Bone Conduction Tone Burst Evoked Masseter Vestibular Evoked Myogenic Potentials

Abstract

Introduction: Masseter vestibular evoked myogenic potential (mVEMP) is an inhibitory potential elicited from masseter muscles in healthy subjects in response to electric/acoustic stimuli. There are a few gaps in research done in the area of masseter VEMPs. The mVEMP elicited by bone conduction (BC) stimuli and its reliability are yet to be studied. Aim and objectives: This study aimed to investigate BC-evoked mVEMP while contrasting gender differences and the reliability of the BC mVEMP. Methods: The study included 30 (15 females and 15 males) healthy individuals in the age range of 18 and 30 years without hearing or vestibular impairments. mVEMP testing was performed on each subject utilizing 500 Hz, 750 Hz and 1000 Hz tone-burst stimuli using a B71 bone vibrator at 115 dB FL. Within a month of the initial test, fifteen subjects underwent mVEMP a second time. Results: The results showed that the BC-evoked mVEMP had a 100% response rate in all three frequencies. In both females and males, there was no significant difference across frequencies for P1 and N1 latencies (p > 0.05). There was also no gender difference for P1 latency, but N1 latency was shorter in females. The P1 – N1 amplitude was found to have significant differences across frequencies but no gender difference. Using intraclass correlation coefficient (ICC) values, the reliability of the BC-elicited mVEMP test-retest was assessed. It was observed that there is varied reliability for different response parameters ranging from poor to good. However, N1 latency was found to have the highest reliability among all the parameters (ICC > 0.75). Conclusions: The masseter VEMP can be recorded using a bone vibrator B71 transducer. However, the reliability of the masseter VEMP using the B71 bone vibrator is poor.