Psychobiology Of Pain (Year 3) Flashcards

Question

Describe the structure of the spinothalamic tract

Answer 1

- lasts under three months - adaptive - signals tissue damage and helps protect from further damage - initiating event is known (injury, infection etc.) - pain subsides with successful treatment of original injury

Answer 2

- labor pain - injuries (e.g from sports, work) - dental surgery

Answer 3

- post-operative pain - post-traumatic pain - burn-injury pain

Answer 4

1. emergency phase 2. healing phase 3. rehabilitation phase

Answer 5

- from the time of injury to stabilisation of the patient - nociceptive pain originating from damaged tissues - anxiety and fear are imminent - psychological intervention: reassure, give information

Answer 6

- lasts weeks or months - background pain -- fluctuating, sometimes breakthroughs of pain - procedural pain due to wound cleaning or mobilization/physio danger of PTSD - counselling intervention - patient may need to discuss feelings about body image/loss of body part

Answer 7

- deep aching pain - pain becomes regional - treatment may include acupuncture, hypnosis etc.

Answer 8

- induced pain and primary and secondary hyperalgesia lasting 2-7 days - release of prostaglandins, histamine, bradykinin, substance P + others that sensitize nociceptors

Answer 9

- Segmental, spinal cord reflexes leading to muscle contractions/spasms (increased consumption of oxygen). This also increases lactate in the blood. - Stimulation of the sympathetic nerve system (tachycardia, blood pressure, cardiac work, and a decreased tone of the smooth muscles in gut and urinary system) - Release of stress hormones: cortisol, adrenaline, insulin. (part of fight or flight - can inhibit pain in the short-term)

Answer 10

- pain is related to tissue damage and therapeutic interventions - tissue damage - skin burning and direct exposure of nociceptors in severe pain - burn pain associated with depression and PTSD

Answer 11

- wound cleaning, skin stretching, skin transplants, plastic surgery, mobilisation - pain sustains in spite of intravenous administration of opioids

Answer 12

- pre-injury status is important - 25-75% of patients report depression, substance abuse and suicide attempts prior to injury implications - drug-abuse patients may show decreased tolerance to pain - more drug-seeking behaviour and greater tolerance to opioid treatment - people with personality predispositions may should aggressive behaviour and low frustration threshold - negative emotions worsen pain (anxiety, depression) - PTSD likely to develop

Answer 13

- the patient may re-experience the event (thoughts, images, flash-backs etc.) - ptsd patient avoids situations and conversations associating with event and may have some memory loss for event - associated with higher physiological arousal - sleep distrubances, hypervigilance, difficulty concentrating

Answer 14

- pain lasting 3 months or more

Answer 15

- painful polyneuropathies - low back pain/ failed back surgery syndrome - CRPS - phantom pain

Answer 16

- arthritis - fribtomyalgia

Answer 17

- irritable bowel syndrome - burning mouth syndrome

Answer 18

- pain caused by a lesion or disease of the somatosensory system

Answer 19

- toxic-metabolic (endocrine, chemotherapy) - post-traumatic (e.g CRPS type ii) - compressive (nerve entrapment e.g carpal tunnel) - autoimmune (e.g HIV) - infections )e.g herpes-zoster ->post herpetic neuralgia

Answer 20

- receptor sensitisation due to accumulation of neurotransmitters - upregulation of Na+ channels leading to increased neuronal excitability and hyperalgesia

Answer 21

- If a nerve is injured (cut), the proximal end seals off (end-bulb), swells, and within hours starts sending new connections to the distal end = sprouts. - If sprouts are able to connect (e.g., under blunt pressure, cooling) with the loose end, the function will be restored, no pain. - If sprouts are unable to connect, sprouts will end blindly in tissues and together with end-bulbs create a tangled knot = nerve-end neuroma. There can be sprouts trapped by tissues along the course of axon -> microneuroma.

Answer 22

- Sprouts are never myelinated, have unstable membrane potentials and therefore, can be excited by a variety of stimuli; they also may show spontaneous firing patterns = ectopia. - Increased expression of Na+ channels and instability of membranes leads to ectopia

Answer 23

1. End-bulb and sprouts in injured afferent axon. Myelin sheet is lost about 250 um before the end-bulb. 2. The end-bulb shows accumulation of Na+ ion channels.

Answer 24

Hot spots on nerve-end neuromas show electrical hyperexcitability - spontaneous firing in absence of stimuli. - prolonged firing beyond the duration of stimulation (after-discharges) C-fibre ectopia: firing at 0.1–10 Hz, increased by cooling, alleviated by warming. Ad fibre ectopia: firing at 15 - 30 Hz, increased by warming, decreased by cooling.

