Background and purpose: Former studies reported internal jugular vein stenosis in patients with multiple sclerosis. We aimed to evaluate if these venous stenoses were real and cerebral venous outflow of patients with multiple sclerosis differed from that of normal controls.
Methods: 20 controls were prospectively investigated by angiography and duplex ultrasound. Seven patients with multiple sclerosis underwent angiography at other centers; we reviewed these registrations and performed venous ultrasound examinations.
Results: Angiography displayed > 50% stenosis of internal jugular vein in 19 controls (69 ± 17% on the right and 73 ± 13% on the left side) and < 50% stenosis in 1 control (43.5% and 44.6%). All 7 patients had at least one-sided stenosis. The mean degree of stenosis was 63 ± 16% on the right and 67 ± 13% on the left side. There was no significant difference in the degree of stenosis between patients and controls. However, these "stenoses" disappeared if the contrast agent was injected at a catheter position below the orifice of the subclavian vein during venography. The venous flow volume was also similar between groups: 479.7 ± 214.1 and 509.8 ± 212.0 ml/min (right and left side) in the patients and 461.3 ± 224.3 and 513.6 ± 352.2 ml/min in the control group; p = 0.85 and 0.98 (right and left). Color and power duplex imaging also revealed normal blood flow of the internal jugular vein in all patients and controls.
Conclusion: The cerebral venous status of patients with multiple sclerosis and controls were similar. The angiographic "stenoses" were virtual, caused by the contrast dilution effect of the non-contrast blood stream of the subclavian vein.