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Figure 17–11. SP increase upon fenestrating the posterior canal prior
to plugging to treat benign paroxysmal positional vertigo.
first four cases we were able to document intraoperative reductions of the SP/AP ratio with the completion
of the repair from an abnormally elevated ratio to a
normal ratio. Thus, in our very first case, the ratio was
reduced from 0.62 to 0.25, the second case from 0.56 to
0.32, and the third from 0.84 to 0.36; in the fourth case,
with a larger SP than AP, the ratio declined from 1.48 to
0.10. In 23 of the next 29 consecutive cases (24 repaired
via a middle-fossa approach, and 5 via a transmastoid
approach), we documented an intraoperative normalization of the SP/AP ratio, which was maintained until
the end of the case. In three cases operated via the
transmastoid approach, fluid in the middle ear during
surgery affected the accuracy of the ECochG; therefore,
ECochG was not useful intraoperatively. In three additional cases, the SP/AP ratio initially decreased and
then inexplicably increased gradually following repair.
The surgeon inspected the site to ascertain a complete
occlusion of the dehiscence, which was confirmed.
Therefore, it is not clear what created that late increase
in the SP/AP ratio. However, in all 6 cases where the
SP/AP ratio was unreliable due to fluid in the middle
ear, or in those where the SP/AP increased again following repair, the ratio was normal postoperatively
when follow-up ECochG was carried out in the outpatient clinic.
Figure 17–12 illustrates an intraoperative sequence
of ECochG during the repair of a superior canal dehiscence. Initial values prior to occlusion for the SP/AP
ratio ranged from 0.86 to 0.68, all considered to be
abnormal. At the conclusion of the repair, the ratio normalized to a value ranging from 0.2 to 0.32. This normal
value was maintained until the end of the case and confirmed again postoperatively when the ECochG was
repeated in the outpatient clinic. It is also of note that
following the repair this patient was symptom free.
SUMMARY
ECochG is a useful and effective clinical tool in the evaluation, treatment planning, and treatment effectiveness
confirmation in patients with balance disorders. In particular, ECochG is useful in the management of patients
suspected of endolymphatic hydrops/Ménière’s
disease and third-window conditions. One of the
important properties of ECochG is that it provides earspecific information, and the results are not affected by
the condition of the contralateral ear. As such, ECochG
can be useful in determining which side may cause the
symptoms related by the patient, in those situations
where vestibular testing provides equivocal information regarding the laterality of the lesion. Tympanic
ECochG is well suited to both outpatient and intraoperative applications. It is well accepted by patients as it
is not uncomfortable, invasive, or traumatic. There is a
certain level of technical skill necessary involving man-
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REFERENCES
Al-Momani, M. O., Ferraro, J. A., Gajewski, B. J., & Ator, G.
(2009). Improved sensitivity of electrocochleography in
the diagnosis of Meniere’s disease. International Journal
Figure 17–12. ECochG intraoperative monitoring sequence in
SSCD repair.
ual dexterity, in addition to a good working knowledge
of clinical auditory neurophysiology. It is imperative
that the tympanic electrode be introduced via microscopic visualization of the ear canal and tympanic
membrane. It is unadvisable to introduce the electrode
“blindly” into the ear canal: This could result in patient
discomfort and the electrode not reaching the tympanic
membrane, especially in narrow and in extremely
curved ear canals. If the electrode makes contact with
the ear canal only, it is no more effective than the ineffective tiptrode. Health care providers such as audiologists can be effectively trained to carry out this test in
an optimal manner; however, this type of training may
have to take place postgraduation, as such experience
cannot be obtained in most typical audiology training
programs. It is important to note that operator skill can
greatly influence the quality of the measurement and
the efficacy of this diagnostic test.
of Audiology, 48(11), 811–819. https://doi.org/10
14992020903019338
Arts, H. A., Adams, M. E., Telian, S. A., El-Kashlan, H., &
Kileny, P. R. (2008). Reversible electrocochleographic
abnormalities in superior canal dehiscence. Otology &
Neurotology, 30(1), 79–86.
Aso, S., Watanabe, Y., & Mizukoshi, K. (1991). A clinical study
of electrocochleography in Menière’s disease. Acta Oto-
Laryngologica, 111(1), 44–52.
Coats, A. C. (1981). Summating potential amplitude in
Meniere and non-Meniere ears. Archives of Otolaryngology,
107(4), 199–208.
