Question
A patient of mine has been using digital In-The-Ear hearing aids bilaterally for the past 6 months. He has previously used analog programmable In-The-Canal hearing aids bilaterally. Since he got fitted with the In-The-Ear hearing aids, he is noticing dizziness/vertigo, which goes away in few hours to a couple of days after he takes out his ITEs. He doesn't get vertigo/dizziness when he uses his ITCs. he hasn't consulted an ENT yet, however his primary care physician has suggested, it may be related to ITE hearing aids, as they occupy more space in the ears and may create more vibrations. Any suggestions/recommendations/experiences by the experts will be appreciated. Thank you.
Answer
I would start with a careful analysis of the output of the ITE's. It is likely that the output of the ITE is quite a bit higher than the ITC's he was using previously. If that is true, then the next question would be is the sound pressure mechanically stimulating the vestibular system either through a normal route of sound conduction (e.g. is the sound stimulating the saccule directly?) or through an abnormal route of sound conduction to the vestibular system (i.e. perilymphatic fistula? Superior semicircular canal dehiscence?). Regardless of the cause, this patient deserves a consultation with a neurotologist who has experience evaluating patients with sound-evoked dizziness. Audiology can contribute to the diagnostic evaluation with comprehensive audiometry, electronystagmography and vestibular evoked myogenic potentials (VEMP). The patient may need high resolution CT scanning in order to sort-out superior SCC dehiscence, and may need exploratory tympanotomy to rule-out the PLF. I would encourage you to read a recent paper by Cox et al. (JAAA, 12: 11-16, 2003) and to the following website: www.tchain.com
Dr. Gary Jacobson is Professor and Director of the Division of Audiology at the Vanderbilt Bill Wilkerson Center at Vanderbilt University Medical Center. Prior to this he was the Director of the Division of Audiology, and Adjunct Staff in the Department of Neurology for the Henry Ford Health System in Detroit, Michigan.
Dr. Jacobson is a Past President of the American Society of Neurophysiological Monitoring, and currently serves on the Scientific Advisory Board and Board of Directors of the American Tinnitus Association. He is the past-editor of the American Journal of Audiology, (American Speech-Language Hearing Association) and an Assistant Editor (Evoked Potentials) for the Journal of the American Academy of Audiology (American Academy of Audiology). He is on the Editorial Board of the journals Brain Topography and Seminars in Hearing and is an Ad Hoc reviewer for 10 other scientific journals. He has authored and co-authored over 100 publications that cover the areas of tinnitus, dizziness, auditory function, outcome measures development, brain mapping and intraoperative neurophysiology He is co-editor of the text Handbook of Balance Function Testing (Thomson Singular). He is a Fellow of the American Speech-Language Hearing Association, and, most recently, was recipient of the Jerger Career Award for Research in Audiology from the American Academy of Audiology.
