The Impact of Rheumatoid Arthritis on Middle Ear Function

Abstract

Rheumatoid arthritis (RA) is an autoimmune disease that causes inflammation and swelling of the joints. Middle ear joints may be subject to rheumatic involvement similar to other joints in the body. Results from previous studies examining audiological characteristics in individuals with RA have varied with respect to incidence and type of hearing loss, as well as incidence and type of middle ear involvement (increased or decreased stiffness). The purpose of this study was to compare audiometric, immittance, distortion-product otoacoustic emission (DPOAE), and energy reflectance (ER) results between participants with RA and normal control (NC) participants to further examine the effects of RA on middle ear function. Twenty-one participants with RA (38 ears) were matched 1:1 based on age and gender to 21 individuals (38 ears) without RA. The following measures were completed for all participants: pure-tone air- and bone-conduction thresholds, 226-, 678- and 1000-Hz tympanograms, acoustic reflex thresholds, acoustic reflex decay, and middle ear resonant frequency. ER and DPOAEs were measured for a subset of 16 RA (28 ears) and 16 NC (28 ears) matched participants. No significant difference in prevalence of hearing loss was found between groups. Individuals with hearing loss in both groups presented with sensorineural-type hearing loss, which was typically a mild to moderate high-frequency hearing loss. No significant differences were found between groups for air- and bone-conduction thresholds. A significantly greater number of ears from the RA group had thresholds poorer than the 95th percentile for their age range and gender across the audiometric test frequencies. Generally, younger individuals with RA had poorer thresholds at 1000 and 2000 Hz compared to normative data for age and gender. No differences were found between groups for static admittance, the number of notched versus single-peaked 678- and 1000-Hz tympanograms, acoustic reflex thresholds, ER, and DPOAE measurements. The RA group had a significantly lower mean resonant frequency, consistent with an increase in the laxity or an increase in the mass dominance of the middle ear system. These significant findings revealed the importance of considering audiological assessment of individuals with RA.