Sensory exam of the limbs

Question 1

How do you assess light and sharp touch?

Answer 1

1. ask the patient to close their eyes and instruct them to say yes when they can feel you touch them
2. for upper and lower limbs, compare each dermatome one at a time and ask the patient whether the sensations feel the same on each side
   - for light touch use cotton wool
   - for sharp touch use a shape but blunted object
3. you must touch the patient’s sternum FIRST so that they have a reference of how it should feel

Question 2

What ascending tract is activated for light touch?

Answer 2

dorsal column

Question 3

What ascending tract is activated for sharp touch?

Answer 3

spinothalamic

Question 4

How do you assess proprioception?

Answer 4

1. with the patient’s eyes closed, gently + passively flex/extend a digit at the distal phalanx
2. ask them to say whether you are moving it up or down
3. if they are unable to do so, move to a more proximal joint until they are correct

Question 5

What ascending tract is activated when assessing proprioception?

Answer 5

Dorsal column

Question 6

How do you assess vibration?

Answer 6

1. using a 128Hz tuning fork, hit it against a firm surface to start it vibrating
2. place it against the patient’s sternum as a reference
3. with their eyes closed, touch the vibrating tuning fork against a distal bony prominence and ask them to say ‘stopped’ when they feel you stop the vibration
4. if they are unable to do so, move to a more proximal bony prominence until they are correct

Question 7

What ascending tract is being activated when you assess vibration?

Answer 7

Dorsal column