Association of White Matter Hyperintensity Progression with Cognitive Decline in Patients with Amnestic Mild Cognitive Impairment

Volume and Permeability of White Matter Hyperintensity on Cognition: A DCE Imaging Study of an Older Cohort With and Without Cognitive Impairment

BACKGROUND

The impact of blood-brain barrier (BBB) leakage on white matter hyperintensity (WMH) subtypes (location) and its association with clinical factors and cognition remains unclear.

PURPOSE

To investigate the relationship between WMH volume, permeability, clinical factors, and cognition in older individuals across the cognitive spectrum.

STUDY TYPE

Prospective, cross-sectional.

SUBJECTS

A total of 193 older adults with/without cognitive impairment; 128 females; mean age 70.1 years (standard deviation 6.8).

FIELD STRENGTH/SEQUENCE

3 T, GE Dynamic contrast-enhanced, three-dimensional (3D) Magnetization-prepared rapid gradient-echo (MPRAGE T1WI), 3D fluid-attenuated inversion recovery (FLAIR).

ASSESSMENT

Periventricular WMH (PWMH), deep WMH (DWMH), and normal-appearing white matter (NAWM) were segmented using FMRIB automatic segmentation tool algorithms on 3D FLAIR. Hippocampal volume and cortex volume were segmented on 3D T1WI. BBB permeability (Ktrans) and blood plasma volume (Vp) were determined using the Patlak model. Vascular risk factors and cognition were assessed.

STATISTICAL TESTS

Univariate and multivariate analyses were performed to identify factors associated with WMH permeability. Logistic regression analysis assessed the association between WMH imaging features and cognition, adjusting for age, sex, apolipoprotein E4 status, education, and brain volumes. A P-value <0.05 was considered significant.

RESULTS

PWMH exhibited higher Ktrans (0.598 ± 0.509 × 10-3 minute-1) compared to DWMH (0.496 ± 0.478 × 10-3 minute-1) and NAWM (0.476 ± 0.398 × 10-3 minute-1). Smaller PWMH volume and cardiovascular disease (CVD) history were significantly associated with higher Ktrans in PWMH. In DWMH, higher Ktrans were associated with CVD history and cortical volume. In NAWM, it was linked to CVD history and dyslipidemia. Larger PWMH volume (odds ratio [OR] 1.106, confidence interval [CI]: 1.021-1.197) and smaller hippocampal volume (OR 0.069; CI: 0.019-0.253) were independently linked to worse global cognition after covariate adjustment.

DATA CONCLUSION

Elevated BBB leakage in PWMH was associated with lower PWMH volume and prior CVD history. Notably, PWMH volume, rather than permeability, was correlated with cognitive decline, suggesting that BBB leakage in WMH may be a consequence of CVD rather than indicate disease progression.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 3.

A multimodal machine learning model for predicting dementia conversion in Alzheimer's disease

Alzheimer's disease (AD) accounts for 60-70% of the population with dementia. Mild cognitive impairment (MCI) is a diagnostic entity defined as an intermediate stage between subjective cognitive decline and dementia, and about 10-15% of people annually convert to AD. We aimed to investigate the most robust model and modality combination by combining multi-modality image features based on demographic characteristics in six machine learning models. A total of 196 subjects were enrolled from four hospitals and the Alzheimer's Disease Neuroimaging Initiative dataset. During the four-year follow-up period, 47 (24%) patients progressed from MCI to AD. Volumes of the regions of interest, white matter hyperintensity, and regional Standardized Uptake Value Ratio (SUVR) were analyzed using T1, T2-weighted-Fluid-Attenuated Inversion Recovery (T2-FLAIR) MRIs, and amyloid PET (αPET), along with automatically provided hippocampal occupancy scores (HOC) and Fazekas scales. As a result of testing the robustness of the model, the GBM model was the most stable, and in modality combination, model performance was further improved in the absence of T2-FLAIR image features. Our study predicts the probability of AD conversion in MCI patients, which is expected to be useful information for clinician's early diagnosis and treatment plan design.

