No association between chronic cerebrospinal venous insufficiency and pediatric-onset multiple sclerosis

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.

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.

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.

Evaluation of hemodynamic properties of cerebral venous drainage in patients with multiple sclerosis: a case-control study

Background

The purpose of this study was to compare patients with multiple sclerosis and healthy control subjects as regards hemodynamics of cerebral venous drainage.

Material/Methods

Between December 2012 and May 2013, 44 consecutive patients with multiple sclerosis and 44 age- and sex-matched healthy subjects underwent the B-mode, color Doppler, and duplex Doppler evaluations of the internal jugular vein (IJV) and vertebral vein. The following four parameters were investigated: IJV stenosis, reversal of postural control of the cerebral venous outflow pathways, absence of detectable blood flow in the IJVs and/or vertebral veins, and reflux in the IJVs and/or vertebral veins in the sitting or supine position.

Results

In the study group, IJV stenosis, postural control reversal of the cerebral venous outflow pathways, and absence of flow in the IJVs and/or vertebral veins were found in 3 (6.8%), 2 (4.5%), and 3 (6.8%) patients, respectively. In the control group, IJV stenosis (P=0.12), postural control reversal of the cerebral venous outflow pathways (P=0.50), and absence of flow (P=0.12) were not detected. Abnormal reflux was found neither in multiple sclerosis patients nor in healthy subjects.

Conclusions

No significant difference in the cerebral venous drainage through the IJV or vertebral vein was found between patients with multiple sclerosis and healthy subjects within any of the investigated ultrasonographic parameters.

Chronic cerebrospinal venous insufficiency and multiple sclerosis: a comprehensive meta-analysis of case-control studies

OBJECTIVES

Chronic cerebrospinal venous insufficiency (CCSVI) has recently been implicated in the pathogenesis of multiple sclerosis (MS). This comprehensive meta-analysis of case-control studies investigates the association of CCSVI with MS.

METHODS

Through Medline, EMBASE and Cochrane database searches, case-control ultrasound studies comparing CCSVI frequency among patients with MS and healthy controls were identified.

RESULTS

We identified 19 eligible studies including 1250 patients with MS and 899 healthy controls. The pooled analysis showed that CCSVI was associated with MS [odds ratio (OR) 8.35; 95% confidence interval (CI) 3.44-20.31; p < 0.001) with considerable heterogeneity across studies (I (2) = 80.1%). This association was substantially attenuated in sensitivity analyses excluding studies that were carried out by the group that originally described CCSVI, included investigators who had also been involved in publications advocating endovascular procedures for CCSVI treatment, or were conducted in Italy. Our most conservative sensitivity analysis combining different exclusion criteria yielded no association of CCSVI with MS (OR 1.35; 95% CI 0.62-2.93; p = 0.453) without any heterogeneity (I (2) = 0%).

CONCLUSION

There is considerable heterogeneity across different case-control studies evaluating the association of CCSVI and MS. The greatest factor contributing to this heterogeneity appears to be the involvement of investigators in other publications supporting endovascular procedures as a novel MS treatment.

"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.

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.

A reliability study of colour-Doppler sonography for the diagnosis of chronic cerebrospinal venous insufficiency shows low inter-rater agreement

OBJECTIVE

Chronic cerebrospinal venous insufficiency (CCSVI) has been extremely variable, associated with multiple sclerosis in colour-Doppler sonographic studies. We aimed to evaluate inter-rater agreement in a colour-Doppler sonography venous examination.

DESIGN

Inter-rater agreement study.

SETTING

First-referral multiple sclerosis centre.

PARTICIPANTS

38 patients with multiple sclerosis and 55 age-matched (±5 years) controls.

INTERVENTION

Sonography was carried out in accordance with Zamboni's five criteria by eight sonographers with different expertise, blinded to the status of cases and controls. Each participant was evaluated by two operators.

PRIMARY AND SECONDARY OUTCOME MEASURES

Inter-rater agreement was measured through the κ statistics and the intraclass correlation coefficient.

RESULTS

The agreement was no higher than chance for criterion 2-reflux in the deep cerebral veins (κ=-0.02) and criterion 4-flow not Doppler detectable in one or both the internal jugular veins (IJVs) or vertebral veins (VVs; -0.09). It was substantially low for criterion 1-reflux in the IJVs and/or VVs (0.29), criterion 3-IJV stenosis or malformations (0.23) and criterion 5-absence of IJV diameter increase when passing from the sitting to the supine position (0.22). The κ value for CCSVI as a whole was 0.20 (95% confidence limit -0.01 to 0.42). Intraclass correlation coefficients for the measure of cross-sectional area ranged from 0.05 to 0.25. Inter-rater agreement was low for CCSVI experts (κ=0.24; -0.11 to 0.59) and non-experts (0.20; -0.33 to 0.73); neurologists (0.21; -0.06 to 0.47) and non-neurologists (0.18; -0.20 to 0.56); cases (0.19; -0.14 to 0.52) and controls (0.21; -0.08 to 0.49). Zamboni-trained neurosonographers ascertained CCSVI more frequently than the non-trained neurosonographers.

