Pediatric emergency medicine trisk 138

drug or intoxicant use is important, as is a family history of migraine. Age of the
patient is especially useful—benign paroxysmal vertigo is unusual after age 5
years, whereas Ménière disease is unusual before age 10 years. The physical
examination focuses on the middle ear and on neurologic and vestibular testing.
Visualization of the external ear canal may reveal cerumen impaction, foreign
body, or zoster lesions (Ramsay Hunt syndrome). Perforation or distortion of the
tympanic membrane should be noted. A pneumatic bulb will enable the examiner
to see whether abrupt changes in the middle ear pressure trigger an episode of
vertigo, a suggestion that a perilymphatic fistula may be present (Hennebert sign).
The neurologic examination must be complete, focusing closely on the
auditory, vestibular, and cerebellar systems. Both vestibular and cerebellar
disorders may present with an unsteady gait. If there is a unilateral lesion, the
child will fall toward the side of the lesion. The two may at times be
distinguishable by the nature of the nystagmus (described below). If cerebellar
dysfunction is present, the patient may have dysmetria and ataxia. All cases of
suspected vestibular or cerebellar dysfunction require close follow-up evaluation
because of the risk of a posterior fossa mass.
Nystagmus is a highly specific sign for both central and peripheral vertiginous
disorders. A patient complaining of dizziness with vertigo may not have
nystagmus at the time that he or she is examined. Tests to elicit positional vertigo
and nystagmus can therefore be helpful in identifying and even distinguishing
central and peripheral vestibular dysfunction, particularly if the tests elicit or
increase the patient’s complaint.
Nystagmus should be sought in all positions of gaze and with changes in head
position. The Nylen–Hallpike test can be used to elicit nystagmus if not apparent
on initial examination. It is performed by moving a child rapidly from a sitting to
a supine position with the head 45 degrees below the edge of the examining table
and turned 45 degrees to one side. Nystagmus and a vertiginous sensation may
result as the vestibular system is stressed. Certain features of nystagmus may be
helpful in distinguishing central from peripheral vestibular dysfunction. In central
dysfunction, for example, onset of nystagmus is immediate; in peripheral

vestibular disorders, it is delayed. Central lesions are characterized by nystagmus
with the fast component toward the affected side and reversal of the fast
component when changing from right to left lateral gaze. Peripheral vestibular
disorders are characterized by a “jerk” nystagmus with the slow component
toward the affected side. Finally, visual fixation does not affect nystagmus from
central causes, but tends to dampen peripheral nystagmus.


FIGURE 24.1 Approach to the child with true vertigo. CT, computed tomography; TM,
tympanic membrane; CNS, central nervous system.

The cold caloric response tests for integrity of the peripheral vestibular system.
Slow and careful irrigation of either 100 mL of tap water 7°C below body
temperature or 10 mL of ice water into the external ear canal through a soft
plastic tube, with the child lying about 60 degrees recumbent, should induce a
slow movement of the eyes toward the stimulus and a fast movement away.
Instillation of warm water (44°C) will cause an inverse reaction. Vestibular
damage will suppress the response on the affected side. Absence of nystagmus
indicates absence of peripheral vestibular function. The test is contraindicated if
the tympanic membrane is perforated.
Ancillary Tests
Laboratory investigations have a limited role in the evaluation of vertigo. Useful
initial tests include complete blood count, serum glucose, and an
electrocardiogram. Together, these may help identify patients with
pseudovertiginous conditions caused by anemia, hypoglycemia, and rhythm
abnormalities. Further laboratory testing may reveal diabetes or renal failure, both
of which have been associated with vertigo. Toxicologic testing including specific
anticonvulsant levels and an ethanol level, if indicated, may be helpful. A lumbar

puncture is indicated in cases of suspected meningitis or encephalitis, but imaging
may be required to rule out obstructive hydrocephalus from a posterior fossa mass
if there are cerebellar signs.
Radiologic imaging of the central nervous system, preferably by MRI for
adequate visualization of the posterior fossa and brainstem, is indicated in cases
of chronic and recurrent vertigo to exclude mass lesions. Children with vertigo
and an underlying bleeding diathesis or a predisposition toward ischemic stroke
(i.e., sickle cell disease) may also need an emergent cranial CT or MRI.
Posttraumatic vertigo, especially when accompanied by hearing loss or facial
nerve paralysis, is best assessed by CT that includes adequate images of the
temporal bone.
Some children with true vertigo will require referral for more extensive testing.
An EEG is indicated when vertigo accompanies loss of consciousness or other
manifestations of a seizure. Audiometry is indicated when vertigo accompanies
otalgia, hearing loss, or tinnitus. Specialized testing for nystagmus, including
electronystagmography, which measures eye movements at rest and at extremes
of gaze, can separate central from peripheral vestibular disorders. It may be
combined with caloric and positional testing.

MANAGEMENT
Most causes of vertigo remit spontaneously without therapy, but specific
disorders require treatment. Suppurative labyrinthitis, for example, is treated with
antibiotics if a bacterial etiology is suspected. An erosive cholesteatoma requires
surgical removal. Anticonvulsants may diminish vestibular and vestibulogenic
seizures. Motion sickness may respond to simple behavioral changes (e.g.,
encouraging children to look out the window).
Subspecialist consultation is indicated in certain situations. Neurosurgical
evaluation after trauma may be indicated in cases of suspected basilar skull
fracture. Suspected perilymphatic fistula, cholesteatoma, traumatic rupture of
tympanic membrane, or complicated otitis media may merit otorhinolaryngologic

evaluation. Neurologists may be helpful in cases of suspected seizure or migraine.


FIGURE 24.2 Approach to the child with pseudovertigo. EKG, electrocardiogram.

Children with severe or recurrent attacks of vertigo may require treatment with
specific medications. The antihistamines dimenhydrinate (12.5 to 25 mg orally
every 6 to 8 hours, maximum dose 75 mg per day for ages 2 to 6 years and 25 to
50 mg every 6 to 8 hours for ages 6 to 12 years, maximum dose 150 mg per day)
and meclizine (12.5 to 25 mg orally every 12 hours in children older than 12
years of age) may be helpful. Concomitant use of a benzodiazepine such as
diazepam (0.1 to 0.3 mg/kg/day orally divided every 6 to 8 hours, maximum 10
mg per dose) as a sedative may be necessary in severe cases.

Pseudovertigo
Pseudovertigo ( Fig. 24.2 ) refers to a broad array of symptoms such as
lightheadedness, presyncope, intoxication, ataxia, visual disturbances,
unsteadiness, stress, anxiety, and fear. Uniformly absent are a sense of rotation
and ocular nystagmus. Underlying causes are numerous; several of the most
common causes are listed in Table 24.3 (see also discussions of syncope in
Chapter 76 Syncope ). Careful consideration of the patient’s age, gender, detailed