Age-related small vessel disease: a potential contributor to neurodegeneration in multiple sclerosis

Myelin debris phagocytosis in demyelinating disease

Demyelinating diseases are often caused by a variety of triggers, including immune responses, viral infections, malnutrition, hypoxia, or genetic factors, all of which result in the loss of myelin in the nervous system. The accumulation of myelin debris at the lesion site leads to neuroinflammation and inhibits remyelination; therefore, it is crucial to promptly remove the myelin debris. Initially, Fc and complement receptors on cellular surfaces were the primary clearance receptors responsible for removing myelin debris. However, subsequent studies have unveiled the involvement of additional receptors, including Mac-2, TAM receptors, and the low-density lipoprotein receptor-related protein 1, in facilitating the removal process. In addition to microglia and macrophages, which serve as the primary effector cells in the disease phase, a variety of other cell types such as astrocytes, Schwann cells, and vascular endothelial cells have been demonstrated to engage in the phagocytosis of myelin debris. Furthermore, we have concluded that oligodendrocyte precursor cells, as myelination precursor cells, also exhibit this phagocytic capability. Moreover, our research group has innovatively identified the low-density lipoprotein receptor as a potential phagocytic receptor for myelin debris. In this article, we discuss the functional processes of various phagocytes in demyelinating diseases. We also highlight the alterations in signaling pathways triggered by phagocytosis, and provide a comprehensive overview of the various phagocytic receptors involved. Such insights are invaluable for pinpointing potential therapeutic strategies for the treatment of demyelinating diseases by targeting phagocytosis.

Enlarged perivascular spaces are associated with brain microangiopathy and aging in multiple sclerosis

BACKGROUND

Growing evidence links brain-MRI enlarged perivascular spaces (EPVS) and multiple sclerosis (MS), but their role remains unclear.

OBJECTIVE

This study aimed to investigate the cross-sectional associations of EPVS with several neuroinflammatory and neurodegenerative features in a large multicentric-MS cohort.

METHODS

In total, 207 patients underwent 3T axial-T2-weighted brain-MRI for EPVS assessment (EPVS dichotomized into high/low according to ⩾ 2/< 2 rating categories). MRI biomarkers included brain-predicted age and brain-predicted age difference (brain-PAD), central vein sign (CVS)-positive lesion percentage (CVS%), paramagnetic rim and cortical lesions, T2-lesion load, and brain volumetry. The variable relative importance for EPVS-category prediction was explored using a classification random forest approach.

RESULTS

High EPVS patients were older (49 vs 44 years, p = 0.003), had ⩾ 1 vascular risk factors (VRFs; p = 0.005), lower CVS% (67% vs 78%, p < 0.001), reduced brain volumes (whole brain: 0.63 vs 0.73, p = 0.01; gray matter: 0.36 vs 0.40; p = 0.002), and older brain-predicted age (58 vs 50 years, p < 0.001). No differences were found for neuroinflammatory markers. After adjusting for age and VFRs (multivariate analyses), the high EPVS category correlated with lower CVS% (odds ratio (OR) = 0.98, 95% confidence interval (CI) = 0.96-0.99; p = 0.02), lower whole brain (OR = 0.01, 95% CI = 0.0003-0.5; p = 0.02), gray matter (OR = 0.0004, 95% CI = 0.0000004-0.4; p = 0.03) volumes, and higher brain-PAD (OR = 1.05, 95% CI = 1.01-1.09; p = 0.02). Random forest identified brain-PAD as the most important predictor of high EPVS.

CONCLUSION

EPVS in MS likely reflect microangiopathic disease rather than neuroinflammation, potentially contributing to accelerated neurodegeneration.

Diffusion imaging genomics provides novel insight into early mechanisms of cerebral small vessel disease

Cerebral small vessel disease (cSVD) is a leading cause of stroke and dementia. Genetic risk loci for white matter hyperintensities (WMH), the most common MRI-marker of cSVD in older age, were recently shown to be significantly associated with white matter (WM) microstructure on diffusion tensor imaging (signal-based) in young adults. To provide new insights into these early changes in WM microstructure and their relation with cSVD, we sought to explore the genetic underpinnings of cutting-edge tissue-based diffusion imaging markers across the adult lifespan. We conducted a genome-wide association study of neurite orientation dispersion and density imaging (NODDI) markers in young adults (i-Share study: N = 1 758, (mean[range]) 22.1[18-35] years), with follow-up in young middle-aged (Rhineland Study: N = 714, 35.2[30-40] years) and late middle-aged to older individuals (UK Biobank: N = 33 224, 64.3[45-82] years). We identified 21 loci associated with NODDI markers across brain regions in young adults. The most robust association, replicated in both follow-up cohorts, was with Neurite Density Index (NDI) at chr5q14.3, a known WMH locus in VCAN. Two additional loci were replicated in UK Biobank, at chr17q21.2 with NDI, and chr19q13.12 with Orientation Dispersion Index (ODI). Transcriptome-wide association studies showed associations of STAT3 expression in arterial and adipose tissue (chr17q21.2) with NDI, and of several genes at chr19q13.12 with ODI. Genetic susceptibility to larger WMH volume, but not to vascular risk factors, was significantly associated with decreased NDI in young adults, especially in regions known to harbor WMH in older age. Individually, seven of 25 known WMH risk loci were associated with NDI in young adults. In conclusion, we identified multiple novel genetic risk loci associated with NODDI markers, particularly NDI, in early adulthood. These point to possible early-life mechanisms underlying cSVD and to processes involving remyelination, neurodevelopment and neurodegeneration, with a potential for novel approaches to prevention.

[A role of cerebrovascular diseases in the progression of multiple sclerosis]

OBJECTIVE

To identify the association between cerebrovascular diseases (CVD) and multiple sclerosis (MS) among patients over 50 years old in two independent populations of Moscow and Tyumen.

MATERIAL AND METHODS

The study included 94 patients with MS in combination with CVD (main group) and 90 age-and sex-matched patients with MS without a vascular history (comparison group). An analysis of parameters such as disease duration, EDSS at different time points, disease progression index, duration of first remission in each population separately and in both populations together was carried out.

RESULTS

The presence of CVD in patients with MS was associated with the presence of other diseases that are associated with an increased risk of developing cerebrovascular pathology. In the main group, there was a statistically significant decrease in the duration of the first remission and an increase in the disease progression index. In addition, other diseases and syndromes were identified in the main group that, in combination with CVD in patients with MS, could lead to a worsening of the course of MS. These included arterial hypertension, diabetes mellitus, obesity, dyslipidemia, chronic venous insufficiency, and regular use of proton pump inhibitors.

CONCLUSION

Comorbid vascular pathology can affect the severity of MS from the very beginning of the disease. It can lead to a shorter duration of the first remission and a higher disease progression index, increasing the degree of disability. The combination of autoimmune-inflammatory, demyelinating, and vascular processes can worsen the prognosis for MS.

The Role and Therapeutic Implications of Inflammation in the Pathogenesis of Brain Arteriovenous Malformations

Brain arteriovenous malformations (bAVMs) are focal vascular lesions composed of abnormal vascular channels without an intervening capillary network. As a result, high-pressure arterial blood shunts directly into the venous outflow system. These high-flow, low-resistance shunts are composed of dilated, tortuous, and fragile vessels, which are prone to rupture. BAVMs are a leading cause of hemorrhagic stroke in children and young adults. Current treatments for bAVMs are limited to surgery, embolization, and radiosurgery, although even these options are not viable for ~20% of AVM patients due to excessive risk. Critically, inflammation has been suggested to contribute to lesion progression. Here we summarize the current literature discussing the role of the immune system in bAVM pathogenesis and lesion progression, as well as the potential for targeting inflammation to prevent bAVM rupture and intracranial hemorrhage. We conclude by proposing that a dysfunctional endothelium, which harbors the somatic mutations that have been shown to give rise to sporadic bAVMs, may drive disease development and progression by altering the immune status of the brain.

