Lacunar infarction and small vessel disease: pathology and pathophysiology

Association between blood viscosity and early neurological deterioration in lacunar infarction

Background

Understanding the factors related to early neurologic deterioration (END) is crucial in the management of patients with lacunar infarction. Blood viscosity is a significant factor for microvascular perfusion. We investigated the association between blood viscosity and occurrence of END in lacunar infarction.

Methods

We included consecutive patients admitted for lacunar infarction within 72 h from symptoms onset. END was defined as an increase in the National Institute of Health Stroke Scale (NIHSS) score ≥2 within 24 h of admission. Viscosity was measured within 24 h of hospitalization with a scanning capillary tube viscometer. Viscosity measured at a shear rate of 300 s⁻¹ was defined as systolic blood viscosity (SBV), whereas that measured at a shear rate of 5 s⁻¹ as diastolic blood viscosity (DBV).

Results

Of the 178 patients included (median age, 65.5; interquartile range [IQR], 56.0, 76.0], END occurred in 33 (18.5%). DBV was significantly higher in patients with END than those without END (13.3 mPa·s [IQR 11.8, 16.0] vs. 12.3 mPa·s [IQR11.0, 13.5]; P = 0.023). In the multivariate analysis, DBV was independently associated with the occurrence of END (odds ratio 1.17; 95% confidence interval 1.01–1.36; P = 0.043). Subgroup analysis showed no heterogeneity in the effect of viscosity on the occurrence of END.

Conclusions

Blood viscosity at a low shear rate (DBV) was associated with the occurrence of END in patients with lacunar infarction. Blood rheology may be important in pathophysiology of END in patients with lacunar infarction.

Homocysteine is related to enlarged perivascular spaces in the brainstem in patients with isolated pontine infarction

Background

Homocysteine is correlated with several imaging features of cerebral small vessel disease including white matter hyperintensities, lacunes, and enlarged perivascular spaces (EPVS) in the basal ganglia. However, little is known about EPVS in the brainstem. This study aimed to investigate the correlation between serum total homocysteine (tHcy) and EPVS in the brainstem in patients with acute isolated pontine infarction.

Methods

Consecutive patients with isolated pontine infarction were retrospectively enrolled. Clinical characteristics and laboratory tests including tHcy were recorded. Imaging markers of cerebral small vessel disease including EPVS in the basal ganglia (BG-EPVS), EPVS in the centrum semiovale, and EPVS in the midbrain or pons (brainstem-EPVS) were assessed using conventional magnetic resonance imaging. The relation between tHcy and EPVS of different parts in the brain was analyzed using univariate and multivariate regression model.

Results

A total of 227 patients were included (mean age 67.10 ± 9.38 years, male sex 58.6%). The frequencies of brainstem-EPVS and moderate to severe BG-EPVS accounted for 40.1% (91/227) and 40.5% (92/227) respectively. After controlling for confounding factors, multivariate logistic regression analyses showed that tHcy was an independent risk factor for both moderate to severe BG-EPVS (P = 0.003, P for trend < 0.001) and the presence of brainstem-EPVS (P < 0.001, P for trend < 0.001) in a dose-dependent manner. Furthermore, multivariate linear regression model indicated that the presence of brainstem-EPVS (β = 0.264, 95% confidence interval = 0.143-0.402, P < 0.001) and the severity of BG-EPVS (β = 0.162, 95% confidence interval = 0.024-0.197, P = 0.013) were positively associated with serum tHcy.

Conclusions

Serum tHcy is correlated with brainstem-EPVS and BG-EPVS dose-dependently. This study may support a contributing role for homocysteine in the pathophysiology of EPVS in the brainstem and the basal ganglia.

Association of compromised cerebral perfusion with lenticulostriate artery impairments in the subacute phase of branch atheromatous disease

Background Purpose:

Whether altered cerebral perfusion is associated with the pathogenesis of single subcortical infarctions (SSIs) in the lenticulostriate artery (LSA) territory remains unclear.

Objective:

We aimed to assess whether cerebral perfusion abnormalities are related to LSA impairments in the subacute phase of SSIs and then to examine their correlations with etiological subtypes of SSIs.

Methods:

A total of 110 patients with acute SSIs in the LSA territory were prospectively recruited between July 2017 and October 2021, and they underwent magnetic resonance perfusion-weighted imaging (PWI) and whole-brain vessel-wall imaging (VWI) within 7 days of stroke onset. Based on VWI, patients were assigned to one of two SSI subtypes: branch atheromatous disease (BAD, n = 78, 70.9%) or lacunar infarction related to cerebral small vessel disease (CSVD-related LI, n = 32, 29.1%). Perfusion maps and LSA morphology were also quantitatively assessed.

Results:

Based on PWI, 22 patients (20%) had hypoperfusion and 88 (80%) showed normal perfusion. Compared with normal individuals, patients with hypoperfusion showed shorter average LSA length (23.48 ± 4.81 mm versus 25.47 ± 3.74 mm, p = 0.037). Compared with patients with CSVD-related LI, patients with BAD had significantly lower relative cerebral blood flow [0.95 (IQR 0.81–1.12) versus 1.04 (IQR 0.92–1.22); p = 0.036] and cerebral blood volume [0.95 (IQR 0.84–1.15) versus 1.14 (IQR 0.97–1.27); p = 0.020] after adjusting for hypertension, number of LSA branches, and infarct volume.

Conclusion:

Compromised cerebral perfusion is associated with impairments in the LSA and with BAD pathogenesis. Perfusion magnetic resonance imaging can provide important insights into acute SSI pathophysiology, and it may be useful for determining the clinical significance of perfusion abnormalities in BAD occurrence.

The Characteristics of White Matter Hyperintensities in Patients With Migraine

Background

The presence of white matter hyperintensities (WMHs) in migraine is well-documented, but the location of WMH in patients with migraine is insufficiently researched. This study assessed WMH in patients with migraine using a modified version of the Scheltens visual rating scale, a semiquantitative scale for categorizing WMH in periventricular, lobar, basal ganglia, and infratentorial regions.

Methods

In total, 263 patients with migraine (31 men and232 women) enrolled in the American Registry for Migraine Research (ARMR) from Mayo Clinic Arizona and who had clinical brain magnetic resonance imaging (MRI) were included in this study. Those with imaging evidence for gross anatomical abnormalities other than WMHs were excluded. A board-certified neuroradiologist identified WMHs on axial T2 and fluid-attenuated inversion recovery (FLAIR) sequences. WMHs were characterized via manual inspection and categorized according to the scale's criteria.

Results

Results showed that 95 patients (36.1%, mean age: 41.8 years) had no WMHs on axial T2 and FLAIR imaging and 168 patients (63.9%, mean age: 51.4 year) had WMHs. Of those with WMHs, 94.1% (n = 158) had lobar hyperintensities (frontal: 148/158, 93.7%; parietal: 57/158, 36.1%; temporal: 35/158, 22.1%; and occipital: 9/158, 5.7%), 13/168, 7.7% had basal ganglia WMHs, 49/168, 29.1% had periventricular WMHs, and 17/168, 10.1% had infratentorial WMHs. In addition, 101/168 patients (60.1%) had bilateral WMHs and 67/168 (39.9%) had unilateral WMHs (34 right hemisphere/33 left hemisphere).

Discussion

Among ARMR participants who were enrolled by Mayo Clinic Arizona and who had clinical brain MRIs, nearly two-thirds had WMHs. The WMHs were the most common in the frontal lobes. Describing the features of WMHs in those with migraine, and comparing them with WMHs attributable to other etiologies, might be useful for developing classifiers that differentiate between migraine-specific WMH and other causes of WMH.

DNA Methylation and Ischemic Stroke Risk: An Epigenome-Wide Association Study

BACKGROUND

Ischemic stroke (IS) risk heritability is partly explained by genetics. Other heritable factors, such as epigenetics, could explain an unknown proportion of the IS risk. The objective of this study is to evaluate DNA methylation association with IS using epigenome-wide association studies (EWAS).

METHODS

 We performed a two-stage EWAS comprising 1,156 subjects. Differentially methylated positions (DMPs) and differentially methylated regions (DMRs) were assessed using the Infinium 450K and EPIC BeadChip in the discovery cohort (252 IS and 43 controls). Significant DMPs were replicated in an independent cohort (618 IS and 243 controls). Stroke subtype associations were also evaluated. Differentially methylated cell-type (DMCT) was analyzed in the replicated CpG sites using EpiDISH. We additionally performed pathway enrichment analysis and causality analysis with Mendelian randomization for the replicated CpG sites.