Committee on Hearing and Equilibrium. (1995). American
Academy of Otolaryngology–Head and Neck Surgery
(AAO-HNS). Guidelines for the diagnosis and evaluation
of therapy in Meniere’s disease. Otolaryngology–Head and
Neck Surgery, 113, 181–185.
Dallos, P. (1976). Cochlear receptor potentials. In R. Ruben
(Ed.), Electrocochleography (pp. 5–21). Baltimore, MD: University Park Press.
Dauman, R., Aran, J. M., Charlet de Sauvage, R., & Portmann,
M. (1988). Clinical significance of the summating potential
in Meniere’s disease. American Journal of Otology, 9(1), 31–38
Davis, H., Deatherage, B. H., Eldredge, D. H., & Smith, C.
A. (1958). Summating potentials of the cochlea. American
Journal of Physiology, 195(2), 251–261.
Eggermont, J. J. (1976). Summating potentials in electroco-
chleography: Return to hearing disorders. In R. Ruben
(Ed.), Electrocochleography (pp. 67–89). Baltimore, MD:
University Park Press.
Ferraro, J. A. (2010). Electrocochleography: A review of
recording approaches, clinical applications and new findings in adults and children. Journal of the American Acad-
emy of Audiology, 21(3), 145–152.
Ferraro, J., Best, L. G., & Arenberg, I. K. (1983). The use of
electrocochleography in the diagnosis, assessment, and
monitoring of endolymphatic hydrops. Otolaryngology
Clinics of North America, 16(1), 69–82.
Guttman, J., & Barrera, S. E. (1934). Persistence of cochlear
electrical disturbance on auditory stimulation in the presence of cochlear ganglion degeneration. American Journal
of Physiology, 109, 704–708.
Jewett, D. L., & Williston, J. S. (1971). Auditory-evoked far
fields averaged from the scalp of humans. Brain, 94(4),
681–696.
Lempert, J., Wever, E. G., & Lawrence, M. (1947). The cochleo-
gram and its clinical application: A preliminary report.
Archives of Otolaryngology–Head and Neck Surgery, 45, 61–67.
Margolis, R. H., Rieks, D., Fournier, E. M., & Levine, S. E.
(1995). Tympanic electrocochleography for diagnosis of
Menière’s disease. Archives of Otolaryngology–Head and
Neck Surgery, 121(1), 44–55.
.3109/
456 BAlAnCE FunCtion AssEssmEnt And mAnAgEmEnt
https://t.me/medicina_free
Merchant, S. N., Rosowski, J. J., & McKenna, M. J. (2007).
Superior semicircular canal dehiscence mimicking otosclerotic hearing loss. Advances in Oto-Rhino-Laryngology,
65, 137–145.
Minor, L. B., Schessel, D. A., & Carey, J. P. (2004). Ménière’s
disease [Review]. Current Opinion in Neurology, 17(1), 9–16.
Minor, L. B., Solomon, D., Zinreich, J. S., & Zee, D. S. (1998).
Sound- and/or pressure-induced vertigo due to bone
dehiscence of the superior semicircular canal. Archives of
Otolaryngology–Head and Neck Surgery, 24(3), 249–258.
Mori, N., Asai, H., & Sakagami, M. (1993). The role of sum-
mating potential in the diagnosis and management of
Meniere’s disease. Acta Oto-Laryngologica (Stockholm),
501(Suppl.), 51–53.
Murphy, M. P., & Gates, G. A. (1999). Measuring the effects of
Meniere’s disease: Results of the Patient-Oriented Severity
Index (MD POSI) version 1. Annals of Otology, Rhinology,
and Laryngology, 108(4), 331–337.
Rauch, S. D., Merchant, S. N., & Thedinger, B. A. (1989).
Meniere’s syndrome and endolymphatic hydrops. Doubleblind temporal bone study. Annals of Otology, Rhinology,
and Laryngology, 98(11), 873–883.
Rosowski, J. J., Songer, J. E., Nakajima, H. H., Brinsko, K. M.,
& Merchant, S. N. (2004). Clinical, experimental and theoretical investigations of the effect of superior semicircular
canal dehiscence on hearing mechanisms. Otology & Neu-
rotology, 25, 323–332.
Ruben, R. J., Elberling, C., & Salomon, G. (1976). Electroco-
chleography. Baltimore, MD: University Park Press.
Terkildsen, K., Osterhammel, P., & Huis in’t Veld, F. (1973).
Far field electrocochleography, electrode positions. Scan-
dinavian Audiology, 2, 141–148.