Answer 25

- chemical agents associated with tissue damage - inflammation and immune factors (e.g., interleukins) - noradrenaline released from sympathetic nerve endings - mechanical stimuli (pressure)

Answer 26

1. Presence of spontaneous pain which does not fade away during nights. 2. Decreased or increased thresholds for heat, cold (hypo/hyperalgesia). 3. Dynamic-mechanical and punctuate hyperalgesia 4. Temporal summation: abnormal painful sensations after repetitive non-painful stimulation (wind-up). 5. After-sensations: painful or unpleasant sensation continues beyond the stimulus duration. 6. Paresthesia – abnormal and unusual sensations that are described as neither unpleasant nor painful (tingling). 7. Dysesthesia – abnormal sensations described as disturbing and unpleasant; spontaneous or evoked. Other symptoms: hypotonia, sometimes incoordination or apraxia

Answer 27

As the name suggests, the syndrome belonging to this group would involve damage to peripheral nerves and that a widespread network of nerves will be involved, and is typically caused by disease rather than injury. - Can affect multiple/ networks of nerves - Most common is diabetic painful neuropathy

Answer 28

- Advanced or untreated diabetes mellitus is associated with symmetric distal polyneuropathy of both small and large nerve fibres. - Destruction of nerve fibres is attributed to decreased vascular blood supply to the lower extremities and axonal degeneration, and to accumulation of sugars such as sorbitol. - Pain is deep aching, burning. - Common in extremities

Answer 29

- Inflammatory neuropathy caused by Epstein-Barr virus. The syndrome is also associated with motor weakness sometimes leading to necessity of ventilatory support. - Removes myelin from nerves - Pain occurs in 40-75% of patients with G-B syndrome. - Pain is burning, and occurs in the back and legs. Frequent allodynia.

Answer 30

- Multi-system disorder affecting peripheral nerves, kidneys and skin. - It is an X-linked recessive gene disorder manifesting in lack of one lysosomal enzyme (alpha-galactosidase). - Pain is constant, burning, occurs in hands and feet. Pain can be controlled by antiepileptic and anticonvulsive drugs.

Answer 31

- beriberi - beriberi is due to B1 (thiamin) hypovitaminosis, which results in disease of nerves and cardiac muscle. - Symptoms: progressive weakness, paresthesia, dull or lancinating pain usually in distal limbs. - Treatment with B1 vitamin leads to recovery.

Answer 32

- HIV - HIV is associated with peripheral neuropathy due to vascular deficiency and de-myelination (autoimmune reaction). - Patients suffer from burning pain and dystesthesia especially in feet.

Answer 33

- impaired sleep - increased depression - anxiety

Answer 34

- Pain in the lower back, buttocks and thighs (may shoot into legs). - LBP comes in attacks which last weeks, however, it may become chronic. - LBP approaches epidemic numbers: 80% of adult population in USA, and about 40-60% in other developed countries report occurrence of LPB during lifetime. Disability due to low back pain is 2-5% in USA.

Answer 35

- heavy manual work, bending, twisting - cigarette smoking - age - sedentary jobs and being overweight Cigarette smoking and LBP: >50% of LBP patients are regular smokers: direct effects of nicotine on vasculature of the spine? coughing in smokers may increase the load on the vertebral disk?

Answer 36

- Chronic pain in the back and/or leg after a technically successful surgery of the vertebrae, vertebral discs, or spinal cord. - FBSS has an iatrogenic component because it develops after a technically successful surgery. - Pain is shooting, burning, frequent allodynia.

Answer 37

- mechanical damage of the dorsal root(s) – nerve fibres outside the spine - thickening of the dura mater (a membrane enveloping the spinal cord), which compresses the dorsal root - The condition cannot be treated with another surgery because the dura mater only gets thicker with each new surgery. Therefore, patients with failed back surgery syndrome are often treated with a spinal cord stimulator: electrical currents to the spinal cord and the medial pain system, which opposes the transmission of nociceptive impulses.

Answer 38

Older taxonomy: 1. Reflex sympathetic dystrophy 2. Causalgia (caustos = heat) Reflex sympathetic dystrophy Focal vasomotor abnormalities Pain, changes in vasomotor tone and skin colour Trophic changes (skin, hairs, nails) No obvious nerve damage Causalgia: often occurs in war injured people due to damage of peripheral nerves Burning pain in the territory of the affected nerve Intermittent temperature changes Changes in skin colour 1993: Complex Region Pain Syndrome

Answer 39

- previously reflex sympathetic dystrophy - presence of initiating noxious event (wound, fracture, inflammation) - continuing pain, allodynia, hyperalgesia, swelling, changes in blood flow and skin temperature more than 1.1 °C relative to homologous part of the body

