White matter lesion severity is associated with reduced cognitive performances in patients with normal CSF Abeta42 levels

Regional white matter hyperintensity volume predicts persistent cognitive impairment in acute lacunar infarct patients

Background

White matter hyperintensity (WMH) is often described in acute lacunar stroke (ALS) patients. However, the specific relationship between regional WMH volume and persistent cognitive impairment remains unclear.

Methods

We enrolled patients with ALS who were hospitalized at the First Affiliated Hospital of Soochow University between January 2020 and November 2022. All patients were assessed for global cognitive function using the Montreal Cognitive Assessment (MoCA) scale at 14 ± 2 days and 6 months after the onset of ALS. Manifestations of chronic cerebral small vessel disease (CSVD) were assessed via MRI scan. The distributions of regional WMH were segmented, and their relationship with cognitive impairment was evaluated.

Results

A total of 129 patients were enrolled. Baseline frontal WMH volume (OR = 1.18, P = 0.04) was an independent risk factor for long-term cognitive impairment after ALS. Furthermore, the presence of WMH at the genu of the corpus callosum (GCC) at baseline (OR = 3.1, P = 0.033) was strongly associated with persistent cognitive decline. Multivariable logistic regression analysis showed that depression (OR = 6.252, P = 0.029), NIHSS score (OR = 1.24, P = 0.011), and albumin at admission (OR = 0.841, P = 0.032) were also important determinants of long-term cognitive impairment after ALS.

Conclusions

Our study found that WMH, especially frontal WMH volume and the presence of WMH at the GCC at baseline, independently contributed to long-term cognitive decline in ALS patients. This study provides new evidence of the clinical relationship between regional WMH volume and cognitive impairment in ALS patients.

Associations of multiple visual rating scales based on structural magnetic resonance imaging with disease severity and cerebrospinal fluid biomarkers in patients with Alzheimer’s disease

The relationships between multiple visual rating scales based on structural magnetic resonance imaging (sMRI) with disease severity and cerebrospinal fluid (CSF) biomarkers in patients with Alzheimer’s disease (AD) were ambiguous. In this study, a total of 438 patients with clinically diagnosed AD were recruited. All participants underwent brain sMRI scan, and medial temporal lobe atrophy (MTA), posterior atrophy (PA), global cerebral atrophy-frontal sub-scale (GCA-F), and Fazekas rating scores were visually evaluated. Meanwhile, disease severity was assessed by neuropsychological tests such as the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and Clinical Dementia Rating (CDR). Among them, 95 patients were tested for CSF core biomarkers, including Aβ_1–42, Aβ_1–40, Aβ_1–42/Aβ_1–40, p-tau, and t-tau. As a result, the GCA-F and Fazekas scales showed positively significant correlations with onset age (r = 0.181, p < 0.001; r = 0.411, p < 0.001, respectively). Patients with late-onset AD (LOAD) showed higher GCA-F and Fazekas scores (p < 0.001, p < 0.001). With regard to the disease duration, the MTA and GCA-F were positively correlated (r = 0.137, p < 0.05; r = 0.106, p < 0.05, respectively). In terms of disease severity, a positively significant association emerged between disease severity and the MTA, PA GCA-F, and Fazekas scores (p < 0.001, p < 0.001, p < 0.001, p < 0.05, respectively). Moreover, after adjusting for age, gender, and APOE alleles, the MTA scale contributed to moderate to severe AD in statistical significance independently by multivariate logistic regression analysis (p < 0.05). The model combining visual rating scales, age, gender, and APOE alleles showed the best performance for the prediction of moderate to severe AD significantly (AUC = 0.712, sensitivity = 51.5%, specificity = 84.6%). In addition, we observed that the MTA and Fazekas scores were associated with a lower concentration of Aβ_1–42 (p < 0.031, p < 0.022, respectively). In summary, we systematically analyzed the benefits of multiple visual rating scales in predicting the clinical status of AD. The visual rating scales combined with age, gender, and APOE alleles showed best performance in predicting the severity of AD. MRI biomarkers in combination with CSF biomarkers can be used in clinical practice.