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Pediatric Vestibular Testing
Kristen Janky and Neil T. Shepard
introduCtion
Presented in this chapter are techniques and interpretation of the results for assessing children with problems
of dizziness and balance dysfunction. First, there is a
need to define what is meant by a child — when are the
testing and interpretations of vestibular and balance
function assessment for the adult appropriately applicable to “a child”? This question could be addressed by
age alone, but it seems logical that the approach should
be by the maturational status of the underlying peripheral sensory end organs and the neurological substrate
that needs to respond to the inputs from the sensory
end organs. Using this premise we would define the
need for an alternative approach for testing and alternative normative data at different ages for the child.
The peripheral vestibular system is anatomically
fully developed at birth. Physiologically the vestibuloocular reflex (VOR) functions at a level similar to the
adult, but there is evidence to suggest that there is a
maturational effect of the VOR, which may require
age-appropriate normative ranges (see the discussion
below on use of rotary chair in the laboratory testing
section). This is, however, not the case for the visual
system’s ability to capture small targets via saccades
or track targets in a smooth manner. The performance of
these tasks is not well developed for smooth pursuit or
saccades until upward of 4 to 6 months (Jacobs, Harris, Shawkat, & Taylor, 1997; Von Hofsten & Rosander,
1997) with the ability to attend to large moving targets
in repeated tracking manner (optokinetic [OKN] nystagmus) seen by 2 to 4 months (Valmaggia et al., 2004).
However, all of these tasks are estimated to not have
full adult development until much later
4 years (Valmaggia et al., 2004) and smooth pursuit up
to preadolescence (Katsanis, Iacono, & Harris, 1998;
Tajik-Parvinchi, Lillakas, Irving, & Steinbach, 2003).
Therefore, saccade tasks and smooth pursuit tracking
tasks with typical small targets are not acceptable for
use in the child under age 6 months with the use of
adult normative ranges; age-specific normative ranges
are needed (Mezzalira, Neves, Maudonnet, Bilecki, &
de Avila, 2005; Valmaggia et al., 2004). OKN stimuli can
be used for the very young child with a sinusoidal protocol as a substitute for smooth pursuit (see discussion
in Chapter 10 on OKN and its dominance by smooth
pursuit), yet the normative data range does not match
that of the adult until after age 4 (Valmaggia et al.,
2004). The ability of the child to maintain quiet stance
in an adult-like manner is fully developed between 7
and 10 years of age (Forssberg & Nashner, 1982; Woollacott, Debu, & Mowatt, 1987). Therefore, adult normative data for postural control and gait tasks are not
applicable to the child until pre-teen to mid-teen years.
Interestingly, even though the peripheral vestibular system and the visual systems are fully functional at
the adult level early in development (age <24 months),
the change in the strategy for use of these cues from a
child set of rules to the adult integrated set of internal
rules occurs slowly between 3 and 6 years of age and
is not considered complete until age 7.5 to 8 (Forssberg
& Nashner, 1982). These changes in the use of visual,
proprioceptive/somatosensory and vestibular cues
for maintaining upright stance are parallel with the
changes in linguistic and syntactic child rules to the
adult rules over the same ages. Therefore, although
the VOR can be evaluated at birth by rotary chair and
— OKN about
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caloric tests and saccade and smooth pursuit tasks by
age 4 years, all with expected adult normative ranges,
the complexity for evaluating integrated postural control assessment by the adult normative ranges needs to
wait until age 15. Yet, the same tools for this task such
as dynamic posturography and other developmental
assessments specific to balance and ambulation are
applicable to children from age 3, but this normative
range specific to the age of the child is different from
that of the adult (Christy, Payne, Azuero, & Formby,
2014; Rine, 2007). For all of the assessment tools for the
peripheral and central vestibular system, and those
for postural control, modifications in the testing protocol are needed to make the tests of interest to young
children (<7) similar to the modifications used for the
evaluation of hearing for this same age group. For the
young child one must remember that the next test that
you acquire may well be the last test you are going to
get. Therefore, not only is the test used of importance
but so is the selection of the order of evaluations to
be used, which must be given some thought for each
child seen. The concept of planning the evaluation of
the child will be discussed in more detail below.
We now turn our attention to the estimates of incidence of vestibular, balance, and gait abnormalities in
children 15 years of age and younger. Because of the
inescapable anatomical and physiological relationship
between the auditory and peripheral vestibular systems, and the better-documented information on hearing loss, we use hearing loss in children 15 and under
as an index for discussion of the incidence of problems
with balance and dizziness.
