Venous and cerebrospinal fluid flow in multiple sclerosis: a case-control study

Vascular multiple sclerosis: addressing the pathogenesis, genetics, pro-angiogenic factors, and vascular abnormalities, along with the role of vascular intervention

Dysfunction in the epithelium, breakdown of the blood-brain barrier, and consequent leukocyte and T-cell infiltration into the central nervous system define Vascular Multiple Sclerosis. Multiple sclerosis (MS) affects around 2.5 million individuals worldwide, is the leading cause of neurological impairment in young adults, and can have a variety of progressions and consequences. Despite significant discoveries in immunology and molecular biology, the root cause of MS is still not fully understood, as do the immunological triggers and causative pathways. Recent research into vascular anomalies associated with MS suggests that a vascular component may be pivotal to the etiology of MS, and there can be actually a completely new entity in the already available classification of MS, which can be called 'vascular multiple sclerosis'. Unlike the usual other causes of MS, vascular MS is not dependent on autoimmune pathophysiologic mechanisms, instead, it is caused due to the blood vessels pathology. This review aims to thoroughly analyze existing information and updates about the scattered available findings of genetics, pro-angiogenetic factors, and vascular abnormalities in this important spectrum, the vascular facets of MS.

A case-control study of drinking beverages and the risk of multiple sclerosis in Iran

BACKGROUND

There is no study in the world on the relationship between consuming black and green tea as beverages containing polyphenols and the risk of MS. This study aimed to determine the association between the consumption of green and black tea, coffee, non-alcoholic beer, milk, fruit juices and carbonated beverages with the risk of MS.

METHODS AND MATERIALS

This case-control study was performed on 150 patients with MS and 300 healthy individuals as a control group among patients who were referred to the ophthalmology ward of a referral hospital in Ahvaz with the groups matching for age. The data collection tool was a researcher-made questionnaire including demographic information and beverage consumption. Analysis was performed using univariate and multiple logistic regression models.

RESULTS

The mean age of patients at the time of diagnosis was 38.55 ± 8.88 years. The results showed that drinking milk (OR = 5.46), natural juice (OR = 2.49), and carbonated beverages (OR = 16.17) were associated with an increased chance of developing MS. However, drinking non-alcoholic beer (OR = 0.48), black tea (OR = 0.20), green tea (OR = 0.29) and coffee (OR = 0.07) were associated with a reduced chance of developing MS.

CONCLUSION

The results show that drinking black and green tea, non-alcoholic beer, and coffee are associated with a decrease in the chance of developing MS. The results of this study can be used to design interventional research and to change people's lifestyles to prevent MS.

Flow volume measurement of arterial venous and cerebrospinal fluid in patients with multiple sclerosis

Background Multiple sclerosis (MS) is usually described as an autoimmune disease, although the exact mechanism of the disease remains unknown. There have been studies reporting that venous flow abnormalities may be involved in the pathogenesis of MS or many of the associated clinical manifestations.

Objective The aim of this study was to evaluate flow volumes of the middle cerebral artery (MCA), transverse sinus (TS), and cerebral aqueduct using phase contrast magnetic resonance imaging (PC-MRI) in relapsing-remitting MS patients and a control group.

Methods We included 34 patients diagnosed by the McDonald criteria, revised in 2017, as well as 15 healthy controls matched by age and sex. The MRI scans were performed using a 1.5-T superconducting scanner. Axial T1-weighted, T2-weighted, and PC-MRI sequences were performed for the quantitative investigation of flow volume measurements. Quantitative analyses of flows were performed using flow analyses program PC-MRI angiography software. A circular region of interest was placed manually into the cerebral aqueduct, bilateral MCA, and TS.

Results Flow volumes of the cerebral aqueduct and MCA were not statistically significant between the MS and control groups. The flow volumes of the TS for the patient group were lower than those of the control group, and this difference was statistically significant.

Conclusions A reduced TS flow volume in MS patients was noted in the present study when compared with the control group, suggesting a relation between venous pathologies and MS. Further studies are needed to understand whether this relation is causal or epiphenomenal.

4D flow MRI hemodynamic biomarkers for cerebrovascular diseases

Alterations in cerebral blood flow are common in several neurological diseases among the elderly including stroke, cerebral small vessel disease, vascular dementia, and Alzheimer's disease. 4D flow magnetic resonance imaging (MRI) is a relatively new technique to investigate cerebrovascular disease, and makes it possible to obtain time-resolved blood flow measurements of the entire cerebral arterial venous vasculature and can be used to derive a repertoire of hemodynamic biomarkers indicative of cerebrovascular health. The information that can be obtained from one single 4D flow MRI scan allows both the investigation of aberrant flow patterns at a focal location in the vasculature as well as estimations of brain-wide disturbances in blood flow. Such focal and global hemodynamic biomarkers show the potential of being sensitive to impending cerebrovascular disease and disease progression and can also become useful during planning and follow-up of interventions aiming to restore a normal cerebral circulation. Here, we describe 4D flow MRI approaches for analyzing the cerebral vasculature. We then survey key hemodynamic biomarkers that can be reliably assessed using the technique. Finally, we highlight cerebrovascular diseases where one or multiple hemodynamic biomarkers are of central interest.

Quantified hemodynamic parameters of the venous system in multiple sclerosis: A systematic review

BACKGROUND

Multiple Sclerosis (MS) is a complex neurodegenerative condition that is influenced by a combination of genetic and environmental factors. Included in these factors is the venous system, however, the extent to which it influences the etiology of MS has yet to be fully characterised. The aim of this review is to critically summarize the literature available concerning the venous system in MS, primarily concerning specific data on the venous pressure and blood flow in this system.

METHODS

A systematic review was conducted with the application of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. The advanced search functions of both the Scopus and PubMed databases were used to conduct the literature search, resulting in 136 unique articles initially identified. Applying relevant exclusion criteria, 22 of the studies were chosen for this review.

RESULTS

The selected studies were analysed for venous pressure and blood flow related findings, with 14 studies contributing data on the internal jugular vein (IJV) flow rate, 5 on blood flows of the intracranial venous sinuses, 2 on blood flow pulsatility and 6 supplying information relevant to the venous pressure (3 studies contributed to multiple areas). The general findings of the review included that the IJV flow was not significantly different between MS patients and controls, however, there were variances between stenotic (S) and non-stenotic (NS) MS patients. Due to the limited data in the other two areas defined in this review, further research is required to establish if any variances in MS are present.

CONCLUSION

It remains unclear if there are significant differences in many flow variables between MS patients and controls considered in this review. It would be advantageous if future work in this area focused on understanding the hemodynamics of this system, primarily concerning how the flow rate, venous pressure and vascular resistance are related, and any impact that these factors have on the etiology of MS.

Clinical characteristics, inflammation and coagulation status in patients with immunological disease-related chronic cerebrospinal venous insufficiency

Background

Immunological disease-related chronic cerebrospinal venous insufficiency (CCSVI) is rarely reported. This study aimed to analyze clinical characteristics, inflammation, and coagulation status in patients with immunological disease-related CCSVI.

Methods

Patients with CCSVI were enrolled from 2017 to 2019 and divided into three cohorts based on their immunological disease backgrounds, including groups with confirmed autoimmune disease, with suspected/subclinical autoimmune disease, and with non-immunological etiology. Immunological, inflammatory, and thrombophilia biomarker assay in blood samples were obtained. Mann-Whitney U test or Fisher’s exact test was used to compare continuous variables or categorical variables between the CCSVI patients with or without the immunological etiology. Spearman’s correlation analysis was conducted among age, baseline neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), interleukin-6 (IL-6), C-reactive protein (CRP), and neuron-specific enolase (NSE) in the three groups.

Results

A total of 255 consecutive patients with CCSVI were enrolled, including three subgroups: CCSVI with confirmed autoimmune disease (n=41), CCSVI with suspected/subclinical autoimmune disease (n=116) and CCSVI with non-immunological etiology (n=98). In the first subgroup, a series of 41 cases was confirmed with eight different autoimmune diseases including antiphospholipid syndrome (n=18), Sjögren’s syndrome (n=8), immunoglobulin G4-related disease (n=7), Behçet’s disease (n=2), autoimmune hepatitis (n=2), Wegener's granulomatosis (n=2), systemic sclerosis (n=1) and AQP4 antibody-positive neuromyelitis optica spectrum disorder (n=1). Groups with immunological etiology did not show a higher incidence of thrombophilia or increased pro-inflammatory biomarkers (e.g., neutrophil, IL-6). However, patients with non-immunological etiology had a higher baseline level of CRP. Additionally, baseline PLR was moderately correlated to NLR and CRP in CCSVI patients with non-immunological etiology and suspected/subclinical autoimmune disease.

Conclusions

The formation of CCSVI may be based on the inflammatory process, facilitated by multiple risk factors, among which medical history of immunological diseases may play a significant role due to the intricate relationship between inflammation and coagulation. Moreover, CCSVI may also cause an independent inflammatory injury in venous walls, leading to focal stenosis or thrombus, without attacks from autoimmune antibodies.

