Diagnosing idiopathic intracranial hypertension in patients with spontaneous cerebrospinal fluid rhinorrhoea: the growing significance of neuroradiological criteria.

Abstract

Purpose: To prospectively identify the prevalence of idiopathic intracranial hypertension (IIH) in a cohort of patients with spontaneous cerebrospinal fluid rhinorrhoea (SCSFR) using the previously published clinico-radiological Vellore criteria for IIH.

Methods: Patients diagnosed with SCSFR over a 23-month period were prospectively evaluated using clinical methods and neuroimaging. Clinical evaluation included ophthalmological examination by fundoscopy and optical coherence tomography. Optic nerve sheath diameter (ONSD) measurement was performed using ultrasound scanning. Neuroimaging was performed by the acquisition of heavily T2 weighted MR images of the brain and skull base. Patients were categorised into definite, probable and no IIH using the Vellore diagnostic criteria.

Results: Fifty-five patients (45 (81.8%) being women) with a mean age of 43.4+/-9.3 years were recruited to the study. Besides CSF rhinorrhoea, headache was the commonest symptom (70.9%). Eleven (20%) patients had papilledema. Empty sella (Yuh et al. grade IV and V) (74.5%) was the commonest MR finding suggestive of IIH. The overall prevalence of IIH in patients with SCSFR was 85.8%. Of these, 35 (63.7%) had definite IIH, 12 (21.8%) had probable IIH and 8 (14.6%) had no IIH. Older patients were more likely to have definite IIH (mean age, 45.5 ± 9 years) than probable IIH (mean age, 39 ± 8.5 years) with an odds ratio of 1.095 (95% CI, 1.001-1.199)(p = 0.048). Among patients with definite IIH, Meckel's cave enlargement (49.1%) was more frequently seen than posterior globe flattening (21.8%).

Conclusion: Patients with SCSFR have a high likelihood of having IIH. We recommend the use of Vellore criteria, which is highly reliant on MR findings, to avoid under-diagnosis of IIH in these patients.