Dilatation of the bridging cerebral veins in multiple sclerosis correlates with fatigue and suggests an increase in pressure

Background: There is a significant increase in the parenchymal microvessel blood volume in the earliest forms of multiple sclerosis (MS) which may be due to venular dilatation. Increased cortical venous pressure could account for this finding. Venous pressure is also implicated in the physiology of fatigue. The purpose of this study is to discover if there is dilatation of the veins within the subarachnoid space in multiple sclerosis and to estimate the pressures required to maintain any enlargement found. These findings will be correlated with the fatigue symptoms found in MS. Methods: 103 patients with MS were compared with a control group of 50 patients. Post contrast 3DT1 images were used. The cross-sectional area of the bridging cortical veins and the vein of Galen were measured. Results: In MS, the superficial territory cortical veins were 29% larger and the veins of Galen were 25% larger than the controls. Conclusion: There is evidence of a significant increase in the bridging vein transmural pressure in MS, estimated to be approximately 6.5 mmHg in the superficial cortical veins. MS patients with significant fatigue have larger cortical veins than those who are not significantly fatigued.