Incidence of Vestibular and
Balance Problems in Children
As a reference point the incidence of hearing loss in
children 6 to 19 years of age is estimated through the
third National Health and Nutrition examination survey. This survey from 1988 to 1994 gives an incidence
of 14.9% of children who have a slight or greater loss of
hearing, defined as 16 dB HL or greater loss. The majority of the loss was determined to be unilateral (Niskar et
al., 1998). In contrast there is not a nationwide estimate
of the incidence of vestibular and balance problems in
children partly because it is felt to be uncommon and
because of the difficulty of verifying the issue of a vestibular deficit in children under age 3 without extensive evaluations and expensive equipment. There are,
however, isolated studies that have tried to provide
estimates of dizziness in specific groups of children
(e.g., in 10-year-olds, suggesting a prevalence of 5.7%)
(Humphriss & Hall, 2011). In an extensive retrospective study of a pediatric health system over a four-year
interval (O’Reilly et al., 2010), records were searched
for encounters related to International Classification of
Diseases, Ninth Revision (ICD-9) codes related to balance disorders. This resulted in over 550,000 individual
entries. These were then searched for chief complaints
related to balance and other otologic/neuro-otologic
diagnoses. Out of the total patients, 1.03% had primary complaint related to balance issues. Out of this
group 35.8% were diagnosed with a vestibular disorder; 38% with peripheral, and 21% with central vestibular disorders. They went on to calculate the odds
ratio of syncope and found that to be 21 times higher
in the patients with unspecified dizziness than in the
general pediatric population. Also the odds ratio was
43 times higher for simultaneous presence of sensorineural hearing loss in those with peripheral vestibular
disorders than in the general pediatric group. In the
group with central vestibular disorders, the odds ratio
of headache complaints was 16 times higher than in the
general pediatric group.
In a recent systematic review with meta-analysis,
the differential diagnosis of “vertigo” in children was
investigated (Davitt, Delvecchio, & Aronoff, 2017).
Vertigo was defined as a sensation of environmental
motion known not to be occurring. The 22 papers that
met their inclusion criteria had a total of 2,726 children used for this review. This included children from
2 months to 19 years of age, but children with a preestablished condition associated with vertigo were not
included. The four most frequent diagnoses were: vestibular migraine (23.8%), benign paroxysmal vertigo of
childhood (a migraine precursor) (13.7%), idiopathic
(11.7%), and vestibular neuronitis/labyrinthitis (8.4%).
These four diagnostic categories accounted for 57% of
the 2,726 children used in this review. The remaining
43% of the children had diagnostic categories ranging
from posttraumatic vertigo (8.36%) to Ménière’s disease (3.01%) to benign paroxysmal positional vertigo
(2.64%) to the lowest group of airway infection (1.14%).
The overall estimate of the prevalence of dizziness and
balance problems in a school age population was 5.3%,
with an estimate of 72% in students in the twelfth grade
reporting at least one event of vertigo within the prior
three months (Li, Hoffman, Ward, Cohen, & Rine, 2016).
It is also suggested that the general occurrence of
dizziness in children is approximately that of adults,
but there is a difference in the frequency of presentation of the various forms of dizziness, to be discussed
in more detail below (Agrawal, Carey, Della Santina,
Schubert, & Minor, 2009; Kerber, Meurer, West, & Fendrick, 2008).
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DEVELOPMENT OF THE VESTIBULAR
AND
BALANCE SYSTEMS:
A GUIDE TO EVALUATION
Anatomically, the vestibular system is fully developed
at birth; however, maturation of our ability to maintain “balance” continues until 12 to 15 years. Balance is
attained with information from the visual, vestibular,
and proprioceptive (awareness and perception of our
body in space) systems. Each of these three systems
has an important role in the maintenance of overall
balance. Therefore, the maturation process includes
integration of information from these three systems
and is reflected in the attainment of gross motor milestones (i.e., the ability to sit, stand, walk, crawl, run,
and jump) as well as the integration of this information
for everyday ambulation and postural control. Pediatric assessments differ from those for adults because
these systems are at various stages of development in
children. Understanding this maturation process can
be helpful in interpreting tests of vestibular function as
well as the normal variation in gross motor milestone
development and postural control. As discussed below,
when vestibular loss occurs, it can cause a significant
disruption in the timeliness of this maturation process.
