Lecture 9: Clinical 1: Sensation Flashcards
If patient does not have sensory symptoms, a screening examination for asymptomatic abnormalities includes testing…..
(1) Vibration and joint position in fingers and toes;
(2) Light touch and pin prick sensation in hands and feet.
When you’re approaching sensory examination…
- If you suspect a peripheral neuropathy, determine _______
- If you suspect a spinal cord lesion, look for _________
- If you suspect a peripheral neuropathy, determine if loss of sensation in peripheries (glove and stocking).
- If you suspect a spinal cord lesion, l_ook for a sensory level over the trunk or arms._
What sort of symptoms would you see in Upper Motor Neuron problems?
- Upper motor neuron problem
- Weakness, ↑ tone and ↑ reflexes
- 1/2 body affected or spinal cord level (e.g. below umbilical level)
What sort of symptoms would you see in Lower Motor Neuron problems?
- Lower motor neuron problem
- Weakness, ↓ tone and ↓ reflexes
- Nerve root or peripheral nerve distribution
When you’re examining the patient (light touch, pain, temperature etc.) make sure that….
- Patient’s eyes closed
- Demonstrate stimulus over a part where you know stimulus will be normal
- Apply stimulus at irregular intervals so that the patient can’t anticipate them
- Don’t slant questions towards abnormal, e.g. ‘is that sharp?’
- Map sensory loss by moving from area of decreased sensation to area of normal sensation
- E.g. T1/C5 junction for some clear cut sensory problem, due to spinal nerves at the junction starts to go to the arms*
- Draw a diagram to show the sensory abnormalities
What are some Basic Sensory Functiont tests?
Sensation can be tested in several ways. For example, with patient’s eyes closed,
- 1) Light touch*
- 2) Pain*
- 3) Temperature*
- 4) Joint position (proprioception)*
- 5) Vibration*
Describe the Light touch sensory function test
Instrument: A wisp of cotton wool
- Ask the patient to say “yes” each time a touch is felt. Normally patients detect most light touches on the fingertips or toes.
- If use fingertip (not recommended), don’t drag your finger over skin. This is tickling and is allied to pain sensation rather than light touch.
Describe the Pain sensory function test
Instrument: Saftey pin (pinprick)
- Discard the pin after use. Don’t use an intravenous needle or a split wooden spatula. An intravenous needle may puncture the skin and the split wooden spatula does not provide an adequate stimulus.
- *
- Demonstrate the stimulus. Touch the patient firmly without puncturing the skin. Ensure the patient reports the sharpness of the stimulus and not a feeling of contact or pressure.
- Apply two or three stimuli in a localised area; a single pinprick may not register pain. Don’t apply consecutive stimuli to the same spot.
Sometimes it is helpful to ask the patient to distinguish between sharp or blunt stimuli (different side of the pin).
Describe the Joint position sensory function test
Instrument: Passive joint movement
- Demonstrate which movements are up or down while the patient is looking. Then test with the patient’s eyes closed.
- In hands, test proprioception in middle finger.
- Hold each side of middle phalanx with one hand. Hold either side of distal phalanx with other hand. (Do not hold the distal phalanx between pulp and nail, otherwise pressure may allow the patient to identify direction of movement.)
- Move the distal phalanx up or down in a random order. Ask the patient to report the direction of each movement.
- If proprioception is impaired in fingers, test it in wrist and elbow.
- In legs, test joint position sensation in big toe.
- Hold each side of proximal phalanx with one hand. Hold each side of distal phalanx with other hand.
- Move the distal phalanx up or down in a random order.
- If proprioception is impaired in toes, test it in ankle or knee
Describe the Vibration sensory function test
Instrument: 128 Hz tuning fork
- Demonstrate the stimulus by placing the base of the tuning fork on the patient’s sternum. Make sure that the patient reports vibration, not the sound of the tuning fork or pressure.
- Test vibration sensation over the pulp of the middle finger and the big toe. Positive stimuli (vibration) and negative stimuli (non-‐vibrating tuning fork) are presented in a random order.
- If vibration sensation is absent over digits, test it over proximal bony prominences:
- In the arm, test distal end of radius & olecranon;
- In the leg, test medial malleolus & tibial tuberosity & anterior superior spine of ilium.
What kind of discriminatory sensory function tests are there?
1) Accurate light touch localisation
2) Two point discrimination
3) Sterognosis
4) Graphaesthesia (number wriitng on skin)
5) Bilateral simultaneous stimulation
Describe the following Discrimatory Snesory Function test:
Accurate light touch localisation
- Discriminative sensation may be impaired with lesions in the parietal lobe or the thalamocortical projections, but it isn’t tested routinely.
Describe the following Discriminatory Snesory function test
Two point discrimination
Instrument: Compass (or pair of dividers with blunt points)
This tests the ability to distinguish one from two touches which are close together. Test over the fingertips.
Describe the following Discriminatory Snesory function test:
Stereognosis
Instrument: Easily recognised small objects such as coins, a key, saftey pin etc.
- This only can be tested if touch, pin prick and vibration sensation in the hand are normal and if the patient can move the hand.
- See if the patient can feel and recognise objects placed in the hand with eyes closed. Check the normal hand first.
Describe the following Discriminatory Snesory function test:
Graphaesthesia
See if the patient can recognise single digit numbers traced on the palm of the hand
