Včasná diagnostika mnestických poruch u neurodegenerativních onemocnění

The ageing of the world's population means that the number of people with dementia, especially Alzheimer's disease (AD), will dramatically increase. That's why there is now a great effort to detect the presence of AD in its earliest predementia stages, in the stage of mild cognitive impairment (MCI), and particularly to identify individuals with amnestic syndrome of the hippocampal type (Ha-MCI - preclinical AD). The aim of our studies was to reveal whether spatial navigation testing could serve as an early biomarker of AD - whether spatial navigation is impaired early in patients with MCI, especially in Ha-MCI patients. We used the human analogue of the Morris water maze, the Hidden Goal Task (HGT), which is designed t! o separate two different modes of navigation, egocentric (body- centred, hippocampus independent) and allocentric (world-centred, hippocampus dependent), using a real space navigation setting called the Blue Velvet Arena (BVA), fully enclosed cylindrical arena, as well as a computer version of the BVA. Our results suggest that spatial navigation is impaired already in patients with amnestic MCI, who are more likely to progress to AD, especially in those with amnestic syndrome of the hippocampal type. The Ha-MCI patients presented severe spatial navigation impairment similar to that seen in...Department of NeurologyNeurologická klinika2. lékařská fakultaSecond Faculty of Medicin

Different Profiles of Spatial Navigation Deficits In Alzheimer's Disease Biomarker-Positive Versus Biomarker-Negative Older Adults With Amnestic Mild Cognitive Impairment.

Background: Spatial navigation impairment is a promising cognitive marker of Alzheimer's disease (AD) that can reflect the underlying pathology. Objectives: We assessed spatial navigation performance in AD biomarker positive older adults with amnestic mild cognitive impairment (AD aMCI) vs. those AD biomarker negative (non-AD aMCI), and examined associations between navigation performance, MRI measures of brain atrophy, and cerebrospinal fluid (CSF) biomarkers. Methods: A total of 122 participants with AD aMCI (n = 33), non-AD aMCI (n = 31), mild AD dementia (n = 28), and 30 cognitively normal older adults (CN) underwent cognitive assessment, brain MRI (n = 100 had high-quality images for volumetric analysis) and three virtual navigation tasks focused on route learning (body-centered navigation), wayfinding (world-centered navigation) and perspective taking/wayfinding. Cognitively impaired participants underwent CSF biomarker assessment [amyloid-β1-42, total tau, and phosphorylated tau181 (p-tau181)] and amyloid PET imaging (n = 47 and n = 45, respectively), with a subset having both (n = 19). Results: In route learning, AD aMCI performed worse than non-AD aMCI (p < 0.001), who performed similarly to CN. In wayfinding, aMCI participants performed worse than CN (both p ≤ 0.009) and AD aMCI performed worse than non-AD aMCI in the second task session (p = 0.032). In perspective taking/wayfinding, aMCI participants performed worse than CN (both p ≤ 0.001). AD aMCI and non-AD aMCI did not differ in conventional cognitive tests. Route learning was associated with parietal thickness and amyloid-β1-42, wayfinding was associated with posterior medial temporal lobe (MTL) volume and p-tau181 and perspective taking/wayfinding was correlated with MRI measures of several brain regions and all CSF biomarkers. Conclusion: AD biomarker positive and negative older adults with aMCI had different profiles of spatial navigation deficits that were associated with posterior MTL and parietal atrophy and reflected AD pathology

Obrazowanie tensora dyfuzji u pacjentów z chorobą Alzheimera i łagodnymi zaburzeniami poznawczymi

