understanding and managing pain. insensitivity to pain = many injuries
TRANSCRIPT
Understanding and Managing Pain
Insensitivity to pain = many injuries
Somatosensory System
• Moves info. From body to brain
Neurons
• Afferent (sensory) neurons
• Interneurons - Connect sensory neurons to motor neurons
• Efferent (motor) neurons
Somatosensory cortex
Brain Scans
• PET
• fMRI
Pain
Definition of pain
• Sensation + emotional reaction to sensation
Types of pain• Acute
– Occurs when injured - cut, burn, childbirth, surgery– Adaptive– Warns of further injury
• Chronic– Lasts months or years– Not adaptive– No biological benefit– Reinforced by environmental factors
• Sympathy
– It is still real pain
The experience of pain
• Anzio beachhead– Carrying severed arm– People not realizing they were shot
Expression of pain
• Cultural background & social context – E.g. Childbirth– Rites of
passage
Theories of pain
Specificity theory of pain• Pain = amount of tissue damaged
– Pain largely uninfluenced by psychological forces
• Problems– No specific skin receptors devoted to relaying pain– Phantom limb pain– Injury without pain
• E.g. in war
Gate control theory of pain
• Sensory input is not the only factor in pain perception– Changes in the spinal column and brain
control the flow of neural impulses– Parts of spinal column can either
• increase (open the gate) or • decrease (close the gate)
Measurement of pain• 1. Self-report
– Rating scales (e.g. 0-10)– MMPI
• 2. Behavioral assessments– Observing a patient’s behavior
• 3. Physiological measures– Electromyography (EMG)
• Muscle tension• Not a very good method (Poor validity)
Phantom limb pain
• Common following amputation
• Decreases with time
Managing pain with medicine
• Self-paced administration of narcotics– E.g. morphine pump
• Limits are programmed in
– Avoids undermedication– Patients use less medication– Higher satisfaction
Managing pain with behavior
• Relaxation training– Reduces
• Headaches• Rheumatoid arthritis• Low back pain
• Behavior modification– Based on operant conditioning– Positive reinforcers for pain - e.g. sympathy
• Increase pain
– Reinforcing desirable (non pain) behavior• Reduces pain
Managing pain with behavior
• Cognitive behavioral therapy (CBT)– Changing your thinking patterns– E.g. “Reframing” - “Pain is weakness
leaving the body” - Used in the military