Correlation between Pneumatization Variants of Paranasal Sinuses and Skull Base and Spontaneous Cerebrospinal Fluid Rhinorrhea: A Case-Control Study.

Introduction: Spontaneous cerebrospinal fluid rhinorrhea (SCSFR) is the most common type of cerebrospinal fluid leakage and may cause serious cerebral complications. The aim of this research was to investigate the relationship between the degree of pneumatization variants of the paranasal sinus and skull base and the incidence of SCSFR.

Methods: In total, 131 patients with SCSFR were analyzed, and 50 patients suffering from the nasal septal deviation were selected as controls. The pneumatization of the paranasal sinus and skull base was observed by CT scan.

Results: Among the 137 fistulas, 55 (40.15%) were found in the ethmoid sinus. The incidences of Onodi cells (27.27 vs. 8%) and type 3 lateral recess of the sphenoid sinus (LRSS, 70.37 vs. 22%) in the SCSFR subgroups were significantly higher than those in the control group (p < 0.05). Moreover, the occurrence of SCSFR was linearly correlated with the classification of Onodi cells and LRSS (p < 0.05). There was no significant difference in the incidence of frontal cells, anterior clinoid process pneumatization, and posterior clinoid process pneumatization between the SCSFR patients and the controls.

Conclusion: The most common site of SCSFR is the ethmoid sinus. The excessive pneumatization of the Onodi cell and LRSS increases the risk for the occurrence of SCSFR in the ethmoid sinus and sphenoid sinus, respectively. The possible association between the paranasal sinus ontogeny and SCSFR pathophysiology needs further studies.