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In 2020, the Lancet Commission identified 12 modifiable factors that increase population-level dementia risk. It is unclear if these risk factors co-occur among individuals in a clinically meaningful way. Using latent class analysis, we identified profiles of modifiable dementia risk factors in dementia-free adults aged 60-64 years from the UK Biobank. We then estimated associations between these profiles with incident dementia, cognition, and neuroimaging outcomes, and explored the differences across profiles in the effects of a polygenic risk score for Alzheimer's disease on outcomes. In 55,333 males and 63,063 females, three sex-specific latent profiles were identified: cardiometabolic risk, substance use-related risk, and low risk. The cardiometabolic risk profile in both males and females was associated with greater incidence of all-cause dementia (male: OR [95% CI] = 2.33 [2.03, 2.66]; female: OR [95% CI] = 1.44 [1.24, 1.68]), poorer cognitive performance, greater brain atrophy, and greater white matter hyperintensity volume compared to the low risk profile. The substance use-related risk profile in males was associated with poorer cognitive performance and greater white matter hyperintensities compared to the low risk profile, but no difference in all-cause dementia incidence was observed (OR [95% CI] = 1.00 [0.95, 1.06]). In females, the substance use-related risk profile demonstrated increased dementia incidence (OR [95% CI] = 1.58 [1.57, 1.58]) and greater brain atrophy but smaller white matter hyperintensity volume compared to the low risk profile. The polygenic risk score had larger effects among females, and differentially influenced outcomes across profiles; for instance, there were larger effects of the polygenic risk score on atrophy in the cardiometabolic profile vs. the low risk profile among males, and larger effects of the polygenic risk score on loss of white matter integrity in the cardiometabolic profile vs. the low risk profile among females. These results reveal three modifiable dementia risk profiles, their unique cognitive/neuroimaging outcomes, and their interactions with genetic risk for Alzheimer's disease. These differences highlight the need to consider population heterogeneity in risk prediction tools and in planning personalized prevention strategies.
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Greater sage-grouse (Centrocercus urophasianus) are a critically endangered species in Canada with fewer than 140 individuals remaining on native habitats in southern Alberta and Saskatchewan. In 2014, the Wilder Institute/Calgary Zoo initiated North America's only zoo-based conservation breeding program for this species to bolster declining wild populations through conservation reintroductions. Within the managed population of sage-grouse, morbidity and mortality have primarily been associated with intestinal bacterial infections. As a preliminary study to assess the gastrointestinal health of this species in managed care, the fecal bacterial microbiome of adult and juvenile captive sage-grouse was characterized with 16S rRNA sequencing. The composition of the microbiome at the phylum level in greater sage-grouse is consistent with previous studies of the avian microbiome, with Bacillota as the most abundant phyla, and Actinomycetota, Bacteroidota and Pseudomonadota also being highly abundant. Antibiotic use and sex did not have a significant impact on the diversity or composition of the microbiome, but the management of juvenile sage-grouse did influence the development of the microbiome. Juveniles that were raised outdoors under maternal care developed a microbiome much more similar to adults when compared to chicks that were incubated and hand-raised. The local environment and parental care appear to be important factors influencing the diversity and composition of the gastrointestinal microbiome in this species.
