Darren Klass MD, PhD, Presenter: Nothing to Disclose

1) Discuss the incidence of MS and its impact on healthcare in Canada. 2) Discuss the design of the assessor-blinded, case controlled study and the difficult task of ensuring the strict blinding protocol was adhered to. 3) Discuss the findings, the strength of the blinding in the study and the impact of the study results on future interventional radiology studies related to the subject. 4) Discuss the importance of working in a well-functioning interventional radiology team. This session is part of Canada Presents at RSNA 2014.

Background Chronic cerebrospinal venous insufficiency has been proposed as a unique combination of extracranial venous blockages and haemodynamic flow abnormalities that occur 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: An assessor-blinded, case-control, multicentre study of people with multiple sclerosis, unaffected siblings, and unrelated healthy volunteers was conducted. Study participants were enrolled 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. Catheter venography data were available for 149 participants and ultrasound data for 171 participants. Findings: This study revealed a low incidence of chronic cerebrospinal venous insufficiency in all groups; 2% of people with multiple sclerosis, 2% of siblings and 3% of unrelated controls (p=1·0 for all comparisons). Greater than 50% narrowing of any major vein was present in 74% of people with multiple sclerosis, 66% of siblings (p=0·41 for comparison with patients with multiple sclerosis), and 70% of unrelated controls (p=0·82). The ultrasound criteria were fulfilled in 44% of participants with multiple sclerosis, 31% of siblings (p=0·15 for comparison with patients with multiple sclerosis) and 45% of unrelated controls (p=0·98). Conclusions: 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. The significance of venous narrowing to multiple sclerosis symptomatology remains unknown.

Klass, D, Prevalence of Extracranial Venous Narrowing on Catheter Venography in People with Multiple Sclerosis, Their Siblings, and Unrelated Healthy Controls: A Blinded, Case-control Study.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14019845.html