Leakage detection on CT myelography for targeted epidural blood patch in spontaneous cerebrospinal fluid leaks: calcified or ossified spinal lesions ventral to the thecal sac

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>The purpose of this study was to describe significant CT myelography findings for determination of the leak site and outcome of targeted epidural blood patch (EBP) in patients with spontaneous CSF leaks.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>During 2005–2013, spontaneous CSF leaks were diagnosed for 12 patients with orthostatic headaches. The patients received targeted EBP on the basis of CT myelography assessments.</jats:p></jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>Computed tomography myelograms revealed ventral extradural collection of contrast medium distributed over multiple spinal levels (average 16 levels). Intraforaminal contrast medium extravasations were observed at multiple spinal levels (average 8.2 levels). For 8 (67%) of 12 patients, spinal lesions were noted around the thecal sac and included calcified discs with osteophytes, an ossified posterior longitudinal ligament, and an ossified yellow ligament; lesions were mostly located ventral to the thecal sac and were in close contact with the dura mater. The levels of these spinal lesions were considered potential leak sites and were targeted for EBP. For the remaining 4 patients who did not have definite spinal lesions around the thecal sac, leak site determination was based primarily on the contrast gradient hypothesis. The authors hypothesized that the concentration of extradural contrast medium would be the greatest and the same as that of intradural contrast medium at the leak site but that it would decrease with increased distance from the leak site according to the contrast gradient.</jats:p> <jats:p>Epidural blood patch was placed at the level of spinal lesions and/or of the greatest and same concentration of contrast medium between the intradural and extradural spaces. For 10 of the 12 patients, the orthostatic headaches decreased significantly within a week of EBP and disappeared within a month. For the remaining 2 patients, headaches persisted and medical treatment was required for several months. For 3 patients, thick chronic subdural hematomas caused severe headaches and/or disturbed consciousness because of the mass effect of the hematomas, which were removed by bur hole drainage surgery. For 1 patient, bur hole drainage before EBP on the day of admission to hospital resulted in subdural tension pneumocephalus. The patient's headache immediately disappeared after EBP, and the hematoma did not recur. The other 2 patients underwent EBP followed by bur hole drainage, which resulted in improvements and disappearance of the hematomas. Over the follow-up period (mean 39 months), no CSF leaks or chronic subdural hematomas had recurred in any patient after EBP; by the final follow-up visit, all patients had returned to their jobs.</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>The most significant finding of this study was that spinal ventral calcified or ossified lesions, which may be associated with a dural tear, were present in approximately 70% of patients. Targeted EBP to these lesions resulted in good outcomes.</jats:p></jats:sec>

Clinical Features of Patients With Spontaneous Intracranial Hypotension Complicated With Bilateral Subdural Fluid Collections

“…Various clinicians subsequently reported the efficacy of epidural blood patch at non‐targeted lumbar levels . Recent studies have demonstrated that targeted EBP at the site of a presumed leak point achieves better outcomes than non‐targeted methods . Thus, based on the existing literature, most of the patients with SIH could be treated with these methods.…”

Cervical Foraminal Epidural Blood Patch for the Targeted Treatment of Refractory Cerebrospinal Fluid Leakage From a Dural Sleeve

“…2 Spondylotic spurs and herniated discs have also been implicated as causative factors. 7 Although EBP provides persistent relief in 61% to 75% of patients with postdural puncture headache, 8 Sencakova et al 9 found that only 36% of subjects with SIH responded to EBP. However, these authors observed another 20% of patients improved after a second EBP and 16% after multiple attempts.…”

Application of time-spatial labeling inversion pulse magnetic resonance imaging in the diagnosis of spontaneous intracranial hypotension due to high-flow cerebrospinal fluid leakage at C1-2

“…The dynamic visualization of CSF outflow using imaging studies may be helpful and may provide evidence of CSF leakage at that particular level. Although the importance of dynamic digital subtraction myelography and CT myelography in identifying the CSF leakage point has been recognized,[91318] they present the major disadvantage of increased radiation exposure. In this context, identifying leakage points with MRI is beneficial in reducing the risk.…”