Associations of carotid artery flow parameters with MRI markers of cerebral small vessel disease and patterns of brain atrophy

Associations between cerebral small vessel disease and reduced forced vital capacity and expiratory volume in a general healthy Swedish elder population study-Good Aging in Skåne

BackgroundCerebral small vessel disease (CSVD) is one of the most important causes of cognitive decline. Only a few previous studies have evaluated lung function measures in relation to brain neuropathological changes, and even less studies on specific lesions and areas that could shed light on mechanisms of CSVD.ObjectiveThe aim was to study the association between lung function and CSVD in the general elder population.Methods379 participants, aged 72-87 years from the general population study 'Good Aging in Skåne study (GÅS)'were investigated with a 3 T MRI brain examination and spirometry. Z-scores of FEV1 and FVC were calculated using the GLI 2012 equations. Age-adjusted associations between white matter hyperintensities (WMH), medial temporal lobe atrophy (MTA), lacunar infarction, cerebral atrophies and cerebral microbleeds and lung function were calculated and stratified for sex.ResultsDecreased FEV1 and FVC z-scores below ≤ -1.0 were both associated with increased risk of WMI and global cortical atrophy. Decreased FVC z-scores were also associated with MTA and lacunar infarction in women and precuneus atrophy in men. The associations for WMH, MTA and lacunar infarctions and higher STRIVE score were noted among women, but not among men. FEV1 z scores were not related to diabetes, coronary artery disease or stroke.ConclusionsLower lung function was associated to MRI markers of CSVD in this general healthy population, particularly with WMH, especially for women. Although possible shared risk factors exist between lung and heart disease, lung function should be recognized in future studies on CSVD.

Shear Wave Elastography for Carotid Artery Stiffness: Ready for Prime Time?

Carotid artery stiffness is associated with aging and atherosclerotic disease, leading to cerebrovascular events. Shear Wave Elastography (SWE) is a novel ultrasound technique offering a direct, quantitative assessment of the arterial wall elasticity. The aim of this study is to validate the technical feasibility of SWE in measuring carotid stiffness (CS). A literature search was performed across the PubMed and Scopus databases, with keywords including "carotid stiffness", "Shear Wave Elastography", "atherosclerosis", and "vascular elasticity". The findings reveal the potential of SWE in quantifying carotid Intima-Media Complex (IMC) stiffness, with implications for the early diagnosis of vascular disease, aiding in clinical decision making and prognostic assessment. Based on the findings of the literature search, a small pilot study was conducted involving 10 participants, using the Philips EPIQ Elite system for the SWE measurements. The technical analysis revealed optimizing the region of interest (ROI) size, probe positioning, and cine-loop analysis as crucial factors for obtaining accurate results. The results of the literature review and small pilot study demonstrate the potential of SWE as a non-invasive method for assessing carotid stiffness. Certain technical adjustments, such as smaller ROIs and careful probe placement, improved the accuracy and repeatability of carotid SWE measurements. Further studies are needed to assess and standardize carotid SWE across larger patient populations.

Cerebrovascular pulsatility indicates preoperative subcortical cognitive impairment and an increased risk for postoperative delirium in elderly patients undergoing elective spine surgery

Introduction

Advances in spine surgery enable safe interventions in elderly patients, but perioperative neurocognitive disorders (pNCD), such as post-operative delirium (POD) and cognitive dysfunction (POCD), remain a serious concern. Pre-operative cognitive impairment is a major risk factor for pNCD. Comprehensive pre-operative cognitive assessments are not feasible in clinical practice, making effective screening methods desirable. This study investigates whether pre-operative cerebrovascular duplex sonography can assess subcortical (vascular) cognitive impairment and the risk for POD.

Methods

This prospective single-center study recruited patients aged ≥60 years scheduled for elective spine surgery at a German university hospital. Patients underwent pre-operative assessments including cognitive abilities (CERAD test battery), structural MRI, and cerebrovascular duplex sonography. POD screening was conducted three times daily for at least 3 days. The primary hypothesis, that the mean pulsatility index (PI) of both internal carotid arteries (ICA) predicts POD risk, was tested using logistic regression. Secondary analyses examined the association between POD risk and ICA flow (time-averaged peak velocities, TAPV) and correlations with cognitive profiles and MRI characteristics.

Results

POD occurred in 22% of patients (n = 22/99) within three postoperative days. Patients with POD were significantly older (75.9 ± 5.4 vs. 70.0 ± 6.9 years, p < 0.01) but did not differ by gender (p = 0.51). ICA PI significantly predicted POD risk (OR = 5.46 [95%CI: 1.81-16.49], p = 0.003), which remained significant after adjustment for age and duration of surgery (ORadj = 6.38 [95% CI: 1.77-23.03], p = 0.005). TAPV did not inform the POD risk (p = 0.68). ICA PI Pre-operative cognitive scores were significantly associated with ICA PI (mean CERAD score: r = -0.32, p < 0.001). ICA PI was also significantly associated with total white matter lesion volume (τ = 0.19, p = 0.012) and periventricular white matter lesion volume (τ = 0.21, p = 0.007).

Discussion

This is the first study to demonstrate that cerebrovascular duplex sonography can assess the risk for POD in elderly spine surgery patients. Increased ICA PI may indicate subcortical impairment, larger white matter lesion load, and lower white matter volume, predisposing factors for POD. Pre-operative cerebrovascular duplex sonography of the ICA is widely available, easy-to-use, and efficient, offering a promising screening method for POD risk. Increased ICA PI could supplement established predictors like age to adjust surgical and peri-operative procedures to individual risk profiles.