Longitudinal analysis of cerebral aqueduct flow measures: multiple sclerosis flow changes driven by brain atrophy

Background

Several small cross-sectional studies have investigated cerebrospinal fluid (CSF) flow dynamics in multiple sclerosis (MS) patients and have reported mixed results. Currently, there are no longitudinal studies that investigate CSF dynamics in MS patients.

Objective

To determine longitudinal changes in CSF dynamics measured at the level of aqueduct of Sylvius (AoS) in MS patients and matched healthy controls (HCs).

Materials and methods

Forty (40) MS patients and 20 HCs underwent 3T MRI cine phase contrast imaging with velocity-encoded pulse-gated sequence at baseline and 5-year follow-up. For atrophy determination, MS patients underwent additional high-resolution 3D T1-weighted imaging. Measures of AoS cross-sectional area (CSA), average systolic and diastolic velocity peaks, maximal systolic and diastolic velocity peaks and average CSF flow rates were determined. Brain atrophy and ventricular CSF (vCSF) expansion rates were determined. Cross-sectional and longitudinal changes were derived by analysis of covariance (ANCOVA) and paired repeated tests. Confirmatory general linear models were also performed. False discovery rate (FDR)-corrected p-values lower than 0.05 were considered significant.

Results

The MS population demonstrated significant increase in maximal diastolic peak (from 7.23 to 7.86 cm/s, non-adjusted p = 0.037), diastolic peak flow rate (7.76 ml/min to 9.33 ml/min, non-adjusted p = 0.023) and AoS CSA (from 3.12 to 3.69 mm², adjusted p = 0.001). The only differentiator between MS patients and HCs was the greater AoS CSA (3.58 mm² vs. 2.57 mm², age- and sex-adjusted ANCOVA, p = 0.045). The AoS CSA change was associated with vCSF expansion rate (age- and sex-adjusted Spearman’s correlation r = 0.496, p = 0.019) and not with baseline nor change in maximal velocity. The expansion rate of the vCSF space explained an additional 23.8% of variance in change of AoS CSA variance when compared to age and sex alone (R² = 0.273, t = 2.557, standardized β = 0.51, and p = 0.019).

Conclusion

MS patients present with significant longitudinal AoS enlargement, potentially due to regional atrophy changes and ex-vacuo expansion of the aqueduct.

Percutaneous transluminal angioplasty for treatment of chronic cerebrospinal venous insufficiency (CCSVI) in people with multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is a leading cause of neurological disability in young adults. The most widely accepted hypothesis regarding its pathogenesis is that it is an immune-mediated disease. It has been hypothesised that intraluminal defects, compression, or hypoplasia in the internal jugular or azygos veins may be important factors in the pathogenesis of MS. This condition has been named 'chronic cerebrospinal venous insufficiency' (CCSVI). It has been suggested that these intraluminal defects restrict the normal blood flow from the brain and spinal cord, causing the deposition of iron in the brain and the eventual triggering of an auto-immune response. The proposed treatment for CCSVI is venous percutaneous transluminal angioplasty (PTA), which is claimed to improve the blood flow in the brain thereby alleviating some of the symptoms of MS. This is an update of a review first published in 2012.

OBJECTIVES

To assess the benefit and safety of venous PTA in people with MS and CCSVI.

SEARCH METHODS

We searched the Cochrane Multiple Sclerosis and Rare Diseases of the Central Nervous System Group's Specialised Register up to 30 August 2018, CENTRAL (in the Cochrane Library 2018, issue 8), MEDLINE up to 30 August 2018, Embase up to 30 August 2018, metaRegister of Controlled Trials, ClinicalTrials.gov., the Australian New Zealand Clinical Trials Registry, and the World Health Organization (WHO) International Clinical Trials Registry platform. We examined the bibliographies of the included and excluded studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in which PTA and sham interventions were compared in adults with MS and CCSVI.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility and risk of bias, and extracted data. We reported results as risk ratios (RR) with 95% confidence intervals (CI). We performed statistical analyses using the random-effects model; and we assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We included three RCTs (238 participants) in this update. One hundred and thirty-four participants were randomised to PTA and 104 to sham treatment. We attributed low risk of bias to two (67%) studies for sequence generation and two (67%) studies for performance bias. All studies were at a low risk of detection bias, attrition bias, reporting bias and other potential sources of bias.There was moderate-quality evidence to suggest that venous PTA did not increase the proportion of patients who had operative or post-operative serious adverse events compared with the sham procedure (RR 3.33, 95% CI 0.36 to 30.44; 3 studies, 238 participants); nor did it increase the proportion of patients who improved on a functional composite measure including walking control, balance, manual dexterity, postvoid residual urine volume, and visual acuity over 12-month follow-up (RR 0.84, 95% CI 0.55 to 1.30; 1 study, 110 participants); nor did it reduce the proportion of patients who experienced new relapses at six- or 12-month follow-up (RR 0.87, 95% CI 0.51 to 1.49; 3 studies, 235 participants). There was no effect of venous PTA on disability worsening measured by the Expanded Disability Status Scale, which was reported at follow-up intervals of six months (one study), 11 months (one study) and 12 months (one study). Quality of life was reported in two studies with no difference between treatment groups. Moderate or severe pain during or post venography was reported in both PTA and sham-procedure participants in all included studies. Venous PTA was not effective in restoring blood flow assessed at one-month (one study) or 12-month follow-up (one study).

AUTHORS' CONCLUSIONS

This systematic review identified moderate-quality evidence that, compared with sham procedure, venous PTA intervention did not provide benefit on patient-centred outcomes (disability, physical or cognitive functions, relapses, quality of life) in people with MS. Venous PTA has proven to be a safe technique but in view of the available evidence of its ineffectiveness, this intervention cannot be recommended in people with MS. All ongoing trials were withdrawn or terminated and hence this updated review is conclusive. No further randomised clinical studies are needed.

Hemodynamics of cerebral veins analyzed by 2d and 4d flow mri and ultrasound in healthy volunteers and patients with multiple sclerosis

BACKGROUND

Hemodynamic alterations of extracranial veins are considered an etiologic factor in multiple sclerosis (MS). However, ultrasound and MRI studies could not confirm a pathophysiological link. Because of technical challenges using standard diagnostics, information about the involvement of superficial intracranial veins in proximity to the affected brain in MS is scarce.

PURPOSE

To comprehensively investigate the hemodynamics of intracranial veins and of the venous outflow tract in MS patients and controls.

STUDY TYPE

Prospective.

POPULATION

Twenty-eight patients with relapsing-remitting MS (EDSS1.9 ± 1.1; range 0-3) and 41 healthy controls.

FIELD STRENGTH/SEQUENCE

3T/2D phase-contrast and time-resolved 4D flow MRI, extra- and transcranial sonography.

ASSESSMENT

Hemodynamics within the superficial and deep intracranial venous system and outflow tract including the internal, basal, and great cerebral vein, straight, superior sagittal, and transverse sinuses, internal jugular and vertebral veins. Sonography adhered to the chronic cerebrospinal venous insufficiency (CCSVI) criteria.

STATISTICAL TESTS

Multivariate repeated measure analysis of variance, Student's two-sample t-test, chi-square, Fisher's exact test; separate analysis of the entire cohort and 32 age- and sex-matched participants.

RESULTS

Multi- and univariate main effects of the factor group (MS patient vs. control) and its interactions with the factor vessel position (lower flow within dorsal superior sagittal sinus in MS, 3 ± 1 ml/s vs. 3.8 ± 1 ml/s; P < 0.05) in the uncontrolled cohort were attributable to age-related differences. Age- and sex-matched pairs showed a different velocity gradient in a single segment within the deep cerebral veins (great cerebral vein, vena cerebri magna [VCM] 7.6 ± 1.7 cm/s; straight sinus [StS] 10.5 ± 2.2 cm/s vs. volunteers: VCM 9.2 ± 2.3 cm/s; StS 10.2 ± 2.3 cm/s; P = 0.01), reaching comparable velocities instantaneously downstream. Sonography was not statistically different between groups.

DATA CONCLUSION

Consistent with previous studies focusing on extracranial hemodynamics, our comprehensive analysis of intracerebral venous blood flow did not reveal relevant differences between MS patients and controls. Level of Evidence 1. Technical Efficacy Stage 3. J. Magn. Reson. Imaging 2020;51:205-217.

Assessing test-retest reliability of phase contrast MRI for measuring cerebrospinal fluid and cerebral blood flow dynamics

PURPOSE

Pathological states occur when cerebrospinal fluid (CSF) and cerebral blood flow (CBF) dynamics become dysregulated in the brain. Phase-contrast MRI (PC-MRI) is a noninvasive imaging technique that enables quantitative measurements of CSF and CBF flow. While studies have validated PC-MRI as an imaging technique for flow, few studies have evaluated its reliability for CSF and CBF flow parameters commonly associated with neurological disease. The purpose of this study was to evaluate test-retest reliability at the cerebral aqueduct (CA) and C2-C3 area using PC-MRI to assess the feasibility of investigating CSF and CBF flow dynamics.

