General Outline of the Neurologic Examination

The neurologic examination, as commonly done, includes the major categories listed in Table 4.1.
Although the examination does not have to be performed in any
particular sequence, and every physician develops his own routine for
the examination, it is customary to record the neurologic examination
in the general format outlined in Table 4.1, or with minor modifications.

The complete neurologic examination can be a complex and
arduous undertaking. In fact, few neurologists do a truly complete exam
on every patient. As with the general physical examination, the history
focuses the neurologic examination so that certain aspects are
emphasized in a given clinical situation. The exam done on a typical
patient with headache is not the same as that done on a patient with
low back pain, or dementia, or cerebrovascular disease. The examination
should also be adapted for the circumstances. If the patient is in pain
or apprehensive, it may initially focus on the area of complaint,
followed later by a more thorough assessment. Only a brief examination
may be possible for unstable or severely ill persons until their
condition stabilizes. With comatose, combative or uncooperative
patients, a compulsively complete examination is an impossibility.
However, in each of these situations at least some maneuvers are
employed to screen for neurologic dysfunction that is not necessarily
suggested by the history. A rapid “screening” or “mini” neurologic
examination may initially be adequate for persons with minor or
intermittent symptoms. Every patient does not require every conceivable
test, but all require a screening examination. The findings on such a
screening examination determine the emphasis of a more searching
subsequent examination. There are a number of ways to perform a
screening examination. Table 4.2 details such an abbreviated examination from DeJong’s The Neurologic Examination.

There are two basic ways to do a traditional neurologic
examination, regional and systemic. A system approach evaluates the
motor system, then the sensory system, and so on. A regional approach
evaluates all the systems in a given region, such as the upper
extremities, then the lower extremities. The screening exam outlined in
Table 4.3 is an amalgam of the regional and
system approaches geared for speed and efficiency. The concept is an
examination that requires the nervous system to perform at a high
level, relying heavily on sensitive signs, especially the flawless
execution of complex functions. If the nervous system can perform a
complex task perfectly, it is very unlikely there is significant
pathology present, and going through a more extensive evaluation is not
likely to prove productive. A neurologic examination that assesses
complex functions and seeks signs that are sensitive indicators of
pathology is efficient and not overly time consuming.

The examination begins with taking the medical history,
which serves as a fair barometer of the mental status. Patients who can
relate a logical, coherent, pertinent, and sensible narrative of

their
problem will seldom have abnormalities on more formal bedside mental
status testing. On the other hand, a rambling, disjointed, incomplete
history may be a clue to the presence of some cognitive impairment,
even though there is no direct complaint of thinking or memory problems
from the patient or the family. Similarly, psychiatric disease is
sometimes betrayed by the patient’s demeanor and style of history
giving. If there is any suggestion of abnormality from the interaction
with the patient during the history taking phase of the encounter, then
a more detailed mental status examination should be carried out. Other
reasons to do a formal mental status examination are discussed in Chapter 5.
Simple observation is often useful. The patient’s gait, voice,
mannerisms, ability to dress and undress, and even handshake (grip
myotonia) may suggest the diagnosis.

The Table 4.3 screening
examination continues by doing everything that requires use of a
penlight. Begin by noting the position of the eyelids and the width of
the palpebral fissures bilaterally. Check the pupils for light reaction
with the patient fixing at distance. If the pupillary light reaction is
normal and equal in both eyes, checking the pupillary near reaction is
not necessary. Continue by assessing extraocular movements in the six
cardinal positions of gaze, having the patient follow the penlight. Be
sure the patient has no diplopia or limitation of movement, and that
ocular pursuit movements are smooth and fluid. With the eyes in primary
and eccentric positions, look for any nystagmus. The eye examination is
discussed in more detail in Chapters 9 and 10.
With the light still in hand, prepare to examine the pharynx and oral
cavity. Examination of trigeminal motor function is accomplished merely
by watching the patient’s jaw drop open prior to examining the mouth

and
throat. When the pterygoids are unilaterally weak, the jaw invariably
deviates toward the weak side on opening. This deviation, while subtle,
is a sensitive indicator of trigeminal motor root pathology. Observe
the tongue for atrophy or fasciculations. Have the patient phonate and
be sure the median raphe of the palate elevates in the midline. There
is little to be gained by checking the gag reflex if the patient has no
complaints of dysphagia or dysarthria and there is no reason from the
history to suspect a brainstem or cranial nerve lesion. Routine
elicitation of the gag reflex is rarely informative and is unpleasant
for the patient. Have the patient protrude the tongue and move it from
side to side.

Functions requiring the use of the penlight completed,
observe the nasolabial folds for depth and symmetry and compare the
forehead wrinkles on both sides. Then have the patient grimace,
vigorously baring the teeth, while closing the eyes tightly. Note the
symmetry of the grimace, how many teeth are seen on each side, and the
relative amplitude and velocity of the lower facial contraction, as
well as the symmetry of the upper facial contraction. How completely
the patient buries the eyelashes on the two sides is a sensitive
indicator of orbicularis oculi strength.

If the patient has no complaints of hearing loss,
tinnitus, vertigo, facial numbness or weakness and there is no specific
reason suggested by the history to do so, routine examination of
hearing is seldom productive. Examination of hearing is discussed
further in Chapter 13. Complete the cranial nerve examination by checking the visual fields and fundi.