The vestibular system is responsible for initiating
three important reflexes: the vestibulo-ocular reflex
(VOR), the vestibulocollic reflex (VCR), and the vestibulospinal reflex (VSR). These reflexes are responsible for stabilizing the eyes during head movement,
the head during body movement, and the body for
postural control, respectively. Each of these reflexes
is explained below as well as the specific clinical tests
used to assess these reflex pathways.
Vestibulo-Ocular Reflex
The primary goal of the VOR is to maintain steady vision
during head movement. With the VOR, the vestibular
system detects head velocity and initiates an equal and
opposite eye movement. Specifically, the semicircular
canals (horizontal, anterior, and posterior) are responsible for detecting angular accelerations (i.e., moving the
head “yes” or “no”), while the otolith organs (utricle
and saccule) detect linear accelerations (i.e., accelerating in a car or airplane). In response to these types of
movements, the VOR maintains visual targets on the
fovea of the retina, where the sensitivity of the eye is the
greatest, for steady vision during movement.
The VOR is responsible for maintaining clear
vision in response to head movements that exceed
100 deg/s. When head movements are slower than
100 deg/s, or when the head is still, the ocular motor
system maintains images on the fovea of the retina.
The three primary reflexive eye movements that help
achieve this goal are smooth pursuit, saccade, and
OKN eye movements. For example, the smooth pursuit
system is responsible for maintaining clear vision during slow head movements and is able to track visual
targets moving up to approximately 100 deg/s, after
which the VOR takes over. The VOR reaches maturity in the first 6 to 12 months of life, while the ocular
motor system matures at a slower pace. Clinical tests
of the VOR include the video head impulse test (vHIT),
rotary chair, ocular vestibular-evoked myogenic potential (oVEMP), and caloric test. The ocular motor exam
is used to assess the visual system.
Vestibulocolic Reflex
The primary goal of the VCR is to use information from
the vestibular system to stabilize the head. Evidence
of the vestibular system’s role in stabilizing the head
is that children with significant vestibular loss are
delayed in the age they gain head control (Inoue et al.,
2013). Examinations of the VCR include the cervical
VEMP (cVEMP).
Vestibulospinal Reflex:
General Postural Control
The primary goal of the VSR is to stabilize the body
for postural control. This system is more complex as
it involves a larger number of connections to muscles
throughout the body (i.e., the arms, hands, legs, feet,
etc.). There are three primary tracts that make up the
VSR: the lateral vestibulospinal, medial vestibulospinal, and reticulospinal tracts. Given the strategy
changes discussed below, this system is not mature
until ages 12 to 15 years. Examinations of the VSR
include assessments of postural control, such as the
Sensory Organization Test (SOT) and tests of gross
motor development.
Gross Motor Developmental
Norms and Their Predictability of
Peripheral/Central Vestibular Loss
Vestibular loss leads to gross motor delay. Children
with vestibular loss hold their head upright, sit, stand,
walk, and crawl later than their age-matched, normal
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developing peers (Abadie et al., 2000; Inoue et al., 2013;
Janky, Thomas, et al., 2018; Kaga, 1999; Kaga, Shinjo,
Jin, & Takegoshi, 2008). Typically developing children
sit, stand, and walk at 6 to 8 months, 10 to 11 months,
and 10 to 12 months, respectively, while children with
vestibular loss sit independently as late 8 to 18 months,
stand independently by 9 to 20 months, and walk independently at 12 to 33 months (Kaga, 1999). There is a
relationship between degree of vestibular loss and
degree of gross motor delay. Children with greater vestibular loss achieve gross motor milestones later than
those with less severe vestibular loss (Abadie et al.,
2000; Janky, Thomas, et al., 2018). Children categorized
on rotary chair as having mild-to-moderate vestibular
loss sat independently at 8 months and walked independently at 15 months, whereas children categorized
as having bilateral vestibular loss sat independently
at 11 months and walked independently at 20 months
(Janky, Thomas, et al., 2018). When coupled with other
conditions (i.e., cognitive impairment or other health
issues), these milestones are often met even later (Abadie et al., 2000; Kaga, 1999). For example, in 17 children diagnosed with coloboma-heart-atresia-growth
retardation-genital-ear (CHARGE) syndrome, all children had some degree of vestibular loss and achieved
their motor milestones later than typically developing
peers (mean age): holding head steady (6.8 months),
stable sitting (14 months), standing supported (19.8
months), standing unsupported (23.9 months), and
walking indoors (29.8 months) (Abadie et al., 2000).
