Alterations in Dynamic Functional Connectivity in Patients with Cerebral Small Vessel Disease

Cerebral small vessel disease (CSVD) is a common disease that seriously endangers people's health, and is easily overlooked by both patients and clinicians due to its near-silent onset. Dynamic functional connectivity (DFC) is a new concept focusing on the dynamic features and patterns of brain networks that represents a powerful tool for gaining novel insight into neurological diseases. To assess alterations in DFC in CSVD patients, and the correlation of DFC with cognitive function. We enrolled 35 CSVD patients and 31 normal control subjects (NC). Resting-state functional MRI (rs-fMRI) with a sliding-window approach and k-means clustering based on independent component analysis (ICA) was used to evaluate DFC. The temporal properties of fractional windows and the mean dwell time in each state, as well as the number of transitions between each pair of DFC states, were calculated. Additionally, we assessed the functional connectivity (FC) strength of the dynamic states and the associations of altered neuroimaging measures with cognitive performance. A dynamic analysis of all included subjects suggested four distinct functional connectivity states. Compared with the NC group, the CSVD group had more fractional windows and longer mean dwell times in state 4 characterized by sparse FC both inter-network and intra-networks. Additionally, the CSVD group had a reduced number of windows and shorter mean dwell times compared to the NC group in state 3 characterized by highly positive FC between the somatomotor and visual networks, and negative FC in the basal ganglia and somatomotor and visual networks. The number of transitions between state 2 and state 3 and between state 3 and state 4 was significantly reduced in the CSVD group compared to the NC group. Moreover, there was a significant difference in the FC strength between the two groups, and the altered temporal properties of DFC were significantly related to cognitive performance. Our study indicated that CSVD is characterized by altered temporal properties in DFC that may be sensitive neuroimaging biomarkers for early disease identification. Further study of DFC alterations could help us to better understand the progressive dysfunction of networks in CSVD patients.

Analysis of gait pattern related to high cerebral small vessel disease burden using quantitative gait data from wearable sensors

BACKGROUND AND OBJECTIVES

Sensor-based wearable devices help to obtain a wide range of quantitative gait parameters, which provides sufficient data to investigate disease-specific gait patterns. Although cerebral small vessel disease (CSVD) plays a significant role in gait impairment, the specific gait pattern associated with a high burden of CSVD remains to be explored.

METHODS

We analyzed the gait pattern related to high CSVD burden from 720 participants (aged 55-65 years, 42.5 % male) free of neurological disease in the Taizhou Imaging Study. All participants underwent detailed quantitative gait assessments (obtained from an insole-like wearable gait tracking device) and brain magnetic resonance imaging examinations. Thirty-three gait parameters were summarized into five gait domains. Sparse sliced inverse regression was developed to extract the gait pattern related to high CSVD burden.

RESULTS

The specific gait pattern derived from several gait domains (i.e., angles, phases, variability, and spatio-temporal) was significantly associated with the CSVD burden (OR=1.250, 95 % CI: 1.011-1.546). The gait pattern indicates that people with a high CSVD burden were prone to have smaller gait angles, more stance time, more double support time, larger gait variability, and slower gait velocity. Furthermore, people with this gait pattern had a 25 % higher risk of a high CSVD burden.

CONCLUSIONS

We established a more stable and disease-specific quantitative gait pattern related to high CSVD burden, which is prone to facilitate the identification of individuals with high CSVD burden among the community residents or the general population.

Pathology-based brain arterial disease phenotypes and their radiographic correlates

INTRODUCTION

Brain arterial diseases, including atherosclerosis, vasculitis, and dissections, are major contributors to cerebrovascular morbidity and mortality worldwide. These diseases not only increase the risk of stroke but also play a significant role in neurodegeneration and dementia. Clear and unambiguous terminology and classification of brain arterial disease phenotypes is crucial for research and clinical practice.

MATERIAL AND METHODS

This review aims to summarize and harmonize the terminology used for brain large and small arterial phenotypes based on pathology studies and relate them to imaging phenotypes used in medical research and clinical practice.

CONCLUSIONS AND RESULTS

Arteriosclerosis refers to hardening of the arteries but does not specify the underlying etiology. Specific terms such as atherosclerosis, calcification, or non-atherosclerotic fibroplasia are preferred. Atherosclerosis is defined pathologically by an atheroma. Other brain arterial pathologies occur and should be distinguished from atherosclerosis given therapeutic implications. On brain imaging, intracranial arterial luminal stenosis is usually attributed to atherosclerosis in the presence of atherosclerotic risk factors but advanced high-resolution arterial wall imaging has the potential to more accurately identify the underlying pathology. Regarding small vessel disease, arteriosclerosis is ambiguous and arteriolosclerosis is often used to denote the involvement of arterioles rather than arteries. Lipohyalinosis is sometimes used synonymously with arteriolosclerosis, but less accurately describes this common small vessel thickening which uncommonly shows lipid. Specific measures of small vessel wall thickness, the relationship to the lumen as well as changes in the layer composition might convey objective, measurable data regarding the status of brain small vessels.

Pathological Changes of Small Vessel Disease in Intracerebral Hemorrhage: a Systematic Review and Meta-analysis

In intracerebral hemorrhage (ICH) with pathology-proven etiology, we performed a systematic review and meta-analysis to elucidate the association between cerebral amyloid angiopathy (CAA) and arteriolosclerosis, and directly compared MRI and pathological changes of markers of cerebral small vessel disease (CSVD). Studies enrolling primary ICH who had received an etiological diagnosis through biopsy or autopsy were searched using Ovid MEDLINE, PubMed, and Web of Science from inception to June 8, 2022. We extracted pathological changes of CSVD for each patient whenever available. Patients were grouped into CAA + arteriolosclerosis, strict CAA, and strict arteriolosclerosis subgroups. Of 4155 studies identified, 28 studies with 456 ICH patients were included. The frequency of lobar ICH (p<0.001) and total microbleed number (p=0.015) differed among patients with CAA + arteriolosclerosis, strict CAA, and strict arteriolosclerosis. Concerning pathology, severe CAA was associated with arteriolosclerosis (OR 6.067, 95% CI 1.107-33.238, p=0.038), although this association was not statistically significant after adjusting for age and sex. Additionally, the total microbleed number (median 15 vs. 0, p=0.006) was higher in ICH patients with CAA evidence than those without CAA. The pathology of CSVD imaging markers was mostly investigated in CAA-ICH. There was inconsistency concerning CAA severity surrounding microbleeds. Small diffusion-weighted imaging lesions could be matched to acute microinfarct histopathologically. Studies that directly correlated MRI and pathology of lacunes, enlarged perivascular spaces, and atrophy were scarce. Arteriolosclerosis might be associated with severe CAA. The pathological changes of CSVD markers by ICH etiology are needed to be investigated further.

Association of NOTCH3 Variant Risk Category With 2-Year Clinical and Radiologic Small Vessel Disease Progression in Patients With CADASIL

BACKGROUND AND OBJECTIVES

Pathogenic variants in NOTCH3 are the main cause of hereditary cerebral small vessel disease (SVD). SVD-associated NOTCH3 variants have recently been categorized into high risk (HR), moderate risk (MR), or low risk (LR) for developing early-onset severe SVD. The most severe NOTCH3-associated SVD phenotype is also known as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). We aimed to investigate whether NOTCH3 variant risk category is associated with 2-year progression rate of SVD clinical and neuroimaging outcomes in CADASIL.

METHODS

A single-center prospective 2-year follow-up study was performed of patients with CADASIL. Clinical outcomes were incident stroke, disability (modified Rankin Scale), and executive function (Trail Making Test B given A t-scores). Neuroimaging outcomes were mean skeletonized mean diffusivity (MSMD), normalized white matter hyperintensity volume (nWMHv), normalized lacune volume (nLV), and brain parenchymal fraction (BPF). Cox regression and mixed-effect models, adjusted for age, sex, and cardiovascular risk factors, were used to study 2-year changes in outcomes and differences in disease progression between patients with HR-NOTCH3 and MR-NOTCH3 variants.

RESULTS

One hundred sixty-two patients with HR (n = 90), MR (n = 67), and LR (n = 5) NOTCH3 variants were included. For the entire cohort, there was 2-year mean progression for MSMD (β = 0.20, 95% CI 0.17-0.23, p = 7.0 × 10-24), nLV (β = 0.13, 95% CI 0.080-0.19, p = 2.1 × 10-6), nWMHv (β = 0.092, 95% CI 0.075-0.11, p = 8.8 × 10-20), and BPF (β = -0.22, 95% CI -0.26 to -0.19, p = 3.2 × 10-22), as well as an increase in disability (p = 0.002) and decline of executive function (β = -0.15, 95% CI -0.30 to -3.4 × 10-5, p = 0.05). The HR-NOTCH3 group had a higher probability of 2-year incident stroke (hazard ratio 4.3, 95% CI 1.4-13.5, p = 0.011), and a higher increase in MSMD (β = 0.074, 95% CI 0.013-0.14, p = 0.017) and nLV (β = 0.14, 95% CI 0.034-0.24, p = 0.0089) than the MR-NOTCH3 group. Subgroup analyses showed significant 2-year progression of MSMD in young (n = 17, β = 0.014, 95% CI 0.0093-0.019, p = 1.4 × 10-5) and premanifest (n = 24, β = 0.012, 95% CI 0.0082-0.016, p = 1.1 × 10-6) individuals.

DISCUSSION

In a trial-sensitive time span of 2 years, we found that patients with HR-NOTCH3 variants have a significantly faster progression of major clinical and neuroimaging outcomes, compared with patients with MR-NOTCH3 variants. This has important implications for clinical trial design and disease prediction and monitoring in the clinic. Moreover, we show that MSMD is a promising outcome measure for trials enrolling premanifest individuals.

Retinal Ischemic Perivascular Lesion Reflects Cerebral Small Vessel Disease Burden in Single Subcortical Infarction

BACKGROUND

Retinal ischemic perivascular lesions (RIPLs) are an indicator of ischemia in the middle retina. We aimed to determine the relationship between RIPLs and single subcortical infarction (SSI). We also investigated the differences in cerebral small vessel disease imaging burden between groups with and without RIPLs in SSI.

METHODS AND RESULTS

In this case-control study, we enrolled 82 patients with SSI and 72 nonstroke controls. All participants underwent magnetic resonance imaging and swept-source optical coherence tomography/optical coherence tomography angiography. Small vessel disease markers such as lacunes, cerebral microbleeds, white matter hyperintensity, and perivascular spaces were rated on brain imaging. RIPLs were assessed via swept-source optical coherence tomography. Optical coherence tomography angiography was used to measure the superficial vascular complex and deep vascular complex of the retina. After adjusting for risk factors, the presence of RIPLs was significantly associated with SSI (odds ratio [OR], 1.506 [95% CI, 1.365-1.662], P<0.001). Eyes with RIPLs showed lower deep vascular complex density (P=0.035) compared with eyes without RIPLs in patients with SSI. After adjusting for vascular risk factors, the presence of RIPLs in patients with SSI was associated with an increased periventricular white matter hyperintensity burden (β=0.414 [95% CI, 0.181-0.647], P<0.001) and perivascular spaces-basal ganglia (β=0.296 [95% CI, 0.079-0.512], P=0.008).