Answer 40

- presence of injury of a major nerve trunk - presence of continuing pain, allodynia or hyperalgesia after nerve injury - evidence of some time swelling and/or change in skin temperature more than 1.1°C relative to homologous part of the body

Answer 41

- Hypofunction of the sympathetic nerve fibres – this leads to the upregulation of adrenergic receptors in peripheral nerve fibres. Effects change over time: - in acute phase (<6 months), the affected limb is warmer than the non-affected limb due to diminished sympathetic tone - chronic phase (>6 months) –vasoconstriction, cold, bluish extremity in the chronic period: role of circulating adrenaline, causes sensitisation to nociceptive stimuli Protective disuse - patient avoid tactile sensations and movements which aggravates pain: - accumulation of catecholamines in the limb - lack of natural somatosensory stimulation leading to vasomotor and central disturbances, decreased functionality of the limb (e.g., range of motion)

Answer 42

- Not related to age, women have larger prevalence of CRPS than men (3:1). - Type of injury: trauma, operation, inflammation, infectious disease, some drugs (e.g., anti-tuberculosis drugs). 4-7% of patients with a limb fracture or surgery develop CRPS. - Risk factor: immobilisation for a long period of time increases the likelihood of CRPS (protective disuse), e.g., rats whose limb has been immobilised for three weeks showed signs of allodynia. - Prognosis can be good if treatment starts soon after injury and before the pain spreads to the rest of the limb. Patients with CRPS requires an early treatment to have a chance of recovery

Answer 43

Chronic neuralgic pain occurring after infection by Herpes varicella zoster virus (chickenpox). (Herpes = something creeping (gr.); zoster = belt) Varicella virus gains access to the sensory nerves in the skin and passes to the dorsal root ganglion cells. It is re-activated when immune mechanisms fail (age, stress, illness). In acute phase, vesicular eruptions (rash) of the skin associated with inflammation of the deeper skin layers (shingles). The lesion cures by crusting and often leaves hypopigmentated areas. Neuropathic pain is severe, occurs only in the affected dermatome, but normally subsides with treatment.

Answer 44

Types of pain: 1. Background: steady, burning and aching pain 2. Sudden/brief: lancinating, paroxysmal pain Pain aggravated by touch; clothes may cause unbearable pain (dynamic-mechanical allodynia). Pain is of variable intensity but 40% of patients report intractable pain. Chronic pain is associated with depression and reduction of daily activities.

Answer 45

Age: almost 75% of people above 70 years are likely to develop chronic pain after HZ infection. Pain severity in acute phase correlates with the probability of having chronic PHN. Rash severity: number of vesicles and the size of rash area Sensory dysfunctions, such as increased tactile/vibration thresholds, in the acute phase, are associated with chronic form. Greater T-lymphocyte (cell) immunity response in acute phase is associated with chronic form of the syndrome.

Answer 46

- Pain felt in a nonexistent, amputated limb. - Pain varies from mild to excruciating, occurs in up to 80% of amputees - Prognostic factors: strong pre-amputation pain, being female, upper limb. - Other phantom sensations: (1) kinesthetic, positional (2) kinetic, motions (3) exteroceptive (cutaneous sensations) - Stump pain is felt in the region of amputation in the existing part of the body (10-25% of amputees)

Answer 47

- Phantom pain may last decades and then suddenly disappear, and re-appear again spontaneously. - Phantom pain initially involves the whole limb, later it “telescopes” to the stump. Quality of pain - Variable (gnawing, burning, cramping, aching, crushing, shooting). - Distal parts of the limb are more often the sites of phantom-limb pain. - The amputated limb is felt to be in a twisted or cramped position during periods of pain (patients report their nails being pulled from the nail beds).

Answer 48

Refractory to pharmacological treatment, however, promising results with motor imagery and mindfulness meditation. Emotions, stress, lack of sleep, and autonomic events increase phantom limb pain.

Answer 49

(1) Displacement, distension, inflammation of cranial vascular structures including carotid and intracranial arteries. (2) Sustained skeletal muscle contractions in the neck and head. (3) Direct pressure on cranial and upper cervical nerves.

Answer 50

Types of headaches: 1. Migraines: a) without aura, b) with aura 2. Cluster headache 3. Tension-type headache

Answer 51

Migraine headaches occur with or without aura (prodrome). Migraine is an idiopathic chronic pain disorder manifesting in attacks lasting 4-72 hours. Pain is pulsatile (throbbing) and usually unilateral, associated with nausea/vomiting, photophobia (light sensitivity) and phonophobia (sound sensitivity). Migraine pain is aggravated by physical exercise. Migraine is more frequent in women compared to men (3:1). One third of patients is severely disabled during migraine attacks.

