824 research outputs found
Cognition in myotonic dystrophy type 1: a 5-year follow-up study
No full textBackground and purpose: Studies on cognitive decline in myotonic dystrophy type 1 (DM1) are characterized by conflicting results. The purpose of the present study was to analyse possible decline in classical/adult onset DM1 at a 5-year follow-up and to explore the correlation with disease-related and demographic factors. Methods: Patients with DM1 (n = 37) were examined with a comprehensive neuropsychological test battery yielding measures on memory, attention, verbal, visuospatial and executive functions. Assessment of muscle impairment and CTG repeat expansion size was performed. Results: A majority of the participants (65%) performed worse at follow-up. Compared to normative data, patients scored significantly worse on tests measuring memory, attention, visuospatial construction and verbal ability. Neither CTG repeat size nor muscle impairment related to cognitive decline. However, age at onset and disease duration were correlated with the number of tests in which performance was below 1 SD at both baseline and follow-up examination. Conclusions: Measurements show that classical/adult onset DM1 is characterized by cognitive decline. Both earlier onset and longer duration of the disease are indicative of more cognitive deficits.
Cognitive decline in Myotonic dystrophy type 1 (DM1)
No full textBackground: Myotonic dystrophy type 1 (DM1) is a disorder associated with deficits in facial emotion recognition ability and social interaction skills 1, 2, 3. This study aimed to explore an important function associated with facial analysis and social interplay - the ability to remember and to recognize faces.
Methods: Thirty-three persons with adult onset DM1 and thirty healthy controls performed a facial memory task included in the Rivermead Behavioral Memory Test-Extended (RBMT-E) 4. Scores in this task were correlated with duration of the disease, CTG repeat expansion size as measured in blood and results on neuropsychological tests.
Results: Deficits in facial memory ability were significantly (P 475 repeats, failure in facial memory ability was associated with larger repeats and longer duration of the disease. Furthermore, a significant association between general visuoconstructive ability and facial memory in the DM1 group (but not in healthy controls) indicated the use of compensatory visual analytic strategies. These strategies involved a focus on details in favor of holistic analyses.
Conclusions: In summary, this study is the first to show facial memory deficits and prosopagnosia in adult onset DM1. Thus, the ability to recognize faces is a basic prerequisite in social interplay, this finding adds an important clue on understanding social interaction associated with the disease
Therapeutic Approaches to Prion Diseases : In Vitro Studies with Tetracycline Compounds
No full textPrion diseases are a group of fatal neurodegenerative disorders of humans and animals which may be sporadic or inherited in origin and can be transmitted. The emergence of a new variant of CJD in the UK, which is proposed to be causally linked to BSE, has increased the urgency to identify and develop therapeutic compounds due to fear of a possible future epidemic. In this study we showed that tetracyline prevents aggregation and acquisition of protease resistance of PrP peptides, disrupts PrP peptide aggregates, and abolishes the neurotoxicity and astroglial proliferation induced by PrP peptides in vitro
Anaemia increases the risk of dementia in cognitively intact elderly.
