title: Observational case-control study of the prevalence of chronic cerebrospinal venous insufficiency in multiple sclerosis: results from the CoSMo study.
abstract: BACKGROUND
  Chronic cerebrospinal venous insufficiency (CCSVI) has been proposed as a possible cause of multiple sclerosis (MS).
  
  
  OBJECTIVE
  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.
authors.affiliation: Department of Neurology, Università Vita Salute San Raffaele, Milan, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Comi
authors.forename: M A
authors.initials: MA
authors.lastname: Battaglia
authors.forename: A
authors.initials: A
authors.lastname: Bertolotto
authors.forename: M
authors.initials: M
authors.lastname: Del Sette
authors.forename: A
authors.initials: A
authors.lastname: Ghezzi
authors.forename: G
authors.initials: G
authors.lastname: Malferrari
authors.forename: M
authors.initials: M
authors.lastname: Salvetti
authors.forename: M P
authors.initials: MP
authors.lastname: Sormani
authors.forename: L
authors.initials: L
authors.lastname: Tesio
authors.forename: E
authors.initials: E
authors.lastname: Stolz
authors.forename: P
authors.initials: P
authors.lastname: Zaratin
authors.forename: G
authors.initials: G
authors.lastname: Mancardi
mesh_terms: D000328:Adult; D001921:Brain / Q000098:blood supply*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications / Q000453:epidemiology*; D015995:Prevalence; D013116:Spinal Cord / Q000098:blood supply*; D014689:Venous Insufficiency / Q000150:complications / Q000453:epidemiology*
keywords: Chronic cerebrospinal venous insufficiency; Italy; circulatory system; multicentric study; multiple sclerosis; neurodegenerative disease; prevalence study; sonography