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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_6032_Библиотеки_им_академика_М_И_Перельмана
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neurologic symptoms that were later determined to be early symptoms of
amyotrophic lateral sclerosis.
4,5
Table 1
If a patient is suspected of having myelopathy, he or she may be initially
evaluated from behind, with the examiner looking for a wide-based gait (the
feet farther apart than a normal distance of 2 to 4 inches) and the trunk
showing excessive lateral sway. Formal gait analysis has shown that patients
with more advanced disease will have increased stance width, decreased
stride length, and increased time spent in the stance phase.
6
In a patient with myelopathy, the upper extremities may demonstrate
normal, diminished, or brisk reflexes depending on the level of spinal cord
compression. If the exiting nerve root at the stenotic level also is compressed,
the corresponding reflex may be diminished (for example, C6-7 stenosis may
compress the exiting C7 nerve root and cause an absent or diminished triceps
reflex). Spinal levels below the compression will be disinhibited and, thus,
patellar and Achilles reflexes are typically hyperreflexic and symmetric.
Sharply dorsiflexing the foot with continued pressure will place a stretch on
the gastrocnemius muscle-tendon unit and may elicit ankle clonus, which
further confirms an upper motor neuron pathology.
The examiner also should test for the presence of pathologic reflexes.
Withdrawal of the lower extremity from a painful stimulus is a primitive
reflex present at birth. Between 12 and 24 months of age, the motor cortex
develops and maintains suppression of this flexion reflex. The reappearance
of the reflex typically signifies organic interference in one of the upper motor
neuron pathways.7 Several different methods, including the Babinski,
Chaddock, and Oppenheim methods, can be used to test for a pathologic
flexion reflex.7 The Hoffmann reflex is flexion of the thumb that is elicited
by flicking the distal phalanx of the long or middle finger; this reflex may be
seen in patients with myelopathy. The Hoffmann reflex is thought to be
caused by hyperreflexia of the finger flexors, not by the presence of a
pathologic reflex.
7
Impaired hand coordination is a common symptom of myelopathy. Hand
dexterity can be tested by asking the patient to grip and release his or her
hand as many times as possible in 15 seconds. In an individual without
myelopathy, this task normally can be performed 25 to 30 times in 15
seconds; however, a patient with myelopathy will exhibit substantial
impairment in the ability to perform the test. After surgical decompression,
substantial improvement can be seen.
8
If a patient reports bowel or bladder dysfunction or reduced sensation in
the saddle area, an assessment of rectal tone and perianal and saddle
sensation should be performed. Urgent care is needed if there is suspicion of
cauda equina syndrome.9 Substantial sphincter dysfunction has been
described as a predictor of a poor clinical outcome.
10
Unilateral Symptoms
Symptoms of weakness, numbness, or pain in a single extremity should lead
the examiner to consider the possibility of nerve root impairment. Included in
this differential diagnosis are traumatic and entrapment injuries of the
brachial or lumbosacral plexus and their associated peripheral nerves. In the
cervical spine, the strength examination should include the C5 to T1
myotomes. In the lumbar spine, the L2 to S1 myotomes should be examined.
If a specific muscle demonstrates focal weakness, further manual muscle
testing may elucidate whether the entrapment site is at the nerve root level or
Figure 1
more peripheral. Weakness with abduction of the fingers can be seen in both
C8 radiculopathy and peripheral ulnar nerve entrapment. With further
examination of index finger extension and thumb abduction, the examiner
can determine whether the entrapment most likely lies at the C8 level or is
more distally located in the ulnar nerve. The extensor indices and abductor
pollicis brevis both have C8 contributions, but they are supplied by the radial
and median nerves, respectively (Figure 1). Similarly, if findings of
weakness with ankle dorsiflexion and/or great toe extension are present,
weakness with hip abduction can be expected if the entrapment is at the L5
nerve root level (Figure 2).
Clinical photographs showing C8 distribution manual
muscle testing. With C8 motor involvement, all three
muscles are weak. Weakness isolated to only one test suggests a
more peripheral nerve entrapment site. A, Ulnar nerve–finger
abduction. B, Median nerve–thumb abduction. C, Radial nerve–index
finger extension.
Figure 2
Clinical photographs showing L5 distribution weakness
testing. With L5 motor involvement, both muscles are weak.
Weakness isolated to only one test suggests a more peripheral nerve
entrapment site. A, Peroneal nerve–great toe extension. Weakness
can be seen with L5 radiculopathy or peroneal nerve entrapment B,
Superior gluteal nerve–hip abduction. Weakness with hip abduction
and great toe extension is consistent with L5 radiculopathy.
The sensory examination should look for sensory abnormalities in the
distribution of a particular dermatome or the peripheral nerves. Many
dermatomal maps exist with variations among them, which may make it
difficult to determine sensory impairment at a specific nerve root level.
Several factors can contribute to difficulty in identifying the nerve root level
of the impairment, including the connections between nerve roots, the
transmission of sensory modalities to the same area of skin by different nerve
roots, and the substantial overlap between dermatomes.11 Because of the
substantial overlap of corresponding dermatomes, it is rare for entrapment of
a single nerve root to cause dense numbness. Rather, the numbness is usually
vague and poorly defined. An area of dense numbness should lead to a more
rigorous examination for peripheral nerve entrapment or more widespread
peripheral neuropathy.
