Sensory
Evaluators (Semmes-Weinstein Monofilaments) provide a non-invasive
evaluation of cutaneous sensation levels throughout the body with
results that are objective and repeatable.
Sensory Evaluators is indicated in diagnoses including nerve compression syndromes, peripheral neuropathy, thermal injuries and
postoperative
nerve repair. Each Touch-Test Sensory Evaluator is individually
calibrated to deliver its targeted force within a 5% standard deviation.
1.
Rest the patient’s extremity on a stable, padded surface. Testing
should be done in a quiet area to help the patient fully attend to the
testing procedure. Occlude the patient’s vision by using a shield or by
having the patient look away.
2.
Explain the testing procedure to the patient and instruct the patient
to respond when the stimulus is felt by saying “touch” or “yes”.
Nonverbal patients may tap the table lightly when the stimulus is felt.
3.
Note any areas of callus, abrasion, scarring or other blemishes by
drawing on the recording form (Hand Screening Form or Foot
Screening Form). While testing, proceed from distal to proximal
and from small to large monofilaments.
4.
It is not necessary to test every area of the skin when performing an
evaluation. Checks may be done over areas innervated by different
nerves. For the hand, test the palmar surface of the index finger and
thumb to evaluate median nerve function; test the little finger and
hypothenar eminence to evaluate the ulnar nerve; and test the dorsum of
the hand to evaluate the radial nerve (see Figure 1). For the foot, test
the sites indicated in Figure 2.
5.
Press the filament at a 90° angle against the skin until it bows. Hold
in place for 1.5 seconds and then remove (see Figure 3). For
monofilaments from 1.65 to 4.08 apply the stimulus in the same location
up to three times to elicit a response. A single response indicates a
positive response. For filaments 4.17 through 6.65, apply the stimulus
one time only.
6.
To test with the Touch-Test 5 Piece Hand Kit, the Touch-Test
Six Piece Foot Kit or the Touch-Test 20 Piece Full Kit, begin with the 2.83 filament. If the patient responds to the
stimulus in all sites, normal cutaneous sensation can be documented
and the examination is completed. If the patient does not respond to
the stimulus, choose the next largest monofilament and repeat the
process.
7.
When the patient indicates a response, record the result using the
colored pencil that corresponds to the color on the handle of the
Touch-Test Sensory Evaluator (Colored Pencils Set). When
representing monofilaments of the same color,
notate which monofilament size was used (see Figure 4). Threshold
levels indicated in Figure 5 can be used to interpret test results.
*If
testing with the 5.07 only, follow instructions #1- #5. Then apply the
5.07 to the test sites shown in Figure 2. Record results using a to
indicate each site with sensation and for lack of sensation.
Note: Touch-Test Sensory Evaluators are precision instruments. Care should be taken at all times
to protect the integrity of the nylon filament. The filament may be
cleaned with a mild instrument disinfectant. Substantially bent or
kinked monofilaments must not be used for testing and should be discarded.
For detailed information, please refer to:
Rehabilitation of the Hand: Surgery and Therapy; Mosby; ed. Hunter, Macken, Callahan; Vol I, 4th Edition; Chapter 9. 1995.