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AIMS: This study examined serum cytochrome P450-soluble epoxide hydrolase (CYP450-sEH) oxylipins and depressive symptoms together in relation to cognitive performance in individuals with type 2 diabetes mellitus (T2DM). METHODS: Clinically cognitively normal T2DM individuals were recruited (NCT04455867). Depressive symptom severity was assessed using the Beck Depression Inventory-II (BDI-II; total scores ≤13 indicated minimal depressive symptoms and ≥ 14 indicated significant depressive symptoms). Executive function and verbal memory were assessed. Fasting serum oxylipins were quantified by ultra-high-performance liquid chromatography tandem mass-spectrometry. RESULTS: The study included 85 participants with minimal depressive symptoms and 27 with significant symptoms (mean age: 63.3 ± 9.8 years, 49 % women). In all participants, higher concentrations of linoleic acid derived sEH (12,13-dihydroxyoctadecamonoenoic acid; DiHOME) and CYP450 (12(13)-epoxyoctadecamonoenoic acid; EpOME) metabolites were associated with poorer executive function (F1,101 = 6.094, p = 0.015 and F1,101 = 5.598, p = 0.020, respectively). Concentrations of multiple sEH substrates interacted with depressive symptoms to predict 1) poorer executive function, including 9(10)-EpOME (F1,100 = 12.137, p < 0.001), 5(6)-epoxyeicosatrienoic acid (5(6)-EpETrE; F1,100 = 6.481, p = 0.012) and 11(12)-EpETrE (F1,100 = 4.409, p = 0.038), and 2) verbal memory, including 9(10)-EpOME (F1,100 = 4.286, p = 0.041), 5(6)-EpETrE (F1,100 = 6.845, p = 0.010), 11(12)-EpETrE (F1,100 = 3.981, p = 0.049) and 14(15)-EpETrE (F1,100 = 5.019, p = 0.027). CONCLUSIONS: Associations of CYP450-sEH metabolites and depressive symptoms with cognition highlight the biomarker and therapeutic potential of the CYP450-sEH pathway in T2DM.
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Sistema Enzimático do Citocromo P-450 , Depressão , Diabetes Mellitus Tipo 2 , Epóxido Hidrolases , Oxilipinas , Humanos , Epóxido Hidrolases/metabolismo , Epóxido Hidrolases/sangue , Feminino , Pessoa de Meia-Idade , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/psicologia , Masculino , Oxilipinas/sangue , Sistema Enzimático do Citocromo P-450/metabolismo , Idoso , Depressão/sangue , Depressão/diagnóstico , Cognição/fisiologia , Disfunção Cognitiva/sangue , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/diagnóstico , Função Executiva/fisiologia , Estudos TransversaisRESUMO
INTRODUCTION: We investigated the effect of perivascular spaces (PVS) volume on speeded executive function (sEF), as mediated by white matter hyperintensities (WMH) volume and plasma glial fibrillary acidic protein (GFAP) in neurodegenerative diseases. METHODS: A mediation analysis was performed to assess the relationship between neuroimaging markers and plasma biomarkers on sEF in 333 participants clinically diagnosed with Alzheimer's disease/mild cognitive impairment, frontotemporal dementia, or cerebrovascular disease from the Ontario Neurodegenerative Disease Research Initiative. RESULTS: PVS was significantly associated with sEF (c = -0.125 ± 0.054, 95% bootstrap confidence interval [CI] [-0.2309, -0.0189], p = 0.021). This effect was mediated by both GFAP and WMH. DISCUSSION: In this unique clinical cohort of neurodegenerative diseases, we demonstrated that the effect of PVS on sEF was mediated by the presence of elevated plasma GFAP and white matter disease. These findings highlight the potential utility of imaging and plasma biomarkers in the current landscape of therapeutics targeting dementia. HIGHLIGHTS: Perivascular spaces (PVS) and white matter hyperintensities (WMH) are imaging markers of small vessel disease. Plasma glial fibrillary protein acidic protein (GFAP) is a biomarker of astroglial injury. PVS, WMH, and GFAP are relevant in executive dysfunction from neurodegeneration. PVS's effect on executive function was mediated by GFAP and white matter disease.
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PURPOSE: This study examines the diagnostic accuracy of brain perfusion SPECT for mild traumatic brain injury (mTBI). PATIENTS AND METHODS: A systematic review and meta-analysis was performed according to PRISMA guidelines (PROSPERO: CRD42023484636). Five databases were searched for studies evaluating brain perfusion SPECT in adult patients with mTBI (GCS 13-15). Study quality was assessed using a modified QUADAS-2 tool. A meta-analysis was performed to pool proportions of hypoperfusion abnormalities across brain lobes. RESULTS: Of 4735 records, 22 studies (5 longitudinal [40% high quality], 17 cross-sectional [24% high quality]) were included totaling 800 patients (mean age, 37.4 ± 12.6 years; 36.4% female). Meta-analysis of proportions indicated that the frontal lobe most frequently showed hypoperfusion on brain perfusion SPECT (pooled proportion 40.1% [95% confidence interval, 31.2% to 49.8%], 99/254, I2 = 54.5%), followed by the temporal lobe (26.1% [95% confidence interval, 19.9% to 33.6%], 68/254, I2 = 30.7%). Several studies found that hypoperfusion abnormalities were associated with neuropsychological findings. Also, brain perfusion SPECT could detect abnormalities not seen on MRI. Abnormalities in perfusion on brain perfusion SPECT may be more readily detected with a quantitative assessment compared with a visual assessment alone, although there appears to be no consensus on the optimal method for image interpretation. Evidence evaluating the sensitivity and specificity of brain perfusion SPECT for mTBI was limited. Using the GRADE framework, the evidence was rated as low. CONCLUSIONS: Although perfusion abnormalities can be seen in patients with mTBI, commonly in the frontal and temporal lobes, the findings are nonspecific and may derive from various factors. Ultimately, brain perfusion SPECT provides additional information for mTBI, but the final added value for the detection of mTBI is unknown.
