Vestibular evoked myogenic potential in unilateral vestibular hypofunction

The patients with unilateral chronic vestibular hypofunction detected by caloric test demonstrated at least some sort of altered vestibular evoked myogenic potential (VEMP) in 63.63% of the cases. The VEMP altered side was the same as the unilateral vestibular hypofunction side in 54.54% of the cases and was the opposite side in 24.24%. The VEMP test improved functional vestibular assessment in patients with unilateral caloric hypofunction.

To analyze VEMP in patients with chronic dizziness and unilateral vestibular hypofunction and verify findings according to the side and structures involved.

This was an observational study. In all, 66 subjects were evaluated by VEMP (tone bursts/1000 Hz/100 dBnHL/bandpass filtered 10-1500 Hz/4.3 Hz rate), 33 with unilateral vestibular hypofunction, detected by caloric test and clinical data, and 33 control subjects, matched by gender and age. Amplitude of the p13-n23, asymmetry index of the amplitude, p13 and n23 latencies, p13 and n23 interaural difference and threshold were analyzed. Simple descriptive analysis was carried out using the t test, Shapiro-Wilks test, and Mann-Whitney test, p < 0.05.

VEMP was altered in patients with unilateral vestibular hypofunction in 63.63% of cases. Thirteen of them were ipsilateral to the vestibular hypofunction and three were contralateral to the vestibular hypofunction. In five cases, VEMP were bilaterally altered.