Intradural venous engorgement of CSF-venous fistula mimics spinal dural arteriovenous fistula on MRI: A novel case report and review of literature.

Engorgement of spinal intradural veins on MRI has classically been associated with spinal dural arteriovenous fistulas (sdAVF). We report a novel case of a patient who presented with worsening cognitive impairment, whose spinal MRI demonstrated marked intradural venous engorgement in the form of serpiginous perimedullary flow voids akin to sdAVF. Further investigation led to a diagnosis of CSF-venous fistula (CVF), a sub-type of spontaneous spinal CSF leaks without an associated extradural fluid collection. This is the first reported case of CVF mimicking sdAVF on MRI. While clinical presentations of CVF and sdAVF are typically distinct, there may be overlap and/or uncertainty in atypical presentations, such as in our patient. As such, the differential for spinal intradural venous engorgement should be expanded to include spontaneous CSF leaks, including CVF.