Correlation between instrumental activities of daily living and white matter hyperintensities in amnestic mild cognitive impairment: results of a cross-sectional study

Cross-sectional and prognostic associations of baseline [18F]GTP1 tau PET signal and white matter lesion volumes for cognitive and functional decline in prodromal-to-mild Alzheimer's disease

BACKGROUND

In Alzheimer's disease (AD), tau and white matter lesion pathology are associated with clinical severity and subsequent decline, but their relative relationships with clinical assessments remain uncertain.

OBJECTIVE

To examine cross-sectional and prognostic associations between baseline [18F]GTP1 tau positron emission tomography (PET) standardized uptake value ratio (SUVRs) and T1 white matter hypointensity (WMHypo) volumes with clinical indices.

METHODS

We analyzed participants with biomarker-confirmed prodromal (n = 127) or mild (n = 233) AD with baseline [18F]GTP1 tau PET and MRI and longitudinal Clinical Dementia Rating-Sum of Boxes (CDR-SB), 13-item version of the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog13), Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), Mini-Mental Status Examination (MMSE), and Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL) data.

RESULTS

Higher baseline [18F]GTP1 SUVRs were independently associated with poorer baseline performance and faster rates of subsequent decline on all five clinical outcome measures. Higher baseline WMHypo volumes were independently associated with poorer baseline performance on the CDR-SB, ADAS-Cog13, RBANS, and MMSE and faster rates of subsequent decline on the CDR-SB and ADCS-ADL.

CONCLUSIONS

The independent associations of tau and white matter lesion pathology with clinical decline in AD suggest future prognostic models should include both imaging modalities.

Association between frequency of going out and mild cognitive impairment in community-dwelling older adults: a pilot study in frailty prevention groups

BACKGROUND

Clarifying the role of physical limitations in the relationship between frequency of going out and mild cognitive impairment (MCI) may be useful in supporting early detection and prevention of MCI. However, few studies have explored relatively active populations that are continuously active throughout the year. This study aimed to determine the relationship between frequency of going out and MCI among non-homebound older adults who participated in group activities to prevent frailty.

METHODS

This prospective cohort study used frequency of going out as the exposure and MCI as the outcome. The Touch Panel-type Dementia Assessment Scale and questionnaires about daily life were completed by 153 community-dwelling older adults aged ≥65 years participating in frailty prevention groups in a rural town. The baseline survey was conducted from December 2017 to March 2018 and analysed cross-sectionally. Follow-up surveys were conducted at 1- and 2-years and analysed longitudinally.

RESULTS

Univariate and binomial logistic regression analyses at baseline showed no association between MCI and frequency of going out in older adults with physical limitations. However, there was a significant association in older adults without physical limitations. A binomial logistic regression analysis of the frequency of going out at baseline and cognitive function at the 2-year follow-up showed no association between MCI and frequency of going out in older adults with physical limitations, but there was a significant association in those without physical limitations.

CONCLUSION

Our results suggest that frequency of going out may not be a useful indicator of MCI in older adults with physical limitations, although low frequency of going out may be an indicator of MCI in older adults without physical limitations.

Impact of frontal white matter hyperintensity on instrumental activities of daily living in elderly women with Alzheimer disease and amnestic mild cognitive impairment

Background

Instrumental activities of daily living (IADL) start to decline during the progression of amnestic mild cognitive impairment (aMCI) to Alzheimer disease (AD). Cognitive and physical decline are involved in the loss of functional independence. However, little is known about AD-related neural change that leads to IADL impairment. The purpose of this study was to clarify the effects of regional white matter hyperintensity (WMH) on IADL impairment in persons with AD and aMCI.

Methods

The participants were 347 female subjects aged 65–85 years diagnosed with AD (n = 227), aMCI (n = 44) or normal cognition (n = 76). IADL was assessed by the Lawton Index. Cognition, mood and mobility function were evaluated by comprehensive geriatric assessment batteries. WMH and brain atrophy were analyzed with brain magnetic resonance imaging, using an automatic segmentation program. Regional WMH was measured in the frontal, temporal, occipital and parietal lobes.

Results

Ability to carry out IADL of shopping, food preparation, mode of transportation, responsibility for own medication, and ability to handle finances was obviously impaired in the early stage of AD. Frontal WMH was specifically associated with disability to do shopping and food preparation even after adjusting for several confounders including brain atrophy.

Conclusions

IADL subcategories were differentially impaired along with cognitive status in persons with AD and aMCI. Frontal WMH was an important predictor of impaired ability to do shopping and food preparation. A preventive strategy for WMH might lead to suppression of IADL disability and slow the progression of AD.

White matter hyperintensities and geriatric syndrome: An important role of arterial stiffness

White matter hyperintensities (WMH) are defined as cerebral white matter changes presumed to be of vascular origin, bilateral and mostly symmetrical. They can appear as hyperintense on T2-weighted and fluid-attenuated inversion recovery sequences, and as isointense or hypointense on T1-weighted magnetic resonance imaging of the brain. WMH have been focused on because of their clinical importance as a risk factor for cerebrovascular diseases and cognitive impairment. WMH are associated with geriatric syndrome, which is defined by clinical symptoms characteristic of older adults, including cognitive and functional impairment and falls. Cerebral small vessel diseases, such as WMH, might play an important role as risk factors for cerebrovascular diseases, cognitive impairment and geriatric syndrome through the mechanism of arterial stiffness. However, the vascular, physiological and metabolic roles of arterial stiffness remain unclear. Basically, arterial stiffness indicates microvessel arteriosclerosis presenting with vascular endothelial dysfunction. These changes might arise from hemodynamic stress as a result of a "tsunami effect" on cerebral parenchyma. In the present article, we review the clinical characteristics of WMH, focusing particularly on two associations: (i) those between cerebral small vessel diseases including WMH and arterial stiffness; and (ii) those between WMH and geriatric syndrome.

The Combined Effect of Neuropsychological and Neuropathological Deficits on Instrumental Activities of Daily Living in Older Adults: a Systematic Review

To date, studies have consistently demonstrated associations between either neuropsychological deficits or neuroanatomical changes and instrumental activities of daily living (IADL) in aging. Only a limited number of studies have evaluated morphological brain changes and neuropsychological test performance concurrently in relation to IADL in this population. As a result, it remains largely unknown whether these factors independently predict functional outcome. The current systematic review intended to address this lack of information by reviewing the literature on older adults, incorporating studies that examined e.g., normal aging, but also stroke or dementia patients. A comprehensive search of databases (Pubmed, Embase, Medline, Web of Science, PsycINFO) and reference lists was performed, focusing on papers in the English language that examined the combined effect of neuropsychological and neuroanatomical factors on IADL in samples of adults with an average age above 50. In total, 58 potential articles were identified; 20 were included in the review. The results show that especially neuropsychological variables (primarily memory and executive functions) independently predict IADL. Although some unique predictive value of brain morphological changes, such as hippocampal atrophy, was found, support for the importance of white matter changes was limited. However, the results of the studies reviewed are diverse, and appear to be at least partially determined by the variables included. For example, studies were less likely to find an independent effect of cognition if they solely employed a cognitive screening instrument. This indicates that a structured examination of neuroanatomical and neuropsychological correlates of IADL in different patient populations is warranted.