No full textAlthough cross-sectional studies found an association between anaemia and dementia, longitudinal studies provided contradictory results. We hypothesize that anaemia might increase the risk of developing dementia because of chronic brain hypo-oxygenation. Using baseline data from a community-based longitudinal study, the Kungsholmen Project, Stockholm, Sweden, we clinically followed 1435 non demented subjects aged 75-95 years for 3 years to detect incident dementia cases (DSM-III-R criteria). Subjects that fulfilled WHO criteria for anaemia, baseline haemoglobin concentration; 130 g/L (men) and 120 g/L (women), had a higher hazard ratios (HR) of developing dementia 3 years later (HR 1.6, 95% CI: 1.1-2.4). In persons with good baseline cognition (MMSE>or=26, n=1139), the association was stronger and still significant after adjustments for conditions potentially related to anaemia and dementia, such as chronic diseases, inflammatory markers, and indicators of nutritional status. The HR was increased even when different haemoglobin cut offs for anaemia definition were used. Thus, anaemia is suggested to be a new potential modifiable risk factor for dementia
Recognition of false alarms in fall detection systems
No full textFalls are a major cause of hospitalization and injury-related deaths among the elderly population. The detrimental effects of falls, as well as the negative impact on health services costs, have led to a great interest on fall detection systems by the health-care industry. The most promising approaches are those based on a wearable device that monitors the movements of the patient, recognizes a fall and triggers an alarm. Unfortunately such techniques suffer from the problem of false alarms: some activities of daily living are erroneously reported as falls, thus reducing the confidence of the user. This paper presents a novel approach for improving the detection accuracy which is based on the idea of identifying specific movement patterns into the acceleration data. Using a single accelerometer, our system can recognize these patterns and use them to distinguish activities of daily living from real falls; thus the number of false alarms is reduced
Late-life body mass index and dementia incidence: nine-year follow-up data from the Kungsholmen Project
No full textOBJECTIVES: To describe the association between late-life body mass index (BMI) and dementia development with a time perspective and to investigate the effect of weight changes on dementia incidence.
DESIGN: Three-, 6-, and 9-year follow-up study.
SETTING: The Kungsholmen Project.
PARTICIPANTS: One thousand two hundred fifty-five subjects aged 75 and older with baseline BMI data available.
MEASUREMENTS: Cox-regression models were used to estimate hazard ratios (HRs) for dementia detected at different risk periods in relation to baseline BMI. The association between BMI changes and development of dementia after 3 and 6 years was also analyzed.
RESULTS: Subjects with a BMI of 25.0 kg/m2 or higher had a lower risk of developing dementia than subjects with a BMI of 20.0 to 24.9 (HR=0.75, 95% confidence interval (CI)=0.59-0.96), even when cases occurring only during the last follow-up period (6-9 years after BMI assessment) were included (HR=0.66. 95% CI=0.40-1.07). Severe BMI loss (>10%) was related to a greater risk of dementia, but this association was present only for dementia cases detected in the subsequent 3 years (HR=2.18, 95% CI=1.27-3.74).
CONCLUSION: This study does not confirm that being overweight in late life is a risk factor for dementia, although a protective effect for a BMI greater than 25.0 is suggested. In addition, BMI loss is confirmed as a marker of incipient dementia. The findings suggest that, from a clinical perspective, the cognitive profile of elderly persons with unexplained weight loss should be considered and that being moderately overweight at older ages might be indicative of good health status
Proximity ligation assay reveals both pre- A nd postsynaptic localization of the APP-processing enzymes ADAM10 and BACE1 in rat and human adult brain
No full textBackground: Synaptic degeneration and accumulation of amyloid β-peptides (Aβ) are hallmarks of the Alzheimer diseased brain. Aβ is synaptotoxic and produced by sequential cleavage of the amyloid precursor protein (APP) by the β-secretase BACE1 and by γ-secretase. If APP is instead cleaved by the α-secretase ADAM10, Aβ will not be generated. Although BACE1 is considered to be a presynaptic protein and ADAM10 has been reported to mainly localize to the postsynaptic density, we have previously shown that both ADAM10 and BACE1 are highly enriched in synaptic vesicles of rat brain and mouse primary hippocampal neurons. Results: Here, using brightfield proximity ligation assay, we expanded our previous result in primary neurons and investigated the in situ synaptic localization of ADAM10 and BACE1 in rat and human adult brain using both pre- A nd postsynaptic markers. We found that ADAM10 and BACE1 were in close proximity with both the presynaptic marker synaptophysin and the postsynaptic marker PSD-95. The substrate APP was also detected both pre- A nd postsynaptically. Subcellular fractionation confirmed that ADAM10 and BACE1 are enriched to a similar degree in synaptic vesicles and as well as in the postsynaptic density. Conclusions: We show that the α-secretase ADAM10 and the β-secretase BACE1 are located in both the pre- A nd postsynaptic compartments in intact brain sections. These findings increase our understanding of the regulation of APP processing, thereby facilitating development of more specific treatment strategies
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