CSF-Venous Fistula.

PURPOSE OF REVIEW: To provide an update on recent developments in the understanding, diagnosis, and treatment of CSF-venous fistula (CVF). RECENT FINDING: CVF is a recently recognized cause of spontaneous intracranial hypotension (SIH), an important secondary headache, in which an aberrant connection is formed between the spinal subarachnoid space and an adjacent spinal epidural vein permitting unregulated loss of CSF into the circulatory system. CVFs often occur without a concurrent epidural fluid collection; therefore, CVF should be considered as a potential etiology for patients with SIH symptomatology but without an identifiable CSF leak. Imaging plays a critical role in the detection and localization of CVFs, with a number of imaging techniques and provocative maneuvers described in the literature to facilitate their localization for targeted and definitive treatment. Increasing awareness and improving the localization of CVFs can allow for improved outcomes in the SIH patient population. Future prospective studies are needed to determine the diagnostic performance of currently available imaging techniques as well as their ability to inform workup and guide treatment decisions.

Evaluation of degenerative disease of the lumbar spine: MR/MR myelography versus conventional myelography/post-myelography CT.

BACKGROUND: To compare the use of magnetic resonance (MR)/MR myelography (MRM) with conventional myelography/post-myelography CT (convM) for detailed surgery planning in degenerative lumbar disease. METHODS: Twenty-six patients with suspected complex lumbar degenerative disease underwent MRM in addition to convM as preoperative workup. Surgery was planned based on convM-as usual at our department. Post hoc, surgical planning was repeated planned again-now based on MRM. Furthermore, the MRM-based planning was performed by six independent neurosurgeons (three groups) of different degrees of specialisation. RESULTS: In only 31 % of the patients, post hoc MRM-based planning resulted in the same surgical decision as originally performed, whereas in 69 % (n = 18) a different procedure was indicated. In patients with non-concurring convM- and MRM-based surgical plans, a less extended procedure was the result of MRM in six patients (23 %), a more extended one in five (19 %), and a related to side/level of decompression or nucleotomy different plan in six patients (23 %). In one patient (4 %), the MRM-based planning would have led to a completely different surgery compared to convM. Overall interobserver agreement on the MRM-based planning was substantial. CONCLUSIONS: Detailed planning of operative procedures for complex lumbar degenerative disease is highly dependent on the image modality used.

Spinal Cerebrospinal Fluid Leak Localization with Digital Subtraction Myelography: Tips, Tricks, and Pitfalls.

Cerebrospinal fluid (CSF) leak can cause spontaneous intracranial hypotension (SIH) which can lead to neurologic symptoms, such as orthostatic headache. Over time, imaging techniques for detecting and localizing CSF leaks have improved. These techniques include computed tomography (CT) myelography, dynamic CT myelography, cone-beam CT, MRI, MR myelography, and digital subtraction myelography (DSM). DSM provides the highest sensitivity for identifying leak sites and has comparable radiation exposure to CT myelography. The introduction of the lateral decubitus DSM has proven invaluable in localizing leaks when other imaging tests have been inconclusive.

Spontaneous Intracranial Hypotension: Clinical Presentation, Diagnosis, and Treatment Strategies.

Spontaneous intracranial hypotension (SIH) typically presents as an acute orthostatic headache during an upright position, secondary to spinal cerebrospinal fluid leaks. New evidence indicates that a lumbar puncture may not be essential for diagnosing every patient with SIH. Spinal neuroimaging protocols used for diagnosing and localizing spinal cerebrospinal fluid leaks include brain/spinal MRI, computed tomography myelography, digital subtraction myelography, and radionuclide cisternography. Complications of SIH include subdural hematoma, cerebral venous thrombosis, and superficial siderosis. Treatment options encompass conservative management, epidural blood patches, and surgical interventions. The early application of epidural blood patches in all patients with SIH is suggested.

Comparing 2-dimensional versus 3-dimensional MR myelography for cerebrospinal fluid leak detection.

