White matter hyperintensity volume is increased in small vessel stroke subtypes

Effect of pre-stroke antiplatelet use on stroke outcomes in acute small vessel occlusion stroke with moderate to severe white matter burden

BACKGROUND

Cerebral small vessel disease is characterized by white matter hyperintensities (WMH) and acute small vessel occlusion (SVO) stroke. We investigated the effect of prior antiplatelet use (APU) on stroke outcome in 1151 patients with acute SVO stroke patients and moderate to severe WMH.

METHODS

Using a multicenter database, this retrospective study used quantitative WMH volume measurements and propensity score matching (PSM) for comparisons between patients with prior APU and without APU. Primary outcomes were stroke progression and poor functional outcome (modified Rankin Scale>2) at 3 months. Logistic regression analyses assessed associations between prior APU, WMH burden, and stroke outcomes.

RESULTS

Stroke progression was lower in the prior APU group in both the total cohort (14.8% vs. 6.9%, p < 0.001) and the PSM cohort (16.3% vs. 6.9%, p < 0.001). The proportion of poor functional outcomes at 3 months was not significantly different in the total cohort, but the PSM cohort showed a lower proportion in the prior APU group (30.8% vs. 20.2%, p = 0.002). Logistic regression analysis confirmed that prior APU was associated with a reduced risk of stroke progression (OR, 0.39; 95% CI, 0.22-0.70; p = 0.001) and poor functional outcome at 3 months (OR, 0.37; 95% CI, 0.23-0.59; p < 0.001).

CONCLUSION

Prior APU is associated with reduced stroke progression and improved functional outcome at 3 months in acute SVO stroke patients with moderate to severe WMH. Early treatment of WMH and acute SVO stroke may have potential benefits in improving stroke outcomes.

Trimethylamine N-Oxide and White Matter Hyperintensity Volume Among Patients With Acute Ischemic Stroke

Importance

Although increasing evidence suggests that trimethylamine N-oxide (TMAO) is associated with atherosclerosis, little is known about whether TMAO and its related metabolites (ie, choline, betaine, and carnitine) are associated with small vessel disease.

Objective

To evaluate the association between TMAO and its related metabolites with features of cerebral small vessel disease, including white matter hyperintensity volume (WMHV) and acute lacunar infarction.

Design, Setting, and Participants

This cross-sectional study included patients enrolled in the Specialized Programs of Translational Research in Acute Stroke biorepository. The registry included 522 patients with acute ischemic stroke who were 18 years or older who presented at the Massachusetts General Hospital or Brigham and Women's Hospital within 9 hours after onset between January 2007 and April 2010. The analyses in this study were conducted between November 2022 and April 2023.

Exposures

Plasma TMAO, choline, betaine, and carnitine were measured by liquid chromatography-tandem mass spectrometry.

Main Outcomes and Measures

WMHV was quantified by a semiautomated approach using signal intensity threshold with subsequent manual editing. Ischemic stroke subtype was classified using the Causative Classification System.

Results

Among 351 patients included in this study, the mean (SD) age was 69 (15) years; 209 patients (59.5%) were male and had a median (IQR) admission National Institute of Health Stroke Scale of 6 (3-13). The magnetic resonance imaging subgroup consisted of 291 patients with a mean (SD) age of 67 (15) years. Among these, the median (IQR) WMHV was 3.2 (1.31-8.4) cm3. TMAO was associated with WMHV after adjustment for age and sex (β, 0.15; 95% CI, 0.01-0.29; P < .001). TMAO remained significant in a multivariate analysis adjusted for age, sex, hypertension, diabetes, and smoking (β, 0.14; 95% CI, 0-0.29; P = .05). TMAO was associated with lacunar stroke but not other ischemic stroke subtypes in a model adjusted for age, sex, hypertension, diabetes, and smoking (OR, 1.67; 95% CI, 1.05-2.66; P = .03).

Conclusions and Relevance

In this observational study, TMAO was associated with cerebral small vessel disease determined by WMHV and acute lacunar infarction. The association was independent of traditional vascular risk factors.

Analysis of Risk Factors for White Matter Hyperintensity in Older Adults without Stroke

BACKGROUND

White matter hyperintensity (WMH) is prevalent in older adults aged 60 and above. A large proportion of people with WMH have not experienced stroke and little has been reported in the literature.

METHODS

The case data of patients aged ≥60 years without stroke in Wuhan Tongji Hospital from January 2015 to December 2019 were retrospectively analyzed. It was a cross-sectional study. Univariate analysis and logistic regression were used to analyze independent risk factors for WMH. The severity of WMH was assessed using the Fazekas scores. The participants with WMH were divided into periventricular white matter hyperintensity (PWMH) group and deep white matter hyperintensity (DWMH) group, then the risk factors of WMH severity were explored separately.

RESULTS

Eventually, 655 patients were included; among the patients, 574 (87.6%) were diagnosed with WMH. Binary logistic regression showed that age and hypertension were associated with the prevalence of WMH. Ordinal logistic regression showed that age, homocysteine, and proteinuria were associated with the severity of WMH. Age and proteinuria were associated with the severity of PWMH. Age and proteinuria were associated with the severity of DWMH.

CONCLUSIONS

The present study showed that in patients aged ≥60 years without stroke, age and hypertension were independent risk factors for the prevalence of WMH; while the increasing of age, homocysteine, and proteinuria were associated with greater WMH burden.

Association between Serum Amyloid A Level and White Matter Hyperintensity Burden: a Cross-Sectional Analysis in Patients with Acute Ischemic Stroke

INTRODUCTION

This work aimed to determine the potential link between white matter hyperintensity (WMH) burden and serum amyloid A (SAA) level in patients with acute ischemic stroke.

METHODS

Consecutive patients with acute large artery atherosclerosis (LAA) stroke between April 2021 and May 2022 were included. WMH volumes (periventricular, deep, and total) were measured using the Fazekas score and a semiautomated volumetric analysis on fluid-attenuated inversion recovery-magnetic resonance imaging. The burdens of WMH were scored to assess the dose-dependent association between SAA and WMH volume. Multivariate regression and a two-piecewise linear regression model were used to evaluate whether SAA levels are an independent predictor of WMH, and to discover the threshold effect or saturation effect of SAA levels with respect to WMH volume.

RESULTS

The mean age of patients was 63.2 ± 11.5 years, with 65.9% men. The median SAA level was 3.93 mg/L and the total WMH volume of 6.86 cm³. In the multivariable analysis, SAA remained an independent predictor of total WMH volume [β = 0.82, 95% confidence interval (CI) = 0.49-1.07, p < 0.001], periventricular WMH volume (adjusted β = 0.76, 95% CI = 0.46-1.07, p < 0.001), and deep WMH volume (adjusted β = 0.26, 95% CI = 0.06-0.45, p = 0.011) after controlling for confounders. Furthermore, SAA levels were associated with periventricular Fazekas score, deep Fazekas score, and Fazekas grades. Threshold effect and saturation effect analyses demonstrated a nonlinear relationship between SAA levels and periventricular white matter hyperintensity (PVWMH) volumes, with SAA levels (2.12-19.89 mg/L) having significant dose-dependent relationships with periventricular WMH volumes (adjusted β = 1.98, 95% CI = 1.12-2.84, p < 0.001).

CONCLUSION

SAA level ranging from 2.12 to 19.89 mg/L is dose-dependently associated with periventricular WMH development. These findings point the way forward for future research into the pathophysiology of WMH.

Systematic Mendelian randomization using the human plasma proteome to discover potential therapeutic targets for stroke

Stroke is the second leading cause of death with substantial unmet therapeutic needs. To identify potential stroke therapeutic targets, we estimate the causal effects of 308 plasma proteins on stroke outcomes in a two-sample Mendelian randomization framework and assess mediation effects by stroke risk factors. We find associations between genetically predicted plasma levels of six proteins and stroke (P ≤ 1.62 × 10-4). The genetic associations with stroke colocalize (Posterior Probability >0.7) with the genetic associations of four proteins (TFPI, TMPRSS5, CD6, CD40). Mendelian randomization supports atrial fibrillation, body mass index, smoking, blood pressure, white matter hyperintensities and type 2 diabetes as stroke risk factors (P ≤ 0.0071). Body mass index, white matter hyperintensity and atrial fibrillation appear to mediate the TFPI, IL6RA, TMPRSS5 associations with stroke. Furthermore, thirty-six proteins are associated with one or more of these risk factors using Mendelian randomization. Our results highlight causal pathways and potential therapeutic targets for stroke.

Association between white matter hyperintensity volume and social functioning limitations among stroke survivors

OBJECTIVE

Existing literature on white matter hyperintensity volume (WMHV) in stroke patients has rarely focused on post-stroke outcomes related to social functioning limitations, such as transportation, social interaction, food preparation, grocery shopping, and housekeeping. Using prospective data from the VITamin D and OmegA-3 TriaL (VITAL) study, we evaluated the association between WMHV and social functioning limitations among 151 ischemic stroke patients.

