Pain Flashcards
What is allodynia?
pain due to stimulus that does not normally provoke pain
What is analgesia?
absence of pain in response to stimulus which would normally be painful
What is hyperalgesia?
Inc pain from stimulus that normally provokes pain
What is hypoalgesia?
Diminished pain in response to normally painful stimulus
What is neuropathic pain?
Pain caused by lesion or disease of somatosensory NS
What is neuropathy?
Disturbance of function or pathological change in a nerve
What is nociceptor?
High threshold sensory receptor of peripheral somatosensory NS capable transducing and encoding noxious stimuli
What is nociceptive pain?
pain that arises from actual or threatened damage to non-neuronal tissue and is due to activation of nociceptors
What is a pain threshold?
minimum intensity of a stimulus that is perceived as painful
What is pain tolerance level?
Max intensity of a pain-producing stimulus that a subject is willing to accept in a given situation
What is paresthesia?
Abnormal sensation, whether spontaneous or evoked
What are the three elements/pathways of pain?
nociception (detection) = peripheral
Transmission = spinal
Perception (interpretation) = brain
What pain is detected by alpha-delta fibres?
Nociceptive pain
High intensity mechanical or heat stimuli
Sharp, transient, pricking pain
What pain is detected by C-fibres?
Nociceptive pain
Intense thermal, chemical and mechanical stimuli
Delayed, prolonged aching and burning pain
What amino acids are responsible for fast nociceptive pain transmission?
Glutamate
Aspartate
What neuropeptides produce a slow, prolonged effect?
Substance P
Calcitonin-gene release peptide (CRGP)
What neurotransmitters/AA causes acute pain stimulus?
Release of glutamate or aspartate
What neurotransmitters/AA causes maintained/intense stimulus?
(hypersensitivity)
Neuropeptides as well as glutamate
Inc NMDA receptor sensitivity
What causes nociceptive pain?
burns
fractures
appendicitis
myocardial pain
What causes neuropathic pain?
Peripheral (compression or damage)
- herpetic neuralgia
- trigeminal neuralgia
- diabetic neuropathy
Central
- pathophysiological changes in brain or spinal cord
- nerve plexus avolution
- phantom limb pain, thalamic pain (post stroke)
Outline the treatment of neuropathic pain
50% reduction in pain = appropriate positive clinically relevant end point
Simple analgesia = paracetamol
Adjuvant therapies = TCAs, SNRI, antiepileptics
- amitryptyline, gabapentin, pregabalin, duloxetine
What is breakthrough pain?
Pain that occurs between doses of regular pain relief
Intermittent, transitory pain that occurs over the top of chronic pain
May have temporal, precipitating or predictable patterns
How is breakthrough pain treated?
Give extra (breakthrough) dose of regular analgesic
What is incidental pain?
Occurs on or is exacerbated by activity (doing something + feeling the pain)
Common post surgery or in patients with metastatic bone pain