METHODS

This study was performed on 27 cognitively normal young adults (ages 20-35 years). Flow data was acquired on a 3T Siemens Prisma using a 2D cine-PC pulse sequence. Three consecutive flow measurements were acquired at the CA and C2-C3 area. Intraclass correlation coefficient (ICC) and coefficient of variance (CV) were used to evaluate intrarater, inter-rater, and test-retest reliability.

RESULTS

Among the 26 flow parameters analyzed, 22 had excellent reliability (ICC > 0.80), including measurements of CSF stroke volume, flush peak, and fill peak, and 4 parameters had good reliability (ICC 0.60-0.79). 16 flow parameters had a mean CV ≤ 10%, 7 had a CV ≤ 15%, and 3 had a CV ≤ 30%. All CSF and CBF flow measurements had excellent inter-rater and intrarater reliability (ICC > 0.80).

CONCLUSION

This study shows that CSF and CBF flow can be reliably measured at the CA and C2-C3 area using PC-MRI, making it a promising tool for studying flow dynamics in the central nervous system.

Environmental Risk Factors for Multiple Sclerosis: A Case-control Study in Kerman, Iran

BACKGROUND

Several studies have addressed the environmental risk factors for multiple sclerosis (MS). Concerning contradictory results and change of epidemiologic patterns and the role of environmental factors, in the present study, some risk factors, especially environmental factors, on MS were studied.

MATERIALS AND METHODS

This was a retrospective case-control study conducted among 120 patients with MS and 360 healthy individuals in Kerman, Iran. Inclusion criteria included (1) MS disease, diagnosed by a neurologist according to the McDonald criteria, and (2) tendency to participation in the study. Exclusion criteria included (1) suffering from cognitive disorders; (2) incomplete questionnaire; and (3) continuous migration. Data were collected using a questionnaire consisting of personal information and some environmental factors. Data were analyzed using descriptive and inferential statistics.

RESULTS

The results showed that diet was associated with a higher risk of MS with the odds ratio (OR) of 14.46 and 95% confidence interval (CI) of 3.02-69.21 (p < 0.001) for vegetarian and OR of 11.74, 95% CI of 4.66-29.57 (p < 0.001) for animal diets. Similarly, vitamin D supplementation contributed to MS risk (OR: 2.27, 95% CI: 1.32-3.89; p < 0.001). In contrast, history of using cow's milk during infancy resulted in a lower risk of MS (OR: 0.33, 95% CI: 0.20-0.52, p < 0.001).

CONCLUSIONS

This study suggests that different lifestyles including using cow's milk during infancy and avoiding only vegetarian and animal diets may reduce MS risk in southeastern Iran. More studies are suggested to investigate the controversial finding of the negative effect of vitamin D supplementation in this area.

Cerebrospinal Fluid Dynamics in Patients with Multiple Sclerosis: The Role of Phase-Contrast MRI in the Differential Diagnosis of Active and Chronic Disease

Objective

Multiple sclerosis (MS) is an inflammatory disease characterized by demyelinating plaques in the white matter. Chronic cerebrospinal venous insufficiency (CCSVI) has been proposed as a new hypothesis for the etiopathogenesis of MS disease. MS-CCSVI includes a significant decrease of cerebrospinal fluid (CSF) flow through the cerebral aqueduct secondary to an impaired venous outflow from the central nervous system. This study aimed to determine whether CSF flow dynamics are affected in MS patients and the contributions to differential diagnosis in active and chronic disease using phase-contrast magnetic resonance imaging (PC-MRI).

Materials and Methods

We studied 16 MS patients with chronic plaques (group 1), 16 MS patients with active plaques-enhanced on MRI (group 2), and 16 healthy controls (group 3). Quantitatively evaluation of the CSF flow was performed from the level of the cerebral aqueduct by PC-MRI. According to heart rates, 14-30 images were obtained in a cardiac cycle. Cardiac triggering was performed prospectively using finger plethysmography.

Results

No statistically significant difference was found between the groups regarding average velocity, net forward volume and the average flow (p > 0.05). Compared with the controls, group 1 and group 2, showed a higher peak velocity (5.5 ± 1.4, 4.9 ± 1.0, and 4.3 ± 1.3 cm/sec, respectively; p = 0.040), aqueductal area (5.0 ± 1.3, 4.1 ± 1.5, and 3.1 ± 1.2 mm², respectively; p = 0.002), forward volume (0.039 ± 0.016, 0.031 ± 0.013, and 0.021 ± 0.010 mL, respectively; p = 0.002) and reverse volume (0.027 ± 0.016, 0.018 ± 0.009, and 0.012 ± 0.006 mL, respectively; p = 0.000). There were no statistical significance between the MS patients with chronic plaques and active plaques except for reverse volume. The MS patients with chronic plaques showed a significantly higher reverse volume (p = 0.000).

Conclusion

This study indicated that CSF flow is affected in MS patients, contrary to the hypothesis that CCSVI-induced CSF flow decreases in MS patients. These findings may be explained by atrophy-dependent ventricular dilatation, which may occur at every stage of MS.

Four-dimensional flow magnetic resonance imaging and ultrasound assessment of cerebrospinal venous flow in multiple sclerosis patients and controls

A possibly causal relationship between multiple sclerosis and chronic cerebrospinal venous insufficiency has recently been hypothesized. Studies investigating chronic cerebrospinal venous insufficiency have reported conflicting results and few have employed multiple diagnostic imaging modalities across a large patient and control population. In this study, three complementary imaging modalities were used to investigate the chronic cerebrospinal venous insufficiency hypothesis in patients with multiple sclerosis and two age- and sex-matched control groups: healthy volunteers and patients with other neurological diseases. Strictly blinded Doppler ultrasound according to the original chronic cerebrospinal venous insufficiency hypothesis; four-dimensional flow magnetic resonance imaging of venous flow in the head, neck, and chest; and contrast-enhanced magnetic resonance venography for neck and chest venous luminography were acquired. An internal jugular vein stenosis evaluation was also performed across modalities. Percentage of subjects meeting ultrasound-based chronic cerebrospinal venous insufficiency criteria was small and similar between groups. In group-wise and pairwise testing, no four-dimensional flow magnetic resonance imaging variables were statistically significantly different, for any measurement location. In contrast-enhanced magnetic resonance venography of the internal jugular and azygos veins, no statistically significant differences were observed in stenosis scores between groups. These results represent compelling evidence against the chronic cerebrospinal venous insufficiency hypothesis in multiple sclerosis.

Use of Phase-Contrast MRA to Assess Intracranial Venous Sinus Resistance to Drainage in Healthy Individuals

BACKGROUND AND PURPOSE

Resistance to blood flow in the cerebral drainage system may affect cerebral hemodynamics. The objective of the present study was to use phase-contrast MRA to quantify resistance to drainage of blood across branches of the venous sinus tree and to determine whether the resistance to drainage values correlated with internal jugular vein outflows.

MATERIALS AND METHODS

We performed whole-head phase-contrast MRA and 2D phase-contrast MR imaging in 31 healthy volunteers. Vascular segmentation was applied to the angiograms, and the internal jugular vein velocities were quantified from the flow images. Resistance to drainage across branches of the venous sinus tree was calculated from the segmented angiograms, by using the Poiseuille equation for laminar flow. Correlations between the values of resistance to drainage and internal jugular vein outflow measurements were assessed by using the Spearman ρ.

RESULTS

The overall mean resistance to drainage of the venous sinus tree was 24 ± 7 Pa s/cm³. The mean resistance to drainage of the right side of the venous sinus tree was 42% lower than that of the left side (P < .001). There were negative correlations between the values of resistance to drainage and internal jugular vein outflows on both the left side of the venous sinus tree (R = -0.551, P = .002) and the right side (R = -0.662, P < .001).

CONCLUSIONS

Phase-contrast MRA is a noninvasive means of calculating the resistance to drainage of blood across the venous sinus tree. Our approach for resistance to drainage quantification may be of value in understanding alterations in the cerebral venous sinus drainage system.

The manifestation of vortical and secondary flow in the cerebral venous outflow tract: An in vivo MR velocimetry study

Aberrations in flow in the cerebral venous outflow tract (CVOT) have been implicated as the cause of several pathologic conditions including idiopathic intracranial hypertension (IIH), multiple sclerosis (MS), and pulsatile tinnitus (PT). The advent of 4D flow magnetic resonance imaging (4D-flow MRI) has recently allowed researchers to evaluate blood flow patterns in the arterial structures with great success. We utilized similar imaging techniques and found several distinct flow characteristics in the CVOT of subjects with and without lumenal irregularities. We present the flow patterns of 8 out of 38 subjects who have varying heights of the internal jugular bulb and varying lumenal irregularities including stenosis and diverticulum. In the internal jugular vein (IJV) with an elevated jugular bulb (JB), 4Dflow MRI revealed a characteristic spiral flow that was dependent on the level of JB elevation. Vortical flow was also observed in the diverticula of the venous sinuses and IJV. The diversity of flow complexity in the CVOT illustrates the potential importance of hemodynamic investigations in elucidating venous pathologies.

