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INTRODUCTION: Comparison of tau (flortaucipir) positron emission tomography (FTP-PET) to autopsy is important to demonstrate the relationship of FTP-PET to neuropathologic findings. METHODS: Autopsies were performed on 26 participants who had antemortem FTP-PET. FTP-PET standardized uptake value ratios (SUVRs) were compared to autopsy diagnoses and Braak tangle stage. Quantitative tau burden was compared to regional FTP-PET signal. RESULTS: Participants with Braak stages of IV or greater had elevated FTP-PET signal. FTP-PET was elevated in participants with Alzheimer's disease. An FTP-PET SUVR cut point of 1.29 was determined to be optimal. Quantitative measurements of hippocampal and temporal lobe tau burden were highly correlated to FTP-PET signal (rho's from 0.61 to 0.70, P ≤ .02). DISCUSSION: Elevated FTP-PET reflects Braak IV or greater neuropathology. Participants with primary age-related tauopathy and hippocampal sclerosis did not show elevated FTP-PET signal. Secondary neuropathologic diagnoses of Alzheimer's disease neuropathologic change can lead to borderline elevated FTP-PET signal.
Assuntos
Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/patologia , Tomografia por Emissão de Pósitrons , Proteínas tau/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/metabolismo , Autopsia , Encéfalo/patologia , Feminino , Humanos , MasculinoRESUMO
INTRODUCTION: Our primary goal was to examine demographic and clinicopathologic differences across an ethnoracially diverse autopsy-confirmed cohort of Alzheimer's disease cases. METHODS: A retrospective study was conducted in the Florida Autopsied Multi-Ethnic cohort on 1625 Alzheimer's disease cases, including decedents who self-reported as Hispanic/Latino (n = 67), black/African American (n = 19), and white/European American (n = 1539). RESULTS: Hispanic decedents had a higher frequency of family history of cognitive impairment (58%), an earlier age at onset (median age of 70 years), longer disease duration (median of 12 years), and lower MMSE proximal to death (median of 4 points) compared with the other ethnoracial groups. Black decedents had a lower Braak tangle stage (stage V) and higher frequency of coexisting hippocampal sclerosis (21%); however, only hippocampal sclerosis differences survived adjustment for sex, age at onset, and disease duration. Neither Thal amyloid phase nor coexisting Lewy body disease differed across ethnoracial groups. DISCUSSION: Despite a smaller sample size, Hispanics demonstrated longer disease duration with Alzheimer's disease, but not greater lifespan. Neuropathologic differences across ethnoracial groups supported differences in tau pathology distribution and coexisting hippocampal sclerosis, which may impact biomarker studies.
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Doença de Alzheimer , Autopsia , Negro ou Afro-Americano/estatística & dados numéricos , Encéfalo/patologia , Hispânico ou Latino/estatística & dados numéricos , População Branca/estatística & dados numéricos , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/etnologia , Doença de Alzheimer/patologia , Feminino , Florida , Humanos , Estudos RetrospectivosRESUMO
Women reportedly make up two-thirds of Alzheimer's disease (AD) dementia sufferers. Many estimates regarding AD, however, are based on clinical series lacking autopsy confirmation. The Florida Autopsied Multi-Ethnic (FLAME) cohort was queried for AD cases with a total of 1625 identified ranging in age from 53 to 102 years at death. Standard neuropathologic procedures were employed and clinical information was retrospectively collected. Clinicopathologic and genetic data (MAPT and APOE) were stratified by sex. Within the neuropathologically diagnosed AD cohort, the overall number of women and men did not differ. Men were younger at onset of cognitive symptoms, had a shorter disease duration, and more often had atypical (non-amnestic) clinical presentations. The frequency of autopsy-confirmed AD among women and men stratified by age at death revealed an inverse U-shaped curve in men and a U-shaped curve in women, with both curves having inflections at approximately 70 years of age. Regional counts of neurofibrillary tangles differed in women and men, especially when examined by age intervals. Women had overall greater severity of neurofibrillary tangle counts compared to men, especially in the hippocampus. Men were more often classified as hippocampal sparing AD, whereas limbic predominant AD was more common in women. Men and women did not differ in frequency of MAPT haplotype or APOE genotype. Atypical clinical presentations, younger age at onset and shorter disease duration were more frequent in men, suggesting that the lower reported frequency of AD in men may be due to more frequent atypical clinical presentations not recognized as AD. Our data suggest that neuropathologically diagnosed AD cases have the same frequency of women and men, but their clinical presentations and ages at onset tend to differ.
