Audio-vestibular evaluation in patients with essential tremor

The aim of this study was to investigate audio-vestibular function in patients with essential tremor. Twenty-three patients with essential tremor (46 ears) and 21 health control subjects (42 ears) were included in the present study. Patients and comparison subjects were matched for age and gender. All patient and control subjects underwent pure tone audiometric test, tympanogram, transient-evoked otoacoustic emissions and auditory brainstem response. Vestibular system was evaluated by bitermal caloric test. Comparison of variables between the groups was performed. Investigation of the relationship between parameters about ET disease and hearing levels were also studied. Pure tone thresholds significantly differed between patients and controls in 250 and 500 Hz frequencies (p < 0.05). There was no statistically significant difference in 1,000, 2,000, 4,000, and 6,000 Hz frequencies in essential tremor patients in comparison to the control subjects. A correlation between tremor severity and audiometric scores in low frequencies was not found. In addition, statistical analysis did not demonstrate a correlation between audiometric scores and tremor duration. The otoacoustic emission responses were found significantly different in patient and control group. The latencies of waves I, V and I–V inter-peak latencies on the ABR were not different between the groups. Our findings indicated that, abnormalities are due to cochlea rather than the retro cochlear pathology which is responsible for hearing loss associated with essential tremor.