RESULTS

 A total of 957 CpG sites were epigenome-wide-significant (p ≤ 10^-7) in the discovery cohort, being CpG sites in the top signals (logFC = 0.058, p = 2.35 × 10^-22; logFC = 0.035, p = 3.22 × 10^-22, respectively). ZFHX3 and MAP3K1 were among the most significant DMRs. In addition, 697 CpG sites were replicated considering Bonferroni-corrected p-values (p < 5.22 × 10^-5). All the replicated DMPs were associated with risk of cardioembolic, atherothrombotic, and undetermined stroke. The DMCT analysis demonstrated that the significant associations were driven by natural killer cells. The pathway enrichment analysis showed overrepresentation of genes belonging to certain pathways including oxidative stress. ZFHX3 and MAP3K1 methylation was causally associated with specific stroke-subtype risk.

CONCLUSION

 Specific DNA methylation pattern is causally associated with IS risk. These results could be useful for specifically predicting stroke occurrence and could potentially be evaluated as therapeutic targets.

The Association of Nocturnal Blood Pressure Patterns and Other Influencing Factors With Lacunes and Enlarged Perivascular Spaces in Hypertensive Patients

Purpose

Nocturnal blood pressure dipping patterns have been associated with an increased risk of Cerebral Small Vessel Disease (CSVD), which has not been well-studied. This study is aimed to explore the association of dipping patterns and other factors with lacunes and enlarged perivascular spaces (EPVS) in patients with hypertension.

Methods

We enrolled a total of 1,322 patients with essential hypertension in this study. Magnetic resonance imaging (MRI) scans and 24-h ambulatory blood pressure (BP) monitoring were completed. Nocturnal BP decline was calculated, and then dipping patterns were classified. Patients were classified into four groups according to the performance of lacunes and EPVS in the MRI scan for statistical analysis.

Results

(1) Nocturnal BP decline showed independent negative correlation with both lacunes and EPVS while mean systolic BP (mSBP) level showed an independent positive correlation with them (P &lt; 0.05). (2) The frequency of reverse-dippers in the control group was significantly lower than that in other groups; the frequency of non-dippers in the lacunes group and EPVS group was significantly lower than that in the control group; the frequency of extreme-dippers in the EPVS group was significantly higher than that in the mixed (lacunes with EPVS) group (P &lt; 0.05).

Conclusions

Both mSBP and dipping patterns might play an important role in developing lacunes and EPVS in patients with hypertension.

Prognosis and antiplatelet therapy of small single subcortical infarcts in penetrating artery territory: a post hoc analysis of the Third China National Stroke Registry

Background

Small single subcortical infarction (SSSI) may be classified as parent artery disease-related or only branch involved according to the stenosis of parent artery. The study aimed to evaluate short-term and long-term prognoses and the effectiveness of antiplatelet therapy in SSSI.

Methods

We prospectively enrolled 2890 patients with SSSI from the Third China National Stroke Registry (CNSR-III) database from August 2015 to March 2018. We assessed clinical outcomes and antiplatelet treatment effects in patients with SSSI with and without parent artery stenosis (PAS) identified by magnetic resonance angiography.

Results

Among 2890 patients with SSSI in the perforator territory of the middle cerebral artery and the basilar artery, there were 680 (23.53%) patients with PAS and 2210 (76.47%) patients without PAS, respectively. After adjusting for potential confounders, the PAS group had a greater initial stroke severity (OR 1.262, 95% CI 1.058 to 1.505; p=0.0097) and a higher risk of ischaemic stroke recurrence at 3 months (OR 2.266, 95% CI 1.631 to 3.149; p<0.0001) and 1 year (OR 2.054, 95% CI 1.561 to 2.702; p<0.0001), as well as composite vascular events at 3 months (OR 2.306, 95% CI 1.674 to 3.178; p<0.0001) and 1 year (OR 1.983, 95% CI 1.530 to 2.570; p<0.0001), compared with the non-PAS group. In both groups, dual antiplatelet therapy was not superior to single antiplatelet therapy in preventing stroke recurrence, composite vascular events and disability.

Conclusion

PAS related to significantly higher rates of short-term and long-term stroke recurrence and composite vascular events, suggesting heterogeneous mechanisms in SSSI subgroups. The effectiveness of antiplatelet therapy for SSSI needs further investigation.

Usefulness of the Atherosclerosis Risk Score for Patients With Acute Infarction in the Lenticulostriate Artery Region

Background and purpose

Internal carotid artery intima-media thickness (IMT) and pulse wave velocity (PWV) are risk factors of cerebrovascular disease and coronary artery disease. They are known as independent predictors of arteriosclerotic disease. It has been reported that IMT and PWV are useful factors for predicting stroke subtype and/or outcome.

Coronary artery disease onset is proportional to atherosclerosis progression, and the Framingham Risk Score (FRS) and Suita score (SS) are standard risk predictors. This study examined whether FRS and SS can be useful for patient outcomes with acute infarction in the lenticulostriate artery (LSA) region without special tests or invasive procedures while using IMT or PWV as predictive factors.

Methods

We screened 629 consecutive patients with ischemic stroke and reviewed 84 patients with acute infarction in the LSA region who were admitted between January 2018 and December 2020. An early deterioration (ED) group was defined. In addition, the clinical characteristics, FRS, SS, treatment therapy, and neurovascular findings were evaluated.

Results

FRS and SS (FRS: 11.6 vs. 8.3, p < 0.01, SS: 58.2 vs. 53.7, p = 0.01, respectively), pre-symptomatic modified Rankin Scale (mRS) (p = 0.03), mRS at discharge (p < 0.01), and deterioration of manual muscle test (MMT) (<0.01) were significantly higher in patients in the ED (34 patients) group than in the no-ED group (54 patients). FRS and SS were correlated with mRS deterioration (FRS: r = 0.47; p < 0.01, SS: r = 0.23; p = 0.03). Among the laboratory parameters, total cholesterol (TC) (p < 0.01) and low-density lipoprotein cholesterol (LDL-C) (p < 0.01) were significantly higher in the ED group, and no significant differences in any acute therapeutic interventions.

Conclusion

Atherosclerosis risk scores, such as FRS and SS, may be useful for predicting outcomes in patients with acute LSA-region infarctions within 48 hours of onset.

Clinical particularities regarding rehabilitation treatment of a young patient with right pontine ischemic stroke, resulting in dysarthria and left side brachial and crural hemiparesis, and quite recent COVID-19 history

Introduction. Cerebrovascular attacks are one of the leading causes of mortality and morbidity in the world. The most severe are considered to be pontine strokes, because of the high risk of vital functions impairment. The clinical presentation of a pontine stroke can vary from the clas-sical crossed syndrome (ipsilateral cranial nerve palsy and contralateral motor and/or sensory impairment) to pure motor hemiplegia or pure sensory stroke, which are less common.1 Materials and methods. This presentation describes the case of a 39-year-old patient with a re-cent history of untreated SARS-COV 2 infection that was followed in the next month by a sudden onset of facial paralysis, dysarthria and a progressive left hemiplegia. The patient’s functional status was assessed in our Neuromuscular Clinical Division and he underwent a rehabilitation program consisting of physical, occupational and speech therapies. Multidisciplinary efforts were made in order to find the underlying cause of the pontine ischemic stroke. Results. The patient had a personal history of cardiovascular disease risk factors (essential hy-pertension and hyperlipidaemia), without other pathological brain imagining outcomes and normal bleeding tests. The suspicion of an interatrial communication was raised. The patient managed to rapidly maintain the standing posture and to practice walking with unilateral sup-port. At discharge, the facial paralysis and dysarthria were almost completely remitted. The left brachial extremity also showed signs of improvement, as the patient was able to perform flexion and extension movements of the fingers, wrist and forearm. Conclusion. To conclude, the patient’s evolution was favourable, although the certain cause of the underlying stroke has not been clarified. The neurological complications of COVID-19 in-clude ischemic strokes, and cases were reported in young adults too2,3. If this were the case, pre-vention of further cerebrovascular attacks and their complications is necessary1. Caution in terms of medium/long-term prophylactic anticoagulant therapy and careful control of associated cardiovascular disease risk factors has been proposed and discussed in the multidisciplinary team: rehabilitation physician, neurologist, cardiologist. Keywords: cerebrovascular attacks, COVID-19, cardiovascular disease risk factors, ischemic strokes, reha-bilitation

Blood Pressure Rhythm and Blood Pressure Variability as Risk Factors for White Matter Lesions: A Cross-Sectional Study

Background

White matter lesions are common in the elderly. The aim of this study was to explore the correlation between blood pressure rhythm and blood pressure variability with white matter lesions.

Material/Methods

A total of 144 subjects aged 40 to 80 years underwent MRI scanning to assess the degree of white matter lesions using the Fazekas scale. The regional cerebral blood flow was detected by brain perfusion imaging, and an ambulatory blood pressure monitor was used to measure the circadian blood pressure rhythm. Odds ratio and the 95% confidence interval was computed using logistics regression analysis. The relationship between various factors and blood pressure was calculated by curve simulation.