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Alzheimer's disease (AD) is a brain network disorder where pathological proteins accumulate through networks and drive cognitive decline. Yet, the role of network connectivity in facilitating this accumulation remains unclear. Using in-vivo multimodal imaging, we show that the distribution of tau and reactive microglia in humans follows spatial patterns of connectivity variation, the so-called gradients of brain organization. Notably, less distinct connectivity patterns ("gradient contraction") are associated with cognitive decline in regions with greater tau, suggesting an interaction between reduced network differentiation and tau on cognition. Furthermore, by modeling tau in subject-specific gradient space, we demonstrate that tau accumulation in the frontoparietal and temporo-occipital cortices is associated with greater baseline tau within their functionally and structurally connected hubs, respectively. Our work unveils a role for both functional and structural brain organization in pathology accumulation in AD, and supports subject-specific gradient space as a promising tool to map disease progression.
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Doença de Alzheimer , Encéfalo , Imageamento por Ressonância Magnética , Proteínas tau , Humanos , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Doença de Alzheimer/diagnóstico por imagem , Proteínas tau/metabolismo , Masculino , Feminino , Idoso , Encéfalo/metabolismo , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Microglia/metabolismo , Microglia/patologia , Idoso de 80 Anos ou mais , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/patologia , Disfunção Cognitiva/diagnóstico por imagem , Pessoa de Meia-Idade , Rede Nervosa/metabolismo , Rede Nervosa/patologia , Rede Nervosa/diagnóstico por imagem , Mapeamento Encefálico/métodosRESUMO
Post-acute COVID syndrome (PACS) is a global health concern and is often associated with debilitating symptoms. Post-COVID fatigue is a particularly frequent and troubling issue, and its underlying mechanisms remain incompletely understood. One potential contributor is micropathological injury of subcortical and brainstem structures, as has been identified in other patient populations. Texture-based analysis (TA) may be used to measure such changes in anatomical MRI data. The present study develops a methodology of voxel-wise TA mapping in subcortical and brainstem regions, which is then applied to T1-weighted MRI data from a cohort of 48 individuals who had PACS (32 with and 16 without ongoing fatigue symptoms) and 15 controls who had cold and flu-like symptoms but tested negative for COVID-19. Both groups were assessed an average of 4-5 months post-infection. There were no significant differences between PACS and control groups, but significant differences were observed within the PACS groups, between those with and without fatigue symptoms. This included reduced texture energy and increased entropy, along with reduced texture correlation, cluster shade and profile in the putamen, pallidum, thalamus and brainstem. These findings provide new insights into the neurophysiological mechanisms that underlie PACS, with altered tissue texture as a potential biomarker of this debilitating condition.