CONCLUSIONS

RIPLs are associated with SSI independent of underlying risk factors. The relationship between the presence of RIPLs and small vessel disease markers provides evidence that RIPLs might be an additional indicator of cerebral ischemic changes.

SGLT1 and SGLT2 inhibition, circulating metabolites, and cerebral small vessel disease: a mediation Mendelian Randomization study

BACKGROUND

Sodium-glucose cotransporter 2 (SGLT2) and SGLT1 inhibitors may have additional beneficial metabolic effects on circulating metabolites beyond glucose regulation, which could contribute to a reduction in the burden of cerebral small vessel disease (CSVD). Accordingly, we used Mendelian Randomization (MR) to examine the role of circulating metabolites in mediating SGLT2 and SGLT1 inhibition in CSVD.

METHODS

Genetic instruments for SGLT1/2 inhibition were identified as genetic variants, which were both associated with the expression of encoding genes of SGLT1/2 inhibitors and glycated hemoglobin A1c (HbA1c) level. A two-sample two-step MR was used to determine the causal effects of SGLT1/2 inhibition on CSVD manifestations and the mediating effects of 1400 circulating metabolites linking SGLT1/2 inhibition with CSVD manifestations.

RESULTS

A lower risk of deep cerebral microbleeds (CMBs) and small vessel stroke (SVS) was linked to genetically predicted SGLT2 inhibition. Better white matter structure integrity was also achieved, as evidenced by decreased mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD), as well as lower deep (DWMH) and periventrivular white matter hyperintensity (PWMH) volume. Inhibiting SGLT2 could also lessen the incidence of severe enlarged perivascular spaces (EPVS) located at white matter, basal ganglia (BG) and hippocampus (HIP). SGLT1 inhibition could preserve white matter integrity, shown as decreased MD of white matter and DWMH volume. The effect of SGLT2 inhibition on SVS and MD of white matter through the concentration of 4-acetamidobutanoate and the cholesterol to oleoyl-linoleoyl-glycerol (18:1 to 18:2) ratio, with a mediated proportion of 30.3% and 35.5% of the total effect, respectively.

CONCLUSIONS

SGLT2 and SGLT1 inhibition play protective roles in CSVD development. The SGLT2 inhibition could lower the risk of SVS and improve the integrity of white matter microstructure via modulating the level of 4-acetamidobutanoate and cholesterol metabolism. Further mechanistic and clinical studies research are needed to validate our findings.

Sporadic cerebral small vessel disease and cognitive decline in healthy older adults: A systematic review and meta-analysis

We performed a systematic review and meta-analysis on prospective studies that provided risk estimates for the impact of 3 different MRI markers of small vessel disease (SVD), namely white matter hyperintensities (WMH), cerebral microbleeds (CMB) and lacunes, on cognitive decline in relatively healthy older adults without cognitive deficits at baseline. A total of 23 prospective studies comprising 11,486 participants were included for analysis. Extracted data was pooled, reviewed and meta-analysed separately for global cognition, executive function, memory and attention. The pooled effect size for the association between cerebral SVD and cognitive decline was for global cognition -0.10 [-0.14; -0.05], for executive functioning -0.18 [-0.24; - 0.11], for memory -0.12 [-0.17; -0.07], and for attention -0.17 [-0.23; -0.11]. Results for the association of individual MRI markers of cerebral SVD were statistically significant for WMH and global cognition -0.15 [-0.24; -0.06], WMH and executive function -0.23 [-0.33; -0.13], WMH and memory -0.19 [-0.29; -0.09], WMH and attention -0.24 [-0.39; -0.08], CMB and executive function -0.07 [-0.13; -0.02], CMB and memory -0.11 [-0.21; -0.02] and CMB and attention -0.13 [-0.25; -0.02]. In conclusion, presence of MRI markers of cerebral SVD were found to predict an increased risk of cognitive decline in relatively healthy older adults. While WMH were found to significantly affect all cognitive domains, CMB influenced decline in executive functioning over time as well as (in some studies) decline in memory and attention.

Retinal vascular density as a potential biomarker of diabetic cerebral small vessel disease

AIM

The retina and brain share similar anatomical and physiological features. Thus, retinal imaging by optical coherence tomography angiography (OCTA) might be a potential tool for the early diagnosis of diabetic cerebral small vessel disease (CSVD). In this study, we aimed to evaluate retinal vascular density (VD) in diabetic CSVD by OCTA imaging and explore the associations between retinal VD and cerebral magnetic resonance imaging (MRI) markers and cognitive function.

METHODS

In total, 131 patients were enrolled, including CSVD (n = 43) and non-CSVD groups (n = 88). The VD and foveal avascular zone of the retinal capillary plexus were measured with OCTA. A brain MRI was performed.

RESULTS

MRI imaging showed that in the diabetic CSVD group, white matter hyperintensities (WMHs), particularly deep WMHs (58.82%), are the most common MRI marker, followed by cerebral microbleeds in the subtentorial and cortical areas (34.78%). The CSVD group showed increases in the prevalence of cognitive dysfunction (p = .034) and depression (p = .033) and decreases in visuospatial/executive ability and delayed recall ability. In the CSVD group, VDs of the macular superficial vascular plexus (32.93 ± 7.15% vs. 36.97 ± 6.59%, p = .002), intermediate capillary plexus (20.87 ± 4.30% vs. 23.08 ± 4.30%, p = .005) and deep capillary plexus (23.54 ± 5.00% vs. 26.05 ± 4.20%, p = .003) were lower than those of the non-CSVD group. Multiple linear regression analysis showed that VD of the macular superficial vascular plexus was independently associated with cerebral microbleeds. Meanwhile, VD of the macular intermediate capillary plexus was associated with white matter lacunar infarcts after adjustment.

CONCLUSIONS

Diabetic CSVDs are characterized by MRI markers, including deep WMHs and cerebral microbleeds, and showed impaired cognition with decreased visuospatial/executive ability and delayed recall ability. OCTA imaging revealed a significant decrease in retinal microvascular perfusion in diabetic CSVD, which was related to MRI markers and cognitive function. OCTA might be a valuable potential measurement for the early diagnosis of CSVD.

Cerebral microbleeds and risk of symptomatic hemorrhagic transformation following mechanical thrombectomy for large vessel ischemic stroke

BACKGROUND AND PURPOSE

In patients with acute ischemic stroke (AIS) treated with endovascular therapy (EVT), the association of pre-existing cerebral small vessel disease (cSVD) with symptomatic intracerebral hemorrhage (sICH) remains controversial. We tested the hypothesis that the presence of cerebral microbleeds (CMBs) and their burden would be associated with sICH after EVT of AIS.

METHODS

We conducted a retrospective study combining cohorts of patients that underwent EVT between January 1st 2015 and January 1st 2020. CMB presence, burden, and other cSVD markers were assessed on a pre-treatment MRI, evaluated independently by two observers. Primary outcome was the occurrence of sICH.

RESULTS

445 patients with pretreatment MRI were included, of which 70 (15.7%) demonstrated CMBs on baseline MRI. sICH occurred in 36 (7.6%) of all patients. Univariate analysis did not demonstrate an association between CMB and the occurrence of sICH (7.5% in CMB+ group vs 8.6% in CMB group, p = 0.805). In multivariable models, CMBs' presence was not significantly associated with increased odds for sICH (-aOR- 1.19; 95% CI [0.43-3.27], p = 0.73). Only ASPECTs (aOR 0.71 per point increase; 95% CI [0.60-0.85], p < 0.001) and collaterals status (aOR 0.22 for adequate versus poor collaterals; 95% CI [0.06-0.93], p 0.019) were independently associated with sICH.

CONCLUSION

CMB presence and burden is not associated with increased occurrence of sICH after EVT. This result incites not to exclude patients with CMBs from EVT. The risk of sICH after EVT in patients with more than10 CMBs will require further investigation.

REGISTRATION

Registration-URL: http://www.

CLINICALTRIALS

gov ; Unique identifier: NCT01062698.

The thalamic covariance network is associated with cognitive deficits in patients with cerebral small vascular disease

OBJECTIVE

Abnormalities in the gray matter structure of cerebral small vessel disease (CSVD) have been observed throughout the brain. However, whether cortico-cortical connections exist between regions of gray matter atrophy in patients with CSVD has not been fully elucidated. This question was tested by comparing the gray matter covariance networks in CSVD patients with and without cognitive impairment (CI).

METHODS

We performed multivariate modeling of the gray matter volume measurements of 61 patients with CI (CSVD-CI), 85 patients without CI (CSVD-NC), and 108 healthy controls using source-based morphological analysis (SBM) to obtain gray matter structural covariance networks at the population level. Then, correlations between structural covariance networks and cognitive functions were analyzed in CSVD patients. Finally, a support vector machine (SVM) classifier was used with the gray matter covariance network as a classification feature to identify CI among the CSVD population.

RESULTS

The results of the analysis of all the subjects showed that compared with healthy controls, the expression of the thalamic covariance network, cerebellum covariance network, and calcarine cortex covariance network was reduced in patients with CSVD. Moreover, CSVD-CI patients showed a significant reduction in the expression of the thalamic covariance network, encompassing the thalamus and the parahippocampal gyrus, relative to CSVD-NC patients, which persisted after excluding CSVD patients with thalamic lacunes. In patients with CSVD, cognitive functions were positively correlated with measures of the thalamic covariance network. More than 80% of CSVD patients with CI were correctly identified by the SVM classifier.

INTERPRETATION

Our findings provide new evidence to explain the distribution state of gray matter reduction in CSVD patients, and the thalamic covariance network is the core region for early gray matter reduction during the development of CSVD disease, which is related to cognitive deficits. Reduced expression of thalamic covariance networks may provide a neuroimaging biomarker for the early identification of cognitive impairment in CSVD patients.

Effect of cerebral small vessel disease on the integrity of cholinergic system in mild cognitive impairment patients: a longitudinal study

We aimed to investigate the effect of cerebral small vessel disease (SVD) on cholinergic system integrity in mild cognitive impairment (MCI) patients. Nucleus basalis of Meynert (NBM) volume and cholinergic pathways integrity was evaluated at baseline, 1-, 2-, and 4-year follow-ups in 40 cognitively unimpaired (CU) participants, 29 MCI patients without SVD, and 23 MCI patients with SVD. We compared cholinergic markers among three groups and examined their associations with SVD burden in MCI patients. We used linear mixed models to assess longitudinal changes in cholinergic markers over time among groups. Mediation analysis was employed to investigate the mediating role of cholinergic system degeneration between SVD and cognitive impairment. Increased mean diffusivity (MD) in medial and lateral pathways was observed in MCI patients with SVD compared to those without SVD and CU participants. Both MCI groups showed decreased NBM volume compared to CU participants, while there was no significant difference between the two MCI groups. Longitudinally, compared to CU participants, MCI patients with SVD displayed a more rapid change in MD in both pathways, but not in NBM volume. Furthermore, SVD burden was associated with cholinergic pathway disruption and its faster rate of change in MCI patients. However, mediation analyses showed that cholinergic pathways did not mediate significant indirect effects of SVD burden on cognitive impairment. Our findings suggest that SVD could accelerate the degeneration of cholinergic pathways in MCI patients. However, they do not provide evidence to support that SVD could contribute to cognitive impairment through cholinergic system injury.