Results

With the increase of white matter lesions, the regional cerebral blood flow at the lesion decreased gradually. Systolic blood pressure day/night difference ratio (OR=0.815, 95% CI 0.729–0.910), diastolic blood pressure day/night difference ratio (OR=0.895, 95% CI 0.831–0.964), systolic blood pressure coefficient of variation (OR=1.589, 95% CI 1.273–1.983), and diastolic blood pressure coefficient of variation (OR=1.363, 95% CI 1.150–1.616) were significantly associated with Fazekas score (P<0.05 for all).

Conclusions

Greater blood pressure variability and blood pressure rhythm disorders were associated with lower regional cerebral blood flow in patients with white matter lesions.

Associations Between Cerebral Vasoreactivity and Cognitive Function in the Middle-Aged Non-Demented Population

Background: Increasing evidence shows early vascular dysregulation in the pathophysiology of Alzheimer’s disease (AD) in elderly population. Objective: We wondered about the relationship between vascular health and cognitive performance in middle-aged adults. The present study aims to evaluate whether and which brain vascular hemodynamic parameters are associated with cognitive functions in a middle-aged, non-demented population. Methods: We recruited 490 middle-aged community-based participants (30–60 years). Transcranial color-coded sonography was used to measure cerebral vascular hemodynamics, including mean flow velocity, pulsatility index, and breath-holding index (BHI) in the middle cerebral arteries (MCAs). Cognitive functions were assessed using the Montreal Cognitive Assessment (MoCA). A multivariate linear regression model was used to determine the association between the MoCA scores and each intracranial hemodynamic parameter. Results: In 369 participants (median age 52 years [IQR 47–56], 48.8% men) with robust acoustic windows, the factors related to poorer MoCA scores were older age, less education extent, and the habitats of cigarette smoking or alcohol consumption. Multivariate analyses did not show a significant association between any intracranial hemodynamic parameters in both MCAs and MoCA scores in the total study population. Left MCA BHI was found to be significantly and independently correlated with the MoCA scores only in people aged 55–60 years (n = 111, B = 0.70, 95% confidence interval, 0.13–1.26, p = 0.017), however, not in people younger than 55 years. Conclusion: Our results emphasize the role of neurovascular abnormalities in the early pathophysiology of cognitive impairment and suggest cerebral vasoreactivity as the earliest detectable cognition-associated hemodynamic parameter.

The Potential Impact of Neuroimaging and Translational Research on the Clinical Management of Lacunar Stroke

Lacunar infarcts represent one of the most frequent subtypes of ischemic strokes and may represent the first recognizable manifestation of a progressive disease of the small perforating arteries, capillaries, and venules of the brain, defined as cerebral small vessel disease. The pathophysiological mechanisms leading to a perforating artery occlusion are multiple and still not completely defined, due to spatial resolution issues in neuroimaging, sparsity of pathological studies, and lack of valid experimental models. Recent advances in the endovascular treatment of large vessel occlusion may have diverted attention from the management of patients with small vessel occlusions, often excluded from clinical trials of acute therapy and secondary prevention. However, patients with a lacunar stroke benefit from early diagnosis, reperfusion therapy, and secondary prevention measures. In addition, there are new developments in the knowledge of this entity that suggest potential benefits of thrombolysis in an extended time window in selected patients, as well as novel therapeutic approaches targeting different pathophysiological mechanisms involved in small vessel disease. This review offers a comprehensive update in lacunar stroke pathophysiology and clinical perspective for managing lacunar strokes, in light of the latest insights from imaging and translational studies.

Prevalence and Predictors of Cerebral Microangiopathy Determined by Pulsatility Index in an Asymptomatic Population From the ILERVAS Project

Background: Little is known about the prevalence of cerebral microangiopathy (CM), which is related to cognitive impairment, in an asymptomatic population. Pulsatility index (PI) is an easily measurable parameter of cerebral vascular resistance in transcranial duplex of the middle cerebral artery (MCA) study. We aimed to determine the prevalence of CM measured by PI of MCA in low to moderate vascular risk subjects. Methods: We included 3,721 subjects between 45 and 70 years without previous history of vascular disease or diabetes mellitus and with at least one other vascular risk factor from the cross-sectional study ILERVAS (Lleida, Spain). Patients underwent transcranial duplex to determine MCA-PI. Possible CM was defined by MCA-PI >1.1. Carotid and femoral arteries ultrasound registration was done to determine the presence, the number, and the area of atheromatous plaques. Body mass index (BMI), pulse pressure (PP) and laboratory data were also recorded. Results: 439 (11.8%) subjects were excluded due to the low quality of transcranial duplex images. Median age was 57 [IQR 52, 62] years. Possible CM was found in 424 (12.9%) subjects. CM patients had higher prevalence of plaques than non-CM (77.4 vs. 66.4%, p < 0.001). PI showed a positive linear correlation with the number of territories with plaques (r = 0.130, p < 0.001), and the total plaque area (r = 0.082, p < 0.001). The predictors of possible CM were the age, male gender, and PP. Conclusions: In low-to-moderate vascular risk asymptomatic population, the proportion of abnormal brain microvascular bed determined by MCA-PI is not negligible. The planned 10-year follow-up will describe the clinical relevance of these findings.

Impact of Encephalomalacia and White Matter Hyperintensities on ASPECTS in Patients With Acute Ischemic Stroke: Comparison of Automated- and Radiologist-Derived Scores

Background: Automated software-based Alberta Stroke Program Early CT Score (ASPECTS) on unenhanced CT is associated with clinical outcomes after acute stroke. However, encephalomalacia or white matter hyperintensities (WMHs) may result in a falsely low automated ASPECTS if such findings are interpreted as early ischemia. Objective: To assess the impact of encephalomalacia and WMH on automated ASPECTS in patients with acute stroke, in comparison with radiologist-derived ASPECTS and clinical outcomes. Methods: This retrospective three-center study included 459 patients (322 men, 137 women; median age, 65 years) with acute ischemic stroke treated by IV thrombolysis who underwent baseline unenhanced CT within 6 hours after symptom onset and MRI within 24 hours after treatment. ASPECTS was determined by automated software and by three radiologists in consensus. Presence of encephalomalacia and extent of WMHs [categorized using the modified Scheltens scale (mSS)] were also determined using MRI. Kappa coefficients were used to compare ASPECTS between automated and radiologist-consensus methods. Multivariable logistic regression analyses and ROC analyses were performed to explore the predictive utility of baseline ASPECTS for unfavorable clinical outcome (90-day modified Rankin Scale score of 3-6) after thrombolysis. Results: Median automated ASPECTS was 9, and median radiologist-consensus ASPECTS was 10. Agreement between automated and radiologist-consensus ASPECTS, expressed as kappa, was 0.68, though was 0.76 in patients without encephalomalacia and 0.08 in patients with encephalomalacia. In patients without encephalomalacia, agreement decreased as the mSS score increased (e.g., 0.78 in subgroup with mSS score <10 vs 0.19 in subgroup with mSS >20). By anatomic region, agreement was highest for M5 (κ=0.52) and lowest for internal capsule (κ=0.18). In multivariable analyses, both automated (odds ratio=0.69) and radiologist-consensus (odds ratio=0.57) ASPECTS independently predicted unfavorable clinical outcome. For unfavorable outcome, automated ASPECTS had AUC of 0.70, sensitivity of 60.4%, and specificity of 71.0%, while radiologist-consensus ASPECTS had AUC of 0.72, sensitivity of 60.4%, and specificity of 80.5%. Conclusion: Presence of encephalomalacia or extensive WMH results in lower automated ASPECTS than radiologist-consensus ASPECTS, which may impact predictive utility of automated ASPECTS. Clinical Impact: When using automated ASPECTS, radiologists should manually confirm the score in patients with encephalomalacia or extensive leukoencephalopathy.

[Current state of cerebral microangiopathy in hypertension]

Hypertension is the main cause and the most important risk factor for both acute cerebrovascular accident and chronic progressive cerebrovascular insufficiency that is accompanied by severe neurological and mental disorders even to the extent of developing dementia. They are based on hypertension-induced pathology of the intracerebral arteries and cerebral microvasculature - cerebral microangiopathy that leads to small deep (lacunar) infarcts (SDIs) and diffuse cerebral white matter diseases. This review highlights the morphology, pathogenesis, clinical and neuroimaging diagnosis of hypertensive SDIs, and their differential diagnosis with atherosclerotic SDIs in the historical aspect. It is emphasized that the lacunar state of the brain in hypertension is a predictor of massive cerebral hemorrhages. Special attention is paid to current studies of the morphology and pathogenesis of diffuse changes in white matter and to the role of blood-brain barrier impermeability in the development of progressive leukoencephalopathy.

Magnetic resonance imaging assessment of cerebral small vessel disease intensification in patients with severe aortic valve stenosis

Purpose

To assess the prevalence of the neuroradiological indices of cerebral small vessel disease (CSVD) in patients with severe aortic valve stenosis (AS) in magnetic resonance imaging (MRI).