The effect of smoking on MRI lesion resolution in NMOSD-AQP4 and MOGAD

BACKGROUND

The effect of smoking on the resolution of magnetic resonance imaging (MRI) lesions in patients with neuromyelitis optica spectrum disorders with aquaporin-4 positive antibody (NMOSD-AQP4) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) has not been studied before.

OBJECTIVE

We aimed to determine the effect of smoking on lesion resolution in MRI and assess its correlation with clinical recovery after a relapse.

METHODS

We conducted a cohort study including NMOSD-AQP4 and MOGAD patients with acute and follow-up MRI scans. We collected demographic, clinical, imaging and smoking data. Logistic regression models were fitted to predict the effect of smoking on lesion resolution and to assess whether clinical recovery was associated with MRI lesion resolution.

RESULTS

A total of 105 patients were included (57 with NMOSD-AQP4 and 48 with MOGAD). Current and past smoking was associated with a higher risk of persistent lesions in NMOSD-AQP4 and MOGAD (risk ratio (RR) = 3.4, 95% confidence interval (CI) = 2.5-4.7, p < 0.001). Additionally, the presence of lesion resolution was associated with better clinical recovery (RR = 1.9, 95% CI = 1.7-2.2, p < 0.001).

CONCLUSION

Smoking is associated with worse MRI lesion resolution in patients with NMOSD-AQP4 and MOGAD, and lesion resolution correlates with clinical recovery. Our findings suggest a detrimental effect of smoking in inflammatory central nervous system (CNS) diseases.

Lacunes are associated with late-stage multiple sclerosis comorbidities

Multiple sclerosis (MS) is a condition that affects the veins and small blood vessels. Previous research suggests that individuals with MS have an increased risk of vascular events and higher mortality rates. However, the relationship between MS and cerebral small vessel disease (CSVD) remains uncertain. This study aims to investigate the association between MS and lacunes. A prospective observational study was conducted, including a total of 112 participants, of which 46 had MS and 66 had CSVD. All participants underwent an MRI scan and a battery of neurological functional assessments. The presence of definite lacunes and black holes was determined through the analysis of T2-weighted, T1-weighted, and FLAIR images. The occurrence of lacunes in MS patients was found to be 19.6%. Notably, the duration of MS was identified as the sole risk factor for the development of lacune lesions in MS patients [odds ratio (OR) = 1.3, 95% confidence interval (CI) = 1.1-1.6, p = 0.008]. Comparatively, MS patients with lacunes exhibited a higher frequency of attacks and larger volumes of T2 lesions compared to MS patients without lacunes. Further analysis using receiver operating characteristic (ROC) curves showed that lacune lesions had limited ability to discriminate between MS and CSVD when disease duration exceeded 6 years. The presence of small arterial lesions in the brain of individuals with MS, along with the duration of the disease, contributes to the development of lacunes in MS patients.

Gender heterogeneity in the influencing factors for cerebral microbleeds in acute ischemic stroke patients

BACKGROUND

Cerebral microbleeds (CMBs) are common in acute ischemic stroke (AIS) patients. The presence of CMBs increases the risk of hemorrhagic transformation in AIS patients, and it is also closely associated with cognitive decline and even dementia. At present, there exist different opinions on the independent risk factors for CMBs, and there is no consensus on whether there are gender differences in -post-stroke CMB. Therefore, this study sought to investigate gender heterogeneity in the influencing factors for CMBs by studying male and female AIS patients.

METHODS

This was a China-based, Single-center, retrospective review of data from 482 AIS inpatients at the Neurology Department of Hebei General Hospital (NCT05882123). Both demographic and clinical data were collected from the study subjects. Different head magnetic resonance imaging sequences were used to assess the subjects' CMBs, white matter lesions, and old lacunar infarcts (LI). Various statistical methods, including the t-test, χ2 test, and logistic regression, were used to analyze the gender heterogeneity of the influencing factors for CMBs in AIS patients.

RESULTS

When compared with the male AIS patients, the female AIS patients were older and had higher total cholesterol, triglyceride, high-density lipoprotein, low-density lipoprotein, ApoA, ApoB, and fibrinogen levels. The female AIS patients also had higher National Institute of Health Stroke Scale scores and hypertension disease composition ratios. By contrast, the proportions of female AIS patients with a history of smoking and a history of alcohol consumption were both lower than the corresponding proportions of male AIS patients. These differences were all statistically significant (p < .05). There were no statistically significant differences in the incidence and severity of CMBs between the male and female AIS patients (χ2 ＝ 0.851, 3.092, p > .05). The univariate and multivariate stepwise logistic regression analyses confirmed that age (OR = 1.074, 95% CI: 1.013-1.139, p = .016) and old LI (OR = 4.295, 95% CI: 1.062-17.375, p = .041) were independent risk factors for comorbid CMBs in the female AIS patients, while blood glucose (OR = 0.692, 95% CI: 0.494-0.968, p = .031) was an independent protective factor for comorbid CMBs in the female AIS patients. However, these factors were not found to be independent risk or protective factors for comorbid CMBs in male AIS patients.

CONCLUSION

There are gender differences in the influencing factors for CMBs in AIS patients. Age, old LIs, and blood glucose are independent risk or protective factors for comorbid CMBs in female AIS patients, although they are not associated with the risk of developing CMBs in male AIS patients.

Regional contribution of vascular dysfunction in white matter dementia: clinical and neuropathological insights

The maintenance of adequate blood supply and vascular integrity is fundamental to ensure cerebral function. A wide range of studies report vascular dysfunction in white matter dementias, a group of cerebral disorders characterized by substantial white matter damage in the brain leading to cognitive impairment. Despite recent advances in imaging, the contribution of vascular-specific regional alterations in white matter dementia has been not extensively reviewed. First, we present an overview of the main components of the vascular system involved in the maintenance of brain function, modulation of cerebral blood flow and integrity of the blood-brain barrier in the healthy brain and during aging. Second, we review the regional contribution of cerebral blood flow and blood-brain barrier disturbances in the pathogenesis of three distinct conditions: the archetypal white matter predominant neurocognitive dementia that is vascular dementia, a neuroinflammatory predominant disease (multiple sclerosis) and a neurodegenerative predominant disease (Alzheimer's). Finally, we then examine the shared landscape of vascular dysfunction in white matter dementia. By emphasizing the involvement of vascular dysfunction in the white matter, we put forward a hypothetical map of vascular dysfunction during disease-specific progression to guide future research aimed to improve diagnostics and facilitate the development of tailored therapies.

Dilated Virchow-Robin spaces are a marker for arterial disease in multiple sclerosis

BACKGROUND

Virchow-Robin spaces (VRS) have been associated with neurodegeneration and neuroinflammation. However, it remains uncertain to what degree non-dilated or dilated VRS reflect specific features of neuroinflammatory pathology. Thus, we aimed at investigating the clinical relevance of VRS as imaging biomarker in multiple sclerosis (MS) and to correlate VRS to their histopathologic signature.

METHODS

In a cohort study comprising 142 MS patients and 30 control subjects, we assessed the association of non-dilated and dilated VRS to clinical and magnetic resonance imaging (MRI) outcomes. Findings were corroborated in a validation cohort comprising 63 MS patients. Brain blocks from 6 MS patients and 3 non-MS controls were histopathologically processed to correlate VRS to their tissue substrate.