Gross motor acquisition can also be halted or delayed
at the time of cochlear implantation (De Kegel, Maes,
Van Waelvelde, & Dhooge, 2015).
Gross motor milestones predict vestibular loss in
children with hearing loss. Early studies demonstrated
that performance on the tandem Romberg was predictive of vestibular loss in children (Brookhouser, Cyr, &
Beauchaine, 1982). Christy, Payne, Azuero, and Formby
(2014) report the use of several clinical measures for
predicting vestibular loss, with the best outcome being
standing on foam with eyes closed; using a cutoff value
of 20 seconds yielded a sensitivity of 88% and specificity
of 92%. Similarly, Oyewumi et al. (2016) suggest using
the single leg stance to predict the presence of bilateral loss; using a cutoff value of four seconds yielded a
sensitivity of 90% and specificity of 100%. In younger
children, asking parents the age at which their child
first sat and walked independently can also be used
to predict vestibular loss. For age to sit, using a cutoff
value of 7.25 months yielded a sensitivity of 62% and
specificity of 81%; for age to walk, using a cutoff value
of 14.5 months yielded a sensitivity of 78% and specificity of 77% (Janky, Thomas, et al., 2018). Even ask-
ing parents if they are concerned about their child’s
gross motor function (yes/no) can be predictive. In
parents who reported concern for gross motor delay,
there was a higher likelihood of their child having
bilateral vestibular loss (odds ratio, 52.957), suggesting
that asking parents if they are concerned about their
child’s gross motor delay can be helpful for determining if vestibular loss is present (Janky, Thomas, et al.,
2018). Vestibular loss should be suspected if gross
motor delay exists or there is parent concern regarding gross motor delay, particularly when the child has
hearing loss.
Evidence is emerging regarding the relative contribution of the otolith organs in the development of
postural control. In typically developing infants, preliminary evidence suggests that the otoliths undergo
changes during development, which correlate with
walking (Wiener-Vacher, Toupet, & Narcy, 1996).
With the ability to assess otolith function via VEMP
(described below), infants with absent VEMP responses
walk later than those with present VEMP (Inoue et al.,
2013). Likewise, older children with present cervical
VEMP have better static balance than those with absent
cervical VEMP (De Kegel, Maes, Baetens, Dhooge, &
Van, 2012; Jafari & Asad, 2011; Shall, 2009). It should be
noted, however, that this relationship has not always
been consistently observed (Cushing, Papsin, Rutka,
James, & Gordon, 2008b). These findings are preliminary, and other factors, such as overall degree of vestibular system loss, should also be considered.
Although children with vestibular loss eventually meet their motor milestones, gross motor delays
can persist. Some speculate that gross motor delay as
a result of vestibular loss can be naturally overcome
in children due to the large degree of plasticity in the
developing brain (Kaga, Shinjo, Jin, & Takegoshi, 2008);
however, in some children gross motor delay has been
found to be persistent or even progressive, suggesting
that plasticity is not enough (Rine et al., 2000, 2004).
In older children, gross motor delays have been documented on standardized tests of motor proficiency,
such as the Bruininks-Oseretsky Test of Motor Proficiency II (BOT-2), and balance dysfunction has been
documented on the SOT. Children with both unilateral
and bilateral vestibular loss exhibit gross motor delay
(DeKegel et al., 2012).
Strategy Changes with Development
Visual, vestibular, and proprioceptive information
must be adequately integrated in order to maintain
balance and postural control. During development,
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the effective use of each of these systems changes as
children transition to adult-like strategies. Children
tend to be more dominant on their visual system in the
early years. Utilizing the SOT, described below, children have adequate use of somatosensory information
between 4 and 6 years of age; however, they are not
able to adequately use vision or vestibular information for postural control (Charpiot, Tringali, Ionescu,
Vital-Durand, & Ferber-Viart, 2010; Hirabayashi &
Iwasaki, 1995; Rine, Rubish, & Feeney, 1998). By ages
14 to 15, utilization of visual information is adult-like;
however, the effective use of vestibular information
is still continuing to mature (Hirabayashi & Iwasaki,
1995). There is some disagreement on the exact time
frame that children are able to mimic adult-like strategies, but this transition is thought to occur by ages 12
to 15 years (Peterka & Black, 1990; Peterson, Christou,
& Rosengren, 2006). It can take up to ages 10 to 15 for
final refinement, but the ability to integrate the three
inputs in an adult weighted manner emerges around
ages 7 to 8 (Forssberg & Nashner, 1982). Regardless of
the exact time frames, these findings collectively suggest that there is continued maturation of sensory integration (Casselbrant et al., 2010; Charpiot et al., 2010;
Hirabayashi & Iwasaki, 1995; Rine et al., 1998).