White Matter Hyperintensity Trajectories in Patients With Progressive and Stable Mild Cognitive Impairment

BACKGROUND AND OBJECTIVES

White matter hyperintensities (WMH) are pathologic brain changes that are associated with increased age and cognitive decline. However, the association of WMH burden with amyloid positivity and conversion to dementia in people with mild cognitive impairment (MCI) is unclear. The aim of this study was to expand on this research by examining whether change in WMH burden over time differs in amyloid-negative (Aβ-) and amyloid-positive (Aβ+) people with MCI who either remain stable or convert to dementia. To examine this question, we compared regional WMH burden in 4 groups: Aβ+ progressor, Aβ- progressor, Aβ+ stable, and Aβ- stable.

METHODS

Participants with MCI from the Alzheimer Disease Neuroimaging Initiative were included if they had APOE ɛ4 status and if amyloid measures were available to determine amyloid status (i.e., Aβ+, or Aβ-). Participants with a baseline diagnosis of MCI and who had APOE ɛ4 information and amyloid measures were included. An average of 5.7 follow-up time points per participant were included, with a total of 5,054 follow-up time points with a maximum follow-up duration of 13 years. Differences in total and regional WMH burden were examined using linear mixed-effects models.

RESULTS

A total of 820 participants (55-90 years of age) were included in the study (Aβ+ progressor, n = 239; Aβ- progressor, n = 22; Aβ+ stable, n = 343; Aβ- stable, n = 216). People who were Aβ- stable exhibited reduced baseline WMH compared with Aβ+ progressors and people who were Aβ+ stable at all regions of interest (β belongs to 0.20-0.33, CI belongs to 0.03-0.49, p < 0.02), except deep WMH. When examining longitudinal results, compared with people who were Aβ- stable, all groups had steeper accumulation in WMH burden with Aβ+ progressors (β belongs to -0.03 to 0.06, CI belongs to -0.05 to 0.09, p < 0.01) having the largest increase (i.e., largest increase in WMH accumulation over time).

DISCUSSION

These results indicate that WMH accumulation contributes to conversion to dementia in older adults with MCI who are Aβ+ and Aβ-.

Investigating the relationship between sleep disturbances and white matter hyperintensities in older adults on the Alzheimer's disease spectrum

Background

While studies report that sleep disturbance can have negative effects on brain vasculature, its impact on cerebrovascular disease such as white matter hyperintensities (WMHs) in beta-amyloid positive older adults remains unexplored.

Methods

Linear regressions, mixed effects models, and mediation analysis examined the crosssectional and longitudinal associations between sleep disturbance, cognition, and WMH burden, and cognition in normal controls (NCs), mild cognitive impairment (MCI), and Alzheimer's disease (AD) at baseline and longitudinally.

Results

People with AD reported more sleep disturbance than NC and MCI. AD with sleep disturbance had more WMHs than AD without sleep disturbances. Mediation analysis revealed an effect of regional WMH burden on the relationship between sleep disturbance and future cognition.

Conclusion

These results suggest that WMH burden and sleep disturbance increases from aging to AD. Sleep disturbance decreases cognition through increases in WMH burden. Improved sleep could mitigate the impact of WMH accumulation and cognitive decline.

Association between total cerebral small vessel disease score and cognitive function in patients with vascular risk factors

