Abstract
BACKGROUND AND PURPOSE: Localizing a CSF leak in a patient with spontaneous intracranial hypotension (SIH) is of utmost importance when pursuing a targeted therapy. The study aimed to evaluate the accuracy of dynamic myelography techniques in localizing spinal CSF leaks and report the number of examinations required, stratified by leak type and spinal level. MATERIALS AND METHODS: Consecutive patients with SIH with a spinal longitudinal extradural CSF collection (SLEC) investigated at our department from January 2013 to February 2025 were screened. All included patients underwent a dynamic myelography work-up to localize the level of spinal CSF leak using conventional dynamic myelography (CDM) and/or dynamic CT myelography (DCTM). RESULTS: In total, 198 SLEC-positive patients with SIH (mean age: 50 ± 12 years; 67% women, 133/198) were included. In total, 147 patients had a ventral (74%), 49 patients had lateral (25%), and 2 patients had a primary dorsal (1%) leak. The spinal CSF leak was localized with the first, second, third, or fourth dynamic myelography in 97 (49%), 70 (35%), 16 (8%), and 11 patients (6%), respectively. The median number of myelography examinations (CDM + DCTM) per patient to localize a CSF leak was 2 (interquartile range [IQR] 1-2; range 1-8), 1 (IQR 1-2; range 1-5) for ventral, 2 (IQR 1-2; range 1-6) for lateral, and 6 (IQR 5-7; range 4-8) for dorsal leaks. In total, 160 patients (81%) were referred for microsurgical closure. The dural leak was identified intraoperatively on the indicated vertebral level in 153 patients (96%); in 2 patients (1.3%), spontaneous sealing occurred, and in 5 patients (3%), wrong level surgery occurred. CONCLUSIONS: Dynamic myelography examinations accurately and reliably localize spinal CSF leaks in patients with SIH with SLEC. In about one-half of the patients, the level of the leak can be localized with the first CDM. In case of a repeat dynamic myelography, the technique and patient positioning can be adopted according to the results of the previous examination. Primary dorsal leaks are rare, but because of the low level of suspicion, they pose a diagnostic challenge.