Distinct spatial contributions of amyloid pathology and cerebral small vessel disease to hippocampal morphology

INTRODUCTION

Cerebral small vessel disease (SVD) and amyloid beta (Aβ) pathology frequently co-exist. The impact of concurrent pathology on the pattern of hippocampal atrophy, a key substrate of memory impacted early and extensively in dementia, remains poorly understood.

METHODS

In a unique cohort of mixed Alzheimer's disease and moderate-severe SVD, we examined whether total and regional neuroimaging measures of SVD, white matter hyperintensities (WMH), and Aβ, as assessed by 18F-AV45 positron emission tomography, exert additive or synergistic effects on hippocampal volume and shape.

RESULTS

Frontal WMH, occipital WMH, and Aβ were independently associated with smaller hippocampal volume. Frontal WMH had a spatially distinct impact on hippocampal shape relative to Aβ. In contrast, hippocampal shape alterations associated with occipital WMH spatially overlapped with Aβ-vulnerable subregions.

DISCUSSION

Hippocampal degeneration is differentially sensitive to SVD and Aβ pathology. The pattern of hippocampal atrophy could serve as a disease-specific biomarker, and thus guide clinical diagnosis and individualized treatment strategies for mixed dementia.

Cerebral small vessel disease increases risk for epilepsy: a Mendelian randomization study

BACKGROUND

Despite previous research suggesting a potential association between cerebral small vessel disease (CSVD) and epilepsy, the precise causality and directionality between cerebral small vessel disease (CSVD) and epilepsy remain incompletely understood. We aimed to investigate the causal link between CSVD and epilepsy.

METHOD

A bidirectional two-sample Mendelian randomization (MR) analysis was performed to evaluate the causal relationship between CSVD and epilepsy. The analysis included five dimensions of CSVD, namely small vessel ischemic stroke (SVS), intracerebral hemorrhage (ICH), white matter damage (including white matter hyperintensity [WMH], fractional anisotropy, and mean diffusivity), lacunar stroke, and cerebral microbleeds. We also incorporated epilepsy encompassing both focal epilepsy and generalized epilepsy. Inverse variance weighted (IVW) was used as the primary estimate while other four MR techniques were used to validate the results. Pleiotropic effects were controlled by adjusting vascular risk factors through multivariable MR.

RESULT

The study found a significant association between SVS (odds ratio [OR] 1.117, PFDR = 0.022), fractional anisotropy (OR 0.961, PFDR = 0.005), mean diffusivity (OR 1.036, PFDR = 0.004), and lacunar stroke (OR 1.127, PFDR = 0.007) with an increased risk of epilepsy. The aforementioned correlations primarily occurred in focal epilepsy rather than generalized epilepsy on subgroup analysis and retained their significance in the multivariable MR analysis.

CONCLUSION

Our study demonstrated that genetic susceptibility to CSVD independently elevates the risk of epilepsy, especially focal epilepsy. Diffusion tensor imaging may help screen patients at high risk for epilepsy in CSVD. Improved management of CSVD may be a significant approach in reducing the overall prevalence of epilepsy.

Microbleeds in Heterozygous HTRA1-Related Cerebral Small Vessel Disease

This case report describes the evaluation of a 44-year-old man with a history of headache, dizziness, and imbalance and imaging that showed lacunar infarctions and bilateral white matter hyperintensities.

Disrupted brain structural networks associated with depression and cognitive dysfunction in cerebral small vessel disease with microbleeds

Emerging evidence highlights cerebral microbleeds (CMBs) as hallmarks of cerebral small vessel disease (CSVD) underlying depression and cognitive dysfunction. This study aimed to reveal how depression and cognition-related white matter (WM) abnormalities are topologically presented, and the network-level structural disruptions associated with CMBs in CSVD. We used probabilistic diffusion tractography and graph theory to investigate brain WM network topology in CSVD patients with (n = 64, CSVD-c) and without (n = 138, CSVD-n) CMBs and 90 healthy controls. Then we evaluated the Pearson's correlations between disrupted network metrics and neuropsychological parameters. For global topology, the CSVD-c group exhibited significantly decreased global (Eglob) and local (Eloc) efficiency and increased shortest path length compared with the controls, while no significant difference was found between the CSVD-c and CSVD-n groups. For regional topology, although all groups showed highly similar hub distributions, compare with control group, the CSVD-c group exhibited significantly decreased nodal efficiency mainly in the bilateral supplementary motor area (SMA), median cingulate gyrus (DCG) and right orbital middle frontal gyrus, while the CSVD-n group showed significantly decreased nodal efficiency only in the right SMA. Notably, Eglob, Eloc and nodal efficiency of the right anterior cingulate gyrus, DCG, middle temporal gyrus and left insula showed significantly negative correlations with depression score, significantly positive correlations with Rey auditory verbal learning test and symbol digit modalities test scores in CSVD-n group, as well as significantly negative correlations with Stroop color-word test scores in CSVD-c group. The WM networks of CSVD patients are characterized by decreased global integration and local specialization, and decreased nodal efficiency highly related to depression and cognitive dysfunction in the attention, default mode network and sensorimotor regions. These findings provide new insight into the neurobiological mechanisms of CSVD and concomitant affective and cognitive disorders.

Correlation between migraine and cerebral small vessel disease: A case-control study

BACKGROUND

Microcirculatory pathology is one of the pathophysiological theories of migraine, which may present as visually subclinical lesions. Image markers of cerebral small vessel disease (CSVD) have been investigated in elderly migraineurs. However, past studies looked at only part of image features, and the conclusions may have been hindered by confounding factors. The relationship between migraine and CSVD signs needs reliable demonstrations.

METHODS

We conducted a case-control study by recruiting episodic young migraineurs from a tertiary headache centre, with tension-type headache (TTH) and healthy controls. Distinct image features of microvascular damage and baseline characteristics across groups were assessed, and multivariate linear regression was performed to evaluate the risk factors for image abnormalities in migraineurs.

RESULTS

Forty-eight migraineurs, 32 TTHs and 49 healthy controls were included. The median age was 32 year-old. 58.7% of the participants were female. The Scheltens score and volume of white matter hyperintensities (WMHs) in migraineurs, and the number of Virchow-Robin spaces (VRSs) in both migraineurs and TTHs were different from those in normal controls. No lacunar infarct-like lesions (ILLs) or cerebral microbleeds (CMBs) were found. Age, education level (high level: β = -2.23, lobar WMHs), attack duration (long duration: β = 3.81, lobar WMHs) and attack frequency were independent risk factors for Scheltens score and volume of WMH in migraineurs. Migraine aura (β = -2.389), attack frequency and education level were correlated with the number of VRSs.

CONCLUSIONS

Migraine was associated with WMHs and VRSs. Aura, attack duration, attack frequency, age and education level were risk factors for image abnormalities of CVSD in migraineurs.

SIGNIFICANCE

This study provides a novel and comprehensive landscape of CSVD MRI features in young migraineurs, and it fills the blank of CMBs and VRSs which received less attention, with more persuasive, more reliable and stronger evidence of the association between CSVD and migraine. Our results also imply some new feature of TTH and the possible pathophysiology of the migraine course as well as new clues for the early management of migraine in terms of visual brain damage.

Cerebral small vessel disease and stroke: Linked by stroke aetiology, but not stroke lesion location or size

BACKGROUND

Cerebral small vessel disease (SVD) has previously been associated with worse stroke outcome, vascular dementia, and specific post-stroke cognitive deficits. The underlying causal mechanisms of these associations are not yet fully understood. We investigated whether a relationship between SVD and certain stroke aetiologies or a specific stroke lesion anatomy provides a potential explanation.

METHODS

In a retrospective observational study, we examined 859 patients with first-ever, non-SVD anterior circulation ischemic stroke (age = 69.0±15.2). We evaluated MRI imaging markers to assess an SVD burden score and mapped stroke lesions on diffusion-weighted MRI. We investigated the association of SVD burden with i) stroke aetiology, and ii) lesion anatomy using topographical statistical mapping.

RESULTS

With increasing SVD burden, stroke of cardioembolic aetiology was more frequent (ρ = 0.175; 95 %-CI = 0.103;0.244), whereas cervical artery dissection (ρ = -0.143; 95 %-CI = -0.198;-0.087) and a patent foramen ovale (ρ = -0.165; 95 %-CI = -0.220;-0.104) were less frequent stroke etiologies. However, no significant associations between SVD burden and stroke aetiology remained after additionally controlling for age (all p>0.125). Lesion-symptom-mapping and Bayesian statistics showed that SVD burden was not associated with a specific stroke lesion anatomy or size.

CONCLUSIONS

In patients with a high burden of SVD, non-SVD stroke is more likely to be caused by cardioembolic aetiology. The common risk factor of advanced age may link both pathologies and explain some of the existing associations between SVD and stroke. The SVD burden is not related to a specific stroke lesion location.

Presenilin-1 mutation position influences amyloidosis, small vessel disease, and dementia with disease stage

INTRODUCTION

Amyloidosis, including cerebral amyloid angiopathy, and markers of small vessel disease (SVD) vary across dominantly inherited Alzheimer's disease (DIAD) presenilin-1 (PSEN1) mutation carriers. We investigated how mutation position relative to codon 200 (pre-/postcodon 200) influences these pathologic features and dementia at different stages.

METHODS

Individuals from families with known PSEN1 mutations (n = 393) underwent neuroimaging and clinical assessments. We cross-sectionally evaluated regional Pittsburgh compound B-positron emission tomography uptake, magnetic resonance imaging markers of SVD (diffusion tensor imaging-based white matter injury, white matter hyperintensity volumes, and microhemorrhages), and cognition.

RESULTS

Postcodon 200 carriers had lower amyloid burden in all regions but worse markers of SVD and worse Clinical Dementia Rating® scores compared to precodon 200 carriers as a function of estimated years to symptom onset. Markers of SVD partially mediated the mutation position effects on clinical measures.

DISCUSSION

We demonstrated the genotypic variability behind spatiotemporal amyloidosis, SVD, and clinical presentation in DIAD, which may inform patient prognosis and clinical trials.

HIGHLIGHTS

Mutation position influences Aβ burden, SVD, and dementia. PSEN1 pre-200 group had stronger associations between Aβ burden and disease stage. PSEN1 post-200 group had stronger associations between SVD markers and disease stage. PSEN1 post-200 group had worse dementia score than pre-200 in late disease stage. Diffusion tensor imaging-based SVD markers mediated mutation position effects on dementia in the late stage.