Answer 52

Aura and pain: caused by vasospasms producing ischemia; the ensuing acidosis leads to vasodilation and pain – pulsatile quality of pain supports the view of a vascular origin of migraine pain Forms of aura: visual disturbances, images of stars or sparks or zig-zag lines (suggests that the occicipital cortex is at the beginning of the attack), unpleasant smell, confusing thoughts. Aura lasts about about 20 min and transforms into pain or a temporary normal period.

Answer 53

Prevalence: 1-year prevalence about 12% in developed countries the largest occurrence of migraine headaches are between 40-45 in females and 25-55 in males

Answer 54

A patient with migraine headaches without aura showed increased activation in the brainstem. The brainstem can initiate vascular changes leading to a migraine attack

Answer 55

Symptoms: - strictly unilateral, excruciating, rapid onset and offset - unilateral, however, the sides can swap - pain lasts for 45-90 min (“bout” of cluster headache); occurs from 1 to 8 per day - headaches are recurrent with a striking rhythmicity (circadian, circannual) - not aggravated by physical activity, no nausea associated with lacrimation, ptosis, restlessness, agitation - attacks are preceded by yawning and tiredness

Answer 56

3-7 times more frequent in females than in males (the female-male ratio changed in favor of females in past few decades) about 10% of patients develop a chronic cluster headache without periods of remission

Answer 57

Symptoms: - bilateral head pain, non-pulsatile, tightening mild to severe intensity, can be disabling for the duration of attack - not aggravated by physical activity, no nausea - head muscle tone increased, myofascial tenderness

Answer 58

- >60% life prevalence, becomes chronic form in 3% of population - peak of TTH is between 30-39 years - educational level is positively associated with TTH - Caucasians have greater prevalence of TTH than African Americans

Answer 59

Stress: periods of stress may induce headache attacks. Sleep: headache patients report poor sleep, insomnia, wake up unrefreshed. Sleep apnea syndrome contributes to headaches. Hormones: abrupt fall of estrogen level (pre-menstruation, menopause) is associated with headaches. Administration of estrogen-based contraceptives may also initiate an attack of headaches. Diet: sparse data. Chocolate in some individuals may probably trigger headaches. Alcohol evokes attacks of cluster headache within an hour.

Answer 60

Painful disease of older age (usually occurs at the age 50-70) with slight preponderance in women. Etiology: compression of the trigeminal nerve (5th cranial nerve), usually by the superior cerebral artery. Pain is electric shock-like, stabbing and unilateral, and paroxysmal (lasting from seconds up to 2 min). Patient’s face can get distorted (“freeze”), patient may cry Pain is elicited by a trigger: chewing, touch, talking, swallowing, therefore patients may lose weight by avoiding eating. Allodynia - patients may stop washing their teeth/face or shaving Treatment success is good with decompressing the nerve

Answer 61

usually as the result of trauma to the spinal cord. Often associated with phantom sensations from regions below the level of injury.

Answer 62

- Lesions in the CNS - Spinal cord lesions, brain lesions

Answer 63

stroke (bleeding) leading to the damage of thalamus, brainstem, subcortical white matter (e.g., spino-thalamic tract) and cortex

Answer 64

1. Spontaneous and steady pain (e.g., aching, cramping, crushing, burning). 2. Spontaneous neuralgia (shooting pain). 3. Allodynia. Pain seldom subsides by itself, but its quality changes over time.

Answer 65

Thalamic syndrome (central post-stroke pain): a lesion usually in contralateral thalamus but also in medulla or elsewhere. Wide range of pain qualities (e.g. burning, tearing, icy, pricking, or cutting). Multiple sclerosis (focal demyelination in the CNS) due to inflammation related to an auto-immune reaction – burning and aching pain. Pain is often the first sign of the start of MS. Syringomyelia - a cyst filled with fluids in the spinal canal compressing nerves and tracts, causes bilateral pain in arms, shoulders, and thorax

Answer 66

- Syndrome of unknown etiology associated with upper and lower body symmetrical musculo-skeletal pain, and with painful tenderness. - Pain is in soft tissues around joints capsules and periosteum (tendons, bursae, muscles) - Prevalence in general population 1-4%, 4×females

Answer 67

1. Persistent, widespread pain (aching, throbbing, stabbing) in soft tissues. 2. Widespread allodynia. Tender points: 18 points on the body are tested using a standardised pressure of 4kg/1cm2 , - having tenderness in 11 out of 18 points supports the diagnosis of FMS. Other symptoms: Morning stiffness – lasts 45 min – 4 hours, and associated with pain. Irritable bowel syndrome. “Fibro fog”: fatigue, headaches, dizziness, double vision, cognitive impairment (e.g. memory loss), insomnia. Depression Hypervigilance to pain: vigilance to somatosensory (non-painful) stimuli is higher in FMS than in controls: patients scan their bodies for somatic sensations.

