High occurrence of transportation and logistics occupations among vascular dementia patients: an observational study

Background

Growing evidence suggests a role of occupation in the emergence and manifestation of dementia. Occupations are often defined by complexity level, although working environments and activities differ in several other important ways. We aimed to capture the multi-faceted nature of occupation through its measurement as a qualitative (instead of a quantitative) variable and explored its relationship with different types of dementia.

Methods

We collected occupational information of 2121 dementia patients with various suspected etiologies from the Amsterdam Dementia Cohort (age 67 ± 8, 57% male; MMSE 21 ± 5). Our final sample included individuals with Alzheimer’s disease (AD) dementia (n = 1467), frontotemporal dementia (n = 281), vascular dementia (n = 98), Lewy body disease (n = 174), and progressive supranuclear palsy/corticobasal degeneration (n = 101). Within the AD group, we used neuropsychological data to further characterize patients by clinical phenotypes. All participants were categorized into 1 of 11 occupational classes, across which we evaluated the distribution of dementia (sub)types with χ² analyses. We gained further insight into occupation-dementia relationships through post hoc logistic regressions that included various demographic and health characteristics as explanatory variables.

Results

There were significant differences in the distribution of dementia types across occupation groups (χ² = 85.87, p < .001). Vascular dementia was relatively common in the Transportation/Logistics sector, and higher vascular risk factors partly explained this relationship. AD occurred less in Transportation/Logistics and more in Health Care/Welfare occupations, which related to a higher/lower percentage of males. We found no relationships between occupational classes and clinical phenotypes of AD (χ² = 53.65, n.s.).

Conclusions

Relationships between occupation and dementia seem to exist beyond the complexity level, which offers new opportunities for disease prevention and improvement of occupational health policy.

Novel CSF biomarkers to discriminate FTLD and its pathological subtypes

Objective

Frontotemporal lobar degeneration (FTLD) is the second most prevalent dementia in young patients and is characterized by the presence of two main protein aggregates in the brain, tau (FTLD‐Tau) or TDP43 (FTLD‐TDP), which likely require distinct pharmacological therapy. However, specific diagnosis of FTLD and its subtypes remains challenging due to largely overlapping clinical phenotypes. Here, we aimed to assess the clinical performance of novel cerebrospinal fluid (CSF) biomarkers for discrimination of FTLD and its pathological subtypes.

Methods

YKL40, FABP4, MFG‐E8, and the activities of catalase and specific lysosomal enzymes were analyzed in patients with FTLD‐TDP (n = 30), FTLD‐Tau (n = 20), AD (n = 30), DLB (n = 29), and nondemented controls (n = 29) obtained from two different centers. Models were validated in an independent CSF cohort (n = 188).

Results

YKL40 and catalase activity were increased in FTLD‐TDP cases compared to controls. YKL40 levels were also higher in FTLD‐TDP compared to FTLD‐Tau. We identified biomarker models able to discriminate FTLD from nondemented controls (MFG‐E8, tTau, and Aβ₄₂; 78% sensitivity and 83% specificity) and non‐FTLD dementia (YKL40, pTau, p/tTau ratio, and age; 90% sensitivity, 78% specificity), which were validated in an independent cohort. In addition, we identified a biomarker model differentiating FTLD‐TDP from FTLD‐Tau (YKL40, MFGE‐8, βHexA together with βHexA/tHex and p/tTau ratios and age) with 80% sensitivity and 82% specificity.

Interpretation

This study identifies CSF protein signatures distinguishing FTLD and the two main pathological subtypes with optimal accuracy (specificity/sensitivity > 80%). Validation of these models may allow appropriate selection of cases for clinical trials targeting the accumulation of Tau or TDP43, thereby increasing their efficiency and facilitating the development of successful therapies.

Neurofilament light chain: a biomarker for genetic frontotemporal dementia

Objective

To evaluate cerebrospinal fluid (CSF) and serum neurofilament light chain (NfL) levels in genetic frontotemporal dementia (FTD) as a potential biomarker in the presymptomatic stage and during the conversion into the symptomatic stage. Additionally, to correlate NfL levels to clinical and neuroimaging parameters.

Methods

In this multicenter case–control study, we investigated CSF NfL in 174 subjects (48 controls, 40 presymptomatic carriers and 86 patients with microtubule‐associated protein tau (MAPT), progranulin (GRN), and chromosome 9 open reading frame 72 (C9orf72) mutations), and serum NfL in 118 subjects (39 controls, 44 presymptomatic carriers, 35 patients). In 55 subjects both CSF and serum was determined. In two subjects CSF was available before and after symptom onset (converters). Additionally, NfL levels were correlated with clinical parameters, survival, and regional brain atrophy.

Results

CSF NfL levels in patients (median 6762 pg/mL, interquartile range 3186–9309 pg/mL) were strongly elevated compared with presymptomatic carriers (804 pg/mL, 627–1173 pg/mL, P < 0.001), resulting in a good diagnostic performance to discriminate both groups. Serum NfL correlated highly with CSF NfL (r_s= 0.87, P < 0.001) and was similarly elevated in patients. Longitudinal samples in the converters showed a three‐ to fourfold increase in CSF NfL after disease onset. Additionally, NfL levels in patients correlated with disease severity, brain atrophy, annualized brain atrophy rate and survival.

