No association of abnormal cranial venous drainage with multiple sclerosis: a magnetic resonance venography and flow-quantification study

Association between chronic cerebrospinal venous insufficiency and multiple sclerosis: a systematic review and meta-analysis

OBJECTIVES

Numerous studies have indicated that chronic cerebrospinal venous insufficiency is a potential factor in causing multiple sclerosis in recent years, but this conclusion remains unconfirmed. This meta-analysis examined the correlation between multiple sclerosis and chronic cerebrospinal venous insufficiency.

METHODS

We searched Embase and Medline (Ovid) for publications published from 1 January 2006 to 1 May 2022. The meta-analysis was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

Eligible studies (n=20) included 3069 participants from seven countries. Pooled analysis indicated that chronic cerebrospinal venous insufficiency was more frequent in patients with multiple sclerosis than in healthy controls (OR 3.36; 95% CI 1.92 to 5.85; p<0.001) with remarkable heterogeneity among studies (I2=79%). Results were more strongly correlated in subsequent sensitivity analyses, but heterogeneity was also more substantial. We removed studies that initially proposed a chronic cerebrospinal venous insufficiency team as well as studies by authors involved in or advocating endovascular therapies.

CONCLUSIONS

Chronic cerebrospinal venous insufficiency is significantly associated with multiple sclerosis and it is more prevalent in patients with multiple sclerosis than in healthy individuals, but considerable heterogeneity of results is still observed.

[Changes in venous circulation in patients with multiple sclerosis]

Multiple sclerosis (MS) is a common neurological disease, especially among people of young working age, and the number of MS cases registered in the world and in the Russian Federation tends to increase. The pathogenesis of MS is based on the theory of damage to its own myelin sheath as a result of activation of autoreactive T cells, which also leads to damage to both oligodendrocytes and axons. In addition, the role of vascular factor in the pathogenesis of MS is discussed in the literature periodically and several areas of research of vascular dysfunction in patients are identified. This article provides a retrospective analysis of the available literature dating from the 19th century to the present time in order to find the relationship between MS and changes in venous circulation.

Content and quality analysis of videos about multiple sclerosis on social media: The case of YouTube

BACKGROUND

YouTube (YT) has grown into the largest online video platform across the world. Known to have more than two billion users of all ages, YT also serves as an important educational tool and information source for patients and their families. YT videos have the potential to influence patients' understanding of their diagnoses and treatment decision-making.

METHODS

Videos were identified using the keywords "multiple sclerosis," "multiple sclerosis treatment," "relapsing remitting MS," and "central demyelinating disorder" in the YT search bar. For each search term, the top 30 videos were reviewed. The videos were analyzed by two independent raters using the DISCERN and Global Quality Scale (GQS) scoring systems. Qualitative and quantitative data were recorded for each video.

RESULTS

A total of 99 videos were analyzed. The mean DISCERN score was 43.44 out of 75 possible points, and the mean Global Quality Scale (GQS) score was 2.77 out of 5 possible points. Of all the videos, 14.1, 29.3, 15.2, and 29.3% were categorized as very poor, poor, moderate, good, and excellent, respectively. Videos that included qualitative features such as clear information; information related to symptomatology, etiology, diagnosis, treatment, treatment response, and epidemiology; and diagrams and radiological images had significantly higher scale scores. Audience engagement parameters were significantly higher for videos containing animation, treatment response, and radiological images.

CONCLUSION

We maintain that sufficient, reliable, and useful content is not provided for those seeking information on YT about MS. Everyone seeking information about MS should always verify information provided in YT videos using more reliable sources of information. Video producers should optimize their videos to contain high-quality and reliable data and to attract larger audiences.

Brain oxygen extraction fraction mapping in patients with multiple sclerosis

We aimed to demonstrate the feasibility of whole brain oxygen extraction fraction (OEF) mapping for measuring lesion specific and regional OEF abnormalities in multiple sclerosis (MS) patients. In 22 MS patients and 11 healthy controls (HC), OEF and neural tissue susceptibility (χn) maps were computed from MRI multi-echo gradient echo data. In MS patients, 80 chronic active lesions with hyperintense rim on quantitative susceptibility mapping were identified, and the mean OEF and χn within the rim and core were compared using linear mixed-effect model analysis. The rim showed higher OEF and χn than the core: relative to their adjacent normal appearing white matter, OEF contrast = -6.6 ± 7.0% vs. -9.8 ± 7.8% (p < 0.001) and χn contrast = 33.9 ± 20.3 ppb vs. 25.7 ± 20.5 ppb (p = 0.017). Between MS and HC, OEF and χn were compared using a linear regression model in subject-based regions of interest. In the whole brain, compared to HC, MS had lower OEF, 30.4 ± 3.3% vs. 21.4 ± 4.4% (p < 0.001), and higher χn, -23.7 ± 7.0 ppb vs. -11.3 ± 7.7 ppb (p = 0.018). Our feasibility study suggests that OEF may serve as a useful quantitative marker of tissue oxygen utilization in MS.

