Ch. 7: Somatosensation - Clinical Application

Question 1

What are the Somatosensory Contributions to Function?

Answer 1

• Contributes to smooth, coordinated movement.
• Helps protect from injury.
• Contributes to understanding (perception) of our environment

Question 2

How do we test somatosensation?

Answer 2

• Test conscious relay pathways
• Quick Screenings - if not problems indicated
• Complete Evaluations - if problems are indicated in screening or if refered to us for them.

Question 3

What are the conscious relay pathways that we test?

What are their named neurons?

Answer 3

• Discriminative touch
  
  • A-beta (exteroception), DC?ML
• Conscious proprioception
  
  • Ia, Ib, II DC/ML
• Fast pain - tell sharp stimuli from dull
  
  • A-delta, anterolateral column
• Discriminative temperature - discriminate hot from cold
  
  • A-delta, anterolateral column

“Cortical” sensations” - intact operations of the first 4 - where cortex process sensory info to make meaning

Question 4

What do we test in a Quick Screening?

Answer 4

• Vibration (distal joints)
  
  • A-beta, DC/ML
• Conscious proprioception (distal joints)
  
  • Ia, Ib, II DC/ML - position sense (ex: can they detect that big toe is flexed or extended with eyes closed)
• Fast pain
  
  • A-delta, anterolateral column - sharp/dull

Question 5

What do we evaluate in a Complete Evaluation?

Answer 5

• Sensory Threshold
  
  • Myofilaments - lightest touch possible
• Sensitivity
  
  • Two-point discrimination
• “Higher” (“cortical”) sensations
  
  • “Stereognosis” - descirbe familiar objects w/o looking (ex: key)
• Pattern of loss
  
  • Pain, temp, touch → pt education if stimulus not coming back.

Question 6

What are the limits to formal sensory examination

Answer 6

• Unconscious
• Unresponsive

Cannot get good results

Question 7

What is Anesthesia?

Answer 7

Lack of sensation

Question 8

What is Analgesia?

Answer 8

Lack of pain sensation specifically

Question 9

What is Hypesthesia?

Answer 9

Less than normal sensation

Question 10

What is hypalgesia?

Answer 10

Less than normal amount of pain sensation

Question 11

What is Paresthesia?

Answer 11

Abnormal sensation (painless, abnormal, tickling, tingling)

Question 12

What is dysesthesia?

Answer 12

Absensce of direct stimuli

(unpleasant, abnormal, burning, shooting)

Question 13

What is allodynia?

Answer 13

Type of Dysesthesia

• Patient perceives pain from a stimulus that normally does not cause pain
• Ex: how sensitive skin is after sun burn.

Question 14

What is hyperalgesia?

Answer 14

• Normally perceived as pain → produces response out of proportion.
• Result of damage to nervous system.

Question 15

What is Ataxia?

Answer 15

Lack of coordinated movement

Question 16

What is the Order of LOSS of senstaion with compression?

Answer 16

1. Conscious proprioception & discriminative touch
2. Cold
3. Fast pain
4. Heat
5. Slow pain

Question 17

What is the Order of RETURN of senstaion after compression?

Answer 17

The reverse of loss:

1. Slow pain
2. Heat
3. Fast pain
4. Cold
5. Conscious proprioception and discriminative touch

Question 18

What is the definition of pain?

Answer 18

“Pain is an unpleasant sensory and emotional experience”

Question 19

What locations of the brain may respond to pain?

Answer 19

• Affective
• Emotional
• Behavioral

Limbic terminaltes in the autonomic areas

Question 20

What is Peripheral Sensitization?

Answer 20

Sensitize peripheral neuron = low threshold for activation, low amt of stimulus that produces an AP

Question 21

What are the possible functions of FAST pain?

What named neurons are used?

Answer 21

Withdraw/escape from pain.

(acute, A-delta, superficial)

Question 22

What are the possible functions of SLOW pain?

What named neurons are used?

Answer 22

Rest damaged tissue

(chronic, C, deep)

Question 23

FAST pain uses what pathway?

