Progress in research on intracranial multiple dural arteriovenous fistulas

Intracranial multiple dural arteriovenous fistulas (MDAVFs) are rare lesions that are difficult to treat. The key factors involved in the development of MDAVFs remain unknown. At present, the majority of reports on intracranial MDAVFs are confined to case reports and small case series, and thus understanding of MDAVFs is limited. The current review assesses the available literature to date with the aim of reviewing the progress in research on intracranial MDAVFs. Intracranial MDAVFs may be divided into two types: Synchronous and metachronous. While the exact pathogenesis of MDAVFs is unknown, a number of possible mechanisms are considered relevant. The first is that MDAVFs develop following recanalization of a large sinus thrombosis that involves several sinuses. The second possibility is that a pre-existing DAVF may induce sinus thrombosis or venous hypertension, resulting in a new MDAVF. The third is that MDAVFs are caused by increased angiogenic activity, which may induce the development of MDAVFs. Intracranial MDAVFs have a malignant clinical course, and their symptoms generally rapidly progress following onset. It is therefore important to identify intracranial MDAVFs at an early stage. A number of imaging technologies, including computed tomography (CT), magnetic resonance imaging (MRI), digital subtraction angiography (DSA) and single-photon emission computed tomography (SPECT), may be used to detect MDAVFs. Of these, CT and MRI provide information on brain morphology, SPECT provides brain blood flow information, and DSA is the gold standard that may be used to identify angioarchitecture and hemodynamics. MDAVFs require timely and aggressive treatment, which may include endovascular embolization, surgical resection, radiosurgery and conservative treatment, and in some cases, combined treatments are required. Appropriate and aggressive treatment regimens can markedly improve neurological deficits and cognitive function in patients with MDAVFs.