child. You typically get a single opportunity for obtaining data from a test being performed. Therefore, if the
dominant complaints from the parents/child by observation are related to gait difficulties and unsteadiness,
we would start the evaluation with a very brief review
of possible bilateral peripheral vestibular hypofunction via head thrust test. If negative, then move on to
evaluations of gait and postural control and then come
back to further evaluation of the VOR system. If a quick
screen for unilateral or bilateral peripheral involvement or the primary complaint is interpreted to imply
episodic events of vertigo, move first to the evaluation
of the VOR and then on to gait and balance evaluation.
The child with persistent verbal or action complaints related to balance or the possible onset of a vertigo event as witnessed by abnormal eye movement or
the child suddenly stopping playing and sitting quietly
is felt to be in need of a formal office and laboratory
evaluation. The child who has short duration symptoms that are not repeated over time may do well with
the direct office evaluation and the interview of the
child and parents for determination of what occurred.
History and Clinical Presentation
VESTIBULAR EVALUATION OF THE CHILD
As stated above, planning the evaluation can be more
important in the young child under age 5 than in the
older child or adult. Where we would have a similar
routine with the older child and adult that we would
proceed through, this is not the case with the younger
child. One needs to remember that the evaluation may
be more than a one-day process, especially for the very
young child under 2 years of age or the infant. For this
very young age group, the next result you obtain may
well be the last one you are going to get on that day.
Since it is possible that the child may have to return
the next day for completion of testing or would need to
return in 6 to 12 months as they are older and can participate in more evaluative studies, you do not want to
leave a memory in the child of a bad experience. Therefore, if the child becomes fussy and clearly does not
wish to continue to participate, then it is time to stop.
As with hearing evaluations in very young children,
the tasks performed need to keep the child’s attention
and be made age appropriate for the child — made fun
if possible. Whereas with older children and adults
we will repeat some of the testing multiple times for
best performance, this is not possible with the young
The following information is needed to assist in the
determination of the possible etiology of the balance
or vestibular disorder:
n Are the symptoms episodic or persistent in
nature?
n Do the symptoms seem to represent a sensa-
tion of movement of the child’s environment
or of the child within the environment?
n If the symptoms are episodic, how frequently
do they occur?
n If episodic, how long do the symptoms last
for a given episode or given exacerbation in
constant background symptoms?
n Is there a history of childhood diseases
since birth, disorders of the mother during
pregnancy, or any problems during or shortly
after the birth process?
n Are there any known or suspected hearing
loss issues?
The above information for the nonverbal child will
clearly need to be obtained from the parent. The
details of the sensations — whether in spells, duration of the spells, and frequency — may be difficult to
obtain. However, it is worth the investment in time, as
many times asking questions about the child’s general
462 BAlAnCE FunCtion AssEssmEnt And mAnAgEmEnt
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behavior, playing activities, and avoidances (such as
heights) can come together in a picture of what may
be happening as the parents reflect on what they have
observed. This also gives the child time to play in your
presence to start to become familiar with you and the
surroundings.
As the child starts to be able to verbalize, engaging
the child in helping to better define the above information, especially that of the sensation the child feels,
can be very useful. Be careful not to lead the child as
to what you are looking for in an answer. Then find
several ways to get the same information to see if the
responses are consistent. As children get up to 2 to 4
years of age, some can be very specific as to what it is
they are experiencing. As you can engage the child, it
is helpful in the interview so that the child is not left out
of the discussion and the discussion is not just about
and around the child but includes the child. As the
child gets older, the questions can start to be focused
to give information that would be more specific to the
disorders that could be occurring based on what causes
for dizziness are the most common (discussed below).
Direct Office Examination
The office examination can be useful for the child of any
age. The older the child, the more aspects of the examination can be used, and the more reliable are the findings. Very little in the way of equipment is needed for
the basic office examination, but having a clown nose,
stickers, or other child toys can be quite useful to attract
and hold the child’s attention during the task at hand.
