S pontaneouS intracranial hypotension (SIH) classically presents as a positional headache that is worsened by orthostasis. Additional symptoms may include dizziness, tinnitus, vomiting, altered mental status, and behavioral changes. 10,11,16 Findings on routine brain CT and MRI scans help to confirm a clinical suspicion of SIH.
5These diagnostic imaging findings include pachymeningeal enhancement, a sagging brain, small ventricular size, and engorged venous sinuses. 9 The combination of these clinical and imaging findings makes diagnosing an SIH often straightforward.6 However, locating the causative CSF leak often remains a challenge. Although new therapeutic techniques have improved the rates of successful treatments of SIH patients with an occult leakage site, identifying the exact location of the CSF leak is preferred before deciding on therapy.11,15 The purpose of this case series was to present our experience with intrathecal preservative-free normal saline challenge followed by contrast-enhanced MR myelography (CEMRM), which we used to provoke and detect a CSF leak in patients with SIH.abbreviatioNs CEMRM = contrast-enhanced MR myelography; CTM = CT myelography; Gd = gadolinium; SIH = spontaneous intracranial hypotension. submitted September 5, 2014. accepted December 11, 2014. iNclude wheN citiNg Published online July 3, 2015; DOI: 10.3171/2014.12.JNS142057. disclosure The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper. 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.