Purpose: We compared cerebrospinal fluid (CSF) leak conspicuity and image quality as visualized using 3D versus 2D magnetic resonance (MR) myelography in patients with spinal CSF leaks. Methods: Eighteen patients underwent spinal MR imaging at 3 Tesla. Three board-certified radiologists independently evaluated CSF leak conspicuity and image quality on a 4-point scale; the latter assessed by scoring fat suppression, venous visualization, and severity of CSF flow artifacts. Additionally, the evaluators ranked the overall performances of 2D versus 3D MR myelography upon completing side-by-side comparisons of CSF leak conspicuity. Inter-reader agreement was determined using the Gwet's AC1. Results: The quality of 3D MR myelography images was significantly better than that of 2D MR myelography with respect to CSF leak conspicuity (mean scores: 3.3 vs. 1.9, p < 0.0001) and severity of CSF flow artifacts on the axial view (mean scores: 1.0 vs. 2.5, p = 0.0001). Inter-reader agreement was moderate to almost perfect for 2D MR myelography (AC1 = 0.55-1.00), and almost perfect for 3D MR myelography (AC1 = 0.85-1.00). Moreover, 3D MR myelography was judged to be superior to 2D acquisition in 78 %, 83 %, and 83 % of the samples per readers 1, 2 and 3, respectively; the inter-reader agreement was almost perfect (AC1: reader 1 vs. 2; 0.98, reader 2 vs. 3; 0.96, reader 3 vs. 1; 0.98). Conclusion: CSF leaks are more conspicuous when using 3D MR myelography than when using its 2D counterpart; therefore, the former is more reliable for identifying such leaks.

Diagnostic Yield of Intrathecal Gadolinium MR Myelography for CSF Leak Localization.

PURPOSE: Intrathecal gadolinium magnetic resonance (MR) myelography can be used to localize various types of spinal cerebrospinal fluid (CSF) leaks; however, its diagnostic yield is not well known. We sought to determine the diagnostic yield of MR myelography in patients with spontaneous intracranial hypotension. METHODS: A retrospective review was performed on all patients who had undergone intrathecal gadolinium MR myelography at our institution from 2002 to 2020 for suspected spinal CSF leak. The MR myelography images were reviewed for the presence or absence of a spinal CSF leak site. Images were also evaluated for the presence an extradural fluid collection. RESULTS: A total of 97 patients were included in the final cohort. The average age was 52.6 years; 67.0% were female, 4 patients underwent 2 examinations each, yielding a total of 101 MR myelograms. The source of a spinal CSF leak was localized in 14 patients. The diagnostic yield for CSF leak localization on intrathecal gadolinium MR myelography was 14/101 (13.9%) per GdM examination and 14/97 (14.4%) per patient. Among the subset of patients without extradural fluid collections, the yield was 15.7% per examination. All detected leaks were either CSF-venous fistulas or distal nerve root sleeve tears. CONCLUSION: Intrathecal gadolinium MR myelography is capable of localizing CSF-venous fistulas and distal nerve root sleeve tears; however, our data show that it has a limited diagnostic yield. We suggest that other modalities may be a better first step before attempting intrathecal gadolinium MR myelography.

Cerebrospinal fluid hypovolemia syndrome mimicking ocular myasthenia gravis: A case report.

Purpose: Cerebrospinal fluid hypovolemia syndrome (CHS) is a rare clinical entity that can be caused by spontaneous cerebrospinal fluid (CSF) leakage. The aim of this study is to report a rare case of CHS after a traffic accident in a patient who presented with diplopia and ptosis with fluctuation and was initially diagnosed with ocular myasthenia gravis. Observeations: A 29-year-old man exhibited fluctuating left ptosis and diplopia after a traffic accident. Although he was suspected of having myasthenia gravis and was treated using oral pyridostigmine bromide, his symptoms did not improve. He also had orthostatic headaches and malaise after the accident. His symptoms were suspected to be associated with traumatic cerebrospinal fluid hypovolemia. After 1000-mL fluid replacement, his diplopia and ptosis improved, and orbital T2-weghted MRI detected a high-signal zone around the optic nerve. We diagnosed him with oculomotor nerve paresis associated with cerebrospinal fluid hypovolemia. The symptoms, including ptosis, diplopia, orthostatic headaches, and malaise, disappeared after epidural blood patch therapy. Conclusions and Importance: When treating patients with fluctuating ocular symptoms, such as diplopia and ptosis, who have a history of trauma and orthostatic headaches, the possibility of CHS should be considered in the differential diagnosis.

