Relationship between CT findings and sensorineural hearing loss in chronic otitis media

Objective

To investigate the relationships between the temporal bone CT findings and sensorineural hearing loss in ears with non-cholesteatomatous chronic otitis media (COM).

Methods

Preoperative bone conduction (BC) hearing thresholds of 266 patients (304 ears) with COM were compared with those of 342 normal individuals (440 ears) by audiometry. The incidence of abnormal BC threshold at lower frequencies (250–1000 Hz) and at higher frequencies (2000–4000 Hz) were examined and the differences between control and COM groups were compared by using χ2 test. In the COM group, the cross-sectional area of the mastoid air cells based on the axial CT image (n = 255) were correlated with the results of BC threshold.

Results

The percentage in the COM group exceeds 15% in their 50s at lower frequencies while in their 40s at higher frequencies. The BC thresholds were significantly better in the group with normal mastoid area than in those with smaller mastoid area at each decadal age group. The BC impairment from COM becomes worse as the course of the disease progresses and deteriorated from 40s rapidly, especially at higher frequencies and in the group with smaller mastoid area.

Conclusion

These results recommend that early treatment, including surgery, should be considered as early as possible before BC impairment occurs, especially for COM cases with smaller mastoid area, which may indicate the existence of more severe otitis media since earlier childhood.