The Link between Rheumatoid Arthritis and Hearing Loss

As if dealing with Rheumatoid Arthritis (RA) wasn't enough, researchers agree that a link exists between RA and certain types of hearing loss that can blunt the perception of differing tones or make all noises and voices sound distant. Furthermore, they agree that hearing loss is an articulation of the disease itself--rather than drug toxicity from medications--but they still cannot entirely pinpoint how or where the hearing loss occurs.

Consider a recent study's findings: Looking for physical changes in an RA patient's middle ear and variations in their hearing capacity, the study used 74 patients and 45 controls. Every subject went through the same line of speech tests, acoustic reflex tests and standard and high frequency tone tests. In every case, the RA patients' hearing threshold was higher than the controls' hearing threshold. (All subjects--RA patient and control--had normal pressure in their middle ear.) Worse, the patients who had RA longer exhibited greater hearing loss; for those with RA for one to five years, the hearing loss usually began at 10,000 Hertz (Hz) while those with RA for eleven years and on exhibited hearing loss at all frequencies, low and high. Because the researchers are using the Hertz measurement, what is at question in this study is the tone of the sound, not the perceived volume or intensity of the sound (that would be decibels); 50 to 60 Hz is a low bass tone and +10,000 Hz is a high-pitched shrill--the normal range for a human is 20 Hz to 20,000.

Similar studies have been done before and have found the same trend: RA somehow brings about hearing loss over time. A 2002 study, using 37 RA patients, reported 35% having sensorineural hearing loss, 24% with conductive hearing loss and an approximate 11% with both types of hearing loss. Sensorineural hearing loss occurs when there is a change in how the cochlea functions; the cochlea is the chamber converting sound vibrations into nerve impulses. Conductive hearing loss occurs when there is a physical defect or obstructions affecting the passage of sound into the inner ear's cochlea. For people with RA (and also without) sensorineural hearing loss is the more common form of hearing loss.

Understandably, the studies point to a malfunction in the cochlea as the location of sensorineural hearing loss but don't get very much father than that--not yet at least. Another study argues that the joints within the ear deteriorate just as the joints in the hand or the hip would, altering the ear's hearing mechanics. Similarly, another study indicates a slackening, or "laxity" in the middle ear's tranducer mechanism.

It is worth considering that hearing loss comes in sensorineural and conductive form--sometimes even simultaneously. If anything else, this suggests there is no one source of hearing loss when it comes to RA, but a complex, "multifocal involvement" as one study puts it. But it is especially worth considering that however gloomy the numbers and head scratching may seem, the same technological advances and commitment to improved care that have allowed the researchers to first identify this problematic link will one day allow them to fix it.

Article References
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Ozcan M, Karakus MF, Gunduz OH, Tuncel U, Sahin H. Hearing loss and middle ear involvement in rheumatoid arthritis. Rheumatol Int. 2002 May;22(1):16-9.

Colletti V, Fiorino FG, Bruni L, Biasi D. Middle ear mechanics in subjects with rheumatoid arthritis. Audiology. 1997 May-Jun;36(3):136-46.

Raut VV, Cullen J, Cathers G. Hearing loss in rheumatoid arthritis. J Otolaryngol. 2001 Oct;30(5):289-94.