Sensory examination

Before initiating the examination of sensory function, the testing environment should be identified and prepared, needed equipment gathered, and consideration given to patient preparation (i.e., what information and instruction will be provided).

1. Sensory Examination Anand vaghasiya

2. SCREENING of SENSORY EXA. Screenings consist of a series of brief tests that provide the therapist an “overview” of the system of interest (e.g ., musculoskeletal, neuromuscular ). To perform a sensory screening, several easily tested(i.e ., requiring little or no specialized equipment) modalities of sensation are selected. It is important to select modalities from each of the general categories of sensations .

3. For example, the therapist might select pain and light touch (superficial), kinesthesia and vibration (deep), and two-point discrimination or stereognosis (combined ). screening tests for mental status (arousal, attention, orientation, cognition, and memory), vision, and hearing acuity should be performed prior to the sensory examination.

4. PREPARATION FOR ADMINISTERING THE SENSORY EXAMINATION Before initiating the examination of sensory function, the testing environment should be identified and prepared , needed equipment gathered , and consideration given to patient preparation (i.e., what information and instruction will be provided).

5. 1. Testing Environment The sensory examination should be administered in a quiet , well-lighted area . Depending on the number of body areas to be tested, either a sitting or recumbent position may be used . If full body testing is indicated, both prone and supine positions will be required and use of a treatment table is recommended to allow examination of each side of the body.

6. 2. Equipment Pain . A large-headed safety pin or a large paper clip that has one segment bent open.

7. 3.Temperature Two standard laboratory test tubes with stoppers.

8. 4.Light touch . A camel-hair brush, a piece of cotton, or a tissue.

9. 5.Vibration . Tuning fork and earphones (if available, to reduce auditory clues). Tuning forks are made of steel or magnesium alloy and grossly resemble a two-pronged fork (tines) (e.g., 128, 256, or 512 Hz).

10. Stereognosis (object recognition ). A variety of small, commonly used articles such as a comb, fork, paper clip, key, marble, coin, pencil.

11. 6.Two-point discrimination . Several instruments are available to measure two-point discrimination. A two-point discrimination aesthesiometer . is a small handheld instrument designed to measure the shortest distance that two points of contact on the skin can be distinguished. It consists of a small ruler with one stationary and one moveable ( sliding) tip coated with vinyl. he vinyl coverings help to minimize the impact of temperature on perception of contact . For finer gradations in measurement (e.g., fingertips ),small circular disks can be used to measure two-point discrimination (Fig. 3.10). here instruments typically allow quantification of two-point discrimination from 1 to 25 mm.

12. Patient preparation A full explanation of the purpose of the testing should be provided. he patient also should be informed that cooperation is necessary to obtain accurate test results. It is of considerable importance that the patient be requested not t o guess if uncertain of the correct response . During the examination, the patient should be in a comfortable, relaxed position. Preferably, the tests should be performed when the patient is well rested. Considering the high level of concentration required, it is not surprising that fatigue has been noted to affect results of some sensory tests adversely.

13. THE SENSORY EXAMINATION T he superficial ( exteroceptive ) sensations are usually ex- E amined first, in as much as they consist of more primitive responses, followed by the deep (proprioceptive), and then the combined cortical sensations. If a test indicates impairment of the superficial responses, some impairment of the more discriminative (deep and combined) sensations also will be noted and is a contraindication to further testing (e.g., lack of touch sensation would be a contraindication for testing stereognosis ). T hat is, the primary modality of sensation (touch) must be sufficiently intact to permit meaningful testing of cor - tical sensory function (ability to identify objects placed in the hand ).

14. For each sensory test, the following data will be generated: the modality tested he quantity of involvement or body surface areas affected (pattern identification) the degree or severity of involvement (e.g., absent, impaired, or delayed responses) Localization of the exact boundaries of the sensory impairment he patient’s subjective feelings about changes in sensation he potential impact of sensory loss on function (i.e., activity limitation, disability)

15. During testing, the application of stimuli should be applied in a random, unpredictable manner with variation in timing . This will improve accuracy of the test results by avoiding a consistent pattern of application, which might provide the patient with “clues” to the correct response . During application of stimuli, consideration must be given also to skin condition. Scar tissue or callused areas are generally less sensitive and will demonstrate a diminished response to sensory stimuli.

16. Table presents terminology used to describe common sensory impairments.

17. Superficial Sensations Pain Perception Temperature Awareness Touch Awareness Pressure Perception

18. Pain Perception his test is also referred to as sharp/dull discrimination and indicates function of protective sensation . To test pain awareness, the sharp and dull ends of a large headed safety pin, a reshaped paper clip (the segment pulled away from the body of the paper clip provides a sharp end), or a single-use protected neurological pin (Medipin) are used . he instrument should be carefully cleaned before administering the test and disposed of immediately afterward The sharp and dull ends of the instrument are randomly applied perpendicularly to the skin . To avoid summation of impulses, the stimuli should not be applied too close to each other or in too rapid a succession .

19. To maintain a uniform pressure with each successive application of stimuli, the pin or reshaped paper clip should be held firmly and the fingers allowed to “slide” down the pin or paper clip once in contact with the skin. This will avoid the chance of gradually increasing pressure during application. he instrument used to test pain perception should be sharp enough to deflect the skin, but not puncture it . Response he patient is asked to verbally indicate sharp or dull when a stimulus is felt. All areas of the body may be tested.

20. Temperature Awareness This test determines the ability to distinguish between warm and cool stimuli. Two test tubes with stoppers are required for this examination; one should be filled with warm water and the other with crushed ice. Ideal temperatures for cold are between 41°F (5°C) and 50°F (10°C) and for warmth, between 104°F ( 40°C) and 113°F (45°C). Caution should be exercised to remain within these ranges, because exceeding these temperatures may elicit a pain response and consequently inaccurate test results. The side of the test tube should be placed in contact with the skin (as opposed to only the distal end).

21. This technique provides sufficient surface area contact to determine the temperature. The test tubes are randomly placed in contact with the skin area to be tested. All skin surfaces should be tested. Response The patient is asked to reply hot or cold after each stimulus application .

22. Touch Awareness his test determines perception of tactile touch input. A camel-hair brush, piece of cotton (ball or swab), or tissue is used. T he area to be tested is lightly touched or stroked . Examination of finer gradations of light touch can be quantified using monofilaments. Response he patient is asked to indicate when he or she recognizes that a stimulus has been applied by responding “yes ” or “now.”

23. Note: A quantitative score for pain perception, temperature, and light touch awareness can be obtained by dividing the number of correct responses by the number of stimuli applied (normal response would be 100% ).

24. Pressure Perception The therapist’s fingertip or a double-tipped cotton swab is used to apply a firm pressure on the skin surface . This pressure should be firm enough to indent the skin and to stimulate the deep receptors . This test can also be administered using the thumb and fingers to squeezee the Achilles tendon. Response he patient is asked to indicate when an applied stimulus is recognized by responding “yes” or “now.”