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1.
Brain ; 2024 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-39400198

RESUMO

White matter hyperintensities of presumed vascular origin (WMH) are associated with cognitive impairment and are a key imaging marker in evaluating brain health. However, WMH volume alone does not fully account for the extent of cognitive deficits and the mechanisms linking WMH to these deficits remain unclear. Lesion network mapping (LNM) enables to infer if brain networks are connected to lesions and could be a promising technique for enhancing our understanding of the role of WMH in cognitive disorders. Our study employed LNM to test the following hypotheses: (1) LNM-informed markers surpass WMH volumes in predicting cognitive performance, and (2) WMH contributing to cognitive impairment map to specific brain networks. We analyzed cross-sectional data of 3,485 patients from 10 memory clinic cohorts within the Meta VCI Map Consortium, using harmonized test results in 4 cognitive domains and WMH segmentations. WMH segmentations were registered to a standard space and mapped onto existing normative structural and functional brain connectome data. We employed LNM to quantify WMH connectivity to 480 atlas-based gray and white matter regions of interest (ROI), resulting in ROI-level structural and functional LNM scores. We compared the capacity of total and regional WMH volumes and LNM scores in predicting cognitive function using ridge regression models in a nested cross-validation. LNM scores predicted performance in three cognitive domains (attention/executive function, information processing speed, and verbal memory) significantly better than WMH volumes. LNM scores did not improve prediction for language functions. ROI-level analysis revealed that higher LNM scores, representing greater connectivity to WMH, in gray and white matter regions of the dorsal and ventral attention networks were associated with lower cognitive performance. Measures of WMH-related brain network connectivity significantly improve the prediction of current cognitive performance in memory clinic patients compared to WMH volume as a traditional imaging marker of cerebrovascular disease. This highlights the crucial role of network integrity, particularly in attention-related brain regions, improving our understanding of vascular contributions to cognitive impairment. Moving forward, refining WMH information with connectivity data could contribute to patient-tailored therapeutic interventions and facilitate the identification of subgroups at risk of cognitive disorders.

2.
Alzheimers Dement ; 20(4): 2980-2989, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38477469

RESUMO

INTRODUCTION: White matter hyperintensities (WMH) are associated with key dementia etiologies, in particular arteriolosclerosis and amyloid pathology. We aimed to identify WMH locations associated with vascular risk or cerebral amyloid-ß1-42 (Aß42)-positive status. METHODS: Individual patient data (n = 3,132; mean age 71.5 ± 9 years; 49.3% female) from 11 memory clinic cohorts were harmonized. WMH volumes in 28 regions were related to a vascular risk compound score (VRCS) and Aß42 status (based on cerebrospinal fluid or amyloid positron emission tomography), correcting for age, sex, study site, and total WMH volume. RESULTS: VRCS was associated with WMH in anterior/superior corona radiata (B = 0.034/0.038, p < 0.001), external capsule (B = 0.052, p < 0.001), and middle cerebellar peduncle (B = 0.067, p < 0.001), and Aß42-positive status with WMH in posterior thalamic radiation (B = 0.097, p < 0.001) and splenium (B = 0.103, p < 0.001). DISCUSSION: Vascular risk factors and Aß42 pathology have distinct signature WMH patterns. This regional vulnerability may incite future studies into how arteriolosclerosis and Aß42 pathology affect the brain's white matter. HIGHLIGHTS: Key dementia etiologies may be associated with specific patterns of white matter hyperintensities (WMH). We related WMH locations to vascular risk and cerebral Aß42 status in 11 memory clinic cohorts. Aß42 positive status was associated with posterior WMH in splenium and posterior thalamic radiation. Vascular risk was associated with anterior and infratentorial WMH. Amyloid pathology and vascular risk have distinct signature WMH patterns.


Assuntos
Arteriolosclerose , Demência , Substância Branca , Humanos , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Masculino , Substância Branca/patologia , Arteriolosclerose/patologia , Peptídeos beta-Amiloides/metabolismo , Demência/patologia , Imageamento por Ressonância Magnética
3.
Alzheimers Dement ; 19(6): 2420-2432, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36504357

RESUMO

INTRODUCTION: Impact of white matter hyperintensities (WMH) on cognition likely depends on lesion location, but a comprehensive map of strategic locations is lacking. We aimed to identify these locations in a large multicenter study. METHODS: Individual patient data (n = 3525) from 11 memory clinic cohorts were harmonized. We determined the association of WMH location with attention and executive functioning, information processing speed, language, and verbal memory performance using voxel-based and region of interest tract-based analyses. RESULTS: WMH in the left and right anterior thalamic radiation, forceps major, and left inferior fronto-occipital fasciculus were significantly related to domain-specific impairment, independent of total WMH volume and atrophy. A strategic WMH score based on these tracts inversely correlated with performance in all domains. DISCUSSION: The data show that the impact of WMH on cognition is location-dependent, primarily involving four strategic white matter tracts. Evaluation of WMH location may support diagnosing vascular cognitive impairment. HIGHLIGHTS: We analyzed white matter hyperintensities (WMH) in 3525 memory clinic patients from 11 cohorts The impact of WMH on cognition depends on location We identified four strategic white matter tracts A single strategic WMH score was derived from these four strategic tracts The strategic WMH score was an independent determinant of four cognitive domains.


