Bone conducted cervical vestibular evoked myogenic potentials: comparison of tone burst stimulus vs chirp stimulus.

Purpose: Vestibular evoked myogenic potential (VEMP) is a test used to evaluate the function of otolith organs. In healthy individuals, air-conducted (AC) responses are obtained, whereas, in conductive hearing loss, the inability to transmit the signal well enough with AC stimuli has led to the need for bone-conducted (BC) stimuli. This study aimed to compare 500 Hz Chirp and Tone Burst stimuli in terms of latency and amplitude in BC cVEMP.

Methods: This prospective observational case control study included 35 healthy participants (70 ears) between the age of 20-50. Participants underwent VEMP testing with BC 500 Hz Tone Burst stimulus and 500 Hz narrow band Chirp stimulus without changing the position of the bone conducted vibrator. The intensity of the stimuli was 50 dB nHL.

Results: Response rate of 500 Hz TB Stimulus was 51.4% and 95.7% in Chirp stimulus. It was observed that significantly more responses were obtained with Chirp stimulus than TB stimulus (p < 0.001). In terms of p1 latency, n1 latency, both latencies were significantly shorter in Chirp stimulus (p < 0.001). p1n1 amplitude was found significantly larger in Chirp stimulus (p < 0.001).

Conclusion: Compared to 500 Hz TB stimulus, 500 Hz Chirp stimulus results in a higher response rate, larger p1n1 amplitude, and shorter p1 and n1 latency. A higher response rate may provide a more accurate assessment of otolith organs, reducing false negatives due to signal transmission in patients.