Physiological Effects Of Manual Therapy

Question 1

What components are part of the corticolimbic system?

Answer 1

• amygdala => fear + anxiety emotions (nuclei)
• hippocampus => memory + reward/motivation
• hypothalamus => maintains homeostasis

Question 2

What happens in the theoretical model of pain onset?

Answer 2

• mechanical irritation/inflammation starts => below corticolimbic pain threshold
• over time mechanical/inflammation continues => above corticolimbic lowered pain threshold
• get a ‘sudden’ acute onset of pain => hyperalgesia => pain goes above ‘robust’ pain threshold
• however, could be building over time, prior to threshold is ‘under the radar’’
• nociceptive is over the corticolimbic threshold
• corticolimbic = limbic + amygdala => descending and only stimulated when threshold is crossed
• thresholds aren’t fixed; based on past history and experience

Question 3

What is the aim of manual therapy when treating a patient in pain?

Answer 3

• to raise the lowered pain threshold to a ‘robust’ pain threshold

Question 4

What are the goals of pharmacological pain treatment?

Answer 4

• increase inhibitory neurotransmitter => analgesia => removing response between Nociception + pain
• prevent peripheral + central sensitisation
• restore normal responsiveness of Nociception

Question 5

How is pain modulated in the amygdala?

Answer 5

• thoughts
• beliefs
• expectations

Question 6

Which drugs affect the midbrain/PAG?

Answer 6

• opioids
• NSAIDs

Question 7

Which drugs affect the medulla?

Answer 7

• opioids
• cannabinoids

Question 8

Which drugs affect the dorsal horn?

Answer 8

• tricyclic anti-depressants (TCAs)
• selective serotonin/noradrenaline reuptake inhibitors (SSRIs or SNRIs)
• alpha-2 agonists
• opioids

Question 9

What are the side effects of common pain killers?

Answer 9

• paracetamol = liver damage
• NSAIDS = gastritis, ulcers, kidney failure, stroke
• codeine - constipation
• morphine - addiction, severe constipation, teeth fall out
• amitriptyline - dry mouth => suicidal tendencies
• gabapentin - dizziness, somnolence (drowsiness), peripheral oedema
• NMDA - receptor antagonists e.g. katamin
• cannabinoids
• capsaicin patches

Question 10

What are the effects of STM?

Answer 10

• depth of technique will cause different neurophysiological response
• activation of a-beta fibres => pain-gating where c-fibre input is abolished
• deeper techniques => mildly noxious => conditioned pain modulation => activating descending PAG-RVM pathway
• painful stimulation => DNIC (diffuse noxious inhibitory control)

Question 11

What happens during joint articulation?

Answer 11

• stretching joints -> intra-articular pressure + lengthen capsules + ligaments => reduced afferent barrage (input signal reduced)
• increases pressure-pain thresholds (PPT) locally + widespread
• no effect on thermal pain thresholds (TPT)

Question 12

What effect does spinal manipulation have on pain?

Answer 12

• changes secondary hyperalgesia + allodynia
• changes pressure pain threshold
• changes suprathreshold heat response
• changes temporal summation threshold (signal sent to axon hillock doesn’t reach threshold to send afferent signal to brain)
• perceived pain intensity
• perceived pain threshold on ipsilateral + contralateral side increase following SMT
• remote + local changes

Question 13

What are the effects of manual therapy on the autonomic NS?

Answer 13

• HVT + articulation => increase HR + skin conductance + decrease in salivary amylase (increased sympathetic activity)
• balance ligamentus techniques, crank-sacral => altered parasympathetic activity
• SMT => increase in sympathetic + decrease in parasympathetic activity

Question 14

What is the role of light touch (c-fibres) in pain reduction?

Answer 14

• stroking, warmth + light pressure => oxytocin + opioid release (pag+rvm)
• promotes relaxation + well-being
• c-tactile afferents on non-hairy skin => project to insular cortex
• forms an affective homunculus in insular cortex => map of pleasure

Question 15

What are the peripheral tissue drivers of pain in the nervous system (neural axis)?

Answer 15

• pro-inflammatory chemicals from tissue damage or neurogenic inflammation
• active immune response + chemical accumulation
• build up of metabolic waste
• inappropriate mechanical response from tissues
• direct irritation of a nerve

Question 16

What are the peripheral tissue drivers of pain in the spinal cord (neural axis)?

Answer 16

• spinal cord c-fibre nociceptive input (neurogenic inflammation => knock on effect)
• reduced disinhibition
• abnormal activity in inter-neurone => referred pain
• physiological + pathological lowering of depolarisation of potentials

Question 17

What are the peripheral tissue drivers of pain in the brain stem (neural axis)?

Answer 17

• altered biological patterns e.g. sleep, breathing, hormone release
• heightened state of arousal + stress
• dismissed pleasure from altruistic acts, feeding etc.

Question 18

What are the peripheral tissue drivers of pain in the limbic system (neural axis)?

Answer 18

• depression + psycho-emotional states
• anxiety + fear
• inappropriate retained memory of trauma

Question 19

What are the peripheral tissue drivers of pain in the neo-cortex brain platform (neural axis)?

Answer 19

• belief constructs e.g. hurt = harm
• no context of pain experience
• explaination of pain reduces sense of understanding/control
• reduced inhibition + loss of discreetness in somatosensory cortex (smudging)
• inappropriate motor programs
• excessive prediction of pain

Question 20

What mechanisms of pain relief are available at the distal neuroaxis

Answer 20

• reduce local tissue afferent input
• increase safe afferent (non-noxious) input
• gate control
• increase descending inhibition (DNICs + endogenous analgesia)
• increase c-fibre afferent input to insular (light touch)

Question 21

What mechanisms of pain relief are available at the proximal neuroaxis?

Answer 21

• distraction
• habituation
• removal of painful movement memories
• learn pain-free movement memories
• pain education/cognitive therapies
• graded exposure to mechanical stimuli
• set expectations

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Question 22

What central mediators can impact pain experience?

Answer 22

• changes in spinal excitability + motor function
• decrease in cortical excitability + activation in brain pain processing areas
• decreased activation of facilitatory in inhibitory pathways
• changes in resting state bran functional connectivity

Question 23

What peripheral mediators can impact pain experience?

Answer 23

• Biomechanical e.g. increase ROM + decrease passive stiffness + active stiffness
• neurophysiological e.g. change concentration of inflammatory + pain mediator substances

Question 24

How can a patient be treated ‘bottom-up’ for pain?

Answer 24

• manual therapy

Question 25

What are ‘top down’ moderators of pain?

Answer 25

• habituation
• graded exposure to mechanical stimuli
• sensory discriminions training
• cognitions
• expectations
• placebo/meaning response
• contextual factors
• therapist effect

Question 26

What is the effect of attention + distraction on pain?

Answer 26

• distraction + hypnotic => attenuation of pain
• anticipation + focus => exacerbation of pain

Question 27

What is habituation?

Answer 27

• a type of synaptic learning => decreased behavioural responses to repeated stimulation
• decreased neurotransmitter => progressive decrease in size of postsynaptic potential
• MT sensory input => completes with pain => restore sensitive nervous system
• reorganisation of cortical map
• non-threatening stimuli should habituate; otherwise they are a threat + sensitise

Question 28

How