FINDINGS

In our actively treated clinical cohort, the count of dilated centrum semiovale VRS was associated with increased T1 and T2 lesion volumes. There was no systematic spatial colocalization of dilated VRS with MS lesions. At tissue level, VRS mostly corresponded to arteries and were not associated with MS pathological hallmarks. Interestingly, in our ex vivo cohort comprising mostly progressive MS patients, dilated VRS in MS were associated with signs of small vessel disease.

INTERPRETATION

Contrary to prior beliefs, these observations suggest that VRS in MS do not associate with an accumulation of immune cells. But instead, these findings indicate vascular pathology as a driver and/or consequence of neuroinflammatory pathology for this imaging feature.

FUNDING

NIH, Swedish Society for Medical Research, Swiss National Science Foundation and University of Zurich.

Neuropathology of microbleeds in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)

Cerebral microbleeds (CMBs) detected on magnetic resonance imaging are common in patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). The neuropathologic correlates of CMBs are unclear. In this study, we characterized findings relevant to CMBs in autopsy brain tissue of 8 patients with genetically confirmed CADASIL and 10 controls within the age range of the CADASIL patients by assessing the distribution and extent of hemosiderin/iron deposits including perivascular hemosiderin leakage (PVH), capillary hemosiderin deposits, and parenchymal iron deposits (PID) in the frontal cortex and white matter, basal ganglia and cerebellum. We also characterized infarcts, vessel wall thickening, and severity of vascular smooth muscle cell degeneration. CADASIL subjects had a significant increase in hemosiderin/iron deposits compared with controls. This increase was principally seen with PID. Hemosiderin/iron deposits were seen in the majority of CADASIL subjects in all brain areas. PVH was most pronounced in the frontal white matter and basal ganglia around small to medium sized arterioles, with no predilection for the vicinity of vessels with severe vascular changes or infarcts. CADASIL subjects have increased brain hemosiderin/iron deposits but these do not occur in a periarteriolar distribution. Pathogenesis of these lesions remains uncertain.

Dilated Virchow-Robin Spaces are a Marker for Arterial Disease in Multiple Sclerosis

Virchow-Robin spaces (VRS) have been associated with neurodegeneration and neuroinflammation. However, it remains uncertain to what degree non-dilated or dilated VRS reflect specific features of neuroinflammatory pathology. Thus, we aimed at investigating the clinical relevance of VRS as imaging biomarker in multiple sclerosis (MS) and to correlate VRS to their histopathologic signature. In a cohort study comprising 205 MS patients (including a validation cohort) and 30 control subjects, we assessed the association of non-dilated and dilated VRS to clinical and magnetic resonance imaging (MRI) out-comes. Brain blocks from 6 MS patients and 3 non-MS controls were histopathologically processed to correlate VRS to their tissue substrate. The count of dilated centrum semiovale VRS was associated with increased T1 and T2 lesion volumes. There was no systematic spatial colocalization of dilated VRS with MS lesions. At tissue level, VRS mostly corresponded to arteries and were not associated with MS pathological hallmarks. Interestingly, dilated VRS in MS were associated with signs of small vessel disease. Contrary to prior beliefs, these observations suggest that VRS in MS do not associate with accumulation of immune cells. But instead, these findings indicate vascular pathology as a driver and/or consequence of neuroinflammatory pathology for this imaging feature.

Multiple sclerosis progression: time for a new mechanism-driven framework

Traditionally, multiple sclerosis has been categorised by distinct clinical descriptors-relapsing-remitting, secondary progressive, and primary progressive-for patient care, research, and regulatory approval of medications. Accumulating evidence suggests that the clinical course of multiple sclerosis is better considered as a continuum, with contributions from concurrent pathophysiological processes that vary across individuals and over time. The apparent evolution to a progressive course reflects a partial shift from predominantly localised acute injury to widespread inflammation and neurodegeneration, coupled with failure of compensatory mechanisms, such as neuroplasticity and remyelination. Ageing increases neural susceptibility to injury and decreases resilience. These observations encourage a new consideration of the course of multiple sclerosis as a spectrum defined by the relative contributions of overlapping pathological and reparative or compensatory processes. New understanding of key mechanisms underlying progression and measures to quantify progressive pathology will potentially have important and beneficial implications for clinical care, treatment targets, and regulatory decision-making.

Predictive model of hypoxemia after shoulder arthroscopy: A retrospective observational study

The study is aimed to establish a predictive model of hypoxemia after shoulder arthroscopy. The predictive model was based on a retrospective study with 756 patients who underwent shoulder arthroscopic surgery in Sichuan Orthopaedic Hospital from June 2019 to December 2020. Independent risk factors of hypoxemia in the post-anesthesia care unit (PACU) were screened out by the binary logistics regression and the primary predictive model was completed, which was evaluated by the receiver operating characteristic (ROC) curve and Hosmer-Lemeshow goodness-of-fit test. A separate cohort of 324 patients in the PACU from January 2021 to June 2021 was enrolled to validate the predictive model. Seven hundred fifty-six patients and 19 variables were enrolled in the binary logistics regression and 324 patients were validated by the primary predictive model. Logistics regression showed that application of irrigating solution ≥20 L, age, body mass index, and number of B-lines were independent risk factors of hypoxemia in the PACU (P < .05). The risk predictive model of hypoxemia in the PACU was established according to those factors. The model was validated by the Hosmer-Lemeshow test and the area under the curve of ROC was 0.823. The model area under the curve of external effect subject ROC was 0.870. The risk predictive model established in our study can predict the risk of hypoxemia in the PACU well and have good efficacy.

Investigations of hypoxia-induced deoxyhemoglobin as a contrast agent for cerebral perfusion imaging

The assessment of resting perfusion measures (mean transit time, cerebral blood flow, and cerebral blood volume) with magnetic resonance imaging currently requires the presence of a susceptibility contrast agent such as gadolinium. Here, we present an initial comparison between perfusion measures obtained using hypoxia-induced deoxyhemoglobin and gadolinium in healthy study participants. We hypothesize that resting cerebral perfusion measures obtained using precise changes of deoxyhemoglobin concentration will generate images comparable to those obtained using a clinical standard, gadolinium. Eight healthy study participants were recruited (6F; age 23-60). The study was performed using a 3-Tesla scanner with an eight-channel head coil. The experimental protocol consisted of a high-resolution T1-weighted scan followed by two BOLD sequence scans in which each participant underwent a controlled bolus of transient pulmonary hypoxia, and subsequently received an intravenous bolus of gadolinium. The resting perfusion measures calculated using hypoxia-induced deoxyhemoglobin and gadolinium yielded maps that looked spatially comparable. There was no statistical difference between methods in the average voxel-wise measures of mean transit time, relative cerebral blood flow and relative cerebral blood volume, in the gray matter or white matter within each participant. We conclude that perfusion measures generated with hypoxia-induced deoxyhemoglobin are spatially and quantitatively comparable to those generated from a gadolinium injection in the same healthy participant.

Association of Cerebral Small Vessel Disease With Gait and Balance Disorders

Cerebral small vessel disease (CSVD) is a common cerebrovascular disease and an important cause of gait and balance disorders. Gait and balance disorders can further lead to an increased risk of falls and a decreased quality of life. CSVD can damage gait and balance function by affecting cognitive function or directly disrupting motor pathways, and different CSVD imaging features have different characteristics of gait and balance impairment. In this article, the correlation between different imaging features of sporadic CSVD and gait and balance disorders has been reviewed as follows, which can provide beneficial help for standardized management of CSVD.

