Pain Physiology and Mechanisms

Question 1

Nociceptive pain

Answer 1

due to activation of nociceptors
- inflammation
- mechanical irritant
- injury

Question 2

Nociplastic pain

Answer 2

due to disturbance in central pain processing
- increase in excitability
- decrease in inhibition

Question 3

neuropathic pain

Answer 3

due to a lesion or disease of the somatosensory system such as a neuropathy

Question 4

What other systems can affect pain

Answer 4

motor and psychosocial

Question 5

Medical terms
1. a-/an-
2. -algia/-algesia/-dynia
3. par-/para-
4. -esthesia
5. kinesio-
6. allo-
7. dys-

Answer 5

1. without
2. pain
3. beside/other/different
4. feeling
5. movement
6. other/abnormal
7. bad/abnormal

Question 6

Nociceptors
- stimuli
- how it travels

Answer 6

• transmit stimuli that may be harmful/noxious (danger or damage)
• information travels from periphery to the spinal cord where the spinal cord to the brain is conscious pain

Question 7

Nociceptive pain causes what type of movement

Answer 7

• mainly causes reflexive movement
• there are many ways that the information gets to the brain

Question 8

What are the nociceptive mechanism of pain

Answer 8

• acute pain: usually less than 12 weeks (it will resolve)
• associated with a known injury
• nociceptors stimulated: pain is perceived
• should be associated with phases of healing
• often times increase in pain with inflammation and decrease in pain as inflammation decreases

Question 9

What mediates inflammation

Answer 9

• cascade of chmeicals
• some examples:
  1. prostaglandins, leukotrienes and thromboxanes
  2. bradykinin
  3. histamines
  4. cytokines (interleukins, TNF)
  5. substance P (neuropeptide associated with pain)

Question 10

What are some treatments of Acute pain
- physical therapy
- medications

Answer 10

PT:
- modalities: cold, heat, TENS
- exercise: stretching/strength
- task oriented functional rehab
- massage
- education

Medications:
- NSAIDs
- Steroidal anti-inflammatory meds
- opioids
- topical analgesics

Question 11

Gate Control theory of pain

Answer 11

• activation of fibers that are faster than C fibers (that carry pain information) can gate ascending painful stimuli at the spinal cord level
• natural use-scratching/rubbing and pressing
• TENS uses this idea as well as massage

Question 12

Nociplastic Mechanism of pain

Answer 12

• Changes in the way that the brain perceives pain
• harmful changes in Nervous system’s response to pain
• chronic pain:
  ~may change movement patterns
  ~ may cause fear and avoidance of movement (kinesiophobia)

Question 13

Hyperalgesia

Answer 13

• associated with peripheral release of bradykinin, cytokines, substance P, prostaglandins
• increased nocicpetor input (peripheral sensitization)
• increased input to the brain (central sensitization)

Question 14

Peripheral sensitization

Answer 14

• abnormal increased sensation above and below where it may normally be affected

Question 15

Central Sensitization

Answer 15

• brain responds to non-noxious stimuli as if they will produce pain
• over time the brain becomes more sensitive to even small amounts of potentially noxious stimuli
• increases release of pain reactions throughout the body
• end result: pain perception doesnt match peripheral stimulus

Question 16

Treatment for chronic pain
- Physical therapy
- medications

Answer 16

PT
- modalities: TENS
- exercises: stretching/strength
- task oriented functional rehab
- massage
- patient education: pain neuroscience and reduced pain catastrophizing

medication:
- antidepressants: Serotonin noradrenaline reuptake inhibitors (SNRIs)
- tricyclic antidepressants

Question 17

Exercise induced hypoalgesia

Answer 17

• endogenous opioids/endogenous cannabinoids
• can be released during exercise, massage and meditation
• interneurons in spinal cord
• periaqueductal gray release of serotonin
• overall increase in release of things such as endorphins that reduce pain

Question 18

Treating pain using pain neuroscience education

Answer 18

• graded motor imagery: some are afraid to move so you can show them movement
• graded activity: take small movements that starts moving the area but puts less pressure on it
• graded exercises: more specific movements

Question 19

Neuropathic mechanism of pain

Answer 19

• damage to peripheral nerves impairs sensation
• impairs sensory information
• happens with a neuropathy

Question 20

Chronic pain and
1. paresthesia
2. allodynia

Answer 20

1. burning, itchy, numbness, tingling, itchy
2. pain from non-painful stimulus
   - generally chronic pain is sharp pain

Question 21

treatment of neuropathic pain
1. physical therapy
2. medications`

Answer 21

1. PT
   - exercises: stretching/strength ETC
   - patient education
   - task-oriented rehab
2. medications:
   - gabapentinoid: decreased nerve pain

Question 22

Psychosocial factors that can affect pain perception

Answer 22

• social support
• social status
• depression/anxiety
• relationships
• past experiences
• stress
• sleep disturbances
• pain self-efficacy: realize pain but also need to realize they can move
• substance use

Question 23

Motor factors with pain physiology

Answer 23

• muscle activity: too much/too little and fear of movement/reinjury
• posture
• movement patterns
• interaction with other body systems

Question 24

treatment of psychosocial factors
1. Physical therapy
2. medications

Answer 24

1. PT
   - exercise: stretching/strength, aerobic ETC
   - task-oriented functional rehab
   - massage
   - pt education
2. medications
   - antidepressants: SNRIs, tricyclic antidepressants

Question 25

Treatment of motor factors
1. Physical therapy
2. medications

Answer 25

1. PT
   - exercises: stretching/strenght, aerobic, posture etc
   - task oriented functional rehab
   - manipulation
   - pt education
2. medications:
   - muscle relaxants

Question 26

Pain assessment- how can it be assessed

Answer 26

• numeric pain rating scale
• visual analog scale
• McGill Pain questionnaire: groups of 20 that describe pain