Memory deficit in patients with cerebral small vessel disease: evidence from eye tracking technology

Cerebral small vessel disease is the one of the most prevalent causes of vascular cognitive impairment. We aimed to find objective and process-based indicators related to memory function to assist in the detection of memory impairment in patients with cerebral small vessel disease. Thirty-nine cerebral small vessel disease patients and 22 healthy controls were invited to complete neurological examinations, neuropsychological assessments, and eye tracking tasks. Eye tracking indicators were recorded and analyzed in combination with imaging features. The cerebral small vessel disease patients scored lower on traditional memory task and performed worse on eye tracking memory task performance compared to the healthy controls. The cerebral small vessel disease patients exhibited longer visit duration and more visit count within areas of interest and targets and decreased percentage value of total visit duration on target images to total visit duration on areas of interest during decoding stage among all levels. Our results demonstrated the cerebral small vessel disease patients performed worse in memory scale and eye tracking memory task, potentially due to their heightened attentional allocation to nontarget images during the retrieval stage. The eye tracking memory task could provide process-based indicators to be a beneficial complement to memory assessment and new insights into mechanism of memory impairment in cerebral small vessel disease patients.

Understanding the relationship between type-2 diabetes, MRI markers of neurodegeneration and small vessel disease, and dementia risk: a mediation analysis

To explore to which extent neurodegeneration and cerebral small vessel disease (SVD) could mediate the association between type-2 diabetes and higher dementia risk. The analytical sample consisted in 2228 participants, out of the Three-City study, aged 65 and older, free of dementia at baseline who underwent brain MRI. Diabetes was defined by medication intake or fasting or non-fasting elevated glucose levels. Dementia status was assessed every 2 to 3 years, during up to 12 years of follow-up. Brain parenchymal fraction (BPF) and white matter hyperintensities volume (WMHV) were selected as markers of neurodegeneration and cerebral SVD respectively. We performed a mediation analysis of the effect of baseline BPF and WMHV (mediators) on the association between diabetes and dementia risk using linear and Cox models adjusted for age, sex, education level, hypertension, hypercholesterolemia, BMI, smoking and alcohol drinking status, APOE-ε4 status, and study site. At baseline, 8.8% of the participants had diabetes. Diabetes (yes vs. no) was associated with higher WMHV (βdiab = 0.193, 95% CI 0.040; 0.346) and lower BPF (βdiab = -0.342, 95% CI -0.474; -0.210), as well as with an increased risk of dementia over 12 years of follow-up (HRdiab = 1.65, 95% CI 1.04; 2.60). The association between diabetes status and dementia risk was statistically mediated by higher WMHV (HRdiab=1.05, 95% CI 1.01; 1.11, mediated part = 10.8%) and lower BPF (HRdiab = 1.12, 95% CI 1.05; 1.20, mediated part = 22.9%). This study showed that both neurodegeneration and cerebral SVD statistically explained almost 30% of the association between diabetes and dementia.

Discontinuity of deep medullary veins in SWI is associated with deep white matter hyperintensity volume and cognitive impairment in cerebral small vessel disease

BACKGROUND

Discontinuation of the deep medullary veins (DMVs) may be an early imaging marker for identifying cognitive impairment caused by cerebral small vessel disease (CSVD). However, this method lacks mechanistic exploration. We aimed to investigate whether the DMV score is related to CSVD imaging markers and cognitive impairment in patients with CSVD.

METHODS

This retrospective study included patients with CSVD who completed DMV score and cognition (e.g., MMSE, MoCA) assessments, and underwent MRI scanning (T2-FLAIR for white matter hyperintensities (WMH) volume, T1-weighted MRI for brain parenchymal fractions (BPF) analysis, and SWI for assessment of DMV score). The CSVD imaging markers were quantitatively assessed using the AccuBrain® system. We assessed the diagnostic value of neuroimaging biomarkers for detecting CSVD-related cognitive impairment. In addition, we explored the relationship between the DMV score, CSVD imaging markers, and cognition using mediation analysis.

RESULTS

Ninety-four patients with CSVD were divided into a cognitive impairment group (n = 39) and a non-cognitive impairment group (n = 55). Higher DMV scores, larger WMH volumes, and smaller BPF were observed in the cognitive impairment group than those in the non-cognitive impairment group. Receiver operating characteristics (ROC) analysis revealed that the discovery value of the integration of patient age, BPF, whole WMH volume, and DMV score for cognitive impairment was 0.742, with a sensitivity and specificity of 79.5 % and 61.5 %, respectively. Mediation analysis showed mediation by WMH and BPF in the relationship between DMV score and cognitive impairment (all P < 0.05).

LIMITATIONS

This study did not evaluate the DMV score in subregions according to DMV anatomy.

CONCLUSIONS

The DMV score is significantly associated with cognitive impairment in patients with CSVD, and this association is mediated through WMH and BPF.

Clinical Phenotypes Associated With Cerebral Small Vessel Disease: An Overview of Systematic Reviews

BACKGROUND AND OBJECTIVES

Cerebral small vessel disease (cSVD) causes lacunar and hemorrhagic stroke and is an important contributor to vascular cognitive impairment. Other potential physical and psychological consequences of cSVD have been described across various body systems. Descriptions of cSVD are available in journals specific to those individual body systems, but a comprehensive assessment of clinical manifestations across this disparate literature is lacking. We conducted an overview of systematic reviews describing clinical cSVD phenotypes.

METHODS

We searched multidisciplinary databases from inception to December 2023. We included reviews describing concurrent clinical phenotypes in individuals with neuroimaging evidence of cSVD, defined using the STandards for ReportIng Vascular changes on nEuroimaging criteria. We broadly classified phenotypes into cognitive, mood and neuropsychiatric, respiratory, cardiovascular, renal-urinary, peripheral nervous system, locomotor, and gastrointestinal. We included both studies assessing multiple cSVD features and studies examining individual cSVD markers. We extracted risk factor-adjusted effect estimates, where possible, and assessed methodologic quality using the Assessment of Multiple Systematic Reviews-2 tool.

RESULTS

After screening 6,156 publications, we included 24 systematic reviews reporting on 685 original studies and 1,135,943 participants. Cognitive and neuropsychiatric phenotypes were examined most often, particularly in relation to white matter hyperintensities (range of risk ratios [RRs] for cognitive phenotypes 1.21-1.49, range of 95% CI 1.01-1.84; for neuropsychiatric, RR 1.02-5.71, 95% CI 0.96-19.69). Two reviews focused solely on perivascular spaces. No reviews assessed lacunes or small subcortical infarcts separately from other cSVD features. Reviews on peripheral nervous system, urinary, or gastrointestinal phenotypes were lacking. Fourteen reviews had high methodologic quality, 5 had moderate quality, and 5 had low quality. Heterogeneity in cSVD definitions and phenotypic assessments was substantial.

DISCUSSION

Neuroimaging markers of cSVD are associated with various clinical manifestations, suggesting a multisystem phenotype. However, features classically associated with cSVD, for example, gait, had limited supporting evidence, and for many body systems, there were no available reviews. Similarly, while white matter hyperintensities were relatively well studied, there were limited data on phenotypes associated with other cSVD features. Future studies should characterize the full clinical spectrum of cSVD and explore clinical associations beyond neurocognitive and neuropsychiatric presentations.

Overall cerebral small vessel disease burden is associated with outcome of acute ischemic stroke after mechanical thrombectomy

OBJECTIVES

To investigate the association between the overall cerebral small vessel disease (CSVD) burden and the therapeutic outcome of mechanical thrombectomy (MT) in patients with acute anterior circulation large-vessel occlusion stroke.

MATERIALS AND METHODS

Data of patients who achieved successful revascularization after MT for acute anterior circulation large-vessel occlusion stroke in the Ningbo Medical Center Lihuili Hospital between April 2017 and January 2022 were retrospectively analyzed. The overall CSVD burden was evaluated by total CSVD score based on MRI images. According to the 90-day modified Rankin Scale (mRS) score, the participants were divided into the Good outcome group (mRS score 0-2) and Poor outcome group (mRS score 3-6). Multivariate Logistic regression was applied to assess the relationship between the overal CSVD burdern and 90-day outcome.

RESULTS

In total, 145 eligible patients were included and classified into the Good outcome group (n = 77, 62.3% males, mean age: 64.92 ± 13.67 years) and Poor outcome group (n = 68, 50% males, mean age: 69.76 ± 10.88 years). Symptomatic intracranial hemorrhage (OR = 2.788, 95%CI: 1.143-8.745, P = 0.048), poor preoperative collateral status (OR = 3.619, 95%CI: 1.670-7.844, P = 0.001), and high total CSVD score (score 2: OR = 3.800, 95%CI: 1.173 = 12.311, P = 0.026; score 3: OR = 7.529, 95%CI: 1.555-36.460, P = 0.012) were independently prognostic for poor 90-day outcome in patients receiving MT.

CONCLUSION

This study identified that the overall CSVD burden was independently associated with the prognosis of patients receiving MT for acute anterior circulation large-vessel occlusion stroke.

Relationship of neutrophil/lymphocyte ratio with cerebral small vessel disease and its common imaging markers

BACKGROUND

High neutrophil/lymphocyte ratio (NLR) is associated with poor prognosis in ischemic stroke. However, the role of NLR in cerebral small vessel disease (CSVD) is controversial. Herein, we evaluated the value of NLR in identifying CSVD and its relationship with the common imaging markers of CSVD.

METHODS

A total of 667 patients were enrolled in this study, including 368 in the CSVD group and 299 in the non-CSVD group. Clinical, laboratory, and imaging data were collected. The relationship of NLR with CSVD and common imaging markers of CSVD were analyzed with univariate and multivariate logistic regression analysis. The predictive value of NLR was assessed with the receiver operating characteristic curve.

RESULTS

NLR (odds ratio [OR] = 1.929, 95% confidence interval [CI] =  1.599-2.327, p < .001) was an independent risk factor for CSVD. NLR was also independently associated with moderate to severe white matter hyperintensity (WMH) (OR = 2.136, 95% CI = 1.768-2.580, p < .001), moderate to severe periventricular WMH (OR = 2.138, 95% CI = 1.771-2.579, p < .001), and moderate to severe deep WMH (OR = 1.654, 95% CI = 1.438-1.902, p < .001), moderately to severely enlarged perivascular spaces (EPVS) (OR = 1.248, 95% CI = 1.110-1.402, p < .001), moderately to severely EPVS in the basal ganglia (OR = 1.136, 95% CI = 1.012-1.275, p = .030), and moderately to severely EPVS in the centrum semiovale (OR = 1.140, 95% CI = 1.027-1.266, p = .014). However, NLR was not statistically significantly associated with lacune. The optimal cutoff point of NLR in predicting CSVD was 2.47, with sensitivity and specificity of 84.2% and 66.9%, respectively (p < .01). The diagnostic effect was maximized when NLR was combined with other risk factors.

