Vestibular system in infants after systemic therapy with amikacin.

OBJECTIVE

The ototoxic action of systemic therapy with aminoglycosides, used in vital infections in infants, is well recognized. Nevertheless, the routine examination of the infants' inner ear does not include vestibular tests. The purpose of the study was to evaluate vestibular function in a group of infants before and after administration of aminoglycosides, using caloric tests and vestibular evoked myogenic potentials (VEMPs).

DESIGN

Randomized clinical study.

SETTING

Tertiary referral centre.

METHODS

VEMPs and auditory brainstem responses were recorded and caloric stimulation was performed in 68 infants aged 2.5 to 3.5 months: 40 healthy controls and 28 infants after therapy with amikacin. Antibiotic therapy was administered for a respiratory infection in 18 infants and for sepsis in 10 infants. The tests were performed on the day of admission to hospital and on the day of discharge.

MAIN OUTCOME MEASURE: The vestibular organ in infants after systemic therapy with amikacin was damaged more frequently than the cochlea.

RESULTS

On the day of discharge, no reaction to caloric stimulation was elicited in six patients and no VEMPs were recorded in four subjects. Hearing thresholds were normal in all of the individuals during both examinations. The caloric test was a more sensitive indication of the ototoxic impact of amikacin on the vestibular receptors, followed by VEMPs.

CONCLUSIONS

Simultaneous impact of amikacin on the receptor cells of the vestibular organ causes damage to both the semicircular canal and otolith organ receptors. The function of the former is more frequently impaired. The vestibular tests should be performed in infants after treatment with aminoglycosides.