Assuntos
Disfunção Cognitiva , Substância Branca , Humanos , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Imageamento por Ressonância Magnética , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/patologia , Cognição , Função Executiva , Testes Neuropsicológicos
4.
Neurobiol Dis ; 175: 105927, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36379394

RESUMO

BACKGROUND: C9orf72 repeat expansions have been observed in a wide variety of neurodegenerative disorders. The cut-off between normal and pathogenic alleles is not well established as repeat sizing methods are often semi-quantitative. However, intermediate alleles might influence disease prevalence and phenotype, as seen for other repeat expansion disorders. We aimed to further delineate the prevalence of small, intermediate and expanded C9orf72 alleles and elucidate their potential influence on the disease phenotype. METHODS: DNA derived from patients (n = 1804) and healthy individuals (n = 643) was obtained from multiple collectives in Austria. Genotyping was performed using a two-step PCR assay followed by Southern blotting. RESULTS: 3.4% of clinically diagnosed frontotemporal dementia (FTD; n = 5/147) cases and 0.8% of clinically diagnosed Alzheimer's disease (AD; n = 5/602) cases were carriers of a pathological C9orf72 repeat expansion. A significantly earlier disease onset was detected in expansion carriers compared to non-carriers in the FTD and AD cohorts (median 50 years, range 39-64 vs. median 64 years, range 36-92, p = 0.018 and median 63 years, range 54-71 vs. median 74 years, range 45-92, p = 0.006, respectively). C9orf72 intermediate alleles were significantly associated with cerebellar symptoms (p = 0.0004) and sensory deficits in the dementia cohort (p = 0.01). CONCLUSIONS: C9orf72 repeat expansion carriers showed earlier disease onset compared to non-carriers with clinical diagnosis of FTD and AD. Furthermore, C9orf72 intermediate repeats might modify the phenotypic expression in dementia.


Assuntos
Esclerose Lateral Amiotrófica , Demência Frontotemporal , Humanos , Expansão das Repetições de DNA/genética , Proteína C9orf72/genética , Demência Frontotemporal/genética , Demência Frontotemporal/patologia , Proteínas/genética , Fenótipo , Esclerose Lateral Amiotrófica/genética
5.
Medicina (Kaunas) ; 58(3)2022 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-35334608

RESUMO

Background and Objectives: The neurofilament light chain (NfL) is a biomarker for neuro-axonal injury in various acute and chronic neurological disorders, including Alzheimer's disease (AD). We here investigated the cross-sectional and longitudinal associations between baseline serum NfL (sNfL) levels and cognitive, behavioural as well as MR volumetric findings in the Prospective Dementia Registry Austria (PRODEM-Austria). Materials and Methods: All participants were clinically diagnosed with AD according to NINCDS-ADRDA criteria and underwent a detailed clinical assessment, cognitive testing (including the Mini Mental State Examination (MMSE) and the Consortium to Establish a Registry for Alzheimer's Disease (CERAD)), the neuropsychiatric inventory (NPI) and laboratory evaluation. A total of 237 patients were included in the study. Follow-up examinations were done at 6 months, 1 year and 2 years with 93.3% of patients undergoing at least one follow-up. We quantified sNfL by a single molecule array (Simoa). In a subgroup of 125 subjects, brain imaging data (1.5 or 3T MRI, with 1 mm isotropic resolution) were available. Brain volumetry was assessed using the FreeSurfer image analysis suite (v6.0). Results: Higher sNfL concentrations were associated with worse performance in cognitive tests at baseline, including CERAD (B = −10.084, SE = 2.999, p < 0.001) and MMSE (B = −3.014, SE = 1.293, p = 0.021). The sNfL levels also correlated with the presence of neuropsychiatric symptoms (NPI total score: r = 0.138, p = 0.041) and with smaller volumes of the temporal lobe (B = −0.012, SE = 0.003, p = 0.001), the hippocampus (B = −0.001, SE = 0.000201, p = 0.013), the entorhinal (B = −0.000308, SE = 0.000124, p = 0.014), and the parahippocampal cortex (B = −0.000316, SE = 0.000113, p = 0.006). The sNfL values predicted more pronounced cognitive decline over the mean follow-up period of 22 months, but there were no significant associations with respect to change in neuropsychiatric symptoms and brain volumetric measures. Conclusions: the sNfL levels relate to cognitive, behavioural, and imaging hallmarks of AD and predicts short term cognitive decline.