Lack of correlation between extracranial venous abnormalities and multiple sclerosis: a quantitative MRI study

OBJECTIVE:

We aimed to evaluate the presence of venous stenosis and blood flow abnormalities in the neck vessels of patients with multiple sclerosis (MS), in respect to a group of age- and sex-matched healthy controls (HC), and their possible relations with clinical variables using a semi-automated quantitative MRI method.

METHODS:

45 patients with relapsing remitting MS and 40 HC were enrolled in this study. Flow rates and cross-sectional areas of arterial and venous neck vessels were assessed by phase-contrast MRI at two different neck levels (C2-C3 and C6-C7), and differences between groups were evaluated with an unpaired t-test. Correlation between blood flow variables and clinical parameters was analyzed with Spearman's test.

RESULTS:

A significant internal jugular vein (IJV) stenosis was found in 23/45 (51.1%) patients with MS and 18/40 (45.0%) HC. No differences were observed between patients with MS and HC for any of the flow measures obtained. No correlations were found between MRI measures and any of the tested clinical variables.

CONCLUSION:

No differences in the IJV area emerged at quantitative MRI evaluation, suggesting that stenosis of the extracranial veins is unrelated to MS. Furthermore, no flow differences in the neck vessels were found between patients with MS and HC in any of the tested flow measures, with no correlation with clinical variables. Our results confirm that the hypothesis of the presence of extracranial venous abnormalities in MS, both in terms of stenosis or flow measures, is not suitable.

ADVANCES IN KNOWLEDGE:

Neck venous drainage abnormalities have been claimed to be associated with MS. Conversely, our quantitative MRI analysis seems to exclude that extracranial venous alterations are related to the disease.

Extracranial Venous abnormalities: A true pathological finding in patients with multiple sclerosis or an anatomical variant?

OBJECTIVE

To evaluate the extracranial venous anatomy with contrast-enhanced MR venogram (CE-MRV) in patients without multiple sclerosis (MS), and assess the prevalence of various venous anomalies such as asymmetry and stenosis in this population.

MATERIALS AND METHODS

We prospectively recruited 100 patients without MS, aged 18-60 years, referred for contrast-enhanced MRI. They underwent additional CE-MRV from skull base to mediastinum on a 3T scanner. Exclusion criteria included prior neck radiation, neck surgery, neck/mediastinal masses or significant cardiac or pulmonary disease. Two neuroradiologists independently evaluated the studies to document asymmetry and stenosis in the jugular veins and prominence of collateral veins.

RESULTS

Asymmetry of internal jugular veins (IJVs) was found in 75 % of subjects. Both observers found stenosis in the IJVs with fair agreement. Most stenoses were located in the upper IJV segments. Asymmetrical vertebral veins and prominence of extracranial collateral veins, in particular the external jugular veins, was not uncommon.

CONCLUSION

It is common to have stenoses and asymmetry of the IJVs as well as prominence of the collateral veins of the neck in patients without MS. These findings are in contrast to prior reports suggesting collateral venous drainage is rare except in MS patients.

KEY POINTS

• The venous anatomy of the neck in patients without MS demonstrates multiple variants • Asymmetry and stenoses of the internal jugular veins are common • Collateral neck veins are not uncommon in patients without MS • These findings do not support the theory of chronic cerebrospinal venous insufficiency • MR venography is a useful imaging modality for assessing venous anatomy.

Effects of short-term exposure to head-down tilt on cerebral hemodynamics: a prospective evaluation of a spaceflight analog using phase-contrast MRI

Alterations in cerebral hemodynamics in microgravity are hypothesized to occur during spaceflight and could be linked to the Visual Impairment and Intracranial Pressure syndrome. Head-down tilt (HDT) is frequently used as a ground-based analog to simulate cephalad fluid shifts in microgravity; however, its effects on cerebral hemodynamics have not been well studied with MRI techniques. Here, we evaluate the effects of 1) various HDT angles on cerebral arterial and venous hemodynamics; and 2) exposure to 1% CO2 during an intermediate HDT angle (-12°) as an additional space-related environmental factor. Blood flow, cross-sectional area (CSA), and blood flow velocity were measured with phase-contrast MRI in the internal jugular veins, as well as the vertebral and internal carotid arteries. Nine healthy male subjects were measured at baseline (supine, 0°) and after 4.5 h of HDT at -6°, -12° (with and without 1% CO2), and -18°. We found a decrease in total arterial blood flow from baseline during all angles of HDT. On the venous side, CSA increased with HDT, and outflow decreased during -12° HDT (P = 0.039). Moreover, the addition of 1% CO2 to -12° HDT caused an increase in total arterial blood flow (P = 0.016) and jugular venous outflow (P < 0.001) compared with -12° HDT with ambient atmosphere. Overall, the results indicate decreased cerebral blood flow during HDT, which may have implications for microgravity-induced cerebral hemodynamic changes.

Variability in the Cross-Sectional Area and Narrowing of the Internal Jugular Vein in Patients Without Multiple Sclerosis

OBJECTIVE

Chronic cerebrospinal vascular insufficiency is a proposed condition of intraluminal stenosis of the internal jugular vein (IJV) that impedes venous flow from the brain. Calculations of IJV stenosis are vague and described in veins with at least a 50% reduction in IJV caliber at a specific level. The purpose of this study was to assess normal changes in anatomic caliber of the course of the IJV in a generalized population.

MATERIALS AND METHODS

Images from 500 consecutive contrast-enhanced neck CT studies performed in January-July 2011 were reviewed. Cross-sectional areas of the IJV were calculated at the jugular foramen, C1-C7 levels, and jugular angles bilaterally. Patients were excluded if they had severely motion-limited studies; limited clinical data; a history of multiple sclerosis, neck mass, or neck dissection; or known IJV occlusion. Normalized IJV cross-sectional areas at each level were compared with an averaged normalized cross-sectional area from all patients at each level.

RESULTS

Greater than 50% narrowing compared with a normalized average was found in 133 of 363 patients (36.6%) and was seen at all IJV levels. In 36.1% of patients this narrowing occurred at the C1 level. Most of the areas of narrowing greater than 50% occurred above the C4 level.

CONCLUSION

The IJV has marked variability in its course in the neck. Areas of narrowing greater than 50% occur most commonly in the upper cervical and skull base regions. Given the normal anatomic variations in IJV caliber, caution should be used when making the diagnosis of and treating IJV stenosis.

Medical Tourism for CCSVI Procedures in People with Multiple Sclerosis: An Observational Study

BACKGROUND

Many Canadians with multiple sclerosis (MS) have recently travelled internationally to have procedures for a putative condition called chronic cerebrospinal venous insufficiency (CCSVI). Here, we describe where and when they went and describe the baseline characteristics of persons with MS who participated in this non-evidence-based medical tourism for CCSVI procedures.

METHODS

We conducted a longitudinal observational study that used online questionnaires to collect patient-reported information about the safety, experiences, and outcomes following procedures for CCSVI. A convenience sample of all Albertans with MS was recruited between July 2011 and March 2013.

RESULTS

In total, 868 individuals enrolled; 704 were included in this cross-sectional, baseline analysis. Of these, 128 (18.2%) participants retrospectively reported having procedures for CCSVI between April 2010 and September 2012. The proportion of participants reporting CCSVI procedures declined from 80 (62.5%) in 2010, to 40 (31.1%) in 2011, and 8 (6.3%) in 2012. In multivariable logistic regression analysis, CCSVI procedures were independently associated with longer disease duration, secondary progressive clinical course, and greater disability status.

CONCLUSIONS

Although all types of people with MS pursued procedures for CCSVI, a major driver of participation was greater disability. This highlights that those with the greatest disability are the most vulnerable to unproven experimental procedures. Participation in CCSVI procedures waned over time possibly reflecting unmet expectations of treated patients, decreased media attention, or that individuals who wanted procedures had them soon after the CCSVI hypothesis was widely publicized.

Jugular Venous Flow Abnormalities in Multiple Sclerosis Patients Compared to Normal Controls

BACKGROUND

To determine if extracranial venous structural and flow abnormalities exist in patients with multiple sclerosis (MS).

METHODS

Magnetic resonance imaging was used to assess the anatomy and function of major veins in the neck in 138 MS patients and 67 healthy controls (HC). Time-of-flight MR angiography (MRA) was used to assess stenosis while 2-dimensional phase-contrast flow quantification was used to assess flow at the C2/C3 and C5/C6 levels. Venous flow was normalized to the total arterial flow. The MS patients were divided into stenotic (ST) and nonstenotic (NST) groups based on MRA assessment, and each group was compared to the HC group in anatomy and flow.