Interpretation

NfL in both serum and CSF has the potential to serve as a biomarker for clinical disease onset and has a prognostic value in genetic FTD.

Genetic risk factors for the posterior cortical atrophy variant of Alzheimer's disease

Introduction

The genetics underlying posterior cortical atrophy (PCA), typically a rare variant of Alzheimer's disease (AD), remain uncertain.

Methods

We genotyped 302 PCA patients from 11 centers, calculated risk at 24 loci for AD/DLB and performed an exploratory genome-wide association study.

Results

We confirm that variation in/near APOE/TOMM40 (P = 6 × 10⁻¹⁴) alters PCA risk, but with smaller effect than for typical AD (PCA: odds ratio [OR] = 2.03, typical AD: OR = 2.83, P = .0007). We found evidence for risk in/near CR1 (P = 7 × 10⁻⁴), ABCA7 (P = .02) and BIN1 (P = .04). ORs at variants near INPP5D and NME8 did not overlap between PCA and typical AD. Exploratory genome-wide association studies confirmed APOE and identified three novel loci: rs76854344 near CNTNAP5 (P = 8 × 10⁻¹⁰ OR = 1.9 [1.5–2.3]); rs72907046 near FAM46A (P = 1 × 10⁻⁹ OR = 3.2 [2.1–4.9]); and rs2525776 near SEMA3C (P = 1 × 10⁻⁸, OR = 3.3 [2.1–5.1]).

Discussion

We provide evidence for genetic risk factors specifically related to PCA. We identify three candidate loci that, if replicated, may provide insights into selective vulnerability and phenotypic diversity in AD.

Atrophy patterns in early clinical stages across distinct phenotypes of Alzheimer's disease

Alzheimer's disease (AD) can present with distinct clinical variants. Identifying the earliest neurodegenerative changes associated with each variant has implications for early diagnosis, and for understanding the mechanisms that underlie regional vulnerability and disease progression in AD. We performed voxel-based morphometry to detect atrophy patterns in early clinical stages of four AD phenotypes: Posterior cortical atrophy (PCA, "visual variant," n=93), logopenic variant primary progressive aphasia (lvPPA, "language variant," n=74), and memory-predominant AD categorized as early age-of-onset (EOAD, <65 years, n=114) and late age-of-onset (LOAD, >65 years, n=114). Patients with each syndrome were stratified based on: (1) degree of functional impairment, as measured by the clinical dementia rating (CDR) scale, and (2) overall extent of brain atrophy, as measured by a neuroimaging approach that sums the number of brain voxels showing significantly lower gray matter volume than cognitively normal controls (n=80). Even at the earliest clinical stage (CDR=0.5 or bottom quartile of overall atrophy), patients with each syndrome showed both common and variant-specific atrophy. Common atrophy across variants was found in temporoparietal regions that comprise the posterior default mode network (DMN). Early syndrome-specific atrophy mirrored functional brain networks underlying functions that are uniquely affected in each variant: Language network in lvPPA, posterior cingulate cortex-hippocampal circuit in amnestic EOAD and LOAD, and visual networks in PCA. At more advanced stages, atrophy patterns largely converged across AD variants. These findings support a model in which neurodegeneration selectively targets both the DMN and syndrome-specific vulnerable networks at the earliest clinical stages of AD.

Unmet needs and health-related quality of life in young-onset dementia

OBJECTIVES

Young-onset dementia (YOD) causes specific challenges and issues that are likely to affect health-related quality of life (HRQOL). This study explored patient and caregiver HRQOL and its association with unmet needs in YOD.

METHODS

A cross-sectional design was used to study 215 community-dwelling YOD patients and their primary caregivers. Multiple linear regression analyses were performed to determine the relationship between unmet needs assessed with the Camberwell Assessment of Need for the Elderly scale and patient and caregiver HRQOL, controlling for other variables such as demographic characteristics, patient functional status, neuropsychiatric symptoms, and caregiver sense of competence.

RESULTS

Patient HRQOL was not associated with unmet needs. However, we found that the unmet needs of both patient and caregiver were related to several domains of caregiver HRQOL.

CONCLUSIONS

This study shows that patient and caregiver unmet needs are related to caregiver HRQOL in YOD. However, the relationship between HRQOL and unmet needs is complex. The assessment of unmet needs within the context of HRQOL seems to be an important prerequisite for personalizing care in YOD. Adjusting supportive services to match the individual needs and preferences of these young patients and their caregivers is likely to enhance their quality of life.

[Amyloid-plaque imaging of the brain using PET]

Alzheimer's disease (AD) is neuropathologically characterized by the presence of senile plaques. The formation of these plaques is caused by the accumulation of amyloid-beta protein (Aβ), a process that begins decades before the onset of the first clinical symptoms. Senile plaques can be visualized by using positron emission tomography (PET) and the tracer 11C-PIB. Such 'amyloid imaging' can contribute significantly to both early and differential diagnosis of Alzheimer's disease. In the future, amyloid imaging could also be useful for selecting patients for clinical trials and in evaluating the effects of disease modifying agents tailored at lowering Aβ burden.