Assuntos
Doença de Alzheimer , Doença de Alzheimer/diagnóstico por imagem , Áustria/epidemiologia , Estudos Transversais , Humanos , Estudos Prospectivos , Sistema de Registros
6.
J Neural Transm (Vienna) ; 123(3): 297-316, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26411482

RESUMO

We analyzed the relation of several synchrony markers in the electroencephalogram (EEG) and Alzheimer's disease (AD) severity as measured by Mini-Mental State Examination (MMSE) scores. The study sample consisted of 79 subjects diagnosed with probable AD. All subjects were participants in the PRODEM-Austria study. Following a homogeneous protocol, the EEG was recorded both in resting state and during a cognitive task. We employed quadratic least squares regression to describe the relation between MMSE and the EEG markers. Factor analysis was used for estimating a potentially lower number of unobserved synchrony factors. These common factors were then related to MMSE scores as well. Most markers displayed an initial increase of EEG synchrony with MMSE scores from 26 to 21 or 20, and a decrease below. This effect was most prominent during the cognitive task and may be owed to cerebral compensatory mechanisms. Factor analysis provided interesting insights in the synchrony structures and the first common factors were related to MMSE scores with coefficients of determination up to 0.433. We conclude that several of the proposed EEG markers are related to AD severity for the overall sample with a wide dispersion for individual subjects. Part of these fluctuations may be owed to fluctuations and day-to-day variability associated with MMSE measurements. Our study provides a systematic analysis of EEG synchrony based on a large and homogeneous sample. The results indicate that the individual markers capture different aspects of EEG synchrony and may reflect cerebral compensatory mechanisms in the early stages of AD.


Assuntos
Doença de Alzheimer/fisiopatologia , Encéfalo/fisiopatologia , Sincronização Cortical/fisiologia , Idoso , Idoso de 80 Anos ou mais , Eletroencefalografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Processamento de Sinais Assistido por Computador
7.
Neuropsychobiology ; 71(3): 168-75, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25998702

RESUMO

BACKGROUND/AIMS: Depression is a highly prevalent disorder in elderly individuals. A genetic variant (rs6265) of the brain-derived neurotrophic factor (BDNF) impacting on emotion processing is known to increase the risk for depression. We aim to investigate whether intensive endurance sports might attenuate this genetic susceptibility in a cohort of elderly marathon athletes. METHODS: Fifty-five athletes and 58 controls were included. rs6265 of the BDNF gene was genotyped by the TaqMan method. Depressive symptoms were assessed by standardized self-rating tests (BDI = Beck Depression Inventory, GDS = Geriatric Depression Scale). RESULTS: In multivariable analysis of BDI and GDS scores, the interaction between group (athletes vs. controls) and genotypes ([C];[C] vs. [C];[T] + [T];[T]) was found to be statistically significant (BDI: p = 0.027, GDS: p = 0.013). Among [C];[C] carriers, merely controls had an increased relative risk of 3.537 (95% CI = 1.276-9.802) of achieving a subclinical depression score ≥10 on the BDI. There was no such effect in carriers of the [T] allele. In a multivariable binary logistic regression, genetic information, group (athletes/controls), but no information on rs6265 allele carrier status presented as a significant predictor of BDI scores ≥10. CONCLUSION: Physical exercise positively affects BDNF effects on mood. Since 66Met BDNF secretion is impaired, this effect seems to be much stronger in [C];[C] homozygous individuals expressing the 66Val variant. This confirms that genetic susceptibility to depressive symptoms can indeed be influenced by endurance sports in elderly people.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/genética , Depressão/genética , Depressão/prevenção & controle , Exercício Físico , Predisposição Genética para Doença/genética , Predisposição Genética para Doença/prevenção & controle , Idoso , Atletas , Fator Neurotrófico Derivado do Encéfalo/sangue , Estudos de Casos e Controles , Estudos de Coortes , Depressão/sangue , Depressão/psicologia , Feminino , Predisposição Genética para Doença/psicologia , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Testes Psicológicos , Estatísticas não Paramétricas , Inquéritos e Questionários
8.
Int Psychogeriatr ; 27(3): 357-66, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25382659

