APPENDIX 5A — Neurological Examination 5A-1
This appendix provides guidance on evaluating diving accidents prior to treat-
ment. Figure 5A-1a is a guide aimed at non-medical personnel for recording
essential details and conducting a neurological examination. Copies of this form
should be readily available. While its use is not mandatory, it provides a useful aid
for gathering information.
When using the form in Figure 5A-1a, the initial assessment must gather the
necessary information for proper evaluation of the accident.
When a diver reports with a medical complaint, a history of the case shall be
compiled. This history should include facts ranging from the dive profile to
progression of the medical problem. If available, review the divers Health Record
and completed Diving Chart or Diving Log to aid in the examination. A few key
questions can help determine a preliminary diagnosis and any immediate treat-
ment needed. If the preliminary diagnosis shows the need for immediate
recompression, proceed with recompression. Complete the examination when the
patient stabilizes at treatment depth. Typical questions should include the
What is the problem/symptom? If the only symptom is pain:
Describe the pain:
Is the pain localized, or hard to pinpoint?
Has the patient made a dive recently?
What was the dive profile?
What was the depth of the dive?
What was the bottom time?
What dive rig was used?
What type of work was performed?
Did anything unusual occur during the dive?
5A-2 U.S. Navy Diving Manual—Volume 5
How many dives has the patient made in the last 24 hours?
Chart profile(s) of any other dive(s).
Were the symptoms first noted before, during. or after the dive? If after the
dive, how long after surfacing?
If during the dive, did the patient notice the symptom while descending, on the
bottom, or during ascent?
Has the symptom either increased or decreased in intensity since first noticed?
Have any additional symptoms developed since the first one?
Has the patient ever had a similar symptom?
Has the patient ever suffered from decompression sickness or gas embolism in
the past?
Describe this symptom in relation to the prior incident if applicable.
Does the patient have any concurrent medical conditions that might explain
the symptoms?
To aid in the evaluation, review the divers Health Record, including a baseline
neurological examination, if available, and completed Diving Chart or Diving
Log, if they are readily available.
There are various ways to perform a neurological examination. The quickest infor-
mation 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
Mental status
Cranial nerves
Extremity strength
Deep tendon reflexes
The following procedures are adequate for preliminary examination. Figure 5A-1a
can be used to record the results of the examination.
APPENDIX 5A — Neurological Examination 5A-3
Figure 5A-1a.
Neurological Examination Checklist (sheet 1 of 2).
5A-4 U.S. Navy Diving Manual—Volume 5
Figure 5A-1b.
Neurological Examination Checklist (sheet 1 of 2).
APPENDIX 5A — Neurological Examination 5A-5
Mental Status.
This is best determined when you first see the patient and is char-
acterized by his alertness, orientation, and thought process. Obtain a good history,
including the dive profile, present symptoms, and how these symptoms have
changed since onset. The patients response to this questioning and that during the
neurological examination will give you a great deal of information about his
mental status. It is important to determine if the patient knows the time and place,
and can recognize familiar people and understands what is happening. Is the
patients mood appropriate?
Next the examiner may determine if the patient’s memory is intact by questioning
the patient. The questions asked should be reasonable, and you must know the
answer to the questions you ask. Questions such as the following may be helpful:
What is your commanding officers name?
What did you have for lunch?
Finally, if a problem does arise in the mental status evaluation, the examiner may
choose to assess the patient’s cognitive function more fully. Cognitive function is
an intellectual process by which one becomes aware of, perceives, or compre-
hends ideas and involves all aspects of perception, thinking, reasoning, and
remembering. Some suggested methods of assessing this function are:
The patient should be asked to remember something. An example would be
“red ball, green tree, and couch.” Inform him that later in the examination you
will ask him to repeat this information.
The patient should be asked to spell a word, such as “world,” backwards.
The patient should be asked to count backwards from 100 by sevens.
The patient should be asked to recall the information he was asked to
remember at the end of the examination.