Answer 68

FMS patients show shrinkage of the brainstem and reduction of brainstem volume which correlates with their sensitivity to pressure

Answer 69

Pain related to malfunction at the join osteoarthritis rheumatoid arthritis gout

Answer 70

Progressive loss of articular cartilage leading to joint pain and limitation of movement. OA present in 50% people > 75 years; obesity is a risk factor. Pain is aching, occurs mostly during movement. Stiffness of the joint is a frequent sign. At later stages, pain may sustain during sleep, and later even in the resting periods following activity.

Answer 71

Inflammatory polyarthritis, various joints in a symmetric fashion. Joints are swollen, tender and warm. RA often caused by an increased autoimmune response. Other symptoms: fatigue, loss of weight, subfebrilia, morning stiffness. Females show 3× larger prevalence of RA than men.

Answer 72

Metabolic disease associated with increased serum level of urate ions that accummulate in the joint and eventually destroy the cartilages. Pain often occurs in the metatarsal joint of the great toe (podagra). A gout attack starts in early morning hours, and peaks after 24 hours. The joint is red and swollen. One attack lasts about two weeks.

Answer 73

Unpleasant, painful sensations in the abdomen associated with frequent stool, abnormal stool form, and/or abnormal stool passage. More prevalent in females than males (2-2.5 : 1), usually occurs at the age of 30-50 years. IBS is frequently associated with fibromyalgia, and with psychiatric syndromes (somatisation, hypochondriasis).

Answer 74

Possible mechanisms (unclear): Peripheral: increased gut motility, mucosal inflammation. Central: dysregulation of the sympathetic and/or parasympathetic nervous system.

Answer 75

-The brain activations in anterior cingulate cortex were stronger in this and the rest of patients compared to the controls. But unclear if this is due to peripheral or central factors.

Answer 76

Painful sensations in oral cavity (hard palate, tongue, lips and other parts of the mouth). Pain is associated with disturbances of taste, and with sensations of dryness in the mouth (normal secretion of saliva, though). Pain is less frequent in morning hours, increases through the day. Emotions/stress and fatigue increases burning painful sensations. Mental work and cold stimuli decrease pain. Prevalence: larger in females than in males. Etiology: unknown – interactions of central and peripheral mechanisms?

Answer 77

- therapeutic decisions - progress of therapy - evaluation of effects of different treatments - individualised pain therapy (phenotype of patients) - insurance, compensation, legal issues - identifying the presence of pain in vulnerable people (e.g people with communication disorders)

Answer 78

- brain thresholds - self-reports (e.g McGill Pain Questionnaire) - behavioural measures (pain behaviour, facial expressions) - brain and autonomic changes

Answer 79

Minimum amount of stimulation that reliably evokes a report of pain

Answer 80

Time that a continuous stimulus is endured, or the maximum tolerated intensity

Answer 81

- Method of limits: series of ascending and descending stimuli - start from a low level and ascend until the stimulus turns into a pain - Marstock's modification - adaptation for testing thermal pain - Most common method - Method of adjustment: allows participant to tune the stimulus intensity to painful level - Method of constant stimuli: stimuli of fixed intensity are presented in random order (gets rid of expectancy effects)

Answer 82

- Cold pressor test - endures cold pain -Tourniquet ischaemia - ischaemic blood - can use blood pressure cuff

Answer 83

- Can test: warm, cold, heat pain, cold pain (electrical thermode needed) and vibration threshold - training needed to deliver + diagnostic value + phenotyping patients based on their QST profiles - does not measure spontaneous background pain

Answer 84

+ simple to administer + pain expressed in physical units - not suitable for clinical pain - depends on reaction time - response bias: "stoic" style of responding

Answer 85

- categorical scale (no-yes, (no,mild,strong) - verbal scales - numerical scales - visual analogue scales - combined verbal-numeric instruments

Answer 86

- ordinal scale: a number is assigned to pain - simple to use, suits well for rapidly changing pain, sensitive to pain intensity - but boundaries between categories are not known and are only assumed to be equal - tendency towards stereotyped response (e.g getting fed up and always answering with 10)

Answer 87

- ratio scales - pain is represented as continuum that is matched with another modality - subjects are given a reference continuum (intensity of sound, line, length of line etc.) - position of reported pain is proportional to pain continuum

Answer 88

+ true ratio-based scale + easy to administer and score + sensitive to variations of pain due to therapy interventions - unidimensional - sometimes low reliability - some patients do not understand the scale - subject to bias (tendency to use full range of scale)