CONCLUSIONS

NLR is an independent risk factor for CSVD and is independently associated with common imaging markers of CSVD. NLR may serve as a valid and convenient biomarker for assessing CSVD.

Does Thrombosis Play a Causal Role in Lacunar Stroke and Cerebral Small Vessel Disease?

BACKGROUND

The importance of thromboembolism in the pathogenesis of lacunar stroke (LS), resulting from cerebral small vessel disease (cSVD), is debated, and although antiplatelets are widely used in secondary prevention after LS, there is limited trial evidence from well-subtyped patients to support this approach. We sought to evaluate whether altered anticoagulation plays a causal role in LS and cSVD using 2-sample Mendelian randomization.

METHODS

From a recent genome-wide association study (n=81 190), we used 119 genetic variants associated with venous thrombosis at genome-wide significance (P<5*10-8) and with a linkage disequilibrium r2<0.001 as instrumental variables. We also used genetic associations with stroke from the GIGASTROKE consortium (62 100 ischemic stroke cases: 10 804 cardioembolic stroke, 6399 large-artery stroke, and 6811 LS). In view of the lower specificity for LS with the CT-based phenotyping mainly used in GIGASTROKE, we also used data from patients with magnetic resonance imaging-confirmed LS (n=3199). We also investigated associations with more chronic magnetic resonance imaging features of cSVD, namely, white matter hyperintensities (n=37 355) and diffusion tensor imaging metrics (n=36 533).

RESULTS

Mendelian randomization analyses showed that genetic predisposition to venous thrombosis was associated with an increased odds of any ischemic stroke (odds ratio [OR], 1.19 [95% CI, 1.13-1.26]), cardioembolic stroke (OR, 1.32 [95% CI, 1.21-1.45]), and large-artery stroke (OR, 1.41 [95% CI, 1.26-1.57]) but not with LS (OR, 1.07 [95% CI, 0.99-1.17]) in GIGASTROKE. Similar results were found for magnetic resonance imaging-confirmed LS (OR, 0.94 [95% CI, 0.81-1.09]). Genetically predicted risk of venous thrombosis was not associated with imaging markers of cSVD.

CONCLUSIONS

These findings suggest that altered thrombosis plays a role in the risk of cardioembolic and large-artery stroke but is not a causal risk factor for LS or imaging markers of cSVD. This raises the possibility that antithrombotic medication may be less effective in cSVD and underscores the necessity for further trials in well-subtyped cohorts with LS to evaluate the efficacy of different antithrombotic regimens in LS.

The association between alpha diversity of gut microbiota, neuroimaging markers and cognitive function in cerebral small vessel disease

There is increasing recognition of gut microbial dysbiosis in cerebral small vessel disease (CSVD). The altered diversity in a single ecosystem - alpha diversity index of gut microbiota has attracted wide attention. Our study aims to determine whether the alpha diversity index differs among healthy control (HC), CSVD with and without cognitive impairment. Moreover, we investigate the correlation between the alpha diversity index, neuroimaging markers, and cognitive function. We recruited 40 HC, 43 CSVD patients without cognitive impairment (CSVD-NCI), and 35 CSVD patients with mild cognitive impairment (CSVD-MCI). Clinical and neuropsychological assessments, MRI scanning, and gut microbiota analysis were performed on all participants. The alpha diversity indexes Chao1 and Shannon were calculated to evaluate community richness and diversity in a sample, respectively. Individual neuroimaging markers of CSVD and the CSVD burden score were also evaluated. A significantly lower level of Chao 1 rather than the Shannon index was observed in the CSVD subgroups than in the HC group. The level of the Chao 1 index was negatively correlated with both CMB counts, a neuroimaging characteristic of CSVD, and CSVD burden score in patients with CSVD. Additionally, the Chao 1 index has been associated with general cognitive function, information processing speed, and language function in patients with CSVD. Remarkably, the increased CSVD burden score mediated the effects of decreased levels of Chao 1 on information processing speed and language function. Hence, the alterations in species richness may be associated with CSVD-related cognitive impairment and mediated by CSVD neuroimaging markers.

Chronic kidney disease and its association with cerebral small vessel disease in the general older hypertensive population

BACKGROUND

Cerebral small vessel disease can be identified using magnetic resonance imaging, and includes white matter hyperintensities, lacunar infarcts, cerebral microbleeds, and brain atrophy. Cerebral small vessel disease and chronic kidney disease share many risk factors, including hypertension. This study aims to explore an association between chronic kidney disease and cerebral small vessel disease, and also to explore the role of hypertension in this relationship.

METHODS

With a cross sectional study design, data from 390 older adults was retrieved from the general population study Good Aging in Skåne. Chronic kidney disease was defined as glomerular filtration rate < 60 ml/min/1,73m2. Associations between chronic kidney disease and magnetic resonance imaging markers of cerebral small vessel disease were explored using logistic regression models adjusted for age and sex. In a secondary analysis, the same calculations were performed with the study sample stratified based on hypertension status.

RESULTS

In the whole group, adjusted for age and sex, chronic kidney disease was not associated with any markers of cerebral small vessel disease. After stratification by hypertension status and adjusted for age and sex, we observed that chronic kidney disease was associated with cerebral microbleeds (OR 1.93, CI 1.04-3.59, p-value 0.037), as well as with cortical atrophy (OR 2.45, CI 1.34-4.48, p-value 0.004) only in the hypertensive group. In the non-hypertensive group, no associations were observed.

CONCLUSIONS

In this exploratory cross-sectional study, we observed that chronic kidney disease was associated with markers of cerebral small vessel disease only in the hypertensive subgroup of a general population of older adults. This might indicate that hypertension is an important link between chronic kidney disease and cerebral small vessel disease. Further studies investigating the relationship between CKD, CSVD, and hypertension are warranted.

Long-Term Longitudinal Course of Cognitive and Motor Symptoms in Patients With Cerebral Small Vessel Disease

BACKGROUND AND OBJECTIVES

Patients with cerebral small vessel disease (SVD) show a heterogenous clinical course. The aim of the current study was to investigate the longitudinal course of cognitive and motor function in patients who developed parkinsonism, dementia, both, or none.

METHODS

Participants were from the Radboud University Nijmegen Diffusion Tensor and Magnetic Resonance Cohort study, a prospective cohort of patients with SVD. Parkinsonism and dementia were, respectively, diagnosed according to the UK Parkinson's Disease Society brain bank criteria and the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, criteria for major neurocognitive disorder. Linear and generalized linear mixed-effect analyses were used to study the longitudinal course of motor and cognitive tasks.

RESULTS

After a median follow-up of 12.8 years (interquartile range 10.2-15.3), 132 of 501 (26.3%) participants developed parkinsonism, dementia, or both. Years before diagnosis of these disorders, participants showed distinct clinical trajectories from those who developed none: Participant who developed parkinsonism had an annual percentage of 22% (95% CI 18%-27%) increase in motor part of the Unified Parkinson's Disease Rating Scale score. This was significantly higher than the 16% (95% CI 14%-18%) of controls, mainly because of a steep increase in bradykinesia and posture and gait disturbances. When they developed dementia as well, the increase in Timed Up and Go Test time of 0.73 seconds per year (95% CI 0.58-0.87) was significantly higher than the 0.20 seconds per year increase (95% CI 0.16-0.23) of controls. All groups, including the participants who developed parkinsonism without dementia, showed a faster decline in executive function compared with controls: Annual decline in Z-score was -0.07 (95% CI -0.10 to -0.05), -0.09 (95% CI -0.11 to -0.08), and -0.11 (95% CI -0.14 to -0.08) for participants who developed, respectively, parkinsonism, dementia, and both parkinsonism and dementia. These declines were all significantly faster than the annual decline in Z-score of 0.07 (95% CI -0.10 to -0.05) of controls.

DISCUSSION

A distinct pattern in deterioration of clinical markers is visible in patients with SVD, years before the diagnosis of parkinsonism and dementia. This knowledge aids early identification of patients with a high risk of developing these disorders.

Assessment of Small Vessel Function Using 7T MRI in Patients With Sporadic Cerebral Small Vessel Disease: The ZOOM@SVDs Study

BACKGROUND AND OBJECTIVES

Cerebral small vessel disease (cSVD) is a major cause of stroke and dementia, but little is known about disease mechanisms at the level of the small vessels. 7T-MRI allows assessing small vessel function in vivo in different vessel populations. We hypothesized that multiple aspects of small vessel function are altered in patients with cSVD and that these abnormalities relate to disease burden.

METHODS

Patients and controls participated in a prospective observational cohort study, the ZOOM@SVDs study. Small vessel function measures on 7T-MRI included perforating artery blood flow velocity and pulsatility index in the basal ganglia and centrum semiovale, vascular reactivity to visual stimulation in the occipital cortex, and reactivity to hypercapnia in the gray and white matter. Lesion load on 3T-MRI and cognitive function were used to assess disease burden.

RESULTS

Forty-six patients with sporadic cSVD (mean age ± SD 65 ± 9 years) and 22 matched controls (64 ± 7 years) participated in the ZOOM@SVDs study. Compared with controls, patients had increased pulsatility index (mean difference 0.09, p = 0.01) but similar blood flow velocity in basal ganglia perforating arteries and similar flow velocity and pulsatility index in centrum semiovale perforating arteries. The duration of the vascular response to brief visual stimulation in the occipital cortex was shorter in patients than in controls (mean difference -0.63 seconds, p = 0.02), whereas reactivity to hypercapnia was not significantly affected in the gray and total white matter. Among patients, reactivity to hypercapnia was lower in white matter hyperintensities compared with normal-appearing white matter (blood-oxygen-level dependent mean difference 0.35%, p = 0.001). Blood flow velocity and pulsatility index in basal ganglia perforating arteries and reactivity to brief visual stimulation correlated with disease burden.

DISCUSSION

We observed abnormalities in several aspects of small vessel function in patients with cSVD indicative of regionally increased arteriolar stiffness and decreased reactivity. Worse small vessel function also correlated with increased disease burden. These functional measures provide new mechanistic markers of sporadic cSVD.

Cognitive profile in cerebral small vessel disease: comparison between cerebral amyloid angiopathy and hypertension-related microangiopathy

Cerebral amyloid angiopathy (CAA) is recognized as a cause of cognitive impairment, but its cognitive profile needs to be characterized, also respect to hypertension-related microangiopathy (HA). We aimed at comparing difference or similarity of CAA and HA patients' cognitive profiles, and their associated factors. Participants underwent an extensive clinical, neuropsychological, and neuroimaging protocol. HA patients (n = 39) were more frequently males, with history of vascular risk factors than CAA (n = 32). Compared to HA, CAA patients presented worse performance at MoCA (p = 0.001) and semantic fluency (p = 0.043), and a higher prevalence of amnestic MCI (46% vs. 68%). In univariate analyses, multi-domain MCI was associated with worse performance at MoCA, Rey Auditory Verbal Learning Test (RAVLT), and semantic fluency in CAA patients, and with worse performance at Symbol Digit Modalities Test (SDMT) and phonemic fluency in HA ones. In multivariate models, multi-domain deficit remained as the only factor associated with RAVLT (β = - 0.574) in CAA, while with SDMT (β = - 0.364) and phonemic fluency (β = - 0.351) in HA. Our results highlight different patterns of cognitive deficits in CAA or HA patients. While HA patients' cognitive profile was confirmed as mainly attentional/executive, a complex cognitive profile, characterized also by deficit in semantic memory, seems the hallmark of CAA patients.

