Pediatric emergency medicine trisk 0542 0542
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CHAPTER 24 ■ DIZZINESS AND VERTIGO
SOFIA CHAUDHARY, THERESA A. WALLS
INTRODUCTION
Dizziness can be a vague term that patients use to describe nonvertiginous
disturbances (pseudovertigo) such as lightheadedness, presyncope, intoxication,
ataxia, visual disturbances, unsteadiness, weakness, stress, anxiety,
hyperventilation, depression, and fear. True vertigo is the perception that the
environment is rotating relative to the patient or that the patient is rotating relative
to the environment. It can be immensely disturbing, even frightening, to patients
and their families. Preverbal children, unable to articulate the sensation, may be
irritable, may vomit, or may prefer to lie still. Even older children and adults may
have difficulty describing the sensation of vertigo.
Patients may present with dizziness as an isolated complaint or as part of a
constellation of symptoms related to an underlying illness. When evaluating a
child complaining of dizziness, the practitioner should listen carefully to the
details of the history as these may allow distinguishing true vertigo from
pseudovertigo. The key element in the history that strongly suggests true vertigo
is the subjective sense of rotation. Often, the best response to a chief complaint of
being dizzy is to say, “Tell me what you mean by ‘dizzy.’” Initial vague
complaints often become more concrete, and the underlying diagnosis may
become increasingly clear.
PATHOPHYSIOLOGY
True vertigo arises from a disturbance in either the peripheral or central
components of the vestibular system. The two peripheral sensory organs of the
system (together known as the labyrinth) are the semicircular canals (stimulated
by rotary motion of the head) and the vestibule (stimulated by gravity). Both
organs lie near the cochlea within the petrous portion of the temporal bone. The
proximity of the vestibule and cochlea explains the frequent association of vertigo
with hearing impairment.
Afferent impulses from these organs travel via the vestibular portion of the
eighth cranial nerve to the vestibular nuclei in the brainstem and in the
cerebellum. Efferent impulses travel through the vestibulospinal tract to the
peripheral muscles (helping to maintain balance and position sense) and also
within the medial longitudinal fasciculus to cranial nerves III, IV, and VI