Brain amyloid and vascular risk are related to distinct white matter hyperintensity patterns

White matter hyperintensities (WMHs) are associated with vascular risk and Alzheimer's disease. In this study, we examined relations between WMH load and distribution, amyloid pathology and vascular risk in 339 controls and cases with either subjective (SCD) or mild cognitive impairment (MCI). Regional deep (DWMH) and periventricular (PWMH) WMH loads were determined using an automated algorithm. We stratified on Aβ1-42 pathology (Aβ+/-) and analyzed group differences, as well as associations with Framingham Risk Score for cardiovascular disease (FRS-CVD) and age. Occipital PWMH (p = 0.001) and occipital DWMH (p = 0.003) loads were increased in SCD-Aβ+ compared with Aβ- controls. In MCI-Aβ+ compared with Aβ- controls, there were differences in global WMH (p = 0.003), as well as occipital DWMH (p = 0.001) and temporal DWMH (p = 0.002) loads. FRS-CVD was associated with frontal PWMHs (p = 0.003) and frontal DWMHs (p = 0.005), after adjusting for age. There were associations between global and all regional WMH loads and age. In summary, posterior WMH loads were increased in SCD-Aβ+ and MCI-Aβ+ cases, whereas frontal WMHs were associated with vascular risk. The differences in WMH topography support the use of regional WMH load as an early-stage marker of etiology.

White matter hyperintensities and risks of cognitive impairment and dementia: A systematic review and meta-analysis of 36 prospective studies

BACKGROUND

White matter hyperintensities of presumed vascular origin (WMH) are one of the imaging features of cerebral small vessel disease. Controversies persist about the effects of WMH on cognitive dysfunction. This meta-analysis aimed to identify the associations of WMH with risks of cognitive impairment and dementia.

METHODS

We searched PubMed, EMBASE and Cochrane Library for prospective studies. Primary analyses of cognitive dysfunction and sub-analyses of specific outcomes and study characteristics were conducted using random-effect models.

RESULTS

Thirty-six prospective studies with 19,040 participants were included. WMH at baseline conferred a 14 % elevated risk of cognitive impairment and all-cause dementia (ACD). WMH also conferred 25 % elevated risk of Alzheimer's disease and 73 % elevated risk of vascular dementia. Risk effects of high-grade WMH and continually increasing WMH (in volume or severity) on ACD were revealed. Periventricular WMH conferred a 1.51-fold excess risk for dementia.

CONCLUSIONS

WMH were associated with increased risk of cognitive dysfunction and could become a neuroimaging indicator of dementia.

Association between atherosclerosis and Alzheimer's disease: A systematic review and meta-analysis

BACKGROUND

To evaluate the relationship between atherosclerosis and Alzheimer's disease (AD), we conducted a systematic review and meta-analysis to study the difference of carotid intima-media thickness (CIMT) and the prevalence of atherosclerosis between AD patients and non-AD controls.

METHODS

The studies on the association between atherosclerosis and AD were manually searched in PubMed, Embase, Cochrane Library, and CNKI (China National Knowledge Infrastructure) spanned to September 2018 according to PRISMA (the Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines.

RESULTS

Thirteen studies were included in the final analysis, seven studies with data on the mean CIMT (610 cases and 417 controls) and ten studies reporting on the prevalence of atherosclerosis (1,698 cases and 6,452 controls). Compared with controls, AD group showed a significantly higher CIMT (overall standard mean difference = 0.94; 95% CI, 0.48-1.40; p < .0001) and an increased prevalence of atherosclerosis (OR = 1.46; 95% CI, 1.26-1.68; p < .0001).

CONCLUSIONS

Atherosclerosis is significantly associated with AD. CIMT might be a useful marker to predict the risk of AD and assess the vascular burden. The finding is also important for possible prevention and treatment of AD in the future.

Prevalence and risk of progression of preclinical Alzheimer's disease stages: a systematic review and meta-analysis

Background

Alzheimer’s disease (AD) pathology begins several years before the clinical onset. The long preclinical phase is composed of three stages according to the 2011National Institute on Aging and Alzheimer’s Association (NIA-AA) criteria, followed by mild cognitive impairment (MCI), a featured clinical entity defined as “due to AD”, or “prodromal AD”, when pathophysiological biomarkers (i.e., cerebrospinal fluid or positron emission tomography with amyloid tracer) are positive. In the clinical setting, there is a clear need to detect the earliest symptoms not yet fulfilling MCI criteria, in order to proceed to biomarker assessment for diagnostic definition, thus offering treatment with disease-modifying drugs to patients as early as possible. According to the available evidence, we thus estimated the prevalence and risk of progression at each preclinical AD stage, with special interest in Stage 3.

Methods

Cross-sectional and longitudinal studies published from April 2008 to May 2018 were obtained through MEDLINE-PubMed, screened, and systematically reviewed by four independent reviewers. Data from included studies were meta-analyzed using random-effects models. Heterogeneity was assessed by I² statistics.

Results

Estimated overall prevalence of preclinical AD was 22% (95% CI = 18–26%). Rate of biomarker positivity overlapped in cognitively normal individuals and people with subjective cognitive decline. The risk of progression increases across preclinical AD stages, with individuals classified as NIA-AA Stage 3 showing the highest risk (73%, 95% CI = 40–92%) compared to those in Stage 2 (38%, 95% CI = 21–59%) and Stage 1 (20%, 95% CI = 10–34%).