Pathogenesis and Management in Cerebrovenous Outflow Disorders

In keeping with its status as one of the major causes of disability and mortality worldwide, brain damage induced by cerebral arterial disease has been the subject of several decades of scientific investigation, which has resulted in a vastly improved understanding of its pathogenesis. Brain injury mediated by venous etiologies, however, such as cerebral, jugular, and vertebral venous outflow disturbance, have been largely ignored by clinicians. Unfortunately, this inattention is not proportional to the severity of cerebral venous diseases, as the impact they exact on the quality of life of affected patients may be no less than that of arterial diseases. This is evident in disease sequelae such as cerebral venous thrombosis (CVT)-mediated visual impairment, epilepsy, and intracranial hypertension; and the long-term unbearable head noise, tinnitus, headache, dizziness, sleeping disorder, and even severe intracranial hypertension induced by non-thrombotic cerebral venous sinus (CVS) stenosis and/or internal jugular venous (IJV) stenosis. In addition, the vertebral venous system (VVS), a large volume, valveless vascular network that stretches from the brain to the pelvis, provides a conduit for diffuse transmission of tumors, infections, or emboli, with potentially devastating clinical consequences. Moreover, the lack of specific features and focal neurologic signs seen with arterial etiologies render cerebral venous disease prone to both to misdiagnoses and missed diagnoses. It is therefore imperative that awareness be raised, and that as comprehensive an understanding as possible of these issues be cultivated. In this review, we attempt to facilitate these goals by systematically summarizing recent advances in the diagnosis and treatment of these entities, including CVT, CVS stenosis, and IJV stenosis, with the aim of providing a valid, practical reference for clinicians.

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.

Lower Arterial Cross-Sectional Area of Carotid and Vertebral Arteries and Higher Frequency of Secondary Neck Vessels Are Associated with Multiple Sclerosis

BACKGROUND AND PURPOSE

Arterial and neck vessel system characteristics of patients with multiple sclerosis have not been previously investigated. Therefore, the aim of this study was to examine the frequency of neck vessels and their cross-sectional areas (in square millimeters) between patients with MS and healthy controls.

MATERIALS AND METHODS

In this study, 193 patients with MS and 193 age- and sex-matched healthy controls underwent 2D TOF venography at 3T. The main arterial (carotid and vertebral), venous (internal jugular), and secondary neck vessels were examined at 4 separate cervical levels (C2/3, C4, C5/6, and C7/T1). The ANCOVA adjusted for age, body mass index, smoking status, hypertension, and heart disease was used to compare the differences between patients with MS and healthy controls.

RESULTS

After controlling for all confounding factors, patients with MS had significantly lower cross-sectional areas of the carotid arteries at the C2/3 (P = .03), C5/6 (P = .026), and C7/T1 (P = .005) levels as well as of the vertebral arteries at the C2/3 (P = .02), C4 (P = .012), and C7/T1 (P = .006) levels, compared with healthy controls. A higher frequency of secondary neck vessels was found at all 4 levels in patients with MS: C2/3 (12.9 versus 10, P < .001), C4 (9.1 versus 7.5, P < .001), C5/6 (7.8 versus 6.8, P = .012), and C7/T1 (8.8 versus 6, P < .001). The total cross-sectional areas of secondary neck vessels were also significantly higher at all 4 levels (P < .03). No significant differences in the cross-sectional areas of jugular veins were found between patients with MS and healthy controls.

CONCLUSIONS

Patients with MS showed lower cross-sectional areas of the carotid and vertebral arteries and a higher frequency of secondary neck vessels and their cross-sectional areas compared with healthy controls.

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.

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.

Prevalence of Extracranial Venous Narrowing on Magnetic Resonance Venography Is Similar in People With Multiple Sclerosis, Their Siblings, and Unrelated Healthy Controls: A Blinded, Case-Control Study

PURPOSE

The study sought to assess and compare the prevalence of narrowing of the major extracranial veins in subjects with multiple sclerosis and controls, and to assess the sensitivity and specificity of magnetic resonance venography (MRV) for describing extracranial venous narrowing as it applies to the chronic cerebrospinal venous insufficiency theory, using catheter venography (CV) as the gold standard.

