title: Chronic cerebrospinal venous insufficiency is not associated with multiple sclerosis and its severity: a blind-verified study.
abstract: 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.
  
  
  RESULTS
  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
  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.
authors: MS Centre, Head and Neck Department, AOU Maggiore della Carità, Novara, Italy. maurizio.leone@maggioreosp.novara.it
authors: Maurizio A
authors: MA
authors: Leone
authors: Olga
authors: O
authors: Raymkulova
authors: Paola
authors: P
authors: Naldi
authors: Piergiorgio
authors: P
authors: Lochner
authors: Laura
authors: L
authors: Bolamperti
authors: Lorenzo
authors: L
authors: Coppo
authors: Alessandro
authors: A
authors: Stecco
authors: William
authors: W
authors: Liboni
mesh_terms: D000328:Adult; D002560:Cerebrovascular Circulation; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications* / Q000000981:diagnostic imaging; D011446:Prospective Studies; D012720:Severity of Illness Index; D013116:Spinal Cord / Q000000981:diagnostic imaging*; D017585:Ultrasonography, Doppler, Transcranial; D014689:Venous Insufficiency / Q000150:complications* / Q000000981:diagnostic imaging