American   Academy   f   Manual   Medicine

Home  Search  Pain referral  Trigger points  Cranial nerve  Spinal nerve  Historical  About us  Contact us  Site map 

 

Sensory Function

Sensation

Sensory evaluation assesses peripheral nerves and tracts for pain, touch, vibration, temperature and position sense. The individual’s vision must be diverted to avoid cuing or compensation in addition to being well rested to avoid sensory depravation (hypoesthesia). The practitioner should use uniformity of object to elicit stimuli and determine symmetrically if perception is equal. Consistency or sensory perception is determined through repetition and frequently can be perplexing due to the same pressure or joint position being applied or initiated, but resulting in differing subjective report from the individual. The practitioner should note positive or negative findings as it pertains to the anatomical area and which side of the body was stimulated.

 

1. Light Touch – Inform the individual that you will be touching them at various points of their body with either your fingertip or an object while their eyes are closed. They will need to tell you which of the two you are using. As sensation varies from point to point you will need to duplicate contact to the opposing side at approximately the same location.

 

2. Superficial Pain - Use a sharp point, such as a broken swab stick or tongue blade, and alternate with a small dull object, such as the end of an unbroken swab stick or tongue blade. The dull object must be of the same material as the sharp point. Ask the individual to close their eyes and tell you, where they feel the pain and if it is sharp or dull.

While this technique may be applied to any site on the body, usually the soles of the feet or the palms of the hands are used. You can press or draw points of an object across the skin. Persons with neuropathy will find it difficult to distinguish between sharp and dull. Perform bilaterally to determine between a mono-neuropathy and that of a poly-neuropathy. To the manual medicine practitioner it is of special importance to note if it is a glove or stocking distribution, or if the entire extremity is involved. Additionally you would want to note if the loss of sensation was sudden in onset or insidious as well as how rapidly progressive it is.

 

3. Joint Position Sense – This check is performed testing the peripheral joints only. Should they test well, those proximal are assumed to be normal. Should the individual test poorly distally, the more proximal joints would be tested to establish the degree of impairment. The individual can either be seated on the side of the table or in supine recumbency. While grasping the medial and lateral aspects of the toes or digits, the practitioner requests for the individual to tell them whether they have moved the digit up or down.

 

4. Vibration – As in the joint positions check, if vibration is felt distally, it is assumed that proximal vibratory sensation would be experienced as well. This is performed using a vibrating low-frequency tuning fork (128Hz). The practitioner taps the tuning fork and places the base against the medial malleolus or the proximal phalanx of the great toe. Then the individual is requested to inform the practitioner if they feel the vibration, and if so, when does it stop. Immediately following their statement, that they can no longer feel it, the practitioner moves the tuning fork to a similar sized joint on their own body to determine whether vibration can still be experienced. If vibration should continue to be experienced after relocation to the practitioner, sensory perception may be compromised in the individual. Then the practitioner may choose to retest the same site or move more proximally to determine degree of impairment. This check should be performed bilaterally.

Other sites that may be tested are: patella, vertebral spinous processes, iliac crests or ulna prominences. Should you suspect the individual is delaying their answer to test well, you may dampen the tuning fork to cause cessation of vibration. While this usually is not necessary, occasionally you will have an individual, that out of vanity, modesty, or a deliberate attempt to mislead, such as in having alcoholic neuropathy, will attempt to masquerade their condition.

 

5. Temperature, as with all forms of sensory testing, it is constructive to map on a body form chart the areas of sensory loss as well as proximally where there is a restoration of normal sensation. To test for temperature sensation most authors recommend the utilization of warm and cold test tubes of water. These test tubes should be alternated symmetrically with the individual requested to discriminate between the two. The practitioner should be aware of tubes that are either hot or frozen can be initially perceived as the same sensation and will result in the sudden withdrawing or avoidance of contact by the individual. Therefore, moderate heat and cold is more reliable for testing.

 

6. Two-point Discrimination - with the individuals’ eyes closed, the practitioner utilizes two of the same type of sharp objects (e.g. broken tongue blade) and places them at the same fixed point. After they are assured the individual’s vision is obstructed from the area to be tested they gradually separate the contact points of the two objects and request the individual to remark when they can feel the object separated. Care should be used to apply equal pressure on the objects. Dependent upon the area of the body being tested, the individual’s ability to distinguish separation will be experienced. Included are some recommended values for two point discrimination from Correlative Neuroanatomy by Stephen G. Waxman, MD, PhD and Jack deGroot, MD, PhD. Normal: soles of feet, 1.5-2 cm; shin, 4 cm; dorsum of hands, 3 cm; palms of hands, 1.5-2 cm; fingertips, 0.3-0.6 cm.

 

 

Back to Top

 

 

Return to Search 

 



Home  Search  Pain referral  Trigger points  Cranial nerve  Spinal nerve  Historical  About us  Contact us  Site map 

Continuing Education © Copyright 2001, 2004, 2006. All rights reserved.