Clinical features and associated factors of coexisting intracerebral hemorrhage in patients with cerebral small vessel disease: a cross-sectional study

Intracerebral hemorrhage (ICH) is generally considered to be closely related to cerebral small vessel disease (CSVD), leading to a poor prognosis. However, the coexistence of ICH in general CSVD patients and related factors remain underreported. In our cross-sectional study, we screened 414 CSVD patients from a database at the Department of Neurology, First Affiliated Hospital of Zhengzhou University (September 2018 to April 2022). Imaging biomarkers of CSVD and coexisting ICH lesion were assessed. Factors associated with coexisting ICH in CSVD were determined using multivariate logistic regression analysis. ICH was observed in 59 patients (14.3%). Multivariate logistic regression showed that previous history of ischemic stroke or transient ischemic attack (OR 5.189, 95%CI 2.572-10.467, P < 0.001), high-grade perivascular space in the basal ganglia (n > 10) (OR 2.051, 95%CI 1.044-4.027, P = 0.037) and low adjusted calcium-phosphorus product (OR 0.728 per 1 [mmol/L]2 increase, 95%CI 0.531-0.998, P = 0.049) were associated with coexisting ICH in CSVD patients. The considerable proportion of coexisting ICH and revelation of associated factors in general CSVD patients alert physicians of the potential risk of the reoccurrence of ICH, and might have a significant impact on therapeutic strategies.

Blood Pressure Partially Mediated the Association of Insulin Resistance and Cerebral Small Vessel Disease: A Community-Based Study

BACKGROUND

Insulin resistance as a significant vascular risk factor has been studied in relation to cerebral small vessel disease (SVD). Evidence suggests that insulin resistance might trigger high blood pressure (BP). Therefore, we aimed to investigate whether insulin resistance impacts SVD with a mediating effect of BP in nondiabetic subjects.

METHODS AND RESULTS

PRECISE (Polyvascular Evaluation for Cognitive Impairment and Vascular Events) study participants underwent brain and vascular imaging techniques and metabolomic risk factors measurements. Insulin resistance was evaluated by the insulin sensitivity index and the Homeostatic Model Assessment for Insulin Resistance based on the standard oral glucose tolerance test. On average, 2752 nondiabetic subjects (47.1% men) aged 60.9 years were included. The multivariable logistic regression model and linear regression model tested the association of insulin resistance with BP components (including systolic BP [SBP], diastolic BP (DBP), and pulse pressure [PP]) and SVD, and of BP components with SVD. In the mediation analysis, SBP, DBP, and PP were found to partially mediate the detrimental effect of insulin resistance (assessed by the insulin sensitivity index) on lacunes (mediation percentage: SBP, 31.15%; DBP, 34.21%; PP, 10.43%), white matter hyperintensity (mediation percentage: SBP, 37.34%; DBP, 44.15%; PP, 9.80%), and SVD total burden (mediation percentage: SBP, 42.07%; DBP, 49.29%; PP, 11.71%) (all P<0.05). The mediation analysis results were not significant when using the Homeostatic Model Assessment for Insulin Resistance to assess insulin resistance.

CONCLUSIONS

Higher insulin resistance was associated with SVD in this community-dwelling population. The association of insulin resistance with lacunes, white matter hyperintensity, and SVD total burden was explained in part by BP.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03178448.

Abnormal brain activities of cognitive processes in cerebral small vessel disease: A systematic review of task fMRI studies

Cerebral small vessel disease (CSVD) is characterized by widespread functional changes in the brain, as evident from abnormal brain activations during cognitive tasks. However, the existing findings in this area are not yet conclusive. We systematically reviewed 25 studies reporting task-related fMRI in five cognitive domains in CSVD, namely executive function, working memory, processing speed, motor, and affective processing. The findings highlighted: (1) CSVD affects cognitive processes in a domain-specific manner; (2) Compensatory and regulatory effects were observed simultaneously in CSVD, which may reflect the interplay between the negative impact of brain lesion and the positive impact of cognitive reserve. Combined with behavioral and functional findings in CSVD, we proposed an integrated model to illustrate the relationship between altered activations and behavioral performance in different stages of CSVD: functional brain changes may precede and be more sensitive than behavioral impairments in the early pre-symptomatic stage; Meanwhile, compensatory and regulatory mechanisms often occur in the early stages of the disease, while dysfunction/decompensation and dysregulation often occur in the late stages. Overall, abnormal hyper-/hypo-activations are crucial for understanding the mechanisms of small vessel lesion-induced behavioral dysfunction, identifying potential neuromarker and developing interventions to mitigate the impact of CSVD on cognitive function.

Aldosteronism is associated with more severe cerebral small vessel disease in hypertensive intracerebral hemorrhage

Primary aldosteronism is associated with various types of cardiovascular and cerebrovascular damage independently of hypertension. Although chronic hypertension and related cerebral arteriosclerosis are the main risk factors for intracerebral hemorrhage, the effects of aldosteronism remain poorly understood. We enrolled 90 survivors of hypertensive intracerebral hemorrhage, 21 of them with aldosteronism and 69 with essential hypertension as controls in this study. Clinical parameters and neuroimaging markers of cerebral small vessel disease were recorded, and its correlations with aldosteronism were investigated. Our results showed that the aldosteronism group (55.2 ± 9.7 years, male 47.6%) had similar hypertension severity but exhibited a higher cerebral microbleed count (interquartile range) (8.5 [2.0‒25.8] vs 3 [1.0‒6.0], P = 0.005) and higher severity of dilated perivascular space in the basal ganglia (severe perivascular space [number >20], 52.4% vs. 24.6%, P = 0.029; large perivascular space [>3 mm], 52.4% vs. 20.3%, P = 0.010), compared to those with essential hypertension (53.8 ± 11.7 years, male 73.9%). In multivariate models, aldosteronism remained an independent predictor of a higher (>10) microbleed count (odds ratio = 8.60, P = 0.004), severe perivascular space (odds ratio = 4.00, P = 0.038); the aldosterone-to-renin ratio was associated with dilated perivascular space (P = 0.043) and large perivascular space (P = 0.008). In conclusions, survivors of intracerebral hemorrhage with aldosteronism showed a tendency towards more severe hypertensive arteriopathy than the essential hypertension counterparts independently of blood pressure; aldosteronism may contribute to dilated perivascular space around the deep perforating arteries. Aldosteronism is associated with more severe cerebral small vessel disease in hypertensive intracerebral hemorrhage.

Peripheral apolipoprotein is an independent factor for enlarged perivascular space in small vessel disease

OBJECTIVE

The purpose of this study is to the relationship between peripheral apolipoproteins and cerebral small vessel disease (CSVD) imaging markers.

METHODS

We reviewed the data of a population that above 40 years old with CSVD, while free of known dementia or acute stroke. We evaluated CSVD imaging markers, including white matter hyperintensities (WMHs), enlarged perivascular spaces (EPVS), lacunas, microbleeds by MRI scans, and measured peripheral apolipoproteins.

RESULTS

After adjusting for age, sex and vascular risk factors,1) apoB and apoB/apoA-1 were related to grade of EPVS in basal ganglia(apoB:r=0.196,p<0.001;apoB/apoA-1:r=0.208,p<0.001), apoE was related to grade of EPVS in centrum semiovale (r=0.125,p=0.040); 2) apoB(OR=1.739, 95%CI=1.357-2.061, p<0.001), apoB/apoA-1(OR=1.116, 95%CI=1.037-1.761, p=0.005) and apoE(OR=1.287, 95%CI=1.036-1.599, p=0.023) were independent factors of presence of severer EPVS in basal ganglia, apoE was an independent factor of presence of severer EPVS in centrum semiovale (OR=1.235, 95%CI=1.021-1.494, p=0.029).

CONCLUSION

Our findings demonstrated peripheral apolipoproteins, including apoB, apoB/apoA-1, and apoE, were independent factor for EPVS in CSVD.

Association of Mean Upper Cervical Spinal Cord Cross-Sectional Area With Cerebral Small Vessel Disease: A Community-Based Cohort Study

BACKGROUND

The purpose of this study was to investigate the association between the mean upper cervical spinal cord cross-sectional area (MUCCA) and the risk and severity of cerebral small vessel disease (CSVD).

METHODS

Community-dwelling residents in Lishui City, China, from the cross-sectional survey in the PRECISE cohort study (Polyvascular Evaluation for Cognitive Impairment and Vascular Events) conducted from 2017 to 2019. We included 1644 of 3067 community-dwelling adults in the PRECISE study after excluding those with incorrect, incomplete, insufficient, or missing clinical or imaging data. Total and modified total CSVD scores, as well as magnetic resonance imaging features, including white matter hyperintensity, lacunes, cerebral microbleeds, enlarged perivascular spaces, and brain atrophy, were assessed at the baseline. The Spinal Cord Toolbox was used to measure the upper cervical spinal cord cross-sectional area of the C1 to C3 segments of the spinal cord and its average value was taken as MUCCA. Participants were divided into 4 groups according to quartiles of MUCCA. Associations were analyzed using linear regression models adjusted for age, sex, current smoking and drinking, medical history, intracranial volume, and total cortical volume.

RESULTS

The means±SD age of the participants was 61.4±6.5 years, and 635 of 1644 participants (38.6%) were men. The MUCCA was smaller in patients with CSVD than those without CSVD. Using the total CSVD score as a criterion, the MUCCA was 61.78±6.12 cm2 in 504 of 1644 participants with CSVD and 62.74±5.94 cm2 in 1140 of 1644 participants without CSVD. Using the modified total CSVD score, the MUCCA was 61.81±6.04 cm2 in 699 of 1644 participants with CSVD and 62.91±5.94 cm2 in 945 of 1644 without CSVD. There were statistical differences between the 2 groups after adjusting for covariates in 3 models. The MUCCA was negatively associated with the total and modified total CSVD scores (adjusted β value, -0.009 [95% CI, -0.01 to -0.003] and -0.007 [95% CI, -0.01 to -0.0006]) after adjustment for covariates. Furthermore, the MUCCA was negatively associated with the white matter hyperintensity burden (adjusted β value, -0.01 [95% CI, -0.02 to -0.003]), enlarged perivascular spaces in the basal ganglia (adjusted β value, -0.005 [95% CI, -0.009 to -0.001]), lacunes (adjusted β value, -0.004 [95% CI, -0.007 to -0.0007]), and brain atrophy (adjusted β value, -0.009 [95% CI, -0.01 to -0.004]).

