SM_250a: Acute vs. Chronic Pain

Question 1

Chronic pain is pain lasting ____

Answer 1

Chronic pain is pain lasting > 3 months

Question 2

Nociceptive pain is ____, while neuropathic pain is ____

Answer 2

Nociceptive pain is due to tissue injury, while neuropathic pain is due to damage to the nervous system

Question 3

Describe the ascending pain pathway

Answer 3

Ascending pain pathway

• Injury -> cell damage -> cytokines (mainly prostaglandins) released -> afferent neuron goes into dorsal horn of spinal cord -> release of substance P -> activates motor neuron -> cross over -> spinothalamic tract -> thalamus -> somatosensory cortex and other areas of brain
• A delta and C fibers are primary afferent neurons: peripheral nerves that cross over into spinal cord

Question 4

Thalamus is ___ for pain signals

Answer 4

Thalamus is relay station for pain signals

(spinothalamic tract -> thalamus -> somatosensory cortex and other areas of brain)

Question 5

Dorsal horn ___ peripheral nervous system

Answer 5

Dorsal horn is NOT in the peripheral nervous system

Question 6

Modulation is when ____

Answer 6

Modulation is when inhibitory signals from the brain and spinal cord to the dorsal horn of the spinal cord limit transfer of incoming sensory input to the brain

(ability to do this in acute phases of injury leads to a person’s ability to withstand severe pain for a short period of time and control response to any pain stimuli, patients with chronic pain often have some loss of function of descending inhibitory modulation)

Question 7

Patients with chronic pain often have ____ of descending inhibitory modulation

Answer 7

Patients with chronic pain often have loss of function of descending inhibitory modulation

Question 8

Plasticity is ____

Answer 8

Plasticity is nervous system’s ability to reorganize itself and adjust its function and activity in response to new situations or changes in their environment

Question 9

In chronic pain, plasticity is maladaptive because ____

Answer 9

In chronic pain, plasticity is maladaptive because it contributes to a more hypersensitized nervous system responsible for perpetuation of chronic pain

Question 10

Describe peripheral sensitization

Answer 10

Peripheral sensitization

• Occurs with changes in signaling in the peripheral nervous system
• Reduces threshold for firing of nociceptors in skin
• Can happen acutely or chronically
• May result in allodynia or hyperalgesia

Question 11

Allodynia is ____

Answer 11

Allodynia is pain to a non-painful stimulus

Question 12

Hyperalgesia is ____

Answer 12

Hyperalgesia is severe pain to a mildly painful stimulus

Question 13

Describe the steps in peripheral sensitization

Answer 13

Peripheral sensitization

1. Substances released by damaged tissue augment the response of nociceptive fibers
2. Electrical activation of nociceptors causes the release of peptides and neurotransmitters that further contribute to the inflammatory response
3. Result in hyperalgesia

Question 14

Central sensitization is a persistent state of ____, ____ threshold for what causes pain, and maintains ____

Answer 14

Central sensitization is a persistent state of high reactivity, lowers threshold for what causes pain, and maintains pain even after initial injury might have healed

Question 15

Describe central sensitization

Answer 15

Central sensitization

• Rewiring of the nerve connections centrally
• May be in part due to loss of descendung inhibition
• Activity levels in nociceptive afferents that were subthreshold prior to the sensitizing event become sufficient to generate action potentials in dorsal horn neurons contributing to pain sensitivity
• Allodynia
• Hyperalgesia

Question 16

In central sensitization, activity levels in ____ that were subthreshold prior to the sensitizing event become sufficient to generate action potentials in ____, contributing to pain sensitivity

Answer 16

In central sensitization, activity levels in nociceptive afferents that were subthreshold prior to the sensitizing event become sufficient to generate action potentials in dorsal horn neurons, contributing to pain sensitivity

Question 17

Central sensitization leads to ____, ____, ____, and ____

Answer 17

Central sensitization leads to heightened sensitivities across all the senses, cognitive deficits, increased anxiety, and sick role behaviors

Question 18

____ serves as a warning of potential or indicator of actual tissue damage and is a protective mechanism within the body

Answer 18

Perception of pain serves as a warning of potential or indicator of actual tissue damage and is a protective mechanism within the body

Question 19

Compare acute versus chronic pain

Answer 19

Acute vs. chronic pain

• Acute pain: occurs from injury or trauma, is signal to body that something is injured and needs to be healed, has expected duration of time, resolves once tissue recovers
• Chronic pain: continues past the time of healing for the initial injury, structural changes occur in peripheral nervous system and brain (plasticity), symptoms of unremitting and spontaneous shooting or burning sensations and abnormal sensitivity to normally noxius stimuli on exam

Question 20

Chronic pain involves messages that are ____ but become the focus of ____ and ____

Answer 20

Chronic pain involves messages that are no longer useful or protective but become the focus of impairment and limitation

Question 21

Pyschologic components of pain include ____ and ____ factors

Answer 21

Pyschologic components of pain include affective and cognitive factors

• Affective factors: depression, anxiety, anger
• Cognitive factors: catastrophizing, fear, helplessness, decreased self-efficacy, pain coping, readiness to change, acceptance

Question 22

Triad of ____, ____, and ____ leads to ____ in chronic pain

Answer 22

Triad of pain, depression / anxiety, and sleep disturbances leads to functional impairment in chronic pain

Question 23

Depressed patients perceive ____ pain

Answer 23

Depressed patients perceive more pain

Question 24

Acute pain is treated via the ____ mode, which states that ____

Answer 24

Acute pain is treated via the biomedical treatment model, which states that pain is a sensory event reflecting underlying disease or tissue damage

Question 25

Chronic pain necessitates a ____ model, which involves ____ including ____, ____, ____, ____, and ____

Answer 25

Chronic pain necessitates a biopsychosocial model, which necessitates interdisciplinary treatment including pain psychology, phyical therapy, occupational therapy, relaxation training / biofeedback, and vocational treatment

Question 26

____ is NOT a goal of treatment of chronic pain

Answer 26

Resolution of pain is NOT a goal of treatment of chronic pain