Dural Venous Sinus Variations in Idiopathic Subarachnoid Hemorrhage: A New Indicator of the Venous Origin with Diagnostic Usefulness?

OBJECTIVE: Venous hypertension associated with a primitive basal vein of Rosenthal (BVR) has been noted as the most likely cause of idiopathic subarachnoid hemorrhage (iSAH). Other types of venous drainage variations have been scarcely studied but may further explain the cases not associated with a BVR anomaly. Our aim was to investigate if dural venous sinus (DVS) anomalies are related with iSAH. METHODS: A total of 76 patients diagnosed with iSAH were identified from a prospectively maintained database and their angiographic findings compared with 76 patients diagnosed with aneurysmal subarachnoid hemorrhage. RESULTS: On top of the BVR variations, our data showed a higher prevalence of transverse sinus hypoplasia (47.4% vs. 28.9%; P = 0.019), superior petrosal sinus hypoplasia (32.9% vs. 13.2%; P = 0.003), and clival plexus hyperplasia (65.8% vs. 43.4%; P = 0.005) in patients with iSAH. Analyzing by total number of angiograms, the iSAH group showed also a higher prevalence of inferior petrosal sinus hyperplasia (36.2% vs. 25%; P = 0.003). Of the patients with iSAH without a primitive BVR, 84% harbored ≥1 perimesencephalic DVS variation and the overall number of venous drainage variations was significantly higher in patients with iSAH. CONCLUSIONS: In addition to the well-documented BVR anomalies, there seems to be a significant relationship of other DVS variations in patients with iSAH. Transverse sinus hypoplasia, superior petrosal sinus hypoplasia, inferior petrosal sinus hyperplasia, and clival plexus hyperplasia were significantly more frequent in patients with iSAH. The presence of ≥3 of those variations would increase the suspicion of a nonaneurysmatic subarachnoid hemorrhage and could help avoid a second angiogram.

Relationship between venous drainage subtypes and sub-arachnoid hemorrhage subtypes: a meta-analysis.

BACKGROUND: To investigate whether associations exist between venous drainage subtypes (types I, II, and III) and the risk of subarachnoid hemorrhage subtypes. METHODS: Published case-control and case series from 2010 to 2014 which met all the inclusion criteria for the meta-analysis were selected and subjected to rigorous statistical analysis. RESULTS: A total of 11 studies with an overall patient population (case and controls) of 891 were involved in the study. Types I and II venous drainage had odds against peri-mesencephalic subarachnoid hemorrhage. The odds were in favor of type III venous drainage and peri-mesencephalic sub-arachnoid hemorrhage and idiopathic sub-arachnoid hemorrhage (ISAH). CONCLUSIONS: Type I deep venous drainage may not be associated with the risks of peri-mesencephalic subarachnoid hemorrhage and ISAH, however, types II and III may be associated with high risk of peri-mesencephalic subarachnoid hemorrhage and ISAH, respectively.