METHODS

The jugular and azygos veins were assessed with time-of-flight MRV in this assessor-blinded, case-control study of subjects with multiple sclerosis, their unaffected siblings, and unrelated controls. The veins were evaluated by diameter and area, and compared with CV. Collateral vessels were also analyzed for maximal diameter, as a potential indicator of compensatory flow.

RESULTS

A high prevalence of extracranial venous narrowing was demonstrated in all study groups, collectively up to 84% by diameter criteria and 90% by area, with no significant difference between the groups when assessed independently (P = .34 and .63, respectively). There was high interobserver variability in the reporting of vessel narrowing (kappa = 0.32), and poor vessel per vessel correlation between narrowing on MRV and CV (kappa = 0.064). Collateral neck veins demonstrated no convincing difference in maximum size or correlation with jugular narrowing.

CONCLUSION

There is a high prevalence of narrowing of the major extracranial veins on MRV in all 3 study groups, with no significant difference between them. These findings do not support the chronic cerebrospinal venous insufficiency theory. Although MRV has shown a high sensitivity for identifying venous narrowing, time-of-flight imaging demonstrates poor interobserver agreement and poor specificity when compared with the gold standard CV.

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.

Cerebral hypoperfusion: a new pathophysiologic concept in multiple sclerosis?

The exact pathogenesis of multiple sclerosis (MS) is incompletely understood. Although auto-immune responses have an important role in the development of hallmark focal demyelinating lesions, the underlying mechanism of axonal degeneration, the other key player in MS pathology and main determinant of long-term disability, remains unclear and corresponds poorly with inflammatory disease activity. Perfusion-weighted imaging studies have demonstrated that there is a widespread cerebral hypoperfusion in patients with MS, which is present from the early beginning to more advanced disease stages. This reduced cerebral blood flow (CBF) does not seems to be secondary to loss of axonal integrity with decreased metabolic demands but appears to be mediated by elevated levels of the potent vasospastic peptide endothelin-1 in the cerebral circulation. Evidence is evolving that cerebral hypoperfusion in MS is associated with chronic hypoxia, focal lesion formation, diffuse axonal degeneration, cognitive dysfunction, and fatigue. Restoring CBF may therefore emerge as a new therapeutic target in MS.

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.

In vivo analysis of physiological 3D blood flow of cerebral veins

OBJECTIVES

To visualize and quantify physiological blood flow of intracranial veins in vivo using time-resolved, 3D phase-contrast MRI (4D flow MRI), and to test measurement accuracy.

METHODS

Fifteen healthy volunteers underwent repeated ECG-triggered 4D flow MRI (3 Tesla, 32-channel head coil). Intracranial venous blood flow was analysed using dedicated software allowing for blood flow visualization and quantification in analysis planes at the superior sagittal, straight, and transverse sinuses. MRI was evaluated for intra- and inter-observer agreement and scan-rescan reproducibility. Measurements of the transverse sinuses were compared with transcranial two-dimensional duplex ultrasound.

RESULTS

Visualization of 3D blood flow within cerebral sinuses was feasible in 100 % and within at least one deep cerebral vein in 87 % of the volunteers. Blood flow velocity/volume increased along the superior sagittal sinus and was lower in the left compared to the right transverse sinus. Intra- and inter-observer reliability and reproducibility of blood flow velocity (mean difference 0.01/0.02/0.02 m/s) and volume (mean difference 0.0002/-0.0003/0.00003 l/s) were good to excellent. High/low velocities were more pronounced (8 % overestimation/9 % underestimation) in MRI compared to ultrasound.

CONCLUSIONS

Four-dimensional flow MRI reliably visualizes and quantifies three-dimensional cerebral venous blood flow in vivo and is promising for studies in patients with sinus thrombosis and related diseases.

KEY POINTS

• 4D flow MRI can be used to visualize and quantify physiological cerebral venous haemodynamics • Flow quantification within cerebral sinuses reveals high reliability and accuracy of 4D flow MRI • Blood flow volume and velocity increase along the superior sagittal sinus • Limited spatial resolution currently precludes flow quantification in small cerebral veins.

"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.

Internal jugular veins out flow in patients with multiple sclerosis:a catheter venography study

PURPOSE

To investigate an examiner-independent catheter venography protocol that could be used to reliably diagnose venous outflow abnormalities in patients with multiple sclerosis (MS) and chronic cerebrospinal venous insufficiency and to determine whether venous angioplasty is effective in the treatment of these abnormalities.

