WEEK 2: Psychological aspects of pain Flashcards
What is pain?
The wordpaincomes from the old French peine, in turn fromLatin poena “punishment, penalty”
in Greek (poine)meaning price paid, penalty or punishment
Aristotle believed that pain was due to evil spirits entering the body through injury
Hippocrates believed that it was due to an imbalance in vital fluids
Physical pain as a political issue-black lives matter
Pain is a “sensory and emotional” experience (p.226; Merskey, 1986)
Medical community attempts to explain as either mental or physical
Medical community view is misleading for the patient
One’s perception of their pain results in many cognitive-emotional experiences
State the purpose of pain.
- Prevents serious damage.
If you touch something hot, you are forced to withdraw your hand before it gets seriously burnt. - Teaches one what to avoid
If pain is in joints, pain limits the activity
so no permanent damage can occur.
Butpain can become the problem and cause people to want to die
What is nociception?
Multistage process built on a complex anatomic network and chemical mediators that produce pain.
Nociception is the physiological process underlying pain.
State the 4 stages of nociception.
It can be divided into four stages
1. Transduction
2. Transmission
3. Perception
4. Modulation
Describe transduction stage of nociception.
This is the first stage of nociception
Converting a noxious or painful stimulus into a nervous impulse
Exposure to noxious stimuli stimulates nociceptors
These neurones are particularly tuned to respond to mechanical, thermal or chemical stimuli that are strong enough to cause or indicate tissue damage.
Describe the transmission stage of nociception.
State the 2 fibers responsible for transmitting pain signals.
Transmission involves the noxious stimuli being conducted by sensory nerves to the CNS then to the brain.
Action potential generated causes a nerve impulse to travel via sensory nerves to the spinal cord and on to the brain.
The main fibres responsible for this are C fibres and Ad fibres.
The connections in the Spinal cord are complex.
Describe transmission stage for a person stabbed with a nail on toe.
Stubbed toe
Initial fast impulse to brain along Ad -fibre
Causes sharp pain
Then travels via slower C- fibre
Therefore felt little later
Causes a dull aching more diffuse pain
Describe the perception stage of nociception.
Pain is perceived by an individual once all the incoming nervous messages are interpreted by the brain.
It is therefore influenced by a wide range of factors including
Social, psychological factors, Gender, Age, Culture
Previous pain experience
Emotional and environmental factors
This explains the following observations:
the same nociceptive inputs can be interpreted as different levels of pain by different people
or by the same person in different circumstances
or at different times.
Outline factors that influence pain perception.
Based upon summation of inputs
Awareness of seriousness of injury
Meaning of the injury
Present state of mind
Social, psychological factors, Gender, Age, Culture
Previous pain experience
Emotional and environmental factors
Discuss the role of different parts of the brain in pain perception.
Integration by thalamus & Hypothalamus
Integration by RF
Anterior Cingulate Cortex
Somatosensory cortex
Integration by limbic system
Integration by cerebral cortex
- RETICULAR FORMATION
The reticular formation is a group of neurons within the brain stem.
It has a major role in
-alertness
-fatigue
-motivation to perform various activities.
- Thalamus & Hypothalamus
The thalamus is of central importance to the sensation of pain.
A lot of pain information is relayed through the thalamus.
Fibres from the thalamus project to many sites
Connections to the hypothalamus are also important for the autonomic responses
Autonomic responses are observed when someone is suffering pain and they play a part in the assessment of pain
pallor,
sweating,
increased heart rate,
dilated pupils, increased blood pressure
Increased respiratory rate.
- LIMBIC SYSTEM
The limbic system is a collection of components rather than a specific area or part of the brain.
It is sometimes called the emotional brain.
The emotional aspects of pain and responses associated with it such as anxiety and fear are generated within the limbic system.
- CEREBRAL CORTEX
A number of areas in the cortex are associated with pain
They help us make sense of the pain
evaluate how serious it is
and to learn from our pain experiences. - SOMATOSENSOTY CORTEX
The Somatosensory enables us to understand
the location and quality of the pain
the magnitude of the stimulus
Discuss modulation step of pain perception.