Material and methods

34 patients (age 60-90 years, 17 women and 17 men) with severe AS and 50 healthy controls (age 61-85 years, 29 women and 21 men) underwent MRI brain examinations, which were analysed for the neuroradiological indices of CSVD: hyperintensities in periventricular white matter (PVWM) and deep white matter (DWM), enlarged perivascular spaces (ePVS), lacunar strokes, and cerebral microbleeds (CMBs).

Results

PVWM hyperintensities were found in 46% of volunteers and was significantly lower (p = 0.027), corresponding to AS patients (80%), the density of lesions was higher in the AS group than in controls (p = 0.019). DWM hyperintensities were found more often in AS patients (76%) than in controls (66%) (p = 0.303), but the densities were similar in both groups. Lacunar strokes were found in 35% of AS patients and 16% of controls (p = 0.042). The average number of lacunar strokes per person was 0.9 in the AS group and 0.3 in the controls (p = 0.035). The AS group showed higher variance in the number of strokes: SD = 1.96 vs. SD = 1.06 in controls. Both prevalence and density of the ePVS and CMBs did not differ significantly between the groups.

Conclusions

Neuroradiological indices of the vascular disease do not provide an unequivocal clue to the pathogenesis of CSVD in patients with severe AS. Most observations imply that CSVD is primarily a consequence of cerebral hypoperfusion caused by AS.

Prevalence and Clinical Characteristics of Lacunar Stroke: A Hospital-Based Study

Lacunar stroke (LS) is responsible for one-quarter of the overall number of ischemic strokes with long-term complications and carries health and economic issues for patients and health care systems. Therefore, we aimed to investigate lacunar versus non-lacunar strokes in a tertiary academic center. From February 2016 to July 2019, all patients admitted to the stroke unit were retrospectively reviewed. We included LS patients and compared them to other TOAST subtypes. Hemorrhagic stroke and conditions mimicking stroke were excluded. Regression analysis was done to determine LS predictors and outcomes. A 35.5% rate of LS among 989 ischemic stroke patients was found. Most patients (71.9%) were males. Lower National Institutes of Health Stroke Scale (NIHSS) scores at admission and negative history for cardiac diseases were predictors for LS in our population. At discharge, LS patients had low NIHSS scores and shorter hospitalization periods compared to non-LS patients. In conclusion, LS was prevalent among ischemic stroke patients in our cohort. Future studies are highly needed with long follow-up intervals to identify the stroke recurrence, complications, and outcomes.

Parkinsonism and cerebrovascular disease

The relationship between cerebrovascular disease and parkinsonism is commonly seen in everyday clinical practice but remains ill-defined and under-recognised with little guidance for the practising neurologist. We attempt to define this association and to illustrate key clinical, radiological and pathological features of the syndrome of Vascular Parkinsonism (VaP). VaP is a major cause of morbidity in the elderly associated with falls, hip fractures and cognitive impairment. Although acute parkinsonism is reported in the context of an acute cerebrovascular event, the vast majority of VaP presents as an insidious syndrome usually in the context of vascular risk factors and radiological evidence of small vessel disease. There may be an anatomic impact on basal ganglia neuronal networks, however the effect of small vessel disease (SVD) on these pathways is not clear. There are now established reporting standards for radiological features of SVD on MRI. White matter hyperintensities and lacunes have been thought to be the representative radiological features of SVD but other features such as the perivascular space are gaining more importance, especially in context of the glymphatic system. It is important to consider VaP in the differential diagnosis of Parkinson disease (PD) and in these situations, neuroimaging may offer diagnostic benefit especially in those patients with atypical presentations or refractoriness to levodopa. Proactive management of vascular risk factors, monitoring of bone density and an exercise program may offer easily attainable therapeutic targets in PD and VaP. Levodopa therapy should be considered in patients with VaP, however the dose and effect may be different from use in PD. This article is part of the Special Issue "Parkinsonism across the spectrum of movement disorders and beyond" edited by Joseph Jankovic, Daniel D. Truong and Matteo Bologna.

Neurovascular Alterations in Vascular Dementia: Emphasis on Risk Factors

Vascular dementia (VaD) constitutes the second most prevalent cause of dementia in the world after Alzheimer’s disease (AD). VaD regroups heterogeneous neurological conditions in which the decline of cognitive functions, including executive functions, is associated with structural and functional alterations in the cerebral vasculature. Among these cerebrovascular disorders, major stroke, and cerebral small vessel disease (cSVD) constitute the major risk factors for VaD. These conditions alter neurovascular functions leading to blood-brain barrier (BBB) deregulation, neurovascular coupling dysfunction, and inflammation. Accumulation of neurovascular impairments over time underlies the cognitive function decline associated with VaD. Furthermore, several vascular risk factors, such as hypertension, obesity, and diabetes have been shown to exacerbate neurovascular impairments and thus increase VaD prevalence. Importantly, air pollution constitutes an underestimated risk factor that triggers vascular dysfunction via inflammation and oxidative stress. The review summarizes the current knowledge related to the pathological mechanisms linking neurovascular impairments associated with stroke, cSVD, and vascular risk factors with a particular emphasis on air pollution, to VaD etiology and progression. Furthermore, the review discusses the major challenges to fully elucidate the pathobiology of VaD, as well as research directions to outline new therapeutic interventions.

The interplay between gray matter and white matter neurodegeneration in subjective cognitive decline

Aims: To investigate the interplay between gray matter (GM) and white matter (WM) neurodegeneration in subjective cognitive decline (SCD), including thickness across the whole cortical mantle, hippocampal volume, and integrity across the whole WM.

Methods: We included 225 cognitively unimpaired individuals from a community-based cohort. Subjective cognitive complaints were assessed through 9 questions covering amnestic and non-amnestic cognitive domains. In our cohort, 123 individuals endorsed from one to six subjective cognitive complaints (i.e. they fulfilled the diagnostic criteria for SCD), while 102 individuals reported zero complaints. GM neurodegeneration was assessed through measures of cortical thickness across the whole mantle and hippocampal volume. WM neurodegeneration was assessed through measures of mean diffusivity (MD) across the whole WM skeleton. Mediation analysis and multiple linear regression were conducted to investigate the interplay between the measures of GM and WM neurodegeneration.

Results: A higher number of complaints was associated with reduced hippocampal volume, cortical thinning in several frontal and temporal areas and the insula, and higher MD across the WM skeleton, with a tendency to spare the occipital lobe. SCD-related cortical thinning and increased MD were associated with each other and jointly contributed to complaints, but the contribution of cortical thinning to the number of complaints was stronger.

Conclusions: Neurodegeneration processes affecting the GM and WM seem to be associated with each other in SCD and include brain areas other than those typically targeted by Alzheimer’s disease. Our findings suggest that SCD may be a sensitive behavioral marker of heterogeneous brain pathologies in individuals recruited from the community.

Cystlike Lesions as a Late Sequela of Radiotherapy in Pediatric Patients

BACKGROUND AND PURPOSE

The developing nervous system is particularly vulnerable to late adverse effects of cranial radiation therapy, such as leukoencephalopathy, microbleeds, and cavernomas. Cystlike lesions have been rarely described and characterized in the literature. We aimed to characterize cystlike lesions, their risk factors, and association with other late adverse effects.

MATERIALS AND METHODS

Children treated for brain tumors during a 30-year period (n = 139) were included. We documented imaging findings, focusing on cystlike lesion development and its relationship with clinical history and other imaging findings. Multivariable analysis was performed using logistic regression and negative binomial regression models.

RESULTS

Cystlike lesions developed in 16.5% of patients treated with radiotherapy, with a median of 2 years until the development of the first lesion. For every 4-year age increase, there were 50% decreased odds of developing lesions and a 50% decrease in the average count of lesions. Females demonstrated a 4.00 rate ratio of developing a higher number of lesions. Patients who underwent chemoradiotherapy had 3.20 increased odds of developing cystlike lesions compared with patients with radiation therapy alone. A larger proportion of patients treated with methotrexate (25%) developed cystlike lesions, but this was not statistically significant. Cystlike lesions tended to develop in cerebral locations where leukoencephalopathy was worse. A strong relationship was found between the development of cystlike lesions and leukoencephalopathy severity.

CONCLUSIONS

Cystlike lesions are frequent and under-reported late adverse effects of cranial radiation therapy in children. Younger age, chemoradiotherapy, and the severity of leukoencephalopathy represent risk factors for the development of cystlike lesions.