MATERIALS AND METHODS

WMHV was ascertained from magnetic resonance imaging (MRI) collected at the time of the stroke event using a validated semiautomated method, and social functioning limitations were assessed using a stroke outcomes questionnaire administered a median of 1.25 years after the date of the MRI scan. Logistic regression was used to explore the association between WMHV and social functioning limitations.

RESULTS

After adjusting for age and sex, a statistically significant association was found between WMHV and limitations in social interaction (OR=2.82; 95% CI: 1.21-7.55). Increased risks were seen for limitations related to food preparation (OR=2.06; 95% CI: 0.99-4.54), transportation (OR=1.39; 95% CI: 0.85-2.27), and housekeeping (OR=1.37; 95% CI: 0.91-2.11); however, the associations did not reach statistical significance. We observed no association between WMHV and limitations in grocery shopping (OR=1.08; 95% CI: 0.61-1.89).

CONCLUSIONS

Future studies are needed to further explore the biological mechanisms underlying the relationship with limitations in social interaction and to replicate our findings using a larger and more diverse study sample.

Impact of White Matter Hyperintensity Burden on Outcome in Large-Vessel Occlusion Stroke

Background White matter hyperintensity (WMH) has been linked to poor clinical outcomes after acute ischemic stroke. Purpose To assess whether the WMH burden on pretreatment MRI scans is associated with an increased risk for symptomatic intracranial hemorrhage (sICH) or poor functional outcome in patients with acute ischemic stroke treated with endovascular thrombectomy (EVT). Materials and Methods In this retrospective study, consecutive patients treated with EVT for anterior circulation acute ischemic stroke at a comprehensive stroke center (where MRI was the first-line pretreatment imaging strategy; January 2015 to December 2017) were included and analyzed. WMH volumes were assessed with semiautomated volumetric analysis at fluid-attenuated inversion recovery MRI by readers who were blinded to clinical data. The associations of WMH burden with sICH and 3-month functional outcome (modified Rankin Scale [mRS] score) were assessed. Results A total of 366 patients were included (mean age, 69 years ± 19 [SD]; 188 women [51%]). Median total WMH volume was 3.61 cm³ (IQR, 1.10-10.83 cm³). Patients demonstrated higher mRS scores with increasing WMH volumes (odds ratio [OR], 1.020 [95% CI: 1.003, 1.037] per 1.0-cm³ increase for each mRS point increase; P = .018) after adjustment for patient and clinical variables. There were no significant associations between WMH severity and 90-day mortality (OR, 1.007 [95% CI: 0.990, 1.024]; P = .40) or the occurrence of sICH (OR, 1.001 [95% CI: 0.978, 1.024]; P = .94). Conclusion Higher white matter hyperintensity burden was associated with increased risk for poor 3-month functional outcome after endovascular thrombectomy for large-vessel occlusive stroke. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Mossa-Basha and Zhu in this issue.

White Matter Hyperintensity Burden and Collateral Circulation in Large Vessel Occlusion Stroke

BACKGROUND AND PURPOSE

White matter hyperintensity (WMH), a marker of chronic cerebral small vessel disease, might impact the recruitment of leptomeningeal collaterals. We aimed to assess whether the WMH burden is associated with collateral circulation in patients treated by endovascular thrombectomy for anterior circulation acute ischemic stroke.

METHODS

Consecutive acute ischemic stroke due to anterior circulation large vessel occlusion and treated with endovascular thrombectomy from January 2015 to December 2017 were included. WMH volumes (periventricular, deep, and total) were assessed by a semiautomated volumetric analysis on fluid-attenuated inversion recovery-magnetic resonance imaging. Collateral status was graded on baseline catheter angiography using the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology grading system (good when ≥3). We investigated associations of WMH burden with collateral status.

RESULTS

A total of 302 patients were included (mean age, 69.1±19.4 years; women, 55.6%). Poor collaterals were observed in 49.3% of patients. Median total WMH volume was 3.76 cm³ (interquartile range, 1.09-11.81 cm³). The regression analyses showed no apparent relationship between WMH burden and the collateral status measured at baseline angiography (adjusted odds ratio, 0.987 [95% CI, 0.971-1.003]; P=0.12).

CONCLUSIONS

WMH burden exhibits no overt association with collaterals in large vessel occlusive stroke.

Effects of cerebral small vessel disease on the outcomes in cryptogenic stroke with active cancer

Cerebral small vessel diseases (cSVDs) affect the prognosis of various types of ischemic stroke. Therefore, we evaluated the association between cSVD and the prognosis of cryptogenic stroke patients with active cancer. We enrolled patients diagnosed with cryptogenic stroke and active cancer from 2010 to 2016. Early neurological deterioration (END) was defined as a ≥ 2-point increase in the total NIHSS score or a ≥ 1-point increase in the motor NIHSS score within the first 72 h. We defined an unfavorable outcome as the modified Rankin Scale (mRS) score ≥ 3 points. We analyzed cSVD separately for each subtype including white matter hyperintensity (WMH), silent brain infarct (SBI), and cerebral microbleed (CMB). A total of 179 cryptogenic stroke patients with active cancer were evaluated. In the multivariable analysis, SBI was significantly associated with END (adjusted odds ratio = 3.97, 95% confidence interval: 1.53–10.33). This close relationship between SBI and END increased proportionally with an increase in SBI burden. However, WMH and CMB showed no significant association with END. None of the cSVD subtypes showed a statistically significant relationship with the 3-month unfavorable outcome. SBI was the only parameter closely associated with END in cryptogenic stroke patients with active cancer.

Obesity and Race May Explain Differential Burden of White Matter Hyperintensity Load

OBJECTIVE

Compared to European Americans, research indicates that African Americans have higher white matter hyperintensity (WMH) load; however, the clinical and biological bases underlying this higher burden are poorly understood. We hypothesize that obesity may explain differences in WMH between African and European Americans.

METHODS

Participants enrolled in longitudinal brain aging studies (n=292; 61% Female; 92% European American; mean age=69.6±7.7) completed evaluations including medical exams, neuroimaging, and sociodemographic surveys. Overweight/obese status defined as body mass index ≥30 kg/m2, and WMH load, captured by FLAIR images, as sum of deep and periventricular volumes, scored using the Fazekas scale (0-6), WMH≥4 considered high.

RESULTS

Logistic regression analyses, adjusted for age, sex, hypertension, and smoking history, indicated that age and interaction between race and obesity were significant predictors of WMH, demonstrating that obesity significantly moderated the relationship between race and WMH. Age independently increased the odds of high WMH by 16% (OR=1.16, 95% CI=1.09-1.23, p<0.001). Stratified analysis indicates that older European Americans had increased WMH (OR=1.17, 95% CI=1.09-1.23, p<0.001), while obese African Americans had increased WMH (OR=27.65, 95% CI=1.47-519.13, p<0.05). In a case controlled subgroup matched by age, sex, and education (n=48), African Americans had significantly higher WMH load (27% vs 4%, Χ 2=5.3, p=0.02).

CONCLUSION

Results denote that age predicted WMH among European Americans, while obesity predicted WMH among African Americans. Matched sample analyses indicate that obesity increases the odds of WMH, though more pronounced in African Americans. These findings suggest that obesity may explain the differential burden of white matter hyperintensity load, signifying public health and clinical importance.

Outcome after acute ischemic stroke is linked to sex-specific lesion patterns

Acute ischemic stroke affects men and women differently. In particular, women are often reported to experience higher acute stroke severity than men. We derived a low-dimensional representation of anatomical stroke lesions and designed a Bayesian hierarchical modeling framework tailored to estimate possible sex differences in lesion patterns linked to acute stroke severity (National Institute of Health Stroke Scale). This framework was developed in 555 patients (38% female). Findings were validated in an independent cohort (n = 503, 41% female). Here, we show brain lesions in regions subserving motor and language functions help explain stroke severity in both men and women, however more widespread lesion patterns are relevant in female patients. Higher stroke severity in women, but not men, is associated with left hemisphere lesions in the vicinity of the posterior circulation. Our results suggest there are sex-specific functional cerebral asymmetries that may be important for future investigations of sex-stratified approaches to management of acute ischemic stroke.

Intracranial Atherosclerotic Burden and Cerebral Parenchymal Changes at 7T MRI in Patients With Transient Ischemic Attack or Ischemic Stroke

The relevance of intracranial vessel wall lesions detected with MRI is not fully established. In this study (trial identification number: NTR2119; www.trialregister.nl), 7T MRI was used to investigate if a higher vessel wall lesion burden is associated with more cerebral parenchymal changes in patients with ischemic stroke or transient ischemic attack (TIA). MR images of 82 patients were assessed for the number of vessel wall lesions of the large intracranial arteries and for cerebral parenchymal changes, including the presence and number of cortical, small subcortical, and deep gray matter infarcts; lacunes of presumed vascular origin; cortical microinfarcts; and periventricular and deep white matter hyperintensities (WMHs). Regression analyses showed that a higher vessel wall lesion burden was associated with the presence of small subcortical infarcts, lacunes of presumed vascular origin, and deep gray matter infarcts (relative risk 1.18; 95% CI, 1.03–1.35) and presence of moderate-to-severe periventricular WMHs (1.21; 95% CI, 1.03–1.42), which are all manifestations of small vessel disease (SVD). The burden of enhancing vessel wall lesions was associated with the number of cortical microinfarcts only (1.48; 95% CI, 1.04–2.11). These results suggest an interrelationship between large vessel wall lesion burden and cerebral parenchymal manifestations often linked to SVD or, alternatively, that vascular changes occur in both large and small intracranial arteries simultaneously.