Answer 89

- Melzack - 78 pain words organised into 20 categories - present pain intensity - location of pain MEASURES - PRI = pain rating index (rank values of the words) -Sensory dimension: categories 1-10 - Affective dimension: categories 11-15 - Evaluative: category 16 - Miscellaneous : categories 17-20 - the number of words chosen - present pain intensity (0-5)

Answer 90

Reliability MCQ confirmed to be reliable (test-retest, split-half reliability) sensory categories: >0.7, affective, ~0.6, evaluative, total ~0.85 (Kilminster and Mould, Int. J. Pharm. Med., 2002) Construct validity factor analysis studies confirmed multidimensionality of MPQ Donaldson (Pain, 62: 101-109,1995) … 3 factors Reading et al. (1979) .. 4 factors Holroyd et al. (1992) … 4 factors Crockett et al. (1977) .. 5 factors Turk et al. (1985) ……. 3 classical factors

Answer 91

15 representative words (11 from sensory and 4 from affective categories) Takes less than a minute to fill

Answer 92

Pain manifests in behavioural changes (acquiring help, giving a sign of warning) Pain behavior: any behaviour informing that pain is being experienced (Fordyce, 1976) Behavioural analysis: helps to pinpoint the pain problem enables to set the baseline level of behaviour against which the effects of treatment will be compared predicts the patient’s response to therapy

Answer 93

Facial expressions verbal pain statements reduced social interactions use of support (cane or walker) guarding = cradling, interrupted movements rubbing avoiding the use of a limb where otherwise appropriate bracing = pain avoidant, stiff posturing

Answer 94

Continuous observation of the whole behaviour in a variety of situations + complexity and stream of behavior - time consuming and expensive - complicated data analysis (scoring) Duration measure: time spent demonstrating behaviour Frequency counts: number of instances of each target behaviour Good inter-observer reliability, bad test-retest reliability

Answer 95

+ useful to pinpoint important features of pain + can be realised in natural settings + unbiased - time consuming - need observer training - ethics - complement rather than replace the self-report instruments

Answer 96

- 1872 - facial pain expressions: patterns of facial activity modified by social and family influences - less dependent on subjects willingness to admit pain - not confound by labels or abstract concepts

Answer 97

Brow lowering Narrowing of the eye orbit Raising the cheek Eyes closed or blinking Raising the upper lip Parting the lips or dropping the jaw

Answer 98

Facial Action Coding System (Ekman and Friesen, 1978) is used to measure Action Units (small movements of facial structures) in an objective manner. New methods (e.g., Machine learning) utilize FACS to evaluate pain or emotional representations in facial expressions.

Answer 99

Which conditions represent risk of unreported pain suffering: Immaturity: Infants, toddlers, preschool children (Lecture 8). Disability: Down’s syndrome, Alzheimer disease (Lecture 8), cerebral palsy, multiple sclerosis. Temporary or permanent restriction of consciousness: general anesthesia, intoxication, sedatives, disturbances of consciousness 4. Inability to communicate: language deficits, mutism, ASD Cerebral palsy is a serious problem associated with pain. CP occurs in about 0.2% of population. CP results from pre/peri/post-natal trauma leading to damage of motor brain regions. It manifests in strong muscle contractures that may cause severe pain. The symptoms may progressively worsen over life time. CP is associated with serious cognitive impairment in 30% of cases. Such patients cannot report their pain, although behavioural signs clearly reveal the presence of pain.

Answer 100

Unresponsive wakeful state. A state of partial arousal without self awareness (eyes track moving objects, swallowing, smiling, grunting, moaning in absence of external stimuli) Can be classified according to duration, Persistent/Permanent Common causes: traumatic brain injury, neurodegenerative disorder, and congenital abnormities of the brain

Answer 101

- Schnacker et al., Pain, 2010 - brief evaluation (1-2 mins) of patient's behaviour at rest or during nociceptive stimulation

Answer 102

- Risk of under-assessment and under-treatment - death due to intestinal obstruction 34x more frequent in people with intellectual disabilities (Roy and Simons, 1987) - people with cognitive deficits receive less medication (Kaasalainen, 1998) - Risk of overtreatment if the level of pain is overestimated - Untreated pain in people who are unable to communicate pain may worsen their cognitive abilities and executive functions

Answer 103

About 35% of people with cognitive deficits cannot understand the question during taking self-reports of their pain Simplified scales, adapted from those assigned for children can help in acquiring self-reports persons with communication disorders