Adjustment of nociceptive messages to increase or decrease pain experienced.
Various mechanisms involved; these include:
Descending inhibition
Peripheral mechanisms
External modulation
Central mechanisms
The pain signal in spinal cord ascends to the higher cortical centers of brain which evoke an emotional-reaction called:
One’s Perception of Pain
Discuss Assessment: Immediate Pain.
Intensity
Location
Affective Response
Composite Measures
Pain is always subjective. It is the result of a variety of factors. The assessment of pain, therefore, must rely on methods that are necessarily subjective and multidimensional. Currently there is no universal “gold standard” for pain assessment, and it is not the purpose here to outline a blueprint for such an assessment. However, any approach must acknowledge the many different dimensions of the pain experience. These dimensions are discussed in the following slides and include the areas bulleted above.
Discuss Assessment: Physical Function
Impairment
Functional limitations
Disability
Discuss Assessment: Psychological factors.
Influence vs. causation
Mediation
Reinforcement
Resonators
Pain beliefs
No pain should ever be viewed as either “physical” or “psychological.” Unfortunately, we often only look for the psychological factors contributing to pain after all biological contributors are ruled out. Psychological evaluation is important for any pain patient. It is important in predicting a patient’s outcome, and it may be more accurate in this than other more “objective” measures of a patient’s injury.
In performing a psychological assessment in a pain patient, we must look for any factors that may affect a person’s perception of pain, and subsequent response to the pain. Our goal is to find factors that influence pain, rather that cause it. It may be helpful to make these goals clear to the patient, who may be skeptical of psychological questions. Most patients will be defensive at the implication that the pain they experience is “just in their head.” They are usually quite willing, however, to consider how stresses in their life might influence their pain.
In that past, much attention was devoted to notions of particular psychological profiles that were more vulnerable to pain syndromes (the "pain-prone personality") however this has never been well validated. A proper assessment should include both the patient and other significant persons. A typical interview will examine number of psychosocial areas. We should try to identify events that exacerbate pain. Also, we should review a patient's usual daily activities, and appraise how these activities have changed because of the pain. We wish to learn how a patient copes with their pain. Possible sources of reinforcement of the pain, whether financial, sympathetic or avoidance-related should be tactfully explored. We should ask about past significant events, which may resonate with the current situation. For example, once study found that almost half of women presenting to a GI clinic who had a functional disorder (irritable bowel syndrome, chronic abdominal pain, or nonulcer dyspepsia) had a history of physical or sexual abuse. Similarly, we should look for family histories of similar pain problems. Any psychiatric illnesses, such as depression and anxiety, may affect pain, and we should ask about these. Finally, we should try to understand the patient's beliefs about the pain. Such beliefs can include beliefs about etiology, such as issues of retribution or blame. They may also include beliefs about outcome: one can imagine that patients will interpret a pain differently if they think it represents the progression of a serious disease. Standard instruments generally fall into categories of general psychological measurements and ones that are specifically designed to measure psychological factors in pain patients. The former are more widely used and accepted, but they may not have been well validated for pain patients.
Discuss Assessment: Pain Behavior
Observation
Role of learning
Besides the subjective pain experience, patients can exhibit predictable behaviors associated with their pain. These behaviors have the advantage of being readily observable. They are also reinforced over time–that is, they are learned behaviors. Most important, they represent potential targets for behavioral intervention.
Assessment of pain behavior is best done through observation, as patients may not even be aware of their behavior.
One can observe for verbal and nonverbal behavior associated with the pain experience. Examples of verbal behavior include complaining of pain, or using other vocalizations (e.g.., moaning). Nonverbal behavior can be general, involving movement (e.g.., pacing), position, or more specific (e.g.., guarding or rubbing a painful joint). Though different researchers emphasize particular behaviors as “more valid” indicators of pain, the behavioral expression of pain is probably very personal
