Evaluation of hearing in children with familial Mediterranean fever: A study during attack and attack-free periods

Introduction
Few studies have investigated the hearing in familial Mediterranean fever (FMF), with conflicting results reported. The aim of this study was to compare the cochlear functions of FMF children with healthy controls and to evaluate any differences in the audiological outcomes of FMF patients during attack and attack-free periods.

Material and methods
In this study were recruited 50 FMF children and 31 healthy children as controls. FMF patients that were in an attack period and a control group underwent audiometric evaluation including pure tone audiometry and Distortion Product Otoacoustic Emission (DPOAE) test. The evaluation was repeated in FMF patients in an attack-free period. Additionally, auditory brainstem response (ABR) test was performed during attack and attack-free periods.

Results
Hearing thresholds of FMF patients, compared to the control group, were found to be increased at all frequencies on the left and at 1000, 4000, and 8000 Hz on the right (p < 0.05). This was supported by the DPOAE test, with lower values at all frequencies in FMF children (p < 0.05). In the attack period, compared to the attack-free period, hearing thresholds were found to be increased only at certain frequencies, but this was not supported by the DPOAE test (p > 0.05). No statistically significant difference between attack and attack-free period for ABR test were found (all p > 0.05).

Conclusions
Our results demonstrated cochlear involvement in FMF patients, but no objective acute impairment in hearing in the attack period, which suggests that hearing impairment in FMF is due to chronic autoinflammation process.