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The Sensory System Examination

Examination Sequence

• 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.