Conclusion

Available data consistently show that risk of progression increases across the preclinical AD stages, where Stage 3 shows a risk of progression comparable to MCI due to AD. Accordingly, an effort should be made to also operationalize the diagnostic work-up in subjects with subtle cognitive deficits not yet fulfilling MCI criteria. The possibility to define, in the clinical routine, a patient as “pre-MCI due to AD” could offer these subjects the opportunity to use disease-modifying drugs at best.

Electronic supplementary material

The online version of this article (10.1186/s13195-018-0459-7) contains supplementary material, which is available to authorized users.

White matter lesion load increases the risk of low CSF Aβ42 in apolipoprotein E-ɛ4 carriers attending a memory clinic

BACKGROUND

White matter lesions (WMLs) are age-related manifestations of ischemic cerebrovascular disease and increase the risk for Alzheimer's disease (AD). The apolipoprotein E (ApoE) ɛ4 allele is a risk factor for late onset AD and has been related to low cerebrospinal fluid (CSF) Aβ42 levels and to cerebrovascular disease. The present study analyzed the relationship between WMLs, ApoE-ɛ4 genotype, and low CSF Aβ42.

METHODS

A total of 235 memory clinic attenders were stratified in 3 groups according to WML load. WMLs were rated on axial T2 magnetic resonance imaging images. Group 1 had no or only small amounts of periventricular (PV) or subcortical (SC) WMLs, WML group 2 had high amounts of PV WMLs and low amounts of SC WMLs, and WML group 3 had high amounts of both PV and SC WMLs. In each WML group, ApoE-ɛ4 genotype was used in logistic regression as a predictor for low CSF Aβ42 (cutoff≤450 ng/L).

RESULTS

The odds ratio (OR) of having low CSF Aβ42 was significantly increased in the presence of ApoE-ɛ4 only in WML group 3 (OR 3.69, P=.009).

CONCLUSION

A high WML load may interact with the ApoE-ɛ4 genotype and increase the risk for reduced CSF Aβ42 in patients attending a memory clinic.

Pre-dementia memory impairment is associated with white matter tract affection

Mild cognitive impairment (MCI), especially amnestic, often represents pre-dementia Alzheimer's disease, characterized by medial temporal lobe atrophy, while white matter (WM) alterations are insufficiently described. We analyze both cortical morphometric and WM diffusivity differences in amnestic versus non-amnestic subtypes and ask if memory and WM tract affection are related independently of cortical atrophy. Forty-nine patients from a university-hospital based memory clinic with a score of 3 on the Global Deterioration Scale aged 43-77 years (45% female) were included. Two neuropsychologists have classified cases as amnestic (aMCI), non-amnestic (naMCI), or less advanced (laMCI), not satisfying criteria for aMCI/naMCI. Diffusion tensor imaging (DTI) WM tract and morphometric data of the temporal-parietal memory network were compared among patient subtypes and related to story, word list, and visual memory. WM radial and mean diffusivity (DR and MD), underlying the entorhinal cortex, were higher in aMCI compared with laMCI. WM DR and MD, underlying the entorhinal, parahippocampal, and middle temporal cortex, explained unique variance in word list and story memory, and this was not due to secondary effects of cortical thinning. DTI may thus potentially aid diagnosis in early disease stages. ).

White matter diffusivity predicts memory in patients with subjective and mild cognitive impairment and normal CSF total tau levels

Subjective and mild cognitive impairment (SCI and MCI) are etiologically heterogeneous conditions. This poses problems for assessment of pathophysiological mechanisms and risk of conversion to dementia. Neuropsychological, imaging, and cerebrospinal fluid (CSF) findings serve to distinguish Alzheimer's disease (AD) and other etiological subgroups. Tau-molecules stabilize axonal microtubuli; high CSF total tau (T-tau) reflects ongoing axonal damage consistent with AD. Here, we stratify patients by CSF T-tau pathology to determine if memory network diffusion tensor imaging (DTI) predicts memory performance in the absence of elevated T-tau. We analyzed neuropsychological test results, hippocampus volume (HcV) and white matter diffusivity in 45 patients (35 with normal T-tau). The T-tau pathology group showed more hippocampus atrophy and memory impairment than the normal T-tau group. In the T-tau normal group: (1) memory was related with white matter diffusivity [fractional anisotropy (FA) and radial diffusivity (DR)], and (2) FA of the genu corpus callosum was a unique predictor of variance for verbal learning, and HcV did not contribute to this prediction. The smaller sample size in the T-tau pathology group precludes firm conclusions. In the normal T-tau group, white matter tract and memory changes may be associated with normal aging, or with non-tau related pathological mechanisms.