The examination of the central and peripheral nervous system,
like that of the heart, consists almost exclusively of tests
of function. Many of these tests require the cooperation of the
patient. However, the more urgent the need for a neurologic
exam, the less capable may the patient be to cooperate. The
extreme example is the comatose patient, whose life may depend
on prompt and accurate diagnosis but who cannot cooperate
at all. The basic neurologic examination is augmented
by special procedures as history and findings direct.
Neurologic exam reveals no gross sensory or motor deficits.
brain stem pons midbrain
Most part of the neurologic examination
are carried out on a regional basis and
interspersed with examinations of other
system. In analyzing and recording findings,
however, the physician classifieds
them according to anatomic and functional
divisions of the nervous system.
The central nervous system (CNS) comprises
the brain and spinal cord; the peripheral
nervous system, the cranial and
spinal nerves. Peripheral nerve fibers
are either motor (efferent) fibers carrying
impulses to muscles, or sensory (afferent)
fibers carrying impulses to the
spinal cord or brain stem. Both kinds of
fibers are often combined in a single
nerve trunk.
The physician tests sensory functions by
stimulating appropriate receptors and
noting the subject’ s responses. Motor
functions are tested by observing the
subject’s ability to perform certain actions.
Even in an unconscious patient,
testing the deep tendon reflexes enables
Physical Examination: Neurologic Examination
iTrans H & P 025
the examiner to assess the integrity of the spinal reflex
arcs, which consist of both sensory (stretch receptor)
and motor nerve fibers. But evaluation of
complex voluntary movements and muscle coordination
requires the conscious collaboration of the patient.
Assessment of cerebral functions (memory, orientation,
thinking capacity, mood) is described in the
next chapter.
If the patient is stuporous or unconscious, the physician
tries to determine the degree of central nervous
system depression by noting the size and reactivity
of the pupils, the rate and rhythm of breathing, the
response to noxious stimuli such as loud noises and
firm pressure over bony prominences, and the presence
of certain primitive reflexes such as the corneal and gag reflex. In the doll’s eye
maneuver, the examiner rotates the patient’s head from side to side and notes the
effect on eye position. Normally the eyes to rotate in a direction opposite to that in
which the head is moved, tending to maintain the same direction of gaze (oculocephalic
reflex). Failure of the eyes to rotate around their own vertical axes during this maneuver
indicates brain stem damage.
comatose, unconscious, unresponsive Glasgow coma score
postictal state catalepsy
corneal, gag reflex doll’s eye maneuver
The twelve pairs of cranial nerves emanate from the brain stem and pass to
structures in the head and neck. The first pair of cranial nerves (olfactory) are not
routinely tested but, as noted in chapter 21, the sense of smell can be evaluated by
asking the subject to identify common substances (soap, tobacco) by their odors.
The second pair (optic) are inspected during the
funduscopic examination and their function is
checked through vision testing. The third, fourth,
and sixth pairs (oculomotor, trochlear, and abducens)
control ocular movements. The fifth pair
(trigeminal) supply the face with motor and sensory
branches. They are tested by noting the
strength of jaw clenching and the sensitivity of
the facial skin in various areas to gentle pinprick.
The seventh pair (facial) innervate the muscles
of the face and are tested by having the patient
grimace, purse the lips, wrinkle the forehead, close
the eyes tightly, and so on. The sense of taste on
the anterior two- thirds of the tongue with a drop
of salt or sugar solution or vinegar. The eighth
pair (vestibulocochlear) are the nerves of hearPhysical
Examination: Neurologic Examination
iTrans H & P 025
ing and equilibrium. Testing the pharyngeal (gag) reflex
arc (as well as taste afferents from the posterior third of
the tongue), and the tenth (vagus), which carry the efferent
side. The vagus innervates the muscles of the soft
palate as well as those involved in swallowing and speech.
The eleventh pair (spinal accessory) sends motor fibers to
the sternocleidomastoid muscles at the side of the neck.
These are tested by having the subject rotate the head
against a resisting hand placed along side the chin. The
twelfth pair (hypoglossal) innervates the tongue and are
tested by assessing the patient’s ability to protrude the
tongue.
cranial nerves II through X II are intact.
bulbar, pseudobulbar palsy jaw jerk
Bell palsy Bell phenomenon
Horner syndrome Adie pupil
Argyll Robertson pupil Marcus Gunn pupil
The spinal nerves emerge from the spinal cord in pairs, one right, and one
left, and supply the body from the occiput downward with sensory and motor fibers.
