Second edition

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of the body (from 2 to 4 mm at the fingertips to 20–30 mm
on the dorsum of the hand), what is most important here is
to compare both sides to look for a difference.
Agraphesthesia and diminished two-point discrimination
suggest a lesion in the parietal cortex; elementary sensory
loss, especially to pin-prick, is also seen with parietal
cortex lesions but in addition may occur with lesions of the
thalamus, brainstem, cord, or of the peripheral nerves.
Cerebellar testing
In addition to observing the patient’s gait for ataxia, as discussed
below, cerebellar testing also involves finger-tonose
and heel-to-knee-to-shin testing, testing for rapid
alternating movements and observing for dysarthria.
In the finger-to-nose test, patients are instructed to
keep their eyes open, extend the arm with the index finger
outstretched, and then to touch the nose with the index
finger. In the heel-to-knee-to-shin test, patients, while
seated or recumbent, are asked to bring the heel into contact
with the opposite knee and then to run that heel down
the shin below the knee. In both tests one observes for evidence
of dysmetria (as, for example, when the nose is
missed in the finger-to-nose test) and for intention tremor,
wherein, for example, there is an oscillation of the finger
and hand as it approaches the target (in this case the nose,
with this tremor worsening as the finger is brought progressively
closer to the nose).
Rapid alternating movements also assess cerebellar function.
Here, while seated, patients are asked to pronate the
hand and gently slap an underlying surface (e.g., a tabletop
or the patient’s own thigh) and then supinate the same hand
and again gently slap the underlying surface. Once they
have the hang of it, patients are then asked to repeat these
movements as quickly and carefully as possible. Decomposition
of this movement, known as dysdiadochokinesia, if
present, is generally readily apparent on this test.
Dysarthria may also represent cerebellar dysfunction
and may be casually assessed by simply listening carefully
to the patient’s spontaneous speech, noting any evidence of
slurring. In doubtful cases one may ask the patient to
repeat a test phrase, such as ‘Methodist Episcopal’ or ‘Third
Riding Artillery Brigade’ (DeJong 1979). Importantly,
dysarthria may also be seen with lesions of the motor cortex
or associated subcortical structures.
Station, gait, and the Romberg test
Station is assessed by asking patients to stand with their
feet normally spaced, and observing for any sway or loss of
balance. At this point, if station is adequate, one should
perform the Romberg test by telling patients that you will
ask them to put their feet close together, as if ‘at attention’,
and then to close their eyes, reassuring them that you will
have your hands close by and that you will not let them fall.
1.3 Neurologic examination 13
If they are comfortable with these instructions then the test
can be carried out, observing the patients for perhaps half a
minute to see whether or not any swaying develops once
the eyes are closed. A ‘positive’ Romberg test indicates a
loss of position sense, as may be seen with a peripheral
neuropathy or damage to the posterior columns.
Gait is tested by asking the patient to walk a straight
line down a hall, then walking ‘heel to toe’ in a tandem
walk, and, finally, if these are done adequately, by
asking the patient to walk ‘on the outside of your feet, like
a “cowboy”’.
An ataxic gait, seen in cerebellar disorders, is wide based
and staggering: steps are irregular in length, the feet are
often raised high and brought down with force, and the
overall course is zigzagging. In a ‘magnetic’ gait, as seen in
hydrocephalus or bilateral frontal lesions, the feet seem
stuck to the floor as if magnetized or glued to it. In a steppage
gait, seen in peripheral neuropathies, the normal dorsiflexion
of the feet with walking is lost and patients raise
their feet high to avoid tripping on their toes. In a spastic
gait, seen with hemiplegic patients, the affected lower
extremity is rigid in extension and the foot is plantar
flexed: with each step, the leg is circumducted around and
the front of the foot is often scraped along the floor. In very
mild cases of hemiplegia, the gait, to casual inspection, may
not be abnormal; however, when patients walk ‘on the outside’
of their feet, one often sees dystonic posturing of the
upper extremity on the involved side. Parkinsonian gait is
described in Abnormal movements, p. 14.
Strength
Strength may, according to Brain (1964), be graded as
follows: 0, no contraction; 1�, a flicker or trace of movement;
2�, active movement providing that gravity is eliminated;
3�, active movement against gravity; 4�, active
movement against some resistance; and 5�, full strength.
In the process of assessing muscular strength one should
also observe for any atrophy, fasciculations, or myotonia.
Myotonia is sometimes apparent in a handshake, as
patients may have trouble relaxing their grip, and may also
be assessed by using a reflex hammer to lightly tap a muscle
belly, such as at the thenar eminence, and watching for
distinctive myotonic dimpling.
Common patterns of weakness include monoparesis, if
only one limb is involved, hemiparesis if both limbs on one
side are weak, paraparesis if both lower extremities are
weak, and quadriparesis (or, alternatively, tetraparesis), if
all four extremities are weakened. In cases when strength � 0
then one speaks not of paresis but of paralysis, and uses the
terms monoplegia, hemiplegia, paraplegia, or quadriplegia.
When weakness is present, note should be made
whether the proximal or distal portions of the limb are primarily
involved; in cases of hemiparesis in which both
limbs are not equally affected, the limb that is more
affected should be noted.