RESULTS

The MS group showed lower normalized internal jugular vein (IJV) blood flow (tIJV/tA) than the HC group (P < .001). In the MS group, 72 (52%) were classified as ST while 66 (48%) were NST. In the HC group, 11 (23%) were ST while 37 (77%) were NST. The ST-MS group had lower IJV flow than both HC and NST-MS groups.

CONCLUSION

After categorizing the MS population into two groups based upon anatomical stenosis, as determined from an absolute quantification of IJV cross section, clear differences in IJV flow between the ST-MS and HC samples became evident. Despite the unknown etiology of MS, abnormal venous flow was noted in a distinct group of MS patients compared to HC.

Transvascular autonomic modulation: a modified balloon angioplasty technique for the treatment of autonomic dysfunction in multiple sclerosis patients

PURPOSE

To describe the use of transvascular autonomic modulation (TVAM) to improve cardiovascular autonomic nervous system (ANS) dysfunction in multiple sclerosis (MS) patients, comparing the safety and efficacy of this modified technique with traditional balloon angioplasty.

METHODS

Twenty-one MS patients (11 men; mean age 48.7±13.0 years) who presented with symptoms of cardiovascular ANS dysfunction underwent TVAM. These patients were compared with age/sex-matched MS patients (10 men; 49.3±11.1 years) in the same stages of the disease who presented with chronic cerebrospinal venous insufficiency (CCSVI) and who underwent venous balloon angioplasty. TVAM involved the coupling of balloon angioplasty of the internal jugular veins with the application of external manual compression and dilation of the azygos and renal veins; unlike traditional angioplasty for CCSVI, which treats only abnormal veins (≥50% stenosis or static valve), all targeted vessels were treated with TVAM regardless of the presence of an abnormality. The effect of TVAM on ANS function was indicated by determining heart rate variability based on the electrocardiographic R-R interval lengths using vector analysis to derive the mean circular resultant (MCR) and the expiration/inspiration (E/I) ratio, the Valsalva ratio, and the 30:15 postural ratio at 24 hours after intervention.

RESULTS

Left renal vein compression was common among the TVAM patients and resulted in ≥50% luminal compromise in 10 of 21 patients. Azygos vein abnormalities (a static valve) were identified in 5 patients. Overall, 18 patients met the diagnostic criteria for CCSVI with at least one lesion >50%, but only 10 lesions were considered treatable by traditional balloon angioplasty. After intervention, the R-R interval values, including the 30:15 postural ratio (p=0.01), the MCR (p=0.1), and E/I ratio (p=0.1), were higher for the TVAM patients compared to the control group. The safety profile of the TVAM procedure was similar to that of traditional balloon angioplasty.

CONCLUSION

The combination of balloon angioplasty of anatomically normal veins coupled with external compression during dilation of these veins can improve indicators of ANS dysfunction. The safety and efficacy of TVAM in MS patients observed in this pilot study is encouraging, paving the way for the treatment of dysautonomia in pathological states other than MS. Further studies should investigate TVAM in a larger MS cohort.

Dynamic Cerebrospinal Fluid Flow on MRI in Cortical Cerebellar Atrophy and Multiple System Atrophy-cerebellar Type

OBJECTIVE

The purpose of this study was to examine a new MRI technology, dynamic cerebrospinal fluid (CSF) flow, to examine sporadic cerebellar ataxia patients with cortical cerebellar atrophy (CCA) and multiple system atrophy-cerebellar type (MSA-C).

METHODS

Nine CCA patients (3 men and 6 women; mean age: 64.2±6.9 years) and 31 MSA-C patients (13 men and 18 women; mean age: 62.7±6.8 years) were examined by a dynamic CSF flow analysis. All CSF flow data were evaluated by phase contrast-MRI using a 1.5T MRI scanner. The CSF flow was calculated by 15 images in the equidistant MRI sequence which was taken through a cardiac cycle.

RESULTS

Compared with the CCA patients, the absolute values of the mean velocity of the MSA-C patients were significantly reduced at time points 5 (CCA, 0.24±0.14 cm/s; MSA-C, 0.13±0.11 cm/s; (*) p<0.05) and 13 (CCA, -0.60±0.37 cm/s; MSA-C, -0.31±0.17 cm/s; (**) p<0.01). Significant correlations in Spearman's rank correlation coefficient were also found in MSA-C patients between the disease duration and the difference between the maximum and minimum velocities (Vheight) (r=-0.429, (*) p<0.05), the minimum velocity of the CSF (Vmin) (r=0.486, (**) p<0.01) or the length of the minor axis of the pons (r=-0.529, (**) p<0.01). The linear regressions between the disease duration and Vheight or Vmin revealed a significant strong correlation only in the MSA-C patients.

CONCLUSION

The present CSF flow study showed for the first time that Vheight and Vmin revealed good correlations with the disease duration in the MSA-C patients. Furthermore, the velocity of the prepontine CSF flow tended to decrease in the MSA-C patients compared with the CCA patients, suggesting that this particular CSF flow analysis may be a new surrogate marker for differentiating both types of cerebellar ataxia.

"Liberation treatment" for chronic cerebrospinal venous insufficiency in multiple sclerosis: the truth will set you free

BACKGROUND

Chronic cerebrospinal venous insufficiency (CCSVI) has recently been introduced as a chronic state of impaired cerebral or cervical venous drainage that may be causally implicated in multiple sclerosis (MS) pathogenesis. Moreover, percutaneous transluminal angioplasty of extracranial veins termed "Liberation treatment" has been proposed (based on nonrandomized data) as an alternative therapy for MS.

METHODS

A comprehensive literature search was conducted to identify available published, peer-reviewed, clinical studies evaluating (1) the association of CCSVI with MS, (2) the reproducibility of proposed ultrasound criteria for CCSVI detection (3) the safety and efficacy of "Liberation treatment" in open-label and randomized-controlled trial (RCT) settings.

RESULTS

There is substantial heterogeneity between ultrasound case-control studies investigating the association of CCSVI and MS. The majority of independent investigators failed to reproduce the initially reported high prevalence rates of CCSVI in MS. The prevalence of extracranial venous stenoses evaluated by other neuroimaging modalities (contrast or MR venography) is similarly low in MS patients and healthy individuals. One small RCT failed to document any benefit in MS patients with CCSVI receiving "Liberation treatment", while an exacerbation of disease activity was observed. "Liberation treatment" has been complicated by serious adverse events (SAEs) in open-label studies (e.g., stroke, internal jugular vein thrombosis, stent migration, hydrocephalus).

CONCLUSION

CCSVI appears to be a poorly reproducible and clinically irrelevant sonographic construct. "Liberation treatment" has no proven efficacy, may exacerbate underlying disease activity and has been complicated with SAEs. "Liberation treatment" should stop being offered to MS patients even in the settings of RCTs.

MR venography in patients with multiple sclerosis and correlation with clinical and MRI parameters

BACKGROUND AND PURPOSE

Multiple sclerosis (MS) has been associated with chronic cerebrospinal venous insufficiency. We aim to evaluate the correlation between extracranial veins stenosis evaluated with MR venography (MRV) and clinical/MR parameters of MS.

METHODS

In 29 consecutive MS patients we performed a standard brain MRI protocol, completed by the evaluation of extra-cerebral venous system using a phase-contrast and a Volumetric Interpolated Breath Hold Examination (VIBE) sequence before and after gadolinium. The T2-proton density images were used to calculate the lesion volume. The jugular veins were evaluated qualitatively (in terms of presence and severity of stenoses) and quantitatively (degree of stenosis). The phase-contrast images were analyzed to calculate the average and peak velocity in the internal jugular veins.

RESULTS

Postcontrast VIBE successfully showed the jugular veins in all the subjects. T2-lesion-volume was 8.2 [4.6] cm³. A stenosis of the internal jugular veins > of 50% was observed in 10/29(33%) patients. No significant correlation was observed between T2-lesion-volume and degree-of-stenosis (r = .362, P = .302). No different flow parameters were found in the subgroups of patients with and without stenosis (P = .54).

CONCLUSIONS

In MS the presence/severity of jugular vein stenosis identified with 3T-MRV is not related to MR-visible tissue damage. Moreover no abnormal flow parameters were found in stenosed veins.

Is there any relation between chronic cerebrospinal venous insufficiency and multiple sclerosis? - a critical review

Summary Though the etiology of multiple sclerosis remains unknown, the widely accepted explanation is that it has an autoimmune inflammatory background. In 2006 Paolo Zamboni renewed the somewhat forgotten vascular theory of the pathogenesis of multiple sclerosis, proposing the new entity of 'chronic cerebrospinal venous insufficiency'. As a result of this hypothesis, Zamboni suggested an endovascular treatment for multiple sclerosis involving venoplasty of the internal jugular vein and the azygos vein. Unfortunately, several teams have tried to replicate Zamboni's results without success. In this review, we present a chronological description of the results of the studies conducted by Zamboni and the later attempts to replicate his work. The main conclusion is that, taking into account results that are currently available, we should remain cautious and routine use of this treatment in patients should not be advisable.

