The Sensory System
Examination
Examination Sequence
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Touch
Pain
Deep pain
Temperature
Joint position sense
Vibration sense
Two-point discrimination
Touch
• Ask the patient to close the eyes and to
respond verbally to each touch.
• Touch the skin with a small piece of
cotton wool, tissue paper and light
digital touch are alternative stimuli.
• Avoid regularly timed stimuli so that
the patient dose not anticipate the test.
• Examine the spinal segments
sequentially (e.g. in the upper limb start
on the outer border of the arm (C5),
then proceed downwards to the lateral
border of the forearm and thumb (C6),
index finger (C7), etc.
• Compare sensation on each limb for
symmetry.
• Outline the border of any abnormal
area of sensation by testing from
the hypo aesthetic area toward
normal.
• If the patient complains of dysaesthesia
(an uncomfortable or abnormal feeling)
map the normal to the abnormal area.
Pain
Because of the risk of transmitted
hepatitis and HIV, use a new dress
making pin or a dedicated disposable
pin. Avoid using a hypodermic needle,
which is too sharp.
• Establishing a baseline for sharpness
(e.g. sternal area) before examining the
limb.
• Test pin prick sensation down each
limb and over the trunk.
• Ask the patient to report if the quality of
sensation changes. Either becoming
blunter (hyperesthesia).
• Test each dermatome in turn, but also
bear in mind peripheral nerve
distribution.
• Map out the boundaries of any
abnormal area as described for light
touch
Deep Pain
• Squeeze muscle bellies (e.g. calf,
biceps or apply firm compression over
the patient’s fingernail and toenail
beds.
• Ask the patient to report as soon as the
sensation become painful.
Temperature
• Touch the patient with a cold object
(e.g. a tuning fork ) and ask the patient
about the quality of the temperature
sensation. This can be performed on
face, forearms, hands, trunk and legs.
• For Improved discrimination fill two
plastic containers (e.g. serum bottles)
one with and the other with cool water.
Ask the patient to close the eyes and
to distinguish between warm and cool
while applying the containers to the
skins in a random sequence.
Joint position sense (JPS)
• Test this sensation initially at the most
distal part of the limb. In the upper
limb, first test at the distal
interphalangeal joint of the index finger.
• Show the patient the intended
movement of the joint and name them
(e.g. ‘that’ s up “and ‘that’ s down’)
• Ask the patient to close the eyes and to
avoid guessing.
• Grasp the proximal phalanx of finger
with one hand while holding the medial
and lateral borders of the distal phalanx
of the same finger with the other thumb
and finger .
• Move the patient’s distal phalanx
up and down.
• Ask the patient to identify the
direction of movement during a
random sequence of small
movements (e.g. up, down, down,
up).
• Then test the contralateral limb.
• If there is any abnormality of JPS the
distal interphalangeal joint, test at the
proximal interphalangeal joint and, if
necessary, at the metacarpophalangeal
joint, progressing to the wrist and
elbow if JPS remains impaired.
• In the lower limb start at the
interphalangeal joint of the bog toe,
holding the proximal phalanx in the
other hand
• Take care to ensure that the examiner’s
finger do not rub against the patient’s
other toes.
• If there is impairment proceed to
examine the metacarpophalangeal joint
and, if necessary, the ankle and knee
Vibration Sense
• Examine the patient with his or her
eyes closed.
• First hold the vibrating tuning fork (128
Hz) over the sternum so that the patient
identifies the sensation.
• In the lower limbs test the big toe. If
necessary, next move proximally in
turn to the ankle tibial shaft and
tuberosity and the anterior iliac crest.
• In the upper limbs test the
interphalangeal joint of the forefinger; if
impaired proceed the
metacarpophalangeal joint and the
more proximal bony prominences.
• If in doubt, ask the patient to identify as
soon as the tuning fork stops vibrating
when ‘stopped’ by the examining
fingers.
Two point discrimination
• Use a two-point discriminator if one is
available, or and opened-out paper clip.
• Perform the test with the patient’s eyes
closed.
• Hold the patient’s index finger and apply
either one or two the test object points to the
finger pulp.
• Ask the patient to determine if one or two
stimuli were applied.
• Then determine the minimum distance at
which two points are felt to the separate.
• Ask the patient to determine if one or
two stimuli were applied.
• Then determine the minimum distance
at which two points are felt to the
separate.
• Perform the test on the pulp of both
index fingers and thumbs.
• Repeat the test several times during the
course of the clinical examination to
determine variation in two-point
discriminatory distance.