CONCLUSIONS

Agreement was unsatisfactory for the diagnosis of CCSVI as a whole, for each of its five criteria and according to the different subgroups. Standardisation of the method is urgently needed prior to its further application in studies of patients with multiple sclerosis or other neurological diseases.

Chronic cerebrospinal venous insufficiency is unlikely to be a direct trigger of multiple sclerosis

BACKGROUND

Chronic cerebrospinal venous insufficiency, a vascular pathology affecting the veins draining the central nervous system can accompany multiple sclerosis and is suspected to be involved in its pathogenesis.

OBJECTIVE

This study was aimed at exploring a potential role for chronic cerebrospinal venous insufficiency in triggering multiple sclerosis. If it were venous abnormalities responsible for neurological pathology, one should expect negative correlation, i.e. more severe vascular lesions in the patients with early onset of multiple sclerosis.

METHODS

Localization and degree of venous blockages in 350 multiple sclerosis patients were assessed using catheter venography. Statistical analysis comprised evaluation of the correlations between severity of venous lesions and patients' age at onset of the disease.

RESULTS

We found weak, yet statistically significant positive correlations between patients' age at onset of multiple sclerosis and accumulated and maximal scores of venous lesions. The patients, also those with duration of multiple sclerosis not longer than 5 years, who had their first attack of the disease at younger age, presented with less severe vascular lesions.

CONCLUSION

Positive correlation suggests that venous lesions are not directly triggering multiple sclerosis. There should be another factor that initiates pathological processes in the central nervous system.

Observational case-control study of the prevalence of chronic cerebrospinal venous insufficiency in multiple sclerosis: results from the CoSMo study

BACKGROUND

Chronic cerebrospinal venous insufficiency (CCSVI) has been proposed as a possible cause of multiple sclerosis (MS).

OBJECTIVES

The CoSMo study evaluated the association between CCSVI and MS.

METHODS

The primary end-point of this multicentric, case-control study was to compare the prevalence of CCSVI between patients with MS, patients with other neurodegenerative diseases (ONDs) and healthy controls (HCs). Color-coded duplex sonography was performed by a sonologist and the images were sent to one of three central sonologists for a second reading. Agreement between local and central sonologists or, in case of disagreement, the predominant judgment among the three central readers, was required for a diagnosis of CCSVI. All readings, data collection and analysis were blinded.

RESULTS

The study involved 35 MS centers across Italy and included 1874 subjects aged 18-55. 1767 (94%) were evaluable: 1165 MS patients, 226 patients with ONDs and 376 HCs. CCSVI prevalence was 3.26%, 3.10% and 2.13% for the MS, OND and HC groups, respectively. No significant difference in CCSVI prevalence was found amongst the three cohorts (MS versus HC, OR = 1.55, 95%CI = 0.72-3.36, p = 0.30; OND versus HC, OR = 1.47, 95%CI = 0.53-4.11, p = 0.46; MS versus OND, OR = 1.05, 95%CI = 0.47-2.39, p = 0.99). High negative and low positive agreement was found between the local and centralized readers.

CONCLUSIONS

CCSVI is not associated with MS.

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.

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.

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.

Chronic cerebrospinal venous insufficiency is not associated with multiple sclerosis and its severity: a blind-verified study

BACKGROUND

Chronic Cerebrospinal Venous Insufficiency (CCSVI) has been associated with multiple sclerosis (MS) with a risk ranging from as high as two-hundred-fold to a protective effect. However, not all studies were blinded, and the efficacy of blinding was never assessed.

OBJECTIVE

To evaluate the association of CCSVI with MS in a cross-sectional blinded study and look for any association of CCSVI with the severity of MS.

METHODOLOGY/PRINCIPAL FINDINGS

The Echo-color Doppler examination was carried out in accordance with Zamboni's five criteria in 68 consecutive MS patients and 68 healthy controls, matched by gender and age (±5 years). Four experienced neurosonologists, blinded to the status of cases and controls, performed the study and were then asked to guess the status (case or control) of each participant. The number of positive CCSVI criteria was similar in the two groups. CCSVI, defined as the presence of two or more criteria, was detected in 21 cases (30.9%) and 23 controls (33.8%), with an OR of 0.9 (95%CL = 0.4-1.8, p = 0.71). The prevalence of CCSVI was related to age in cases (OR increasing from 0.2 to 1.4), but not in controls. CCSVI positive (N = 21) and negative (N = 47) MS patients were similar in clinical type, age at disease onset, disability, and fatigue. Disease duration was longer (16.5±9.8 years) in CCSVI positive than negative patients (11.5±7.4; p = 0.04). The operators correctly guessed 34/68 cases (50%) and 45/68 controls (66%) (p = 0.06), indicating a different success of blinding.

CONCLUSIONS/SIGNIFICANCE

CCSVI was not associated with MS itself, nor its severity. We cannot rule out the possibility that CCSVI is a consequence of MS or of aging. Blinding of sonographers is a key point in studying CCSVI and its verification should be a requisite of future studies.