Intravenous enhanced 3D FLAIR imaging to identify CSF leaks in spontaneous intracranial hypotension: Comparison with MR myelography.

PURPOSE: To evaluate the clinical utility of intravenous gadolinium-enhanced heavily T2-weighted 3D fluid-attenuated inversion recovery (HT2-FLAIR) imaging for identifying spinal cerebrospinal fluid (CSF) leaks in patients with spontaneous intracranial hypotension (SIH). METHODS: Patients with SIH underwent MR myelography and post-contrast HT2-FLAIR imaging after an intravenous gadolinium injection. Two types of CSF leaks (epidural fluid collection and CSF leaks around the nerve root sleeve) at each vertebral level were compared between the 2 sequences. The total numbers of CSF leaks and vertebral levels involved were recorded for the whole spine. The sequence that was superior for the overall visualization of epidural and paraspinal fluid collection was then selected. RESULTS: Nine patients with SIH were included in the present study. HT2-FLAIR imaging was equivalent or superior to MR myelography at each level for detecting the 2 types of CSF leaks. In the 2 types of CSF leaks, the total numbers of CSF leaks and levels involved were higher on HT2-FLAIR images than on MR myelography, while no significant difference was observed for CSF leaks around the nerve root sleeve. In all 9 patients, HT2-FLAIR imaging was superior to MR myelography for the overall visualization of epidural and paraspinal fluid collection. CONCLUSION: Intravenous gadolinium-enhanced HT2-FLAIR imaging was superior to MR myelography for the visualization of CSF leaks in patients with SIH. This method can be useful for identifying spinal CSF leaks.

Cerebrospinal fluid hypovolemia syndrome after a traffic accident with abnormal eye movements: A case report.

PURPOSE: To describe a rare case of cerebrospinal fluid hypovolemia syndrome after a traffic accident with abnormal eye movements. OBSERVATIONS: A 19-year-old man was referred to our clinic after being hit by a car five months ago while riding a bicycle. After the accident, he sometimes noticed oscillopsia, and had postural headaches and reading difficulties. His eye movement recording revealed square wave jerks during fixation and decreased pursuit gain during horizontal smooth pursuit. MR myelography detected cerebrospinal fluid leakage and the patient was diagnosed with cerebrospinal fluid hypovolemia. After undergoing epidural blood patch therapy, the leakage disappeared, and his postural headaches improved immediately. Square wave jerks and decreased pursuit gain improved, and his oscillopsia and reading difficulty also improved after therapy. CONCLUSIONS AND IMPORTANCE: A patient with cerebrospinal fluid hypovolemia presented with square wave jerks and decreased pursuit gain. Epidural blood patch therapy was effective for the symptoms. When treating patients with oscillopsia and postural headaches, we should consider the possibility of cerebrospinal fluid hypovolemia syndrome in the differential diagnosis.

Intrathecal preservative-free normal saline challenge magnetic resonance myelography for the identification of cerebrospinal fluid leaks in spontaneous intracranial hypotension.