CONCLUSIONS

The MUCCA and CSVD were correlated. Spinal cord atrophy may serve as an imaging marker for CSVD; thus, small vessel disease may involve the spinal cord in addition to being intracranial.

Blood-based biomarkers of cerebral small vessel disease

Age-associated cerebral small vessel disease (CSVD) represents a clinically heterogenous condition, arising from diverse microvascular mechanisms. These lead to chronic cerebrovascular dysfunction and carry a substantial risk of subsequent stroke and vascular cognitive impairment in aging populations. Owing to advances in neuroimaging, in vivo visualization of cerebral vasculature abnormities and detection of CSVD, including lacunes, microinfarcts, microbleeds and white matter lesions, is now possible, but remains a resource-, skills- and time-intensive approach. As a result, there has been a recent proliferation of blood-based biomarker studies for CSVD aimed at developing accessible screening tools for early detection and risk stratification. However, a good understanding of the pathophysiological processes underpinning CSVD is needed to identify and assess clinically useful biomarkers. Here, we provide an overview of processes associated with CSVD pathogenesis, including endothelial injury and dysfunction, neuroinflammation, oxidative stress, perivascular neuronal damage as well as cardiovascular dysfunction. Then, we review clinical studies of the key biomolecules involved in the aforementioned processes. Lastly, we outline future trends and directions for CSVD biomarker discovery and clinical validation.

SERPINA3: A novel inflammatory biomarker associated with cerebral small vessel disease burden in ischemic stroke

BACKGROUND AND OBJECTIVE

Inflammation has emerged as a prominent risk factor for cerebral small vessel disease (CSVD). However, the specific association between various inflammatory biomarkers and the development of CSVD remains unclear. Serine proteinase inhibitor A3 (SERPINA3), Matrix metalloproteinase-9 (MMP-9), Tissue inhibitor metalloproteinase-1 (TIMP-1), Monocyte Chemoattractant Protein-1 (MCP-1) are several inflammatory biomarkers that are potentially involved in the development of CSVD. In this present study, we aimed to investigate the relationship between candidate molecules and CSVD features.

METHOD

The concentration of each biomarker was measured in 79 acute ischemic stroke patients admitted within 72 h after symptom onset. The associations between blood levels of inflammatory markers and CSVD score were investigated, as well as each CSVD feature, including white matter hyperintensities (WMH), lacunes, and enlarged perivascular spaces (EPVS).

RESULTS

The mean age was 69.0 ± 11.8 years, and 65.8% of participants were male. Higher SERPINA3 level (>78.90 ng/mL) was significantly associated with larger WMH volume and higher scores on Fazekas's scale in all three models. Multiple regression analyses revealed the linear association between absolute WMH burden and SERPINA3 level, especially in model 3 (β = 0.14; 95% confidence interval [CI], 0.04-0.24; p = 0.008 ). Restricted cubic spline regression demonstrated a dose-response relationship between SERPINA3 level and larger WMH volume (p nonlineariy = 0.0366 and 0.0378 in model 2 and mode 3, respectively). Using a receiving operating characteristic (ROC) curve, plasma SERPINA3 level of 64.15 ng/mL distinguished WMH >7.8 mL with the highest sensitivity and specificity (75.92% and 60%, respectively, area under curve [AUC] = 0.668, p = 0.0102). No statistically significant relationship has been found between other candidate biomarkers and CSVD features.

CONCLUSION

In summary, among four inflammatory biomarkers that we investigated, SERPINA3 level at baseline was associated with WMH severity, which revealed a novel biomarker for CSVD and validated its relationship with inflammation and endothelial dysfunction.

Influence of threshold selection and image sequence in in-vivo segmentation of enlarged perivascular spaces

BACKGROUND

Growing interest surrounds perivascular spaces (PVS) as a clinical biomarker of brain dysfunction given their association with cerebrovascular risk factors and disease. Neuroimaging techniques allowing quick and reliable quantification are being developed, but, in practice, they require optimisation as their limits of validity are usually unspecified.

NEW METHOD

We evaluate modifications and alternatives to a state-of-the-art (SOTA) PVS segmentation method that uses a vesselness filter to enhance PVS discrimination, followed by thresholding of its response, applied to brain magnetic resonance images (MRI) from patients with sporadic small vessel disease acquired at 3 T.

RESULTS

The method is robust against inter-observer differences in threshold selection, but separate thresholds for each region of interest (i.e., basal ganglia, centrum semiovale, and midbrain) are required. Noise needs to be assessed prior to selecting these thresholds, as effect of noise and imaging artefacts can be mitigated with a careful optimisation of these thresholds. PVS segmentation from T1-weighted images alone, misses small PVS, therefore, underestimates PVS count, may overestimate individual PVS volume especially in the basal ganglia, and is susceptible to the inclusion of calcified vessels and mineral deposits. Visual analyses indicated the incomplete and fragmented detection of long and thin PVS as the primary cause of errors, with the Frangi filter coping better than the Jerman filter.

COMPARISON WITH EXISTING METHODS

Limits of validity to a SOTA PVS segmentation method applied to 3 T MRI with confounding pathology are given.

CONCLUSIONS

Evidence presented reinforces the STRIVE-2 recommendation of using T2-weighted images for PVS assessment wherever possible. The Frangi filter is recommended for PVS segmentation from MRI, offering robust output against variations in threshold selection and pathology presentation.

Contributions of amyloid beta and cerebral small vessel disease in clinical decline

INTRODUCTION

We assessed whether co-morbid small vessel disease (SVD) has clinical predictive value in preclinical or prodromal Alzheimer's disease.

METHODS

In 1090 non-demented participants (65.4 ± 10.7 years) SVD was assessed with magnetic resonance imaging and amyloid beta (Aβ) with lumbar puncture and/or positron emission tomography scan (mean follow-up for cognitive function 3.1 ± 2.4 years).

RESULTS

Thirty-nine percent had neither Aβ nor SVD (A-V-), 21% had SVD only (A-V+), 23% Aβ only (A+V-), and 17% had both (A+V+). Pooled cohort linear mixed model analyses demonstrated that compared to A-V- (reference), A+V- had a faster rate of cognitive decline. Co-morbid SVD (A+V+) did not further increase rate of decline. Cox regression showed that dementia risk was modestly increased in A-V+ (hazard ratio [95% confidence interval: 1.8 [1.0-3.2]) and most strongly in A+ groups. Also, mortality risk was increased in A+ groups.

DISCUSSION

In non-demented persons Aβ was predictive of cognitive decline, dementia, and mortality. SVD modestly predicts dementia in A-, but did not increase deleterious effects in A+.

HIGHLIGHTS

Amyloid beta (Aβ; A) was predictive for cognitive decline, dementia, and mortality. Small vessel disease (SVD) had no additional deleterious effects in A+. SVD modestly predicted dementia in A-. Aβ should be assessed even when magnetic resonance imaging indicates vascular cognitive impairment.

Impact of cerebral small vessel disease burden and drug level at admission on direct oral anticoagulant associated intracerebral hemorrhage

INTRODUCTION

Direct oral anticoagulant (DOAC)-associated intracerebral hemorrhage (ICH) is a catastrophic complication. The aim of this study was to investigate the association between computed tomography (CT)-based cerebrovascular small vessel disease (SVD) burden and DOAC-ICH as well as the DOAC concentration upon hospital admission and ICH outcome.

PATIENTS AND METHODS

The study included two cohorts: (1) DOAC-ICH: patients who suffered from DOAC-ICH and underwent drug level measurements upon admission; (2) DOAC-non-ICH: stable DOAC users who underwent head CT without ICH during treatment. We categorized the DOAC levels of the DOAC-ICH patients as low (<50 ng/mL), medium (50-300 ng/mL), and high (>300 ng/mL). The CT-based SVD burden (including white matter lesions [WML], lacunes, and cerebral atrophy) was evaluated, and SVD scores (range, 0-3) were used to evaluate SVD severity.

RESULTS

A total of 43 DOAC-ICH patients and 177 DOAC-non-ICH patients were enrolled. DOAC-ICH patients were more likely to have WML, lacunes, or cerebral atrophy compared to DOAC-non-ICH patients. After adjustment, the SVD burden was associated with DOAC-ICH, with a higher risk of more severe SVD (SVD score of 2; odds ratio [OR], 10.3 [3.17, 33.3]; score of 3; OR, 16.8 [4.50, 62.6]). The proportions of patients with high, medium, and low drug levels in the DOAC-ICH group were 16.3%, 55.8%, and 27.9%, respectively. Additionally, the high-level group displayed a larger hematoma size and had worse functional outcomes at 3 months than the other two groups.

DISCUSSION AND CONCLUSION

The severity of SVD burden was associated with DOAC-ICH. Furthermore, high DOAC levels in ICH were associated with unfavorable clinical outcomes. To address the potential selection bias from these two cohorts, a prospective study to investigate the co-contribution of drug levels and SVD to DOAC-ICH is essential.

The glymphatic system and cerebral small vessel disease

OBJECTIVES

Cerebral small vessel disease is a group of pathologies in which alterations of the brain's blood vessels contribute to stroke and neurocognitive changes. Recently, a neurotoxic waste clearance system composed of perivascular spaces abutting the brain's blood vessels, termed the glymphatic system, has been identified as a key player in brain homeostasis. Given that small vessel disease and the glymphatic system share anatomical structures, this review aims to reexamine small vessel disease in the context of the glymphatic system and highlight novel aspects of small vessel disease physiology.

MATERIALS AND METHODS

This review was conducted with an emphasis on studies that examined aspects of small vessel disease and on works characterizing the glymphatic system. We searched PubMed for relevant articles using the following keywords: glymphatics, cerebral small vessel disease, arterial pulsatility, hypertension, blood-brain barrier, endothelial dysfunction, stroke, diabetes.

RESULTS

Cerebral small vessel disease and glymphatic dysfunction are anatomically connected and significant risk factors are shared between the two. These include hypertension, type 2 diabetes, advanced age, poor sleep, obesity, and neuroinflammation. There is clear evidence that CSVD hinders the effective functioning of glymphatic system.

CONCLUSION

These shared risk factors, as well as the model of cerebral amyloid angiopathy pathogenesis, hint at the possibility that glymphatic dysfunction could independently contribute to the pathogenesis of cerebral small vessel disease. However, the current evidence supports a model of cascading dysfunction, wherein concurrent small vessel and glymphatic injury hinder glymphatic-mediated recovery and promote the progression of subclinical to clinical disease.

Hemodynamic significance of intracranial atherosclerotic disease and ipsilateral imaging markers of cerebral small vessel disease

INTRODUCTION

Cerebral small vessel disease (CSVD) commonly exists in patients with symptomatic intracranial atherosclerotic disease (sICAD). We aimed to investigate the associations of hemodynamic features of sICAD lesions with imaging markers and overall burden of CSVD.

