Lecture 5 PT 2 Flashcards
What is central sensitization
Central neurons respond disproportionately to continuing nociceptive input
Cellular changes due to central sensitization
__________ spontaneous activity
Excessive response to _______ stimuli
_________ after discharge periods following stoppage of stimuli
Receptive fields of central neurons are ______ than normal
[Excessive] spontaneous activity
Excessive response to [afferent] stimuli
[Lengthened] after discharge periods following stoppage of stimuli
Receptive fields of central neurons are [larger] than normal
When both central sensitization and peripheral inputs cause neuropathic pain the treatment must…
Target both areas
Antinocieption vs pronociception
Antinociception - Inhibition from top down
Pronocicepton- heightening of stimulus
Parasthesia vs neuropathic pain
Parasthesia- Abnormal painless sensation (typically tingling)
Neuropathic pain - Pain arising as a direct result of nerve lesion/disease
Central sensitization is characterized by ________
Dysesthesias - Unpleasant abnormal sensation that can occur on its own or with stimulation
Allodynia
Pain caused by something that wouldn’t normally cause pain
Note: cross-talk is hypothesized between light touch receptors and Nocioceptors
Hyperalgesia
Primary vs secondary
Primary- stimuli that are mildly painful cause excessive sensitivity
Secondary- Pain spreads to uninjured areas close to injury site
Spontaneous pain
Pain unrelated to external stimulus
Temporal summation
Increased pain due to repeated stimulus or continued presence of stimulus
Note: “wind up occurs due to heightened output at 2nd level neurons within dorsal horn
True or false: fibromyalgia is a psychiatric disorder
False
Fibromyalgia is what?
widespread pain, abnormal pain processing, or pain without external stimulus
Fibromyalgia patients have significantly less graymatter in medial frontal cortex, mid/posterior cingulate cortex, and insular cortex (Note: these are pain inhibiting areas)
Additionally their stress response areas of brain are shown to amplify pain signals
Headache redflags: signs of excessive pressure:
Headache upon waking up
Headache with coughing
Worse when laying down
Vomiting
Headache redflags: signs of serious intracranial disease
Progressive worsening
Neck stiffness
Rash/fever
History of CA and HIV
Causalgia/ reflexive sympathetic dystrophy are older names for what?
Complex regional pain syndrome
Complex regional pain syndrome
Complex regional pain is characterized by pain that is greater than would be expected from the injury that causes it.
-Triggered by abnormal response to trauma and disuse of limb
- Pain and vascular changes/atrophy not related to nerve damage
-Time between trauma and onset highly variable
Chronic nonspecific LBP
__% have no specific injury
__% resolve in 6-12 weeks
90%
70%
True or false: Complex regional pain syndrome is a psychological diagnosis
False
Ectopic Foci
Regions outside of nociceptors that are damaged and generate action potentials that stimulate the nociceptors
Demylinated regions are more likely to have this
this causes neuropathic pain
Ephaptic transmission
AKA cross-talk
Demyelination causes action potential from 1 neuron to spread to another
Example: light touch receptor neuron activates nociceptors neuron
-Thought to be the cause for Allodynia
The most common site of neuropathic pain is in the _________
Periphery
How does the nervous system reorganize due to neuropathic pain?
Synapses form between A-beta fibers and 2nd order neurons replace C fibers so that the A-beta neurons now carry nociceptive signals
-Dorsal horn overly active
-Cerebral cortex shows signs of reorganization
In people with a spinal cord injury, 66%, and post-stroke (12%) experience neuropathic pain from the _______ without external stimulation
Thalamus
A smaller percentage of people with phantom limb sensation have _________
Phantom limb pain
The amount of phantom limb pain is correlated to the amount of….
Cerebral cortex reorganization
What are the 3 D’s of chronic pain that a therapist must address
Distress
Disuse
Disability
