CLINICAL EXAMINATION OF SENSORY SYSTEM

A clinical examination of the sensory system evaluates a patient's ability to sense pain, temperature, light touch, vibration, and joint position. It's part of a neurological exam that assesses the nervous system

1. Clinical examination of sensory system

2. AIM: To test various forms of sensations Principle: Dermatomal rule The region of the skin innervated by a single dorsal root ganglion

3. A   dermatome  is an area of the skin that is supplied by a single spinal nerve that sends information to the brain for processing

4. Apparatus: Cotton A lgometer T unning fork Pin Compass aesthesiometer Familiar objects Cold and worm water

5. Tactile sensibility—light Touch Pressure Tactile localization and Tactile discrimination Pain Temperature Position sense Vibration sense Stereognosis Any abnormal sensation Sensations:

6. Explain to the subject what you are going to do. Stand on the right side of the subject/patient. If you are examing a female patient then their attendant is compulsory or nurse should be there.

7. Ask the subject to close his eyes and examine. Always compare the corresponding points on both sides of the body.

8. Touch with low threshold. By wisp of cotton wool test from different parts of body. Tell the subject to say yes every time he feels the touch. Light touch

9. Touch sensibility— Complete absence– Anaesthesia Partial loss– Hypoaesthesia Exaggerated– Hyperaesthesia

10. Sustained touch sensation– with blunt object Note any disturbance in its perception over different portion on the body Pressure

11. Localization of the touch i.e. tell precisely the position of the both the parts touched. Tactile localization

12. The ability to distinguish between two adjacent touch stimuli to the skin. It is greater on—Thumb 2-3mm - sensory Fingers units are small Lips and overlap Tactile discrimination

13. It is small on– Back 65mm – where the sensory units are large and widely separated. It depends upon intactness of touch sensibility and parietal lobe.

14. Tactile discrimination is tested by– compass aesthesiometer . The 2 limbs of instrument are separated and subjects skin is touched by both ends.. Ask whether he is being touched with one or both the points.

15. Superficial pain :- cutaneous stimulus by pin Use the point of ordinary domestic pin – ask the subject to distinguish between the sharpness of point ( relative size ) and pain. Pain

16. Deep/Pressure pain :- Tested by squeezing the muscles or tendon- achilles . Disturbed in tabes dorsalis

17. Pain sensibility:-- Absent– Analgesia Partial loss– Hypoalgesia Increased--- H yperalgesia

18. Tested by using test tubes containing warm and cold water. Temperature

19. Hold one of subjects joints– move up and down. Ask subject to tell which way it has been moved. He should be able to recognize the movement of only few degrees (<10) at all joints. Position sense

20. Sensory ataxia: Defective sense of position. *Note: while testing sense of position do not allow the part tested to touch any other skin surface— If done subject is able to appreciate its position by his sense of touch.

21. A tuning fork of 128Hz is made to vibrate Foot of tuning fork is place on subcutaneous bone in the region to be tested– shin and malleolus. Ask the subject whether he perceives the vibration. Compare on other side Vibration sense

22. Vibration sensibility is lost in Tabes dorsalis Peripheral neuropathies– DM & vit deficiency Posterior column disorders Vibration sense

23. Ability to recognize familiar objects- such as coins, pencil, pen, scissors etc.. by handling them without looking at them. Cerebral cortex plays a major role. Astereognosis :loss of stereognosis– damage to parietal lobe Stereognosis

24. Paraesthesia : presence of abnormal sensation over body without external stimuli. Examples: feeling of pins & needles numbness, pressure tightness, itching Formication  insect crawling over body Any abnormal sensation

25. Sensation Right side Left side Light touch Pressure sense Tactile localization Tactile discrimination Observation

26. Right side Left side Superficial pain Deep(pressure) pain Thermal sense Sense of position Vibration sense stereognosis Abnormal sense