RESUMO

BACKGROUND: Impaired awareness of memory deficits has been recognized as a common phenomenon in Alzheimer's disease (AD) and research is now increasingly focusing on awareness in groups at risk for future dementia. This study aimed to determine whether levels of awareness differ among healthy elderly people and patients with subjective cognitive decline (SCD), amnestic and non-amnestic subtypes of mild cognitive impairment (aMCI, naMCI), Alzheimer's disease (AD) and Parkinson's disease (PD), to explore correlates of awareness and to establish frequencies of memory over- and underestimation within each diagnostic group. METHODS: 756 consecutive outpatients of a memory clinic and 211 healthy controls underwent thorough neuropsychological testing. Impairment of awareness was measured as the difference between subjective memory appraisals (16-item questionnaire on current memory-related problems in everyday life) and objective memory performance (15-item delayed recall task). Subgroups of over- and underestimators were classified using percentile ranks of controls. RESULTS: At group level, awareness significantly decreased along the naMCI→aMCI→AD continuum, with naMCI patients showing a tendency towards overestimation of memory dysfunction. PD patients showed accurate self-appraisals as long as memory function was largely unaffected. However, there was a considerable between-group overlap in awareness scores. Furthermore, different correlates of awareness were observed depending on the diagnostic group. In general, unawareness seems to be associated with decreased cognitive performance in various domains (especially memory), higher age and lower levels of depression and self-reported functional impairment. CONCLUSION: Impaired awareness is an important symptom in aMCI. Yet, given the considerable variability in awareness scores, longitudinal studies are required to evaluate their predictive power.


Assuntos
Doença de Alzheimer/psicologia , Transtornos Cognitivos/psicologia , Disfunção Cognitiva/psicologia , Transtornos da Memória/psicologia , Doença de Parkinson/psicologia , Humanos
9.
J Sport Exerc Psychol ; 37(6): 637-45, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26866771

RESUMO

A single nucleotide variant within the promoter of the 5-hydroxytryptamine1A (5HT1A) receptor, rs6295, is part of a binding site for the transcription factor. We aimed to ascertain whether the rs6295 mediates the effect of exercise on depressive mood in elderly endurance athletes. We prospectively enrolled 55 elderly athletes (marathon runners/bicyclists) and 58 controls. In a controlled, univariate model, an interaction between the [C]-allele and physical activity indicated that only among athletes, the variant resulting in an imperfect NUDR binding site was associated with a lower depression score. Hence, athletes presented with a significantly lower relative risk of achieving a suspicious depression score among carriers of at least one [C]-allele. Our results suggest that the positive effect of physical exercise on depressive mood might be mediated by the 5HT1A receptor and the extent of this protective effect seems to be enhanced by the [C]-allele of the rs6295 variant.


Assuntos
Atletas/psicologia , Depressão/genética , Resistência Física/genética , Polimorfismo de Nucleotídeo Único/genética , Receptor 5-HT1A de Serotonina/genética , Idoso , Alelos , Proteínas de Ligação a DNA , Feminino , Humanos , Masculino , Proteínas Nucleares/metabolismo , Escalas de Graduação Psiquiátrica , Receptor 5-HT1A de Serotonina/metabolismo , Corrida/psicologia , Fatores de Transcrição
10.
PLoS One ; 19(8): e0307111, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39141602

RESUMO

Alzheimer's disease (AD) imposes a major burden on affected individuals, their caregivers and health-care systems alike. Though quite many risk factors for disease progression have been identified, there is a lack of prospective studies investigating the interplay and predictive value of a wide variety of patient variables associated with cognitive deterioration (defined as key feature of AD progression). Study participants were patients with probable and possible AD, that were assessed at four time points over a period of two years (T1-T4). The main results were threefold: (i) over time, significant changes were observed regarding patients' cognitive functioning, activities of daily living and caregiver load (but not depression, pain, neuropsychiatric symptoms); (ii) intercorrelations between caregiver load and patients' cognitive and functional variables were high, correlation patterns remaining rather stable across time; (iii) cognitive functioning at T4 was best predicted by patients' age, sex, atrial fibrillation and activities of daily living at T1; and (iv) across all four assessment points, cognitive functioning was best predicted by time (i.e., disease duration), age, sex, activities of daily living and depression. Overall, even in early stages of AD and during a short two-year period, functional changes were significant and tightly intertwined with caregiver load, thus stressing the need to consider caregiver load when diagnosing and treating patients with AD. A novel and clinically relevant finding is that even in early stages of AD, cognitive deterioration was best predicted by a combination of patients' demographic, somatic and functional variables.


Assuntos
Atividades Cotidianas , Doença de Alzheimer , Cuidadores , Progressão da Doença , Humanos , Doença de Alzheimer/fisiopatologia , Doença de Alzheimer/psicologia , Masculino , Feminino , Idoso , Estudos Prospectivos , Cuidadores/psicologia , Idoso de 80 Anos ou mais , Cognição/fisiologia , Sistema de Registros , Disfunção Cognitiva/fisiopatologia , Testes Neuropsicológicos , Pessoa de Meia-Idade , Depressão , Fatores de Risco
11.
medRxiv ; 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38586023

