Neurophys Of Pain Flashcards
What is nociception
neural and mechanical
Reception of signals in the CNS evoked by activation of specialized sensory receptors called nociceptors that provide information about tissue irritation or damage.
— may or may not lead to the experience of pain (all about the interpretation of the nociceptors)
What is pain
neural, mechanical, and behavioral
Perception of an unpleasant sensory or emotional experience associated with or resembling that associated with, actual or potential tissue damage.
can be highly subjective!!!
What is the updated pain definition from the international association for the study of pain
- Pain is always a personal experience that is influenced to varying degrees by biological, psychological, and social factors.
- Pain and nociception are different phenomena and pain cannot be inferred solely from activity in sensory neurons
- people learn the concept of pain
- pain usually serves an adaptive role, but it may have adverse effects on function and social/psychological well-being.
- verbal description is only ONE of several behaviors to express pain. The inability to communicate does not negate the possibility that a human or nonhuman animal experiences pain
How do people with persistent pain present?
There is an unclear relationship of pain and tissue damage//input
- Difficult to predict flare ups
- Poor tolerance of normal therapeutic approaches
- Problems with physical and functional upgrading
- Difficulty generalizing gains to other activities
What are the central mechanisms of pain
for persistent pain
1. Central sensitization
2. Affective
3. Motor/autonomic
Big picture — what is central sensitization?
- Altered cognition and interpretation of nociceptive signals — their pain alarm is on overdrive!
- Hypersensitivity by changing the sensory response of normal inputs
- Pain is no longer coupled with nociceptive input
- Altered sensory processing. Can’t really use descending inhibition.
What is the difference between temporal summation and long term potentiation?
Temporal summation — things can build up in time. Higher frequency of stimulation.
Long term potentiation — responses are bigger and we get long term potentiation to other neurons = bad learning!
What do person’s with persistent pain demonstrate with brain activity
They show more brain activity in response to painful stimuli and have activity in regions normally not involved in pain sensation
What is the affective pain mechanism
Type and location of symptoms are less important because intensity and disability of MSK pain are determined more by treatable psychological and social factors than by pathophysiological process.
— so pain is more of an emotional response which drives pain scales up
*central pathways are involved
*related to negative emotions and perceptions
What is the affective pain mechanism often associated with?
Life changing events (trauma, abuse)
- anxiety, depression, anger, blame
ability to cope is important variable
What is the motor autonomic pain mechanism
Autonomic (SNS/PSNS) dysfunction
— can often see lymphedema, skin coloration changes, hair loss, excessive sweating, and changes in muscular tone
— also neuroplasticity changes like “brain smudging” and somatotopic representations are disrupted
What are the cutaneous/subcut mechanoreceptors?
- our touch guys
A alpha and beta — large/medium myelinated fibers associated with specialized receptors.
What are thermal receptors?
Our temperature guys
— A delta (myelinated) and C fibers (not myelinated)
What are nociceptors ?
Our pain guys
— A delta and C fibers that have FREE NERVE ENDINGS
What are muscle/skeletal mechanoreceptors?
Our limb/proprioception guys
— A alpha, beta, and delta (all myelinated)
