Multiple sclerosis (MS) is characterized by demyelination centered around cerebral veins. Recent studies suggested this topographic pattern may be caused by venous congestion, a condition termed chronic cerebrospinal venous insufficiency (CCSVI). Published sonographic criteria of CCSVI include reflux in the deep cerebral veins and/or the internal jugular and vertebral veins (IJVs and VVs), stenosis of the IJVs, missing flow in IJVs and VVs, and inverse postural response of the cerebral venous drainage.
We performed an extended extra- and transcranial color-coded sonography study including analysis of extracranial venous blood volume flow (BVF), cross-sectional areas, IJV flow analysis during Valsalva maneuver (VM), and CCSVI criteria. Fifty-six MS patients and 20 controls were studied.
Except for 1 patient, blood flow direction in the IJVs and VVs was normal in all subjects. In none of the subjects was IJV stenosis detected. IJV and VV BVF in both groups was equal in the supine body position. The decrease of total jugular BVF on turning into the upright position was less pronounced in patients (173 ± 235 vs 362 ± 150ml/min, p < 0.001), leading to higher BVF in the latter position (318ml/min ± 242 vs 123 ± 109ml/min; p < 0.001). No differences between groups were seen in intracranial veins and during VM. None of the subjects investigated in this study fulfilled >1 criterion for CCSVI.
Our results challenge the hypothesis that cerebral venous congestion plays a significant role in the pathogenesis of MS. Future studies should elucidate the difference between patients and healthy subjects in BVF regulation. ANN NEUROL 2010;68:173–183