RESUMO

Introduction: White matter hyperintensities of presumed vascular origin (WMH) are associated with cognitive impairment and are a key imaging marker in evaluating cognitive health. However, WMH volume alone does not fully account for the extent of cognitive deficits and the mechanisms linking WMH to these deficits remain unclear. We propose that lesion network mapping (LNM), enables to infer if brain networks are connected to lesions, and could be a promising technique for enhancing our understanding of the role of WMH in cognitive disorders. Our study employed this approach to test the following hypotheses: (1) LNM-informed markers surpass WMH volumes in predicting cognitive performance, and (2) WMH contributing to cognitive impairment map to specific brain networks. Methods & results: We analyzed cross-sectional data of 3,485 patients from 10 memory clinic cohorts within the Meta VCI Map Consortium, using harmonized test results in 4 cognitive domains and WMH segmentations. WMH segmentations were registered to a standard space and mapped onto existing normative structural and functional brain connectome data. We employed LNM to quantify WMH connectivity across 480 atlas-based gray and white matter regions of interest (ROI), resulting in ROI-level structural and functional LNM scores. The capacity of total and regional WMH volumes and LNM scores in predicting cognitive function was compared using ridge regression models in a nested cross-validation. LNM scores predicted performance in three cognitive domains (attention and executive function, information processing speed, and verbal memory) significantly better than WMH volumes. LNM scores did not improve prediction for language functions. ROI-level analysis revealed that higher LNM scores, representing greater disruptive effects of WMH on regional connectivity, in gray and white matter regions of the dorsal and ventral attention networks were associated with lower cognitive performance. Conclusion: Measures of WMH-related brain network connectivity significantly improve the prediction of current cognitive performance in memory clinic patients compared to WMH volume as a traditional imaging marker of cerebrovascular disease. This highlights the crucial role of network effects, particularly in attentionrelated brain regions, improving our understanding of vascular contributions to cognitive impairment. Moving forward, refining WMH information with connectivity data could contribute to patient-tailored therapeutic interventions and facilitate the identification of subgroups at risk of cognitive disorders.

12.
Alzheimers Dement ; 9(4): 366-76, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23164551

RESUMO

BACKGROUND: Early detection of dementia is becoming more and more important owing to the advent of pharmacologic treatment. OBJECTIVE: The goals of this study were to establish prevalence of mild cognitive impairment (MCI) subtypes in an outpatient memory clinic cohort using two different modes of MCI determination. DESIGN: Consecutive patients complaining of cognitive problems who came to the memory outpatient clinic for assessment of a possible cognitive disorder were included in the study. SETTING: Academic medical center. PARTICIPANTS: Six hundred eighty consecutive patients complaining about cognitive problems who came to the memory outpatient clinic for assessment of a possible cognitive disorder and fulfilled the inclusion criteria were included in the study. For 676 patients, sufficient data for MCI classification were available. RESULTS: Categorizing MCI patients into MCI subtypes according to the minimum mode of MCI classification revealed the following results: 106 patients (15.7%) were categorized as cognitively healthy, whereas 570 patients (84.3%) met the criteria for MCI. MCI patients were subtyped as amnestic mild cognitive impairment (aMCI) single domain (31 patients; 4.6%), aMCI multiple domain (226 patients; 33.4%), non-aMCI single domain (125 patients; 18.5%), and non-aMCI multiple domain (188 patients; 27.8%). Categorizing MCI patients into MCI subtypes according to the mean mode of MCI classification revealed the following results: 409 patients (60.5%) were categorized as cognitively healthy, whereas 267 patients (39.5%) met the criteria for MCI. MCI patients were subtyped as aMCI single domain (47 patients; 6.9%), aMCI multiple domain (57 patients; 8.5%), non-aMCI single domain (97 patients; 14.3%), and non-aMCI multiple domain (66 patients; 9.8%). CONCLUSION: MCI diagnosis frequencies are substantially affected by the criteria used for estimation of MCI. The effect of modifying the presence of impairment on a single cognitive measure versus the presence of impairment on a mean composite score of a certain domain differed considerably, ranging from 39.5% to 84.3%, indicating the importance of the development of guidelines for operationalizing MCI.


Assuntos
Disfunção Cognitiva/epidemiologia , Testes Neuropsicológicos , Centros Médicos Acadêmicos/estatística & dados numéricos , Idoso , Doença de Alzheimer/epidemiologia , Amnésia/classificação , Amnésia/diagnóstico , Amnésia/epidemiologia , Área Sob a Curva , Áustria/epidemiologia , Disfunção Cognitiva/classificação , Disfunção Cognitiva/diagnóstico , Estudos de Coortes , Progressão da Doença , Função Executiva , Feminino , Humanos , Testes de Inteligência , Testes de Linguagem , Masculino , Memória Episódica , Rememoração Mental , Pessoa de Meia-Idade , Ambulatório Hospitalar/estatística & dados numéricos , Valor Preditivo dos Testes , Prevalência , Estudos Prospectivos , Curva ROC , Distúrbios da Fala/diagnóstico , Distúrbios da Fala/epidemiologia
13.
Clin EEG Neurosci ; 54(3): 316-326, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-34658289