Coordination (Cerebellar/Inner Ear Function).
A good indicator of muscle
strength and general coordination is to observe how the patient walks. A normal
gait indicates that many muscle groups and general brain functions are normal.
More thorough examination involves testing that concentrates on the brain and
inner ear. In conducting these tests, both sides of the body shall be tested and the
results shall be compared. These tests include:
1. Heel-to-Toe Test
. The tandem walk is the standard “drunk driver” test. While
looking straight ahead, the patient must walk a straight line, placing the heel of
one foot directly in front of the toes of the opposite foot. Signs to look for and
consider deficits include:
Does the patient limp?
Does the patient stagger or fall to one side?
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2. Romberg Test
. With eyes closed, the patient stands with feet together and
arms extended to the front, palms up. Note whether the patient can maintain
his balance or if he immediately falls to one side. Some examiners recommend
giving the patient a small shove from either side with the fingertips.
3. Finger-to-Nose Test
. The patient stands with eyes closed and head back, arms
extended to the side. Bending the arm at the elbow, the patient touches his
nose with an extended forefinger, alternating arms. An extension of this test is
to have the patient, with eyes open, alternately touch his nose with his
fingertip and then touch the fingertip of the examiner. The examiner will
change the position of his fingertip each time the patient touches his nose. In
this version, speed is not important, but accuracy is.
4. Heel-Shin Slide Test
. While standing, the patient touches the heel of one foot
to the knee of the opposite leg, foot pointing forward. While maintaining this
contact, he runs his heel down the shin to the ankle. Each leg should be tested.
5. Rapid Alternating Movement Test
. The patient slaps one hand on the palm of
the other, alternating palm up and then palm down. Any exercise requiring
rapidly changing movement, however, will suffice. Again, both sides should
be tested.
Cranial Nerves.
The cranial nerves are the 12 pairs of nerves emerging from the
cranial cavity through various openings in the skull. Beginning with the most ante-
rior (front) on the brain stem, they are appointed Roman numerals. An isolated
cranial nerve lesion is an unusual finding in decompression sickness or gas embo-
lism, but deficits occasionally occur and you should test for abnormalities. The
cranial nerves must be quickly assessed as follows:
I. Olfactory
. The olfactory nerve, which provides our sense of smell, is usually
not tested.
II. Optic
. The optic nerve is for vision. It functions in the recognition of light and
shade and in the perception of objects. This test should be completed one eye
at a time to determine whether the patient can read. Ask the patient if he has
any blurring of vision, loss of vision, spots in the visual field, or peripheral
vision loss (tunnel vision). More detailed testing can be done by standing in
front of the patient and asking him to cover one eye and look straight at you. In
a plane midway between yourself and the patient, slowly bring your fingertip
in turn from above, below, to the right, and to the left of the direction of gaze
until the patient can see it. Compare this with the earliest that you can see it
with the equivalent eye. If a deficit is present, roughly map out the positions of
the blind spots by passing the finger tip across the visual field.
III. Oculomotor
, (
, (
. These three nerves control eye
movements. All three nerves can be tested by having the patient’s eyes follow
the examiners finger in all four directions (quadrants) and then in towards the
tip of the nose (giving a “crossed-eyed” look). The oculomotor nerve can be
APPENDIX 5A — Neurological Examination 5A-7
further tested by shining a light into one eye at a time. In a normal response,
the pupils of both eyes will constrict.
V. Trigeminal
. The Trigeminal Nerve governs sensation of the forehead and face
and the clenching of the jaw. It also supplies the muscle of the ear (tensor
tympani) necessary for normal hearing. Sensation is tested by lightly stroking
the forehead, face, and jaw on each side with a finger or wisp of cotton wool.
VII. Facial
. The Facial Nerve controls the face muscles. It stimulates the scalp,
forehead, eyelids, muscles of facial expression, cheeks, and jaw. It is tested by
having the patient smile, show his teeth, whistle, wrinkle his forehead, and
close his eyes tightly. The two sides should perform symmetrically. Symmetry
of the nasolabial folds (lines from nose to outside corners of the mouth) should
be observed.