MATERIALS AND METHODS

A total of 313 patients with MS and 12 patients with end-stage renal disease underwent echo-color Doppler sonography and catheter venography of the internal jugular veins (IJVs) to evaluate contrast medium clearance time. In patients with venous outflow anomalies, balloon angioplasty of the IJVs was performed.

RESULTS

A contrast medium clearance time cutoff value of 4 seconds or less provided the maximal combination of sensitivity and specificity for the right IJV (sensitivity, 73.4%; specificity, 100%) and left IJV (sensitivity, 91.4%; specificity, 100%). IJVs with a clearance time between 4.1 and 6 seconds had moderate delayed flow (MDF), and IJVs with a clearance time longer than 6 seconds had severe delayed flow (SDF); 89% of patients showed MDF/SDF through at least one IJV, 79% showed MDF/SDF through both IJVs, and only 5% showed normal flow in both IJVs. Balloon angioplasty was immediately able to improve flow in at least one IJV in 69% of patients, but venous flow was normalized in both veins in only 37% of patients; SDF persisted after angioplasty in 32% of patients.

CONCLUSIONS

There is a high prevalence of abnormal delayed flow through IJVs in patients with MS. Venous angioplasty was effective in only a minority of patients with SDF.

Prospective randomized trial of venous angioplasty in MS (PREMiSe)

OBJECTIVE

We report the results of the investigation of safety and efficacy of venous angioplasty in patients with multiple sclerosis (MS) with findings of extracranial venous anomalies, considered hallmarks of chronic cerebrospinal venous insufficiency (CCSVI), in a 2-phase study (ClinicalTrials.gov NCT01450072).

METHODS

Phase 1 was an open-label safety study (10 patients); phase 2 was sham-controlled, randomized, and double-blind (10 sham procedure, 9 treated). All study patients fulfilled venous hemodynamic screening criteria indicative of CCSVI. Assessment was at 1, 3, and 6 months postprocedure with MRI, clinical, and hemodynamic outcomes. Primary endpoints were safety at 24 hours and 1 month, venous outflow restoration >75% at 1 month, and effect of angioplasty on new lesion activity and relapse rate over 6 months. Secondary endpoints included changes in disability, brain volume, cognitive tests, and quality of life.

RESULTS

No perioperative complications were noted; however, one patient with history of syncope was diagnosed with episodic bradycardia requiring placement of a pacemaker before discharge. Doppler evidence-based venous hemodynamic insufficiency severity score (VHISS) was reduced >75% compared to baseline in phase 1 (at 1 month) but not phase 2. In phase 2, higher MRI activity (cumulative number of new contrast-enhancing lesions [19 vs 3, p = 0.062] and new T2 lesions [17 vs 3, p = 0.066]) and relapse activity (4 vs 1, p = 0.389) were identified as nonsignificant trends in the treated vs sham arm over 6 months. Using analysis of covariance, significant cumulative new T2 lesions were related to larger VHISS decrease (p = 0.028) and angioplasty (p = 0.01) over the follow-up. No differences in other endpoints were detected.

CONCLUSION

Venous angioplasty is not an effective treatment for MS over the short term and may exacerbate underlying disease activity.

CLASSIFICATION OF EVIDENCE

This is a Class I study demonstrating that clinical and imaging outcomes are no better or worse in patients with MS identified with venous outflow restriction who receive venous angioplasty compared to sham controls who do not receive angioplasty. This study also includes a Class IV phase 1 study of safety in 10 patients receiving the angioplasty procedure.

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.

Sources of information and behavioral patterns in online health forums: observational study

Background

Increasing numbers of patients are raising their voice in online forums. This shift is welcome as an act of patient autonomy, reflected in the term “expert patient”. At the same time, there is considerable concern that patients can be easily misguided by pseudoscientific research and debate. Little is known about the sources of information used in health-related online forums, how users apply this information, and how they behave in such forums.

Objective

The intent of the study was to identify (1) the sources of information used in online health-related forums, and (2) the roles and behavior of active forum visitors in introducing and disseminating this information.

Methods

This observational study used the largest German multiple sclerosis (MS) online forum as a database, analyzing the user debate about the recently proposed and controversial Chronic Cerebrospinal Venous Insufficiency (CCSVI) hypothesis. After extracting all posts and then filtering relevant CCSVI posts between 01 January 2008 and 17 August 2012, we first identified hyperlinks to scientific publications and other information sources used or referenced in the posts. Employing k-means clustering, we then analyzed the users’ preference for sources of information and their general posting habits.

