Comparison of tone burst and chirp stimuli at different frequencies of cervical vestibular evoked myogenic potentials in healthy individuals

This study was aimed to determine cVEMP responses obtained with different frequencies of tone burst and chirp stimulis in healthy individuals and to compare these findings. This study was approved by Dışkapı Yildirim Beyazit Training and Research Hospital Clinical Research Ethics Committee (approval date:22.03.2016; approval number: 27/04). This study was conducted with a total of 65 volunteers aged 19-65 years. The sudy included individuals who don't have any otologic, neurotologic and vestibular complaints, with normal external ear canal and tympanic membrane, audiologically electroacoustic immitansmeter levels of ± 50 daPA and type A tympanogram, and pure tone thresholds of 15 dB or better at 125-8000 Hz. It was compared to VEMP's first positive (P1) and subsequent wave of negative (N1) latencies and P1-N1 amplitude between these two wave peaks and VEMP asymmetry rate (VAR). For 500 Hz Tone Burst stimulus, The average of P1 latencies were 12.89 ± 0.81 (ms) and the average of N1 latencies were 21.13 ± 1.65 (ms) and the value of the P1-N1 amplitude was 104.99 ± 36.85 (µV). For 500 Hz Frequency-specific chirp stimulus, P1 latencies were 7.79 ± 0.86 (ms), the average of N1 latency was 16.16 ± 1.67 (ms), the P1-N1 amplitude value was 129.32 ± 41.25 (µV). For 1000 Hz for Tone burst stimuli; P1 latencies was 11.72 ± 0.85 (ms), the average of N1 latency was 19.54 ± 1.62 (ms) the P1-N1 amplitude value was 88.39 ± 29.65 (µV). For 1000 Hz frequency-specific chirp stimulus; P1 latencies was 8.7 ± 0.88 (ms), the average of N1 latency was 16.7 ± 1.75 (ms), the P1-N1 amplitude value was 110.07 ± 35.77 (µV). Significant differences were found at two different frequencies (500 and 1000 Hz) between chirp stimulus and tone burst stimuli P1 (ms), N1 (ms) and P1-N1 (µV) values. İn our study, at both frequencies earlier latencies, higher amplitudes, morphologically clear waves were obtained with chirp stimulus compared to tone burst stimulus.