The importance of repeat digital subtraction myelography in the diagnosis of cryptogenic CSF-venous fistula causing spontaneous intracranial hypotension

Abstract

Spontaneous intracranial hypotension (SIH) is a rare disorder that occurs secondary to acquired cerebrospinal fluid (CSF) leaks in the spine. Treatment involves either an epidural blood patch or surgical ligation. Essential to the selecting the optimal management strategy is classifying the type of leak and accurate localization of its level. Hitherto, this has been achieved using conventional imaging methods such as static CT or MR myelography which are adequate for the demonstration of only high flow leaks. Digital subtraction myelography (DSM) is a novel technique which provides superior temporal and spatial resolution in the localization of more challenging slow flow leaks. However, DSM may also be initially non-diagnostic. We report a case of SIH in which repeat DSM revealed a type 3 CSF-venous fistula and demonstrate a possible mechanism of transient CSF leak block resulting in the initial false negative findings based on morphological changes in the culprit nerve sheath diverticulum-pseudomeningocoele complex. The patient underwent successful surgical ligation with clinicoradiological resolution of SIH.

Headache response after CT‐guided fibrin glue occlusion of CSF‐venous fistulas

“…19 CVFs may be found at a spinal level with a functioning nerve root, precluding ligation of the nerve root. 15 CVFs can occasionally be subtle or equivocal on decubitus digital subtraction or CTM, 20 and one could be hard pressed to perform surgery on an equivocal finding. The invasive technique, cost, general anesthesia requirement, and patient recovery time are additional factors.…”

Imaging, Clinical, and Demographic Differences in Patients With Type III Spinal Cerebrospinal Fluid Leak (Cerebrospinal Venous Fistulas) Compared With Patients With Types I and II Spinal Cerebrospinal Fluid Leak

“…[1][2][3] Type III spinal CSF leaks were first described in 2014 and are an increasingly recognized cause of spontaneous intracranial hypotension. [4][5][6][7][8][9][10][11][12][13][14] Because these type III leaks are considered to be slower in nature, they do not necessarily result in epidural fluid collections and can be more difficult to detect compared with types I and II CSF leaks. 15 Much has been previously described in the literature related to use of dynamic myelography, computed tomography myelography (CTM), and digital subtraction myelography to detect types I to III spinal CSF leaks.…”

“…Types I and II leaks are most common, with type III leaks being less common and underrecognized 1–3 . Type III spinal CSF leaks were first described in 2014 and are an increasingly recognized cause of spontaneous intracranial hypotension 4–14 . Because these type III leaks are considered to be slower in nature, they do not necessarily result in epidural fluid collections and can be more difficult to detect compared with types I and II CSF leaks 15 …”