Changes in cochlear function related to acoustic stimulation of cervical vestibular evoked myogenic potential stimulation
2016 (English)In: MEMRO 2015 – Basic science meets clinical otology, Elsevier, 2016, Vol. 340, 43-49 p.Conference paper (Refereed)
Evaluation of cervical evoked myogenic potentials (c-VEMP) is commonly applied in clinical investigations of patients with suspected neurotological symptoms. Short intense acoustic stimulation of peak levels close to 130 dB SPL is required to elicit the responses. A recent publication on bilateral significant sensorineural hearing loss related to extensive VEMP stimulation motivates evaluations of immediate effects on hearing acuity related to the intense acoustic stimulation required to elicit c-VEMP responses. The aim of the current study was to investigate changes in DPOAE-levels and hearing thresholds in relation to c-VEMP testing in humans. More specifically, the current focus is on immediate changes in hearing thresholds and changes in DPOAE-levels at frequencies 0.5 octaves above the acoustic stimulation when applying shorter tone bursts than previously used. Hearing acuity before and immediately after exposure to c-VEMP stimulation was examined in 24 patients with normal hearing referred for neurotologic testing. The stimulation consisted of 192 tonebursts of 6 ms and was presented at 500 Hz and 130 dB peSPL. Bekesy thresholds at 0.125-8 kHz and DPOAE I/O growth functions with stimulation at 0.75 and 3 kHz were used to assess c-VEMP related changes in hearing status. No significant deterioration in Bekesy thresholds was detected. Significant reduction in DPOAE levels at 0.75 (0.5-1.35 dB) and 3 kHz (1.6-2.1 dB) was observed after c-VEMP stimulation without concomitant changes in cochlear compression. The results indicated that there was no immediate audiometric loss related to c-VEMP stimulation in the current group of patients. The significant reduction of DPOAE levels at a wider frequency range than previously described after the c-VEMP test could be related to the stimulation with shorter tone bursts. The results show that c-VEMP stimulation causes reduction in DPOAE-levels at several frequencies that corresponds to half the reductions in DPOAE levels reported after exposure to the maximally allowed occupational noise for an 8 h working day. Consequently, extended stimuli intensity or stimulation repetition with c-VEMP testing should be avoided to reduce the risk for noise-induced cochlear injury.
Place, publisher, year, edition, pages
Elsevier, 2016. Vol. 340, 43-49 p.
Hearing Research, ISSN 0378-5955
VEMP, Noise, DPOAE, Hearing, Tone burst
IdentifiersURN: urn:nbn:se:liu:diva-132674DOI: 10.1016/j.heares.2015.12.022ISI: 000386417900006PubMedID: 26724755OAI: oai:DiVA.org:liu-132674DiVA: diva2:1048305
7th International Symposium on Middle Ear Mechanics in Research and Otology (MEMRO), Aalborg, Denmark, July 1-5, 2015