MR venography in children and adolescents with multiple sclerosis does not show increased prevalence of extracranial veins anomalies

BACKGROUND

Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system that affects mainly young adults, but can occur also in children and adolescents. The pathogenesis of MS is still not fully understood and chronic cerebrospinal venous insufficiency (CCSVI) was suggested to be implicated in MS. Although there is no strong evidence to support this hypothesis, a considerable number of MS patients, including adolescents, have undergone endovascular treatment procedures. The aim of this study was the evaluate the prevalence of extracranial venous system anomalies in children and adolescents with multiple sclerosis in comparison to age-matched controls.

MATERIAL AND METHODS

Twenty-one children with clinically definite diagnosis of MS (mean age 13.8 years), and 19 age-matched controls (mean age 12.5 years) were investigated using 1.5 T scanner with coronal 3D contrast-enhanced coronal venography. The diameters of internal jugular veins (IJV) at both sides of the neck were estimated separately, from the level C1 to Th1.

RESULTS

Anomalies of the extracranial venous system were found in 10 MS patients (47.6%) and 13 controls (68.4%). Normal anatomy of extracranial veins was recognized in 11 MS patients (53%) and 6 controls (31%). Comparison of the measurement results for MS patients and the control group revealed that there are no significant statistical differences in cross-section areas for a given level.

CONCLUSIONS

We found no evidence to suggest that MS children and adolescents have more extracranial veins anomalies than healthy patients. Considering the risk of such treatment, endovascular interventions should be discourage.

Phlebographic study does not show differences between patients with MS and control subjects

BACKGROUND AND PURPOSE

Hypothetical correlation between chronic cerebrospinal venous insufficiency and MS has gained the attention of patients and the scientific community. Studies performed by echo-color Doppler ultrasonography have shown different results, and it is necessary to use more objective diagnostic techniques. The aim of our study was to evaluate the presence of stenoses affecting azygos veins and internal jugular veins by use of venography in patients with MS.

MATERIALS AND METHODS

We recruited 2 groups of subjects who underwent venography: the study group included 29 patients with MS and the control group included 15 healthy volunteers. The ileo-lumbar plexus, the azygos, and the internal jugular veins were selectively catheterized. We considered any cross-sectional area reduction of the venous lumen >50% to be a significant stenosis. Furthermore, blood pressure was measured in the studied vessels at the stenotic internal jugular veins.

RESULTS

Selective venography showed at least 1 significant venous stenosis in 84% of subjects examined, without significant difference between the study group and the control group. Positive venography chronic cerebrospinal venous insufficiency patterns were found in 50% of all subjects examined, without any significant difference between the 2 groups. The multivariate logistic regression analysis failed to assess any significant association between the presence of a positive venography and MS condition. The difference between the median blood pressure of stenotic and nonstenotic internal jugular veins was not statistically significant (P = .46).

CONCLUSIONS

Our data exclude any direct correlation between chronic cerebrospinal venous insufficiency and MS because venous abnormalities were equally present in both groups.

Prevalence of extracranial venous narrowing on catheter venography in people with multiple sclerosis, their siblings, and unrelated healthy controls: a blinded, case-control study

BACKGROUND

Chronic cerebrospinal venous insufficiency has been proposed as a unique combination of extracranial venous blockages and haemodynamic flow abnormalities that occurs only in patients with multiple sclerosis and not in healthy people. Initial reports indicated that all patients with multiple sclerosis had chronic cerebrospinal venous insufficiency. We aimed to establish the prevalence of venous narrowing in people with multiple sclerosis, unaffected full siblings, and unrelated healthy volunteers.

METHODS

We did an assessor-blinded, case-control, multicentre study of people with multiple sclerosis, unaffected siblings, and unrelated healthy volunteers. We enrolled the study participants between January, 2011 and March, 2012, and they comprised 177 adults: 79 with multiple sclerosis, 55 siblings, and 43 unrelated controls, from three centres in Canada. We assessed narrowing of the internal jugular and azygous veins with catheter venography and ultrasound criteria for chronic cerebrospinal venous insufficiency proposed by Zamboni and colleagues. Catheter venography data were available for 149 participants and ultrasound data for 171 participants.

FINDINGS

Catheter venography criteria for chronic cerebrospinal venous insufficiency were positive for one of 65 (2%) people with multiple sclerosis, one of 46 (2%) siblings, and one of 32 (3%) unrelated controls (p=1·0 for all comparisons). Greater than 50% narrowing of any major vein was present in 48 of 65 (74%) people with multiple sclerosis, 31 of 47 (66%) siblings (p=0·41 for comparison with patients with multiple sclerosis), and 26 of 37 (70%) unrelated controls (p=0·82). The ultrasound criteria for chronic cerebrospinal venous insufficiency were fulfilled in 35 of 79 (44%) participants with multiple sclerosis, 17 of 54 (31%) siblings (p=0·15 for comparison with patients with multiple sclerosis) and 17 of 38 (45%) unrelated controls (p=0·98). The sensitivity of the ultrasound criteria for detection of greater than 50% narrowing on catheter venography was 0·406 (95% CI 0·311-0·508), and specificity was 0·643 (0·480-0·780).

INTERPRETATION

This study shows that chronic cerebrospinal venous insufficiency occurs rarely in both patients with multiple sclerosis and in healthy people. Extracranial venous narrowing of greater than 50% is a frequent finding in patients with multiple sclerosis, unaffected siblings, and unrelated controls. The ultrasound criteria are neither sensitive nor specific for narrowing on catheter venography. The significance of venous narrowing to multiple sclerosis symptomatology remains unknown.

FUNDING

MS Society of Canada, Saskatoon City Hospital Foundation, Lotte and John Hecht Memorial Foundation, Vancouver Coastal Health Foundation, and the Wolridge Foundation.

Potential involvement of the extracranial venous system in central nervous system disorders and aging

BACKGROUND

The role of the extracranial venous system in the pathology of central nervous system (CNS) disorders and aging is largely unknown. It is acknowledged that the development of the venous system is subject to many variations and that these variations do not necessarily represent pathological findings. The idea has been changing with regards to the extracranial venous system.

DISCUSSION

A range of extracranial venous abnormalities have recently been reported, which could be classified as structural/morphological, hemodynamic/functional and those determined only by the composite criteria and use of multimodal imaging. The presence of these abnormalities usually disrupts normal blood flow and is associated with the development of prominent collateral circulation. The etiology of these abnormalities may be related to embryologic developmental arrest, aging or other comorbidities. Several CNS disorders have been linked to the presence and severity of jugular venous reflux. Another composite criteria-based vascular condition named chronic cerebrospinal venous insufficiency (CCSVI) was recently introduced. CCSVI is characterized by abnormalities of the main extracranial cerebrospinal venous outflow routes that may interfere with normal venous outflow.

SUMMARY

Additional research is needed to better define the role of the extracranial venous system in relation to CNS disorders and aging. The use of endovascular treatment for the correction of these extracranial venous abnormalities should be discouraged, until potential benefit is demonstrated in properly-designed, blinded, randomized and controlled clinical trials.

No evidence for impairment of venous hemodynamics in children or young adults with pediatric-onset multiple sclerosis

BACKGROUND AND PURPOSE

Chronic cerebrospinal venous insufficiency is a postulated etiologic factor for multiple sclerosis, but the higher frequency with longer disease duration and progressive disability suggests that chronic cerebrospinal venous insufficiency is secondary to chronic disease. We evaluated the presence of chronic cerebrospinal venous insufficiency in pediatric-onset MS.

MATERIALS AND METHODS

Twenty-six pediatric patients with MS (18 years of age or younger), 26 age-matched healthy controls, and 13 young adults with pediatric-onset MS underwent sonography of the internal jugular, vertebral, and deep cerebral veins. Five venous hemodynamic criteria were assessed, with 2 criteria required for chronic cerebrospinal venous insufficiency. MR imaging studies, performed in the pediatric patients with MS and healthy control groups, included intracranial 2D time-of-flight MR venography and velocity-sensitive phase-contrast sequences. Contrast-enhanced brain MR images were obtained in pediatric patients with MS to further evaluate venous patency. We used paired t tests, Wilcoxon matched pairs, McNemar tests, and exact conditional logistic regression to estimate the association of chronic cerebrospinal venous insufficiency with MS.

RESULTS

Fifty participants (73.5%) had normal ultrasound findings, 15 (23.1%) met 1 venous hemodynamic criterion, and 2 pediatric patients with MS and 1 young adult with pediatric-onset MS met chronic cerebrospinal venous insufficiency criteria. Chronic cerebrospinal venous insufficiency was not associated with MS (odds ratio, 2.41; 95% CI, 0.19-infinity). Demographic and disease characteristics did not differ between the patients with MS meeting chronic cerebrospinal venous insufficiency criteria (n = 3) and those who did not (n = 36; all, P > .05). The mean (SD) MR imaging measures of intracerebral flow did not differ between the 2 pediatric patients with MS meeting chronic cerebrospinal venous insufficiency criteria (0.85 ± 0.11) and healthy controls (0.87 ± 0.16, P = .50); no child demonstrated venous obstruction.