Increased tortuosity of bilateral distal internal carotid artery is associated with white matter hyperintensities

BACKGROUND

Although the pathophysiology of white matter hyperintensities remains unclear, we can recently explore the possible relationship with white matter hyperintensities by using quantitative parameter.

PURPOSE

To demonstrate the relationship between bilateral distal internal carotid arterial tortuosity and total brain white matter hyperintensities volume in elderly individuals.

MATERIAL AND METHODS

A total of 345 patients (age > 65 years) with brain magnetic resonance (MR) examinations were retrospectively included (44.1% men; mean age = 72.1 ± 6.25 years; 55.9% ≥ 70 years). We measured the Tortuosity Index (TI) of the bilateral distal internal carotid artery and basilar artery on MR angiography imaging, and white matter hyperintensities volume on fluid-attenuated inversion recovery MR sequence. Multiple linear regression was used to assess the association of the TI with quantitatively derived brain white matter hyperintensity volume, after adjusting for demographics (age, sex), vascular risk factors (hypertension, diabetes, heart disease), and vessel diameters, total intracranial volume (TIV).

RESULTS

Increased tortuosity of bilateral distal internal carotid artery was associated with greater burden of white matter hyperintensity volume (right: β = 11.223, P = 0.016; left: β = 20.701, P < 0.001). This relationship was independent of age and hypertension, both of which have been considered the strongest risk factors for white matter hyperintensities.

CONCLUSION

Our results suggest that tortuosity of the bilateral distal internal carotid artery is associated with white matter hyperintensities, independent of age and hypertension.

Association of White Matter Hyperintensity Markers on MRI and Long-term Risk of Mortality and Ischemic Stroke: The SMART-MR Study

OBJECTIVE

To determine whether white matter hyperintensity (WMH) markers on MRI are associated with long-term risk of mortality and ischemic stroke.

METHODS

We included consecutive patients with manifest arterial disease enrolled in the Second Manifestations of Arterial Disease-Magnetic Resonance (SMART-MR) study. We obtained WMH markers (volume, type, and shape) from brain MRI scans performed at baseline using an automated algorithm. During follow-up, occurrence of death and ischemic stroke was recorded. Using Cox regression, we investigated associations of WMH markers with risk of mortality and ischemic stroke, adjusting for demographics, cardiovascular risk factors, and cerebrovascular disease.

RESULTS

We included 999 patients (59 ± 10 years; 79% male) with a median follow-up of 12.5 years (range 0.2-16.0 years). A greater periventricular or confluent WMH volume was independently associated with a greater risk of vascular death (hazard ratio [HR] 1.29, 95% confidence interval [CI] 1.13-1.47) for a 1-unit increase in natural log-transformed WMH volume and ischemic stroke (HR 1.53, 95% CI 1.26-1.86). A confluent WMH type was independently associated with a greater risk of vascular (HR 1.89, 95% CI 1.15-3.11) and nonvascular death (HR 1.65, 95% CI 1.01-2.73) and ischemic stroke (HR 2.83, 95% CI 1.36-5.87). A more irregular shape of periventricular or confluent WMH, as expressed by an increase in concavity index, was independently associated with a greater risk of vascular (HR 1.20, 95% CI 1.05-1.38 per SD increase) and nonvascular death (HR 1.21, 95% CI 1.03-1.42) and ischemic stroke (HR 1.28, 95% CI 1.05-1.55).

CONCLUSIONS

WMH volume, type, and shape are associated with long-term risk of mortality and ischemic stroke in patients with manifest arterial disease.

Elevated Circulating Microparticle Subpopulations in Incidental Cerebral White Matter Hyperintensities: A Multimodal Study

Asymptomatic (or "silent") manifestations of cerebral small vessel disease (CSVD) are widely recognized through incidental findings of white matter hyperintensities (WMHs) as a result of magnetic resonance imaging (MRI). This study aims to examine the potential associations of surrogate markers for the evaluation of white matter integrity in CSVD among asymptomatic individuals through a battery of profiling involving QRISK2 cardiocerebrovascular risk prediction, neuroimaging, neurocognitive evaluation, and microparticles (MPs) titers. Sixty asymptomatic subjects (mean age: 39.83 ± 11.50 years) with low to moderate QRISK2 scores were recruited and underwent neurocognitive evaluation for memory and cognitive performance, peripheral venous blood collection for enumeration of selected MPs subpopulations, and 3T MRI brain scan with specific diffusion MRI (dMRI) sequences inclusive of diffusion tensor imaging (DTI). WMHs were detected in 20 subjects (33%). Older subjects (mean age: 46.00 ± 12.00 years) had higher WMHs prevalence, associated with higher QRISK2 score and reduced processing speed. They also had significantly higher mean percentage of platelet (CD62P)- and leukocyte (CD62L)-derived MPs. No association was found between reduced white matter integrity-especially at the left superior longitudinal fasciculus (LSLF)-with age and neurocognitive function; however, LSLF was associated with higher QRISK2 score, total MPs, and CD62L- and endothelial cell-derived MPs (CD146). Therefore, this study establishes these multimodal associations as potential surrogate markers for "silent" CSVD manifestations in the well-characterized cardiocerebrovascular demographic of relatively young, neurologically asymptomatic adults. Furthermore, to the best of our knowledge, this study is the first to exhibit elevated MP counts in asymptomatic CSVD (i.e., CD62P and CD62L), which warrants further delineation.

Systemic oxidative stress and cognitive function in Parkinson's disease with different PWMH or DWMH lesions

BACKGROUND

Parkinson's disease (PD), frequently accompanied by cognitive impairments, is associated with systemic oxidative stress and abnormal structural changes on brain images. We aimed to identify the correlation between systemic oxidative stress and cognitive function in PD patients with different periventricular white matter hyperintensities (PWMH) and deep white matter hyperintensities (DWMH).

METHODS

A total of 146 participants with idiopathic PD underwent brain MRI, which revealed PWMH and DWMH. The number of lesions were evaluated using the Fazekas criteria. Systemic oxidative stress was determined as early or late phase changes in leukocyte apoptosis and its subsets by flow cytometry. Cognitive functions, including attention, executive function, memory, language, and visual space, were assessed.

RESULTS

For different DWMH, the leukocyte apoptosis and its subsets were significantly different.. However, there were no significant differences in oxidative stress biomarkers in PD patients with different PWMH. Attention and memory were significantly decreased in patients with more advanced DWMH injuries. Attention, memory, and language were significantly impaired in patients with worse PWMH lesions.

CONCLUSION

Significant oxidative stress biomarker alternations in PD patients with DWMH, but not PWMH, might be associated with white matter injury. Systemic inflammatory responses may contribute to deep white matter damage in PD. Further, more cognitive deficits were seen in PD patients with worse deep white matter lesions, especially in moderate to severe periventricular white matter injury.

TRIAL REGISTRATION

Retrospective study.

Relevance of cerebral small vessel disease load scores in first-ever lacunar infarction

AIM

To reveal the correlation between total cerebrovascular disease load and primary lacunar infarction.

BACKGROUND

Cerebral small vessel disease (CSVD) is the lack of specific clinical manifestations, whose clinical diagnoses are highly dependent on neuroimaging results. Total CSVD load scores may be more suitable for the assessment of overall brain function damage caused by CSVD. Little is known about whether the association between imaging markers of CSVD and CSVD total load scores at the time of first-ever lacunar infarction (LI).

METHODS

clinical data of 396 patients hospitalised from September 2016 to May 2018 due to a first-ever LI (case group), along with patients diagnosed with CSVD based on imaging alone and those with no abnormalities (control group) based on magnetic resonance imaging (MRI). Binary logistic regression and multiple ordered logistic regression were used to analyse the characteristics of imaging markers of CSVD in patients with first-ever LI, including different total score burden and distribution, and the relationship between different markers.

RESULTS

In 396 patients, smoking, cholesterol level and total small vessel disease (SVD) score were all significantly associated with the first-ever LI. There were more LI, cerebral microbleeds (CMB), white matter hyperintensities (WMH), and moderate to severe enlarged perivascular spaces (EPVS) in the first-ever LI group, relative to controls (p < 0.01). The Fazekas scores for periventricular WMH, deep WMH, and total Fazekas score were all significantly higher in patients with first-ever LI relative to those with no cerebral abnormalities (p < 0.01). An analysis of various imaging markers of CSVD revealed a significant correlation between the presence and degree of any marker and the severity of other markers, even after adjusting for the presence of other markers (p < 0.05).

CONCLUSIONS

The first-ever LI group exhibited higher total CSVD score loads, a greater number of lacunae, CMB, severe WMH and moderate to severe EPVS. Smoking is an independent risk factor in patients with first-ever LI.

