One of the advantages of our study was the large number of participants in the study compared to previous researches, 84 patients with MS and 115 healthy controls. Most of the participants in our study were RRMS and SPMS, with a small percentage of PPMS. We recommend future studies to include other types of MS in the evaluation to check for differences between all types of the disease. As there is controversy between different studies assessing CCSVI criteria in MS patients and above-mentioned reports about IJV resection consequences, reconsidering the criteria may be an option. Another reason for these controversies might be differences

in techniques, instruments, anatomical site and patient’s position when performing sonography, which can be decreased by using the same method and mode of sonography. The person who performed sonographic evaluations was not blind to patient’s group in our gamma aminobutyric acid function study. Blinding the assessors also can decrease the bias in the future studies. The authors would like to thank Dr. Jalil Kouhpayezadeh for his confidential

supports in statistical procedures and sample size calculation. Also we would like to appreciate the staff of Firoozgar Clinical Research Development Center (FCRDC) for their technical supports and helps. “
“Optic Neuritis (ONe) is a common feature of Multiple Sclerosis (MS) both in the early phase and during the disease course [1]. ABT-737 chemical structure MS and ONe are due to demyelination [2], but it has been postulated Fossariinae that vascular mechanisms may have a role in MS and

ONe pathogenesis [3], [4], [5] and [6]. According to a recent hypothesis, cerebrospinal venous system alterations may contribute to the development of the disease and may drive its clinical course [7] and [8]. As a matter of fact, a correlation between the hemodynamic pattern of Chronic Cerebrospinal Venous Insufficiency (CCSVI) and the clinical features in patients with MS has been described [9]. In particular, ONe at onset seems to be associated with Internal Jugular Veins (IJV) and/or of proximal Azygous Vein (AV) high grade stenosis, with consequent reflux in the deep cerebral veins. The blood then flows to the pterygoid plexus, and from there to the facial veins via the deep facial vein, to the cavernous sinus and to the ophthalmic veins. While changes in the hemodynamics of the eye’s arterial system, detected by Doppler ultrasound sonography, have been previously described in MS patients with both acute and chronic ONe [10], [11], [12] and [13], the venous flow has not been studied yet, as far as we know. Taking into account the peculiar environment of the arterial-venous system supplying and draining the Optic Nerve, we have considered it as a representative site for studying the relationship between veins and nervous parenchyma.