A pair of spinal nerves is named from the vertebra
above which (cervical region) or below which (other
region) it emerges. Thus the L2 pair emerge below
the second lumbar vertebra. Sensory nerve
endings in the skin are distributed in segments
called dermatomes, each corresponding to a pair
of spinal nerves. Sensory and motor fibers to the
limbs pass through complicated systems of branching
and interconnection (branchial and lumbar plexuses)
before forming the main nerve trunks of the
upper and lower extremities. The entire skin surface
can be mapped as to the segmental origin of
its sensory supply, and like wise the spinal segment
or segments innervating each muscle are
known. With this anatomical knowledge in hand,
the physician can localize and characterize lesions of the spinal cord and peripheral
nerves by precise study of sensory and motor deficits. In addition, lesions of the
brain can be localized by their effect on coordination, stereognosis, and other complex
motor and sensory functions.
dermatome, segment peripheral neuropathy neuralgia, neuritis
radiculitis, radiculopathy focalizing, localizing signs
mononeuritis, polyneuritis
Physical Examination: Neurologic Examination
iTrans H & P 025
The examiner obtains some information about the motor system from the first view of
the patient, and gains more as the examination proceeds. Generalized weakness,
hemiparesis, disturbances of gait, posture, or speech, and abnormal movements such
as tics and tremors are readily observed. The orthopedic examination provides data
about muscle mass, strength, tone, and control. Paralyzed or disused muscles eventually
undergo contracture and atrophy. Paralysis due to peripheral (lower motor
neuron) disease is flaccid (muscles soft and limp). Paralysis due to a cerebral (upper
motor neuron) lesion is spastic (muscles tight, with rigid or jerky resistance to movement
by the examiner) because of uninterrupted, but no longer efficacious, postural
and checking signals from the basal ganglia of the brain.
akinesia, bradykinesia, dyskinesia akathisia
dystonia, hypotonia paresis, weakness
paralysis, palsy hemiparesis, hemiplegia
flaccid, spastic paralysis wrist drop, foot drop
decerebrate, decorticate posturing (rigidity)
rigidity: clasp-knife, cogwheel, lead-pipe, ratchet
gait: antalgic, apraxic, festinating. glue-footed, hemiplegic, hysterical,
propulsion, scissors, shuffling, spastic, steppage, Trendelenburg, waddling,
wide- based
Hoover test, sign tripod sign
moves all extremities well
In neurology, the term reflex refers to a muscular contraction in response to some
stimulus, such as tapping the patellar tendon. For a reflex to occur, both sensory and
motor limbs of the reflex arc must be intact. A deep tendon reflex, such as the
familiar knee jerk, is elicited by tapping the tendon smartly with a rubber reflex
hammer. For some tendons, such as that of the biceps brachii, the examiner may
place a thumb firmly over the tendon and then strike the thumb with the hammer.
This doesn’t feel very good but it vastly improves the accuracy of aim. The examiner
testes selected tendons (at a minimum, the biceps and triceps in the arm and the
patellar and calcaneal in the leg) and notes the quality and strength of responses,
comparing right and left. Normally a sudden stretch of a voluntary muscle tendon
elicits a prompt, brisk, transitory contraction of the muscle. In lower motor neuron
lesions the reflexes are reduced or absent. In upper motor neuron lesions the reflexes
are not only unimpaired but exaggerated. Besides deep tendon reflexes, superficial
or cutaneous reflexes yield information about peripheral sensory and motor
nerves. These include the abdominal and cremasteric reflexes. Abdominal reflexes,
elicited by stroking the relaxed abdomen, cause contraction of abdominal wall muscles,
with movement of the umbilicus toward the area stroked. The cremasteric reflexes
causes the testicle to draw up when the physician strokes the skin of the inner thigh.
DTR (deep tendon reflex) areflexia, hyperreflexia, hyporeflexia
reflex: Achilles, biceps, brachioradialis, patellar, quadriceps, triceps
ankle, knee jerk Jendrassik maneuver
abdominal, anal, cremasteric reflex root signs
Physical Examination: Neurologic Examination
iTrans H & P 025
Certain reflexes are seen only with upper motor neuron damage (pathologic reflexes).