The relationship of leukoaraiosis, haemorrhagic transformation and prognosis at 3 months after intravenous thrombolysis in elderly patients aged ≥ 60 years with acute cerebral infarction

Backgroud

As the elderly stroke population continues to increase, we will have to confront greater challenges regarding how to choose suitable patients to reduce thrombolysis-related bleeding events and accurately judge their prognosis. Therefore, we evaluated the relationship among leukoaraiosis (LA), haemorrhagic transformation (HT) and the prognosis at 3 months after intravenous (IV) thrombolysis in elderly patients aged ≥ 60 years with acute cerebral infarction (ACI).

Methods

We prospectively and consecutively chose 125 elderly patients aged ≥ 60 years with ACI who could accept and be suitable for IV recombinant tissue plasminogen activator (rtPA) after excluding 6 cases. Brain computed tomography(CT) was used to assess LA by using the modified Van Swieten scale (mVSS) before treatment and the modified Rankin scale (mRS) to appraise prognosis at 3 months after IV rtPA. Binary logistic regression was used to analyse the predictors of HT and the prognosis of ACI.

Results

Our data indicated that by brain CT, 26.4% of all patients showed severe LA, and the rate of HT and symptomatic intracranial haemorrhage (sICH) were 12.0% and 9.6%, respectively. Severe LA was evidently associated with HT (odds ratio [OR] 3.272, 95% confidence interval [CI] 1.010–10.598, P = 0.048) rather sICH (P > 0.05). Moreover, we also found that severe LA was associated with poor functional prognosis (OR 5.266, 95% CI 1.592–17.419, P = 0.006).

Conclusion

Our results showed that LA was associated with HT and adverse clinical prognosis rather sICH after IV rtPA in elderly patients aged ≥60 years with ACI. Although LA may increase the risk of bleeding but not fatal haemorrhage after IV thrombolysis, therefore, we should actively select an appropriate elderly population for thrombolytic treatment and have reasonable judgments on the outcomes.

Prospectively Collected Cardiovascular Biomarkers and White Matter Hyperintensity Volume in Ischemic Stroke Patients

BACKGROUND

Few prospective cohort studies collect detailed information on stroke characteristics among individuals who experience ischemic stroke, including white matter hyperintensity volume, and thus cannot explore how prospectively collected biomarkers prior to the stroke influence white matter hyperintensity volume. We explored the association between a large panel of prospectively collected lipid and inflammatory biomarkers and white matter hyperintensity volume among participants in the Women's Health Study with incident ischemic stroke.

METHODS

Among Women's Health Study participants with first ischemic stroke who had baseline serum biomarkers and available magnetic resonance imaging, we measured white matter hyperintensity volume using a validated semi-automated method. Linear regression was used to explore the associations between biomarkers and log-transformed white matter hyperintensity volume.

RESULTS

After multivariate adjustment, a 1% increment in HbA1c% was associated with an increase in white matter hyperintensity volume (P value = .05). Evidence of a nonlinear association between high density lipoprotein cholesterol levels and ApoA1 levels with white matter hyperintensity volume was noted (P values for nonlinearity = .01 and .001, respectively). No other biomarkers were significantly associated with white matter hyperintensity volume.

CONCLUSIONS

Chronic hyperglycemia as evidenced by HbA1c levels measured years prior to stroke is associated with white matter hyperintensity volume at the time of stroke. Additional research is needed to explain why low levels of high density lipoprotein cholesterol levels and ApoA1 may be associated with similar white matter hyperintensity volume as high levels.

Reduced forced vital capacity is associated with cerebral small vessel disease burden in cognitively normal individuals

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Decreased FVC (% pred) was associated with increased cerebral small vessel disease burden even in cognitively normal subjects.

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This reduced lung function was related to low Mini-Mental Status Examination (MMSE) scores in cognitively normal subjects.

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Path analyses showed that white matter hyperintensities partially mediated the positive relationship between FVC (% pred) and MMSE score.

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There was no significant association between low FVC (% pred) and cortical thickness in cognitively normal subjects.

Background

Pulmonary dysfunction is associated with elevated risk of cognitive decline. However, the mechanism underlying this relationship has not been fully investigated. In this study, we investigate the relationships between pulmonary function, cerebral small vessel disease (CSVD) markers, cortical thickness, and the Mini-Mental Status Examination (MMSE) scores in cognitively normal individuals.

Methods

We used a cross-sectional study design. We identified 1924 patients who underwent pulmonary function testing, three-dimensional brain magnetic resonance imaging (MRI), and the MMSE. Pulmonary function was analyzed according to the quintiles of percentage predicted values (% pred) for forced vital capacity (FVC) or forced expiratory volume in 1 s (FEV₁). Regarding CSVD markers, we visually rated white matter hyperintensities (WMH) and manually counted lacunes and microbleeds. Cortical thickness was measured by surface-based methods.

Results

Compared with the highest quintile of FVC, the lowest quintile of FVC (% pred) showed a higher risk of WMH (OR 1.98, 95% CI: 1.21–3.24) and lacunes (OR 1.86, 95% CI: 1.12–3.08). There were no associations between FVC or FEV₁ and cortical thickness. Low FVC, but not FEV₁, was associated with low MMSE scores. Path analyses showed that WMH partially mediated the positive relationship between FVC (% pred) and MMSE score.

Conclusions

Our findings suggested that decreased pulmonary function was associated with increased CSVD burdens, which in turn wass associated with decreased cognition, even in cognitively normal subjects.

The association between lacunes and white matter hyperintensity features on MRI: The SMART-MR study

Lacunes and white matter hyperintensities (WMHs) are features of cerebral small vessel disease (CSVD) that are associated with poor functional outcomes. However, how the two are related remains unclear. In this study, we examined the association between lacunes and several WMH features in patients with a history of vascular disease. A total of 999 patients (mean age 59 ± 10 years) with a 1.5 T brain magnetic resonance imaging (MRI) scan were included from the SMART-MR study. Lacunes were scored visually and WMH features (volume, subtype and shape) were automatically determined. Analyses consisted of linear and Poisson regression adjusted for age, sex, and total intracranial volume (ICV). Patients with lacunes (n = 188; 19%) had greater total (B = 1.03, 95% CI: 0.86 to 1.21), periventricular/confluent (B = 1.08, 95% CI: 0.89 to 1.27), and deep (B = 0.71, 95% CI: 0.44 to 0.97) natural log-transformed WMH volumes than patients without lacunes. Patients with lacunes had an increased risk of confluent type WMHs (RR = 2.41, 95% CI: 1.98 to 2.92) and deep WMHs (RR = 1.41, 95% CI: 1.22 to 1.62) and had a more irregular shape of confluent WMHs than patients without lacunes, independent of total WMH volume. In conclusion, we found that lacunes on MRI were associated with WMH features that correspond to more severe small vessel changes, mortality, and poor functional outcomes.

White matter hyperintensity burden in patients with ischemic stroke treated with thrombectomy

INTRODUCTION

To determine the influence of white matter hyperintensity (WMH) burden on functional outcome, rate of symptomatic intracerebral hemorrhage (sICH), and procedural success in patients with acute ischemic stroke (AIS) treated by mechanical thrombectomy (MT) with current stentriever/aspiration devices.

METHODS

Patients with AIS due to large vessel occlusion (LVO) from the Thrombectomie des Artères Cérébrales (THRACE) trial and prospective cohorts from 2 academic comprehensive stroke centers treated with MT were pooled and retrospectively analyzed. WMH volumes were obtained by semiautomated planimetric segmentation and tested in association with the rate of favorable outcome (90-day functional independence), substantial recanalization after MT, and sICH.

RESULTS

A total of 496 participants were included between 2015 and 2018 (50% female, mean age 68.1 ± 15.0 years). Overall, 434 (88%) patients presented with detectable WMH (mean ± SD 4.93 ± 7.7). Patients demonstrated increasingly worse outcomes with increasing WMH volumes (odds ratio [aOR]1.05 per 1-cm3 increase for unfavorable outcome, 95% confidence interval [CI] 1.01-1.06, p = 0.014). Fifty-seven percent of patients in the first quartile of WMH volume vs 28% in the fourth quartile demonstrated favorable outcome (p < 0.001). WMH severity was not associated with sICH rate (aOR 0.99, 95% CI 0.93-1.04, p = 0.66), nor did it influence recanalization success (aOR 0.99, 95% CI 0.96-1.02, p = 0.84).

CONCLUSION

Our study provides evidence that in patients with AIS due to LVO and high burden of WMH as assessed by pretreatment MRI, the safety and efficacy profiles of MT are similar to those in patients with lower WMH burden and confirms that they are at higher risk of unfavorable outcome. Because more than a quarter of patients in the highest WMH quartile experienced favorable 3 months outcome, WMH burden may not be a good argument to deny MT.

CLINICALTRIALSGOV IDENTIFIER

NCT01062698.

