Reports from seven multi-disciplinary teams investigating CCSVI (chronic cerebrospinal venous insufficiency) in MS indicate that they are making good progress toward providing essential data and critical analysis as these two-year projects move toward their completion. The studies were launched on July 1, 2010 with a more than $ 2.4 million commitment from the MS Society of Canada and the National MS Society (USA). The ongoing work by the seven teams will help inform the design of an early-phase clinical trial that is expected to launch in late spring 2012 with funding from the MS Society of Canada and the Canadian Institutes of Health Research (CIHR).
The research teams have recruited and scanned a broad spectrum of people with MS and others to build understanding of who may be affected by CCSVI. In addition they are refining CCSVI imaging methods for accuracy and consistency to reliably validate the occurrence of CCSVI and understand its implications in the MS disease process. All of the seven teams are working under approvals from the required Institutional Review Boards in the U.S. or the Research Ethics Board in Canada, a first step established by regulatory authorities to protect human subjects involved in research projects. (Read more about steps involved in conducting clinical research.)
Already more than 800 people have undergone scanning with various imaging technologies being used by the studies, including the Doppler ultrasound technology used by Dr. Paolo Zamboni and his collaborators, as well as magnetic resonance studies of the veins (MR venography), catheter venography, MRI scans of the brain, and clinical measures.
Representatives of each of the seven funded teams are part of the CIHR’s Scientific Expert Working Group. In November 2011 the Canadian Institutes of Health Research (CIHR) announced the release of a Request for Proposals seeking grant applications from researchers to conduct an early-phase clinical trial in Canada to test the ability of a surgical procedure called balloon venoplasty to improve blood drainage in individuals with MS who have been identified as having CCSVI. The request for research proposals is a collaborative initiative between the CIHR and the MS Society of Canada. The working group will provide leadership and advice concerning the clinical trial, and will continue to monitor and analyze the data from the seven studies and other studies related to CCSVI and MS around the world.
Several teams have presented, or are planning to present, preliminary results at medical meetings. Because the studies employ rigorous blinding and controls designed to collect objective and comprehensive data, the full results of the ongoing research will be available only after completion of the studies which will involve more than 1300 people representing a spectrum of MS types, severities and durations, as well as individuals with other disease types and healthy controls.
“The research underway is significantly advancing our understanding of CCSVI and what its relationship might be to MS disease process,” notes Dr. Tim Coetzee, chief research officer at the National MS Society. Dr. Karen Lee, Vice President Research at the Canada MS Society, concurs, “We are pleased that our collaborations with the National MS Society and CIHR are moving us closer to the answers that people with MS need about CCSVI and MS.”
Details of Progress
The funded investigators, who are drawn from a broad range of disciplines ranging from MS neurology, vascular surgery and interventional radiology, report progress in establishing standardized protocols, recruiting and scanning participants and in the development of plans for sharing their findings, as summarized below.
- Dr. Brenda Banwell, The Hospital for Sick Children, Toronto, Ontario: Dr. Banwell’s team is seeking confirmation for findings that Cerebrospinal Venous Insufficiency is a cause for Multiple Sclerosis (MS). If impaired venous drainage occurs as a key part of the beginnings of the MS process, then venous abnormalities should be present even in the youngest MS patients. The team is now studying children and teenagers with MS to determine whether the venous system is abnormal in a population where the disease process is at a very early stage. Unlike adult MS patients, children are very unlikely to have any age-related changes in blood vessels, and do not have any of the adult-onset health conditions (such as high blood pressure, heart disease, use of medications) that might complicate the ability to determine whether blood flow patterns are due to MS or other causes. Their ultrasound team has received training from Dr. Zivadinov’s group in Buffalo, and has created ultrasound and brain imaging procedures suited to explore venous drainage in children. They plan to assess 30 children with MS, 30 healthy children of the same age, and 30 “graduates” (young adults who experienced the onset of MS during childhood and who received care and prior brain imaging studies at the Hospital for Sick Children). Enrollment began in December 2010 and Dr. Banwell’s team has reported that it is going well. To ensure the highest standards of scientific accuracy, they intend to analyze their findings once all 90 participants have undergone the testing; which will help to determine whether impaired venous drainage is indeed a core component of MS.
- Dr. Fiona Costello, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta The University of Calgary team has initiated a prospective cross-sectional study to determine the association between ultrasonography (US) and magnetic resonance venography (MRV) measures of venous outflow in MS patients. This study will evaluate 120 people with MS (including 65 with relapsing-remitting MS, 20 with secondary-progressive MS, 10 with primary-progressive MS, 10 with neuromyelitis optica, and 15 with pediatric MS) and 60 age- and sex-matched healthy control subjects. To date, 98 participants have been recruited. The main outcome measure will be the proportion of cases and controls with US and MRV evidence of extracranial venous outflow obstruction. Secondary outcomes will include MRI measures of brain inflammation, Expanded Disability Status Scale (EDSS) scores, and extracranial US measures of venous wall thickening and jugular valve competence. The team published a paper based on the cases of five people who had experienced medical complications after undergoing procedures focused on treatment of venous abnormalities: “Complications in MS Patients after CCSVI Procedures Abroad.” Burton JM, Alikhani K, Goyal M, Costello F, White C, Patry D, Bell R, Hill M. (Calgary, AB) Can J Neurol Sci 2011 Sep;38(5):741-6.