Results

Of 139,912 posts from 11,997 threads, 8628 posts discussed or at least mentioned CCSVI. We detected hyperlinks pointing to CCSVI-related scientific publications in 31 posts. In contrast, 2829 different URLs were posted to the forum, most frequently referring to social media, such as YouTube or Facebook. We identified a total of 6 different roles of hyperlink posters including Social Media Fans, Organization Followers, and Balanced Source Users. Apart from the large and nonspecific residual category of the “average user”, several specific behavior patterns were identified, such as the small but relevant groups of CCSVI-Focused Responders or CCSVI Activators.

Conclusions

The bulk of the observed contributions were not based on scientific results, but on various social media sources. These sources seem to contain mostly opinions and personal experience. A small group of people with distinct behavioral patterns played a core role in fuelling the discussion about CCSVI.

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.

"People power" or "pester power"? YouTube as a forum for the generation of evidence and patient advocacy

OBJECTIVE

Venoplasty has been proposed, alongside the theory of chronic cerebrospinal venous insufficiency (CCSVI), as a treatment for multiple sclerosis (MS). Despite concerns about its efficacy and safety, thousands of patients have undergone the procedure. This paper analyses YouTube videos where patients have shared their treatment experiences.

METHODS

Content analysis on the 100 most viewed videos from over 4000 identified in a search for 'CCSVI', and qualitative thematic analysis on popular 'channels' demonstrating patients' experiences.

RESULTS

Videos adopt an overwhelmingly positive stance towards CCSVI; many were uploaded by patients and present pre- and/or post-treatment experiences. Patients demonstrate rather than merely describe their symptoms, performing tests on themselves before and after treatment to quantify improvement. Videos combine medical terminology and tests with personal experiences of living with MS.

CONCLUSION

Social media technologies provide patients with novel opportunities for advocating for particular treatments; generating alternative forms of 'evidence' built on a hybrid of personal experience and medical knowledge.

PRACTICE IMPLICATIONS

Healthcare practitioners need to engage with new digital forms of content, including online social media. Instead of disregarding sources not considered 'evidence-based', practitioners should enhance their understanding of what 'experiential-evidence' is deemed significant to patients, particularly in contested areas of healthcare.

Reproducibility of cerebrospinal venous blood flow and vessel anatomy with the use of phase contrast-vastly undersampled isotropic projection reconstruction and contrast-enhanced MRA

BACKGROUND AND PURPOSE

The chronic cerebrospinal venous insufficiency hypothesis raises interest in cerebrospinal venous blood flow imaging, which is more complex and less established than in arteries. For accurate assessment of venous flow in chronic cerebrospinal venous insufficiency diagnosis and research, we must account for physiologic changes in flow patterns. This study examines day-to-day flow variability in cerebrospinal veins by use of 4D MR flow and contrast-enhanced MRA under typical, uncontrolled conditions in healthy individuals.

MATERIALS AND METHODS

Ten healthy volunteers were scanned in a test-retest fashion by use of a 4D flow MR imaging technique and contrast-enhanced MRA. Flow parameters obtained from phase contrast-vastly undersampled isotropic projection reconstruction and contrast-enhanced MRA scoring measurements in the head, neck, and chest veins were analyzed for internal consistency and interscan reproducibility.

RESULTS

Internal consistency was satisfied at the torcular herophili, with an input-output difference of 2.2%. Percentages of variations in flow were 20.3%, internal jugular vein; 20.4%, azygos vein; 6.8%, transverse sinus; and 5.1%, common carotid artery. Retrograde flow was found in the lower internal jugular vein (4.8%) and azygos vein (7.2%). Contrast-enhanced MRA interscan κ values for the internal jugular vein (left: 0.474, right: 0.366) and azygos vein (-0.053) showed poor interscan agreement.

CONCLUSIONS

Phase contrast-vastly undersampled isotropic projection reconstruction blood flow measurements are reliable and highly reproducible in intracranial veins and in the common carotid artery but not in veins of the neck (internal jugular vein) and chest (azygos vein) because of normal physiologic variation. Retrograde flow normally may be observed in the lower internal jugular vein and azygos vein. Low interrater agreement in contrast-enhanced MRA scans was observed. These findings have important implications for imaging diagnosis and experimental research of chronic cerebrospinal venous insufficiency.

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.

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.

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.