Answer 23

Spinothalamic pathway

Question 24

SLOW pain uses what pathway?

Answer 24

Divergent Pathways

Question 25

What is Referred Pain?

Answer 25

Convergence of somatic [body] and visceral [organs] axons in spinal cord (ex: left arm & heart converge at same spot - heart never hurts, brain learns it is always arm pain. Heart attack = brain thinks arm pain)

Question 26

What is the Pain Matrix?

Answer 26

Brain structures that regulate pain. Can create pain in absence of stimulus.

Question 27

The LATERAL pain system uses what pathway?

Answer 27

Spinothalamic | (Conscious Relay Pathway)

Question 28

The MEDIAL pain system uses what pathway?

Answer 28

Spinolimbic | (Diverengent Pathways)

Question 29

The pain experience envolves what 3 aspects? What pathways do each of them use?

Answer 29

1. Sensory → Discriminative aspects * Spinothalamic 2. Motivational →Affective aspects * Spinolimbic and Spinoreticular 3. Cognitive →Evaluative aspects * Prefrontal lobes

Question 30

What are the 2 "Top-Down" responses to pain? What do they do?

Answer 30

1. Antinociception * pain relief 2. Pronociception * increase or amplify - ability to "experience" pain

Question 31

What is the first place pain is recepted?

Answer 31

Dorsal Horn

Question 32

What is the Dorsal Horn's NORMAL response to pain?

Answer 32

Action release, AP, normal reporting of pain

Question 33

What is Suppressed Nociception in the Dorsal Horn?

Answer 33

Diminished pain | (ex: "rub it where it hurts")

Question 34

What is "Sensitized" processing in the Dorsal Horn?

Answer 34

Temporary, short term increase in strength of pathway Excessive pain!

Question 35

What is "Reorganized" processing in the Dorsal Horn?

Answer 35

Long Term Potentiation (LTP) → excessive pain! Reconstruction in synapses to make it easier to send signal

Question 36

What susbstance helps you preceive MORE pain?

Answer 36

Substance P

Question 37

How do you stop pain in the Periphery?

Answer 37

Remove stimulus/irritants | (ex: massage to remove edema)

Question 38

How do you stop pain in the Dorsal Horn of the Spinal Cord?

Answer 38

Counterirritant Theory - presynaptic inhibition of pain neurons ("rub it where it hurts") Ex: TENS unit, massage, etc.

Question 39

How do you stop pain in the Brainstem Descending Systems?

Answer 39

* Your own thoughts can turn down pain. * Periaqueductal gray = termination of spinomesencephalic → **starter** for all brainstem to spinal cord pathways

Question 40

How do you stop pain at the subcortical level?

Answer 40

* Potential to slow pain messages body wide * Hypothalamus, pituitary gland, adrenal medulla (opiate-mediated...**endorphins!**) → lasts longer than pain meds (up to several hours)

Question 41

How do you stop pain at the cortical level?

Answer 41

Pathway from cortex to hormonal level -\> can turn on body wide reduction system by thought. Can turn on brain stem decending pathway. (Ex: placebos, distraction, perception)

Question 42

How could you summarize WHY the pain matrix is important to us as PT's?

Answer 42

* We can influence pain at multiple levels to decrease pain * Modalities in the periphery * Exercise for body wide * Mental for body wide

Question 43

What are examples of Pronociception at Level I, II & IV

Answer 43

* Pain amplification * Level I: peripheral sensitization * pathological = pain w/o stimulus * Level II: LTP of pain pathway and other malfunctions * increase effectiveness of pathway = more pain * Level V: psychological stress can amplify pain * dispear, hopelessness

Question 44

What is the difference between Acute and Chronic Pain?

Answer 44

Question 45

What is Chronic Pain?

Answer 45

healing extend beyond normal tissue healing time

Question 46

# Define the 2 types of Chronic Pain?

Answer 46

1. Nociceptive * Continuing pain stimulus * Neurons functioning normally 2. Neuropathic * NO continuing pain stimulus * Neurons NOT functioning normally * \*\*\*Hradest pain to deal wiht → cannot find cause