Differences in skull base thickness in patients with spontaneous cerebrospinal fluid leaks.

Background: This study was designed to determine if differences in overall skull base thickness exist in patients with spontaneous cerebrospinal fluid (SCSF) leaks and to compare our institution's 10-year experience with the endoscopic repair of these leaks to the existing literature. A retrospective cohort study was performed in a tertiary rhinologic practice.

Methods: A retrospective study by two blinded independent reviewers compared the skull base thickness on computerized tomography (CT) imaging in our SCSF leak patients to nonleaking controls and patients with traumatic CSF leaks. Surgical outcomes were compared with a pooled analysis of the published literature.

Results: SCSF leaks were seen most commonly in obese, middle-aged women of African American descent. SCSF leak patients were shown to have thinner skull bases in the region of the ethmoid roof, lateral lamella, and anterior face of the sella (p < 0.05) compared with patients with traumatic leaks and nonleaking controls. No racial difference in skull base thickness was observed when patients were matched according to leak type. The success rate of primary endoscopic intervention in our patients was high at 94% and comparable with the published literature.

Conclusion: Differences in skull base thickness exist in SCSF patients, but whether this predisposes to such leaks or is a consequence of the underlying pathophysiology remains unknown. The endoscopic endonasal approach provides a highly effective means of repairing such leaks with success rates comparable with the endoscopic repair of other leak types. Adjuvant measures including weight reduction, lumbar drain, and acetazolamide use may increase success rates and should be considered in their management.