Patients who showed evidence of CCSVI were further evaluated by selective venography. Fifty MS-matched normal controls (NC), 60 patients with transient global amnesia (TGA), and 60 TGA-matched NC were studied. Transcranial venous echo-color Doppler was normal in all patients with CIS. One or more abnormal extracranial venous echo-color Doppler findings were observed in 26 of 50 (52.0%) of the patients with CIS, 35 of 110 (31.8%) of the controls

and 41 of 60 (68.3%) of the patients with TGA. The eight (16%) patients with CIS who fulfilled the diagnosis of CCSVI were further evaluated blindly by selective venography, which did not learn more disclose any venous anomalies. Thus, we could not demonstrate any causative effect of CCSVI on MS [14]. The second study INCB024360 mouse was focused on the progressive forms of MS, to investigate whether CCSVI could play a role in determining disease progression. We analyzed 60 patients with chronic progressive forms of MS (35 SP, 25 PP) and 60 age-/gender-matched NC. TCDS was normal in all patients. ECDS showed

one or more abnormal findings in 9/60 (15.0%) patients [7/35 (20.0%) SPMS, 2/25 (8.0%) PPMS] and in 14/60 (23.3%) NC (p not significant for all comparisons). CCSVI criteria were fulfilled in 0 NC and 4 (6.7%) MS patients: 3 SPMS and 1 PPMS. VGF, performed blindly in 6/9 patients, was abnormal only in one case that had bilateral internal jugular vein (IJV) stenosis [17]. These findings indicate that CCSVI is not a late secondary phenomenon of MS and is not responsible for disability progression. On the basis of these contradictory results, it is absolutely necessary to question the validity of the five ultrasound criteria proposed by Zamboni for the diagnosis of CCSVI. In the first criterion, Zamboni et al. used the threshold value of 0.88 s to Sclareol discriminate IJV and vertebral vein (VV) physiological back flow due to valve closure from pathological reflux without performing the Valsalva maneuver

(VM) [8] and they found that 71% of MS patients had a pathological reflux vs. 0% of controls. This threshold value comes from a totally different study on IJV valve insufficiency during a controlled VM [20] where it was chosen to differentiate VM-induced insufficiency through insufficient valves lasting >1.23 s, from physiological backward flows during normal valve closure, lasting 0.22–0.78 s. In this study it was found that about 30% of normal subjects have a physiological (t < 0.88 s) back flow during normal valve closure. Furthermore, the utilization of this threshold by Zamboni for assessing reflux in other vessels (i.e. VVs) other than IJV valve insufficiency is also scientifically incorrect. For the second criterion, the intracranial veins and sinuses were not examined through the transtemporal bone window for which there are published ultrasound criteria and velocity data [21] and [22]. Zamboni et al.