Study Design. A retrospective observational study.
Objective. To compare the usefulness of radioisotope cisternography (RIC) and computed tomography myelography (CTM) for the detection of cerebrospinal fluid (CSF) leakage in spontaneous intracranial hypotension (SIH).
Summary of Background Data. CSF leakage sites have been generally identified by RIC in patients with SIH. Although a number of reports have recently indicated the usefulness of CTM, whether RIC or CTM more reliably detects leakage sites has not been decided because the 2 tests have not been directly compared.
Methods. Both RIC and CTM were performed, and the findings were compared in 12 patients with SIH strictly meeting the second edition of the International Classification of Headache Disorders diagnostic criteria.
Results. On RIC, the detection rate of leakage including indirect signs, an early vesicular radioisotope (RI) accumulation and delayed ascent of the RI to the cerebral convexity, was observed in 100%, but that of the direct sign, paraspinal RI accumulation, was in 8 patients (67%). On CTM, the epidural collection of intraspinally administered contrast medium was demonstrated in all patients (100%), and the collection site was located in the cervical and thoracic vertebral regions in most cases. When RIC and CTM findings were collated, paraspinal accumulation in the cervical and thoracic regions on RIC corresponded to the entire or a part of the findings on CTM. In contrast, in 4 of 5 patients with paraspinal accumulation in the lumbosacral region, epidural collection was not noted in this region on CTM.
Conclusion. In patients with SIH, epidural collection on CTM may more accurately demonstrate CSF leakage compared with paraspinal RI accumulation on RIC.