Development and validation of a priori risk model for extensive white matter lesions in people age 65 years or older: the Dijon MRI study

Impact of blood pressure variability and cerebral small vessel disease: A systematic review and meta-analysis

Importance

Abnormal blood pressure pattern is an independent risk factor for vascular events. Blood pressure variability can predict cardiovascular and cerebrovascular disease outcomes and is closely associated with the risk of cognitive impairment. However, the relationship between blood pressure variability and cerebral small vessel disease neuroimaging markers remains unclear. This study aimed to evaluate the relationship between blood pressure variability and cerebral small vessel disease neuroimaging markers.

Data sources

We searched multiple databases, including Embase, Web of Science, PubMed, Cochrane Library, UpToDate, and World of Science, from their inception until November 27, 2023.Main Outcomes and Measures: A meta-analysis of 19 observational studies involving 14519 participants was performed. Findings: ①Systolic blood pressure variability was correlated with the cerebral small vessel disease total burden, white matter hyperintensities and lacunar infarction; ② Diastolic blood pressure variability was correlated with the cerebral small vessel disease total burden, white matter hyperintensities and cerebral microbleeds; ③ Non-dipping patterns were correlated with white matter hyperintensities and lacunar infarction. ④ Reverse-dipping patterns were significantly correlated with white matter hyperintensities and cerebral microbleeds.

Conclusions

and Relevance: Blood pressure variability correlates with neuroimaging markers of cerebral small vessel disease and its burden. Hence, early monitoring and intervention of blood pressure variability may be essential for the early diagnosis, prevention and treatment of cerebral small vessel disease.

Development and validation of a predictive model for white matter lesions in young- and middle-aged people

Background

White matter lesion (WML) is an age-related disorder associated with stroke and cognitive impairment. This study aimed to investigate the risk factors and build a predictive model of WML in young- and middle-aged people.

Methods

We performed a second analysis of the data from the Dryad Digital Repository. We selected those people who are <60 years old and randomly divided them into the training group and the validation group. We investigated the risk factors of WML in the training group with logistic regression analysis and built a prediction nomogram based on multivariate logistic regression analysis; finally, the performance of the prediction nomogram was evaluated for discrimination, accuracy, and clinical utility.

Results

There were 308 people in the training group and 723 people in the validation group. Multivariate regression analysis showed that the age (OR = 1.49, 95% CI: 1.31-1.70), diastolic blood pressure (OR = 1.02, 95% CI: 1.00-1.03), carotid plaque score (OR = 1.31, 95% CI: 1.14-1.50), female gender (OR = 2.27, 95% CI: 1.56-3.30), and metabolic syndrome (OR = 2.12, 95% CI: 1.22-3.70) were significantly associated with white matter lesions. The area under the curve value (AUC) of the receiver operating curve (ROC) was 0.734 for the training group and 0.642 for the validation group. The calibration curve and clinical impact curve showed that the prediction nomogram has good accuracy and clinical application value.

Conclusion

Age, diastolic blood pressure, carotid plaque score, female gender, and metabolic syndrome were risk factors in young- and middle-aged people <60 years old with WML, and the nomogram based on these risk factors showed good discrimination, accuracy, and clinical utility.

Structural and functional MRI correlates of T2 hyperintensities of brain white matter in young neurologically asymptomatic adults

OBJECTIVES

Although white matter hyperintensities (WMHs) are quite commonly found incidentally, their aetiology, structural characteristics, and functional consequences are not entirely known. The purpose of this study was to quantify WMHs in a sample of young, neurologically asymptomatic adults and evaluate the structural and functional correlations of lesion load with changes in brain volume, diffusivity, and functional connectivity.

METHODS

MRI brain scan using multimodal protocol was performed in 60 neurologically asymptomatic volunteers (21 men, 39 women, mean age 34.5 years). WMHs were manually segmented in 3D FLAIR images and counted automatically. The number and volume of WMHs were correlated with brain volume, resting-state functional MRI (rs-fMRI), and diffusion tensor imaging (DTI) data. Diffusion parameters measured within WMHs and normally appearing white matter (NAWM) were compared.

RESULTS

At least 1 lesion was found in 40 (67%) subjects, median incidence was 1 lesion (interquartile range [IQR] = 4.5), and median volume was 86.82 (IQR = 227.23) mm³. Neither number nor volume of WMHs correlated significantly with total brain volume or volumes of white and grey matter. Mean diffusivity values within WMHs were significantly higher compared with those for NAWM, but none of the diffusion parameters of NAWM were significantly correlated with WMH load. Both the number and volume of WMHs were correlated with the changes of functional connectivity between several regions of the brain, mostly decreased connectivity of the cerebellum.

CONCLUSIONS

WMHs are commonly found even in young, neurologically asymptomatic adults. Their presence is not associated with brain atrophy or global changes of diffusivity, but the increasing number and volume of these lesions correlate with changes of brain connectivity, and especially that of the cerebellum.

KEY POINTS

• White matter hyperintensities (WMHs) are commonly found in young, neurologically asymptomatic adults. • The presence of WMHs is not associated with brain atrophy or global changes of white matter diffusivity. • The increasing number and volume of WMHs correlate with changes of brain connectivity, and especially with that of the cerebellum.

A Neuroimaging Marker Based on Diffusion Tensor Imaging and Cognitive Impairment Due to Cerebral White Matter Lesions

Background: The peak width of skeletonized mean diffusivity (PSMD) is a new, fully automated, robust imaging marker for cerebral small vessel disease (SVD), strongly associated with processing speed. However, it has never been applied to cerebral white matter lesions (WMLs). Our study aimed to investigate the correlation between PSMD and cognition, particularly in the executive function of patients with WMLs. Methods: A total of 111 WML patients and 50 healthy controls (HCs) were enrolled, and their demographic information and cardiovascular disease risk factors were recorded. Subjects were divided into three groups: WMLs with normal cognition (WMLs-NC), WMLs with vascular cognitive impairment (WMLs-VCI), and HCs. They underwent conventional head magnetic resonance imaging and diffusion tensor imaging (DTI), followed by neuropsychological and psychological examinations, including the Montreal Cognitive Assessment (MoCA), and the executive function tests. We compared executive function and PSMD among the three groups and analyzed the correlation between PSMD and cognitive function in all subjects. Results: There were no significant differences in demographic characteristics (age, sex, education level, and cardiovascular disease risk factors) among the three groups (P > 0.05), but there were significant differences in global cognition (P < 0.0001), executive function (P < 0.0001), and PSMD (P < 0.0001). The average PSMD value (×10^-4 mm²/s) was 2.40 ± 0.23, 2.68 ± 0.30, and 4.51 ± 0.39 in the HC, WMLs-NC, and WMLs-VCI groups, respectively. There was no correlation between PSMD and cognition in the HC group, but PSMD was significantly correlated with MoCA scores (r = -0.3785, P < 0.0001) and executive function (r = -0.4744, P < 0.0001) in the WMLs-NC group and in the WMLs-VCI group (r = -0.4448, P < 0.0001 and r = -0.6279, P < 0.0001, respectively). Conclusions: WML patients have higher PSMD and worse cognitive performance than HCs, and PSMD is strongly associated with global cognition and executive functions in WML patients. This result provides new insights into the pathophysiology of cognitive impairment in WML patients. PSMD could be a surrogate marker for disease progression and could thus be used in therapeutic trials involving WML patients.