Answer 104

Focusing on units of pain behaviour using validated observational scales: PACSLAC, DOLOPLUS: specialised observation scales to assess pain in patients with dementia (on CANVAS > Lecture week 3 > Supplementary materials) CHEOPS : Children’s Hospital of Eastern Ontario Pain Scale (McGrath et al., Adv. Pain Res. Ther., vol. 9, pp 395-402, 1985) DEPS: Dalhousie Everyday Pain Scale (Fearon et al., Pain, 68: 55-62, 1996) is a short instrument enabling to collect reports of caregivers about intensity of distress, anger, protective behaviour (holding, favouring), and social response. FACS: (e.g. LaChapelle et al., Clin. J. Pain, 15: 13-23, 1999)

Answer 105

Facilitate self-reports in those patients who can respond non-verbally (nodding, eye blinks) Identify sources of pain which in other people would cause pain (leads, tubes, monitoring devices), and check if a patient had a pre-existing pain condition (e.g., osteoarthritis) Consult any symptoms of pain and changes in mood with a family members, caregivers, and other health care professionals Observe indicators of pain (facial, mood, movements, behavioural scales useful) If clear signs of pain present, initiate an analgesic trial (e.g., analgesic drugs If the analgesic trial confirmed pain being present, a collaborative pain treatment plan should be designed

Answer 106

Canadian Institute of Health Research (2022): Sex is often associated with biological factors, such as genetics, sex hormones, and physiology, and usually involves comparisons between men and women. Conversely, gender is associated with psychological and sociocultural factors, such as beliefs, expectations, and stereotypes, and how men and women behave and interact with one another. Binary categories are commonly used (e.g., male/female, man/woman, and boy/girl), although gender is not constrained to this and encompasses broader aspects”

Answer 107

Chesterton et al. (Pain, 101: 259-266, 2003) analysed differences in pressure pain threshold (pressure on the interossei muscles - back of hand). Men required greater levels of mechanical pressure to elicit pain response Pain threshold differences were stable over one hour period

Answer 108

Pain thresholds lower, pain endurance shorter in females than males. Riley et al. (Pain,74:181-187, 1998) Meta-analysis of 21 studies analysing differences between females and males in experimental pain threshold and pain tolerance. Largest differences in pain thresholds and pain tolerance for electrical and pressure stimulation: males showed higher thresholds than females. The mean effect size over different types of stimuli was 0.55 and 0.57 for pain threshold and pain tolerance, respectively. Authors calculated sample sizes required for these size effects; the groups should count at least 41 subjects each. Thus, early studies that have not reported statistically significant differences might suffer from low power. N.B.: Greenspan and Taub (2013) performed a similar calculation including newer studies and raised the recommended cohort sizes to 49

Answer 109

Racine et al. (2012 Part 1) analysed 172 papers on sex differences in experimental pain over a 10 year period with a systematic literature review: Pain threshold, pain tolerance, pain intensity: no consistent differences in pain intensity (debateable) or pain thresholds in various pain modalities pain tolerance was greater in males than females for cold (in 81% of studies), heat (80%), and pressure pain (86%) low statistical power in many studies

Answer 110

Re-analysis of 122 studies originally reviewed by Racine et al. (2012). The number of studies showing increased pain threshold and pain tolerance in males compared to females is much larger than for a reverse direction.

Answer 111

Data on pain sensitivity were derived from the large scale OPPERA study (+4000 ppts) which considered males and females. Among the most sensitive 10%, 83% are women. A 4.8 times greater proportion of females than males among 10% of pain most sensitive people

Answer 112

A painful conditioning stimulus (e.g., water of 1˚C) in one loci will attenuate the pain associated with the test stimulus in another location. A non-painful conditioning stimulus (e.g., water of 30˚C) will not attenuate the pain associated with the test stimulus on opposite hand The drop in pain ratings to the test stimulus under a painful and non-painful conditioning stimulus is the measure of conditioned pain modulation Conditioned pain modulation activates the endogenous opioid system and inhibitory synapses in spinal cord dorsal horn neurons Popescu et al. (2010) reviewed 17 studies comparing effects of pain modulation in males and females males showed stronger inhibitory control of pain intensity in most studies less clear differences in pain threshold and spinal reflexes Males activate m-opioid receptors during pain more strongly than females n

Answer 113

Increased levels of Oestrogen in females is associated with increased pain threshold Meta- analyses indicate no convincing data on differences in pain sensitivity in females taking or not taking oral contraceptives (Racine et al., 2012/2; Greenspan and Taub, 2013) Hormonal replacement therapy (HRT) in menopausal period: smaller experimental pain in females receiving HRT than those not receiving (Racine et al., 2012/P2)