These include the Babinski (upward deviation of the great toe on stroking the sole of
the foot), the Hoffman (twitching of the thumb when the middle finger is snapped),
and the palmomental (twitching of the chin on stimulation of the palm of the hand).
corticospinal, pyramidal, long tract signs pathologic reflex
patellar clonus, ankle clonus
Babinski, plantar reflex Babinski’s are downgoing, up going
Wartenberg reflex Hoffman reflex Chaddock reflex Oppenheim
reflex
Gordon reflex glabellar sign Myerson sign grasp reflex
Mayer reflex palmomental reflex
Motor coordination is tested by having the patient perform complex actions such as
touching the nose with the eyes closed, running one heel up and down the opposite
shin while recumbent, and making rapidly altering movements with both hands. In
the Gordon Holmes test, the patient is asked to pull with one fist against the physician’s
resistance in such a way that, if coordination is abnormal, the physician’s sudden
release of resistance will result in the fist striking the patient’s own face. (The physician,
however, prevents this.)
adiadochokinesis, dysdiadochokinesis ataxia, incoordination
heel- to- shin test finger- to- nose test
checking overshooting
decomposition of movement Stewart- (Gordon) Holmes sign
apraxia, dyspraxia dysmetria, dyssynergia
associated movements
Abnormal movements vary from fine, ineffectual twitches of a few muscle fibers (fasciculations)
to violent thrusting or hurling movements of the whole body. Tremors can
be coarse or fine, local or generalized; they may be worse at rest (resting tremor),
with purposeful movement (intention tremor), or with position- holding (postural
tremor). Asterixis is a coarse, flapping tremor that occurs when the patient attempts
to hold the hands steady with palms down. Chorea denotes sudden, brief, involuntary
jerking movements of the face or limbs; athetosis is a slow, continuous writhing.
Often these two occur together.
adventitious movements myoclonus myokymia
tetany carpopedal spasm
hemiballismus tic, twitch, habit spasm
chorea, athetosis fasciculation, fibrillation
Physical Examination: Neurologic Examination
iTrans H & P 025
The physician performs a basic sensory examination by noting the subject’s ability to
detect light touch (as from a soft brush or a wisp of cotton) and superficial pain (from
a gentle pinprick) over various parts of the body surface, always comparing right and
left. Nylon monofilaments of various calibers, which buckle at reproducible pressures,
can be used to quantify cutaneous sensory loss. Their principal application is in
grading diabetic neuropathy of the feet. Sensitivity to temperature can be tested by
applying cool and warm metal discs, or test tubes containing cool and warm water, to
the skin. Vibratory sense is tested by placing the shank of a vibrating tuning fork
against a superficially lying bone, such as a knuckle or shin. Proprioception is a form
of sensation by which the brain monitors the position and degree of stretch of voluntary
muscles in the trunk and limbs. It is important for both balance sense and coordination.
Proprioception can be tested by asking the patient to report the position in which
fingers or toes are placed by the examiner.
tactile, touch pain, temperature, and tactile
anesthesia, hyperesthesia, hyp(o)esthesia
10 g Semmes- Weinstein monofilament
glove, stocking anesthesia kinesthesia
pinprick, pinwheel vibratory sense
proprioception meralgia paresthetica
Other sensory modalities that
are tested in selected cases
are two- point discrimination
(the ability to distinguish two
adjacent, simultaneous
pinpricks), stereognosis (the
ability to identify objects
solely by feeling them), and
graphesthesia (the ability to
recognize letters or numbers
traced on the skin).
two- point discrimination barognosis
topognosis stereognosis graphesthesia
Meningitis (inflammation of the covering membranes of the brain and spinal cord) is
often accompanied by painful spasm of paraspinal and leg muscles.
Marked stiffness of the neck (nuchal rigidity) is a cardinal finding in meningitis. In
addition, two signs are often present. The Kernig sign is inability of the knee to be
extended when the hip is flexed, because of spasm. The Brudzinski sign is involuntary
flexion of the hips and knees when the neck is flexed by the examiner.
nuchal rigidity Kernig sign Brudzinski sign
Tetany, a hyperirritable state of the neuromuscular system, can be induced by various
drugs and metabolic states, particularly hypocalcemia. Signs of tetany are involuntary
muscle twitches and spasms, including carpopedal spasm and risus sardonicus,
and the Trousseau and Chvostek signs. The Chvostek sign is spastic contraction of
facial muscles induced by tapping over the facial nerve in front of the ear. The
Trousseau sign is spastic contraction of wrist and forearm muscles induced by inflation
of a sphygmomanometer cuff placed about the arm above systolic pressure.
neuromuscular irritability tetany
carpopedal spasm risus sardonicus
Chvostek sign Trousseau sign
Read more...
Posts