OBJECT: A CSF leak can be difficult to locate in patients who present with spontaneous intracranial hypotension (SIH). The purpose of this case series was to describe the authors' experience with intrathecal preservative-free normal saline challenge coupled with contrast-enhanced MR myelography (CEMRM), which was used to provoke and detect a CSF leakage site in patients with SIH. METHODS: The authors performed a retrospective review of the records of patients who underwent preservative-free normal saline challenge followed by intrathecal gadolinium (Gd) contrast infusion and MR myelography from 2010 to 2012. RESULTS: The records survey identified 5 patients who underwent 6 procedures. Intrathecal preservative-free normal saline challenge followed by CEMRM identified a CSF leak during 5 of the 6 procedures. Previous CT myelograms were available from 4 patients, which did not reveal a leakage site. A CT myelogram of 1 patient showed a single leak, but the authors' saline challenge-CEMRM technique identified multiple additional leakage sites. Three patients exhibited transient postprocedural symptoms related to the saline infusion, but no long-term or permanent adverse effects related to the procedure were observed. CONCLUSIONS: Instillation of preservative-free normal saline into the thecal sac followed by intrathecal Gd infusion is a safe technique that may increase the detection of a CSF leak on MR myelography images in patients with SIH.

Comparative study of lumbar magnetic resonance imaging and myelography in young soldiers with herniated lumbar disc.

OBJECTIVE: This study was undertaken to compare the diagnostic performances of magnetic resonance imaging (MRI), MR myelography (MRM) and myelography in young soldiers with a herniated lumbar disc (HLD). METHODS: Sixty-five male soldiers with HLD comprised the study cohort. A visual analogue scale for low back pain (VAS-LBP), VAS for leg radiating pain (VAS-LP), and Oswestry disability index (ODI) were applied. Lumbar MR, MRM, and myelographic findings were checked and evaluated by four independent radiologists, respectively. Each radiologist was asked to score (1 to 5) the degree of disc protrusion and nerve root compression using modified grading systems devised by the North American Spine Society and Pfirrmann and the physical examination rules for conscription in the Republic of Korea. Correlated coefficients between clinical and radiological factors were calculated. Interpretational reproducibility between MRI and myelography by four bases were calculated and compared. RESULTS: Mean patient age was 20.5 ± 1.1. Mean VAS-LBP and VAS-LP were 6.7 ± 1.6 and 7.4 ± 1.7, respectively. Mean ODI was 48.0 ± 16.2%. Mean MRI, MRM, and myelography scores were 3.3 ± 0.9, 3.5 ± 1.0, and 3.9 ± 1.1, respectively. All scores of diagnostic performances were significantly correlated (p < 0.05). However, none of these scores reflected the severity of patients' symptoms. There was no statistical difference of interpretational reproducibility between MRI and myelography. CONCLUSION: Although MRI and myelography are based on different principles, they produce similar interpretational reproducibility in young soldiers with a HLD. However, these modalities do not reflect the severity of symptoms.

Morphologic Changes of L5 Root at Coronal Source Images of MR Myelography in Cases of Foraminal or Extraforaminal Compression.

OBJECTIVE: TWO FINDINGS EASILY FOUND AT CORONAL SOURCE IMAGES OF MR MYELOGRAPHY (MRM) WERE EVALUATED : dorsal root ganglion (DRG) swelling and running course abnormality (RCA) of L5 exiting root at foramen or extraforamen. We tried to find the sensitivity of each finding when root was compressed. METHODS: From 2004 July to 2006, one hundred and ten patients underwent one side paraspinal decompression for their L5 root foraminal or extraforaminal compression at L5-S1 level. All kinds of conservative treatments failed to improve leg symptom for several months. Before surgery, MRI, CT and MRM were done. Retrospective radiologic analysis for their preoperative MRM coronal source images was done to specify root compression sites and L5 root morphologic changes. RESULTS: DRG swelling was found in 66 (60%) of 110 patients. DRG swelling has statistically valuable meaning in foraminal root compression (chi-square test, p < 0.0001). Seventy-two (66%) in 110 patients showed abnormal alteration of running course. Abnormal running course has statistically valuable meaning in foraminal or extraforaminal root compression (chi-square test, p < 0.0001). CONCLUSION: Three-dimensional MRM provides precise thin sliced coronal images which are most close to real operative views. DRG swelling and running course abnormality of L5 exiting root are two useful findings in diagnosing L5 root compression at L5-S1 foramen or extraforamen. MRM is thought to provide additional diagnostic accuracy expecially in L5-S1 foraminal and extraforaminal area.