Dizziness In Orthopaedic Physical Therapy Practice: History And Physical Examination Page 17
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30Fukuda Step Test
field confrontation testing (CN II) had low sensitivity but
high specificity (97%) and positive predictive value (96%)
The Fukuda step test (Figure 3) assesses stability
when compared to automated perimetry
, indicating
71
during self-initiated movement by asking the patient
that a confrontation-method visual field test may only
to march 50 or 100 steps in place with the arms raised
have diagnostic value if positive. We found no further
in front to 90
and with the eyes closed. A patient with
0
data on reliability and validity of the CN examination.
a unilateral vestibular lesion will tend to rotate >30
0
Abnormal findings on the CN examination constitute a
toward the involved side
. Forward displacement of >50
64
reason for referral.
cm is also considered positive
. These unilateral lesions
67
include infarctions in the distribution of the anterior
and posterior inferior cerebellar arteries
. Bonanni and
34
Oculomotor Examination
Newton
found higher reliability for the 50-step than
68
To some extent, observation and the CN examina-
the 100-step protocol. Herdman and Whitney
noted
64
tion already test oculomotor function. They also allow
that there are many false positives and negatives. Fell
67
clinicians to note static abnormalities (strabismus) and
noted that the Fukuda step test is not a test specific to
ensure full range of movement for each eye before doing
vestibular lesions.
the oculomotor tests. No data on reliability and validity
of the oculomotor examination were found.
Cranial Nerve Examination
Observation for Spontaneous Nystagmus
Cranial nerve (CN) palsies may be present with central
Nystagmus can be defined as repetitive, back-and-
vestibular disorders and some peripheral vestibular disor-
forth, involuntary eye movements initiated by slow
ders. A CN examination may also serve as a non-provoca-
drifts away from the visual target
. It can be classified
72
tive test for suspected ischaemic conditions affecting the
as a pendular nystagmus, consisting of slow sinusoidal
brainstem. Obviously, the vestibulo-cochlear nerve can
oscillations, or as a jerk nystagmus, characterized by an
be involved in patients complaining of dizziness as well
alternating slow drift and a quick corrective phase. In the
as the anatomically closely related trigeminal and facial
latter type, a slow phase takes the eye away and a quick
nerves
. Optic neuropathy can be the result of multiple
10
corrective phase brings it back to the target
.
72
sclerosis, neurosyphilis, and vitamin B
deficiency. A
12
The clinician first observes for spontaneous nystagmus
depressed corneal reflex or a facial nerve palsy on the
by asking the patient to fix on a stationary target at a
same side as the ataxia can result from a cerebellopontine
distance of >2 meters
. A spontaneous nystagmus may
72
angle tumor. Lower brainstem disease can cause tongue
imply an acute peripheral vestibular lesion and, in this
or palate weakness, hoarseness, and dysphagia
. Some
69
case, occurs due to an imbalance in the tonic firing rate
pathologies cause dizziness in combination with hearing
of the vestibular neurons
. The spontaneous nystagmus
73
loss. Table 4 contains a sample CN examination
. Visual
70
following a lesion of the peripheral vestibular system is
a jerk nystagmus with the quick phase indicating the
unaffected side. In fact, the detectable eye movement
during spontaneous nystagmus is the quick phase toward
the unaffected ear
. In the acute phase, patients will
72,74
have difficulty reading and watching television. After
the acute episode, a patient can suppress the nystagmus
with visual fixation making it difficult for the examiner
to observe eye movements
. Preventing visual fixation
73
by using Frenzel glasses facilitates observation of a
spontaneous nystagmus: These glasses prevent light from
activating the smooth pursuit system, which can cancel
out the imbalance of the tonic firing rate produced by a
peripheral vestibular lesion
. A purely vertical (upbeat
74
or downbeat) or torsional spontaneous nystagmus is
indicative of a central vestibular lesion
. Nystagmus
9,72
due to a central lesion usually cannot be suppressed
with visual fixation
. A positional downbeat vertical
72,75
nystagmus occurs particularly in posterior fossa lesions
with Arnold-Chiari malformation as its most common
cause
. Nystagmus with one eye beating down and the
76,77
other upwards (skew nystagmus) has only been reported
in patients with Arnold-Chiari malformation
. A few
77
Fig. 3:
Fig. 3:
F
Fukuda step test
238 / The Journal of Manual & Manipulative Therapy, 2005
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