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Envelhecimento/patologia , Doença de Alzheimer/patologia , Encéfalo/patologia , Caracteres Sexuais , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Autopsia , Encéfalo/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Emaranhados Neurofibrilares/patologia , Escalas de Graduação Psiquiátrica , Estatísticas não ParamétricasRESUMO
Importance: Corticolimbic patterns of neurofibrillary tangle (NFT) accumulation define neuropathologic subtypes of Alzheimer disease (AD), which underlie the clinical heterogeneity observed antemortem. The cholinergic system, which is the target of acetylcholinesterase inhibitor therapy, is selectively vulnerable in AD. Objective: To investigate the major source of cholinergic innervation, the nucleus basalis of Meynert (nbM), in order to determine whether there is differential involvement of NFT accumulation or neuronal loss among AD subtypes. Design, Setting, and Participants: In this cross-sectional study, retrospective abstraction of clinical records and quantitative assessment of NFTs and neuron counts in the nbM was completed in January 2019 at the Mayo Clinic using the Florida Autopsied Multi-Ethnic (FLAME) cohort, which had been accessioned from 1991 until 2015. The FLAME cohort is derived from the deeded autopsy program funded throughout the State of Florida's memory disorder clinic referral services. Of the 2809 consecutively accessioned FLAME cohort, 1464 were identified as neuropathologically diagnosed AD cases and nondemented normal controls available for clinicopathologic assessment. Quantification of NFTs and neuronal density in the anterior nbM was performed blinded to neuropathologic groupings. Main Outcomes and Measures: Demographic and clinical characteristics, including cognitive decline measured using the Mini-Mental State Examination score (range, 0-30), were evaluated. The anterior nbM was investigated quantitatively for neuronal loss and NFT accumulation. Results: In total, 1361 AD subtypes and 103 nondemented controls were assessed. The median (interquartile range) age at death was 72 (66-80) years in hippocampal sparing (HpSp) AD, 81 (76-86) years in typical AD, and 86 (82-90) years in limbic predominant AD. The median (interquartile range) count per 0.125 mm2 of thioflavin S-positive NFTs was highest in the nbM of HpSp AD (14 [9-20]; n = 163), lower in typical AD (10 [5-16]; n = 937), and lowest in limbic predominant AD (8 [5-11], n = 163) (P < .001). The median (interquartile range) neuronal density per millimeters squared was lowest in HpSp AD cases (22 [17-28]; n = 148), higher in typical AD (25 [19-30]; n = 727), and highest in limbic predominant AD (26 [19-32]; n = 127) (P = .002). Multivariable regression modeling of clinical and demographic variables was performed to assess overlap in NFT accumulation and neuronal density differences among AD subtypes. Higher NFT accumulation in the nbM was associated with younger age at onset for HpSp AD (ß, -1.5; 95% CI, -2.9 to -0.15; P = .03) and typical AD (ß, -3.2; 95% CI, -3.9 to -2.4; P < .001). In addition, higher NFT accumulation in the nbM of typical AD cases was associated with female sex (ß, 2.5; 95% CI, 1.4-3.5; P < .001), apolipoprotein E ε4 allele (ß, 1.3; 95% CI, 0.15-2.5; P = .03), and lower Mini-Mental State Examination scores (ß, -1.8; 95% CI, -3.2 to -0.31; P = .02). Demographic and clinical progression variables were not associated with NFT accumulation in the nbM of limbic predominant AD cases. Conclusions and Relevance: These data provide supportive evidence that NFT accumulation in the nbM may underlie more widespread and severe cholinergic deficits in young-onset AD, in particular in patients with HpSp AD. Moreover, these findings underscore the importance of considering age at onset, sex, and apolipoprotein E genotype when assessing outcomes in AD.
Assuntos
Doença de Alzheimer/patologia , Núcleo Basal de Meynert/patologia , Emaranhados Neurofibrilares/patologia , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neurônios/patologia , Estudos RetrospectivosRESUMO
INTRODUCTION: Excessive daytime sleepiness is a commonly reported clinical feature of dementia with Lewy bodies (DLB) that can occur early in the disease. Cholinergic depletion is known to be severe in DLB, even when dementia severity is mild. The nucleus basalis of Meynert serves as a primary source of cortical acetylcholine, and has a role in facilitating cortical activation and arousal. We sought to determine whether daytime sleepiness at the initial evaluation of patients with DLB was associated with neuronal loss in the nucleus basalis of Meynert. METHODS: Autopsy-confirmed patients who met clinical criteria for probable DLB at their initial evaluation and who were administered the informant-completed Epworth Sleepiness Scale were included in the study (nâ¯=â¯40). Each patient had a dementia at baseline (80% with mild severity) and two or more features of parkinsonism, visual hallucinations, fluctuations, or probable REM sleep behavior disorder. Quantitative digital pathology of the nucleus basalis of Meynert was performed in the DLB group and in 20 non-DLB autopsy controls. RESULTS: DLB had greater neuronal depletion in the nucleus basalis of Meynert (pâ¯<â¯0.0001) than pathologic controls. Sleepiness was present in 58% of the DLB group and those with daytime sleepiness had significantly lower neuron counts in the nucleus basalis of Meynert than their non-sleepy counterparts (pâ¯=â¯0.001). Regression modeling revealed that sleepiness was a stronger predictor of neuronal loss in the nucleus basalis of Meynert than visual hallucinations, fluctuations or dementia severity (pâ¯=â¯0.003). CONCLUSIONS: Excessive daytime sleepiness in early DLB is indicative of a more profound loss of basal forebrain cholinergic integrity.