The Incidence of Radiographic or Clinical Markers of Idiopathic Intracranial Hypertension in Those with Spontaneous CSF Leak

Introduction: Spontaneous cerebrospinal fluid (CSF) leaks involve CSF egress following an opening in the dura without a discernable cause. Some theories suggest that increased intracranial pressure as seen in idiopathic intracranial hypertension (IIH) can lead to spontaneous CSF leaks. The current diagnostic criteria for IIH include papilledema and an elevated lumbar puncture (LP) pressure. In those that have CSF leaks, this may lead to underdiagnosis of IIH.

Objective: To evaluate the incidence of radiographic and clinic markers classically associated with IIH in those with spontaneous CSF leaks.

Methods: A review of the electronic medical record was conducted for patients admitted for spontaneous CSF leak between January 2012 and December 2022. Demographic (age, BMI), radiologic (optic nerve sheath diameter, presence and degree of empty sella, Meckel’s cave size by length, width, diameter, and total volume), and clinical (ophthalmic exam findings, presenting symptoms, IIH diagnostic status) data were collected for these patients.

Results: Thirty patients (mean age: 51.7) were included in the analysis. Of the 14 patients who had recorded pre- or intra-operative LP pressures, only five met the criteria for diagnosis of IIH (>25 cm H₂O). Only one patient of the 30 presented with papilledema. Out of the 24 patients who had Meckel’s cave measurements, 22 (91.7%) had dilated volume (>540 mm³). A total of 18 patients (72.0%) out of 25 had dilated optic nerve sheath (>5.17 mm). 15 patients (57.6%) out of 26 had an empty or partially empty sella on MRI.

Conclusion: There is an increased incidence of radiographic markers of IIH in those with spontaneous CSF leaks. Although the presence of papilledema and elevated LP pressures are classically associated with IIH, evidence of dilated Meckel’s cave volume, dilated optic nerve sheath diameter, and the presence of an empty sella may help assist with the diagnosis of IIH, especially in patients who are susceptible to spontaneous CSF leaks.

Publication History

Article published online:
05 February 2024