RESUMO

Background: Functional (un-)coupling (task-related change of functional connectivity) between different sites of the brain is a mechanism of general importance for cognitive processes. In Alzheimer's disease (AD), prior research identified diminished cortical connectivity as a hallmark of the disease. However, little is known about the relation between the amount of functional (un-)coupling and cognitive performance and decline in AD. Method: Cognitive performance (based on CERAD-Plus scores) and electroencephalogram (EEG)-based functional (un-)coupling measures (connectivity changes from rest to a Face-Name-Encoding task) were assessed in 135 AD patients (age: M = 73.8 years; SD = 9.0). Of these, 68 patients (M = 73.9 years; SD = 8.9) participated in a follow-up assessment of their cognitive performance 1.5 years later. Results: The amounts of functional (un-)coupling in left anterior-posterior and homotopic interhemispheric connections in beta1-band were related to cognitive performance at baseline (ß = .340; p < .001; ß = .274; P = .001, respectively). For both markers, a higher amount of functional coupling was associated with better cognitive performance. Both markers also were significant predictors for cognitive decline. However, while patients with greater functional coupling in left anterior-posterior connections declined less in cognitive performance (ß = .329; P = .035) those with greater functional coupling in interhemispheric connections declined more (ß = -.402; P = .010). Conclusion: These findings suggest an important role of functional coupling mechanisms in left anterior-posterior and interhemispheric connections in AD. Especially the complex relationship with cognitive decline in AD patients might be an interesting aspect for future studies.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Idoso , Imageamento por Ressonância Magnética , Eletroencefalografia/métodos , Encéfalo , Progressão da Doença
14.
Neuroimage Clin ; 40: 103547, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38035457

RESUMO

INTRODUCTION: The spatial distribution of white matter hyperintensities (WMH) on MRI is often considered in the diagnostic evaluation of patients with cognitive problems. In some patients, clinicians may classify WMH patterns as "unusual", but this is largely based on expert opinion, because detailed quantitative information about WMH distribution frequencies in a memory clinic setting is lacking. Here we report voxel wise 3D WMH distribution frequencies in a large multicenter dataset and also aimed to identify individuals with unusual WMH patterns. METHODS: Individual participant data (N = 3525, including 777 participants with subjective cognitive decline, 1389 participants with mild cognitive impairment and 1359 patients with dementia) from eleven memory clinic cohorts, recruited through the Meta VCI Map Consortium, were used. WMH segmentations were provided by participating centers or performed in Utrecht and registered to the Montreal Neurological Institute (MNI)-152 brain template for spatial normalization. To determine WMH distribution frequencies, we calculated WMH probability maps at voxel level. To identify individuals with unusual WMH patterns, region-of-interest (ROI) based WMH probability maps, rule-based scores, and a machine learning method (Local Outlier Factor (LOF)), were implemented. RESULTS: WMH occurred in 82% of voxels from the white matter template with large variation between subjects. Only a small proportion of the white matter (1.7%), mainly in the periventricular areas, was affected by WMH in at least 20% of participants. A large portion of the total white matter was affected infrequently. Nevertheless, 93.8% of individual participants had lesions in voxels that were affected in less than 2% of the population, mainly located in subcortical areas. Only the machine learning method effectively identified individuals with unusual patterns, in particular subjects with asymmetric WMH distribution or with WMH at relatively rarely affected locations despite common locations not being affected. DISCUSSION: Aggregating data from several memory clinic cohorts, we provide a detailed 3D map of WMH lesion distribution frequencies, that informs on common as well as rare localizations. The use of data-driven analysis with LOF can be used to identify unusual patterns, which might serve as an alert that rare causes of WMH should be considered.


Assuntos
Disfunção Cognitiva , Substância Branca , Humanos , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Imageamento por Ressonância Magnética/métodos , Neuroimagem , Disfunção Cognitiva/patologia , Estudos Multicêntricos como Assunto
15.
Neuropsychiatr ; 35(1): 35-47, 2021 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-33123943

RESUMO

Older adults are particularly affected by the current COVID-19 (SARS-CoV-2) pandemic. The risk of dying from COVID-19 increases with age and is often associated with pre-existing health conditions. Globally, more than 50 million-in Austria currently approximately 140,000 people-suffer from dementia. The co-occurrence of dementia as a "pandemic of old age" together with the COVID-19 pandemic has a double impact on persons living with dementia and their caregivers. The COVID-19 pandemic poses major challenges for individuals with dementia and their caregivers: (1) People with dementia have limited access to information on COVID-19, may have difficulties with protective measures such as wearing masks and in remembering safety regulations. (2) People with dementia live alone or with their family, or are institutionalized. To reduce the chance of infection among older people in nursing homes, Austrian local authorities have banned visitors to nursing homes and long-term care facilities and implemented strict social-distancing measures. As a result, older people lost face-to-face contact with their family members, became isolated and social activities stopped. Consequently, anxiety, stress and serious concerns about infections among staff in nursing homes increased and they developed signs of exhaustion and burnout during the full lockdown of the facilities. Thus, due to the emerging COVID-19 crisis, the Austrian Alzheimer Association (Österreichische Alzheimer Gesellschaft, ÖAG) and international societies developed recommendations to support people living with dementia and their caregivers on various issues of physical and mental health.