A wide range of imaging studies provides growing support for the potential role of diffusion tensor imaging (DTI) in evaluating microstructural white matter integrity in Alzheimer disease (AD) and mild cognitive impairment (MCI). Our review aims to present DTI principles, post-processing and analysis frameworks and to report the results of particular studies. The distribution of AD-related white matter abnormalities is widely discussed in the light of deteriorated connectivity within certain tracts due to secondary white matter degeneration; primary alterations are also assumed to contribute to the pattern. The question whether it is more effective to assess the whole-brain diffusion or to directly concentrate on specific regions remains an interesting issue. Assessing white matter microstructure alterations, as evaluated by group-level differences of tensor-derived parameters, may be a promising neuroimaging tool for differential diagnosis between AD, MCI and other cognitive disorders, as well as being particularly helpful in the interpretation of underlying pathological processes.Rosnąca liczba badań naukowych wskazuje na znaczenie obrazowania tensora dyfuzji (DTI) w ocenie mikrostrukturalnej integralności istoty białej w chorobie Alzheimera (ChA) i łagodnych zaburzeniach poznawczych (ŁZP). W niniejszej pracy przeglądowej omówiono zasady obróbki danych oraz analizy DTI i przedstawiono wyniki poszczególnych badań prezentujących różne modele charakterystycznych dla ChA zmian w istocie białej. Szeroko dyskutowane jest rozmieszczenie uszkodzeń w istocie białej, głównie w odniesieniu do wtórnego zwyrodnienia poszczególnych włókien wskutek zaniku istoty szarej lub pierwotnego zwyrodnienia istoty białej. Interesujący i nierozstrzygnięty pozostaje dylemat, czy bardziej efektywne jest obrazowanie zmian dyfuzji w całym mózgu, czy skupianie się na konkretnych strukturach. Zastosowanie DTI w ocenie mikrostrukturalnych zmian zachodzących w istocie białej mózgu może być obiecującym narzędziem w różnicowaniu pomiędzy ChA, ŁZP i innymi zaburzeniami poznawczymi; jest szczególnie przydatne przy interpretacji leżących u ich podłoża procesów patologicznych

Comparative study of CuO supported on CeO2, Ce0.8Zr0.2O2 and Ce0.8Al0.2O2 based catalysts in the CO-PROX reaction

CuO supported on CeO2, Ce0.8Zr0.2O2 and Ce0.8Al0.2O2 based catalysts (6%wt Cu) were synthesized and tested in the preferential oxidation of CO in a H2-rich stream (CO-PROX). Nanocrystalline supports, CeO2 and solid solutions of modified CeO2 with zirconium and aluminum were prepared by a freeze-drying method. CuO was supported by incipient wetness impregnation and calcination at 400 C. All catalysts exhibit high activity in the CO-PROX reaction and selectivity to CO2 at low reaction temperature, being the catalyst supported on CeO2 the more active and stable. The influence of the presence of CO2 and H2O was also studied

Spatial navigation deficits — overlooked cognitive marker for preclinical Alzheimer disease?

Detection of incipient Alzheimer disease (AD) pathophysiology is critical to identify preclinical individuals and target potentially disease-modifying therapies towards them. Current neuroimaging and biomarker research is strongly focused in this direction, with the aim of establishing AD fingerprints to identify individuals at high risk of developing this disease. By contrast, cognitive fingerprints for incipient AD are virtually non-existent as diagnostics and outcomes measures are still focused on episodic memory deficits as the gold standard for AD, despite their low sensitivity and specificity for identifying at-risk individuals. This Review highlights a novel feature of cognitive evaluation for incipient AD by focusing on spatial navigation and orientation deficits, which are increasingly shown to be present in at-risk individuals. Importantly, the navigation system in the brain overlaps substantially with the regions affected by AD in both animal models and humans. Notably, spatial navigation has fewer verbal, cultural and educational biases than current cognitive tests and could enable a more uniform, global approach towards cognitive fingerprints of AD and better cognitive treatment outcome measures in future multicentre trials. The current Review appraises the available evidence for spatial navigation and/or orientation deficits in preclinical, prodromal and confirmed AD and identifies research gaps and future research priorities

Early diagnostic of mnestic disorders in neurodegenerative diseases

The ageing of the world's population means that the number of people with dementia, especially Alzheimer's disease (AD), will dramatically increase. That's why there is now a great effort to detect the presence of AD in its earliest predementia stages, in the stage of mild cognitive impairment (MCI), and particularly to identify individuals with amnestic syndrome of the hippocampal type (Ha-MCI - preclinical AD). The aim of our studies was to reveal whether spatial navigation testing could serve as an early biomarker of AD - whether spatial navigation is impaired early in patients with MCI, especially in Ha-MCI patients. We used the human analogue of the Morris water maze, the Hidden Goal Task (HGT), which is designed t! o separate two different modes of navigation, egocentric (body- centred, hippocampus independent) and allocentric (world-centred, hippocampus dependent), using a real space navigation setting called the Blue Velvet Arena (BVA), fully enclosed cylindrical arena, as well as a computer version of the BVA. Our results suggest that spatial navigation is impaired already in patients with amnestic MCI, who are more likely to progress to AD, especially in those with amnestic syndrome of the hippocampal type. The Ha-MCI patients presented severe spatial navigation impairment similar to that seen in..