Deep Cerebral Perforators: Anatomical Distribution and Clinical Symptoms: An Overview

The anatomic distribution of the deep cerebral perforators is considered either a given or subject to enormous variability. Most published overviews on this topic only report findings from a limited number of anatomic dissections, and no attempt has been made to date to provide a comprehensive overview of all published data. A comprehensive literature search was performed on MEDLINE, Embase, and Google Scholar with the help of an information specialist. Three types of studies were included: (1) articles that described the anatomy and distribution territories of perforator groups arising from the arteries of the circle of Willis; (2) studies that evaluated the anatomy of the deep cerebral perforators using imaging techniques; and (3) studies that evaluated either microsurgically or radiologically confirmed perforator occlusion and reported the (magnetic resonance imaging-confirmed) distribution territory of the infarction together with a description of the clinical symptoms associated as a result of the infarction. A total of 2715 articles were screened and 53 were included. Of these, 40 dealt with the anatomic and imaging anatomy of perforator groups (37 reported results of dissections and 3 results of imaging studies), with a total of 2421 hemispheres investigated. Another 13 articles with 680 patients were included that evaluated perforator infarction territories. The deep cerebral perforator distribution shows large variability with poor concordance rates among reported studies, with the exception of the posterior communicating and anterior choroidal artery perforators. Despite the assumption that cerebral perforator anatomy is a given, studies show large variability in the anatomic distribution of various perforator groups. Perforator anatomy and relationships between perforator groups, as well as potential collateral circulation in these territories should be prioritized as a research topic in cerebrovascular disease in the near future.

Emerging Concepts in Vascular Dementia: A Review

OBJECTIVE

Vascular dementia (VaD) is the second most common cause of dementia and a major health concern worldwide. A comprehensive review on VaD is warranted for better understanding and guidance for the practitioner. We provide an updated overview of the epidemiology, pathophysiological mechanisms, neuroimaging patterns as well as current diagnostic and therapeutic approaches.

MATERIALS AND METHODS

A narrative review of current literature in VaD was performed based on publications from the database of PubMed, Scopus and Google Scholar up to January, 2021.

RESULTS

VaD can be the result of ischemic or hemorrhagic tissue injury in a particular region of the brain which translates into clinically significant cognitive impairment. For example, a cerebral infarct in the speech area of the dominant hemisphere would translate into clinically significant impairment as would involvement of projection pathways such as the arcuate fasciculus. Specific involvement of the angular gyrus of the dominant hemisphere, with resultant Gerstman's syndrome, could have a pronounced effect on functional ability despite being termed a "minor stroke". Small vessel cerebrovascular disease can have a cumulate effect on cognitive function over time. It is unfortunately well recognized that "good" functional recovery in acute ischemic or haemorrhagic stroke, including subarachnoid haemorrhage, does not necessarily translate into good cognitive recovery. The victim may often be left unable to have gainful employment, drive a car safely or handle their affairs independently.

CONCLUSIONS

This review should serve as a compendium of updated information on VaD and provide guidance in terms of newer diagnostic and potential therapeutic approaches.

Plasma Concentrations of Magnesium and Risk of Dementia: A General Population Study of 102 648 Individuals

BACKGROUND

Low and high concentrations of plasma magnesium are associated with increased risk of future all-cause dementia; however, the underlying reasons remain elusive. The magnesium ion is an important electrolyte serving as a cofactor in many enzymatic processes in the human organism. Magnesium affects both neuronal and vascular functions. We investigated the associations of plasma concentrations of magnesium associate with common subtypes of dementia as Alzheimer dementia and non-Alzheimer dementia, and potential pathways by which magnesium may affect risk of dementia.

METHODS

Plasma concentrations of magnesium were measured in 102 648 individuals from the Copenhagen General Population Study. Cox regression and natural effects mediation analyses evaluated associations with either Alzheimer dementia or non-Alzheimer dementia.

RESULTS

Multifactorially adjusted hazard ratios for non-Alzheimer dementia were 1.50(95% confidence interval (CI):1.21-1.87) for the lowest and 1.34(1.07-1.69) for the highest vs the fourth quintile (reference) of plasma magnesium concentrations. Diabetes, cumulated smoking, stroke, and systolic blood pressure mediated 10.4%(3.1-22.8%), 6.8%(1.2-14.0%), 1.3%(0.1-3.6%), and 1.0%(0.2-2.6%), respectively, in the lowest quintile, whereas stroke mediated 3.2%(0.4-11.9%) in the highest quintile. No associations were observed for Alzheimer dementia.

CONCLUSIONS

Low and high plasma magnesium concentrations were associated with high risk of vascular-related non-Alzheimer dementia, with the lowest risk observed at a concentration of 2.07 mg/dL (0.85 mmol/L). No association was observed for Alzheimer dementia. Mediation analysis suggested that diabetes may be in the causal pathway between low plasma magnesium concentrations and high risk of non-Alzheimer dementia, while cumulated smoking, stroke, and systolic blood pressure played minor mediating roles.

Clopidogrel Plus Aspirin in Patients With Different Types of Single Small Subcortical Infarction

Background: We aim to investigate the effects and safety of clopidogrel plus aspirin in patients with different types of single small subcortical infarction (SSSI) in the Clopidogrel in High-risk patients with Acute Non-disabling Cerebrovascular Events (CHANCE) trial. Methods: SSSI was defined as single DWI lesion of ≤2.0 cm. Patients with SSSI were divided into SSSI + PAD (parent artery disease) and SSSI - PAD, according to the stenosis of the parent artery. The efficacy outcome was stroke recurrence during 90-day follow-up. Cox proportional hazards models or logistic regression models were used to assess the interaction of the treatment effects of clopidogrel plus aspirin vs. aspirin alone among patients with and without PAD. Results: Among 338 patients with SSSI included in the subanalysis, 105 were with PAD and 233 without. The efficacy of clopidogrel plus aspirin compared with aspirin alone on any stroke was consistent between patients with [adjusted hazard ratio (HR) 0.84; 95% confidence interval (CI), 0.25-2.75] and without PAD (adjusted HR 1.03; 95% CI, 0.40-2.68, interaction P = 0.83). In patients with SSSI + PAD, the rate of stroke recurrence in those treated with dual antiplatelet therapy and mono antiplatelet therapy was not significantly different (10.9 vs. 13.6%, P = 0.77). The number of bleeding events was similar between the clopidogrel-aspirin group and aspirin group regardless of SSSI + PAD or SSSI - PAD. Conclusions: There was no significant difference in the efficacy of clopidogrel plus aspirin compared with aspirin alone between patients with SSSI + PAD and SSSI - PAD in the CHANCE trial. Studies in other populations and with adequate power are needed to further verify such findings.

Diabetes, stroke, and neuroresilience: looking beyond hyperglycemia

Ischemic stroke is a leading cause of morbidity and mortality among type 2 diabetic patients. Preclinical and translational studies have identified critical pathophysiological mediators of stroke risk, recurrence, and poor outcome in diabetic patients, including endothelial dysfunction and inflammation. Most clinical trials of diabetes and stroke have focused on treating hyperglycemia alone. Pioglitazone has shown promise in secondary stroke prevention for insulin-resistant patients; however, its use is not yet widespread. Additional research into clinical therapies directed at diabetic pathophysiological processes to prevent stroke and improve outcome for diabetic stroke survivors is necessary. Resilience is the process of active adaptation to a stressor. In patients with diabetes, stroke recovery is impaired by insulin resistance, endothelial dysfunction, and inflammation, which impair key neuroresilience pathways maintaining cerebrovascular integrity, resolving poststroke inflammation, stimulating neural plasticity, and preventing neurodegeneration. Our review summarizes the underpinnings of stroke risk in diabetes, the clinical consequences of stroke in diabetic patients, and proposes hypotheses and new avenues of research for therapeutics to stimulate neuroresilience pathways and improve stroke outcome in diabetic patients.

Visualization of lenticulostriate artery by intracranial dark-blood vessel wall imaging and its relationships with lacunar infarction in basal ganglia: a retrospective study

OBJECTIVES

There is close relationship between lenticulostriate arteries (LSAs) and lacunar infarctions (LIs) of the basal ganglia. The study aims to visualize the LSAs using high-resolution vessel wall imaging (VWI) on 3T system and explore the correlation between LSAs and LIs.

METHODS

Fifty-six patients with LIs in basal ganglia, and 44 age-matched control patients were enrolled and analyzed retrospectively. The raw VWI images were reformatted into coronal slices in minimum intensity projection for further observation of LSAs. The risk factors of LIs in basal ganglia were analyzed by univariate and multivariate logistic regression. The correlation and linear regression analysis between the LSAs and LIs, ipsilateral MCA-M1 plaques were investigated.

RESULTS

The total number (p < 0.01) and length (p < 0.01) of LSAs were statistically different between basal ganglias with and without LIs. The total number of LSAs and ipsilateral MCA-M1 plaques were independently related to LIs in basal ganglias. The mean length of LSAs were negatively correlated with number (r = - 0.33, p = 0.002) and volume (r = - 0.37, p = 0.001) of LIs. Age, drinking history, and mean length of LSAs were associated with LI occurrence in basal ganglia, and mean length of LSAs was correlated with larger volume of LIs.

CONCLUSIONS

Number of LSA reduction and ipsilateral MCA-M1 plaques were associated with the presence of LIs in basal ganglias. Age increasing, drinking history, and shorter LSAs were correlated with the increasing of LIs.