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Tronco Encefálico , COVID-19 , Fadiga , Imageamento por Ressonância Magnética , Síndrome de COVID-19 Pós-Aguda , Humanos , COVID-19/complicações , COVID-19/diagnóstico por imagem , Masculino , Feminino , Fadiga/diagnóstico por imagem , Fadiga/etiologia , Fadiga/patologia , Pessoa de Meia-Idade , Adulto , Tronco Encefálico/diagnóstico por imagem , Tronco Encefálico/patologia , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Tálamo/diagnóstico por imagem , Tálamo/patologia , Idoso , Putamen/diagnóstico por imagem , Putamen/patologia , SARS-CoV-2RESUMO
BACKGROUND AND OBJECTIVES: Mounting evidence supports sex differences in Alzheimer disease (AD) risk. Vascular and hormonal factors may together contribute to AD risk in female adults. We investigated whether age at menopause, vascular risk, and history of hormone therapy (HT) containing estrogens together influence cognition over a 3-year follow-up period. We hypothesized that earlier menopause and elevated vascular risk would have a synergistic association with lower cognitive scores at follow-up and that HT containing estrogens would attenuate this synergistic association to preserve cognition. METHODS: We used data from postmenopausal female participants and age-matched male participants in the Canadian Longitudinal Study on Aging. Vascular risk was calculated using a summary score of elevated blood pressure, antihypertensive medications, elevated low-density lipoprotein cholesterol, diabetes, smoking, and obesity. Cognition was measured with a global cognitive composite at baseline and 3-year follow-up. Linear models tested independent and interactive associations of age at menopause, vascular risk, and HT history with cognition at 3-year follow-up, adjusting for baseline cognition, baseline age, years of education, and test language (English/French). RESULTS: We included 8,360 postmenopausal female participants (mean age at baseline = 65.0 ± 8.53 years, mean age at menopause = 50.1 ± 4.62 years) and 8,360 age-matched male participants for comparison. There was an interaction between age at menopause and vascular risk, such that earlier menopause and higher vascular risk were synergistically associated with lower cognitive scores at follow-up (ß = 0.013, 95% CI 0.001-0.025, p = 0.03). In stratified analyses, vascular risk was associated with lower cognitive scores in female participants with earlier menopause (menopausal ages 35-48 years; ß = -0.044, 95% CI -0.066 to -0.022, p < 0.001), but not average (ages 49-52 years; ß = -0.007, 95% CI -0.027 to 0.012, p = 0.46) or later menopause (ages 53-65 years; ß = 0.003, 95% CI -0.020 to 0.025, p = 0.82). The negative association of vascular risk with cognition in female participants with earlier menopause was stronger than the equivalent association in age-matched male participants. HT history did not further modify the synergistic association of age at menopause and vascular risk with follow-up cognition (ß = -0.005, 95% CI -0.032 to 0.021, p = 0.69). DISCUSSION: Endocrine and vascular processes may synergistically contribute to increased risk of cognitive decline in female adults. These findings have implications for the development of sex-specific dementia prevention strategies.
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Doença de Alzheimer , Disfunção Cognitiva , Feminino , Humanos , Masculino , Envelhecimento , Doença de Alzheimer/tratamento farmacológico , Canadá/epidemiologia , Cognição , Disfunção Cognitiva/tratamento farmacológico , Estrogênios/uso terapêutico , Estudos Longitudinais , Menopausa , Pessoa de Meia-Idade , IdosoRESUMO
INTRODUCTION: We conducted a rapid systematic review of minimal clinically important differences (MCIDs) for Alzheimer's disease (AD) trial endpoints. METHODS: Two reviewers searched EMBASE, MEDLINE, and PubMed from inception to June 4, 2023. RESULTS: Ten articles were retrieved. For mild cognitive impairment (MCI), a change of +2 to +3 points on the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog), +1 points on the Clinical Dementia Rating scale sum of boxes (CDR-SB), -5 points on the integrated Alzheimer's Disease Rating Scale (iADRS), or -1 to -2 points on the Mini-Mental State Examination (MMSE) was considered meaningful. For patients with mild AD, a change of +3 on the ADAS-Cog, +2 points on CDR-SB, -9 points on the iADRS, or -2 points on the MMSE was considered meaningful. For patients with moderate to severe AD, a change of +2 points on the CDR-SB or a change of -1.4 to -3 points on the MMSE was considered meaningful. CONCLUSION: This review identified previously published MCIDs for AD trial endpoints. Input from patients and caregivers will be needed to derive more meaningful endpoints and thresholds. HIGHLIGHTS: This systematic rapid review identified thresholds for minimal clinically important differences (MCIDs) for recently used Alzheimer's disease (AD) trial endpoints: Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog), Clinical Dementia Rating scale sum of boxes (CDR-SB), integrated Alzheimer's Disease Rating Scale (iADRS), Mini-Mental State Examination (MMSE). MCIDs were higher for more severe stages of AD. Average treatment effects in recent trials of anti-amyloid disease modifying monoclonal antibodies are lower than previously published MCIDs. In future trials of disease modifying treatments for AD, the proportion of participants in each treatment group that experienced a clinically meaningful decline could be reported. More work is needed to incorporate the values and preferences of patients and care partners in deriving MCIDs.
