AD and verbal memory.TBSS results indicate that the involvement of normal appearance WM, beyond the signal changes detected with conventional MR imaging (Fazekas scale and LL%), was associated with neuropsychological deficit. These data suggest that disrupted complex neuronal networks can underlie cognitive-behavioural dysfunctions in DM1.

BackgroundMyotonic dystrophy type 1 (Steinert’s disease or DM1), the most common form of autosomal dominant muscular dystrophy in adults, is a multisystem disorder, affecting skeletal muscle as well as eyes, heart, gastrointestinal tract, endocrine system, and central nervous system, finally responsible of increasing disabilities and secondary social consequences. To date, DM1-related brain involvement represents a challenging field of research. It is well known that DM1 patients frequently present neuropsychological disturbances and psychiatric comorbidities among which reduced awareness of disease burden and its progression, also defined as anosognosia, is common in clinical practice, this leading to secondary misattribution of symptoms, delay in timely diagnostic procedures and low compliance to treatment.MethodsHere we present an observational cross sectional study in which disease-related cognitive dysfunctions and quality of life were assessed by a protocol finally designed to estimate the prevalence of disease awareness in a sample of 65 adult-onset DM1 patients.ResultsOur analysis showed that in DM1 patients several cognitive functions, including executive and mnesic domains with visuo-spatial involvement, were affected. The assessment of anosognosia revealed that a high percentage (51.6 %) of DM1 subjects was disease unaware. The reduced illness awareness occurs across different physical and life domains, and it appears more prominent in Activities and Independence domains investigated by the Individualized Neuromuscular Quality Of Life (INQoL) questionnaire. Moreover, the unawareness resulted significantly related (at p <0.05 and p < 0.01) to the performance failure in cognitive tests, specifically in the domains of visuo-spatial memory, cognitive flexibility and conceptualization.ConclusionsThe obtained data confirm, by a systematic analysis, what’s the common clinical perceiving of disease unawareness in Steinert’s disease, this related to the already known cognitive-behavioural impairment of frontal type in affected patients. We believe that a deep knowledge of this aspect will be useful for medical practice in the management of patients with DM1, also for guidance in occupational and social interventions, definition of outcome measures and in preparation of trial readiness.

Randomized clinical trials are necessary to establish efficacy and safety of drugs. Multicenter collaboration is essential for the advancement of therapy for mitochondrial disorders.

A number of evidences indicates oxidative stress as a relevant pathogenic factor in Alzheimer's disease (AD) and mild cognitive impairment (MCI). Considering its recognized major genetic risk factors in AD, apolipoprotein (APO E) has been investigated in several experimental settings regarding its role in the process of reactive oxygen species (ROS) generation. The aim of this work has been to evaluate possible relationships between APO E genotype and plasma levels of selected oxidative stress markers in both AD and MCI patients. APO E genotypes were determined using restriction enzyme analysis. Plasma levels of oxidative markers, advanced oxidation protein products, iron-reducing ability of plasma and, in MCI, activity of superoxide dismutases were evaluated using spectrophotometric analysis. We found, compared to controls, increased levels of oxidized proteins and decreased values of plasma-reducing capacity in both AD patients (p < 0.0001) and MCI patients (p < 0.001); the difference between AD and MCI patients was significant only for plasma-reducing capacity (p < 0.0001), the former showing the lowest values. Superoxide dismutase activity was reduced, although not at statistical level, in MCI compared with that in controls. E4 allele was statistically associated (p < 0.05) with AD patients. When comparing different APO E genotype subgroups, no difference was present, as far as advanced oxidation protein products and iron-reducing ability of plasma levels were concerned, between E4 and non-E4 carriers, in both AD and MCI; on the contrary, E4 carriers MCI patients showed significantly decreased (p < 0.05) superoxide dismutase activity with respect to non-E4 carriers. This study, in confirming the occurrence of oxidative stress in AD and MCI patients, shows how it can be related, at least for superoxide dismutase activity in MCI, to APO E4 allele risk factor.

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