KEY POINTS

• Patients with LIs tend to have shorter LSAs. • The characteristics of LSAs and ipsilateral MCA-M1 plaques are associated with LIs in basal ganglias. • Age, drinking history, and mean length of LSAs are correlated with LI features in basal ganglias.

Pandemic of the aging society - sporadic cerebral small vessel disease

Age-related sporadic cerebral small vessel disease (CSVD) has gained increasing attention over the past decades because of its increasing prevalence associated with an aging population. The widespread application of and advances in brain magnetic resonance imaging in recent decades have significantly increased researchers’ understanding in the in vivo evolution of CSVD, its impact upon the brain, its risk factors, and the mechanisms that explain the various clinical manifestation associated with sporadic CSVD. In this review, we aimed to provide an update on the pathophysiology, risk factors, biomarkers, and the determinants and spectrum of the clinical manifestation of sporadic CSVD.

Comparison of plaque characteristics of small and large subcortical infarctions in the middle cerebral artery territory using high-resolution magnetic resonance vessel wall imaging

Background

The characteristics of plaque that ultimately lead to different subcortical infarctions remain unclear. We explored the differences in plaque characteristics between patients with small subcortical infarction (SSI) and large subcortical infarction (LSI) of the middle cerebral artery (MCA) using high-resolution magnetic resonance vessel wall imaging (HR-MRVWI).

Methods

The study group comprised 71 patients (mean age, 47.49±11.5 years; 55 male) with MCA territory ischemic stroke. Whole-brain HR-MRVWI was performed using a three-dimensional T1-weighted variable-flip-angle turbo spin echo (SPACE) sequence. Patients were divided into SSI and LSI groups based on routine MRI images. Plaque distribution was classified as the superior, inferior, ventral, or dorsal wall of the MCA. The number of quadrants with plaque formation, location of plaque, plaque burden (PB), arterial remodeling pattern (positive or negative), and degree of stenosis were analyzed and compared between groups.

Results

Of the 71 patients, 43 (60.6%) and 28 (39.4%) were identified as the SSI and LSI groups, respectively. The proportion of plaques involving only one quadrant was significantly higher in the SSI group, and these plaques were located in the superior or dorsal MCA vessel wall. There was no significant difference between groups in the proportion of plaques involving two or more quadrants, plaque distribution, or PB. Most plaques in both groups showed positive remodeling, and the percentage of remodeling pattern was similar. A significantly higher incidence of low-grade stenosis (<50%) was observed in the SSI group.

Conclusions

Both SSI and LSI may be associated with major intracranial artery atherosclerosis, but patients with SSI showed relatively fewer quadrants with plaque formation and a lesser degree of stenosis.

Modeling subcortical ischemic white matter injury in rodents: unmet need for a breakthrough in translational research

Subcortical ischemic white matter injury (SIWMI), pathological correlate of white matter hyperintensities or leukoaraiosis on magnetic resonance imaging, is a common cause of cognitive decline in elderly. Despite its high prevalence, it remains unknown how various components of the white matter degenerate in response to chronic ischemia.This incomplete knowledge is in part due to a lack of adequate animal model. The current review introduces various SIWMI animal models and aims to scrutinize their advantages and disadvantages primarily in regard to the pathological manifestations of white matter components. The SIWMI animal models are categorized into 1) chemically induced SIWMI models, 2) vascular occlusive SIWMI models, and 3) SIWMI models with comorbid vascular risk factors. Chemically induced models display consistent lesions in predetermined areas of the white matter, but the abrupt evolution of lesions does not appropriately reflect the progressive pathological processes in human white matter hyperintensities. Vascular occlusive SIWMI models often do not exhibit white matter lesions that are sufficiently unequivocal to be quantified. When combined with comorbid vascular risk factors (specifically hypertension), however, they can produce progressive and definitive white matter lesions including diffuse rarefaction, demyelination, loss of oligodendrocytes, and glial activation, which are by far the closest to those found in human white matter hyperintensities lesions. However, considerable surgical mortality and unpredictable natural deaths during a follow-up period would necessitate further refinements in these models. In the meantime, in vitro SIWMI models that recapitulate myelinated white matter track may be utilized to study molecular mechanisms of the ischemic white matter injury. Appropriate in vivo and in vitro SIWMI models will contribute in a complementary manner to making a breakthrough in developing effective treatment to prevent progression of white matter hyperintensities.

Cerebral Small Vessel Disease

PURPOSE OF REVIEW

This article reviews the clinical significance and neuroimaging characteristics of cerebral small vessel disease and the impact on neurologic disease and current and potential therapeutic approaches.

RECENT FINDINGS

Cerebral small vessel disease is increasingly prevalent and highly heterogeneous in neuroimaging and clinical presentation. Small subcortical infarcts, lacunes, cerebral microbleeds, cortical microinfarcts, and white matter hyperintensity of presumed vascular origin represent the major neuroimaging markers of small vessel disease. Increasing small vessel disease burden is associated with risk of incident stroke and dementia, as well as other neuropsychiatric symptoms. Current research strategies are targeting elucidation of the mechanisms of small vessel disease pathogenesis and pursuing clinical trials of therapeutic agents to reduce the clinical manifestations of cerebral small vessel disease.

SUMMARY

Cerebral small vessel disease is common in aging adults and represents a major risk factor for multiple acute and chronic neurologic diseases. Increased awareness of cerebral small vessel disease as a modifiable risk factor holds potential for reducing neurologic disease morbidity and mortality across diverse populations in the United States and worldwide.

Plaque morphology in acute symptomatic intracranial atherosclerotic disease

BACKGROUND

Intracranial atherosclerotic disease (ICAD) is globally a major ischaemic stroke subtype with high recurrence. Understanding the morphology of symptomatic ICAD plaques, largely unknown by far, may help identify vulnerable lesions prone to relapse.

METHODS

We prospectively recruited patients with acute ischaemic stroke or transient ischaemic attack attributed to high-grade ICAD (60%-99% stenosis). Plaque morphological parameters were assessed in three-dimensional rotational angiography, including surface contour, luminal stenosis, plaque length/thickness, upstream shoulder angulation, axial/longitudinal plaque distribution and presence of adjoining branch atheromatous disease (BAD). We compared morphological features of smooth, irregular and ulcerative plaques and correlated them with cerebral ischaemic lesion load downstream in MRI.

RESULTS

Among 180 recruited patients (median age=60 years; 63.3% male; median stenosis=75%), plaque contour was smooth (51 (28.3%)), irregular (101 (56.1%)) or ulcerative (28 (15.6%)). Surface ulcers were mostly at proximal (46.4%) and middle one-third (35.7%) of the lesions. Most (84.4%) plaques were eccentric, and half had their maximum thickness over the distal end. Ulcerative lesions were thicker (medians 1.6 vs 1.3 mm; p=0.003), had steeper upstream shoulder angulation (56.2° vs 31.0°; p<0.001) and more adjoining BAD (83.3% vs 57.0%; p=0.033) than non-ulcerative plaques. Ulcerative plaques were significantly associated with coexisting acute and chronic infarcts downstream (35.7% vs 12.5%; adjusted OR 4.29, 95% CI 1.65 to 11.14, p=0.003). Sensitivity analyses in patients with anterior-circulation ICAD lesions showed similar results in the associations between the plaque types and infarct load.

CONCLUSIONS

Ulcerative intracranial atherosclerotic plaques were associated with vulnerable morphological features and had a higher cumulative infarct load downstream.

Association Between Low-Dose Rivaroxaban With or Without Aspirin and Ischemic Stroke Subtypes: A Secondary Analysis of the COMPASS Trial

Importance

The COMPASS (Cardiovascular Outcomes for People Using Anticoagulation Strategies) randomized clinical trial was stopped early owing to the efficacy of low-dose rivaroxaban plus aspirin in preventing major cardiovascular events. The main reason for early trial termination was the effect of combination therapy on reducing ischemic strokes.

Objective

To analyze the association between low-dose rivaroxaban with or without aspirin and different ischemic stroke subtypes.

Design, Setting, and Participants

This is a secondary analysis of a multicenter, double-blind, randomized, placebo-controlled study that was performed in 33 countries from March 12, 2013, to May 10, 2016. Patients with stable atherosclerotic vascular disease were eligible, and a total of 27 395 participants were randomized and followed up to February 6, 2017. All first ischemic strokes and uncertain strokes that occurred by this date were adjudicated using TOAST (Trial of Org 10172 in Acute Stroke Treatment) criteria. The analysis of ischemic stroke subtypes was evaluated using an intention-to-treat principle. Statistical analysis was performed from March 12, 2013, to February 6, 2017.

Interventions

Participants received rivaroxaban (2.5 mg twice a day) plus aspirin (100 mg once a day), rivaroxaban (5 mg twice a day), or aspirin (100 mg once a day).

Main Outcomes and Measures

Risk of ischemic stroke subtypes during follow-up.