Assuntos
Doença de Alzheimer , COVID-19 , Demência , Pandemias , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/terapia , Áustria , COVID-19/epidemiologia , Controle de Doenças Transmissíveis , Demência/terapia , Humanos , Guias de Prática Clínica como Assunto , SARS-CoV-2
16.
Brain Sci ; 11(11)2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34827490

RESUMO

MRI studies have consistently identified atrophy patterns in Alzheimer's disease (AD) through a whole-brain voxel-based analysis, but efforts to investigate morphometric profiles using anatomically standardized and automated whole-brain ROI analyses, performed at the individual subject space, are still lacking. In this study we aimed (i) to utilize atlas-derived measurements of cortical thickness and subcortical volumes, including of the hippocampal subfields, to identify atrophy patterns in early-stage AD, and (ii) to compare cognitive profiles at baseline and during a one-year follow-up of those previously identified morphometric AD subtypes to predict disease progression. Through a prospectively recruited multi-center study, conducted at four Austrian sites, 120 patients were included with probable AD, a disease onset beyond 60 years and a clinical dementia rating of ≤1. Morphometric measures of T1-weighted images were obtained using FreeSurfer. A principal component and subsequent cluster analysis identified four morphometric subtypes, including (i) hippocampal predominant (30.8%), (ii) hippocampal-temporo-parietal (29.2%), (iii) parieto-temporal (hippocampal sparing, 20.8%) and (iv) hippocampal-temporal (19.2%) atrophy patterns that were associated with phenotypes differing predominately in the presentation and progression of verbal memory and visuospatial impairments. These morphologically distinct subtypes are based on standardized brain regions, which are anatomically defined and freely accessible so as to validate its diagnostic accuracy and enhance the prediction of disease progression.

17.
Neuropsychiatr ; 24(1): 1-13, 2010.
Artigo em Alemão | MEDLINE | ID: mdl-20146915

RESUMO

Dementia has been associated with disturbed pain processing and an impaired ability to provide self-reported ratings on pain. Patients with cognitive impairment have been shown to receive pain treatment less frequently than cognitively unimpaired individuals. Comorbidity is common in patients with dementia and a major factor contributing to pain. This demonstrates that a structured evaluation and categorisation of pain is mandatory for the treatment of older patients and that care should be taken to note indirect signs of pain. The appropriate scales are available and we propagate their application. Multimodal pain therapy is superior to one-dimensional approaches. A discussion of the effects and interactions of the analgesics presently available for geriatric care forms an integral part of this review.


Assuntos
Analgésicos/uso terapêutico , Demência/psicologia , Medição da Dor/métodos , Dor/tratamento farmacológico , Dor/psicologia , Vias Aferentes/fisiopatologia , Idoso , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/epidemiologia , Doença de Alzheimer/fisiopatologia , Doença de Alzheimer/psicologia , Analgésicos/efeitos adversos , Analgésicos Opioides/efeitos adversos , Analgésicos Opioides/uso terapêutico , Encéfalo/fisiopatologia , Terapia Combinada , Comorbidade , Estudos Transversais , Demência/diagnóstico , Demência/epidemiologia , Demência/fisiopatologia , Demência Vascular/diagnóstico , Demência Vascular/epidemiologia , Demência Vascular/fisiopatologia , Demência Vascular/psicologia , Demência Frontotemporal/diagnóstico , Demência Frontotemporal/epidemiologia , Demência Frontotemporal/fisiopatologia , Demência Frontotemporal/psicologia , Humanos , Doença por Corpos de Lewy/diagnóstico , Doença por Corpos de Lewy/epidemiologia , Doença por Corpos de Lewy/fisiopatologia , Doença por Corpos de Lewy/psicologia , Nociceptores/fisiologia , Dor/epidemiologia , Limiar da Dor/efeitos dos fármacos , Limiar da Dor/fisiologia , Medula Espinal/fisiopatologia
18.
Neuropsychiatr ; 24(2): 67-87, 2010.
Artigo em Alemão | MEDLINE | ID: mdl-20605003

RESUMO

The Austrian Alzheimer Society developed evidence-based guidelines based on a systematic literature search and criteria-guided assessment with subsequent transparent determination of grades of clinical recommendation. The authors evaluated currently available therapeutic approaches for the most common forms of dementia and focused on diagnosis and pharmacological intervention, taking into consideration the situation in Austria. The purpose of these guidelines is the rational and cost-effective use of diagnostic and therapeutic measures in dementing illnesses. Users are physicians and all other providers of care for patients with dementia in Austria.