Patient-specific Conditional Joint Models of Shape, Image Features and Clinical Indicators

We propose and demonstrate a joint model of anatomical shapes, image features and clinical indicators for statistical shape modeling and medical image analysis. The key idea is to employ a copula model to separate the joint dependency structure from the marginal distributions of variables of interest. This separation provides flexibility on the assumptions made during the modeling process. The proposed method can handle binary, discrete, ordinal and continuous variables. We demonstrate a simple and efficient way to include binary, discrete and ordinal variables into the modeling. We build Bayesian conditional models based on observed partial clinical indicators, features or shape based on Gaussian processes capturing the dependency structure. We apply the proposed method on a stroke dataset to jointly model the shape of the lateral ventricles, the spatial distribution of the white matter hyperintensity associated with periventricular white matter disease, and clinical indicators. The proposed method yields interpretable joint models for data exploration and patient-specific statistical shape models for medical image analysis.

Exploring Cerebrovascular Function in Osteoarthritis: "Heads-up"

Individuals with osteoarthritis (OA) are at greater risk of cardiovascular and cerebrovascular incidents; yet, cerebrovascular control remains uncharacterized. Our primary outcome was to acquire cerebrovascular control metrics in patients with OA and compare measures to healthy control adults (CTL) without OA or cardiovascular complications. Our primary covariate was a 10-year risk factor for cardiovascular and stroke incidents, and secondary covariates were other cardiovascular disease risk factors (i.e., body mass index, carotid intima media thickness, and brachial flow-mediated dilation). Our secondary outcomes were to assess anatomical and functional changes that may be related to cerebrovascular reactivity were also acquired such as white matter lesion volume and brief cognitive assessments. In 25 adults (n = 13 CTL, n = 12 OA), under hypercapnia, magnetic resonance imaging (3T) was used to acquire a "Global Cerebrovascular Reactivity" index across the larger intracranial cerebral arteries and white matter lesions, and transcranial Doppler was used for both middle cerebral artery hemodynamic responses to hypercapnia and to assess autoregulation via a sit-to-stand task. Compared to CTL, OA had lower "Global Cerebrovascular Reactivity" index responses to hypercapnia, autoregulatory responses, and greater white matter lesions (P < 0.05). These differences persisted after covarying for the outlined primary and secondary covariates. Patients with OA, in the absence of known cardiovascular disease, can exhibit pre-clinical and impaired (compared to CTL) peripheral and cerebrovascular control metrics.

Minocycline reduces intracerebral hemorrhage-induced white matter injury in piglets

Aims

White matter (WM) injury after intracerebral hemorrhage (ICH) results in poor or even fatal outcomes. As an anti‐inflammatory drug, minocycline has been considered a promising choice to treat brain injury after ICH. However, whether minocycline can reduce WM injury after ICH is still controversial. In the present study, we investigate the effect and underlying mechanism of minocycline on WM injury after ICH.

Methods

An ICH model was induced by an injection of autologous blood into the right frontal lobe of piglets. First, transcriptional analysis was performed at day 1 or 3 to investigate the dynamic changes in neuroinflammatory gene expression in WM after ICH. Second, ICH piglets were treated either with minocycline or with vehicle alone. All piglets then underwent magnetic resonance imaging to measure brain swelling. Brain tissue was used for real‐time polymerase chain reaction (RT‐PCR), immunohistochemistry, Western blot, and electron microscopy.

Results

Transcriptional analysis demonstrated that transforming growth factor‐β (TGF‐β)/mitogen‐activated protein kinase (MAPK) signaling is associated with microglia/macrophage‐mediated inflammation activation after ICH and is then involved in WM injury after ICH in piglets. Minocycline treatment results in less ICH‐induced brain swelling, fewer neurological deficits, and less WM injury in comparison with the vehicle alone. In addition, minocycline reduces microglial activation and alleviates demyelination in white matter after ICH. Finally, we found that minocycline attenuates WM injury by increasing the expression of TGF‐β and suppressing MAPK activation after ICH.

Conclusion

These results indicate that TGF‐β–mediated MAPK signaling contributes to WM injury after ICH, which can be altered by minocycline treatment.

Attenuation of White Matter Damage Following Deferoxamine Treatment in Rats After Spinal Cord Injury

BACKGROUND

With little information available on axonal and myelin damage surrounding the contusion, the study of spinal cord injury (SCI) so far has focused on neuronal death. In this study, we investigated the role of iron overload in long-term oligodendroglia death and progressive white matter damage to rats after SCI using the iron chelator, deferoxamine (DFX).

METHODS

Female Sprague-Dawley rats received either a contusion at T10 or sham-surgery. The rats were treated with DFX or vehicle. All rats were evaluated in behavioral assessments and then euthanized at different time points. Spinal cords were analyzed by diaminobenzidine-enhanced Perls' staining, non-heme iron measurements, Western blotting, immunohistochemistry, and transmission electron microscopy.

RESULTS

Iron accumulation after SCI resulted in the upregulation of transferrin receptor and divalent metal transporter 1, which exacerbated the intracellular iron overload. DFX treatment reduced iron overload-induced delayed oligodendrocyte death (e.g., 21 days: 47.12 ± 10.5 vs. 20.02 ± 9.4 x 10³/mm² in the vehicle-treated group, n = 4, P < 0.05). After SCI, the markers of axonal damage and demyelination were increased in white matter in the vehicle-treated group compared with the DFX-treated group (P < 0.05).

CONCLUSIONS

Iron overload plays an important role in progressive white matter damage after SCI. DFX may be an effective treatment for white matter damage after SCI.

Associations between blood and cerebrospinal fluid flow impairments assessed with phase-contrast MRI and brain damage in patients with age-related cerebral small vessel disease

Hemodynamic parameters of blood and cerebrospinal fluid (CSF) flow can be measured in vivo using phase-contrast MRI (PC-MRI). This opens new horizons for studying the mechanisms implicated in the development and progression of age-related cerebral small vessel disease (SVD). In this paper, we analyze associations between cerebral arterial, venous and CSF flow impairments and SVD features visible on MRI. The study was carried out in 96 patients with SVD (aged 60.91 ± 6.57 years) and 23 healthy volunteers (59.13 ± 6.56 years). The protocol of the MRI examination included routine MRI sequences (T2, FLAIR, T1, SWI, and DWI) applied to assess the severity of brain damage according to STRIVE advisory standards and PC-MRI used to quantify blood flow in the major arteries and veins of the neck, the straight and upper sagittal sinuses, and CSF flow at the aqueduct level. We analyzed the associations between linear and volumetric parameters of blood/CSF flow and the degree of brain matter damage using the Fazekas scale. We observed a reduction in tABF, stVBF, sssVBF, aqLF, Saq, and ICC values and a rise in Pi associated with WMH progression, as well as a gradual decline in tABF and an increase in Pi, Saq and ICC associated with a growing number of lacunes (р < 0.05). Patients with early (< 5) MB had lower sssVBF and stVBF rates in comparison with patients without MB; aqLF, Saq, and ICC values were elevated in patients with 5 to 10 MB, as compared to patients without MB or early (< 5) MB. The established associations between MRI findings in patients with SVD and blood/CSF flow impairments suggest the important role of mechanisms implicated in the disruption of Monro–Kellie intracranial homeostasis in promoting SVD.

Genetic Factors of Cerebral Small Vessel Disease and Their Potential Clinical Outcome

Cerebral small vessel diseases (SVD) have been causally correlated with ischemic strokes, leading to cognitive decline and vascular dementia. Neuroimaging and molecular genetic tests could improve diagnostic accuracy in patients with potential SVD. Several types of monogenic, hereditary cerebral SVD have been identified: cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL), cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), cathepsin A-related arteriopathy with strokes and leukoencephalopathy (CARASAL), hereditary diffuse leukoencephalopathy with spheroids (HDLS), COL4A1/2-related disorders, and Fabry disease. These disorders can be distinguished based on their genetics, pathological and imaging findings, clinical manifestation, and diagnosis. Genetic studies of sporadic cerebral SVD have demonstrated a high degree of heritability, particularly among patients with young-onset stroke. Common genetic variants in monogenic disease may contribute to pathological progress in several cerebral SVD subtypes, revealing distinct genetic mechanisms in different subtype of SVD. Hence, genetic molecular analysis should be used as the final gold standard of diagnosis. The purpose of this review was to summarize the recent discoveries made surrounding the genetics of cerebral SVD and their clinical significance, to provide new insights into the pathogenesis of cerebral SVD, and to highlight the possible convergence of disease mechanisms in monogenic and sporadic cerebral SVD.

Prospectively collected lifestyle and health information as risk factors for white matter hyperintensity volume in stroke patients

Most studies of white matter hyperintensity volume (WMHV) in stroke patients lack reliable information on antecedent exposure to vascular risk factors. By leveraging prospective cohort data, we explored associations between lifestyle and health factors assessed 1 year prior to stroke and WMHV in individuals who experienced an ischemic stroke. This analysis was nested within two large prospective studies of initially healthy individuals. Information on lifestyle factors and health conditions was collected prior to the stroke event through annual or biannual questionnaires. For individuals who experienced their first confirmed ischemic stroke and had available magnetic resonance imaging, we measured WMHV using a validated semiautomated method. Linear regression was used to explore associations between lifestyle factors and health conditions and log-transformed WMHV. We measured WMHV in 345 participants with a first ischemic stroke event (mean age = 74.4 years; 24.9% male). After multivariate adjustment, history of diabetes was associated with decreased WMHV (p value = 0.06) while history of transient ischemic attack (p value = 0.09) and hypertension (p value = 0.07) were associated with increased WMHV. Most lifestyle factors and health conditions measured 1 year prior to stroke were not associated with WMHV measured at the time of ischemic stroke. Future studies could examine whether long term exposure to these factors impacts diffuse microvascular ischemic brain injury among stroke patients.

