ABSTRACT: IntroductionTransverse sinus tapered narrowings are frequently identified in patients with idiopathic intracranial hypertension (IIH);
however, it remains unclear whether they are primary stenoses or whether they occur secondary to raised cerebrospinal fluid
pressure. Computed tomographic venography demonstrates both the morphology of the venous system and the adjacent bony grooves
so it may provide an insight into the aetiology of these transverse sinus stenoses.
Materials and methodsTapered transverse sinus narrowings (>50%) were studied in 19 patients without IIH and 14 patients with IIH. Computed tomography
vascular studies were reviewed and the dimensions of the venous sinuses and bony grooves at the sites of maximum and minimum
transverse sinus area dimensions were recorded.
ResultsThere was demonstrated to be a strong correlation of bony groove height with venous sinus height at the largest portions of
the transverse sinus in both IIH patients and non-IIH subjects as well as at the transverse sinus narrowing in non-IIH subjects.
There was a discordant relationship between bony groove height and venous sinus height at the site of transverse sinus stenoses
in IIH patients. In 5/23 IIH transverse sinus stenoses, the bony groove height was proportionate to that seen in non-IIH subjects.
There were a further 8/23 cases where the small or absent sinus was associated with an absent bony groove.
ConclusionTransverse sinus tapered narrowings in subjects without IIH and in the majority of patients with IIH were associated with
proportionately small or absent grooves, and these are postulated to be primary or fixed. Some patients with IIH demonstrate
tapered transverse sinus stenoses with disproportionately large bony grooves, suggesting a secondary or acquired narrowing.
This implies a varied aetiology for the transverse sinus stenoses of IIH.
Neuroradiology 04/2012; 50(12):999-1004. · 2.82 Impact Factor