Objective: The aim of this study was to investigate the ear involvement, especially at extended higher frequencies than those previously studied, in patients with ankylosing spondylitis (AS).
Patients and methods: We prospectively evaluated 45 consecutive patients with AS. All patients underwent a complete physical examination of the ear, nose, and throat and an audiologic evaluation that included pure-tone audiometry at conventional and extended high frequencies, the determination of a speech discrimination score and the uncomfortable loudness level, and impedance audiometry. Thirty healthy volunteers were included as controls.
Results: The mean age of the patients was 39.6 +/- 9.1 years (range 19-63 years) and that of the controls was 10.6 +/- 8.1 years (range 1-30 years). There was no statistically significant difference between the two groups with respect to conventional frequency air conduction threshold and bone conduction threshold. There was a statistically significant difference at 14,000-16,000 Hz at extended high frequencies in 32 patients with AS (71.1%) versus 12 controls (40%). At 14,000-16,000 Hz, eight patients demonstrated a sensorineural hearing loss caused by extraspinal involvement. There was a significant difference between the patients with or without extraspinal involvement, and a positive correlation was noted between the duration of disease and the hearing level at 10,000-16,000 Hz.
Conclusion: Sensorineural hearing loss, especially at extended high frequencies, is common in patients with AS and may be an extra-articular feature of that disease. A long duration of disease and extraspinal involvement are important parameters for ear involvement in patients with AS.