CONCLUSIONS

Chronic cerebrospinal venous insufficiency is rarely observed in children or young adults with pediatric-onset MS. Venous anatomy and flow rates indicate that venous outflow is intact in pediatric patients with MS. Our findings argue against chronic cerebrospinal venous insufficiency as a component of MS etiology.

Blood pressure normalization post-jugular venous balloon angioplasty

Objective

This study is the first in a series investigating the relationship between autonomic nervous system dysfunction and chronic cerebrospinal venous insufficiency in multiple sclerosis patients. We screened patients for the combined presence of the narrowing of the internal jugular veins and symptoms of autonomic nervous system dysfunction (fatigue, cognitive dysfunction, sleeping disorders, headache, thermal intolerance, bowel/bladder dysfunction) and determined systolic and diastolic blood pressure responses to balloon angioplasty.

Methods

The criteria for eligibility for balloon angioplasty intervention included ≥50% narrowing in one or both internal jugular veins, as determined by the magnetic resonance venography, and ≥3 clinical symptoms of autonomic nervous system dysfunction. Blood pressure was measured at baseline and post-balloon angioplasty.

Results

Among patients who were screened, 91% were identified as having internal jugular veins narrowing (with obstructing lesions) combined with the presence of three or more symptoms of autonomic nervous system dysfunction. Balloon angioplasty reduced the average systolic and diastolic blood pressure. However, blood pressure categorization showed a biphasic response to balloon angioplasty. The procedure increased blood pressure in multiple sclerosis patients who presented with baseline blood pressure within lower limits of normal ranges (systolic ≤105 mmHg, diastolic ≤70 mmHg) but decreased blood pressure in patients with baseline blood pressure above normal ranges (systolic ≥130 mmHg, diastolic ≥ 80 mmHg). In addition, gender differences in baseline blood pressure subcategories were observed.

Discussion

The coexistence of internal jugular veins narrowing and symptoms of autonomic nervous system dysfunction suggests that the two phenomena may be related. Balloon angioplasty corrects blood pressure deviation in multiple sclerosis patients undergoing internal jugular vein dilation. Further studies should investigate the association between blood pressure deviation and internal jugular veins narrowing, and whether blood pressure normalization affects Patient's clinical outcomes.

Multimodal noninvasive and invasive imaging of extracranial venous abnormalities indicative of CCSVI: results of the PREMiSe pilot study

Background

There is no established noninvasive or invasive diagnostic imaging modality at present that can serve as a ‘gold standard’ or “benchmark” for the detection of the venous anomalies, indicative of chronic cerebrospinal venous insufficiency (CCSVI). We investigated the sensitivity and specificity of 2 invasive vs. 2 noninvasive imaging techniques for the detection of extracranial venous anomalies in the internal jugular veins (IJVs) and azygos vein/vertebral veins (VVs) in patients with multiple sclerosis (MS).

Methods

The data for this multimodal imaging comparison pilot study was collected in phase 2 of the “Prospective Randomized Endovascular therapy in Multiple Sclerosis” (PREMiSe) study using standardized imaging techniques. Thirty MS subjects were screened initially with Doppler sonography (DS), out of which 10 did not fulfill noninvasive screening procedure requirements on DS that consisted of ≥2 venous hemodynamic extracranial criteria. Accordingly, 20 MS patients with relapsing MS were enrolled into the multimodal diagnostic imaging study. For magnetic resonance venography (MRV), IJVs abnormal findings were considered absent or pinpoint flow, whereas abnormal VVs flow was classified as absent. Abnormalities of the VVs were determined only using non-invasive testing. Catheter venography (CV) was considered abnormal when ≥50% lumen restriction was detected, while intravascular ultrasound (IVUS) was considered abnormal when ≥50% restriction of the lumen or intra-luminal defects or reduced pulsatility was found. Non-invasive and invasive imaging modality comparisons between left, right and total IJVs and between the VVs and azygos vein were performed. Because there is no reliable way of non-invasively assessing the azygos vein, the VVs abnormalities detected by the non-invasive testing were compared to the azygos abnormalities detected by the invasive testing. All image modalities were analyzed in a blinded manner by more than one viewer, upon which consensus was reached. The sensitivity and specificity were calculated using contingency tables denoting the presence or absence of vein-specific abnormality findings between all imaging modalities used individually as the benchmark.

Results

The sensitivity of CV + IVUS was 68.4% for the right and 90% for the left IJV and 85.7% for the azygos vein/VVs, compared to venous anomalies detected on DS. Compared to the venous anomalies detected on MRV, the sensitivity of CV + IVUS was 71.4% in right and 100% in left IJVs and 100% in the azygos vein/VVs; however, the specificity was 38.5%, 38.9% and 11.8%, respectively. The sensitivity between the two invasive imaging techniques, used as benchmarks, ranged from 72.7% for the right IJV to 90% for the azygos vein but the IVUS showed a higher rate of venous anomalies than the CV. There was excellent correspondence between identifying collateral veins on MRV and CV.

Conclusions

Noninvasive DS screening for the detection of venous anomalies indicative of CCSVI may be a reliable approach for identifying patients eligible for further multimodal invasive imaging testing of the IJVs. However, the noninvasive screening methods were inadequate to depict the total amount of azygos vein/VVs anomalies identified with invasive testing. This pilot study, with limited sample size, shows that both a non-invasive and invasive multimodal imaging diagnostic approach should be recommended to depict a range of extracranial venous anomalies indicative of CCSVI. However, lack of invasive testing on the study subjects whose results were negative on the DS screening and of healthy controls, limits further generalizibility of our findings. In addition, the findings from the 2 invasive techniques confirmed the existence of severe extracranial venous anomalies that significantly impaired normal blood outflow from the brain in this group of MS patients.

Intracranial pulsatility is associated with regional brain volume in elderly individuals

Excessive intracranial pulsatility is thought to damage the cerebral microcirculation, causing cognitive decline in elderly individuals. We investigated relationships between brain structure and measures related to intracranial pulsatility among healthy elderly. Thirty-seven stroke-free, non-demented individuals (62-82 years of age) were included. We assessed brain structure, invasively measured cerebrospinal fluid (CSF) pulse pressure, and magnetic resonance-quantified arterial and CSF flow pulsatility, as well as arterial pulse pressure. Using both multivariate partial least squares and ordinary regression analyses, we identified a significant pattern of negative relationships between the volume of several brain regions and measures of intracranial pulsatility. The strongest relationships concerned the temporal lobe cortex and hippocampus. These findings were also coherent with observations of positive relationships between intracranial pulsatility and ventricular volume. In conclusion, elderly subjects with high intracranial pulsatility display smaller brain volume and larger ventricles, supporting the notion that excessive cerebral arterial pulsatility harms the brain. This calls for research investigating altered intracranial cardiac-related pulsatile stress as a potential risk factor that may cause or worsen the prognosis in subjects developing cognitive impairment and dementia.

Concomitant analysis of arterial, venous, and CSF flows using phase-contrast MRI: a quantitative comparison between MS patients and healthy controls

Venous dysfunction has recently been hypothesized to contribute to the pathophysiology of multiple sclerosis (MS). 2D phase-contrast (PC) magnetic resonance imaging (MRI) is a non-invasive and innocuous technique enabling reliable quantification of cerebrospinal fluid (CSF) and blood flows in the same imaging session. We compared PC-MRI measurements of CSF, arterial and venous flows in MS patients to those from a normative cohort of healthy controls (HC). Nineteen MS patients underwent a standardized MR protocol for cerebral examination on a 3T system including Fast cine PC-MRI sequences with peripheral gating in four acquisition planes. Quantitative data were processed using a homemade software to extract CSF and blood flow regions of interest, animate flows, and calculate cervical and intracranial vascular flow curves during the cardiac cycle (CC). Results were compared with values obtained in 21 HC using multivariate analysis. Venous flow patterns were comparable in both groups without signs of reflux. Arterial flows (P=0.02) and cervical CSF dynamic oscillations (P=0.01) were decreased in MS patients. No significant differences in venous cerebral and cervical outflows were observed between groups, thereby contradicting the recently proposed theory of venous insufficiency. Unexpected decrease in arterial perfusion in MS patients warrants further correlation to volumetric measurements of the brain.

Evidence against the involvement of chronic cerebrospinal venous abnormalities in multiple sclerosis. A case-control study

Objective

Multiple sclerosis (MS) is a chronic neurodegenerative disease of the CNS. Recently a controversial vascular hypothesis for MS, termed chronic cerebrospinal venous insufficiency (CCSVI), has been advanced. The objective of this study was to evaluate the relative prevalence of the venous abnormalities that define CCSVI.