Results

A total of 291 patients (66 women; mean [SD] age, 69.4 [8.5] years; 43 [14.8%] had a previous nonlacunar stroke) experienced an ischemic stroke. During the study, 49 patients (16.8%) received a diagnosis of atrial fibrillation. Applying TOAST criteria, 59 strokes (20.3%) were cardioembolic, 54 strokes (18.6%) were secondary to greater than 50% stenosis of the ipsilateral internal carotid artery, 42 strokes (14.4%) had a negative evaluation that met criteria for embolic stroke of undetermined source, and 21 strokes (7.2%) were secondary to small vessel disease. There were significantly fewer cardioembolic strokes (hazard ratio [HR], 0.40 [95% CI, 0.20-0.78]; P = .005) and embolic strokes of undetermined source (HR, 0.30 [95% CI, 0.12-0.74]; P = .006) in the combination therapy group compared with the aspirin-only group. A trend for reduction in strokes secondary to small vessel disease (HR, 0.36 [95% CI, 0.12-1.14]; P = .07) was not statistically significant. No significant difference was observed between the 2 groups in strokes secondary to greater than 50% carotid artery stenosis (HR, 0.85 [95% CI, 0.45-1.60]; P = .61). Rivaroxaban, 5 mg, twice daily showed a trend for reducing cardioembolic strokes compared with aspirin (HR, 0.57 [95% CI, 0.31-1.03]; P = .06) but was not associated with reducing other stroke subtypes.

Conclusions and Relevance

For patients with systemic atherosclerosis, low-dose rivaroxaban plus aspirin was associated with large, significant reductions in cardioembolic strokes and embolic strokes of undetermined source. However, these results of exploratory analysis need to be independently confirmed before influencing clinical practice.

Trial Registration

ClinicalTrials.gov identifier: NCT01776424.

Factors Associated With the Occurrence and Evolution of Recent Small Subcortical Infarcts (RSSIs) in Different Locations

Recent small subcortical infarcts (RSSIs) can occur in different brain regions. Distinct etiologies might be involved for RSSIs in different locations and could further affect RSSI cavitation and functional outcomes. In this study, we aim to analyze the baseline clinical and imaging characteristics associated with the occurrence and cavitation of RSSIs in different locations. We retrospectively include patients who presented with RSSIs from a database for cerebral small vessel disease. Detailed information, including demographic, clinical, laboratory, and radiological data, were collected. We identify baseline RSSIs on diffusion-weighted images and divide them into brainstem, subcortical white matter, and basal ganglia region groups. Cavitation is evaluated on follow-up T2 fluid-attenuated inversion recovery (FLAIR) images. Statistical analysis is performed to determine factors associated with the occurrence and cavitation of RSSIs in different locations. We find that patients with brainstem RSSIs have a higher proportion of diabetes (64.1%) compared to patients with subcortical white matter (27.3%, P < 0.001) and basal ganglia region RSSIs (35.2%, P = 0.006) and have higher levels of HbA1c (7.20%) compared to patients with subcortical white matter (6.10%, P = 0.001) and basal ganglia region RSSIs (6.20%, P = 0.003). In addition, patients with brainstem RSSIs have higher NIHSS scores than patients with subcortical white matter RSSIs (2 vs 0, P = 0.001). Patients with subcortical white matter RSSIs have higher a white matter hyperintensity (WMH) burden compared to patients with basal ganglia region RSSIs (21.64 cm³ vs 11.10 cm³, P = 0.004). Follow-up analysis demonstrates that basal ganglia region RSSIs are less likely to cavitate than subcortical white matter RSSIs (61.4% vs 83.6%, P = 0.010), and contacting with WMH is associated with the cavitation of subcortical white matter RSSIs (OR: 101.760, P = 0.003). Our study demonstrates that RSSIs in different locations are associated with different clinical and imaging characteristics. Furthermore, cavitation of RSSIs might be affected by local lesion features and the surrounding environment rather than general demographic and clinical factors.

Role of deep medullary veins in pathogenesis of lacunes: Longitudinal observations from the CIRCLE study

Our purpose is to assess the role of deep medullary veins in pathogenesis of lacunes in patients with cerebral small vessel disease (cSVD). We included patients with baseline and 2.5-year follow-up MRI in CIRCLE study. Susceptibility Weighted Imaging-Phase images were used to evaluate deep medullary veins based on a brain region-based visual score, and T2-Fluid-Attenuated-Inversion-Recovery images were used to evaluate lacunes. Cerebral blood flow and microstructural parameters in white matter hyperintensities and normal appearing white matter were also analyzed. A total of 203 cSVD patients were analyzed and 101 (49.8%) patients had baseline lacunes. Among them, 64 patients had follow-up MRI, including 16 (25.0%) with new lacunes. The patients' deep medullary veins median score was 9 (7-12). At baseline, high deep medullary veins score was independently associated with the presence of lacunes after adjusting for age, diabetes mellitus, white matter hyperintensities volume and cerebral blood flow or white matter microstructural parameters (all p < 0.001). Longitudinally, high deep medullary veins score was independently associated with new lacunes after adjusting for gender (p < 0.001). The association was also independent of white matter hyperintensities volumes, cerebral blood flow or white matter microstructural parameters (all p < 0.05). Our results suggest that deep medullary veins disruption might be involved in pathogenesis of lacunes.

Lacunar Infarction Caused by Chronic Subdural Hematoma

In chronic subdural hematoma (CSDH) patients, motor functions usually recover quickly after burr-hole surgery; however, in a rare case, the hemiparesis showed poor improvement after surgery. In that case, investigation of cerebral infarctions is important. Among the 284 CSDH patients with motor weakness, magnetic resonance image (MRI) and MR angiography (MRA) were acquired in 82 patients before surgery when the hemiparesis progressed rapidly. Small lacunar infarction was identified on the hematoma side in five cases; all were older than 80 years with hypertension, and diabetes mellitus had been diagnosed in two. In all the five patients (100%), MRA demonstrated a downward or upward shift of the M1 portion of the middle cerebral artery on the hematoma side, where the perforating arteries originate. Conversely, only 4 CSDH patients (5.2%) without lacunar infarction demonstrated M1 downward shift. The risk factors of lacunar infarction were high in the five detected cases; however, distortion, twisting, or elongation of the lenticulostriate arteries might be a cause of the lacunar infarctions, rather than the formation of lipohyalinosis or microatheroma in the arteries. Therefore, anti-platelet treatment might not be necessary for CSDH-inducing lacunar infarction. The lacunar infarctions caused by CSDH were small, the patients’ hemiparesis was mild, a prognosis of all the patients was good, and they recovered well from the motor weakness after physical rehabilitation. MR examinations before surgery are recommended for CSDH patients especially when a patient complains of sudden onset or rapid deterioration of motor weakness.

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.

Alterations of the Whole Cerebral Blood Flow in Patients With Different Total Cerebral Small Vessel Disease Burden

Background

Cerebral small vessel disease (CSVD) is a common age-related vascular disease of the brain associated with slowly accumulating tissue damage. At present, total CSVD burden score is a commonly used method to evaluate the severity of the disease.

Purpose

To observe whether global and regional cerebral perfusion is related to total CSVD score and to explore global and regional cerebral blood flow (CBF) changes in patients with different degrees of CSVD.

Methods

We collected 130 subjects with different total burden score of CSVD (0 point: 33 subjects, 1 point: 39 subjects, 2 points: 24 subjects, 3 points: 24 subjects, 4 points: 10 subjects). Total CSVD burden score was evaluated by clinically routine sequences (T2WI, T2-FLAIR, T1WI, DWI, and SWAN sequence). Global and regional CBF were calculated and correlation analysis was used to investigate the relationship between total CSVD score and CBF of the whole brain and several brain regions.

Results

The analysis results showed that there was a negative correlation between total CSVD burden score and global CBF (r = −0.33, p = 0.001). Total CSVD burden score also had moderately negative correlations with CBF of almost all the brain regions.

Conclusion

CSVD is a disease that affects the whole brain. With the increase of total CSVD burden score, the global and regional CBF decreased. The CSVD total burden score could be used to evaluate the overall condition of brain perfusion.

Reduced Myocardial Perfusion Reserve in Type 2 Diabetes Is Caused by Increased Perfusion at Rest and Decreased Maximal Perfusion During Stress

OBJECTIVE

To examine differences in myocardial blood flow (MBF) at rest and during stress between patients with type 2 diabetes and control subjects, and to identify potential predictors of changes in MBF at rest and during stress.

RESEARCH DESIGN AND METHODS

A cross-sectional study was conducted of 193 patients with type 2 diabetes and 20 age- and sex-matched control subjects. Cardiovascular magnetic resonance was used to evaluate left ventricular structure and function and MBF at rest and during adenosine-induced stress. MBF was derived as the mean of the flow within all segments of a midventricular slice.