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Doença de Alzheimer , Disfunção Cognitiva , Diferença Mínima Clinicamente Importante , Doença de Alzheimer/diagnóstico , Humanos , Disfunção Cognitiva/diagnóstico , Testes de Estado Mental e Demência/estatística & dados numéricos , Testes Neuropsicológicos/estatística & dados numéricos , Ensaios Clínicos como AssuntoRESUMO
INTRODUCTION: Cerebral small vessel disease (SVD) and amyloid beta (Aß) pathology frequently co-exist. The impact of concurrent pathology on the pattern of hippocampal atrophy, a key substrate of memory impacted early and extensively in dementia, remains poorly understood. METHODS: In a unique cohort of mixed Alzheimer's disease and moderate-severe SVD, we examined whether total and regional neuroimaging measures of SVD, white matter hyperintensities (WMH), and Aß, as assessed by 18F-AV45 positron emission tomography, exert additive or synergistic effects on hippocampal volume and shape. RESULTS: Frontal WMH, occipital WMH, and Aß were independently associated with smaller hippocampal volume. Frontal WMH had a spatially distinct impact on hippocampal shape relative to Aß. In contrast, hippocampal shape alterations associated with occipital WMH spatially overlapped with Aß-vulnerable subregions. DISCUSSION: Hippocampal degeneration is differentially sensitive to SVD and Aß pathology. The pattern of hippocampal atrophy could serve as a disease-specific biomarker, and thus guide clinical diagnosis and individualized treatment strategies for mixed dementia.
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Doença de Alzheimer , Peptídeos beta-Amiloides , Doenças de Pequenos Vasos Cerebrais , Hipocampo , Tomografia por Emissão de Pósitrons , Humanos , Hipocampo/patologia , Hipocampo/diagnóstico por imagem , Doenças de Pequenos Vasos Cerebrais/patologia , Doenças de Pequenos Vasos Cerebrais/diagnóstico por imagem , Masculino , Idoso , Feminino , Doença de Alzheimer/patologia , Doença de Alzheimer/diagnóstico por imagem , Peptídeos beta-Amiloides/metabolismo , Substância Branca/patologia , Substância Branca/diagnóstico por imagem , Atrofia/patologia , Imageamento por Ressonância Magnética , Idoso de 80 Anos ou mais , Neuroimagem , Estudos de CoortesRESUMO
INTRODUCTION: Effective longitudinal biomarkers that track disease progression are needed to characterize the presymptomatic phase of genetic frontotemporal dementia (FTD). We investigate the utility of cerebral perfusion as one such biomarker in presymptomatic FTD mutation carriers. METHODS: We investigated longitudinal profiles of cerebral perfusion using arterial spin labeling magnetic resonance imaging in 42 C9orf72, 70 GRN, and 31 MAPT presymptomatic carriers and 158 non-carrier controls. Linear mixed effects models assessed perfusion up to 5 years after baseline assessment. RESULTS: Perfusion decline was evident in all three presymptomatic groups in global gray matter. Each group also featured its own regional pattern of hypoperfusion over time, with the left thalamus common to all groups. Frontal lobe regions featured lower perfusion in those who symptomatically converted versus asymptomatic carriers past their expected age of disease onset. DISCUSSION: Cerebral perfusion is a potential biomarker for assessing genetic FTD and its genetic subgroups prior to symptom onset. HIGHLIGHTS: Gray matter perfusion declines in at-risk genetic frontotemporal dementia (FTD). Regional perfusion decline differs between at-risk genetic FTD subgroups . Hypoperfusion in the left thalamus is common across all presymptomatic groups. Converters exhibit greater right frontal hypoperfusion than non-converters past their expected conversion date. Cerebral hypoperfusion is a potential early biomarker of genetic FTD.