Characterization of White Matter Hyperintensities in Large-Scale MRI-Studies

Background: White matter hyperintensities of presumed vascular origin (WMH) are a common finding in elderly people and a growing social malady in the aging western societies. As a manifestation of cerebral small vessel disease, WMH are considered to be a vascular contributor to various sequelae such as cognitive decline, dementia, depression, stroke as well as gait and balance problems. While pathophysiology and therapeutical options remain unclear, large-scale studies have improved the understanding of WMH, particularly by quantitative assessment of WMH. In this review, we aimed to provide an overview of the characteristics, research subjects and segmentation techniques of these studies.

Methods: We performed a systematic review according to the PRISMA statement. One thousand one hundred and ninety-six potentially relevant articles were identified via PubMed search. Six further articles classified as relevant were added manually. After applying a catalog of exclusion criteria, remaining articles were read full-text and the following information was extracted into a standardized form: year of publication, sample size, mean age of subjects in the study, the cohort included, and segmentation details like the definition of WMH, the segmentation method, reference to methods papers as well as validation measurements.

Results: Our search resulted in the inclusion and full-text review of 137 articles. One hundred and thirty-four of them belonged to 37 prospective cohort studies. Median sample size was 1,030 with no increase over the covered years. Eighty studies investigated in the association of WMH and risk factors. Most of them focussed on arterial hypertension, diabetes mellitus type II and Apo E genotype and inflammatory markers. Sixty-three studies analyzed the association of WMH and secondary conditions like cognitive decline, mood disorder and brain atrophy. Studies applied various methods based on manual (3), semi-automated (57), and automated segmentation techniques (75). Only 18% of the articles referred to an explicit definition of WMH.

Discussion: The review yielded a large number of studies engaged in WMH research. A remarkable variety of segmentation techniques was applied, and only a minority referred to a clear definition of WMH. Most addressed topics were risk factors and secondary clinical conditions. In conclusion, WMH research is a vivid field with a need for further standardization regarding definitions and used methods.

Spatial Signature of White Matter Hyperintensities in Stroke Patients

Purpose: White matter hyperintensity (WMH) is a common phenotype across a variety of neurological diseases, particularly prevalent in stroke patients; however, vascular territory dependent variation in WMH burden has not yet been identified. Here, we sought to investigate the spatial specificity of WMH burden in patients with acute ischemic stroke (AIS). Materials and Methods: We created a novel age-appropriate high-resolution brain template and anatomically delineated the cerebral vascular territories. We used WMH masks derived from the clinical T2 Fluid Attenuated Inverse Recovery (FLAIR) MRI scans and spatial normalization of the template to discriminate between WMH volume within each subject's anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA) territories. Linear regression modeling including age, sex, common vascular risk factors, and TOAST stroke subtypes was used to assess for spatial specificity of WMH volume (WMHv) in a cohort of 882 AIS patients. Results: Mean age of this cohort was 65.23 ± 14.79 years, 61.7% were male, 63.6% were hypertensive, 35.8% never smoked. Mean WMHv was 11.58c ± 13.49 cc. There were significant differences in territory-specific, relative to global, WMH burden. In contrast to PCA territory, age (0.018 ± 0.002, p < 0.001) and small-vessel stroke subtype (0.212 ± 0.098, p < 0.001) were associated with relative increase of WMH burden within the anterior (ACA and MCA) territories, whereas male sex (-0.275 ± 0.067, p < 0.001) was associated with a relative decrease in WMHv. Conclusions: Our data establish the spatial specificity of WMH distribution in relation to vascular territory and risk factor exposure in AIS patients and offer new insights into the underlying pathology.

MRI Relaxometry for Quantitative Analysis of USPIO Uptake in Cerebral Small Vessel Disease

A protocol for evaluating ultrasmall superparamagnetic particles of iron oxide (USPIO) uptake and elimination in cerebral small vessel disease patients was developed and piloted. B₁-insensitive R₁ measurement was evaluated in vitro. Twelve participants with history of minor stroke were scanned at 3-T MRI including structural imaging, and R₁ and R₂* mapping. Participants were scanned (i) before and (ii) after USPIO (ferumoxytol) infusion, and again at (iii) 24–30 h and (iv) one month. Absolute and blood-normalised changes in R₁ and R₂* were measured in white matter (WM), deep grey matter (GM), white matter hyperintensity (WMH) and stroke lesion regions. R₁ measurements were accurate across a wide range of values. R₁ (p < 0.05) and R₂* (p < 0.01) mapping detected increases in relaxation rate in all tissues immediately post-USPIO and at 24–30 h. R₂* returned to baseline at one month. Blood-normalised R₁ and R₂* changes post-infusion and at 24–30 h were similar, and were greater in GM versus WM (p < 0.001). Narrower distributions were seen with R₂* than for R₁ mapping. R₁ and R₂* changes were correlated at 24–30 h (p < 0.01). MRI relaxometry permits quantitative evaluation of USPIO uptake; R₂* appears to be more sensitive to USPIO than R₁. Our data are explained by intravascular uptake alone, yielding estimates of cerebral blood volume, and did not support parenchymal uptake. Ferumoxytol appears to be eliminated at 1 month. The approach should be valuable in future studies to quantify both blood-pool USPIO and parenchymal uptake associated with inflammatory cells or blood-brain barrier leak.

Blood pressure, glycemic control, and white matter hyperintensity progression in type 2 diabetics

OBJECTIVE

To determine whether higher blood pressure mean (BPM) or hemoglobin A1c is associated with progression of white matter hyperintensity (WMH) on MRI in patients with type 2 diabetes, and whether intensive blood pressure or glycemic control can reduce that progression.

METHODS

We performed a secondary analysis of the Action to Control Cardiovascular Risk in Diabetes Memory in Diabetes (ACCORD MIND) research materials. The primary outcome is change in WMH volume (ΔWMH) between a baseline and month-40 MRI, and the primary predictor is BPM and A1c between the MRIs. Additional analyses compared ΔWMH in the intensive vs standard glycemic control randomization arms (n = 502) and intensive vs standard blood pressure control randomization arms (n = 314).

RESULTS

Higher systolic BPM, but not diastolic BPM or A1c, was associated with WMH progression. The ΔWMH in tertiles of increasing systolic BPM (115 ± 4, 127 ± 3, and 139 ± 6 mm Hg) was 0.7, 0.9, and 1.2 cm³ (p < 0.001). ΔWMH was lower in the intensive vs standard blood pressure control randomization arm (ΔWMH = 0.67 ± 0.95 vs 1.16 ± 1.13 cm³, p < 0.001), but there was no difference in the glycemic control arms (p = 0.917).

CONCLUSION

In ACCORD MIND, higher systolic blood pressure was associated with WMH progression. The intensive blood pressure control intervention reduced this progression. Comorbid diabetes and hypertension has synergistic deleterious properties that increase the risk of micro- and macrovascular complications. These results provide further support for an aggressive approach to blood pressure control in type 2 diabetics.

Monogenic, Polygenic, and MicroRNA Markers for Ischemic Stroke

Ischemic stroke (IS) is a leading disease with high mortality and disability, as well as with limited therapeutic window. Biomarkers for earlier diagnosis of IS have long been pursued. Family and twin studies confirm that genetic variations play an important role in IS pathogenesis. Besides DNA mutations found previously by genetic linkage analysis for monogenic IS (Mendelian inheritance), recent studies using genome-wide associated study (GWAS) and microRNA expression profiling have resulted in a large number of DNA and microRNA biomarkers in polygenic IS (sporadic IS), especially in different IS subtypes and imaging phenotypes. The present review summarizes genetic markers discovered by clinical studies and discusses their pathogenic molecular mechanisms involved in developmental or regenerative anomalies of blood vessel walls, neuronal apoptosis, excitotoxic death, inflammation, neurogenesis, and angiogenesis. The possible impact of environment on genetics is addressed as well. We also include a perspective on further studies and clinical application of these IS biomarkers.

Genetic variation in PLEKHG1 is associated with white matter hyperintensities (n = 11,226)

OBJECTIVE

To identify novel genetic associations with white matter hyperintensities (WMH).

METHODS

We performed a genome-wide association meta-analysis of WMH volumes in 11,226 individuals, including 8,429 population-based individuals from UK Biobank and 2,797 stroke patients. Replication of novel loci was performed in an independent dataset of 1,202 individuals. In all studies, WMH were quantified using validated automated or semi-automated methods. Imputation was to either the Haplotype Reference Consortium or 1,000 Genomes Phase 3 panels.