RESULTS

Patients with type 2 diabetes had higher global MBF at rest (0.81 ± 0.19 mL/min/g) and lower global MBF during stress (2.4 ± 0.9 mL/min/g) than control subjects (0.61 ± 0.11 at rest, 3.2 ± 0.8 mL/min/g under stress; both P < 0.01). Patients with macroalbuminuria had lower MBF during stress (1.6 ± 0.5 mL/min/g) than did patients with microalbuminuria (2.1 ± 0.7 mL/min/g; P = 0.04), who in turn had lower MBF during stress than did normoalbuminuric patients (2.7 ± 0.9 mL/min/g; P < 0.01). Patients with severe retinopathy had lower MBF during stress (1.8 ± 0.6 mL/min/g) than patients with simplex retinopathy (2.3 ± 0.7 mL/min/g; P < 0.05) and those who did not have retinopathy (2.6 ± 1.0 mL/min/g; P < 0.05). Albuminuria and retinopathy were associated with reduced MBF during stress in a multiple regression analysis. Stress-related MBF inversely correlated with myocardial extracellular volume (P < 0.001; R ² = 0.37), a measure of diffuse myocardial fibrosis. A trend toward lower basal MBF was observed in patients treated with sodium-glucose cotransporter 2 inhibitors (P = 0.07).

CONCLUSIONS

Patients with type 2 diabetes have higher global MBF at rest and lower maximal MBF during vasodilator-induced stress than control subjects. Reduced MBF during stress is associated with diabetes complications (albuminuria and retinopathy) and is inversely correlated with diffuse myocardial fibrosis.

Significance of recanalization of sinuses and resolution of parenchymal lesion in cerebral venous sinus thrombosis

In cerebral venous sinus thrombosis (CVST), the degree of recanalization may determine resolution of parenchymal lesion and clinical outcome. The aim of our study was to evaluate the relationship of recanalization with resolution of MRI lesion and clinical outcome. The patients with CVST diagnosed on the basis of magnetic resonance venography (MRV) were included prospectively. Risk factors, clinical features, and MRI and MRV findings were noted. MRI and MRV were repeated at 6 months and the change in parenchymal lesion and grade of recanalization (I, II, III) were noted. Patients were evaluated clinically at three and six months. Complete recovery was considered if modified Rankin Scale (mRS) score was 0. Thirty-three CVST patients were included, 12 (36.4%) of whom were females. Recanalization occurred in 29 (87.9%), which was complete (grade III) in 6 (21%). Sigmoid sinus (52%) recanalized more frequently. Resolution of parenchymal lesion on repeat MRI occurred in 13.3% (4/30) patients, and they had no sequelae. Degree of recanalization was not related to resolution of neurological sequelae, MRI lesion at follow up and burden of thrombosis at baseline. Varying degree of recanalization occurred in 87.9% patients with CVST, and resolution of parenchymal lesion occurred in 13.3%. Clinical outcome however was not related to recanalization.

Changes in High-Density Lipoprotein Cholesterol and Risks of Cardiovascular Events: A Post Hoc Analysis from the PICASSO Trial

BACKGROUND AND PURPOSE

Whether pharmacologically altered high-density lipoprotein cholesterol (HDL-C) affects the risk of cardiovascular events is unknown. Recently, we have reported the Prevention of Cardiovascular Events in Asian Patients with Ischaemic Stroke at High Risk of Cerebral Haemorrhage (PICASSO) trial that demonstrated the non-inferiority of cilostazol to aspirin and superiority of probucol to non-probucol for cardiovascular prevention in ischemic stroke patients (clinicaltrials.gov: NCT01013532). We aimed to determine whether on-treatment HDL-C changes by cilostazol and probucol influence the treatment effect of each study medication during the PICASSO study.

METHODS

Of the 1,534 randomized patients, 1,373 (89.5%) with baseline cholesterol parameters were analyzed. Efficacy endpoint was the composite of stroke, myocardial infarction, and cardiovascular death. Cox proportional hazards regression analysis examined an interaction between the treatment effect and changes in HDL-C levels from randomization to 1 month for each study arm.

RESULTS

One-month post-randomization mean HDL-C level was significantly higher in the cilostazol group than in the aspirin group (1.08 mmol/L vs. 1.00 mmol/L, P<0.001). The mean HDL-C level was significantly lower in the probucol group than in the non-probucol group (0.86 mmol/L vs. 1.22 mmol/L, P<0.001). These trends persisted throughout the study. In both study arms, no significant interaction was observed between HDL-C changes and the assigned treatment regarding the risk of the efficacy endpoint.

CONCLUSIONS

Despite significant HDL-C changes, the effects of cilostazol and probucol treatment on the risk of cardiovascular events were insignificant. Pharmacologically altered HDL-C levels may not be reliable prognostic markers for cardiovascular risk.

NOTCH3 is non-enzymatically fragmented in inherited cerebral small-vessel disease

The small-vessel disorder cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) arises from mutations in the human gene encoding NOTCH3 and results in vascular smooth muscle cell degeneration, stroke, and dementia. However, the structural changes in NOTCH3 involved in CADASIL etiology are unclear. Here, we discovered site-specific fragmentation of NOTCH3 protein in pathologically affected vessels of human CADASIL-affected brains. EM-based experiments to pinpoint NOTCH3 localization in these brains indicated accumulation of NOTCH3 fragmentation products in the basement membrane, collagen fibers, and granular osmiophilic material within the cerebrovasculature. Using antibodies generated against a disease-linked neo-epitope found in degenerating vascular medium of CADASIL brains, we mapped the site of fragmentation to the NOTCH3 N terminus at the peptide bond joining Asp⁸⁰ and Pro⁸¹ Cleavage at this site was predicted to separate the first epidermal growth factor (EGF)-like domain from the remainder of the protein. We found that the cleavage product from this fragmentation event is released into the conditioned medium of cells expressing recombinant NOTCH3 fragments. Mutagenesis of Pro⁸¹ abolished the fragmentation, and low pH and reducing conditions enhanced NOTCH3 proteolysis. Furthermore, substitution of multiple cysteine residues of the NOTCH3 N terminus activated proteolytic release of the first EGF-like repeat, suggesting that the elimination of multiple disulfide bonds in NOTCH3 accelerates its fragmentation. These characteristics link the signature molecular genetic alterations present in individuals with CADASIL to a post-translational protein alteration in degenerating brain arteries. The cellular consequences of these pathological NOTCH3 fragments are an important area for future investigation.

Size, shape and location of lacunar strokes and correlation with risk factors

OBJECTIVE

We evaluated a prospective cohort of 150 patients under observation in our centre for lacunar strokes. The purpose of this study was to investigate if lacunar stroke of varying size, shape and locations had different risk factors between them and possibly different mechanisms and causes.

PATIENTS AND METHODS

150 patients with a lacunar stroke were included in the present study. Infarcts were classified by size, shape and location. We evaluated the correlation between several risk factors of stroke and the radiological characteristics of the infarcts.

RESULTS

Older age was associated with the presence of a basal ganglia lesion (p < 0.001) and with the presence of a smaller lesion (trend to statistical significance, p = 0.07). Patients with infarcts >15 mm had higher NIHSS score at admission (p 0.01).

CONCLUSION

The different subtypes of lacunar infarcts have distinct pathogenesis. Further studies, with a larger numbers of patients, are necessary to confirm our data.

Practical Small Vessel Disease Score Relates to Stroke, Dementia, and Death

Background and Purpose- In the general population, we investigated the association of a recently developed cerebral small vessel disease (CSVD) sum score with stroke, dementia, and mortality. Methods- One thousand six hundred fifty-one stroke-free and nondemented participants (mean age, 73.3 years; 54.5% women) of the population-based Rotterdam Study underwent brain magnetic resonance imaging (1.5T) in 2005-2011 and were followed for stroke, dementia, and mortality until 2016-2017. The CSVD sum score was composed by counting the presence of 4 magnetic resonance imaging markers (white matter hyperintensities, lacunes, cerebral microbleeds, and perivascular spaces; range, 0-4). We determined the association of the CSVD score with risk of stroke, dementia, and mortality using Cox models, adjusting for age, sex, and other Framingham Stroke Risk Profile predictors. Additionally, we assessed mortality as a competing risk for stroke and dementia and calculated absolute risk estimates for all outcomes. Results- During a mean follow-up of 7.2 years, 66 participants developed stroke, 76 developed dementia, and 306 died. The Framingham Stroke Risk Profile-adjusted hazard ratios of 1 point higher sum score were 1.54 (95% CI, 1.16-2.03) for stroke, 1.25 (95% CI, 0.95-1.64) for dementia, and 1.15 (95% CI, 1.01-1.31) for mortality. No significant differences were seen for subdistribution hazard ratios for stroke and dementia. A higher CSVD score yielded higher absolute risk estimates for all outcomes, calculated during 10 years. Conclusions- The CSVD score is a practical measure of global vascular brain injury. A higher sum score on magnetic resonance imaging is associated with higher risk of suffering a stroke, developing dementia, and death.