Vestibular Evoked Myogenic Potential (VEMP) in Individuals with Noise Induced Hearing Loss (NIHL)

Abstract

The present study was aimed to evaluate the functioning and susceptibility of the saccule in individuals with Noise Induced Hearing Loss (NIHL) using Vestibular Evoked Myogenic Potentials (VEMPs) 30 individuals (60 ears) with normal hearing sensitivity (control group) and 30 (57 ears) individuals with NIHL (clinical group) in the age range of 25-50 years were taken. All the individuals were tested on a test battery including case history, PTA, Immittance, TEOAEs, ABR & VEMP. 2 questionnaires were administered to obtain information about history of noise exposure and presence/absence of vestibular symptoms. The results showed that VEMP in NIHL group was present in 61.4%. There was statistically significant prolongation of p13 but not for the n23 latency, reduced amplitude for both p13-n23 complex and TEOAE for the clinical group in comparison to the control group. VEMP correlated with the vestibular symptoms in 33 out of 57 ears. VEMP did not correlate with the severity of the hearing loss (HL) for both ears. However, for degree of HL from mild to severe, the frequency of presence of VEMP response decreased. The TEOAE amplitudes are highly correlated with the severity of the HL for both ears. To conclude, the two parameters of VEMP, p13 latency and p13- n23 complex amplitude could be considered to show the effect of noise on saccular system which was obtained significantly different. VEMP is expected to be affected or absent in clients with the dysfunction of the vestibular system, as in the current study, all the individuals with symptoms of “Sensation that you are turning or spinning inside” and “Nausea or vomiting” had absent VEMP responses indicating saccular involvement in NIHL. It is also evident that the cochlea is more susceptible to noise in individuals with NIHL as TEOAE was absent in most of the client with NIHL.