Early diagnostic of mnestic disorders in neurodegenerative diseases

The ageing of the world's population means that the number of people with dementia, especially Alzheimer's disease (AD), will dramatically increase. That's why there is now a great effort to detect the presence of AD in its earliest predementia stages, in the stage of mild cognitive impairment (MCI), and particularly to identify individuals with amnestic syndrome of the hippocampal type (Ha-MCI - preclinical AD). The aim of our studies was to reveal whether spatial navigation testing could serve as an early biomarker of AD - whether spatial navigation is impaired early in patients with MCI, especially in Ha-MCI patients. We used the human analogue of the Morris water maze, the Hidden Goal Task (HGT), which is designed t! o separate two different modes of navigation, egocentric (body- centred, hippocampus independent) and allocentric (world-centred, hippocampus dependent), using a real space navigation setting called the Blue Velvet Arena (BVA), fully enclosed cylindrical arena, as well as a computer version of the BVA. Our results suggest that spatial navigation is impaired already in patients with amnestic MCI, who are more likely to progress to AD, especially in those with amnestic syndrome of the hippocampal type. The Ha-MCI patients presented severe spatial navigation impairment similar to that seen in..

Spatial navigation questionnaires as a supportive diagnostic tool in early Alzheimer’s disease

Summary: Impaired spatial navigation is early marker of Alzheimer’s disease (AD). We examined ability of self- and informant-reported navigation questionnaires to discriminate between clinically and biomarker-defined participants, and associations of questionnaires with navigation performance, regional brain atrophy, AD biomarkers, and biomarker status. 262 participants (cognitively normal, with subjective cognitive decline, amnestic mild cognitive impairment [aMCI], and mild dementia) and their informants completed three navigation questionnaires. Navigation performance, magnetic resonance imaging volume/thickness of AD-related brain regions, and AD biomarkers were measured. Informant-reported questionnaires distinguished between cognitively normal and impaired participants, and amyloid-β positive and negative aMCI. Lower scores were associated with worse navigation performance, greater atrophy in AD-related brain regions, and amyloid-β status. Self-reported questionnaire scores did not distinguish between the groups and were weakly associated with navigation performance. Other associations were not significant. Informant-reported navigation questionnaires may be a screening tool for early AD reflecting atrophy of AD-related brain regions and AD pathology

Clock Drawing Test and the diagnosis of amnestic mild cognitive impairment: Can more detailed scoring systems do the work?

Dataset accompanying a publication https://doi.org/10.1080/13803395.2014.97723

Famous Landmark Identification in Amnestic Mild Cognitive Impairment and Alzheimer\u27s Disease

Background: Identification of famous landmarks (FLI), famous faces (FFI) and recognition of facial emotions (FER) is affected early in the course of Alzheimer’s disease (AD). FFI, FER and FLI may represent domain specific tasks relying on activation of distinct regions of the medial temporal lobe, which are affected successively during the course of AD. However, the data on FFI and FER in MCI are controversial and FLI domain remains almost unexplored. Objectives: To determine whether and how are these three specific domains impaired in head to head comparison of patients with amnestic MCI (aMCI) single domain (SD-aMCI) and multiple domain (MD-aMCI). We propose that FLI might be most reliable in differentiating SD-aMCI, which is considered to be an earlier stage of AD pathology spread out, from the controls. Patients and Methods: A total of 114 patients, 13 with single domain (SD–aMCI) and 30 with multiple domains (MD–aMCI), 29 with mild AD and 42 controls underwent standard neurological and neuropsychological evaluations as well as tests of FLI, FER and FFI. Results: Compared to the control group, AD subjects performed worse on FFI (p = 0.020), FER (p,0.001) and FLI (p,0.001), MD-aMCI group had significantly worse scores only on FLI (p = 0.002) and approached statistical significance on FER (0.053). SD-aMCI group performed significantly worse only on FLI (p = 0.028) compared to controls. Conclusions: Patients with SD-aMCI had an isolated impairment restricted to FLI, while patients with MD–aMCI showed impairment in FLI as well as in FER. Patients with mild dementia due to AD have more extensive impairment of higher visual perception. The results suggest that FLI testing may contribute to identification of patients at risk of AD. We hypothesize that clinical examination of all three domains might reflect the spread of the disease from transentorhinal cortex, over amygdala to fusiform gyrus