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Proteína C9orf72 , Circulação Cerebrovascular , Demência Frontotemporal , Imageamento por Ressonância Magnética , Proteínas tau , Humanos , Demência Frontotemporal/genética , Demência Frontotemporal/fisiopatologia , Demência Frontotemporal/diagnóstico por imagem , Feminino , Masculino , Pessoa de Meia-Idade , Estudos Longitudinais , Circulação Cerebrovascular/fisiologia , Circulação Cerebrovascular/genética , Proteína C9orf72/genética , Proteínas tau/genética , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Progranulinas/genética , Biomarcadores , Progressão da Doença , Encéfalo/diagnóstico por imagem , Heterozigoto , Mutação , Idoso , Marcadores de Spin , AdultoRESUMO
Background: The detection and characterization of speech changes may help in the identification and monitoring of neurodegenerative diseases. However, there is limited research validating the relationship between speech changes and clinical symptoms across a wide range of neurodegenerative diseases. Method: We analyzed speech recordings from 109 patients who were diagnosed with various neurodegenerative diseases, including Alzheimer's disease, Frontotemporal Dementia, and Vascular Cognitive Impairment, in a cognitive neurology memory clinic. Speech recordings of an open-ended picture description task were processed using the Winterlight speech analysis platform which generates >500 speech features, including the acoustics of speech and linguistic properties of spoken language. We investigated the relationship between the speech features and clinical assessments including the Mini Mental State Examination (MMSE), Mattis Dementia Rating Scale (DRS), Western Aphasia Battery (WAB), and Boston Naming Task (BNT) in a heterogeneous patient population. Result: Linguistic features including lexical and syntactic features were significantly correlated with clinical assessments in patients, across diagnoses. Lower MMSE and DRS scores were associated with the use of shorter words and fewer prepositional phrases. Increased impairment on WAB and BNT was correlated with the use of fewer nouns but more pronouns. Patients also differed from healthy adults as their speech duration was significantly shorter with more pauses. Conclusion: Linguistic changes such as the use of simpler vocabularies and syntax were detectable in patients with different neurodegenerative diseases and correlated with cognitive decline. Speech has the potential to be a sensitive measure for detecting cognitive impairments across various neurodegenerative diseases.
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INTRODUCTION: Hypertension and diabetes are common cardiovascular risk factors that increase Alzheimer's disease (AD) risk. However, it is unclear whether AD risk differs in hypertensive individuals with and without diabetes. METHODS: Cognitively normal individuals (N = 11,074) from the National Alzheimer's Coordinating Center (NACC) were categorized as having (1) hypertension with diabetes (HTN+/DM+), (2) hypertension without diabetes (HTN+/DM-), or (3) neither (HTN-/DM-). AD risk in HTN+/DM+ and HTN+/DM- was compared to HTN-/DM-. This risk was then investigated in those with AD neuropathology (ADNP), cerebral amyloid angiopathy (CAA), cerebrovascular neuropathology (CVNP), arteriolosclerosis, and atherosclerosis. Finally, AD risk in HTN-/DM+ was compared to HTN-/DM-. RESULTS: Seven percent (N = 830) of individuals developed AD. HTN+/DM+ (hazard ratio [HR] = 1.31 [1.19-1.44]) and HTN+/DM- (HR = 1.24 [1.17-1.32]) increased AD risk compared to HTN-/DM-. AD risk was greater in HTN+/DM+ with ADNP (HR = 2.10 [1.16-3.79]) and CAA (HR = 1.52 [1.09-2.12]), and in HTN+/DM- with CVNP (HR = 1.54 [1.17-2.03]). HTN-/DM+ also increased AD risk (HR = 1.88 [1.30-2.72]) compared to HTN-/DM-. DISCUSSION: HTN+/DM+ and HTN+/DM- increased AD risk compared to HTN-/DM-, but pathological differences between groups suggest targeted therapies may be warranted based on cardiovascular risk profiles. HIGHLIGHTS: AD risk was studied in hypertensive (HTN+) individuals with/without diabetes (DM+/-). HTN+/DM+ and HTN+/DM- both had an increased risk of AD compared to HTN-/DM-. Post mortem analysis identified neuropathological differences between HTN+/DM+ and HTN+/DM-. In HTN+/DM+, AD risk was greater in those with AD neuropathology and CAA. In HTN+/DM-, AD risk was greater in those with cerebrovascular neuropathology.
