In Alzheimer's disease (AD), the hippocampus is an early site of tau pathology and neurodegeneration. Histological studies have shown that lesions are not uniformly distributed within the hippocampus. Moreover, alterations of different hippocampal layers may reflect distinct pathological processes. 7 T MRI dramatically improves the visualization of hippocampal subregions and layers. In this study, we aimed to assess whether 7 T MRI can detect volumetric changes in hippocampal layers in vivo in patients with AD. We studied four AD patients and seven control subjects. MR images were acquired using a whole-body 7 T scanner with an eight channel transmit–receive coil. Hippocampal subregions were manually segmented from coronal T2*-weighted gradient echo images with 0.3 × 0.3 × 1.2 mm3 resolution using a protocol that distinguishes between layers richer or poorer in neuronal bodies. Five subregions were segmented in the region of the hippocampal body: alveus, strata radiatum, lacunosum and moleculare (SRLM) of the cornu Ammonis (CA), hilum, stratum pyramidale of CA and stratum pyramidale of the subiculum. We found strong bilateral reductions in the SRLM of the cornu Ammonis and in the stratum pyramidale of the subiculum (p < 0.05), with average cross-sectional area reductions ranging from −29% to −49%. These results show that it is possible to detect volume loss in distinct hippocampal layers using segmentation of 7 T MRI. 7 T MRI-based segmentation is a promising tool for AD research.
While A+/N+ patients had the clinical characteristics typically observed in AD, A+/N-patients had a different epidemiological pattern (higher frequency in men, no association with advanced age or lower MMSE). The SNAP profile was less frequent than previously reported in the general elderly population, suggesting that this profile is not a frequent cause of memory impairment in this population.
Some recent studies have highlighted a link between a favorable childhood environment and the strengthening of neuronal resilience against the changes that occur in natural aging neurodegenerative disease. Many works have assessed the factors-both internal and external-that can contribute to delay the phenotype of an ongoing neurodegenerative brain pathology. At the crossroads of genetic, environmental and lifestyle factors, these relationships are unified by the concept of cognitive reserve (CR). This review focuses on the protective effects of maintaining this CR through the cognitive aging process, and emphasizes the most essential time in life for the development and strengthening of this CR. The in-depth study of this research shows that early stimulation with regard to social and sensory interactions, contributes to the proper development of cognitive, affective and psychosocial capacities. Childhood thus appears to be the most active phase in the development of CR, and as such we hypothesize that this constitutes the first essential period of primary prevention of pathological aging and loss of cognitive capacities. If this hypothesis is correct, early stimulation of the environment would therefore be considered as a true primary prevention and a public health issue. The earlier identification of neurodevelopmental disorders, which can affect personal and professional development across the lifespan, could therefore have longer-term impacts and provide better protection against aging.
Objective: To compare the administration of neuropsychological tests by teleneuropsychology (TeleNP) and face to face (F-F) in order to determine the feasibility and reliability of TeleNP. Method: At the inclusion visit, all participants underwent a traditional F-F neuropsychological assessment as part of their standard care. Four months after inclusion, they were randomized to undergo an additional neuropsychological assessment either by F-F administration or by TeleNP. Results: A total of 150 adults with cognitive complaints, but with no major cognitive or sensorial impairment were included. At 4 months, 69 participants were randomized in the F-F arm and 71 in TeleNP arm (10 lost in the follow-up). The overall satisfaction was high: 87.1% in the TeleNP arm were “very satisfied”, and 82.9% indicated no preference between F-F and TeleNP. In agreement with previous data from the literature, neuropsychological assessments gave similar results across both administration conditions for a large majority of tests [Mini-Mental State Examination (MMSE), Free and Cued Selective Reminding Test (FCSRT) French version, Mahieux gestural praxis battery, Frontal Assessment Battery (FAB), time of completion of the Trail making Test (TMT) A and B, number of errors of the TMT B, Rey complex figure test, categorical et phonological verbal fluency tests] and minor differences for others [80-picture naming test (DO-80), FAB, Digit Span forward and backward and number of errors in the TMT A]. Conclusions: TeleNP is a promising method to be able to test patients as an alternative to F-F condition. Before this procedure can be generalized, it is now necessary to standardize the adaptation of certain tests and to test them in populations with more significant cognitive disorders.
Under the auspices of the Societe Francaise de Geriatrie et Gerontologie, a multi-disciplinary group of specialists in geriatrics, neurology, epidemiology, psychiatry, neuroradiology and nuclear medicine met with the aim of drawing up references on the methods for diagnosing and treating mild Alzheimer's disease. The critical analysis of international literature, conducted by Professor Bruno Vellas for the scientific committee, has served to support study of the latest knowledge in 2008. The multi-disciplinary group met on 14 and 15 May 2008 in order to set out the questions that this study must answer and to allocate draft studies. Thus, it has been possible to conduct a study focused on mild Alzheimer's disease, giving particular attention to diagnostic procedure, specific methods of treatment and the benefits of making a diagnosis.
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