There are various ways to perform a neurological examination. The quickest information
pertinent to the diving injury is obtained by directing the initial
examination toward the symptomatic areas of the body. These concentrate on the
motor, sensory, and coordination functions. If this examination is normal, the most
productive information is obtained by performing a complete examination of the
following:
- Mental status
- Coordination
- Motor
- Cranial nerves
- Extremity strength
- Sensory
- Deep tendon reflexes
The following procedures are adequate for preliminary examination. Figure 5A-1a
can be used to record the results of the examination.
A diver with decompression sickness may experience disturbances in the
muscle system. The range of symptoms can be from a mild twitching of a muscle
to weakness and paralysis. No matter how slight the abnormality, symptoms
involving the motor system shall be treated.
These muscles are tested with resistance provided by the
examiner. The patient should overcome force applied by the examiner that is
tailored to the patient’s strength. Table 5A-1 describes the extremity strength tests.
The six muscle groups tested in the upper extremity are:
- Deltoids.
- Latissimus.
- Biceps.
- Triceps.
- Forearm muscles.
- Hand muscles.
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Table 5A-1. Extremity Strength Tests.
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The lower extremity strength is assessed by watching the
patient walk on his heels for a short distance and then on his toes. The patient
should then walk while squatting (“duck walk”). These tests adequately assess
lower extremity strength, as well as balance and coordination. If a more detailed
examination of the lower extremity strength is desired, testing should be accomplished
at each joint as in the upper arm.
Muscles are visually inspected and felt, while at rest, for size and
consistency. Look for symmetry of posture and of muscle contours and outlines.
Examine for fine muscle twitching.
Feel the muscles at rest and the resistance to passive movement.
Look and feel for abnormalities in tone such as spasticity, rigidity, or no tone.
Inspection may reveal slow, irregular, and jerky movements,
rapid contractions, tics, or tremors.
Common presentations of decompression sickness in a diver
that may indicate spinal cord dysfunction are:
- Pain
- Numbness
- Tingling (“pins-and-needles” feeling; also called paresthesia)
An examination of the patient’s sensory faculties should
be performed. Figure 5A-2a shows the dermatomal (sensory) areas of skin sensations
that correlate with each spinal cord segment. Note that the dermatomal areas
of the trunk run in a circular pattern around the trunk. The dermatomal areas in the
arms and legs run in a more lengthwise pattern. In a complete examination, each
spinal segment should be checked for loss of sensation.
Figure 5A-2a. Dermatomal Areas Correlated to Spinal Cord Segment (sheet 1 of 2).
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ASensations easily recognized by most normal people are sharp/dull
discrimination (to perceive as separate) and light touch. It is possible to test pressure,
temperature, and vibration in special cases. The likelihood of DCS affecting
only one sense, however, is very small.
An ideal instrument for testing changes in sensation is a sharp
object, such as the Wartenberg pinwheel or a common safety pin. Either of these
objects must applied at intervals. Avoid scratching or penetrating the skin. It is not
the intent of this test to cause pain.
Move the pinwheel or other sharp object from the top of the
shoulder slowly down the front of the torso to the groin area. Another method is to
run it down the rear of the torso to just below the buttocks. The patient should be
asked if he feels a sharp point and if he felt it all the time. Test each dermatome by
going down the trunk on each side of the body. Test the neck area in similar
fashion.
In testing the limbs, a circular pattern of testing is best. Test each
limb in at least three locations, and note any difference in sensation on each side of
the body. On the arms, circle the arm at the deltoid, just below the elbow, and at
the wrist. In testing the legs, circle the upper thigh, just below the knee, and the
ankle.
The hand is tested by running the sharp object across the back
and palm of the hand and then across the fingertips.
If an area of abnormality is found, mark the area as a
reference point in assessment. Some examiners use a marking pen to trace the area
of decreased or increased sensation on the patient’s body. During treatment, these
areas are rechecked to determine whether the area is improving. An example of
improvement is an area of numbness getting smaller.
The purpose of the deep tendon reflexes is to determine if
the patient’s response is normal, nonexistent, hypoactive (deficient), or hyperactive
(excessive). The patient’s response should be compared to responses the
examiner has observed before. Notation should be made of whether the responses
are equal bilaterally (both sides) and if the upper and lower reflexes are similar. If
any difference in the reflexes is noticed, the patient should be asked if there is a prior medical condition or injury that would cause the difference. Isolated differences
should not be treated, because it is extremely difficult to get symmetrical
responses bilaterally. To get the best response, strike each tendon with an equal,
light force, and with sharp, quick taps. Usually, if a deep tendon reflex is abnormal
due to decompression sickness, there will be other abnormal signs present. Test
the biceps, triceps, knee, and ankle reflexes by striking the tendon as described in
Table 5A-2.
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Table 5A-2. Reflexes.
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