Doettl SM (2017) Peripheral Vestibular Evaluation - A New Horizon. Int J Clin Exp Otolaryngol. 3(1e), 1-3.
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International Journal of Clinical & Experimental Otolaryngology (IJCEO)
ISSN 2572-732X
Peripheral Vestibular Evaluation - A New Horizon
Editorial
Doettl SM
*
Associate Professor, The University of Tennessee Health Science Center, College of Health Professions, Department of Audiology and Speech Pathol-
ogy, Knoxville, TN, USA.
Vertigo, imbalance, and dizziness are reported with a 1-year
prevalence in the adult population of 48.3%, 39.1%, and 35.6%
respectively [1]. Falls in the elderly represent 2.8 million emergency
departments visits each year [2]. Reportedly, 5-8% of children will
experience vertigo in the general population [3-5]. These statistics
exemplify a signiicant public health issue with signiicant
implications across populations. There is universal agreement that
any investigation for reported vertigo, imbalance, and dizziness
begins with a thorough medical evaluation. Regardless of the
patient population or presenting symptoms it is imperative to irst
determine if any acute or chronic underlying medical conditions
exist. This is, of course, not a simple task as the sheer number of
possible pathologies resulting in vertigo, dizziness, and imbalance
is daunting.
Often, quantitative evaluations can be quite valuable in
guiding medical management decisions. Peripheral vestibular
evaluation speciically can provide quantitative information
as part of the overall medical evaluation for patients reporting
vertigo, dizziness, and/or imbalance. Electronystagmography
(ENG), videonystagmography (VNG) and rotary chair testing
(RCT) comprise a typical peripheral vestibular evaluation.
Electrophysiologic measures such as auditory brainstem response
(ABR) and electrocochleography (ECOG) may also be useful in
the evaluation of select peripheral vestibular disorders. These
protocols, in the absence of additional techniques, provide
information about peripheral vestibular function and in many
cases, prove effective and eficient. Of course, these techniques
also have inherent challenges that can limit their overall
effectiveness across a wide range of populations in both the clinic
and in the scientiic community.
When assessing for peripheral vestibular hypofunction, either to
conirm or rule out dysfunction, ENG/VNG and RCT only assess
the horizontal semicircular canals (SCCs) and the superior division
of vestibular nerve of the VIII cranial nerve. Additionally, caloric
irrigation is an evaluation of non-physiologic low-frequency
stimulation of the horizontal SCCs with RCT representing low-
to mid-frequency stimulation. Neither caloric irrigation or RCT
provide high-frequency stimulation. ABR evaluations can be
quite valid for use in assessing patients for acoustic neuroma/
vestibular schwannoma (AN/VS), however imaging studies can
also conirm AN/VS and it is exceedingly rare, reported to occur
with 19 tumors per million per annually [6]. ECOG testing, used
speciically in cases of suspected Meniere’s disease (MD), can
be technically challenging and has been reported, when using
extra tympanic measurement, to have poor sensitivity (71%), and
especially in the early symptomatic period [7, 8]. When positive
indings suggesting peripheral vestibular dysfunction are noted
using these techniques they are quite valuable to proper diagnoses
and management. However, due to the above noted factors these
tests with negative indings for peripheral vestibular dysfunction
can result in false negative indings and/or the inability to
conidently rule-out dysfunction.
Peripheral vestibular evaluation technology has advanced,
improving the ability to fully assess the peripheral vestibular
system. Speciically, Video Head Impulse Testing (VHIT) and
Vestibular Evoked Myogenic Potentials (VEMPs) have been
added to the vestibular test battery. These tests have expanded the
available information to include high-frequency stimulation, the
function of the posterior SCCs, anterior SCCs, inferior division
of the vestibular nerve of the VIII cranial nerve, the saccule, and
the utricle. These tests combined with the traditional vestibular
test battery allow for a more complete peripheral vestibular
evaluation to either conirm peripheral dysfunction or rule-out
vestibular involvement.
The VHIT utilizes video-oculography to allow for recording and
detailed analysis of the vestibular-ocular relex (VOR) for gain
and catch-up saccades with high-frequency stimulation for all 6
semicircular canals independently [9-11]. VHIT provides the only
clinically available method for assessing the posterior and anterior
SCCs in a quantitative manner. VEMP evaluations (cervical and
ocular) provide an evaluation of saccule and the inferior division
of the vestibular nerve of the VIII cranial nerve and utricle and
*Corresponding Author:
Steven M. Doettl, Au.D., CCC-A,
Associate Professor, The University of Tennessee Health Science Center, College of Health Professions, Department of Audiology and Speech Pathology, Knoxville, TN 37996, USA.
E-mail: sdoettl@uthsc.edu
Received: June 15, 2017
Published: June 21, 2017
Citation: Doettl SM (2017) Peripheral Vestibular Evaluation - A New Horizon. Int J Clin Exp Otolaryngol. 3(1e), 1-3. doi: http://dx.doi.org/10.19070/2572-732X-170002e
Copyright: Doettl SM
©
2017. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution
and reproduction in any medium, provided the original author and source are credited.