Chapter
3
Diagnosing Dizziness and Vertigo:
The Physical Exam and Balance Testing
Steven
A. Telian, M.D.
University
of Michigan
Department of Otology
Ann Arbor, Michigan
Your doctor should have
a good idea of the probable diagnosis
before even proceeding on to the next
steps of examination and testing. Sometimes,
your doctor can even make the correct
diagnosis without any testing. Since almost
all causes of dizziness share some common
symptoms, it is the nature and pattern
of those symptoms at onset and then how
they develop over time that provides the
key to correct diagnosis and treatment.
So, please be very careful to organize
your experiences in your own mind and
as previously emphasized, pay careful
attention to answer the doctor’s
specific questions when giving your medical
history. Once your doctor has completed
the history, he or she will decide what
parts of the balance system need to be
examined and what tests will be obtained,
if any. My goal in this chapter is to
help you understand and anticipate what
will happen to you during this phase of
the evaluation.
The
Physical Examination for Dizziness
After a careful medical
history, you should receive an examination
from an otologist or neurotologist
(an ear surgeon who has taken additional
training in neurology, neurosurgery and
skull-base surgery to treat advanced problems
involving the ear, inner ear and the region
around the ear and the temporal bone).
This will include both an examination
of the ears, nose and throat as well as
a screening neurologic examination related
to the balance system. The entire exam
portion may be conducted efficiently in
about ten minutes, particularly if there
are few abnormalities noted.
Examination of the Ears, Nose and Throat
. . . If the appearance
of the ear is normal, but the medical
history suggests a possible injury to
the tiny membranes that retain the inner
ear fluids, the doctor may be suspicious
of a perilymphatic fistula. Perilymph
is the fluid contained in the outer chamber
of the inner ear and surrounds the inner
chamber that contains endolymph. A fistula
is a leakage of the perilymph fluid from
the inner ear to the air-filled middle
ear. The most common site for the perilymphatic
fistula is through the inner ear’s
round window membrane which is a thin
film in the cochlea.
If the doctor suspects
a perilymphatic fistula, he will
perform what is called a “fistula
test.” This test involves sealing
the ear canal, then gently increasing
and decreasing the pressure on the eardrum.
These pressure changes produce a similar
change in the middle ear pressure. When
there’s a fistula present, one of
the inner ear fluids (called perilymph)
may be able to leak out through an abnormal
connection between the middle ear and
the inner ear.
In such cases, the
pressure change in the middle ear will
irritate your inner ear, provoking dizziness.
The doctor will ask you if you experience
dizziness with positive pressure, negative
pressure or both. There may be another
member of the medical staff in the room
to observe your eyes during the fistula
test, since inner ear disturbances are
usually reflected in predictable but abnormal
movements of the eyes. . .
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