Hypertension is the most important risk factor for cerebral small vessel disease (SVD). In this cross-sectional study, we tested the independent association of cerebral SVD burden with global cognitive function and each cognitive domain in patients with vascular risk factors. The Tokyo Women's Medical University Cerebral Vessel Disease (TWMU CVD) registry is an ongoing prospective, observational registry in which patients with any evidence of CVD in magnetic resonance imaging (MRI) and at least one vascular risk factor were consecutively enrolled. For SVD-related findings, we evaluated white matter hyperintensity, lacunar infarction, cerebral microbleeds, enlarged perivascular space, and medial temporal atrophy. We used the total SVD score as the SVD burden. They underwent the Mini-mental State Examination (MMSE) and Japanese version of the Montreal Cognitive Assessment (MoCA-J) global cognitive tests, and each cognitive domain was evaluated. After excluding patients without MRI T2* images and those with MMSE score <24, we analyzed 648 patients. The total SVD score was significantly associated with MMSE and MoCA-J scores. After adjustment for age, sex, education, risk factors, and medial temporal atrophy, the association between the total SVD score and MoCA-J score remained significant. The total SVD score was independently associated with attention. In conclusion, the total SVD score, cerebral SVD burden, was independently association with global cognitive function and attention. A strategy to reduce SVD burden will have the potential to prevent cognitive decline. A total of 648 patients with any evidence of cerebral small vessel disease (SVD) in MRI and at least one vascular risk factor underwent Mini-mental State Examination (MMSE) and Japanese version of the Montreal Cognitive Assessment (MoCA-J) global cognitive tests. The total SVD scores count the presence of each SVD-related findings (white matter hyperintensity, Lacunar infarction, cerebral microbleeds and enlarged perivascular space), ranging from 0 to 4, as the SVD burden. Total SVD scores were significantly associated with MoCA-J scores (r = -0.203, P < 0.001). After adjustment for age, sex, education, risk factors, and medial temporal atrophy, the association between the total SVD score and global cognitive scores remained significant.

White matter hyperintensities in cholinergic pathways may predict poorer responsiveness to acetylcholinesterase inhibitor treatment for Alzheimer's disease

BACKGROUND

Acetylcholinesterase inhibitor (AChEI) drug regimens are the mainstay treatment options for patients with Alzheimer's disease (AD). Herein, We examined the association between clinical response to AChEI and white matter hyperintensities on magnetic resonance imaging (MRI) scan at baseline.

METHODS

Between 2020 and 2021, we recruited 101 individuals with a clinical diagnosis of probable AD. Each participant underwent complete neuropsychological testing and 3T (Telsa) brain magnetic resonance imaging. Responsiveness to AChEI, as assessed after 12 months, was designated as less than two points of regression in Mini-Mental State Examination scores (MMSE) and stable clinical dementia rating scale. We also evaluated MRI images by examining scores on the Cholinergic Pathways Hyperintensities Scale (CHIPS), Fazekas scale, and medial temporal atrophy (MTA) scale.

RESULTS

In our cohort, 52 patients (51.4%) were classified as responders. We observed significantly higher CHIPS scores in the nonresponder group (21.1 ± 12.9 vs. 14.9 ± 9.2, P = 0.007). Age at baseline, education level, sex, Clinical Dementia Rating sum of boxes scores, and three neuroimaging parameters were tested in regression models. Only CHIPS scores predicted clinical response to AChEI treatment.

CONCLUSION

WMHs in the cholinergic pathways, not diffuse white matter lesions or hippocampal atrophy, correlated with poorer responsiveness to AChEI treatment. Therefore, further investigation into the role of the cholinergic pathway in AD is warranted.

Research Progress on MRI for White Matter Hyperintensity of Presumed Vascular Origin and Cognitive Impairment

White matter hyperintensity of presumed vascular origin (WMH) is a common medical imaging manifestation in the brains of middle-aged and elderly individuals. WMH can lead to cognitive decline and an increased risk of cognitive impairment and dementia. However, the pathogenesis of cognitive impairment in patients with WMH remains unclear. WMH increases the risk of cognitive impairment, the nature and severity of which depend on lesion volume and location and the patient's cognitive reserve. Abnormal changes in microstructure, cerebral blood flow, metabolites, and resting brain function are observed in patients with WMH with cognitive impairment. Magnetic resonance imaging (MRI) is an indispensable tool for detecting WMH, and novel MRI techniques have emerged as the key approaches for exploring WMH and cognitive impairment. This article provides an overview of the association between WMH and cognitive impairment and the application of dynamic contrast-enhanced MRI, structural MRI, diffusion tensor imaging, 3D-arterial spin labeling, intravoxel incoherent motion, magnetic resonance spectroscopy, and resting-state functional MRI for examining WMH and cognitive impairment.