[Analysis of correlation between the pneumatization degree of paranasal sinuses and skull base and spontaneous cerebrospinal fluid rhinorrhea].

Objective: To investigate the relationship between the pneumatization degree of paranasal sinuses and skull base and the incidence of spontaneous cerebrospinal fluid rhinorrhea （SCSFR）. Methods: Date of 107 patients with SCSFR were reviewed retrospectively. Using CT scans, investigator evaluated the pneumatization degree of paranasal sinuses and skull base, and compared classifications of various imaging characteristics between SCSFR group（case group） and nasal septum deviation group（control group）, including frontal cells, Onodi cell, lateral recess of sphenoid sinus （LRSS）, pneumatization of anterior clinoid process and pneumatization of posterior clinoid process. Results: One hundred and eight fistulas are found among 107 cases. The most common site of the fistulas is found in ethmoid sinus （38.89%）, followed by olfactory cleft（37.04%）, sphenoid sinus （21.30%） and frontal sinus （2.77%）.The incidence of Onodi cell was significantly different between case and control group（ χ ²=4.755, P <0.05）, and the classification of Onodi cell has a linear effect on the occurrence of SCSFR （ Z =3.345, P <0.05）, which suggests the increasing level of Onodi cell can increase the probability in occurrence of SCSFR. The incidence of type Ⅲ LRSS in the case group is significantly higher than in the control group（ χ ²=18.725, P <0.05）,a linear correlation is found between the classification of LRSS and the incidence of SCSFR （ Z =3.578, P <0.05）.There was no significant difference in the incidence of frontal cells between the two groups（ χ ²=0.672, P >0.05）, nor was there a linear relationship between the classification of frontal cells and the incidence of SCSFR （ Z =0.503, P >0.05）. Pneumatization of anterior clinoid process and posterior clinoid process were no significant difference between case and control （ P >0.05）,nor were there linear relationships between their classifications and SCSFR （ P >0.05）. Conclusion: The most common site of SCSFR is ethmoid sinus, followed by olfactory cleft,the hyperpneumatization of the LRSS and Onodi cell are closely related to its pathogenesis.