Prevalence of incidental narrowing of the superior segment of the internal jugular vein in patients without multiple sclerosis

PURPOSE

Internal jugular vein (IJV) narrowing superiorly is likely relatively frequent. IJV narrowing has been proposed as a potential pathophysiologic component for multiple sclerosis (MS). Our purpose was to investigate the prevalence of incidental superior IJV narrowing in patients imaged with neck computed tomography angiography (CTA) for reasons unrelated to IJV pathology or MS.

METHODS

We retrospectively identified 164 consecutive adult patients who had undergone neck CTA in which at least one IJV superior segment was opacified (158 right, 155 left IJVs). At the narrowest point of the upper IJV, each IJV was assessed for dominance, graded (shape and narrowing), measured (diameter and area), and located (axially and craniocaudally). Associations were analyzed using Spearman rank correlations (p < 0.05 significant). Medical records were reviewed for MS.

RESULTS

Among 164 patients, at least one IJV was: absent/pinpoint in 15 % (25/164), occluded/nearly occluded in 26 % (43/164). Shape, narrowing, and the three measurements all correlated with each other (all p < 0.01). Lateral location with respect to C1 transverse foramen correlated with subjectively and objectively smaller IJVs (p < 0.01). The most common craniocaudal location was at the C1 transverse process (79 % (125/158) of right and 81 % (126/155) of left IJVs). No patient had a diagnosis of MS.

CONCLUSIONS

The appearance of the superior IJV is variable, with an occlusive/near-occlusive appearance present in approximately one-quarter of patients without known MS undergoing CTA. Radiologists should be aware of and cautious to report or ascribe clinical significance to this frequent anatomic variant.

The role of noninvasive and invasive diagnostic imaging techniques for detection of extra-cranial venous system anomalies and developmental variants

The extra-cranial venous system is complex and not well studied in comparison to the peripheral venous system. A newly proposed vascular condition, named chronic cerebrospinal venous insufficiency (CCSVI), described initially in patients with multiple sclerosis (MS) has triggered intense interest in better understanding of the role of extra-cranial venous anomalies and developmental variants. So far, there is no established diagnostic imaging modality, non-invasive or invasive, that can serve as the "gold standard" for detection of these venous anomalies. However, consensus guidelines and standardized imaging protocols are emerging. Most likely, a multimodal imaging approach will ultimately be the most comprehensive means for screening, diagnostic and monitoring purposes. Further research is needed to determine the spectrum of extra-cranial venous pathology and to compare the imaging findings with pathological examinations. The ability to define and reliably detect noninvasively these anomalies is an essential step toward establishing their incidence and prevalence. The role for these anomalies in causing significant hemodynamic consequences for the intra-cranial venous drainage in MS patients and other neurologic disorders, and in aging, remains unproven.

Venous hemodynamics in neurological disorders: an analytical review with hydrodynamic analysis

Venous abnormalities contribute to the pathophysiology of several neurological conditions. This paper reviews the literature regarding venous abnormalities in multiple sclerosis (MS), leukoaraiosis, and normal-pressure hydrocephalus (NPH). The review is supplemented with hydrodynamic analysis to assess the effects on cerebrospinal fluid (CSF) dynamics and cerebral blood flow (CBF) of venous hypertension in general, and chronic cerebrospinal venous insufficiency (CCSVI) in particular.CCSVI-like venous anomalies seem unlikely to account for reduced CBF in patients with MS, thus other mechanisms must be at work, which increase the hydraulic resistance of the cerebral vascular bed in MS. Similarly, hydrodynamic changes appear to be responsible for reduced CBF in leukoaraiosis. The hydrodynamic properties of the periventricular veins make these vessels particularly vulnerable to ischemia and plaque formation.Venous hypertension in the dural sinuses can alter intracranial compliance. Consequently, venous hypertension may change the CSF dynamics, affecting the intracranial windkessel mechanism. MS and NPH appear to share some similar characteristics, with both conditions exhibiting increased CSF pulsatility in the aqueduct of Sylvius.CCSVI appears to be a real phenomenon associated with MS, which causes venous hypertension in the dural sinuses. However, the role of CCSVI in the pathophysiology of MS remains unclear.

Assessment of jugular endovascular malformations in chronic cerebrospinal venous insufficiency: colour-Doppler scanning and catheter venography compared with intravascular ultrasound

OBJECTIVES

Chronic cerebrospinal venous insufficiency (CCSVI) is a malformative condition characterized by several anomalies of the azygos and/or internal jugular veins (IJVs). Recommended diagnosis of CCSVI is performed with colour-Doppler (CD) sonography. Though catheter venography (CV) is considered as the gold standard for determining vascular anatomy, its uniplanar point of view does not allow an overall evaluation of endoluminal structures. This limit could be addressed by intravascular ultrasound (IVUS). The aim of this report is to evaluate, in patients with multiple sclerosis (MS), the accuracy of CD sonography and CV versus IVUS in estimating the diameter and the cross-sectional area (CSA) of the IJVs and in detecting jugular endoluminal malformations (JEM).

