Asymmetric cavernous sinus enlargement: a novel finding in Sturge-Weber syndrome.

PURPOSE: Enlargement of deep cerebral veins and choroid plexus engorgement are frequently reported in Sturge-Weber syndrome. We aim to describe cavernous sinus involvement in patients with this syndrome and to identify possible clinical-neuroimaging correlations.

METHODS: Sixty patients with Sturge-Weber syndrome (31 females, mean age 4.5 years) and 120 age/sex-matched controls were included in this retrospective study. We performed a visual analysis to identify patients with asymmetric cavernous sinus enlargement. Then, we measured on axial T2WI the left (A), right (B), and bilateral (LL) transverse diameters of the cavernous sinus. We calculated the module of the difference |A-B| and the cavernous sinus asymmetry index as the ratio |A-B|/LL. Differences among groups were assessed by Mann-Whitney U and Kruskal-Wallis tests. Clinicoradiological associations were evaluated by Fisher exact test.

RESULTS: We found seven subjects (11.6%) with asymmetric CS enlargement. The |A-B| and cavernous sinus asymmetry index were higher in patients with asymmetric CS enlargement compared with controls and patients without visible CS abnormalities (pB  < 0.05). Asymmetric CS enlargement was always ipsilateral to facial port-wine stains (7/7), and, when present, to leptomeningeal vascular malformations (4/7). It was significantly associated with ipsilateral bone marrow changes (p = 0.013) and dilated veins (p = 0.002). Together with brain atrophy and deep venous dilatation, this sign was associated with neurological deficits (p < 0.05).

CONCLUSIONS: We expanded the spectrum of venous abnormalities in SWS, showing the presence of asymmetric cavernous sinus enlargement in more than one tenth of patients, likely related to increased venous drainage.