Clinical, Radiological and Pathological Characteristics Between Cerebral Small Vessel Disease and Multiple Sclerosis: A Review

Cerebral small vessel disease (CSVD) and multiple sclerosis (MS) are a group of diseases associated with small vessel lesions, the former often resulting from the vascular lesion itself, while the latter originating from demyelinating which can damage the cerebral small veins. Clinically, CSVD and MS do not have specific signs and symptoms, and it is often difficult to distinguish between the two from the aspects of the pathology and imaging. Therefore, failure to correctly identify and diagnose the two diseases will delay early intervention, which in turn will affect the long-term functional activity for patients and even increase their burden of life. This review has summarized recent studies regarding their similarities and difference of the clinical manifestations, pathological features and imaging changes in CSVD and MS, which could provide a reliable basis for the diagnosis and differentiation of the two diseases in the future.

Cognitive Decline in Older People with Multiple Sclerosis—A Narrative Review of the Literature

Several important questions regarding cognitive aging and dementia in older people with multiple sclerosis (PwMS) are the focus of this narrative review: Do older PwMS have worse cognitive decline compared to older people without MS? Can older PwMS develop dementia or other neurodegenerative diseases such as Alzheimer’s disease (AD) that may be accelerated due to MS? Are there any potential biomarkers that can help to determine the etiology of cognitive decline in older PwMS? What are the neural and cellular bases of cognitive aging and neurodegeneration in MS? Current evidence suggests that cognitive impairment in MS is distinguishable from that due to other neurodegenerative diseases, although older PwMS may present with accelerated cognitive decline. While dementia is prevalent in PwMS, there is currently no consensus on defining it. Cerebrospinal fluid and imaging biomarkers have the potential to identify disease processes linked to MS and other comorbidities—such as AD and vascular disease—in older PwMS, although more research is required. In conclusion, one should be aware that multiple underlying pathologies can coexist in older PwMS and cause cognitive decline. Future basic and clinical research will need to consider these complex factors to better understand the underlying pathophysiology, and to improve diagnostic accuracy.

Central vein sign: A putative diagnostic marker for multiple sclerosis

The presence of a "central vein sign" (CVS) has been introduced as a biomarker for the diagnosis of multiple sclerosis (MS) and shown to have the ability to accurately differentiate MS from other white matter diseases (MS mimics). Following the development of susceptibility-based magnetic resonance venography that allowed the in vivo detection of CVS, a standard CVS definition was established by introducing the "40% rule" that assesses the number of MS lesions with CVS as a fraction of the total number of lesions to differentiate MS lesions from other types of lesions. The "50% rule," the "three-lesion criteria," and the "six-lesion criteria" were later introduced and defined. Each of these rules had high levels of sensitivity, specificity, and accuracy in differentiating MS from other diseases, which has been recognized by the Magnetic Resonance Imaging in MS (MAGNIMS) group and the Consortium of MS Centers task force. The North American Imaging in Multiple Sclerosis Cooperative even provided statements and recommendations aiming to refine, standardize and evaluate the CVS in MS. Herein, we review the existing literature on CVS and evaluate its added value in the diagnosis of MS and usefulness in differentiating it from other vasculopathies. We also review the histopathology of CVS and identify available automated CVS assessment methods as well as define the role of vascular comorbidities in the diagnosis of MS.

Neuroradiological differentiation of white matter lesions in patients with multiple sclerosis and Fabry disease

Objective

White matter lesions (WML) in multiple sclerosis (MS) differ from vascular WML caused by Fabry disease (FD). However, in atypical cases the discrimination can be difficult and may vary between individual raters. The aim of this study was to evaluate interrater reliability of WML differentiation between MS and FD patients.

Materials and methods

Brain MRI scans of 21 patients with genetically confirmed FD were compared to 21 matched patients with MS. Pseudonymized axial FLAIR sequences were assessed by 6 blinded raters and attributed to either the MS or the FD group to investigate interrater reliability. Additionally, localization of WML was compared between the two groups.

Results

The median age of patients was 46 years (IQR 35–58). Interrater reliability was moderate with a Fleiss' Kappa of 0.45 (95%CI 0.3–0.59). Overall, 85% of all ratings in the MS group and 75% in the FD group were correct. However, only 38% of patients with MS and 33% of patients with FD were correctly identified by all 6 raters. WML involving the corpus callosum (p < 0.001) as well as juxtacortical (p < 0.001) and infratentorial lesions (p = 0.03) were more frequently observed in MS patients.

Conclusion

Interrater reliability regarding visual differentiation of WML in MS from vascular WML in FD on standard axial FLAIR images alone is only moderate, despite the distinctive features of lesions in each group.

Multiple sclerosis and venous angioplasty for chronic cerebrospinal venous insufficiency: a case control study with ten years follow-up with patients at their own control

Progressive Neurological Diseases (PND) and Chronic Cerebrospinal Venous Insufficiency (CCSVI) and Multiple Sclerosis (MS) have two terms in common: “progressive and chronic” and shortly mean that there is no definitive therapy, at the moment. The clinical aspects are built on symptoms, upon which the definition of “progression” is based and hence classified. Changement and worsening of symptoms, allow classification of the disease and adjustments are effectively an “up to date” of the disease itself. We here resume the ten-year survey of 482 Multiple Sclerosis (MS)-affected patients (314 females, 168 males; mean age =37.8), classified by their Neurology Physicians as Relapse-Remitting (RR), according to the Kurtzke Expanded Disability Status Scale (EDSS), monitoring the parallel presence of CCSVI with clinical MS progression. Results are present from two homogeneous Relapse-Remitting MS groups of patients divided as “treated and non-treated for CCSVI” with vein angioplasty (vPTA). Furthermore, a Patient’s self-classification based upon symptoms in presence of CCSVI, up to now never implemented, was developed on the basis of both clinical and Duplex vascular issues.  

Fluid biomarkers of white matter hyperintensities in cerebrovascular disease and neurodegeneration: a systematic review protocol

OBJECTIVE

The goal of this systematic review is to evaluate the association between fluid biomarkers and white matter hyperintensities (WMH) in cerebrovascular disease and neurodegenerative disorders. While previous research has examined the etiology of WMH in specific diseases, we propose a comprehensive framework encompassing WMH of both vascular and non-vascular origin.

INTRODUCTION

Although WMH have been mostly described in aging populations with cerebrovascular disease, extensive lesions also occur in non-vascular diseases. Such lesions are traditionally treated as a separate pathological entity from vascular ones, but recent work has challenged the appropriateness of that framework when probing WMH etiology. Comparing biomarkers associated with WMH across various pathologies may improve our understanding of their etiology.

INCLUSION CRITERIA

The review will focus on cerebrovascular disease and neurodegenerative disorders and exclude infectious, metabolic, drug-induced, or radiation-induced white matter diseases. Original, peer-reviewed research on the relationship of WMH on magnetic resonance imaging with blood/cerebrospinal fluid biomarkers will be considered for inclusion. Postmortem studies will guide the selection of biomarkers of interest and the interpretation of our findings. Genomic markers will be excluded.

METHODS

The review will be conducted in accordance with PRISMA and JBI guidelines. English articles of interest published between 2000 and 2020 will be identified in MEDLINE and Embase. Two reviewers will perform abstract and full-text screening, standardized data extraction, and quality assessments of the selected studies. The relationship between each biomarker and WMH burden will be meta-analyzed, if possible, with subgroup or meta-regression analyses to assess differences between diseases.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42020218298.