METHOD

Forty-five MS patients with CCSVI, diagnosed by CD sonography, were submitted to CV during IJVs angioplasty. Twenty-five subjects were also examined with IVUS. The IJVs maximum diameter (MAXD) and CSA were estimated. CD and CV data were compared with IVUS data with the Bland-Altman method.

RESULTS

The mean difference in IJV MAXD recorded by CD and IVUS was -0.5 mm. The mean difference in IJV MAXD recorded by CV and IVUS was 3.36 mm. The mean difference in IJV CSA recorded by CD and IVUS was -11.2 mm(2). JEM recorded by IVUS were detected by CD sonography and CV with 88% and 32% accuracy, respectively.

CONCLUSIONS

CV was significantly inferior to CD sonography and IVUS in detecting JEM. Differences between IVUS and CD sonography in detecting JEM and in quantifying jugular diameters were not significant. The IJV CSA was underestimated by CD sonography compared with IVUS. CD sonography was proven to be important in the anatomical characterization of CCSVI, providing useful information for correct intravascular treatment.

What went wrong? The flawed concept of cerebrospinal venous insufficiency

In 2006, Zamboni reintroduced the concept that chronic impaired venous outflow of the central nervous system is associated with multiple sclerosis (MS), coining the term of chronic cerebrospinal venous insufficiency ('CCSVI'). The diagnosis of 'CCSVI' is based on sonographic criteria, which he found exclusively fulfilled in MS. The concept proposes that chronic venous outflow failure is associated with venous reflux and congestion and leads to iron deposition, thereby inducing neuroinflammation and degeneration. The revival of this concept has generated major interest in media and patient groups, mainly driven by the hope that endovascular treatment of 'CCSVI' could alleviate MS. Many investigators tried to replicate Zamboni's results with duplex sonography, magnetic resonance imaging, and catheter angiography. The data obtained here do generally not support the 'CCSVI' concept. Moreover, there are no methodologically adequate studies to prove or disprove beneficial effects of endovascular treatment in MS. This review not only gives a comprehensive overview of the methodological flaws and pathophysiologic implausibility of the 'CCSVI' concept, but also summarizes the multimodality diagnostic validation studies and open-label trials of endovascular treatment. In our view, there is currently no basis to diagnose or treat 'CCSVI' in the care of MS patients, outside of the setting of scientific research.

Changes of cine cerebrospinal fluid dynamics in patients with multiple sclerosis treated with percutaneous transluminal angioplasty: a case-control study

PURPOSE

To investigate characteristics of cine phase contrast-calculated cerebrospinal fluid (CSF) flow and velocity measures in patients with relapsing-remitting (RR) multiple sclerosis (MS) receiving standard medical treatment who had been diagnosed with chronic cerebrospinal venous insufficiency (CCSVI) and underwent percutaneous transluminal angioplasty (PTA).

MATERIALS AND METHODS

This case-controlled, magnetic resonance (MR) imaging-blinded study included 15 patients with RR MS who presented with significant stenoses (≥50% lumen reduction on catheter venography) in the azygous or internal jugular veins. Eight patients underwent PTA in addition to medical therapy immediately following baseline assessments (case group) and seven had delayed PTA after 6 months of medical therapy alone (control group). CSF flow and velocity measures were quantified over 32 phases of the cardiac cycle by a semiautomated method. Outcomes were compared between groups at baseline and at 6 and 12 months of the study by mixed-effect model analysis.

RESULTS

At baseline, no significant differences in CSF flow or velocity measures were detected between groups. At month 6, significant improvement in flow (P<.001) and velocity (P = .013) outcomes were detected in the immediate versus the delayed group, and persisted to month 12 (P = .001 and P = .021, respectively). Within-group flow comparisons from baseline to follow-up showed a significant increase in the immediate group (P = .033) but a decrease in the delayed group (P = .024). Altered CSF flow and velocity measures were associated with worsening of clinical and MR outcomes in the delayed group.

CONCLUSIONS

PTA in patients with MS with CCSVI increased CSF flow and decreased CSF velocity, which are indicative of improved venous parenchyma drainage.

