1. Understanding and Managing Pain
Chapter Seven
Understanding and Managing Pain

2. Five Questions This chapter focuses on five basic questions:
1. How does the nervous system register pain?
2. What is the meaning of pain?
3. How can pain be measured?
4. What types of pain present the biggest problems?
5. What techniques are effective for pain management?

3. Pain Pain - unpleasant feeling caused by illness or injury
Pain is important for survival

4. Pain and the Nervous System
Sense receptors located on the surface of the body turn physical energy into neural impulses
These neural impulses can travel to the peripheral nervous system toward the spinal cord and brain

5. Neurons
Afferent neurons - sensory neurons that relay information from the sense organs toward the brain
Primary afferents - specialized receptors in sense organs that convert physical energy into neural impulses and carry this information to the brain to be processed

6. Neurons Myelinated afferent neurons - neurons covered in myelin
A-fibers important in pain perception
Responsible for “fast”, prickly pain
C-fibers are unmyelinated afferent neurons
Responsible for slower, dull pain

7. Perceiving Pain Nociception - process of perceiving pain
Nocireceptors - receptors in the skin and organs that are capable of responding to various types of stimulation

8. The Spinal Cord
Spinal cord - pathway for ascending sensory information and descending motor information to and from the brain

9. The Spinal Cord

10. The Brain
From the spinal cord, the brain receives information from afferent neurons
Somatosensory cortex - part of the brain that receives sensory information that allows the entire surface of the skin to be mapped

11. Somatosensory Cortex

12. Neurotransmitters and Pain
Neurotransmitters - chemicals that are synthesized and stored in neurons
In the 1970s, researchers identified naturally occurring chemicals in the brain that affect pain perception
Endorphins, enkephalins, and dynorphin modulate pain
Glutamate, substance P, bradykinin, and prostaglandins produce pain

13. The Modulation of Pain
Periaqueductal gray - an area of the brain involved in modulation of pain
When this part of the brain is stimulated, pain relief occurs
Modulating pain may be important in some survival instances

14. The Modulation of Pain

15. Defining Pain Pain is due to two factors: The sensation
The person’s reaction to that sensation

16. Defining Pain Pain can be viewed in terms of three stages:
Acute pain - normally brief from a cut, burn, injury; adaptive in that it signals the person to avoid further injury
Chronic pain - endures over months; no adaptive reason or biological benefit
Prechronic pain - occurs between acute and chronic pain

17. Experiencing Pain
The experience of pain is individualized, subjective, situational, and cultural
Individualized differences in pain
Cultural differences in pain
African Americans and Hispanic Americans show higher sensitivity to pain than European Americans

18. Experiencing Pain Gender Differences in Pain Perception
Women report pain more readily than men
May be due to gender roles and socialization

19. Theories of Pain
The first theory of pain was the specificity theory; however, this theory is too simplistic
Currently, the gate control theory of pain is used to understand pain

20. Gate Control Theory of Pain
Gate Control Theory of Pain - pain perception is subjected to a number of modulations that influence the experience of pain
Structures in the spinal cord as a gate for the sensory input that the brain interprets as pain

21. Gate Control Theory of Pain

22. Gate Control Theory of Pain
Gate Control Theory also suggests that pain has motivational and emotional components
Gate control trigger - nerve impulses that descend from the brain and influence the gate mechanism
For example, distraction or relaxation could cause the gate to close, causing a decrease in pain

23. The Measurement of Pain
Pain can be measured in a number of ways:
Self-report ratings
Behavioral assessments
Physiological measures

24. Self-Reports
Self-reports ask people to evaluate and make ratings of their pain using:
Rating scales, such as the Visual Analog Scale, where people rate their pain
Pain questionnaires, where people are asked to make certain distinctions about their pain
Standardized psychological tests, where dishonesty about pain can be assessed

25. Behavioral Assessments
Behavioral assessments of pain use observation of the patient to assess pain
Record body movements and facial expressions looking for signs of pain
This method may be especially useful for children and elderly who may not be able to accurately self-report on pain

26. Physiological Measures
Electromyography (EMG) - measures level of muscle tension, as pain may increase tension
Heart rate - predicts perception of pain, but only for men
Overall, physiological assessments may not be as valid as self-report or observational methods

27. Pain Syndromes
More than 30% of people in the US experience chronic or intermittent persistent pain
Chronic pain is categorized as a syndrome - symptoms that occur together

28. Headache Pain Headache pain
Most common of all types of pain; 90% of people will experience headaches
Three primary types of headaches:
Migraine headaches
Tension headaches
Cluster headaches

29. Low Back Pain Low back pain
Approximately 80% of people will experience low back pain
Injuries, pregnancy, infections, degenerative diseases, and malignancies all can cause lower back pain

30. Arthritis Pain Arthritis Pain
Rheumatoid arthritis - an autoimmune disorder characterized by swelling and inflammation of the joints
Osteoarthritis - progressive inflammation of the joints; affects mainly older adults
Fibromyalgia - characterized by tender points throughout the body; not considered arthritis

31. Cancer Pain Pain is present in 44% of all cancer cases
Almost half of all cancer patients’ pain is left untreated

32. Phantom Limb Pain
Phantom Limb Pain - the experience of chronic pain in a part of the body that is missing
Reports vary but it may be that 90% of amputees experience phantom limb pain
Pain is more likely to occur when a person experienced much pain before the amputation
There may be an emotional basis to this pain but also the CNS and PNS may make maladaptive adaptations after the amputation

33. Managing Pain Treatment for pain varies
Acute pain is easier to treat as the source of the pain is clear
Chronic pain is more difficult because there is not usually an obvious source
Relief can be sought by two methods:
Medical approaches
Behavioral management approaches

34. Medical Approaches
One of the most common medical approaches is the use of drugs
Analgesic drugs - relieve pain; most likely to be opiates or nonnarcotic analgesics
Limitations to using drugs to treat pain:
Tolerance and dependence on drugs
Overmedication

35. Medical Approaches
Another medical approach used to manage pain is surgery
Surgery aims to repair the source of the pain or alter the nervous system to alleviate the pain
Limitations of surgery:
It may not always repair damaged tissue
It may not provide patients with relief
Expensive

36. Behavioral Approaches
Several behavioral approaches have been used to help manage pain:
Relaxation therapy
Behavioral therapy
Cognitive therapy
Cognitive-behavioral therapy

37. Relaxation Therapy
Relaxation Therapy - systematic tensing and relaxing of muscles
used successfully to treat tension and migraine headaches, rheumatoid arthritis, low back pain

38. Behavioral Therapy
Behavioral Therapy/behavioral modification - process of shaping behavior through the application of operant conditioning principles
Removal of reinforcers that may have been prompting “pain traps”
Has been effective in decreasing pain intensity and improving quality of life

39. Cognitive Therapy
Cognitive Therapy - based on the principle that people’s beliefs, personal standards, and feelings of self-efficacy strongly affect their behavior
Identify irrational thoughts or “catastrophizing” and eliminate or change them

40. Cognitive Behavioral Therapy
Cognitive Behavioral Therapy (CBT) - type of therapy aimed at developing beliefs, attitudes, thoughts, and skills to make positive changes in behavior
One form of CBT is acceptance and commitment therapy (ACT) which encourages acceptance of pain by focusing attention on other valuable goals and activities

41. Effectiveness of Therapies