Thangamani ramalingam PT, MSc(PSY),PGDRM, MIAP

syllabus

Pain psychology (briefly) [2 Hours]a) Define pain, physiology of painb) psycho – social factors of painc) pain management (Psychological methods)

Pain

“An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage” ISAP (1979)

One of the most common health problems that causes people to seek medical attention

Pain is actually beneficial to long-term health and survival

DEFINITION Pain is a noxious unwanted perception in which

the patient seeks medical intervention. “Pain is subjective, individual and modified by

degrees of attention, emotional state and the conditioning of past experiences.” (Livingstone 1943). The intensity of the pain is not directly proportional to the degree of suffering. Because it is basically a psychological experience and depends on how it is interpreted or experienced

TYPES Acute pain – shorter duration up to six months

Acute monophonic pain Recurrent acute non-malignant pain

Chronic pain – longer duration > six months Chronic malignant pain - progressive Intractable-benign Chronic pain associated with non-malignancy disease – identifiable

pathology Chronic non-malignant pain syndrome Recurrent acute – migraine

Chronic and acute pain may have different causes – behavioral factors may be involved in acute pain

PAIN RECEPTORS

PHYSIOLOGY OF PAIN

Influenced by Limbic system & Reticular formation

Gate Control Theory

Gate control theory –Melzack & Wall (1965) severity of pain sensation determined by balance between excitatory and

inhibitory inputs to T cells in spinal cord C & A-delta nociceptor afferents give excitatory input to dorsal root

ganglion of spinal cord– A-delta (myelinated) about 40 mph and C fibers (unmyelinated) about 3 mph, other sensory information travels at about 180 -240 mph

Substantia gelatinosa, large diameter A-beta non-nociceptor afferents give inhibitory input

Increased firing of non-nociceptor afferents causes presynaptic inhibition of T cells and the spinal gate from excitatory cells to the brain is closed. –

Physical agent modalities and physical activities believed to close the gate by activating the non-nociceptor afferents

Central Control Mechanisms of Pain

Theories of pain Pain gate theory (Melzack& Wall) Pattern theory (Sinclair) Chemical theory (Neurotransmitters) (Encephalin /β-

endorphins) Descending control theory (PAG /Raphe nucleus

Inhibition) Substance ‘P’ levels Serotonin levels Central Control Mechanisms (by brain) Specific theory (Unique theory)

The same part of the brain – the anterior cingulate cortex – responds to physical and emotional pain.

Pain in the brain

Chemical processes involved in pain

Substance P Chemical mediator thought to be

involved with transmission of pain.Associated with inflammatory painIt excites pain transmitting neurons

when releasedIts mechanism is not fully

understood Glutamate – release affects

amount of pain experienced

Prostaglandins, bradykinin – released when tissue damaged

Chemical processes involved in pain Endorphins

Pain perception modulated by these opiate like neurotransmitters

The endorphins bind to certain sites on the nervous system including peripheral nerves

They suppress pain transmission at the spinal cord level by inhibiting the release of the neurotransmitter gamma aminobutyric acid (GABA) in the periaqueductal gray matter (PAGM) and raphe nucleus of the brain

High concentration of opiate receptors in limbic area of brain explains the stress relief and euphoria associated with opiates

Limbic system involved with emotional component of pain

Pain assessment

Physiological measuresEMG – muscle tensionHeart rateSkin temperatureEEG and brain imaging

Behavioral pain measuresPhysical symptomsClusters: guarding, bracing, rubbing, grimacing, and sighingSymptoms can be misrepresented: report and unobtrusive

observation differences – Kremer et al. (1981)Self-report measures

McGill Pain Questionnaire - sensations- feelings- intensity

Pain Rating Scales

Visual Analog Scale(VAS)Graphic Rating Scale(GRS)Simple Descriptor Scale(SDS)Numerical Rating Scale(NRS)Faces Rating Scale(FRS)

Pain Rating Scales

Pain Discomfort Scale

Chronic)

Injury / Insult

Treatment

Failure of Treatment

Loss of Control

Dependence

Reliance on Medication

Pain

Psychological & SocialConsequences

Adapted from Gill (1997)

Pain Cycle

FACTORS AFFECTING PAIN Physical Factors: Pain tolerance Body constitution / Genetics Age Sex Temperature Climate (Humidity, Cold, Winter) Light, darkness Noise level Avoidance of physical activity

Social Factors: Relationship with family Social Norms Politico-Judicial Factors Cultural effects (occupation, Social interactions Hobbies

Psychological Factors: Personality (Introvert / Extrovert) Social Context or role (e.g. – Soldier vs Civilian) Attention Ecstasy Attitudes, past experiences Anxiety /

Depression Learning / Memory (Education) Dependency / Conditioning Avoidance behavior Judgment, Ego, Expectation

Psychological factors

Learningmodelingsecondary gain financialculture

Personalityanxiety and depressive disordersextroversion is associated with higher

pain thresholdsinternal locus of control is associated

with better coping

Cognitionanticipation of pain is often

worse than pain itselfexpectations of their ability to

cope coping strategiesStress

Sixteen Pain Behaviors

Asymmetry Slow response time Guarded movement Limping Bracing Personal contact Position shifts Partial movement

Absence of movement Eye movement Grimacing Quality of speech Pain statements Limitation statements Sounds Pain relief devices

(under use)

Physical methods for controlling pain

Medications

Opioid analgesics: substance P release into dorsal horn regulated by endogenous endorphins and exogenous opioids.

Inhibit substance P release

Medications

MorphineOxyContinSynthetics opiatesLocal anesthetics

Medications

NSAID’s - Non-steroidal anti-inflammatory drugsAspirin, ibuprofen, naproxen,

phenylbutazone, ketoprofen, diclofenac

Acetaminophen (Tylenol)has analgesic and antipyretic (fever

reducing) effect, but no anti-inflammatory effect

Surgery

muscle/ nerve repair

Physical methods

Physical therapy

Exercise

Counter irritation – irritating body tissue to ease pain

Transcutaneous electrical nerve stimulation (TENS)

Acupuncture –

Massage therapy

Chiropractic therapy

.

Psychological methods for controlling pain

HypnosisBiofeedbackRelaxation and

distractionCognitive - Behavior

therapyBehavioral Medicine

Behavioral/Cognitive Approaches

• Distraction Music and pain reduction –

Anderson et al. (1991)

• Relaxation• Progressive technique• Autogenic technique – use of self

instructions of warmth and heaviness

Behavioral/Cognitive Approaches

• Guided Imagery • Systematic

desensitization• Reframing• Meditation• Stress management

techniques – not as effective as other techniques

• Thinking about the pain and expectations

Placebo

Classical conditioningPatient’s may change behaviorsPhysiological changes which inhibit the

experience of pain