Risk Factors for Skull Base Spontaneous Cerebrospinal Fluid Leak in Patients with Idiopathic Intracranial Hypertension: A Multinational Database Study

Abstract

Objectives

Skull base spontaneous cerebrospinal fluid leaks (sCSF leaks) represent a distinct cohort of patients with idiopathic intracranial hypertension (IIH). Patients with sCSF leaks often have comorbidities that are modifiable risk factors. In this study, we compare demographics and treatment modalities between IIH patients with sCSF leaks (IIHwL) and IIH patients without skull base sCSF leaks (IIHwoL), and characterize the risk of CSF leak development in IIH patients.

Design

Retrospective cohort study.

Setting

Electronic medical record data from the TriNetX Research database.

Participants

Patients > 18 years old with a diagnosis of IIHwL and patients with a diagnosis of IIHwoL.

Main Outcome Measures

Baseline demographic data and comorbidities were compared and sCSF leak risk evaluated. Shunt placement and medication use were compared for 3 years following diagnosis.

Results

A total of 1,277 IIHwL patients and 90,074 IIHwoL patients were analyzed. IIHwL patients had higher rates of comorbid conditions (p < 0.0001), smoking (p < 0.0001), and were more likely to be prescribed acetazolamide (p < 0.0001) or have a ventriculoperitoneal shunt placed (p = 0.0001) compared with IIHwoL patients. Patients with IIH experienced an average cumulative increase in sCSF leak risk from 0.266% at 1 year to 0.6512% at 5 years.

Conclusion

These findings strengthen the association between IIH as a contributor to sCSF leak risk and imply that longer-standing IIH further increases this risk. This is the first study to identify smoking as a potential sCSF leak risk factor and to both describe and quantify the rate of risk increase for sCSF leak in IIH patients.

Keywords

idiopathic intracranial hypertension - sCSF - rhinology - skull base

Note

This study was presented as an oral presentation at the North American Skull Base 2024.

Publication History

Received: 25 November 2025

Accepted: 09 January 2026

Accepted Manuscript online:
05 February 2026

Article published online:
13 February 2026

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