Can negative HRCT locate ethmoid CSF leaks? A retrospective analysis.

OBJECTIVE: Spontaneous cerebrospinal fluid (CSF) rhinorrhea is a rare condition, and preoperative identification of the defect location can be challenging. This study aims to summarize the clinical characteristics of spontaneous CSF rhinorrhea and analyze the relationship between ethmoid region defects and missed detection on high-resolution computed tomography (HRCT). DATA SOURCES: We included patients diagnosed with spontaneous CSF rhinorrhea via endoscopic surgery from 2016 to 2024 at the First Affiliated Hospital, Sun Yat-sen University. REVIEW METHODS: Retrospective cohort study. Descriptive statistical analysis was conducted to summarize clinical characteristics. The t-test and Fisher's exact test were used for comparison between patients with defects located in the ethmoid region and those without. Multifactorial logistic regression analysis was performed to evaluate the relationship between ethmoid region defects and HRCT missed detection. RESULTS: A total of 49 patients were included in the study, comprising 20 males (40.82%) and 29 females (59.18%). The average BMI was 25.68 kg/m2. Common symptoms included clear rhinorrhea (89.80%) and headache (20.41%). Multifactorial logistic regression revealed that patients with ethmoid region defects had a 0.04 times lower likelihood of HRCT detection (OR 0.06, 95% CI 0.00-0.40) compared to those with defects located elsewhere. CONCLUSION: Ethmoid region is the most common site of spontaneous CSF rhinorrhea. Pre-operative detection of rhinorrhea defects using HRCT, the most commonly used imaging method in clinical practice, is challenging. Endoscope exploration is necessary for patients who had suspicious symptoms.