Lecture 20 - Pain and Sleep Flashcards
What is allodynia?
Pain in response to a stimulus that normally does not induce pain, such as a feather touch.
When we experience repeated noxious stimuli, such as heat, our response to that pain becomes stronger with each additional instance.
What happens for those with chronic pain upon receiving repeated instances of noxious stimuli?
Their perception of pain also increases with each repeated instance, but the signal is significantly larger and increases at a faster rate than those without chonric pain.
“Pain inhibits pain”. What does this mean when it comes to how we perceive multiple instances of pain at once?
The concurrent presence of multiple instnaces of pain decreases the perception of each individual pain.
Have studies found that there is a strong correlation between number of hours people sleep and symptoms of pain the following day?
Yes.
In a study that looked at different types of sleep disruption on pain tolerance, what was found?
Total sleep deprivation lead to the biggest decrease in pain tolerance.
Partial sleep loss/restricted sleep resulted in the next largest decrease in pain tolerance.
Sleep fragmentation resulted in a decrease in pain tolerance, but to a lesser extent than the other forms of sleep disruption.
What does Conditioned Pain Modulation (CPM) refer to?
The decrease in one perception of pain due to the presence of another pain.
This is thought to come about by the release of endogenous opioids in the PAG.
It has been found that when sleep pressure builds up perceived pain intensity increases.
However, what describes that variance in pain intensity to a much greater extent than sleep pressure (process S)?
Circadian rhythms (process C).
Circadian rhythms appear to play a key role in how we perceive pain intensity.
Does sleep deprivation lead to increased levels of inflammation?
Yes.
This is one of the ways sleep is related to pain.
What are some ways lack of sleep worsens or perpetuates chronic pain?
Inflammation.
Mood.
Decreased levels of chemicals, such as dopamine.
In a study that looked at the role of sleep and pain they had participants go into an fMRI after a good night of sleep and receive a heat pain stimuli. They then had them do the same thing after a night of no sleep.
What did they find?
They found that the pain threshold was higher (lower pain sensitivity) after a good night of sleep and lower (higher pain sensitivity) after no sleep.
They also found increased activation in regions associated with the ascending path, such as the somatosensory cortex, and decreased activation in areas associated with the descending path.
In a study that looked at the effect of sleep medication on pain reduction in those with chronic pain, what did they find?
They found that sleep medication improved pain symptoms in those with chronic pain, suggesting that sleep plays a key role in chronic pain and pain in general.
Has it been found that treating patients with comorbid insomnia and chronic pain CBT for insomnia leads to a decrease in pain symptomms?
yes.
What area and process are known to be involved in the relationship between sleep and pain?
The nucleus accumbans.
The reward system, such as dopamine.