Peripheral Markers of Neurovascular Unit Integrity and Amyloid-β in the Brains of Menopausal Women

BACKGROUND

The identification of blood-borne biomarkers for the diagnosis and prognosis of Alzheimer's disease and related dementias is more feasible at the population level than obtaining cerebrospinal fluid or neuroimaging markers.

OBJECTIVE

This study determined the association of blood microvesicles, derived from cells of the neurovascular unit, with brain amyloid-β deposition in menopausal women.

METHODS

A subset of women from the Kronos Early Estrogen Prevention Study underwent brain amyloid-β positron emission tomography three years following cessation of study treatment with placebo (PL, n = 29), transdermal 17β-estradiol (tE2; n = 21), or oral conjugated equine estrogen (oCEE; n = 17). Isolated peripheral venous blood microvesicles were analyzed by digital flow cytometry using fluorophore conjugated antibodies directed toward total tau, amyloid-β 1-42 (Aβ1-42), neuron specific class III β-tubulin (Tuj1), microglia ionized calcium -binding adaptor molecule 1(Iba1), glial fibrillary acid protein (GFAP), and low density lipoprotein receptor-related protein1 (LRP1). Principal components analysis reduced the dimensionality of these selected six markers to two principal components (PCs). Proportional odds ordinal logistic regression analysis was used with amyloid-β deposition regressed on these PCs.

RESULTS

Only the number of microvesicles positive for Aβ1-42 differed statistically among prior treatment groups (median [IQR]: 6.06 [2.11, 12.55] in PL; 2.49 [0.73, 3.59] in tE2; and 4.96 [0.83, 10.31] in oCEE; p = 0.032). The joint association between the 2 PCs and brain amyloid-β deposition was significant (p = 0.045).

CONCLUSION

Six selected markers expressing peripheral blood microvesicles derived from cells of the neurovascular unit, when summarized into two principal components, were associated with brain amyloid-β deposition.

Vascular disease and multiple sclerosis: a post-mortem study exploring their relationships

Vascular comorbidities have a deleterious impact on multiple sclerosis clinical outcomes but it is unclear whether this is mediated by an excess of extracranial vascular disease (i.e. atherosclerosis) and/or of cerebral small vessel disease or worse multiple sclerosis pathology. To address these questions, a study using a unique post-mortem cohort wherein whole body autopsy reports and brain tissue were available for interrogation was established. Whole body autopsy reports were used to develop a global score of systemic vascular disease that included aorta and coronary artery atheroma, cardiac hypertensive disease, myocardial infarction and ischaemic stroke. The score was applied to 85 multiple sclerosis cases (46 females, age range 39 to 84 years, median 62.0 years) and 68 control cases. Post-mortem brain material from a subset of the multiple sclerosis (n = 42; age range 39-84 years, median 61.5 years) and control (n = 39) cases was selected for detailed neuropathological study. For each case, formalin-fixed paraffin-embedded tissue from the frontal and occipital white matter, basal ganglia and pons was used to obtain a global cerebral small vessel disease score that captured the presence and/or severity of arteriolosclerosis, periarteriolar space dilatation, haemosiderin leakage, microinfarcts, and microbleeds. The extent of multiple sclerosis-related pathology (focal demyelination and inflammation) was characterized in the multiple sclerosis cases. Regression models were used to investigate the influence of disease status on systemic vascular disease and cerebral small vessel disease scores and, in the multiple sclerosis group, the relationship between multiple sclerosis-related pathology and both vascular scores. We show that: (i) systemic cardiovascular burden, and specifically atherosclerosis, is lower and cerebral small vessel disease is higher in multiple sclerosis cases that die at younger ages compared with control subjects; (ii) the association between systemic vascular disease and cerebral small vessel disease is stronger in patients with multiple sclerosis compared with control subjects; and (iii) periarteriolar changes, including periarteriolar space dilatation, haemosiderin deposition and inflammation, are key features of multiple sclerosis pathology outside the classic demyelinating lesion. Our data argue against a common primary trigger for atherosclerosis and multiple sclerosis but suggest that an excess burden of cerebral small vessel disease in multiple sclerosis may explain the link between vascular comorbidity and accelerated irreversibility disability.

The influence of smoking on the pattern of disability and relapse risk in AQP4-positive Neuromyelitis Optica Spectrum Disorder, MOG-Ab Disease and Multiple Sclerosis

BACKGROUND

the role of smoking on clinical outcomes of central nervous system (CNS) inflammatory disorders is unclear. To assess the effect of smoking on relapses and disability in neuromyelitis optica with aquaporin-4-antibodies (NMOSD-AQP4-Ab), Myelin Oligodendrocyte Glycoprotein-antibodies associated disease (MOGAD) and relapsing remitting Multiple Sclerosis (MS) patients.

METHODS

in a UK cohort of 101 NMOSD-AQP4-Ab, 70 MOGAD and 159 MS, and a Korean cohort of 97 NMOSD-AQ4-Ab, time to first relapse, annualised relapse rate, onset relapse severity and recovery, time to Expanded Disability Status Score(EDSS)/secondary progressive MS (SPMS) were compared between never-smokers and ever-smokers. All clinical data were collected under the local ethics between January 2017 and January 2019.

RESULTS

Smoking did not affect the risk of relapse in any of the diseases. The risk of reaching EDSS 6.0 in the UK NMOSD-AQP4-Ab cohort was higher in ever smokers but this did not achieve significance (HR 2.12, p=0.068). When combining the UK and Korea NMOSD-AQP4-Ab cohorts, poorer recovery from the onset attack was significantly more frequent in the ever-smokers versus the never smokers (55% vs 38%, p=0.04). In the MS cohort the risk of reaching EDSS 6 and SPMS was significantly higher in the ever-smokers (HR=2.67, p=0.01 and HR=3.18, p=0.001). In MOGAD similar patterns were seen without reaching significance.

CONCLUSIONS

In NMOSD-AQP4-Ab smoking associates with worse disability not through an increased risk of relapses but through poor relapse recovery. As in MS, smoking cessation should be encouraged in NMOSD-AQP4-Ab.

Dawson Fingers in Older Adults with Cerebral Small Vessel Disease: A Population Study

Dawson fingers are used to differentiate multiple sclerosis (MS) from other conditions that affect the subcortical white matter. However, there are no studies evaluating the presence of Dawson fingers in subjects with cerebral small vessel disease (cSVD). We aimed to assess prevalence and -correlates of Dawson fingers in older adults with cSVD-related moderate-to-severe white matter hyperintensities (WMH). Community-dwelling older adults residing in rural Ecuador - identified by means of door-to-door surveys - underwent a brain MRI. Exams of individuals with cSVD-related moderate-to-severe WMH were reviewed with attention to the presence of Dawson fingers. Of 590 enrolled individuals, 172 (29%) had moderate-to-severe WMH. Of these, 18 (10.5%) had Dawson fingers. None had neurological manifestations suggestive of MS. Increasing age was independently associated with Dawson fingers (p = 0.017). Dawson fingers may be less specific for MS than previously thought. Concomitant damage of deep medullary veins may explain the presence of Dawson fingers in cSVD.

The central vein sign in multiple sclerosis patients with vascular comorbidities

Background:

The central vein sign (CVS) is an imaging biomarker able to differentiate multiple sclerosis (MS) from other conditions causing similar appearance lesions on magnetic resonance imaging (MRI), including cerebral small vessel disease (CSVD). However, the impact of vascular risk factors (VRFs) for CSVD on the percentage of CVS positive (CVS+) lesions in MS has never been evaluated.

