Hearing loss in a uraemic patient: indications of involvement of the VIIIth nerve

Cochlear sensitivity in children with chronic kidney disease and end-stage renal disease undergoing hemodialysis

OBJECTIVES

Auditory system abnormalities commonly occur in patients with chronic renal disease and end-stage renal disease undergoing hemodialysis. The aim of this study was to determine the relationship between cochlear sensitivity and hemodialysis in dialytic and non-dialytic chronic kidney disease patients.

METHODS

The study included children aged 6-18 years that were divided into 3 groups: 36 non-dialytic patients with chronic kidney disease, 16 end-stage renal disease patients undergoing hemodialysis, and 30 healthy controls. Blood urea nitrogen, serum cystatin C levels, duration of chronic kidney disease, and the duration of hemodialysis were compared between the chronic kidney disease patients and end-stage renal disease patients undergoing hemodialysis. Hearing health was measured via tympanometry, pure-tone audiometry and distortion product otoacoustic emissions testing.

RESULTS

Distortion product otoacoustic emission amplitudes and signal-to-noise ratios were significantly lower at all frequencies tested in the non-dialytic and dialytic groups than in the control group (p<0.05). Patients with normal hearing had significantly lower distortion product otoacoustic emission amplitudes and signal-to-noise ratios than the healthy controls (p<0.05). The duration of CKD, the cystatin C level, and the blood urea level were not associated with hearing loss. The present findings suggest that there was a significant association between the duration of HD and hearing loss.

CONCLUSION

The present findings show that there was impaired cochlear function in the dialytic and non-dialytic patient groups, regardless of hearing loss, as compared to the control group. Patients with chronic renal disease-both dialytic and non-dialytic-should be monitored to prevent any further deterioration by avoiding potential ototoxic agents, even if their hearing thresholds are within normal limits.

Cochlear function of guinea pigs with experimental chronic renal failure

This study aimed to evaluate electrophysiologically the cochlear function of guinea pigs that underwent a five-sixths nephrectomy and, additionally, to explore the synergistic action between chronic renal failure (CRF) and noise. Cochlear potentials were recorded at 1, 2, and 3 months postoperatively. Slight changes in compound action potential and cochlear microphonics were seen at 1 month postoperative, while moderate and profound changes were seen at 2 and 3 months. Endocochlear potential showed no significant reduction. The results indicate that CRF may be an etiologic factor for cochlear dysfunction and that the hair cells seem likely to be a main site of the lesion. One-month-postoperative animals were exposed to a broadband noise. In contrast to control animals, the test animals demonstrated no recovery from the decrease in compound action potential and cochlear microphonics that occurred immediately after noise exposure. This suggests a synergistic interaction between CRF and noise.

Audiological findings in elderly patients with chronic renal failure

The audiological results of 46 patients (m/f 27/19, mean age; 57.4 +/- 11.1) with chronic renal failure (CRF) undergoing dialysis were compared with those of an age- and gender-matched control group (n = 25). Mean pure tone average from 0.5 to 8 kHz was about 15 dB higher in CRF patients than in control subjects. The ABR parameters of the test group were then contrasted with those recorded in a second control group (n = 47, m/f 26/21, mean age: 56.1 +/- 11.4) matched by age, gender and degree of hearing loss (HL). After assessing the normality of the groups by the usual criteria, using the data of a sample of normal young adults, the ABR were found to be abnormal in 23.9% of the controls and in the 39.13% of the CRF patients. Wave V, I-III, III-V and I-V delays were significantly shorter in the females of the control group; in the CRF group, only the V and the I-V delays were shorter in females. The only age-dependent effect was found in the CRF sample, in which older patients had significantly longer I-III IPLD. The degree of HL influenced the latency of the waves in both groups but only the I-V IPLD was longer in CRF patients with pronounced high tone loss. The most distinguishing feature between the effects of CRF plus ageing and those of normal ageing was the lengthening of the I-III IPLD in the test group. This finding is likely to reflect a subclinical disorder of the VIII nerve function that is a part of the axonal uremic neuropathy.