Semicircular Canal Pressure Changes During High-intensity Acoustic Stimulation

Abstract

High sound pressure levels were recorded in the semicircular canals with sound stimulation, suggesting that similar acoustical energy is transmitted to the semicircular canals and the cochlea. Since these intralabyrinthine pressures exceed intracochlear pressure levels, our results suggest that the vestibular end-organs may also be at risk for injury during exposure to high-intensity acoustic stimuli known to cause trauma in the auditory system.

Intracochlear pressure measurements during acoustic shock wave exposure

“…Temporal bone preparation procedures were similar to several recent reports from our laboratory (e.g. Deveze et al, 2010; Greene et al, 2017; Greene et al, 2015; Mattingly et al, 2015; Maxwell et al, 2017). Briefly, the temporal bones were prepared bilaterally: The pinna and surrounding skin were reflected during preparation but left intact.…”

Lateral Semicircular Canal Pressures During Cochlear Implant Electrode Insertion: a Possible Mechanism for Postoperative Vestibular Loss

“…Temporal bone specimens were prepared as previously described by our laboratory 12,17–24 . After overnight thawing in warm water, intact whole cadaveric heads were inspected to rule out injury or disease.…”

“…Given the interconnected nature of the fluid spaces in the inner ear, it would follow that these same high level pressure changes may also propagate through the vestibular labyrinth. Though we have previously demonstrated that high-level acoustic stimuli can cause pressure changes in the vestibular system in the absence of pathologic canal dehiscence in cadaveric specimen 17 , it is unknown if CI insertion-related pressure changes are transmitted to the vestibular end organs. To the best of our knowledge, no intralabyrinthine measurements specifically examining electrode insertion-related pressure changes within the vestibular system have been reported previously.…”

Perception of threshold-level whole-body motion during mechanical mastoid vibration

“…So, it could be possible that the structural asymmetries in the orientation of the SCC affects the fluid dynamics of the endolymph differently on the two sides, which in turn causes imbalance in the displacement of the hair cells and the activation of the vestibular neurons, resulting in perceptual bias. Bone conducted vibration is proposed to activate the vestibular receptors by modulating the fluid pressure [64] and producing pressure waves that travel through the inner ear and displace the hair bundles [18]. It is possible that these fluid pressure waves somehow corrected for the differences in the fluid dynamics of the SCCs produced by the structural asymmetries and thus reduced perceptual bias in the current study.…”