RESULTS

We identified a locus at genome-wide significance in an intron of PLEKHG1 (rs275350, β [SE] = 0.071 [0.013]; p = 1.6 × 10^-8), a Rho guanine nucleotide exchange factor that is involved in reorientation of cells in the vascular endothelium. This association was validated in an independent sample (overall p value, 2.4 × 10^-9). The same single nucleotide polymorphism was associated with all ischemic stroke (odds ratio [OR] [95% confidence interval (CI)] 1.07 [1.03-1.12], p = 0.00051), most strongly with the small vessel subtype (OR [95% CI] 1.09 [1.00-1.19], p = 0.044). Previous associations at 17q25 and 2p16 reached genome-wide significance in this analysis (rs3744020; β [SE] = 0.106 [0.016]; p = 1.2 × 10^-11 and rs7596872; β [SE] = 0.143 [0.021]; p = 3.4 × 10^-12). All identified associations with WMH to date explained 1.16% of the trait variance in UK Biobank, equivalent to 6.4% of the narrow-sense heritability.

CONCLUSIONS

Genetic variation in PLEKHG1 is associated with WMH and ischemic stroke, most strongly with the small vessel subtype, suggesting it acts by promoting small vessel arteriopathy.

Emerging insights from the genetics of cerebral small-vessel disease

Cerebral small-vessel disease (cSVD) is a common cause of stroke, functional decline, vascular cognitive impairment, and dementia. Pathological processes in the brain's microcirculation are tightly interwoven with pathology in the brain parenchyma, and this interaction has been conceptualized as the neurovascular unit (NVU). Despite intensive research efforts to decipher the NVU's structure and function to date, molecular mechanisms underlying cSVD remain poorly understood, which hampers the development of cSVD-specific therapies. Important steps forward in understanding the disease mechanisms underlying cSVD have been made using genetic approaches in studies of both monogenic and sporadic SVD. We provide an overview of the NVU's structure and function, the implications for cSVD, and the underlying molecular mechanisms of dysfunction that have emerged from recent genetic studies of both monogenic and sporadic diseases of the small cerebral vasculature.

Age and recurrent stroke are related to the severity of white matter hyperintensities in lacunar infarction patients with diabetes

Background and purpose

White matter hyperintensities (WMH) is identified as a marker of cerebral small vessel diseases and is a major contributor to cognitive impairment, depression, gait disturbance, and urinary incontinence. However, the risk factors for WMH in patients with type 2 diabetes mellitus (T2DM) has not been well explored. Thus, in this study, we aimed to investigate the relationship between the severity of WMH and vascular risk factors in lacunar infarction patients with T2DM.

Methods

Consecutive lacunar infarction patients with T2DM were recruited in this cross-sectional study. Paraventricular WMH (P-WMH) and deep WMH (D-WMH) were separately scored by the Fazekas scale, and classified into two categories by the severity. Vascular risk factors and clinical features were compared between the mild and severe WMH. Multiple logistic regression analysis was used to determine the relationship between severity of WMH and vascular risk factors.

Results

A total of 327 participants aged 34–91 years were enrolled in this study. Compared with the patients with mild P-WMH, the patients with severe P-WMH had higher age (P=0.031), higher proportion of hypertension (P=0.042) and stroke (P<0.001). Levels of TG, LDL, and HbA1c were significantly higher in patients with mild P-WMH. Compared with the patients with mild D-WMH the patients with severe D-WMH had higher age and hyperhomocysteinemia (HCY) level (P<0.001), higher proportion of hyperlipidemia (P=0.008), and stroke (P<0.001). Multivariable logistic regression analyses showed that higher age and recurrent stroke were independently related to severe P-WMH and D-WMH in lacunar infarction patients with T2DM.

Conclusions

Age and recurrent stroke are related to the severity of P-WMH and D-WMH in lacunar infarction patients with T2DM.

Relationship between White Matter Hyperintensities and Hematoma Volume in Patients with Intracerebral Hematoma

The relationship of white-matter hyperintensity (WMH) to intracerebral hemorrhage (ICH) remains unclear. In this retrospective study, we investigated whether the severity and progression of WMH could be related to the hematoma volume and absorption in ICH. 2338 WMH patients with ICH aged≥40 years receiving brain computed tomography (CT) imaging within 12 hours of ICH symptom onset were screened, and 227 patients were included in the final study. The severity and progression of WMH were assessed using the software programs MRICRON and ITK-SNAP on brain magnetic resonance imaging (MRI) and the hematoma volumes and absorption with ITK-SNAP software on CT. We assessed the association of WMH severity with ICH volume in 227 patients at baseline. Totally 183 of 227 patients underwent repeated CT within 14 days of ICH onset. The relationship of WMH severity to ICH absorption was analyzed in 183 patients. Additionally, among all 227 patients, 37 subjected to another MRI before ICH onset were divided into two groups according to WMH progression: non-progression and progression groups. The link between WMH progression and hematoma volume was examined. The ICH volume was significantly larger in patients with the highest WMH scores than in those with the lowest WMH scores. Larger WMH volume was independently associated with larger ICH volume (odds ratio 1.00; 95% CI, 1.00 to 1.00; P = 0.049). There was a trend towards WMH progression being related to ICH volume (P =0.049). Contrastingly, the WMH volume was not linked with hematoma absorption (P = 0.79). In conclusion, we found that greater severity and progression of WMH were associated with larger ICH volume. Our findings suggest that WMH might provide important prognostic information about patients with ICH and may have implications for treatment stratification.

Association between Leukoaraiosis and Symptomatic Intracranial Large Artery Stenoses and Occlusions: the Chinese Intracranial Atherosclerosis (CICAS) Study

Leukoaraiosis (LA) is frequently found in ischemic stroke patients, especially when those patients have intracranial atherosclerosis (ICAS). However, previous studies regarding an association of LA with cerebral large artery atherosclerosis showed conflicting results, and the relationship of LA with ICAS is uncertain. This study aimed to explore the association between LA and cerebral large artery atherosclerosis in Chinese patients with cerebral ischemia. Data were derived from the Chinese Intracranial Atherosclerosis (CICAS) study. Patients diagnosed with an ischemic stroke or transient ischemic attack (TIA) within 7 days of symptom onset were included. The analysis of magnetic resonance imaging (MRI) focused on severity of LA in periventricular and deep white matter; type of cerebral large artery stenosis; and the number, severity, and distribution of ICAS lesions. ICAS was defined as an occlusion or more than 50% stenosis of intracranial vessels on magnetic resonance angiography. Among 2420 patients included, distinct LA was observed in 898 (37.11%) patients, and the rate of LA increased significantly with an increased number of risk factors. Multivariate analysis revealed that LA was independently associated with ICAS (odds ratio [OR], 1.388; 95% confidence interval [CI], 1.132-1.702; P=0.0016). In the subgroup analysis of ICAS, LA was more frequently observed in multiple lesions (OR, 1.342; 95% CI, 1.060-1.699; P=0.0146), occlusive lesions (OR, 1.554; 95% CI, 1.214-1.998; P=0.0005), and lesions in the posterior circulation (OR, 1.360; 95% CI, 1.003-1.846; P=0.0481). In this nationwide prospective study, LA was associated with symptomatic ICAS, patients with multiple ICAS lesions, occlusive lesions, and atherosclerotic lesions in the posterior circulation were more likely to coexist with LA.

Long-term progression of white matter hyperintensities in ischemic stroke

OBJECTIVES

Studies on long-term progression of white matter hyperintensities (WMH) after ischemic stroke are scarce. Here, we sought to investigate this progression and its predictors in a cohort presenting with ischemic stroke before 70 years of age.

MATERIALS AND METHODS

Participants in the Sahlgrenska Academy Study on Ischemic Stroke who underwent magnetic resonance imaging (MRI) of the brain at index stroke were examined by MRI again after 7 years (n = 188, mean age 53 years at index stroke, 35% females). WMH at index stroke and progression were assessed according to Fazekas' grades and the WMH change scale. Stroke subtype was classified according to TOAST.

RESULTS

Marked WMH at index stroke were present in 20% of the participants and were significantly associated with age, hypertension, and subtype. Progression of WMH after 7 years was observed in 63% and 35% of the participants for subcortical and periventricular locations, respectively. Significant independent predictors of progression were age and marked WMH at baseline for both locations, whereas no significant associations were detected for vascular risk factors or subtype in multivariable analyses. In participants with no or only mild WMH at baseline, 20% showed marked WMH at follow-up. Age and hypertension, but not subtype, were independently associated with this acquisition of marked WMH.

CONCLUSIONS

Age and marked WMH at index stroke, but not stroke subtype, predicted long-term WMH progression after ischemic stroke before 70 years of age, whereas age and hypertension predicted acquisition of marked WMH in those with no or only mild WMH at baseline.

The Impact of Intracerebral Hemorrhage on the Progression of White Matter Hyperintensity

Objective: The exact relationship between white matter hyperintensity (WMH) and intracerebral hemorrhage (ICH) after ICH remains unclear. In this retrospective study, we investigated whether patients with ICH had more severe WMH progression.

