Transverse sinus stenoses in benign intracranial hypertension demonstrated on CT venography.

Catheter studies show that patients with benign intracranial hypertension (BIH) frequently have high pressures in the intracranial venous sinuses proximal to stenotic lesions in the transverse sinuses. These lesions have now been demonstrated on MR venography. This study investigated whether they would be visible on CT. CT venography was performed on 10 patients with BIH and compared with 10 controls, matched for age and sex, undergoing CT angiography for subarachnoid haemorrhage. All controls were confirmed to have had ruptured intracranial aneurysms at craniotomy. Using a semi-automated technique to develop a profile of the cross-sectional areas along the lateral sinuses and to minimize observer bias, the narrowest point on each side was identified and summated in every subject. All patients with BIH exhibited a region of marked narrowing in both transverse sinuses, usually near the junction with the sigmoid sinus, rarely seen in our control group. Measured cross-sectional areas in these venous outflow tracts were substantially different between patients with BIH and controls (p<0.001). CT venography frequently demonstrates transverse sinus narrowing in BIH.