If the child will tolerate a gentle hold of the
chin by the parent, then watch for the eye
saccade movement. Again at ages under 2
to 3 months, the child may be involved in
a searching behavior with the eyes before
capturing the target.
n OKN nystagmus — for the child under 4
months who may not be able to perform
pursuit, this could be an alternative to
demonstrate pursuit ability (see discussion
in the introduction). For this, have a strip
of cloth with repeating stickers that can be
drawn slowly across the child’s visual field,
and if the nystagmus can be generated, this
would be a good indicator of gross ability
of smooth pursuit. If no nystagmus can be
generated, nothing can be decided from a
negative result.
n Rotational chair — for this, the child needs to
sit on the examiner’s lap facing the examiner.
The examiner is in a swivel office chair.
Without any visually attracting target, just
the examiner’s face, the chair is oscillated
back and forth looking for nystagmus. It
is important that the child’s eyes be on the
examiner and not looking elsewhere to avoid
OKN stimulation. At the young ages in this
group, the visual fixation suppression system
is not well developed, so you can typically
see nystagmus unless they have significant
bilateral hypofunction.
Child Walking Independently
Infant Through Start of Independent Walking
The following elements would be included in the typical office examination:
n Head thrust test — the infant/child on the
parent’s lap facing the clinician. This is where
having a sticker on the forehead or nose of the
clinician can be very helpful.
n Pursuit tracking — using a large sticker, see
if the child will follow the movement. This
ability may not be developed if the child is
under 4 months of age.
n Saccade testing — using two large and differ-
ent stickers or finger puppets, have one pop
up to the left and then as it disappears have
the other pop up to the right. If the child’s
head is free you would need to watch for
the eye movement first and then the head.
For this age grouping typically about 18 months or over,
the same elements in the direct examination given for
the younger child above would still be included. The
variations would be that smaller objects could be used
for pursuit, and saccade testing and the rotary chair
evaluation would now not be used in office format.
For the child at 6 years of age or older, then the same
activities would be used as in the adult but several
other office examination activities can be added that
have reasonable predictability for what would occur in
the formal laboratory tests discussed below
— the interested reader is referred to the recent work by Christy
et al. (2014).
For the child 18 months or over, we would vary
the head thrust test by having the child sit by himself or
herself in a chair or again on a parent’s lap and get the
child to watch the examiner’s nose as we do in an adult
(Figure 18–1). Since the child can walk independently,
motor milestones can be used to look at normal motor
18. PEDIATRIC VESTIBULAR TESTING 463
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Figure 18–1. Example of a child and examiner in preparation for a bedside head thrust test.
gait activity (Rine, 2007). Also, we can now start to
perform the Modified Clinical Test for Sensory Interaction on Balance (Shumway-Cook & Horak, 1986). The
modification is performed with only four conditions:
standing on firm surface with and without vision, then
standing on a compliant surface (i.e., foam) with and
without vision. For the young child who will not keep
his or her eyes closed on command, the examiner and
child are together and a third person (typically the par-
Figure 18–2. Example of a child performing the modi-
TSIB standing on foam with visual fixation present.
fied C
ent) would take care of switching the lights on or off in
the room. Have the child hold loosely to the examiner’s
little finger so the examiner knows when the lights are
shut off if the child is swaying. Figure 18–2 illustrates
this setup with the child on a foam cushion.
Recording Technique: Video Versus Electrodes
There are two main techniques for recording eye movements during vestibular assessment: video goggles
(videooculography), which use infrared to track pupil
Laboratory Testing: What
Studies at What Ages
direction, and electrodes (electro-oculography), which
record the corneo-retinal potential. While video gog-
gles are preferred due to their increased resolution and
In children, vestibular loss can be congenital or acquired,
can occur with or without hearing loss, and can differentially affect the vestibular sensory structures (otoliths
versus semicircular canals). Therefore, the purpose
of vestibular assessment may be for determination of
(1) the pathophysiology of dizziness complaints, (2) the
etiology of hearing loss, or (3) the underlying cause of
gross motor delay. Although we have the capability to
ability to enable patients to keep their eyes open dur-
ing tasks without fixation, they are not always ideal
for use with children. Video goggles are expensive, are
often too big, or are not tolerated by small children, in
which case, electrodes must be used. It would be the
recommendation of the authors to utilize video goggles
whenever possible and defer to electrodes when video
is not an option.
assess each of the vestibular sensory structures independently with a combination of tests, it is important
Rotational Chair
to understand which assessments are appropriate for
children and at which age. Following is a description
of common vestibular assessments and normative data
across ages.
Rotary chair, using traditional paradigms, is an assess-
ment of the horizontal semicircular canals. One down-
fall of rotary chair is that it does not provide ear-specific
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