Objective:

To investigate the association between different VRFs and the percentage of CVS+ lesions in MS.

Methods:

In 50 MS patients, 3T brain MRIs (including high-resolution 3-dimensional T2*-weighted images) were analyzed for the presence of the CVS and MRI markers of CSVD. A backward stepwise regression model was used to predict the combined predictive effect of VRF (i.e. age, hypertension, diabetes, obesity, ever-smoking, and hypercholesterolemia) and MRI markers of CSVD on the CVS.

Results:

The median frequency of CVS+ lesions was 71% (range: 35%–100%). In univariate analysis, age ( p < 0.0001), hypertension ( p < 0.001), diabetes ( p < 0.01), obesity ( p < 0.01), smoking ( p < 0.05), and the presence of enlarged-perivascular-spaces on MRI ( p < 0.005) were all associated with a lower percentage of CVS+ lesions. The stepwise regression model showed that age and arterial hypertension were both associated with the percentage of CVS+ lesions in MS (adjusted R2 = 0.46; p < 0.0001 and p = 0.01, respectively).

Conclusion:

The proportion of CVS+ lesions significantly decreases in older and hypertensive MS patients. Although this study was conducted in patients with an already established MS diagnosis, the diagnostic yield of the previously proposed 35% CVS proportion-based diagnostic threshold appears to be not affected. Overall these results suggest that the presence of VRF for CSVD should be taken into account during the CVS assessment.

BOLD signal within and around white matter lesions distinguishes multiple sclerosis and non-specific white matter disease: a three-dimensional approach

Multiple sclerosis (MS) diagnostic criteria are based upon clinical presentation and presence of white matter hyperintensities on two-dimensional magnetic resonance imaging (MRI) views. Such criteria, however, are prone to false-positive interpretations due to the presence of similar MRI findings in non-specific white matter disease (NSWMD) states such as migraine and microvascular disease. The coexistence of age-related changes has also been recognized in MS patients, and this comorbidity further poses a diagnostic challenge. In this study, we investigated the physiologic profiles within and around MS and NSWMD lesions and their ability to distinguish the two disease states. MS and NSWMD lesions were identified using three-dimensional (3D) T₂-FLAIR images and segmented using geodesic active contouring. A dual-echo functional MRI sequence permitted near-simultaneous measurement of blood-oxygen-level-dependent signal (BOLD) and cerebral blood flow (CBF). BOLD and CBF were calculated within lesions and in 3D concentric layers surrounding each lesion. BOLD slope, an indicator of lesion metabolic capacity, was calculated as the change in BOLD from a lesion through its surrounding perimeters. We observed sequential BOLD signal reductions from the lesion towards the perimeters for MS, while no such decreases were observed for NSWMD lesions. BOLD slope was significantly lower in MS compared to NSWM lesions, suggesting decreased metabolic activity in MS lesions. Furthermore, BOLD signal within and around lesions significantly distinguished MS and NSWMD lesions. These results suggest that this technique shows promise for clinical utility in distinguishing NSWMD or MS disease states and identifying NSWMD lesions occurring in MS patients.

Distinct influence of different vascular risk factors on white matter brain lesions in multiple sclerosis

OBJECTIVE

To determine if vascular risk factor (VRF), that is, smoking, arterial hypertension (HT), dyslipidaemia and diabetes, have an effect on multiple sclerosis (MS) pathology as measured by MS typical brain lesions, we have compared brain MRIs from patients with MS with and without VRF age-matched and sex-matched.

METHODS

Brain MRIs from five centres were scored for the presence of Dawson's fingers (DF) and juxtacortical lesions (JCL). A regression model was built to predict the effect of each individual VRF on DF and JCL, considering age and disease duration.

RESULTS

92 MS cases without VRF and 106 MS with one or more VRF (80 ever-smokers, 43 hypertensives, 25 dyslipidaemics and 10 diabetics) were included. Ever-smoking associated with a higher burden of DF (Exp(B)=1.29, 95% CI 1.10 to 1.51, p<0.01) and JCL (Exp(B)=1.38, 95% CI 1.21 to 1.57, p<0.01). No other VRF had an impact on DF. Dyslipidaemia associated with increased JCL (Exp(B)=1.30, 95% CI 1.10 to 1.56, p<0.01) but HT did not associate with any of the outcomes.

CONCLUSIONS

Individual VRF appear to affect MS-specific lesions differently. An increase in MS lesions was mainly seen in smokers; however, this VRF is most likely to be present from onset of MS, and other VRF effects may be partly mitigated by treatment. Our findings support that treating VRF and cessation of smoking may be important in the management of MS.

[Comorbid pathology of the cardiovascular system in young patients with relapsing-remitting multiple sclerosis]

AIM

To study the state of the cardiovascular system and peripheral microcirculation in young patients with relapsing-remitting multiple sclerosis (MS).

MATERIAL AND METHODS

The study included 45 MS patients (17 men and 28 women, age 28 [24; 32] years, disease duration 5.5 [2; 7] years). The control group included healthy controls (age 30 [25; 33] years). Neurological and cardiologic examinations included 24-hour Holter ECG monitoring and 24-hour blood pressure monitoring with determination of the daily arterial vascular stiffness, echocardiography, laser doppler flowmetry followed by an occlusive test to assess the state of microvasculation, levels of serum vascular cellular adhesion molecule-1 (VCAM-1).

RESULTS

In MS group, the results of 24-hour blood pressure monitoring showed that the variability of systolic blood pressure and diastolic blood pressure during daytime hours was reduced compared to the control group (p<0.026 and p<0.002, respectively). The indicators of daily arterial stiffness in MS group were significantly increased (p<0.001). According to the results of Holter ECG monitoring, no heart rhythm disorder was detected in both groups, except an increase in the number of supraventricular extrasystoles in MS patients compared to the control group (p<0.005). There were no between group differences in echocardiography indicators. The level of VCAM-1 was significantly increased in MS group compared to controls (p<0.001).

CONCLUSION

Young MS patients are at risk of cardiovascular diseases associated with the variability of blood pressure and indexes of daily arterial vascular stiffness.

Melatonin protects blood-brain barrier integrity and permeability by inhibiting matrix metalloproteinase-9 via the NOTCH3/NF-κB pathway

The pathophysiological mechanism of white matter hyperintensities of cerebral small vessel disease (CSVD) includes an impaired blood-brain barrier (BBB) with increased permeability. Neuroinflammation likely contributes to the disruption of the BBB in CSVD. Therefore, understanding the molecular mechanism of how neuroinflammation causes BBB damage is essential to preventing BBB disruption in CSVD. Matrix metalloproteinase 9 (MMP-9) contributes to BBB damage in neuroinflammatory diseases. In this study, we observed that interleukin-1β (IL-1β)-induced MMP-9 secretion in pericytes increased BBB permeability to sodium fluorescein (Na-F) by damaging the disruption of VE-cadherin, occludin, claudin-5, and zonula occludin-1 (ZO-1). Melatonin reduced BBB permeability to Na-F and inhibited the disruption of the adherens and tight junction proteins. Melatonin also downregulated MMP-9 and upregulated tissue inhibitor of metalloproteinases 1 (TIMP-1) gene expression, which decreased the MMP-9/TIMP-1 ratio. In addition, nuclear translocation of NF-κB/p65 induced by IL-1β in pericytes upregulated MMP-9 expression, which was inhibited by the NF-κB inhibitor PDTC. However, the NOTCH3 inhibitor DAPT significantly inhibited NF-κB/p65 translocation to the nucleus, while melatonin in combination with DAPT significantly prevented NF-κB/p65 translocation than DAPT alone. Our results suggest that melatonin reduced MMP-9-induced permeability of the BBB. Melatonin reduced MMP-9 expression and activity, which was induced by IL-1β through the regulation of the NOTCH3/NF-κB signaling pathway in pericytes, suggesting that pericytes regulate BBB integrity and function.