Patients and Methods: A total of 2,951 patients aged ≥40 years with ICH who received brain computed tomography (CT) imaging within 12 h of ICH symptom onset were screened. Ninety patients with two fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) assessments, including 36 patients with Lobar ICH, 40 with basal ganglia region ICH and 14 with ICH at other sites, were included in the final study. We selected 90 age- and gender-matched healthy individuals with two MRI scans as the control group. The WMH volumes at baseline and follow-up were assessed using the FLAIR image by MRICRON and ITK-SNAP software, while the hematoma volumes were calculated based on the CT images using ITK-SNAP software.

Results: The annual progression rate of WMH was significantly higher in the ICH group compared with the control group (p < 0.05). Furthermore, WMH progression was associated with the ICH volume. The largest ICH volume (>30 mL) was associated with the highest annual progression rate of WMH (p < 0.05). In contrast, no trend toward an association between ICH location and the annual progression rate of WMH was observed (p > 0.05).

Conclusions: Our results showed that ICH patients had more severe WMH progression and that larger ICH volume was related to greater progression of WMH after ICH. These results could provide important prognostic information about patients with ICH.

Attention-Related Brain Activation Is Altered in Older Adults With White Matter Hyperintensities Using Multi-Echo fMRI

Cognitive decline is often undetectable in the early stages of accelerated vascular aging. Attentional processes are particularly affected in older adults with white matter hyperintensities (WMH), although specific neurovascular mechanisms have not been elucidated. We aimed to identify differences in attention-related neurofunctional activation and behavior between adults with and without WMH. Older adults with moderate to severe WMH (n = 18, mean age = 70 years), age-matched adults (n = 28, mean age = 72), and healthy younger adults (n = 19, mean age = 25) performed a modified flanker task during multi-echo blood oxygenation level dependent functional magnetic resonance imaging. Task-related activation was assessed using a weighted-echo approach. Healthy older adults had more widespread response and higher amplitude of activation compared to WMH adults in fronto-temporal and parietal cortices. Activation associated with processing speed was absent in the WMH group, suggesting attention-related activation deficits that may be a consequence of cerebral small vessel disease. WMH adults had greater executive contrast activation in the precuneous and posterior cingulate gyrus compared to HYA, despite no performance benefits, reinforcing the network dysfunction theory in WMH.

Effective Reserve: A Latent Variable to Improve Outcome Prediction in Stroke

Prediction of functional outcome after stroke based on initial presentation remains an open challenge, suggesting that an important aspect is missing from these prediction models. There exists the notion of a protective mechanism called brain reserve, which may be utilized to understand variations in disease outcome. In this work, we expand the concept of brain reserve (effective reserve) to improve prediction models of functional outcome after acute ischemic stroke (AIS). Consecutive AIS patients with acute brain magnetic resonance imaging (<48 hours) were eligible for this study. White matter hyperintensity and acute infarct volume were determined on T2 fluid attenuated inversion recovery and diffusion weighted images, respectively. Modified Rankin Scale scores were obtained at 90days poststroke. Effective reserve was defined as a latent variable using structural equation modeling by including age, systolic blood pressure, and intracranial volume measurements. Of 453 AIS patients (mean age 66.6 ± 14.7 years), 36% were male and 311 hypertensive. There was inverse association between effective reserve and 90-day modified Rankin Scale scores (path coefficient -0.18 ± 0.01, P < .01). Compared to a model without effective reserve, correlation between predicted and observed modified Rankin Scale scores improved in the effective-reserve-based model (Spearman's ρ 0.29 ± 0.18 versus 0.15 ± 0.17, P < .001). Furthermore, hypertensive patients exhibited lower effective reserve (P < 10^-6). Using effective reserve in prediction models of stroke outcome is feasible and leads to better model performance. Furthermore, higher effective reserve is associated with more favorable functional poststoke outcome and might correspond to an overall better vascular health.

[Small vessel cerebrovascular disease]

Small vessel vascular disease is a spectrum of different conditions that includes lacunar infarction, alteration of deep white matter, or microbleeds. Hypertension is the main risk factor, although the atherothrombotic lesion may be present, particularly in large-sized lacunar infarctions along with other vascular risk factors. MRI findings are characteristic and the lesions authentic biomarkers that allow differentiating the value of risk factors and defining their prognostic value.

Identification of a specific functional network altered in poststroke cognitive impairment

Objective

To study the association between poststroke cognitive impairment and defining a specific resting functional marker.

Methods

The resting-state functional connectivity 6 months after an ischemic stroke in 56 patients was investigated. Twenty-nine of the patients who had an impairment of one or several cognitive domains were compared to 27 without any cognitive deficit. We studied the whole-brain connectivity using 2 complementary approaches: graph theory to study the functional network organization and network-based statistics to explore connectivity between brain regions. We assessed the potential cortical atrophy using voxel-based morphometry analysis.

Results

The overall topological organization of the functional network was not altered in cognitively impaired stroke patients, who had the same mean node degree, average clustering coefficient, and global efficiency as cognitively healthy stroke patients. Network-based statistics analysis showed that poststroke cognitive impairment was associated with dysfunction of a whole-brain network composed of 167 regions and 178 connections, and functional disconnections between superior, middle, and inferior frontal gyri and the superior and inferior temporal gyri. These regions had connections that were specifically and positively correlated with cognitive domain scores. No intergroup differences in overall gray matter thickness and ischemic infarct topography were observed. To assess the effect of prestroke white matter hyperintensities on connectivity, we included the initial Fazekas scale in the regression model for a second network-based analysis. The resulting network was associated with the same key alterations but had fewer connections.

Conclusions

The observed functional network alterations suggest that the appearance of a cognitive impairment following stroke may be associated with a particular functional alteration, shared specifically between cognitive domains.

Carotid Intima-Media Thickness Is Associated With White Matter Hyperintensities: The Northern Manhattan Study

BACKGROUND AND PURPOSE

Brain white matter hyperintensities (WMH) have been associated with increased risk of stroke, cognitive decline, and dementia. WMH can be a manifestation of small vessel disease, although the total microvascular contribution to multifactorial WMH pathophysiology remains unknown. We hypothesized a possible relationship between carotid intima-media thickness (cIMT), an ultrasound imaging marker of subclinical vascular disease, and brain WMH in a multiethnic, elderly stroke-free community-based cohort.

METHODS

We evaluated the relationship between cIMT and WMH in the population-based Northern Manhattan Study, among individuals free of stroke. We used linear regression to examine the association of continuous measures of cIMT with quantitatively derived WMH volume, as a proportion of cranial volume, measured from fluid-attenuaded inversion recovery magnetic resonance imaging while adjusting for sociodemographics, lifestyle, and vascular risk factors.

RESULTS

In a cohort of 1229 participants (mean age, 71±9 years; 60% women, 15% White; 18% Black; 65% Hispanics), the mean cIMT was 0.71±0.08 mm and the median log-transformed WMH volume was 0.36 (interquartile range, 0.21-0.76). In a multivariable model, larger cIMT was significantly associated with greater WMH volume (β=0.046 per SD cIMT; P=0.04). Age and race/ethnicity were significant modifiers (P for age, 0.02; and P for race/ethnicity, 0.04). cIMT was associated with WMH volume in participants 70 years or older (β=0.088 per SD cIMT; P=0.01) and among Hispanics (β=0.084 per SD cIMT; P=0.003).

CONCLUSIONS

Larger cIMT was associated with greater burden of cerebral WM lesions independently of demographics and traditional vascular risk factors, particularly among elderly and Hispanic participants, who are at high risk for stroke and cognitive decline.

Structural Integrity of Normal Appearing White Matter and Sex-Specific Outcomes After Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Women have worse poststroke outcomes than men. We evaluated sex-specific clinical and neuroimaging characteristics of white matter in association with functional recovery after acute ischemic stroke.

METHODS

We performed a retrospective analysis of acute ischemic stroke patients with admission brain MRI and 3- to 6-month modified Rankin Scale score. White matter hyperintensity and acute infarct volume were quantified on fluid-attenuated inversion recovery and diffusion tensor imaging MRI, respectively. Diffusivity anisotropy metrics were calculated in normal appearing white matter contralateral to the acute ischemia.

RESULTS

Among 319 patients with acute ischemic stroke, women were older (68.0 versus 62.7 years; P=0.004), had increased incidence of atrial fibrillation (21.4% versus 12.2%; P=0.04), and lower rate of tobacco use (21.1% versus 35.9%; P=0.03). There was no sex-specific difference in white matter hyperintensity volume, acute infarct volume, National Institutes of Health Stroke Scale, prestroke modified Rankin Scale score, or normal appearing white matter diffusivity anisotropy metrics. However, women were less likely to have an excellent outcome (modified Rankin Scale score <2: 49.6% versus 67.0%; P=0.005). In logistic regression analysis, female sex and the interaction of sex with fractional anisotropy, radial diffusivity, and axial diffusivity were independent predictors of functional outcome.

CONCLUSIONS

Female sex is associated with decreased likelihood of excellent outcome after acute ischemic stroke. The correlation between markers of white matter integrity and functional outcomes in women, but not men, suggests a potential sex-specific mechanism.