PATIENTS AND METHODS

Patients with anterior-circulation sICAD (50%-99% stenosis) were analyzed in this cross-sectional study. Hemodynamic features of a sICAD lesion were quantified by translesional pressure ratio (PR = Pressurepost-stenotic/Pressurepre-stenotic) and wall shear stress ratio (WSSR = WSSstenotic-throat/WSSpre-stenotic) via CT angiography-based computational fluid dynamics modeling. PR ⩽median was defined as low ("abnormal") PR, and WSSR ⩾ fourth quartile as high ("abnormal") WSSR. For primary analyses, white matter hyperintensities (WMHs), lacunes, and cortical microinfarcts (CMIs) were assessed in MRI and summed up as overall CSVD burden, respectively in ipsilateral and contralateral hemispheres to sICAD. Enlarged perivascular spaces (EPVSs) and cerebral microbleeds (CMBs) were assessed for secondary analyses.

RESULTS

Among 112 sICAD patients, there were more severe WMHs, more lacunes and CMIs, and more severe overall CSVD burden ipsilaterally than contralaterally (all p < 0.05). Abnormal PR and WSSR (vs normal PR and WSSR) was significantly associated with moderate-to-severe WMHs (adjusted odds ratio = 10.12, p = 0.018), CMI presence (5.25, p = 0.003), and moderate-to-severe CSVD burden (12.55; p = 0.033), ipsilaterally, respectively independent of contralateral WMHs, CMI(s), and CSVD burden. EPVSs and CMBs were comparable between the two hemispheres, with no association found with the hemodynamic metrics.

DISCUSSION AND CONCLUSION

There are more severe WMHs and CMI(s) in the hemisphere ipsilateral than contralateral to sICAD. The hemodynamic significance of sICAD lesions was independently associated with severities of WMHs and CMI(s) ipsilaterally.

Modified Magnetic Resonance Imaging Burden of Cerebral Small Vessel Disease and Related Risk Factors in Patients With Thalassemia

OBJECTIVE

This study aimed to explore the burden of magnetic resonance imaging (MRI) of cerebral small vessel disease (CSVD) in patients with thalassemia and related risk factors.

METHODS

The clinical data and MRI of patients with thalassemia were retrospectively analyzed, and non-thalassemia controls with matched sex and age were selected. The modified MRI burden of CSVD included recent small subcortical infarct, presumed vasogenic white matter hyperintensity, presumed vasogenic lacunae, perivascular space (PVS), and brain atrophy.

RESULTS

This study included 110 patients in each of the thalassemia and control groups. There was no significant difference in sex, age, and common cerebrovascular disease risk factors between the 2 groups. The patients with thalassemia had a higher red blood cell count and lower content of hemoglobin. The PVS and modified MRI burden scores in the thalassemia group were higher than in the control group. With the increase in age, patients with thalassemia have a more severe CSVD burden.

CONCLUSION

Patients with thalassemia have a heavier modified MRI burden of CSVD than non-thalassemia patients, particularly PVS, and aging is an important risk factor for CSVD changes.

Immune regulation and blood-brain barrier permeability in cerebral small vessel disease: study protocol of the INflammation and Small Vessel Disease (INSVD) study - a multicentre prospective cohort study

INTRODUCTION

The INflammation and Small Vessel Disease (INSVD) study aims to investigate whether peripheral inflammation, immune (dys)regulation and blood-brain barrier (BBB) permeability relate to disease progression in cerebral small vessel disease (SVD). This research aims to pinpoint specific components of the immune response in SVD relating to disease progression. This could identify biomarkers of SVD progression, as well as potential therapeutic targets to inform the development and repurposing of drugs to reduce or prevent SVD, cognitive decline and vascular dementia.

METHODS AND ANALYSIS

INSVD is a prospective observational multicentre cohort study in individuals with symptomatic SVD. This longitudinal study combines comprehensive immunophenotyping of the peripheral blood immune compartment with advanced neuroimaging markers of SVD and BBB permeability. The main SVD marker of interest is white matter microstructure as determined by diffusion tensor imaging, a valuable marker of disease progression owing to its sensitivity to early alterations to white matter integrity. The research is being conducted in two sites-in the UK (Cambridge) and the Netherlands (Nijmegen)-with each site recruiting 100 participants (total n=200). Participants undergo clinical and cognitive assessments, blood draws, and brain MRI at baseline and 2-year follow-up.

ETHICS AND DISSEMINATION

This study received ethical approval from the local ethics boards (UK: East of England-Cambridge Central Research Ethics Committee (REC) ref: 22/EE/00141, Integrated Research Application System (IRAS) ID: 312 747. Netherlands: Medical Research Ethics Committee (MREC) Oost-Nederland, ref: 2022-13623, NL-number: NL80258.091.22). Written informed consent was obtained from all subjects before the study. Any participant-derived benefits resulting from this research, such as new insights into disease mechanisms or possible novel therapies, will be disseminated to study participants, patient groups and members of the public.

TRIAL REGISTRATION NUMBER

NCT05746221.

Increased Extracellular Water in Normal-Appearing White Matter in Patients with Cerebral Small Vessel Disease

BACKGROUND

Microcirculatory variations have been observed in the normal-appearing white matter (NAWM) of individuals affected by cerebral small vessel disease (CSVD). These variations collectively possess the potential to trigger neuroinflammation and edema, ultimately leading to an elevation in extracellular fluid (ECF). Nevertheless, the specific alterations in ECF within the NAWM of CSVD patients have remained inadequately understood.

METHODS

We reviewed the clinical and imaging characteristics of a cohort comprising 129 patients diagnosed with CSVD to investigate alterations in the ECF within NAWM. The severity of CSVD was assessed by total CSVD magnetic resonance (MR) score according to the four imaging markers, namely perivascular space, lacunar infarction, white matter hyperintensities and cerebral microbleed. ECF was evaluated by the parameter free water (FW), ranging from 0 to 1 generated from diffusion tensor imaging.

RESULTS

Significant differences in NAWM FW were observed in relation to the total CSVD MR score (p < 0.05). Patients with a total CSVD MR score of 0 exhibited significantly lower NAWM free water (FW) values compared to those with a score greater than 0 (p < 0.05). Similarly, patients with a total CSVD MR score of 1 also demonstrated notably lower NAWM FW values than those with a score greater than 1 (p < 0.05). After conducting multivariate regression analysis, age and total CSVD MR score was independently associated with FW in NAWM (p < 0.001). Further, the total CSVD MR score served as a partial mediator in the relationship between age and FW in the NAWM among patients with CSVD.

CONCLUSIONS

ECF in NAWM is increased in CSVD patients, even during the early course of CSVD.

The relationship between amyloid pathology, cerebral small vessel disease, glymphatic dysfunction, and cognition: a study based on Alzheimer's disease continuum participants

BACKGROUND

Glymphatic dysfunction is a crucial pathway for dementia. Alzheimer's disease (AD) pathologies co-existing with cerebral small vessel disease (CSVD) is the most common pathogenesis for dementia. We hypothesize that AD pathologies and CSVD could be associated with glymphatic dysfunction, contributing to cognitive impairment.

METHOD

Participants completed with amyloid PET, diffusion tensor imaging (DTI), and T2 fluid-attenuated inversion-recovery (FLAIR) sequences were included from the Alzheimer's Disease Neuroimaging Initiative (ADNI). White matter hyperintensities (WMH), the most common CSVD marker, was evaluated from T2FLAIR images and represented the burden of CSVD. Amyloid PET was used to assess Aβ aggregation in the brain. We used diffusion tensor image analysis along the perivascular space (DTI-ALPS) index, the burden of enlarged perivascular spaces (PVS), and choroid plexus volume to reflect glymphatic function. The relationships between WMH burden/Aβ aggregation and these glymphatic markers as well as the correlations between glymphatic markers and cognitive function were investigated. Furthermore, we conducted mediation analyses to explore the potential mediating effects of glymphatic markers in the relationship between WMH burden/Aβ aggregation and cognition.

RESULTS

One hundred and thirty-three participants along the AD continuum were included, consisting of 40 CN - , 48 CN + , 26 MCI + , and 19 AD + participants. Our findings revealed that there were negative associations between whole-brain Aβ aggregation (r =  - 0.249, p = 0.022) and WMH burden (r =  - 0.458, p < 0.001) with DTI-ALPS. Additionally, Aβ aggregation (r = 0.223, p = 0.041) and WMH burden (r = 0.294, p = 0.006) were both positively associated with choroid plexus volume. However, we did not observe significant correlations with PVS enlargement severity. DTI-ALPS was positively associated with memory (r = 0.470, FDR-p < 0.001), executive function (r = 0.358, FDR-p = 0.001), visual-spatial (r = 0.223, FDR-p < 0.040), and language (r = 0.419, FDR-p < 0.001). Conversely, choroid plexus volume showed negative correlations with memory (r =  - 0.315, FDR-p = 0.007), executive function (r =  - 0.321, FDR-p = 0.007), visual-spatial (r =  - 0.233, FDR-p = 0.031), and language (r =  - 0.261, FDR-p = 0.021). There were no significant correlations between PVS enlargement severity and cognitive performance. In the mediation analysis, we found that DTI-ALPS acted as a mediator in the relationship between WMH burden/Aβ accumulation and memory and language performances.

CONCLUSION

Our study provided evidence that both AD pathology (Aβ) and CSVD were associated with glymphatic dysfunction, which is further related to cognitive impairment. These results may provide a theoretical basis for new targets for treating AD.

Handwriting Movement Abnormalities in Older Adults with Silent Cerebral Small Vessel Disease-A Preliminary Study

BACKGROUND

The features of cerebral small vessel disease (CSVD) range from occurrence of asymptomatic radiological markers to symptomatic characteristics that include cognitive deficits and gait decline. The aim of the present study was to examine whether handwriting movement is abnormal in older people with CSVD through handwriting and drawing tasks using digitized handwriting kinematic assessment technology.

METHODS

Older subjects (n = 60) were grouped according to Fazekas score, with 16 in the Severe CSVD group, 12 in the Non-severe group and 32 in the Healthy group. Kinematic data were recorded and analyzed during handwriting and drawing tasks: signature; writing of Chinese characters ("" and ""); and Archimedes' spiral drawing.

RESULTS

The Severe CSVD group showed lower velocity and higher tortuosity during signature writing, lower velocity of stroke #4 of "" and vertical size of "" than did the Non-severe and Healthy groups. Both Severe CSVD and Non-severe CSVD subjects displayed higher average normalized jerk than did the Healthy group. Partial correlation analysis adjusting for age, gender, education, and mini-mental state evaluation (MMSE) showed that CSVD burden was positively associated with tortuosity of signature and average normalized jerk of Archimedes' spiral, and was negatively associated with velocity of strokes #3 and #4 of "", as well as vertical size of "".

CONCLUSIONS

Older adults with CSVD showed abnormal handwriting movement. And the handwriting abnormalities captured by digitized handwriting analysis were correlated with CSVD severity in users of simplified Chinese characters.