Northeast Florida Medicine
Vol. 66, No. 1 2015
29
Otolaryngology
Introduction
Dizziness is a common and sometimes frustrating com-
plaint for the primary care provider. Dizziness can emanate
from several metabolic, neurologic, ophthalmologic and
otologic conditions.Medication interactions and psychiatric
cofactors can further complicate the differential.Many forms
of dizziness resolve spontaneously or can be managed once
the underlying cause is recognized. However, there exists
a subset of individuals who will complain of persisting
dizziness, vertigo or imbalance without a clear etiology. In
these cases, formal vestibular and balance assessment can
be enlightening. This article will highlight three advances
in the area of formal vestibular assessment and show how
they contribute to the management of the dizzy patient.
By way of review, each membranous labyrinth contains
five areas of sensory epithelia responsible for translating
head movement into useful neuronal signals (Table 1).
There are two otolith organs (utricle and saccule) and
three semicircular canals (anterior/superior, horizontal
and inferior/posterior). The otolith organs detect head
tilts and accelerations which drive vestibular spinal and
autonomic reflexes. The semicircular canals detect angular
head movements – head turns. In each ear, there are three
semicircular canals oriented in orthogonal planes. No
matter how the head turns about the cervical spine, the
semicircular canals will encode the movement and drive
compensatory eye movements via the vestibular ocular
reflex (VOR). The otolith organs also contribute to the
Three Advances in Vestibular Assessment
By David A. Zapala, PhD
1*
, Larry B. Lundy, MD
2
, Megan J. Kobel, AuD
3
1
Mayo Clinic College of Medicine, Mayo Clinic in Florida, 4500 San Pablo Road, Jacksonville, FL 32224, E-mail:
2
Mayo Clinic College of Medicine, Mayo Clinic in Florida, 4500 San Pablo Road, Jacksonville, FL 32224, E-mail:
3
Mayo Clinic College of Graduate Education, Mayo Clinic in Florida, 4500 San Pablo Road, Jacksonville, FL 32224, E-mail:
Address Correspondence to:
Mayo Clinic Vestibular Assessment
Mayo Clinic in Florida, 4500 San Pablo Road, Jacksonville, FL 32224
E-mail:
Telephone: (904) 953-0468
Fax: (904) 953-2489
Abstract:
Many forms of dizziness can be managed once the
underlying cause is recognized. However, individuals who complain
of persisting dizziness, vertigo or imbalance can pose a diagnostic
challenge. In these cases, formal vestibular and balance assessment
can be enlightening. This article summarizes three advances in
the evaluation and management of vestibular disorders: benign
paroxysmal positional vertigo (BPPV) assessment and management
using the Epley Omniax Chair; vestibular assessment using the
video head impulse and vestibular evoked myogenic potential tests;
and recognition of chronic subjective dizziness. Cases are presented
demonstrating how these advances have broadened the understanding
of dizziness and vestibulopathy.
Table 1.
Overview of vestibular labyrinthine structures and function.
Semicircular Canal
Otolith Organ
Primary
Sensory Input
Vestibular
Nerve Branch
Primary Reflex
Associated with Organ
Superior / Anterior
Angular tilt
(forward directed)
Superior
VOR
Horizontal
Yaw turn
Superior
VOR
Utricle
Static tilt and horizontal
linear acceleration
Superior
VSR / Autonomic
Posterior / Inferior
Angular tilt
(backward directed)
Inferior
VOR
Saccule
Vertical surge and
anterior / posterior tilts
Inferior
VSR / Autonomic