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Doença de Alzheimer , Aterosclerose , Angiopatia Amiloide Cerebral , Diabetes Mellitus , Hipertensão , Humanos , Doença de Alzheimer/epidemiologia , Doença de Alzheimer/patologia , Hipertensão/complicações , Hipertensão/epidemiologia , Diabetes Mellitus/epidemiologiaRESUMO
INTRODUCTION: Apolipoprotein E E4 allele (APOE E4) and slow gait are independently associated with cognitive impairment and dementia. However, it is unknown whether their coexistence is associated with poorer cognitive performance and its underlying mechanism in neurodegenerative diseases. METHODS: Gait speed, APOE E4, cognition, and neuroimaging were assessed in 480 older adults with neurodegeneration. Participants were grouped by APOE E4 presence and slow gait. Mediation analyses were conducted to determine if brain structures could explain the link between these factors and cognitive performance. RESULTS: APOE E4 carriers with slow gait had the lowest global cognitive performance and smaller gray matter volumes compared to non-APOE E4 carriers with normal gait. Coexistence of APOE E4 and slow gait best predicted global and domain-specific poorer cognitive performances, mediated by smaller gray matter volume. DISCUSSION: Gait slowness in APOE E4 carriers with neurodegenerative diseases may indicate extensive gray matter changes associated with poor cognition. HIGHLIGHTS: APOE E4 and slow gait are risk factors for cognitive decline in neurodegenerative diseases. Slow gait and smaller gray matter volumes are associated, independently of APOE E4. Worse cognition in APOE E4 carriers with slow gait is explained by smaller GM volume. Gait slowness in APOE E4 carriers indicates poorer cognition-related brain changes.
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Apolipoproteína E4 , Doenças Neurodegenerativas , Humanos , Idoso , Apolipoproteína E4/genética , Doenças Neurodegenerativas/genética , Genótipo , Cognição , Marcha , Apolipoproteínas E/genéticaRESUMO
OBJECTIVES: Neuropsychiatric symptoms (NPS) increase risk of developing dementia and are linked to various neurodegenerative conditions, including mild cognitive impairment (MCI due to Alzheimer's disease [AD]), cerebrovascular disease (CVD), and Parkinson's disease (PD). We explored the structural neural correlates of NPS cross-sectionally and longitudinally across various neurodegenerative diagnoses. METHODS: The study included individuals with MCI due to AD, (n = 74), CVD (n = 143), and PD (n = 137) at baseline, and at 2-years follow-up (MCI due to AD, n = 37, CVD n = 103, and PD n = 84). We assessed the severity of NPS using the Neuropsychiatric Inventory Questionnaire. For brain structure we included cortical thickness and subcortical volume of predefined regions of interest associated with corticolimbic and frontal-executive circuits. RESULTS: Cross-sectional analysis revealed significant negative correlations between appetite with both circuits in the MCI and CVD groups, while apathy was associated with these circuits in both the MCI and PD groups. Longitudinally, changes in apathy scores in the MCI group were negatively linked to the changes of the frontal-executive circuit. In the CVD group, changes in agitation and nighttime behavior were negatively associated with the corticolimbic and frontal-executive circuits, respectively. In the PD group, changes in disinhibition and apathy were positively associated with the corticolimbic and frontal-executive circuits, respectively. CONCLUSIONS: The observed correlations suggest that underlying pathological changes in the brain may contribute to alterations in neural activity associated with MBI. Notably, the difference between cross-sectional and longitudinal results indicates the necessity of conducting longitudinal studies for reproducible findings and drawing robust inferences.