- Dr. Aaron Field, University of Wisconsin School of Medicine and Public Health, Madison: Official approval of this study protocol was issued on June 28, 2011. The team continues to actively recruit study subjects from a database of approximately 100 MS patients who had contacted them since the study was first announced, as well as from the patient population seen regularly in their MS clinic. Thus far, 17 people with MS and 12 healthy controls have undergone both MRI/MRV and ultrasound imaging. No results are yet available as the study is blinded. Since the previous progress report, Dr. Field was awarded a $27,000 grant from his institution to further investigate the novel MRI components of this study in healthy controls, particularly with regard to reliability and reproducibility. Specifically, they investigated (1) the use of a novel method to adjust venous flow measurements for variations related to breathing and heartbeat, (2) the use of a novel MRI method for measuring the iron content in brain tissue, and (3) the use of a relatively new, FDA-approved MRI contrast agent (a drug administered intravenously to enhance the visibility of blood vessels on MRI) that can enhance the visibility of head/neck veins and enable the measurement of blood flow through brain tissue. Ten healthy subjects underwent these components of the team’s CCSVI protocol twice, on separate days. Progress made in these studies includes:
- The team’s novel approach to measuring venous flow with MRI is able to detect clear differences in venous flow between inspiration and expiration, and demonstrates evidence of expiration-related reflux (backwards flow) in the jugular veins of healthy subjects.
- The team’s system of rating the degree of venous narrowing on MR images of the azygous and jugular veins yields comparable results when performed by different individuals.
- Their novel MRI method for measuring iron content in brain tissue provides reproducible results that are comparable to previously described methods of iron measurement, with fewer technical pitfalls.
- A single dose of a relatively new MRI contrast agent is sufficient to enhance the visibility of head/neck veins and generate reproducible maps of blood flow through the brain. (It would normally require two separate doses of a conventional contrast agent to accomplish both of these objectives.)
“Comprehensive assessment of cerebral venous return with MRA: preliminary results.” Wieben O, Johnson K, Schrauben E, Reeder S, Field A. 23rd annual meeting of the “MRA Club” (International Magnetic Resonance Angiography Workshop), Calgary, Alberta, Canada, September 25-28, 2011. “The importance of the sonographer in the investigation of chronic cerebrospinal venous insufficiency.” Kohn S, Kliewer K, Field AS. American Institute of Ultrasound in Medicine (AIUM) Annual Convention, Phoenix, AZ, March 29-April 1, 2012. In addition, three abstracts have been submitted for consideration for the American Society of Neuroradiology (ASNR) 50th Annual Meeting, New York, NY, April 21-26, 2012, and two have been submitted for the International Society of Magnetic Resonance in Medicine (ISMRM) 20th Annual Meeting & Exhibition, Melbourne, Victoria, Australia, May 5-11, 2012. - Dr. Robert Fox, Cleveland Clinic Foundation, Cleveland: Dr. Fox’s team continues to use MR venography, ultrasound, MRI and clinical measures in people with MS or who are at risk for MS (CIS) and comparison groups to evaluate vein drainage. The ultrasound team, which underwent training in the technique originally used by Dr. Zamboni, found several aspects of the published methodology ambiguous, and they have standardized the protocol and analysis to achieve consistent results. Early on they identified physiological and technical factors that can complicate screening for vein blockages using ultrasound, including that heartbeat irregularities, stages of breathing, head position and pressure applied by the operator could alter results; and that the state of hydration of the subject (whether they drank adequate amounts of fluids) might impact results of several of the criteria used to determine CCSVI. The team reported at the international ECTRIMS/ACTRIMS congress in October 2011 preliminary results of ultrasound assessments. Pooling the results of the ongoing, blinded study of CCSVI in MS and non-MS controls, they reported results from the first 20 subjects, finding that 6 (30%) met criteria for CCSVI, four subjects met no criteria, and none met criteria for reverted postural control of cerebral venous outflow. Nine subjects (45%) had a flap and/or septum/abnormal valve. Identifi¬cation of deep cerebral vein reflux depended upon the ultrasound technique. They noted that this finding highlights the importance of ultrasound methodology in performing and interpreting deep cerebral vein assessments. At the same ECTRIMS/ACTRIMS meeting, the team shared preliminary results from an ongoing study of vein structure in autopsy specimens from seven people who had MS in their lifetimes, compared to six people who did not have MS. In this unblinded study, they identified abnormalities inside the vein tubes (lumen) that drain the brain and found a variety of structural abnormalities and anatomic variations in both groups. However, they reported higher frequency of abnormalities in those who had MS (2 abnormalities in 2 out of 6 controls versus 9 abnormalities in 6 out of 7 MS patients). They noted that MR venography may be less effective than ultrasound for identifying these venous abnormalities, and that ultrasound that examines only vein wall circumference may miss some intraluminal abnormalities.