VIII. Acoustic
. The Acoustic Nerve controls hearing and balance. Test this nerve by
whispering to the patient, rubbing your fingers together next to the patient’s
ears, or putting a tuning fork near the patient’s ears. Compare this against the
other ear.
IX. Glossopharyngeal
. The Glossopharyngeal Nerves transmit sensation from the
upper mouth and throat area. It supplies the sensory component of the gag
reflex and constriction of the pharyngeal wall when saying “aah.” Test this
nerve by touching the back of the patient’s throat with a tongue depressor.
This should cause a gagging response. This nerve is normally not tested.
X. Vagus
. The Vagus Nerve has many functions, including control of the roof of
the mouth and vocal cords. The examiner can test this nerve by having the
patient say “aah” while watching for the palate to rise. Note the tone of the
voice; hoarseness may also indicate vagus nerve involvement.
XI. Spinal Accessory
. The Spinal Accessory Nerve controls the turning of the
head from side to side and shoulder shrug against resistance. Test this nerve by
having the patient turn his head from side to side. Resistance is provided by
placing one hand against the side of the patient’s head. The examiner should
note that an injury to the nerve on one side will cause an inability to turn the
head to the opposite side or weakness/absence of the shoulder shrug on the
affected side.
XII. Hypoglossal
. The Hypoglossal Nerve governs the muscle activity of the
tongue. An injury to one of the hypoglossal nerves causes the tongue to twist
to that side when stuck out of the mouth.
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.
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Extremity Strength.
It is common for a diver with decompression illness to expe-
rience muscle weakness. Extremity strength testing is divided into two parts:
upper body and lower body. All muscle groups should be tested and compared
with the corresponding group on the other side, as well as with the examiner. Table
5A-1 describes the extremity strength tests in more detail. Muscle strength is
graded (0-5) as follows:
(0) Paralysis
. No motion possible.
(1) Profound Weakness
. Flicker or trace of muscle contraction.
(2) Severe Weakness
. Able to contract muscle but cannot move joint against
(3) Moderate Weakness
. Able to overcome the force of gravity but not the
resistance of the examiner.
(4) Mild Weakness
. Able to resist slight force of examiner.
(5) Normal
. Equal strength bilaterally (both sides) and able to resist examiner.
Upper Extremities.
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:
Forearm muscles.
Hand muscles.
Lower Extremities.
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 accom-
plished at each joint as in the upper arm.
Muscle Size.
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.
Muscle Tone.
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.
Involuntary Movements.
Inspection may reveal slow, irregular, and jerky move-
ments, rapid contractions, tics, or tremors.
Sensory Function.
Common presentations of decompression sickness in a diver
that may indicate spinal cord dysfunction are:
APPENDIX 5A — Neurological Examination 5A-9
Table 5A-1. Extremity Strength Tests.
Test Procedure
Deltoid Muscles The patient raises his arm to the side at the shoulder joint. The examiner places a
hand on the patient's wrist and exerts a downward force that the patient resists.
Latissimus Group The patient raises his arm to the side. The examiner places a hand on the underside
of the patient's wrist and resists the patient's attempt to lower his arm.
Biceps The patient bends his arm at the elbow, toward his chest. The examiner then
the patient's wrist and exerts a force to strai
hten the patient's arm.
Triceps The patient bends his arm at the elbow, toward his chest. The examiner then places
his hand on the patient's forearm and the patient tries to strai
hten his arm.
Forearm Muscles The patient makes a fist. The examiner
rips the patient's fist and resists while the
patient tries to bend his wrist upward and downward.
Hand Muscles The patient stron
rips the examiner's extended fin
The patient extends his hand with the fin
ers widespread. The examiner
two of the extended fin
ers with two of his own fin
ers and tries to squeeze the
patient's two fin
ers to
ether, notin
the patient's stren
th of resistance.