Estimated Pulse-Wave Velocity and Magnetic Resonance Imaging Markers of Cerebral Small-Vessel Disease in the NOMAS

BACKGROUND

Pulse-wave velocity is a measure of arterial stiffness and a risk factor for cardiovascular disease. Recently, an estimated pulse-wave velocity (ePWV) was introduced that was predictive of increased risk of cardiovascular disease. Our objective was to determine whether ePWV was associated with cerebral small-vessel disease on magnetic resonance imaging.

METHODS AND RESULTS

We included 1257 participants from the NOMAS (Northern Manhattan Study). The ePWV values were calculated using a nonlinear function of age and mean arterial blood pressure. The association between ePWV and white matter hyperintensity volume was assessed. Modification by race and ethnicity was evaluated. Associations between ePWV and other cerebral small-vessel disease markers, covert brain infarcts, cerebral microbleeds, and enlarged perivascular spaces, were explored as secondary outcomes. Mean±SD age of the cohort was 64±8 years; 61% were women; 18% self-identified as non-Hispanic Black, 67% as Hispanic, and 15% as non-Hispanic White individuals. Mean±SD ePWV was 11±2 m/s in the total NOMAS population and was similar across race and ethnic groups. The ePWV was significantly associated with white matter hyperintensity volume (β=0.23 [95% CI, 0.20-0.26]) after adjustment. Race and ethnicity modified the association between ePWV and white matter hyperintensity volume, with stronger associations in Hispanic and non-Hispanic Black individuals. Significant associations were found between ePWV and covert brain infarcts, cerebral microbleeds, and perivascular spaces after adjustment.

CONCLUSIONS

The ePWV function may provide a vascular mechanism for deleterious cerebrovascular outcomes in individuals with cerebral small-vessel disease and is particularly apparent in the racial and ethnic minorities represented in the NOMAS cohort.

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.

Correlation between Carotid Blood Flow Velocity and Total Magnetic Resonance Imaging Burden of Cerebral Small Vessel Disease in Patients with Recent Small Subcortical Infarcts

BACKGROUND

The common and internal carotid arteries are the upstream vessels of the small cerebral vessels. The relationship between hemodynamic changes in the significant cervical vessels and cerebral small vessel disease (CSVD) remains uncertain. This research sought to analyze the correlation between carotid blood flow velocity and the total magnetic resonance imaging (MRI) burden of CSVD in patients with recent small subcortical infarcts (RSSIs).

METHODS

Data were gathered from individuals diagnosed with RSSIs admitted to Changzhou Second People's Hospital between January 2022 and June 2023. Brain MRI was performed on every patient to determine the overall MRI burden of CSVD, along with carotid duplex ultrasound to evaluate carotid blood flow velocity and pulsatility index (PI) of the common carotid (CCA) and internal carotid (ICA) arteries. The association between carotid blood flow velocity and the total MRI load of CSVD was examined using univariate and multivariate analyses.

RESULTS

For our investigation, 272 individuals with RSSIs were screened. 82 individuals had a moderate to severe load of CSVD, while 190 participants showed a mild burden. Patients with moderate to severe burden of CSVD had lower end-diastolic velocity (EDV) and higher PI in CCA and ICA than those with mild load (P < 0.001). After adjusting for variables like age, hypertension, systolic blood pressure, and blood homocysteine levels, multivariate logistic regression analysis showed that EDV in CCA (OR, 0.894; P = 0.011), PI in CCA (OR, 5.869; P = 0.017), EDV in ICA (OR, 0.909; P = 0.008), and PI in ICA (OR, 5.324; P = 0.041) were independently related to moderate to severe CSVD burden. Spearman correlation analysis showed that EDV in CCA and ICA was negatively related to the total MRI load of CSVD in patients with RSSIs (P < 0.001). PI in CCA and ICA was positively associated with the whole MRI load of CSVD (P < 0.001).

CONCLUSION

Low carotid blood flow velocity and high carotid pulsatility index are independently associated with moderate to severe burden of CSVD.

Effects of Aerobic vs. Resistance Exercise on Vascular Function and Vascular Endothelial Growth Factor in Older Women

This study aimed to investigate the effects of different types of exercise (aerobic vs. resistance) on vascular function and vascular endothelial growth factor in older women. Forty-three older women, aged 65-75 years old, voluntarily participated in this study. All participants were randomly assigned to one of the following three groups: aerobic exercise (AE; n = 14), resistance exercise (RE; n = 15), and control (CG; n = 14) groups. All participants in the exercise groups performed their respective exercises for 60 min/day, three days/week, for 16 weeks. The intensity of aerobic and resistance exercises was determined using the individual heart rate reserve (40-60%) and RPE (12-13), respectively. The vascular function test included the brachial-ankle pulse wave velocity (ba-PWV), carotid artery blood flow volume, and velocity. Participants' blood samples were collected to analyze the vascular endothelial growth factor (VEGF). A significance level of 0.05 was set. Our results showed that ba-PWV improved following both AE (14.5%) and RE groups (11.1%) (all p < 0.05). Increases in carotid blood flow volume (AE: 15.4%, RE: 18.6%) and total artery peak velocity (AE: 20.4%, RE: 17%) were observed in AE and RE groups (p < 0.05), while flow total artery mean velocity (36.2%) and peak velocities (20.5%) were only increased in the aerobic exercise group (p < 0.05). VEGF was increased after resistance exercise (p < 0.05). Overall, aerobic exercise provides greater benefits on vascular function than resistance exercise but further research is needed on VEGF regarding whether this change is associated with vascular function improvement in older women.