- Dr. Carlos Torres, The Ottawa Hospital, University of Ottawa, Ontario: The team began phase 1 of their project which consists of imaging with MRI the veins of the head and neck of 100 people without MS. MR venography is also being performed to obtain normative data that will allow the team to better understand the normal anatomy and variants of the veins before they begin to examine the veins of the subjects and controls. So far, they have performed this additional sequence in 85 people and expect to complete the target of 100 within the next 2 weeks. Further, they have gathered MRI studies of 30 people with a specific sequence that allows them to measure the amount of iron in the brain. The iron deposits are being quantified by an MR Physicist. In order to perform the ultrasound studies of the veins in the head and neck the same way they were done as described by Dr. Zamboni, the team received training in Vancouver from an experienced group who received training in Italy. Two sonographers and a radiologist traveled to Vancouver and received appropriate training on the technique in mid-May. In early September, the team reported that they successfully started phase 2 of the study recruiting subjects and controls through the Ottawa Hospital MS Research Unit. Since then, they have recruited a total of 30 people with MS (with relapsing-remitting, primary-progressive or secondary-progressive MS) and 30 controls (60 total), who have undergone both a contrast enhanced MRI and an ultrasound of the veins of the head and neck. The team is currently scanning approximately 4 people with MS and 4 controls per week. They expect to complete recruitment and begin analysis of the data by mid February 2012.
- Dr. Anthony Traboulsee, UBC Hospital MS Clinic, UBC Faculty of Medicine and Dr. Katherine Knox, Saskatoon MS Clinic, University of Saskatchewan: This team is conducting their study at two centers (UBC Hospital, Vancouver, BC and Saskatoon City Hospital, Saskatoon, Sask.) and the goal is to recruit up to 200 subjects. Imaging protocols have been both developed and tested and the group is very satisfied with the quality of their results. Their ultrasound technologists were trained by Dr. Zamboni to perform the ultrasound testing in a similar way. There is no previous standardized venography protocol for looking at neck veins. Recruitment is now closed at the University of British Columbia site, and will be closing soon at the Saskatoon site. All investigations are expected to be completed in March 2012. The team plans to do the preliminary analysis by April 2012. Analysis will occur in stages, starting with the catheter venography and ultrasound data, then the MR venography results will be reviewed. The team reported that the level of interest and response rate remained high throughout recruitment. The UBC site recruited 110. At the Saskatoon site, 70 subjects have been recruited and are at various stages of the protocol. All investigators remain blinded to the status of the subjects and do not have any preliminary results to report at this time.
- Dr. Jerry Wolinsky, University of Texas Health Science Center at Houston: The team reports that they have recruited about 82% of the expected study cohort. The cumulative number of volunteers recruited from study inception includes: 10 Healthy Volunteers; 34 Other Neurological Diseases; 22 Stroke/TIA; 12 CIS; 112 relapsing-remitting MS; 44 secondary-progressive MS; 1 progressive-relapsing MS; 15 primary-progressive MS. Of people with MS or CIS, 45 have undergone MR venography with advance MRI. In addition, to date 10 people with MS have consented to transluminal venography, 2 are scheduled for study and 4 have completed the procedure without complications. No therapeutic interventions are considered in these investigations. Dr. Wolinsky and the team’s MR vascular expert, Dr. Larry Kramer, are members of the MS Scientific Expert Working Group established by the Canadian Institutes of Health Research (CIHR), in collaboration with the Multiple Sclerosis (MS) Society of Canada, and additional team members have participated in the meetings and provided advice to the CIHR as requested. A summary of the team’s preliminary work was presented as a poster at the international ECTRIMS/ACTRIMS congress in October 2011. They used Doppler technology to evaluate venous drainage in a blinded fashion. They reported that of all participants, 48/162 fulfilled at least one of five criteria for anomalous venous outflow proposed by Dr. Zamboni; 10/48 fulfilled two criteria consistent with CCSVI; none fulfilled more than 2 criteria. There was no significant difference between people with MS and non-MS, or within MS subgroups. They also found no significant differences between MS and non-MS subjects for measures of cross-sectional areas of the internal jugular veins or for venous flow rates. The team concluded that thus far they find less CCSVI than previously reported by other groups. They are now focusing on whether ultrasound can be complemented or supplanted by MRV and/or transluminal venography. In addition, two abstracts have been submitted for consideration for the 64th Annual Meeting of the American Academy of Neurology to be held in late April 2012.
Going Forward
These seven teams were chosen by an international panel of experts that included specialists drawn from all key relevant disciplines including radiology, vascular surgery and neurology. The projects were selected for having the greatest potential to quickly and comprehensively determine the significance of CCSVI in the MS disease process.
At this 18-month milepost, the investigators are making significant progress on their overall two-year study goals. Some of the teams are presenting preliminary results at medical meetings, and all have shared technical advice so that the projects can move forward as smoothly and quickly as possible. Their results will help guide the development of an early-phase clinical trial to test whether treating vein blockages may be safe and effective in treating people with MS. The trial should launch in late spring 2012 with funding from the MS Society of Canada and the Canadian Institutes of Health Research (CIHR).
The next update on the work of the seven grantees will be reported in six months.