Screening examination of motor function, sensory
function, and coordination in the upper extremities can be completed as
one compound, multifaceted maneuver. In most clinical situations in
which a screening examination is appropriate, the primary concern is to
detect a lesion involving the corticospinal tract (CST). The CST
preferentially innervates certain muscle groups, and these are the
groups most likely to be weak because of an upper motor neuron lesion.
In the upper extremity the CST innervated muscles are the finger
extensors, wrist extensors, forearm supinators, external rotators of
the shoulder, triceps, and deltoid. The cardinal CST muscles in the
lower extremity are the hip flexors, the hamstrings, and the
dorsiflexors of the foot and toes. In addition, one of the most
important functions of the CST is to provide fine motor control to
distal muscles. Fine motor control, including rapid alternating
movements, would furthermore be impossible without normal cerebellar
function. The screening examination focuses on detecting weakness in
the CST distribution and impaired distal fine motor control. In the
upper extremity, the best muscles for strength testing are the deltoid,
triceps, wrist and finger extensors, and intrinsic hand muscles,
especially the interossei. Although commonly done, it is very poor
technique to use grip power to assess strength. The finger and wrist
flexors are not corticospinal innervated, and are not likely to be weak
with a mild corticospinal tract lesion. In addition, grip is a complex
function with many different muscles involved, so it is insensitive to
peripheral pathology as well. Although strength is the primary focus of
the motor examination, it is important to note any changes in muscle
bulk, e.g., atrophy, hypertrophy, or pseudohypertrophy; or muscle tone,
e.g., rigidity, spasticity, or hypotonia; and to note any abnormal
involuntary movements, e.g., tremor, fasciculations, or chorea.

When patients with mild CST lesions retain normal
strength, ancillary maneuvers may detect the deficit. The most
important of these is the examination for pronator drift. With the
patient’s upper extremities outstretched to the front, palms up, and
with the eyes closed, observe the position of each extremity. Normally,
the palms will remain flat, the elbows straight and the limbs
horizontal. With a CST lesion, the strong muscles are the pronators,
the biceps, and the internal rotators of the shoulder. As these
overcome the weakened CST innervated muscles, the hand pronates, the
elbow flexes, and the arm drifts downward.

A screening sensory examination assesses sensory
function by tasking the nervous system with performing a complex and
difficult function. If this function is executed flawlessly, the
likelihood of finding clinically significant sensory loss through a
more detailed examination is low. Testing for stereognosis and
performing double simultaneous stimulation are efficient and sensitive
screening tools. The period of time waiting for pronator drift to occur
is a convenient time to begin examining upper extremity sensory
functions. While the patient is still in “drift position”—arms
outstretched in front, palms up, and eyes closed, ask him to indicate
which side is touched, then lightly touch first one hand, then the
other, then both, using minimal finger pressure, a cotton wisp, or a
tissue. A set of stimuli to the lower extremities is also convenient at
this point. Continue by testing for stereognosis. Place an object, such
as a coin, a key, a safety pin, or a paper clip, into one of the
patient’s still upturned palms, and ask him to feel and identify it.
Stereognosis is the ability to recognize and identify an object by
feel; the inability to do so is astereognosis. Stereognosis can only be
normal when all the peripheral sensory pathways and the parietal lobe
association areas are intact; only when the primary sensory modalities
are normal does astereognosis indicate a parietal lobe lesion. A
patient with severe carpal tunnel syndrome and numb fingers may not be
able to identify a small object by feel; this finding is NOT
astereognosis. As a screening test, stereognosis is an excellent
modality because it tests the entire sensory pathway, from the
fingertips to the parietal lobe. If stereognosis is rapid and accurate,
then all the sensory pathways must be functioning normally and detailed
examination is not likely to be productive. If a deficit is found on
this preliminary assessment, a detailed examination of sensory function
is necessary to localize the site of the abnormality. Additional useful
information can be gained by dropping the small stereognosis object
more or less in the center of the palm. A patient with normal fine
motor control will adroitly manipulate the object, move it to the
fingertips, rub it between the thumb and opposed fingers, and announce
the result. A patient with a

mild
corticospinal lesion, producing relatively subtle clinical signs
without major weakness, may be clumsy in manipulating the object, and
will occasionally drop it.

After testing double simultaneous stimulation and
stereognosis, with the patient’s eyes still closed, the hand and arm
position is examined to determine if any drift has occurred. Then, eyes
still closed, the patient is instructed to spread the fingers, then
touch first one index finger and then the other to the tip of his nose.
This is the finger-to-nose (FTN) test, which is used to look for
intention tremor, incoordination, and past-pointing. Ordinarily, the
FTN test is carried out with the patient’s eyes open. For purposes of
the screening exam, the more difficult maneuver of eyes closed FTN is
performed first. If it is done perfectly, then neither cerebellar nor
vestibular disease is likely. Complete the upper extremity examination
by examining forearm roll, finger roll, and rapid alternating movements.

After completing examination of motor, sensory, and
cerebellar function in the upper extremities, attention is turned to
strength assessment of the lower extremities. The important muscles to
examine are the CST innervated groups: hip flexors, knee flexors, and
the dorsiflexors of the foot. Further sensory testing is convenient at
this point, comparing primary modality sensibility on the two sides,
comparing proximal to distal in the lower extremities if peripheral
neuropathy is a diagnostic consideration, and examining vibratory
sensation over the great toes.

Continue by eliciting the biceps, triceps,
brachioradialis, knee, and ankle reflexes, then assess the plantar
responses. Conclude the examination by checking station and gait.
Excellent tests for gait and balance functions are tandem walking with
eyes closed and hopping on either foot.

The rest of this book is devoted to the detailed assessment of the functions touched on in the screening examination.