Methods

A case-control study was conducted in which 100 MS patients aged between 18–65 y meeting the revised McDonald criteria were randomly selected and stratified into one of four MS subtypes: relapsing/remitting, secondary progressive, primary progressive and benign. Control subjects (16–70 y) with no known history of MS or other neurological condition were matched with the MS cases. All cases and controls underwent ultrasound imaging of the veins of the neck plus the deep cerebral veins, and magnetic resonance imaging of the neck veins and brain. These procedures were performed on each participant on the same day.

Results

On ultrasound we found no evidence of reflux, stenosis or blockage in the internal jugular veins (IJV) or vertebral veins (VV) in any study participant. Similarly, there was no evidence of either reflux or cessation of flow in the deep cerebral veins in any subject. Flow was detected in the IJV and VV in all study participants. Amongst 199 participants there was one MS subject who fulfilled the minimum two ultrasound criteria for CCSVI. Using MRI we found no significant differences in either the intra- or extra-cranial venous flow velocity or venous architecture between cases and controls.

Conclusion

This case-control study provides compelling evidence against the involvement of CCSVI in multiple sclerosis.

Feasibility and safety of endovascular treatment for chronic cerebrospinal venous insufficiency in patients with multiple sclerosis

OBJECTIVE

Chronic cerebrospinal venous insufficiency (CCSVI) is a recently discovered syndrome mainly due to stenoses of internal jugular (IJV) and/or azygos (AZ) veins. The present study retrospectively evaluates the feasibility and safety of endovascular treatment for CCSVI in a cohort of patients with multiple sclerosis (MS).

METHODS

From September 2010 to October 2012, 1202 consecutive patients were admitted to undergo phlebograpy ± endovascular treatment for CCSVI. All the patients had previously been found positive at color Doppler sonography (CDS) for at least two Zamboni criteria for CCSVI and had a neurologist-confirmed diagnosis of MS. Only symptomatic MS were considered for treatment. Percutaneous transluminal angioplasty was carried out as an outpatient procedure at two different institutes. Primary procedures, regarded as the first balloon angioplasty ever performed for CCSVI, and secondary (reintervention) procedures, regarded as interventions performed after venous disease recurrence, were carried out in 86.5% (1037 of 1199) and 13.5% (162 of 1199) of patients, respectively. Procedural success and complications within 30 days were recorded.

RESULTS

Phlebography followed by endovascular recanalization was carried out in 1999 patients consisting of 1219 interventions. Balloon angioplasty alone was performed in 1205 out of 1219 (98.9%) procedures, whereas additional stent placement was required in the remaining 14 procedures (1.1%) following unsuccessful attempts at AZ dilatation. No stents were ever implanted in the IJV. The feasibility rate was as high as 99.2% (1209 interventions). Major complications included one (0.1%) AZ rupture occurring during balloon dilatation and requiring blood transfusion, one (0.1%) severe bleeding in the groin requiring open surgery, two (0.2%) surgical openings of the common femoral vein to remove balloon fragments, and three (0.2%) left IJV thromboses. The overall major and minor complication rates at 30 days were 0.6% and 2.5%, respectively.

CONCLUSIONS

Endovascular treatment for CCSVI appears feasible and safe. However, a proper learning curve can dramatically lower the rate of adverse events. In our experience, the vast majority of complications occurred in the first 400 cases performed.

Cognitive impairment and "invisible symptoms" are not associated with CCSVI in MS

BACKGROUND

We investigated the association between chronic cerebrospinal venous insufficiency (CCSVI) and cognitive impairment (CI) in multiple sclerosis (MS). Moreover, we evaluated the association between CCSVI and other frequent self-reported MS symptoms.

METHODS

We looked at the presence of CI in incident MS patients with CCVSI in a population-based cohort of Catania, Italy. All subjects were group-matched by age, sex, disease duration and EDSS score with MS patients without CCSVI, serving as controls. CI was assessed with the Brief Repeatable Battery (BRB) and the Stroop Test (ST) and it was defined by the presence of at least three impaired tests. Fatigue and depressive symptoms were assessed with Fatigue Severity Scale (FSS) and Hamilton Depressive Rating Scale (HDRS), respectively. Bladder and sexual symptoms were assessed with the respective items of the Italian version of Guy's Neurological Disability Scale (GNDS). Quality of life was evaluated with Multiple Sclerosis Quality of Life-54 Instrument (MSQOL-54).

RESULTS

Out of 61 MS patients enrolled in the study, 27 were CCSVI positive and 34 were CCSVI negative. Of them, 43 were women (70.5%); the mean age was 43.9 ± 11.8 years; the mean disease duration was 159.7 ± 113.7 months; mean EDSS was 3.0 ± 2.6. Of them, 36 (59.0%) were classified relapsing-remitting (RR), 12 (19.7%) secondary progressive (SP), seven (11.5%) primary progressive (PP) and six (9.3%) Clinically Isolated Syndrome (CIS). Overall, CI was detected in 29/61 (47.5%) MS patients; particularly 13/27 (48.1%) in the CCSVI positive group and 16/34 (47.0%) in the CCSVI negative group. Presence of CCSVI was not significantly associated with the presence of CI (OR 1.04; 95% CI 0.37-2.87; p-value = 0.9). Not significant differences were found between the two groups regarding the other MS symptoms investigated.

CONCLUSIONS

Our findings suggest a lack of association between CCSVI and CI in MS patients. Fatigue, depressive, bladder/sexual symptoms and self-reported quality of life are not associated with CCSVI.

Small internal jugular veins with restricted outflow are associated with severe multiple sclerosis: a sonographer-blinded, case-control ultrasound study

BACKGROUND

Recent evidence has indicated an association between chronic cerebrospinal venous insufficiency (CCSVI) and multiple sclerosis. Small internal jugular veins (IJVs) (with a cross-sectional area of less than 0.4 cm²) have been previously described as difficult to catheterize, and their presence may potentially affect cerebrospinal venous drainage. In this blinded extracranial color-Doppler study we had two principal aims: first, to assess prevalence of CCSVI among Serbian MS patients compared to healthy controls; and second, to assess prevalence of small IJVs (with a CSA ≤ 0.4 cm²) among MS patients and controls.

METHODS

The sixty seven unrelated patients with clinical isolated syndrome (CIS), relapsing-remitting (RR), secondary progressive (SP) and primary progressive (PP) multiple sclerosis and 21 healthy controls were examined by high-resolution color-Doppler.

RESULTS

The ultrasonographic criteria of CCSVI (according to Zamboni) were positive in 11.9% of the patients and in none of the control subjects. The CCSVI-positive patients had significantly longer disease durations and were significantly more disabled (measured by their Expanded Disability Status Scale (EDSS) and Multiple Sclerosis Severity Score (MSSS) scores), but after adjustment for gender and disease duration, CCSVI was not an independent risk factor for multiple sclerosis severity. The small IJVs were found in 28.4% of the patients and 28.6% of the controls. The patients with small IJVs were associated with decreased venous outflow from the brain and presented with longer disease durations and significantly higher EDSS and MSSS scores compared to patients without small IJVs. A multivariate logistic regression analysis adjusted for gender and disease duration showed that small IJV is an independent factor associated with multiple sclerosis severity (EDSS ≥6) (adjusted OR = 8.9, 95% CI: 1.8-45.6, p = 0.007). Among patients with small IJVs the 36.84% were also CCSVI positive.

CONCLUSIONS

Both, CCSVI and small IJVs seem to influence or follow MS severity, but only small IJVs turned out to be an independent factor in this study. Thus, small IJVs with restricted outflow, which might be aspects of CCSVI different from the criteria originally described by Zamboni, emerge as a cofactor in the multifactorial pathophysiology of multiple sclerosis.

Chronic cerebrospinal venous insufficiency: masked multimodal imaging assessment

BACKGROUND

Chronic cerebrospinal venous insufficiency (CCSVI) was implicated in the pathophysiology of multiple sclerosis (MS).

OBJECTIVE

We evaluated neurosonography (NS), magnetic resonance venography (MRV), and transluminal venography (TLV) in subsets of MS patients drawn from a single-center, prospective, case-control study of 206 MS and 70 non-MS volunteers.

METHODS

As previously reported, findings on high-resolution B-mode NS imaging with color and spectral Doppler of the extracranial and intracranial venous drainage consistent with CCSVI were similar among MS and non-MS volunteers (3.88% vs 7.14%; p = 0.266). Ninety-nine MS participants consented to intravascular contrast-enhanced 3D MRV to assess their major systemic and intracranial venous circulation, and 40 advanced to TLV that included pressure measurements of the superior vena cava, internal jugular, brachiocephalic, and azygous veins.

RESULTS

NS findings and MRV patterns were discrepant for 26/98 evaluable subjects, including four with abnormal findings on NS that had normal venous anatomy by MRV. In no instance were TLV pressure gradients indicative of clinically significant functional stenosis encountered. The three imaging approaches provided generally consistent data with discrepancies referable to inherent technique properties.

CONCLUSIONS

Our findings lend no support for altered venous outflow dynamics as common among MS patients, nor do they likely contribute to the disease process.