Radiological Markers Associated with Intracranial Hypertension in Spontaneous Middle Cranial Fossa Cerebrospinal Fluid Leaks: A Retrospective Comparison with Trigeminal Neuralgia Controls

Objectives: To determine whether radiological markers associated with intracranial hypertension are enriched in patients with spontaneous middle cranial fossa (MCF) CSF leaks compared with trigeminal neuralgia (TN) controls and to characterize the clinical, anatomical, and venographic phenotype of the MCF cohort. Design: Retrospective comparative cohort study. Setting: Single institution. Participants: Eighty-four adults with surgically and radiographically documented spontaneous MCF CSF leaks and 43 TN controls with MRI adequate for prespecified-marker evaluation. Outcome measures: The primary outcome was a conventional MRI-marker composite comprising partial/complete empty sella, optic-nerve/perioptic-sheath abnormality, or Meckel cave prominence. Adjusted modified Poisson regression estimated PRs. Overlap weighting and Firth regression were sensitivity analyses. Results: The conventional MRI-marker composite was present in 33/84 MCF patients (39.3%) and 6/43 TN controls (14.0%; P=.004). After adjustment for age, sex, and BMI, its prevalence remained significantly higher in the MCF cohort (adjusted PR, 2.31; 95% CI, 1.01-5.27; P=.047). Partial/complete empty sella demonstrated the strongest individual association (adjusted PR, 3.45; 95% CI, 1.25-9.49; P=.017). A secondary broad comparable composite that additionally included encephalocele was approximately 5.7-fold more prevalent in the MCF cohort (adjusted PR, 5.74; 95% CI, 2.64-12.48; P<.001). Within the MCF cohort, 69/84 patients (82.1%) had at least one component of the original VSS-inclusive composite, and VSS was documented in 26/50 venographically assessed patients. Conclusion: Patients with spontaneous MCF CSF leaks had a higher prevalence of conventional intracranial-hypertension-associated MRI markers than TN controls after adjustment for age, sex, and BMI. The primary composite excluded both encephalocele and VSS.