Chronic inflammation in multiple sclerosis - seeing what was always there

Activation of innate immune cells and other compartmentalized inflammatory cells in the brains and spinal cords of people with relapsing-remitting multiple sclerosis (MS) and progressive MS has been well described histopathologically. However, conventional clinical MRI is largely insensitive to this inflammatory activity. The past two decades have seen the introduction of quantitative dynamic MRI scanning with contrast agents that are sensitive to the reduction in blood-brain barrier integrity associated with inflammation and to the trafficking of inflammatory myeloid cells. New MRI imaging sequences provide improved contrast for better detection of grey matter lesions. Quantitative lesion volume measures and magnetic resonance susceptibility imaging are sensitive to the activity of macrophages in the rims of white matter lesions. PET and magnetic resonance spectroscopy methods can also be used to detect contributions from innate immune activation in the brain and spinal cord. Some of these advanced research imaging methods for visualization of chronic inflammation are practical for relatively routine clinical applications. Observations made with the use of these techniques suggest ways of stratifying patients with MS to improve their care. The imaging methods also provide new tools to support the development of therapies for chronic inflammation in MS.

Progression of regional grey matter atrophy in multiple sclerosis

See Stankoff and Louapre (doi:10.1093/brain/awy114) for a scientific commentary on this article.

Grey matter atrophy is present from the earliest stages of multiple sclerosis, but its temporal ordering is poorly understood. We aimed to determine the sequence in which grey matter regions become atrophic in multiple sclerosis and its association with disability accumulation. In this longitudinal study, we included 1417 subjects: 253 with clinically isolated syndrome, 708 with relapsing-remitting multiple sclerosis, 128 with secondary-progressive multiple sclerosis, 125 with primary-progressive multiple sclerosis, and 203 healthy control subjects from seven European centres. Subjects underwent repeated MRI (total number of scans 3604); the mean follow-up for patients was 2.41 years (standard deviation = 1.97). Disability was scored using the Expanded Disability Status Scale. We calculated the volume of brain grey matter regions and brainstem using an unbiased within-subject template and used an established data-driven event-based model to determine the sequence of occurrence of atrophy and its uncertainty. We assigned each subject to a specific event-based model stage, based on the number of their atrophic regions. Linear mixed-effects models were used to explore associations between the rate of increase in event-based model stages, and T₂ lesion load, disease-modifying treatments, comorbidity, disease duration and disability accumulation. The first regions to become atrophic in patients with clinically isolated syndrome and relapse-onset multiple sclerosis were the posterior cingulate cortex and precuneus, followed by the middle cingulate cortex, brainstem and thalamus. A similar sequence of atrophy was detected in primary-progressive multiple sclerosis with the involvement of the thalamus, cuneus, precuneus, and pallidum, followed by the brainstem and posterior cingulate cortex. The cerebellum, caudate and putamen showed early atrophy in relapse-onset multiple sclerosis and late atrophy in primary-progressive multiple sclerosis. Patients with secondary-progressive multiple sclerosis showed the highest event-based model stage (the highest number of atrophic regions, P < 0.001) at the study entry. All multiple sclerosis phenotypes, but clinically isolated syndrome, showed a faster rate of increase in the event-based model stage than healthy controls. T₂ lesion load and disease duration in all patients were associated with increased event-based model stage, but no effects of disease-modifying treatments and comorbidity on event-based model stage were observed. The annualized rate of event-based model stage was associated with the disability accumulation in relapsing-remitting multiple sclerosis, independent of disease duration (P < 0.0001). The data-driven staging of atrophy progression in a large multiple sclerosis sample demonstrates that grey matter atrophy spreads to involve more regions over time. The sequence in which regions become atrophic is reasonably consistent across multiple sclerosis phenotypes. The spread of atrophy was associated with disease duration and with disability accumulation over time in relapsing-remitting multiple sclerosis.

Lifestyle-based modifiable risk factors in multiple sclerosis: review of experimental and clinical findings

Multiple sclerosis (MS) is a lifelong inflammatory and neurodegenerative disease influenced by multiple lifestyle-based factors. We provide a narrative review of the effects of modifiable risk factors that are identified as being associated with risk to develop MS and/or influencing the future clinical disease outcomes. The emerging data regarding the beneficial effects of diet modifications and exercise are further reviewed. In contrast, obesity and comorbid cardiovascular diseases are associated with increased MS susceptibility and worse disease progression. In addition, the potential influence of smoking, coffee and alcohol consumption on MS onset and disability development are discussed. Successful management of the modifiable risk factors may lead to better long-term outcomes and improve patients' quality of life. MS specialists should participate in educating and facilitating lifestyle-based modifications as part of their neurological consults.

Identifying risk factors for cognitive issues in multiple sclerosis

INTRODUCTION

Cognitive impairment (CI) in Multiple Sclerosis (MS) has progressively regained clinical and research interest and is currently recognized as a debilitating and burdensome problem for these patients. Studying risk and protecting factors that may influence the development and course of CI is currently an area of increasing interest, due to the potential for preventive strategies. Areas covered: In this narrative review the authors briefly addressed the physiopathologic basis, assessment and management of CI in MS and then focused on identifying modifiable and not modifiable risk factors for CI in MS, providing an overview of the current knowledge in the field and indicating avenues for future research. Expert opinion: Improving our understanding of potentially modifiable environmental and lifestyle risk factors or protective factors for CI is important in order to prompt preventive strategies and orient patient counselling and clinical management. To this aim, we need to enhance the current level of evidence linking lifestyle factors to cognition and evaluate some factors that were only preliminary addressed in research. Moreover, we need to explore the role of each factor into the subject cognitive outcome, next to the possible interactions between different environmental factors as well as between environmental and genetic factors.

MRI in multiple sclerosis: what is changing?

PURPOSE OF REVIEW

To summarize recent findings from the application of MRI in the diagnostic work-up of patients with suspected multiple sclerosis (MS), and to review the insights into disease pathophysiology and the utility of MRI for monitoring treatment response.

RECENT FINDINGS

New evidence from the application of MRI in patients with clinically isolated syndromes has guided the 2017 revision of the McDonald criteria for MS diagnosis, which has simplified their clinical use while preserving accuracy. Other MRI measures (e.g., cortical lesions and central vein signs) may improve diagnostic specificity, but their assessment still needs to be standardized, and their reliability confirmed. Novel MRI techniques are providing fundamental insights into the pathological substrates of the disease and are helping to give a better understanding of its clinical manifestations. Combined clinical-MRI measures of disease activity and progression, together with the use of clinically relevant MRI measures (e.g., brain atrophy) might improve treatment monitoring, but these are still not ready for the clinical setting.

SUMMARY

Advances in MRI technology are improving the diagnostic work-up and monitoring of MS, even in the earliest phases of the disease, and are providing MRI measures that are more specific and sensitive to disease pathological substrates.

Lower total cerebral arterial flow contributes to cognitive performance in multiple sclerosis patients

BACKGROUND

The cognitive performance in multiple sclerosis (MS) patients declines with aging, longer disease duration, and possibly cardiovascular comorbidities.