Cerebral hypoperfusion in multiple sclerosis is reversible and mediated by endothelin-1

Decreased cerebral blood flow (CBF) may contribute to the pathology of multiple sclerosis (MS), but the underlying mechanism is unknown. We investigated whether the potent vasoconstrictor endothelin-1 (ET-1) is involved. We found that, compared with controls, plasma ET-1 levels in patients with MS were significantly elevated in blood drawn from the internal jugular vein and a peripheral vein. The jugular vein/peripheral vein ratio was 1.4 in patients with MS vs. 1.1 in control subjects, suggesting that, in MS, ET-1 is released from the brain to the cerebral circulation. Next, we performed ET-1 immunohistochemistry on postmortem white matter brain samples and found that the likely source of ET-1 release are reactive astrocytes in MS plaques. We then used arterial spin-labeling MRI to noninvasively measure CBF and assess the effect of the administration of the ET-1 antagonist bosentan. CBF was significantly lower in patients with MS than in control subjects and increased to control values after bosentan administration. These data demonstrate that reduced CBF in MS is mediated by ET-1, which is likely released in the cerebral circulation from reactive astrocytes in plaques. Restoring CBF by interfering with the ET-1 system warrants further investigation as a potential new therapeutic target for MS.

CCSVI is associated with multiple sclerosis

OBJECTIVES

To analyze all the arguments against chronic cerebrospinal venous insufficiency (CCSVI) as a medical entity, and its association with multiple sclerosis (MS) and to revise all the findings suggesting a possible connection between these two entities.

METHODS

We revised the methodology and results of all fourteen published studies on prevalence of CCSVI in MS patients. Furthermore, we take into consideration other work dealing with possible causes and explanations of venous, as well as vascular dysfunctions linked with MS.

RESULTS

Studies of prevalence show a great variability in prevalence of CCSVI in MS patients. However, a recent meta-analysis assessed an over 13 times increased prevalence in MS. Global hypoperfusion of the brain, and reduced cerebral spinal fluid dynamics in MS was shown to be related to CCSVI. Post-mortem studies show a higher prevalence of intraluminal defects in the main extracranial vein in MS patients in respect to controls.

DISCUSSION

Taking into account the current epidemiological data, the autoptic findings, and the relationship between CCSVI and both hypoperfusion and cerebrospinal fluid flow, CCSVI can be inserted in the list of multiple factors involved in MS pathogenesis. Our careful data analysis may conclude that great variability in prevalence of CCSVI in MS patients can be a result of different methodologies used in venous ultrasound assessment. Finally, it has been proven that CCSVI share the three main risk factors with MS. On the other hand, smoking is the most important risk factor for endothelial cell damage, vitamin D has a protective role and Epstein-Barr virus passes the blood-brain barrier by invading the endothelial cells, therefore, epidemiologically, linking the imbalance of these three factors to MS through autoimmunity.

Heart disease, overweight, and cigarette smoking are associated with increased prevalence of extra-cranial venous abnormalities

OBJECTIVES

Most of the extra-cranial venous abnormalities have been previously described as truncular venous malformations. In this hypothesis-driven study, we evaluated possible association of risk/protective factors with the presence of truncular and functional venous abnormalities in internal jugular veins (IJVs) in a large cohort of volunteers without known central nervous system (CNS) pathology.

METHODS

The study included 240 controls who underwent physical and Doppler sonography (DS) examinations for the presence of intra- and extra-luminal structural and functional abnormalities of the IJVs, and were assessed with a physical examination and structured environmental questionnaire for demographic characteristics, presence of autoimmune and other concomitant diseases, vascular risk factors, environmental factors, and habits. Logistic regression analysis was used to test which risk/protective factors were associated with the presence and number of extra-cranial venous abnormalities.

RESULTS

Subjects with heart disease (P<0·001), overweight (P = 0·005), and smoking (P = 0·016) had a significantly increased number of intra-luminal structural venous abnormalities. Presence of heart disease increased the risk of a malformed valve 12·9 times (95% CI: 5·4-31·3, P<0·001), while smoking increased it 2·21 times (95% CI: 1-4·9, P = 0·033). Being overweight (P = 0·003), a history of mononucleosis (P = 0·012) and smoking (P = 0·042) increased risk for presence of a flap. No association was found between the investigated risk factors and extra-luminal or functional venous abnormalities. However, use of dietary and herbal supplements had a protective role for the presence of functional venous abnormalities.

CONCLUSIONS

There is a close association between intra-luminal, structural, extra-cranial, venous system pathology and the presence of heart disease, overweight, and smoking.