Pain Mechanisms Flashcards
What is acute pain?
“An unpleasant sensory or emotional experience
that is associated with actual or potential tissue
damaging stimuli”
It occurs due to a specific injury/tissue damage. It is self-limiting and ceases once healing occurs.
What is the specificity theory?
A stimulus causes a response. There is a direct link between the cause of pain and the signal to the brain resulting in sensation. It argued that the body has separate sensory systems for touch, heat, cold and pain etc.
What is the problem with the specificity theory?
It ignores the individual aspect of pain, effects of emotion on pain, the effect of distraction/attention, beliefs, etc.
What is the gate-control theory?
Physiological mechanisms for ‘psychological’ effects on the experience of pain. Neural gate can open and close for pain control. This ‘gate’ is located in the spinal cord.
Chronic pain affects how many % of adults?
How long does it take to get adequate control?
25%
Up to 2 years
What is chronic pain?
A continued state of suffering. Pain that persists past
the healing phase following an injury.
The persistence of the memory of pain and/or the inability to extinguish the memory of pain evoked by an initial inciting injury.
What is the pain triumvirate/what are the three components?
- Sensory/discriminative – localisation in time/space, assessment of intensity. Lateral thalamic nuclei.
- Affective/motivational – emotional/unpleasant aspect of pain, reward in escape. Basal ganglia, medial thalamic nuclei, anterior cingulate cortex, insula.
- Cognitive/evaluative – interpretation of pain and its meaning. Anterior cingulate cortex.
How does the pain triumvirate differ in acute and chronic pain?
In acute pain, sensory component is dominant.
In chronic pain, affective component is dominant.
Dysfunction in which circuits causes depression/anxiety and chronic pain? (4)
Serotonin, noradrenaline, opioid, dopamine
What is the role of serotonin and noradrenaline?
Supress sensation of normal bodily functions
What is the role of dopamine?
Application of importance and focuses attention, dampens pain
What is the role of the opioid system?
Prevents spread of pain, dampens pain, reinforces behaviour
What may the pain in depression also be due to? (4)
Autonomic nervous system dysfunction
HPA axis dysregulation
Abnormal activation immune system
Genetic association
What are the four types of pain behaviours?
Negative affect, facial/audible expression of distress, distorted ambulation or posture, avoidance of activity
What is pacing?
A combination of pain and activity avoidance, a hidden form of avoidance behaviour.