Table 2
Muscle stretch reflexes of the upper and lower extremities should be
assessed for an asymmetric diminished or an absent reflex, which would
suggest nerve root impingement. Table 2 lists specific reflexes and their
corresponding innervations. The pronator teres reflex and medial hamstring
reflex are less commonly evaluated but can be clinically useful. To elicit the
pronator reflex, the forearm is held in a neutral position with the elbow flexed
to 90° and resting in the patient’s lap. The examiner then taps the volar
portion of the distal radius; this forces the arm into a supinated position and
places a stretch on the pronator teres muscle and normally elicits a reflexive
motion of pronation12 (Figure 3). The medial hamstring reflex is most easily
elicited with the patient prone, with the ankle of the leg being tested crossed
over the opposite ankle (Figure 4). The reflex is typically more difficult to
elicit than the patellar and Achilles reflexes; however, the presence of
asymmetry can provide useful diagnostic information.
Pain Symptoms
Important clues that aid in the diagnosis of a disorder and the determination
of appropriate treatment can be gained by observing the patient’s gait and
posture. If the patient lurches off to the side during ambulation, it is necessary
to determine if the gait is antalgic or has a Trendelenburg pattern. A patient
Figure 3
with an antalgic gait will lurch toward the painful side during weight bearing
on the affected limb to decrease the pull of painful hip abductors. A patient
with a Trendelenburg (or gluteus medius) gait has weak hip abductors. When
the affected side is in stance phase, the contralateral hip will drop (sound-side
sag). With a compensated Trendelenburg gait, the patient will list the trunk
over the weak side to maintain his or her center of gravity.
Clinical photograph shows testing of the pronator reflex.
The patient’s forearm is placed in a neutral position with the
elbow flexed to 90°. The examiner then taps the volar portion of the
distal radius, forcing the arm into a supinated position, which places a
stretch on the pronator teres muscle. This normally elicits a reflexive
motion of pronation.
Observation of the patient in the examination room can yield information
about postures or habits that may be contributing to tissue overload. In the
patient with a head-forward posture and rounded shoulders, tissue overload
can be expected in the upper trapezius or rhomboids, with associated pain and
tenderness in this region. After assessing posture, the examiner can select a
few muscles for palpation to look for confirmatory tenderness and tautness.
When palpating selected muscles, it is helpful to ask the patient if there is any
Figure 4
radiating pain and if his or her typical pain is being reproduced. Positive
findings are suggestive of myofascial pain.
In acute conditions, the patient may adopt positions that help offload
painful structures. In the presence of cervical radiculopathy or brachial
plexopathy, the patient may rest the hand of the affected upper extremity on
top of his or her head to alleviate tension on the affected nerves. The
examiner may notice the patient in this position (Bakody sign) or may request
that the patient adopt this position and then ask if there is pain relief
(shoulder abduction test)
13,14
(Figure 5). A lateral shift of the lumbar spine
correlates highly with the presence of an acute disk herniation. Most
commonly, the patient’s body will be shifted to the side that is contralateral
from the herniation.
15
Clinical photograph shows testing of the medial hamstring
reflex. The patient is prone, with the ankle of the leg being
tested crossed over the opposite ankle. Tapping the medial hamstring
tendon normally elicits a palpable or visible contraction of the medial
hamstring.
Standing behind the patient, the examiner can look for and palpate
asymmetries of the paraspinal muscles, scapula, rib cage, iliac crest, and
greater trochanters that may signify a scoliotic deformity. Lack of alignment
of the cervicothoracic junction to the gluteal cleft suggests coronal plane
decompensation.
16
During the thoracic and lumbar examination, forward bending should be
assessed by observing the patient from the side. Forward bending is a
combination of thoracic, lumbar, and hip flexion. In assessing movement
impairments that may be contributing to a painful condition, it is important to
note the relative contribution of each of these areas. Normally, the forward
bending motion is initiated with a posterior sway of the hips. The lumbar
spine then reverses its normal curvature and ends in a flattened position.
17
In patients with low back pain, repetitive end-range flexion and extension
and side-gliding/rotation can be performed to determine if the pain has a
directional preference (ie, whether the pain lessens with repetitive end-range
movements in a particular direction). In patients demonstrating a directional
preference, matching the patient’s directional preference to a physical therapy
program that uses the favored direction has been shown to provide a better
outcome than therapy programs that do not use a directional preference.
18,19
Figure 5
Clinical photograph of a patient exhibiting the Bakody sign.
By placing her hand on top of her head, this patient lessens
tension on the cervical nerve roots, which decreases pain in her right
extremity.
In the patient with radiating pain, a provocative test may be used to help
determine if the pain is caused by radiculopathy. The Spurling test is
performed by tilting the patient’s head toward the painful side to see if this
elicits reproduction of the patient’s typical cervical radicular symptoms. If
needed, pressure then can be placed on top of the patient’s head in a further
attempt to elicit symptoms. The test has a higher level of specificity (92% to
100%) than sensitivity (40% to 60%).
20
Pain radiating into the extremity is an indication for performing a dural
stretch test. Reproduction of radiating extremity pain is considered a sign of
possible radiculopathy. Classically, this test is performed in the lower
extremity by putting tension on the L5 and S1 nerve roots via a straight leg
raise test with the patient supine. The test also can be performed in the seated
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