OBJECTIVES

We investigated whether lower total cerebral arterial blood flow (CABF) measured at the level of the carotid and vertebral arteries may contribute to worse cognitive performance in 132 MS patients and 47 healthy controls.

METHODS

Total CABF was evaluated with extracranial Doppler, whereas structural T2-lesion volume (LV) and gray matter volume (GMV) were measured on 3T MRI. The cognitive performance was assessed by Symbol Digit Modalities Test (SDMT), Brief Visuospatial Memory Test-Revised (BVMT-R), and California Verbal Learning Test-Second Edition (CVLT-II). Analysis of covariance, partial correlation, and regression models were used to test the differences between study groups and cognition/CABF correlations. False discovery rate (FDR)-corrected (Benjamini-Hochberg) p-values (i.e. q-values) less than 0.05 were considered significant.

RESULTS

Association between lower total CABF and the lower cognitive performance was observed only in MS patients (r = 0.318, q < 0.001 and r = 0.244, q = 0.012 for SDMT and BVMT-R, respectively). Lower GMV, higher T2-LV, and CABF were significantly associated with poorer performance on the processing speed measure of SDMT (adjusted R² = 0.295, t-statistics = 2.538, standardized β = 0.203, and q = 0.020), but not with memory tests. Cognitively impaired MS patients had lower total CABF compared to cognitively preserved (884.5 vs 1020.2 mL/min, q = 0.008).

CONCLUSION

Cognitively impaired MS patients presented with lower total CABF. Altered CABF may be a result of reduced metabolic rate and might contribute to abnormal cognitive aging in MS.

Vascular pathology in multiple sclerosis: reframing pathogenesis around the blood-brain barrier

Blood-brain barrier (BBB) disruption has long been recognised as an important early feature of multiple sclerosis (MS) pathology. Traditionally, this has been seen as a by-product of the myelin-specific immune response. Here, we consider whether vascular changes instead play a central role in disease pathogenesis, rather than representing a secondary effect of neuroinflammation or neurodegeneration. Importantly, this is not necessarily mutually exclusive from current hypotheses. Vascular pathology in a genetically predisposed individual, influenced by environmental factors such as pathogens, hypovitaminosis D and smoking, may be a critical initiator of a series of events including hypoxia, protein deposition and immune cell egress that allows the development of a CNS-specific immune response and the classical pathological and clinical hallmarks of disease. We review the changes that occur in BBB function and cerebral perfusion in patients with MS and highlight genetic and environmental risk factors that, in addition to modulating immune function, may also converge to act on the vasculature. Further context is provided by contrasting these changes with other neurological diseases in which there is also BBB malfunction, and highlighting current disease-modifying therapies that may also have an effect on the BBB. Indeed, in reframing current evidence in this model, the vasculature could become an important therapeutic target in MS.

Investigation of ischemic and demyelinating lesions by cerebral vasoreactivity based on transcranial Doppler sonography: a comparative study

PURPOSE

Variations of cerebral blood flow in response to hypoxia and hyperoxia in different disease conditions can provide new insights into disease etiopathogenesis. This study aimed to determine the characteristics of cerebral vasoreactivity for ischemia and demyelination.

MATERIALS AND METHODS

This case-control study included: 28 patients with lacunar infarctions verified by history, physical examination, and MRI; 28 age- and sex-matched healthy controls; 28 patients with relapsing-remitting multiple sclerosis (MS), based on McDonald criteria; and 28 age- and sex-matched healthy controls for the MS group. Transcranial Doppler sonography was undertaken in all subjects to calculate the mean flow velocity (MFV) of the right middle cerebral artery (MCA) and, after a breath-holding (BH) maneuver, the breath-holding index (BHI) was determined.

RESULTS

There was no significant difference of BHI and changes of MFV of the MCA in MS patients compared to controls (1.02 ± 0.4 vs 1.02 ± 0.3, p = 0.993; and 16.8 ± 8.1 vs 11.3 ± 10.8, p = 0.057). BHI in patients with lacunar infarctions was significantly lower (0.8 ± 0.4 vs 1.2 ± 0.3, p < 0.001) compared to controls. The BHI (p = 0.040) and variations of MFV of MCA (p = 0.007) in MS patients were significantly higher than in patients with lacunar infarctions. The vasoreactivity of demyelinating lesions was higher than that of ischemic ones.

CONCLUSION

Therefore, cerebral vasoreactivity determined by transcranial Doppler could be utilized for differentiating demyelinating from ischemic lesions.

The impact of vascular risk factors on brain volume and lesion load in patients with early multiple sclerosis

BACKGROUND

Vascular risk factors (VRF) in multiple sclerosis (MS) patients have been associated with lower brain volumes. It is currently unknown if this association already exists in early MS and how it develops over time.

METHODS

We identified 82 patients with clinically isolated syndrome (CIS) ( n = 61) or with early relapsing-remitting MS ( n = 21) and assessed their VRF including arterial hypertension, hyperlipidaemia, diabetes mellitus and smoking. We analysed T2-lesion load, normalized brain volume (NBV), cortical grey (cGMV) and white matter volumes (WMV), thalamic and basal ganglia volumes at baseline and follow-up magnetic resonance imaging (MRI) and assessed the percentage of brain volume change (PBVC) using SIENA.

RESULTS

Patient mean age was 32.4 (±8.7) years and 54 (65%) were women. Median follow-up period was 42 (29-54) months. In total, 26 patients (31.7%) had one or more VRF (VRF+). At baseline, VRF+ patients had a lower NBV (1530.9 cm³ vs 1591.2 cm³, p = 0.001), a lower cGMV (628.5 cm³ vs 668.6 cm³, p = 0.002) and WMV (752.2 cm³ vs 783.9 cm³, p = 0.009) than VRF-negative patients. Similar results were obtained at follow-up. PBVC was comparable between patients with and without VRF.

CONCLUSION

VRF are associated with lower brain volume already in early MS but do not lead to increased brain volume loss during 3.5 years of follow-up.

FLAIR* to visualize veins in white matter lesions: A new tool for the diagnosis of multiple sclerosis?

Objective

To explore the potential of a post-processing technique combining FLAIR and T₂* (FLAIR*) to distinguish between lesions caused by multiple sclerosis (MS) from cerebral small vessel disease (SVD) in a clinical setting.

Methods

FLAIR and T₂* head datasets acquired at 3T of 25 people with relapsing MS (pwRMS) and ten with pwSVD were used. After post-processing, FLAIR* maps were used to determine the proportion of white matter lesions (WML) showing the ‘vein in lesion’ sign (VIL), a characteristic histopathological feature of MS plaques. Sensitivity and specificity of MS diagnosis were examined on the basis of >45% VIL⁺ and >60% VIL⁺ WML, and compared with current dissemination in space (DIS) MRI criteria.

Results

All pwRMS had >45% VIL⁺ WML (range 58–100%) whilst in pwSVD the proportion of VIL⁺ WML was significantly lower (0–64%; mean 32±20%). Sensitivity based on >45% VIL⁺ was 100% and specificity 80% whilst with >60% VIL⁺ as the criterion, sensitivity was 96% and specificity 90%. DIS criteria had 96% sensitivity and 40% specificity.

Conclusion

FLAIR* enables VIL⁺ WML detection in a clinical setting, facilitating differentiation of MS from SVD based on brain MRI.

Key points

• FLAIR* in a clinical setting allows visualization of veins in white matter lesions.

• Significant proportions of MS lesions demonstrate a vein in lesion on MRI.

• Microangiopathic lesions demonstrate a lower proportion of intralesional veins than MS lesions.

• Intralesional vein-based criteria may complement current MRI criteria for MS diagnosis.