Pain Lecture Flashcards
Define pain.
Pain is “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage”. - International Association for the Study of Pain
What are the benefits of treating pain?
Physical -
- improved sleep, better appetite
- fewer medical complications (e.g. MI, pneumonia)
Psychological
- reduced sufferring
- less depression
Societal
- lower health costs e.g. shorter hospital stay
- able to contribute to society
*
How can you classify pain?
By duration
- Acute
- Chronic
- Acute on chronic
Cause
- Cancer
- Non cancer
Mechanism
- Nociceptive
- Neuropathic
Distinguish acute and chronic pain.
Acute - pain of recent onset and probable limited duration
Chronic - pain lasting more than 3 months; pain lasting after normal healing; often no identifiable cause
What are the differences between cancer and non-cancer pain?
Cancer pain - progressive. may be mixture of chronic and acute
Non-cancer pain - many different causes, acute or chronic
Non-cancer pain - fracture, appendicitis.
What is nociceptive pain? Describe it.
- •Obvious tissue injury or illness
- •Also called physiological or inflammatory pain
- •Protective function
- •Description
- –Sharp ± dull
- –Well localised
Describe neuropathic pain.
- Nervous system damage or abnormality
- Tissue injury may not be obvious
- Does not have protective function
- Description
- Burning, shooting and/or numbness, pins and needles
- Not well localised
Describe acute non-cancer pain. Give examples.
- E.g. fracture, appendicitis
- Symptom of tissue injury or illness
- Usually nociceptive
- Occasionally neuropathic (e.g. scaitica)
Describe chronic non-cancer pain.
- E.g. chronic back pain, arthritis
- Injury may not be obvious
- Complex, may be mixed nociceptive and neuropathic
- Does not respond to usual drug treatment
Descirbe cancer pain and give examples.
- E.g uterine cervical cancer, breast cancer
- Features of acute and chronic pain - may be acute or chronic
- Often mixed nociceptive and neuropathic pain
- Usually gets worse over time if untreated
Define allodynia.
Allodynia refers to central pain sensitization (increased response of neurons) following normally non-painful, often repetitive, stimulation. Allodynia can lead to the triggering of a pain response from stimuli which do not normally provoke pain.
Define hyperpathia.
Hyperpathia is a clinical symptom of certain neurological disorders wherein nociceptive stimuli evoke exaggerated levels of pain. This should not be confused with allodynia, where normally non-painful stimuli evoke pain.
Define hyperalgesia.
Hyperalgesia is a condition where a person develops an increased sensitivity to pain.
Define nociception. How does it differ from pain perception?
How signal get from site of injury to the brain
Vs pain perception - how we “feel” pain
Not the same.
How does nocicpeption lead to pain perception?
What are the 4 main steps in pain phsyiology?
- Periphery
- Spinal cord
- Brain
- Modulation
What are the main peripheral pain receptors?
A-delta C nerve fibres
Describe the physiology of pain in the periphery.
- Tissue injury
- Release of chemicals
- Stimulation of pain receptors (nociceptors)
- Signal travles in A-delta C nerves to spinal cord
Descirbe pain perception in the spinal cord.
- Dorsal horn is the first relay station
- •Aδ or C nerve synapses (connects) with second nerve
- •Second nerve travels up opposite side of spinal cord
How does meditation reduce pain?
Descending inhibition is increased
Describe pain perception in the brain.
- Thalamus is the second relay station
- •Connections to many parts of the brain
- –Cortex
- –Limbic system
- –Brainstem
- •Pain perception occurs in the cortex
How does modulation affect pain perception?
Descending pathway from brain to dorsal horn
Usually DECREASES pain signal