Answer 114

Meta-analysis of 19 pain studies (Riley et al., Pain, 81: 225-235,1999): Pain thresholds for pressure, and cold pain were greater in follicular than in luteal phase. Pain type specific? Painful electrical stimulation yielded contradictory results. None of 12 studies performed since 1998 has reported any effect of MC on pain intensity or pain thresholds (Racine et al., 2012/2) MC effects on conditioned pain modulation (Rezaii et al., J. Pain, 2012) suggest greater pain inhibition during ovulation period Pressure pulses (test stimuli) to masseter muscle during concurrent cold pressor (5 min, conditioned stimulus) pain in contralateral arm in 3 periods of MC (early follicular, ovulatory, mid-luteal) No effects of MC on cold pressor test – MC appears to modulate only the inhibitory mechanism

Answer 115

Straube et al. (HBM, 2009) applied painful electrical stimuli to the dorsum of the hand in males and females. Females had greater activation in the medial pre-frontal cortex – shown below pain threshold and related to pain anticipation, Males showed more activation in anterior insula. Greenspan and Taub (2013) summarised results of 11 brain imaging studies in experimental pain Variable patterns of activations across studies, with perphaps only insula consistently yielding greater activation during painful stimulation in males than females A methodological problem: stimulus intensity was matched to be subjectively identical in males and females but only in some of the studies

Answer 116

Females compared to males: 1. have greater prevalence of chronic pain syndromes. 2. experience more intense pain for comparable pathology (e.g. injury, surgery). 3. show stronger analgesia after administration of opioids Fillingim et al. (2009) There are types of pain which do not show sex differences, e.g., cancer pain

Answer 117

More female patients exceeded the criterion for Pain and delayed recovery P < .001. Phillips et al., (2003) Gender and anxiety levels influences postoperative pain: (2020) Liang Xu & Xia

Answer 118

Tighe et al. (2014) analysed sex differences in post-operative by collecting numerical rating scales (0-10) in 330,000 patients in Florida over one year. Serious surgeries: amputations, cardio-thoracic, orthopedic. Measures: severe pain events mean pain etc.. From day 1 to 5 post-operatively. In all pain measures, females had larger scores than males e.g., day 5 : statistically significant difference with a mean score of 4.1 (99% CI 4.1–4.1) for females and 3.74 (99% CI 3.7–3.8) for males

Answer 119

Chia et al. (Can. J. Anesth. 49: 249-255, 2002) analysed the consumption of morphine in the regime of patient-controlled analgesia. 2298 patients undergoing abdominal, chest or limb surgery. Consumption of opioids was screened from 12 to 72 hours post-operation. Males take higher dose BUT… Campesi et al. (2012): Females require less opioids than males to reach comparable level of analgesia

Answer 120

Morphine induces greater opioid analgesia in females than males in experimental pain Patient-controlled analgesia shows reduced morphine doses in females than males The longer the analgesic intervention, the larger the differences between males and females.

Answer 121

Serrdarevic (2017) evaluated gender studies of opioid use (8 total) and data from +8000 people in a health engagement program in USA. Half reported use of prescription opioids USA gender prevalence review of studies: Women are more likely to use prescription opioids compared to men. Health data outcome: females significantly higher usage of opioids in past and present.

Answer 122

Keogh et al. (Pain, 2005) reported inferior outcomes for females, relative to males, following interdisciplinary chronic pain management programs. This was replicated in analysis of PMP treatment for veterans in the USA (shown is pain related fear but result was also similar for pain outcomes). Murphy et al., 2016 JRRD.

Answer 123

Wise et al. (Pain, 96:335-342, 2002) analysed pain thresholds and pain tolerance thresholds in males and females. They used the Gender Role Expectations of Pain questionnaire (GREP) to measure gender-specific expectations about pain (willingness to endure and communicate pain). GREP was a significant, although not exclusive, predictor of pain tolerance and pain threshold in cold pressor test. Pool et al. (Pain, 2007) administered questionnaires to measure how males and females identified themselves with “ideal men” or “ideal women” roles. Greater experimental pain tolerance in men identifying with traditional male roles, compared with women identifying with traditional female roles

Answer 124

Stereotypes can be damaging, e.g., men are considered less expressive and more likely to engage in avoidance when in pain, whereas women are perceived to be more likely to catastrophize and cry (Keogh, 2022). Hirsh et al., (2208): when viewing virtual patients, observers rated women as having more pain and being worse at coping. Schafer et al., (2016) found that female patients were viewed more negatively in clinical scenarios (lower table) relative to males.

Answer 125

Females might have an additional antinociceptive circuit that is being implemented during childbirth, and this pattern might interfere with the default pain processing mode leading to greater pain. Males have been exposed more frequently to injuries, and natural selection contributed to affirmation of less sensitive pain genes.

Psychobiology Of Pain (Year 3) Flashcards

(152 cards)