A Study of Dural Arteriovenous Fistula with Leptomeningeal Venous Drainage and No Low Perfusion Area by CBF SPECT Study

When dural arteriovenous fistula (DAVF) is associated with leptomeningeal venous drainage (LMVD), most cases have venous hypertension and concomitant venous congestion in the same areas due to reduced venous circulation. On the other hand, some cases in the DAVF with LMVD have no low-perfusion area. We studied this phenomenon. The subjects were 25 patients with DAVF. Of them, 16 cases had LMVD. Eleven had a low-perfusion area but 5 had no low-perfusion area. We analyzed this phenomenon in 5 cases. Two cases had anterior cranial fossa DAVF, 2 had tentorium DAVF, and 1 had transverse-sigmoid sinus DAVF. The characteristics of these DAVF are: 1) extra-sinusal type or pure leptomeningeal venous drainage, 2) low shunt flow, 3) existence of accessory route.