One of many basic conditions ensuring the normal function of the mechanism transmitting acoustic energy through the middle ear is an effectively working chain of acoustic bones having an uninterrupted sequence and correct mobility of the incudomalleolar joint, incudostapedial joint and tympanostapedial junction.

Both the incudomalleolar and incudostapedial joints are synovial articulations with a cartilaginous joint surface and therefore they, like other joints in the body, may be affected by arthritis (2, 4, 5).

Since Copeman (3) in 1963 first described three cases of acute arthritis accompanied by transient hearing loss of a conductive nature called, which he `oto-arthritis´, attention has been focused on conductive hearing impairment as a result of rheumatoid changes in the joints between the acoustic bones in the middle ear (3, 10, 12).

Although Gussen (6) in 1977 in autopsies of persons affected by chronic arthritis reported rheumatoid changes on the surface of joints in the chain of acoustic bones, which impaired the conductive activity of the middle ear, conductive hearing loss associated with acute arthritis has been controversial until now (1, 7).

According to many authors (2, 4, 5) dealing with hearing problems in the course of rheumatoid arthritis in adults, sensory-nervous hearing loss has been observed in 26-47% of cases (1), whereas conductive hearing loss has been infrequently reported, that is, in 4.8-13% of cases these being mainly in adults with chronic arthritis of a few dozen years duration (1).

Juvenile chronic arthritis (JCA) is a chronic, inflammatory, systemic disease of the connective tissue. The main symptom is progressive inflammation manifested by pain, oedema, stiffness and restriction of the mobility of the joints, leading to their deformation and destruction. In consequence, the functional effectiveness of the osteoarticular system is impaired. Chronic arthritis can be accompanied by rheumatoid nodules, pericarditis and/or myocarditis, lesions in the lungs, kidneys and eyes, occurring with various frequencies and indicating the systemic nature of the disease (12). There are considerable discrepancies in the morbidity rate of juvenile chronic arthritis in the literature. It is based mainly on observation of patients treated in general hospitals and children´s hospitals as well as rheumatoid diseases out-patient departments. The morbidity rate in Poland ranges between 0.5-0.1 per 100000 children.

The aim of our study was:

1. Comprehensive audiological evaluation of middle ear activity and hearing acuity in children 4-16 years of age suffering from juvenile chronic arthritis.

2. Correlation of the lesions in the hearing organ with the type, activity and duration of arthritis on the basis of clinical and laboratory examinations, such as complete blood count, Biernacki reaction, presence or lack of reactive factor (RF), the level of C-reactive protein (CRP), and seromucoid and antinuclear antibodies (ANA).

The study included 38 children aged 4-16 years hospitalized in the Provincial St Lewis Specialist Children´s Hospital in Kraków. The control group comprised 30 otologically healthy children of the same age and sex with no history of symptoms compatible with any type of atropathy. Selection of patients for both study and control groups was based on a negative history of chronic or recurrent otitis media, or upper respiratory tract infections for at least two months before examinations, as well as a lack of conductive hearing loss of another aetiology.

Comprehensive audiometric evaluation of the hearing organ was carried out using subjective audiometric tests, such as:

1.Pure tone audiometry,

2.Verbal audiometry,

3.High frequency audiometry (HFA) in the range of 8-20kHz and objective audiometric tests based on registration of,

4. Evoked otoacoustic emissions (EOAEs),

5. Tympanometric tests.

In this report only the results of pure tone audiometry and tympanometry are discussed.

In all children, the initial analysis of results in all children of pure tone audiometry revealed a correct hearing threshold; mean PTA was 6.9dB, whereas in the control group these values were slightly decreased to 5.2dB.

Tympanometry in all children with juvenile chronic arthritis showed a type A tympanogram and correct pressure in the tympanic cavity with its mean value of 52.8daPa, compliance of 0.8ml and gradient of 46% (Tab. 1).

However, comparative analysis of mean values of tympanometry in the study group and control group shows that despite a similar hearing threshold in pure tone audiometry, the mean pressure in the tympanic cavity is considerably higher in the study group than in the control group and amounts to 52.8daPa and 28.4daPa, respectively. Analysis of the mean values of compliance and the gradient shows that in the study group these values are markedly lower than in the control group; the compliance amounts to 0.8ml and 1.3ml, respectively, and the gradients to 46% and 55%, respectively.

The initial analysis of tympanometry gives rise to the conclusion that in children with juvenile chronic arthritis, type A tympanograms with markedly lowered amplitude are observed, indicating decreased compliance of structures conducting acoustic energy.

This may suggest a negative effect of arthritis on the middle ear function. However, these changes are not sufficient to trigger conductive hearing loss, but they can reduce the effectiveness of defensive mechanisms in the middle ear, which in a long disease course may result in damage to the cochlea and receptive hearing impairment, frequently observed in adults.