Comparisons between heavily T2-weighted MR and CT myelography studies in two patients with spontaneous intracranial hypotension

Heavily T2-Weighted Magnetic Resonance Myelography as a Safe Cerebrospinal Fluid Leakage Detection Modality for Nontraumatic Subdural Hematoma

Objective

Nontraumatic subdural hematoma (SDH) is a common disease, and spinal cerebrospinal fluid (CSF) leakage is a possible etiology of unknown significance, which is commonly investigated by several invasive studies. This study demonstrates that heavily T2-weighted magnetic resonance myelography (HT2W-MRM) is a safe and clinically effective imaging modality for detecting CSF leakage in patients with nontraumatic SDH.

Methods

All patients who underwent HT2W-MRM for nontraumatic SDH workup at our institution were searched and enrolled in this study. Several parameters were measured and analyzed, including patient demographic data, initial modified Rankin Scale (mRS) score upon presentation, SDH bilaterality, hematoma thickness upon presentation, CSF leakage sites, treatment modalities, followup hematoma thickness, and follow-up mRS score.

Results

Forty patients were identified, of which 22 (55.0%) had CSF leakage at various spinal locations. Five patients (12.5%) showed no change in mRS score, whereas the remaining (87.5%) showed decreases in follow-up mRS scores. In terms of the overall hematoma thickness, four patients (10.0%) showed increased thickness, two (5.0%) showed no change, 32 (80.0%) showed decreased thickness, and two (5.0%) did not undergo follow-up imaging for hematoma thickness measurement.

Conclusion

HT2W-MRM is not only safe but also clinically effective as a primary diagnostic imaging modality to investigate CSF leakage in patients with nontraumatic SDH. Moreover, this study suggests that CSF leakage is a common etiology for nontraumatic SDH, which warrants changes in the diagnosis and treatment strategies.

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.

Utility of heavily T2-weighted MR myelography as the first step in CSF leak detection and the planning of epidural blood patches

Heavily T2-weighted MR myelography (HT2W-MRM) is emerging as an alternative approach for detection and follow up of CSF leaks. We aimed to assess epidural blood patch (EBP) treatment outcome when using HT2W-MRM as the primary modality for detecting CSF leak and planning EBP placement in routine clinical practice. Since 2018, patients at our institute suspected of having CSF leak, routinely HT2W-MRM instead of CT myelography to determine presence of the leak and identify the EBP target site. Fifty-nine consecutive patients suspected of having a CSF leak underwent HT2W-MRM. After excluding patients with subdural hematoma and poor image quality, 26 (10 men, 16 women; mean age 44.92 ± 12.6 years) patients were included in this study. Patients received EBP on the basis of HT2W-MRM assessments and clinical assessment. Imaging findings and clinical outcome were evaluated. CSF leak was identified in 21 patients (80.8%, 21/26) based HT2W-MRM. Most cases were graded on a confidence scale as CSF leak definitely (n = 13) or probably (n = 3) present. Successful clinical EBP treatment was achieved in 14 of 17 patients (82.4%) after first targeted EBP, and patient symptoms significantly improved after treatment (numerical rating score 6.4 before EBP, 1.3 after EBP, P < 0.001). HT2W-MRM based EBP are the rational and effective choices for CSF leak treatment in routine clinical practice.

Cerebrospinal fluid leakage and headache after lumbar puncture: a prospective non-invasive imaging study

The spatial distribution and clinical correlation of cerebrospinal fluid leakage after lumbar puncture have not been determined. Adult in-patients receiving diagnostic lumbar punctures were recruited prospectively. Whole-spine heavily T2-weighted magnetic resonance myelography was carried out to characterize post-lumbar puncture spinal cerebrospinal fluid leakages. Maximum rostral migration was defined as the distance between the most rostral spinal segment with cerebrospinal fluid leakage and the level of lumbar puncture. Eighty patients (51 female/29 male, mean age 49.4 ± 13.3 years) completed the study, including 23 (28.8%) with post-dural puncture headache. Overall, 63.6% of periradicular leaks and 46.9% of epidural collections were within three vertebral segments of the level of lumbar puncture (T12-S1). Post-dural puncture headache was associated with more extensive and more rostral distributions of periradicular leaks (length 3.0 ± 2.5 versus 0.9 ± 1.9 segments, P = 0.001; maximum rostral migration 4.3 ± 4.7 versus 0.8 ± 1.7 segments, P = 0.002) and epidural collections (length 5.3 ± 6.1 versus 1.0 ± 2.1 segments, P = 0.003; maximum rostral migration 4.7 ± 6.7 versus 0.9 ± 2.4 segments, P = 0.015). In conclusion, post-dural puncture headache was associated with more extensive and more rostral distributions of periradicular leaks and epidural collections. Further, visualization of periradicular leaks was not restricted to the level of dural defect, although two-thirds remained within the neighbouring segments.