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Doença de Alzheimer , Transtornos Cerebrovasculares , Disfunção Cognitiva , Doença de Parkinson , Humanos , Estudos Transversais , Doença de Parkinson/psicologia , Estudos Longitudinais , Disfunção Cognitiva/psicologia , Doença de Alzheimer/psicologia , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Transtornos Cerebrovasculares/complicações , Testes NeuropsicológicosRESUMO
OBJECTIVE: Carotid artery webs are an underappreciated cause of recurrent ischemic stroke, and may represent a significant portion of cryptogenic stroke. Evidence-based guidelines for the management of symptomatic carotid webs do not exist. The goal of this study is to audit our local experience for patients with symptomatic carotid artery webs undergoing carotid stenting as a treatment option, along with describing the hypothesized dynamic physiology of carotid webs. METHODS: All patients undergoing stenting for symptomatic carotid artery web at two comprehensive regional stroke centers with high endovascular thrombectomy volume from January 1, 2012 to March 1, 2021 were included. The modified Rankin Scale (mRS) score was used to define functional outcome at 3 months after stenting. RESULTS: Fourteen consecutive patients with symptomatic carotid artery webs underwent stenting. Twelve patients were female (86%), with a median age of 54 (IQR, 48-64) years across all patients. Stroke was the qualifying event in 12 (86%) patients and TIA in 2. Eleven patients (11/14, 79%) achieved a mRS score of 0-2 at 90 days, 2 (14%) were mRS 3-5, and one patient was lost to follow-up. The median follow-up was 12 months (IQR, 10-12). There was no recurrent stroke or TIA like symptoms in any patients. CONCLUSIONS: Carotid stenting appears to be safe at preventing recurrent stroke/TIA with a median follow-up of 12 months in this retrospective multicenter observational study.
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BACKGROUND: Within the spectrum of Lewy body disorders (LBD), both Parkinson's disease (PD) and dementia with Lewy bodies (DLB) are characterized by gait and balance disturbances, which become more prominent under dual-task (DT) conditions. The brain substrates underlying DT gait variations, however, remain poorly understood in LBD. OBJECTIVE: To investigate the relationship between gray matter volume loss and DT gait variations in LBD. METHODS: Seventy-nine participants including cognitively unimpaired PD, PD with mild cognitive impairment, PD with dementia (PDD), or DLB and 20 cognitively unimpaired controls were examined across a multi-site study. PDD and DLB were grouped together for analyses. Differences in gait speed between single and DT conditions were quantified by dual task cost (DTC). Cortical, subcortical, ventricle, and cerebellum brain volumes were obtained using FreeSurfer. Linear regression models were used to examine the relationship between gray matter volumes and DTC. RESULTS: Smaller amygdala and total cortical volumes, and larger ventricle volumes were associated with a higher DTC across LBD and cognitively unimpaired controls. No statistically significant interaction between group and brain volumes were found. Adding cognitive and motor covariates or white matter hyperintensity volumes separately to the models did not affect brain volume and DTC associations. CONCLUSION: Gray matter volume loss is associated with worse DT gait performance compared to single task gait, across cognitively unimpaired controls through and the LBD spectrum. Impairment in DT gait performance may be driven by age-related cortical neurodegeneration.
Assuntos
Doença de Alzheimer , Doença por Corpos de Lewy , Doença de Parkinson , Humanos , Envelhecimento , Doença de Alzheimer/complicações , Marcha , Substância Cinzenta/diagnóstico por imagem , Corpos de Lewy , Doença por Corpos de Lewy/diagnóstico por imagem , Doença por Corpos de Lewy/complicações , Doença de Parkinson/complicaçõesRESUMO
Plasma amyloid beta (Aß) and tau are emerging as accessible biomarkers for Alzheimer's disease (AD). However, many assays exist with variable test performances, highlighting the need for a comparative assessment to identify the most valid assays for future use in AD and to apply to other settings in which the same biomarkers may be useful, namely, cerebral amyloid angiopathy (CAA). CAA is a progressive cerebrovascular disease characterized by deposition of Aß40 and Aß42 in cortical and leptomeningeal vessels. Novel immunotherapies for AD can induce amyloid-related imaging abnormalities resembling CAA-related inflammation. Few studies have evaluated plasma biomarkers in CAA. Identifying a CAA signature could facilitate diagnosis, prognosis, and a safer selection of patients with AD for emerging immunotherapies. This review evaluates studies that compare the diagnostic test performance of plasma biomarker techniques in AD and cerebrovascular and plasma biomarker profiles of CAA; it also discusses novel hypotheses and future avenues for plasma biomarker research in CAA.