Multiple Spinal CSF Leaks in Spontaneous Intracranial Hypotension. Do They Exist?

Objective:To determine the frequency of multiple spinal CSF leaks in a recent group of patients with spontaneous intracranial hypotension (SIH) who were investigated with digital subtraction myelography (DSM).Methods:This observational study was conducted using data from a prospectively maintained data base of patients who meet the International Classification of Headache Disorders (ICHD)-III criteria for SIH. The patient population consisted of a consecutive group of 745 patients with SIH who underwent DSM between March 2009 and February 2020. Based on the results of DSM, participants were classified according to type and number of spinal CSF leaks.Results:Among 398 patients with SIH and extradural CSF on spinal imaging, multiplicity of CSF leaks was observed in none of 291 patients with type 1a ventral leaks and in four (6.2%) of 65 patients with type 1b (postero-) lateral leaks. Among 97 patients with SIH from spinal CSF-venous fistulas (type 3 leaks) who did not have extradural CSF on spinal imaging, nine patients (9.3%) had multiple fistulas (p<0.0001 for comparison between groups). Type 3 and type 1a or 1b CSF leaks coexisted in an additional five patients.Conclusions:Among patients with SIH, multiplicity of CSF leaks was observed radiographically in none of the patients with ventral leaks, in 6% of patients with lateral leaks, and in 9% of patients with CSF-venous fistulas. These results suggest that patients with SIH can be reassured that the occurrence of multiple CSF leaks is negligible to uncommon at most, depending on type of CSF leak.

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

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.

Rapid Cognitive Decline Secondary to CSF Venous Fistula With Postoperative Rebound Intracranial Hypertension and a Hyperintense Paraspinal Vein Sign Seen Retrospectively

ABSTRACT A 56-year-old female with 2 prior Chiari decompressions presented with rapidly progressive cognitive decline. Brain magnetic resonance imaging, computed tomography myelogram, and prone digital subtraction myelography revealed signs of brain sag and left T9 perineural cysts but no cerebrospinal fluid leaks. Symptoms improved after multilevel blood patches but recurred. Lateral decubitus digital subtraction myelography revealed a spinal cerebrospinal fluid venous fistula (SCVF), which resolved after neurosurgeons ligated the nerve root. Rebound headaches with papilledema occurred on postoperative day 9 and then resolved 2 months after acetazolamide was started. A hyperintense paraspinal vein was seen retrospectively on T2-weighted magnetic resonance imaging with Dixon fat suppression sequencing. This case is unique in the acuity of cognitive decline secondary to SCVF. Acetazolamide at the time of treatment may potentially be used as prophylaxis for rebound intracranial hypertension. The hyperintense paraspinal vein may have utility in future diagnosis of SCVF.

Lateral decubitus digital subtraction myelography to identify spinal CSF–venous fistulas in spontaneous intracranial hypotension

OBJECTIVESpontaneous spinal CSF–venous fistulas are a distinct type of spinal CSF leak recently described in patients with spontaneous intracranial hypotension (SIH). Using digital subtraction myelography (DSM) with the patient in the prone position, the authors have been able to demonstrate such fistulas in about one-fifth of patients with SIH in whom conventional spinal imaging (MRI or CT myelography) showed no evidence for a CSF leak (i.e., the presence of extradural CSF). The authors compared findings of DSM with patients in the lateral decubitus position versus the prone position and now report a significantly increased yield of identifying spinal CSF–venous fistulas with this modification of their imaging protocol.METHODSThe population consisted of 23 patients with SIH who underwent DSM in the lateral decubitus position and 26 patients with SIH who underwent DSM in the prone position. None of the patients had evidence of a CSF leak on conventional spinal imaging.RESULTSA CSF–venous fistula was demonstrated in 17 (74%) of the 23 patients who underwent DSM in the lateral decubitus position compared to 4 (15%) of the 26 patients who underwent DSM in the prone position (p < 0.0001). The mean age of these 16 women and 5 men was 52.5 years (range 36–66 years).CONCLUSIONSAmong SIH patients in whom conventional spinal imaging showed no evidence of a CSF leak, DSM in the lateral decubitus position demonstrated a CSF–venous fistula in about three-fourths of patients compared to only 15% of patients when the DSM was performed in the prone position, an approximately five-fold increase in the detection rate. Spinal CSF–venous fistulas are not rare among patients with SIH.

False localizing signs of spinal CSF–venous fistulas in spontaneous intracranial hypotension: report of 2 cases

A spinal CSF–venous fistula is one of three specific types of spinal CSF leak that can be seen in patients with spontaneous intracranial hypotension (SIH). They are best demonstrated on specialized imaging, such as digital subtraction myelography (DSM) or dynamic myelography, but often they are diagnosed on the basis of increased contrast density in the draining veins (the so-called hyperdense paraspinal vein sign) on early postmyelography CT scans. The authors report on 2 patients who underwent directed treatment (surgery in one patient and glue injection in the other) based on the hyperdense paraspinal vein sign, in whom the actual site of the fistula did not correspond to the level or laterality of the hyperdense paraspinal vein sign. The authors suggest consideration of DSM or dynamic myelography prior to undertaking treatment directed at these fistulas.

Digital subtraction myelography in the investigation of post–dural puncture headache in 27 patients: technical note

OBJECTIVEPost–dural puncture headaches are common, and the treatment of such headaches can be complex when they become chronic. Among patients with spontaneous spinal CSF leaks, digital subtraction myelography (DSM) can localize the exact site of the leak when an extradural CSF collection is present, and it can also demonstrate CSF-venous fistulas in those without an extradural CSF collection. The authors now report on the use of DSM in the management of patients with chronic post–dural puncture headaches.METHODSThe patient population consisted of a consecutive group of 27 patients with recalcitrant post–dural puncture headache that had lasted from 2 to 150 months (mean 26 months).RESULTSThe mean age of the 17 women and 10 men was 39.1 years (range 18–77 years). An extensive extradural CSF collection was present in 5 of the 27 patients, and DSM was able to localize the exact site of the dural defect in all 5 patients. Among the 22 patients who did not have an extradural CSF collection, DSM showed a CSF-venous fistula in 1 patient (5%). Three other patients had a small pseudomeningocele at the level of the dural puncture. Percutaneous glue injection or microsurgical repair resulted in resolution of symptoms in 8 of the 9 patients in whom an abnormality had been identified on imaging.CONCLUSIONSDigital subtraction myelography is able to precisely localize the dural puncture site in patients with a post–dural puncture headache and an extensive extradural CSF collection, and it may rarely detect a CSF-venous fistula in such patients without an extradural CSF collection.