Vestibular-evoked myogenic potential in the prediction of recovery from acute low-tone sensorineural hearing loss.
OBJECTIVE
Click and galvanic stimulations of vestibular-evoked myogenic potential (c-VEMP and g-VEMP) were applied to measure the interaural difference (IAD) of saccular responses in patients with acute low-tone sensorineural hearing loss (ALHL). This study intended to explore the relationship between saccular asymmetry and final hearing recovery. We hypothesize that greater extent of saccular dysfunction may be associated with lesser hearing recovery.


METHODS
Twenty-one patients with unilateral ALHL were prospectively enrolled to receive c-VEMP and g-VEMP tests in a random sequence. The IAD of the saccular responses for each patient was measured using three parameters-the raw and corrected amplitudes of c-VEMP, and corrected c-VEMP to g-VEMP amplitude ratio (C/G ratio). The IAD for each parameter was classified as depressed, normal, or augmented by calculating the difference between the affected and unaffected ears and dividing by its sum for both ears.


RESULTS
After 3 consecutive months of oral medication and follow-up, 19 patients displayed a hearing recovery of >50%; only two had a recovery of <50%. The significant correlation between the IAD of corrected C/G ratios and hearing recovery demonstrated that subjects with depressed responses had a worse hearing outcome (percent recovery: 51% [45-80%], median [minimum-maximum]), compared with those with normal responses, who exhibited the best recovery (87% [56-100%]), whereas patients with augmented response showed an intermediate recovery (67% [54-100%]; p = 0.02, Kruskal-Wallis test). On the contrary, the raw and corrected amplitudes of c-VEMP did not reveal a significantly different hearing recovery among the three groups of saccular responses.


CONCLUSIONS
The extent of saccular dysfunction in ALHL might be better explored by combining the results of c-VEMP and g-VEMP. Outcome analysis indicated that the corrected C/G ratio might be a promising prognostic factor for hearing recovery in ALHL.
Wang
Chi-Te
CT
Department of Otolaryngology, Far Eastern Memorial Hospital, Taipei, Taiwan.
Fang
Kai-Min
KM
Young
Yi-Ho
YH
Cheng
Po-Wen
PW
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold; D004576:Electromyography / Q000379:methods*; D018159:Endolymphatic Hydrops / Q000175:diagnosis / Q000503:physiopathology / Q000534:rehabilitation; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006309:Hearing / Q000502:physiology; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000503:physiopathology / Q000534:rehabilitation; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D020127:Recovery of Function / Q000502:physiology*; D012444:Saccule and Utricle / Q000503:physiopathology*; D055815:Young Adult