Lower Extremity Stren
th The patient walks on his heels for a short distance. The patient then turns around
and walks back on his toes.
The patient walks while squattin
(duck walk).
These tests adequately assesses lower extremity stren
th as well as balance and
coordination. If a more detailed examination of lower extremity stren
th is desired,
should be accomplished at each joint as in the upper arm.
In the following tests, the patient sits on a solid surface such as a desk, with feet off the floor.
Hip Flexion The examiner places his hand on the patient's thi
h to resist as the patient tries to
raise his thi
Hip Extension The examiner places his hand on the underside of the patient's thi
h to resist as the
patient tries to lower his thi
Hip Abduction The patients sits as above, with knees to
ether. The examiner places a hand on the
outside of each of the patient's knees to provide resistance. The patient tries to open
his knees.
Hip Adduction The patient sits as above, with knees apart. The examiner places a hand on the inside
of each of the patient's knees to provide resistance. The patient tries to brin
knees to
Knee Extension The examiner places a hand on the patient's shin to resist as the patient tries to
hten his le
Knee Flexion The examiner places a hand on the back of the patient's lower le
to resist as the
patient tries to pull his lower le
to the rear by flexin
his knee.
Ankle Dorsiflexion (ability to
flex the foot toward the rear)
The examiner places a hand on top of the patient's foot to resist as the patient tries to
raise his foot by flexin
it at the ankle.
Ankle Plantarflexion (ability to
flex the foot downward)
The examiner places a hand on the bottom of the patient's foot to resist as the patient
tries to lower his foot by flexin
it at the ankle.
Toes The patient stands on tiptoes for 15 seconds
The patient flexes his toes with resistance provided by the examiner.
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Tingling (“pins-and-needles” feeling; also called paresthesia)
Sensory Examination.
An examination of the patient’s sensory faculties should
be performed. Figure 5A-2a shows the dermatomal (sensory) areas of skin sensa-
tions 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.
Sensations easily recognized by most normal people are sharp/dull
discrimination (to perceive as separate) and light touch. It is possible to test pres-
sure, 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.
Testing the Trunk.
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
Testing Limbs.
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
Testing the Hands.
The hand is tested by running the sharp object across the back
and palm of the hand and then across the fingertips.
Marking Abnormalities.
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.
Deep Tendon Reflexes.
The purpose of the deep tendon reflexes is to determine if
the patient’s response is normal, nonexistent, hypoactive (deficient), or hyperac-
tive (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
APPENDIX 5A — Neurological Examination 5A-11
Figure 5A-2a.
Dermatomal Areas Correlated to Spinal Cord Segment (sheet 1 of 2).
5A-12 U.S. Navy Diving Manual—Volume 5
Figure 5A-2b.
Dermatomal Areas Correlated to Spinal Cord Segment (sheet 2 of 2).
APPENDIX 5A — Neurological Examination 5A-13
prior medical condition or injury that would cause the difference. Isolated differ-
ences 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.
Table 5A-2. Reflexes.
Test Procedure
Biceps The examiner holds the patient's elbow with the patient's hand restin
on the examiner's forearm. The
patient's elbow should be sli
htly bent and his arm relaxed. The examiner places his thumb on the
patient's biceps tendon, located in the bend of the patient's elbow. The examiner taps his thumb with the
percussion hammer, feelin
for the patient's muscle to contract.
Triceps The examiner supports the patient's arm at the biceps. The patient's arm han
s with the elbow bent.
The examiner taps the back of the patient's arm just above the elbow with the percussion hammer,
for the muscle to contract.
Knee The patient sits on a table or bench with his feet off the deck. The examiner taps the patient's knee just
below the kneecap, on the tendon. The examiner looks for the contraction of the quadriceps (thi
muscle) and movement of the lower le
Ankle The patient sits as above. The examiner places sli
ht pressure on the patient's toes to stretch the
Achilles' tendon, feelin
for the toes to contract as the Achilles' tendon shortens (contracts).
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