Assuntos
Demência/diagnóstico , Demência/tratamento farmacológico , Medicina Baseada em Evidências , Nootrópicos/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Aminoácidos/efeitos adversos , Aminoácidos/uso terapêutico , Antipsicóticos/efeitos adversos , Antipsicóticos/uso terapêutico , Inibidores da Colinesterase/efeitos adversos , Inibidores da Colinesterase/uso terapêutico , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/tratamento farmacológico , Estudos Transversais , Demência/epidemiologia , Demência/etiologia , Quimioterapia Combinada , Feminino , Ginkgo biloba , Humanos , Incidência , Estilo de Vida , Assistência de Longa Duração , Masculino , Adesão à Medicação , Memantina/efeitos adversos , Memantina/uso terapêutico , Pessoa de Meia-Idade , Extratos Vegetais/efeitos adversos , Extratos Vegetais/uso terapêutico , Dinâmica Populacional , Psicotrópicos/efeitos adversos , Psicotrópicos/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto
19.
J Alzheimers Dis ; 73(1): 125-133, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31744004

RESUMO

BACKGROUND: Neuropsychiatric symptoms (NPS) occur frequently in the course of Alzheimer's disease (AD) and are suspected to be associated with a faster dementia progression. Numerous reports have defined specific subsyndromes, summarized in clusters of items of the Neuropsychiatric Inventory (NPI). OBJECTIVE: This study investigated the influence of specific NPI subsyndromes and clinical patient characteristics on dementia progression. METHODS: Data of the prospective registry on dementia in Austria (PRODEM) were retrospectively analyzed. Cognitive functioning was determined at baseline and 2 yearly follow-up visits using the Mini-Mental State Examination (MMSE) and the Consortium to Establish a Registry for Alzheimer's dementia neuropsychological test battery (CERAD). To assess NPS, the NPI was used: NPI items were classified in three subsyndromes (psychotic cluster, behavioral cluster, emotional cluster). RESULTS: Out of the 662 included patients (mean age 76.4±8.4 years), 43% completed follow-up visits for two years. Significant correlation between higher scores in all three subsyndromes and worse cognitive performance were found for MMSE score, naming, and verbal fluency. Results of linear mixed model analysis revealed lower age and higher scores in the psychotic cluster as significant predictors of changes in MMSE with time. CONCLUSION: In this study, we report the influence of psychotic subsyndromes and lower age on faster MMSE decline in early AD. These results emphasize the importance of not only assessing but also differentiating neuropsychiatric symptoms in subsyndromes in the early stages of AD as a possible predictor of disease progression.


Assuntos
Doença de Alzheimer/psicologia , Transtornos Mentais/psicologia , Idoso , Idoso de 80 Anos ou mais , Antipsicóticos/uso terapêutico , Áustria , Progressão da Doença , Feminino , Humanos , Modelos Lineares , Masculino , Transtornos Mentais/complicações , Testes de Estado Mental e Demência , Testes Neuropsicológicos , Valor Preditivo dos Testes , Estudos Prospectivos , Transtornos Psicóticos/epidemiologia , Transtornos Psicóticos/psicologia , Sistema de Registros , Comportamento Verbal
20.
Aging (Albany NY) ; 12(15): 15478-15491, 2020 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-32706338

RESUMO

BACKGROUND: Dementia, and in particular Alzheimer's disease (AD), is a debilitating progressive disease with high prevalence in our society. Vitamin B12 and folate deficiency are potential modifiable risk factors. However, previous studies reported inconsistent results. RESULTS: The average concentrations of all biochemical markers were within the respective reference ranges. Cross-sectional and longitudinal analyses did not reveal significant associations between biochemical markers and cognitive function, global or regional brain volume, cortical thickness or cortical surface area, neither in controls nor in AD patients. CONCLUSIONS: Variations of direct and indirect markers of B12 and folate status are not associated with cognitive dysfunction and brain atrophy. METHODS: This retrospective study explored the association between biochemical markers of B12 and folate status, cognitive function and MRI-based brain atrophy in cognitive normal elderly (controls) and AD patients. Folate, total and active vitamin B12 and MMA were measured in blood samples from 378 controls and 217 AD patients. Neuropsychiatric tests capturing memory, executive function and visuopractical skills were performed in all participants. Brain atrophy was assessed by MRI in 155 controls and 217 AD patients. In a subset of participants cognitive testing (n=234) and MRI (n=182) was repeated after an average median between 1.25 and 6.25 years.


Assuntos
Doença de Alzheimer/sangue , Encéfalo/patologia , Cognição , Ácido Fólico/sangue , Vitamina B 12/sangue , Idoso , Idoso de 80 Anos ou mais , Atrofia/sangue , Áustria , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
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