Intro to Persistent Pain Flashcards
How many people in the world experience chronic pain
1/4 of people in the world
Why is the pain epidemic happening?
- Industrial Revolution
◦ Machinery started doing the work for us, so we became more sedentary
◦ Amount of back pain is staying the same but disability is increasing
Purposes of pain
- protection/survival
- create vigilance
- shift salience
*** ultimately the goal is to create some sort of behavior response to minimize damage/threat and enhance survival
does structural pathology paradigm work for chronic pain?
nope
only acute
mature organism model
- brain: “central scrutinizing center”
- sample from the tissues as well as the environment
- information is integrated to create response for the best advantage
what is pain produced by?
THE BRAIN
nociception
- The process by which information about actual or potential tissue damage is relayed to the brain
- thermal, chemical, mechanical
does nociception always equal pain?
no
does damage always equal pain?
no
Normal tissue healing
- tissues will undergo relatively predictable stages of healing over time
- pain experience is poorly correlated to those stages of healing
- many people suffer from significant pain, yet no injury or disease process can be identified
pain lasting more than a couple of months has a greater potential to be…
a pain problem
neuroplasticity
- nervous systems ability to change structure and function
- normal ongoing state throughout the lifecycle
adaptive neuroplasticity
purposeful, protective
maladaptive neuroplasticity
CNS is protecting us from things not threatening and damaging
structural changes in learning
- increased gray matter volume and density in task-specific areasf
functional changes in learning
- reorganization/increased activity
- motor
-sensory - cognitive
- emotional
expectations drive…
outcomes
what drives expectations
beliefs
who has the strongest influence on attitudes and beliefs
healthcare providers
PTs with high fear avoidance and higher biomedical orientation….
- Delay return to work
- Delay return to activity
- Tendency to not limit number of sessions
- CLBP approached from a strong biomedical model without addressing psychosocial factors
- Lack of confidence in biopsychosocial model
- Dislike treatment complicated cases
- Feel psychosocial assessment is not their role
PTs tend to….
- Assess their perception of patient’s willingness to engage in self management
- Engage more actively with patients whom we perceive to be more engaged
words that harm
- Showing pictures/models –> explain what is happening but also explain that tissues heal
- Misunderstood medical terms/diagnoses
- Literacy skills – strong predictor of health
- Internet usage by patients seeking answers
words to avoid/alternatives
- chronic degenerative changes –> normal age changes
- instability –> needs more strength/control
- bone on bone –> narrowing
- paresthesia/hyeresthesia –> altered sensation
- disease –> condition
optimism
- Protects against anxiety
- Associated with reduced pain intensity and physical
symptoms related to open heart surgery - Significant predictor of positive health outcomes
convey to patients:
- Inflammation is normal
- Immune responses are normal
- Sensitivity as normal and learning
- Normal healing
therapeutic alliance
relationship between the patient and the provider
descending inhibition of pain from higher cortical centers
- anterior cingulate cortex: escape/avoidance behaviors
- insular cortex
- pre-frontal cortex
- amygdala
** send input directly to the PAG/RVM
descending inhibition of pain - PAG-RVM pathway
- electical stimulation –> inhibits spinal neurons that respond to noxious stimuli
- analgesia in rats, cats, and humans
- Efferent projections from RVM to SC are involved in inhibition of nociception
Descending inhibition of pain - neurons in the RVM
- On cells: facilitation/sensitization
- Off cels: inhibition
- neutral cells can alter their phenotype after tissue injury; can develop on-like or off-like activity after inflammation
neurotransmitters - opioids/morphine (RVM)
- excites off cells
- suppresses on cells
neurotransmitters - norepinephrine
- dorsolateral pontine tegmenjtum is primary source of NE in spinal cord
- decreases activity of spinal nerves
- causes anticociception
- reduces hyperalgesia
descending inhibition of pain - somatosensory Cortex
- sends fibers to spinal cord directly via CST and indirectly via PAG
- inhibits neurons in STT
- presynaptic inhibition of 1st order afferents
descending inhibition of pain - motor cortex
stimulation may reduce pain in patients with neuropathic pain
descending inhibition of pain - descending noxious inhibitory controls (DNIC)
- reduces hyperalgesia/ pain
- reduces DH neuronal activity
-mechanism not well understood - decreased efficiency of this pathway in patients with chronic pain
other areas in the brain that inhibit pain/nociception when activated
- Hypothalamus
- Thalamus
- Somatosensory cortex
Relay directly or indirectly through - Prefrontal cortex
the RVM - Amygdala
- Reticulospinal Tract
- all relay directly or indirectly through RVM
systems affected by placebo
- pain
- motor performance
- autonomic and CV
- endocrine
- immune
