Pathophysiology of Pain Flashcards
What pain theory was characterized by phantom pain patients? What is the hallmark of this theory?
Neuromatrix Theory - people become hard-wired to feel pain that is no longer present
What are the three types of pain?
Nociceptive, neuropathic, nocioplastic
What is analgesia?
Absence of pain from a stimulus that would normally be painful
Pain is carried by what types of fibers?
Small, slow fibers
What neurotransmitter prolongs the action of glutamate?
Substance P
What symptoms often accompany widespread, nocioplastic pain?
Fatigue, sleep, memory changes, mood changes
This type of pain is associated with numbness and tingling.
Neuropathic/Central pain
What sensory fibers transmit sharp pain?
A-delta fibers
What fibers can prohibit impulses from small, slow fibers?
Large A-beta fibers
This type of pain occurs when nociceptors are activated in response to tissue damage.
Nociceptive pain
What compounds activate and sensitize nociceptors?
Bradykinin, histamine, prostaglandins, K+
How does the specificity theory characterize pain?
As an independent sensation with specific receptors that connect with specific regions of the brain
A patient states they experience pain when the wind blows against their skin outdoors. What term describes this pain?
Allodynia - pain from a non-painful stimulus
True/False. C fiber signals to WDR neurons can be amplified and produce a greater pain sensation.
True. This phenomenon is called windup
Where do the subjective sensation and modulation of pain take place?
Thalamus & somatosensory cortex
What type of pain is mediated by autonomics?
Visceral pain
What term describes extreme sensitivity to pain?
Hyperalgesia
A patient presents with pain after a shopping cart ran into their leg. The leg is red and swollen. What diagnosis may describe the exacerbated physiological response?
Complex Regional Pain Syndrome due to reflex sympathetic dystrophy
What is hyperpathia?
The sensory threshold for pain is higher, but often results in a longer pain sensation once activated
This type of pain arises from direct injury to nerves.
Neuropathic pain
Visceral pain is carried by what autonomic fibers?
Sympathetic fibers
How do paresthesia and dysesthesia differ?
Paresthesia is an abnormal alteration of pain sensation. Dysesthesia in an abnormal, unpleasant sensation that is not painful
What neurotransmitters are associated with pain?
Glutamate, norepinephrine, substance P
Individuals with chronic pain are at higher risk for depression. Why might this be?
Depletion of serotonin and endorphins
This type of pain may be dull or burning, but is reproducible.
Somatic pain
What pain theory combines the specificity and pattern theories and hypothesizes that pain is carried by specific fibers that can be inhibited or stimulated by other nerve impulses?
Gate Control Theory
What is the action of A-beta fibers on wide dynamic range (WDR) neurons?
Inhibit nociceptive input to WDR neurons from A-delta and C fibers
What sensory fibers are unmyelinated?
C Fibers. A-beta & A-delta fibers are myleinated
What is a common cause of central pain?
Lesion or dysfunction of the pain-sensing system
What information is transmitted via A-beta fibers?
Touch, pressure, vibration, proprioception
How does the pattern theory characterize pain?
Pain shares endings with other sensory modalities, but different patterns of stimulation determine pain vs. non-pain
