Spinal CSF venous fistula: A treatable etiology for CSF leaks in craniospinal hypovolemia

Pachymeningeal enhancement and brain sagging are recognized neuroimaging manifestations of craniospinal hypovolemia (CSH).1 Typically, CSF leaks from a dural defect, pools in the epidural space, and is absorbed into epidural veins. It is subsequently seen as early radiotracer activity on cisternography or as contrast in the renal pelvis on CT myelography. Not infrequently, despite extensive investigations, a dural defect is not identified in patients with CSH.2 Many of these patients undergo repeated single or multilevel blood patches with limited benefit.