Pain Flashcards
1
Q
2 Major Pathways
A
- 1- Spinal Visceral Afferents
- Detected by nociceptors (ADEQUATE cold, chemical, mechanical, heat stim) –> DRG –> dorsal horn of SC –> decussate –> up spinal thalamic tract –> thalamus
- 2- Vagal Visceral Afferents
- Visceral sensory fibers –> nucleus tractus solaritus –> multiple other brain centers
2
Q
Spinal Visceral Afferent Path
A
- Detected by nociceptors (ADEQUATE cold, chemical, mechanical, heat stim) –> DRG –> dorsal horn of SC –> decussate –> up spinal thalamic tract –> thalamus
**Can also travel via dorsal column path
- Nociceptors usually unmyelinated C fibers or lightly myelinated a-delta fibers
- Runs w/ SYMP but not part of ANS
- Use coding (inc firing rate when noxious stim) or silent afferents (only fire when noxious stim)
3
Q
Vagal Visceral Afferent Path
A
- Visceral sensory fibers run w/ PARASYMP but are not part of ANS (motor) –> nucleus tractus solaritus –> multiple other brain centers
4
Q
Hyperalgesia v. Allodynia
A
- Hyperalgesia = painful stim is more painful than should be
- Allodynia = when non-painful stim becomes painful (ex - irritable bowel syndrome)
5
Q
Inflammatory Pain
Neuropathic Pain
Central Pain
A
- Inflammatory - due to cytokines (can sensitize primary sensory fibers), WBCs, immune response
- Neuropathic - pain due to injury to nerve itself (common in visceral cancers, trauma, post-operative)
- Central - affect nerves anywhere in path (SC, brain); esp if widespread/appears to arise from multiple organs
6
Q
How to treat inflammatory pain (3)
A
- NSAIDs usually 1st choice (safe yet not as affective)
- acute opioid use
- Tramadol (relatively weak mu-receptor agonist that also acts as SSRI)
7
Q
How to treat neuropathic pain (2)
A
- Opioids not as good in these cases!!
- Ca++ channel blockers (Gabapentin)
- tricyclics
8
Q
How to treat central pain
A
-pharm not as good; cognitive/psych therapies (meditation, CBT, yoga, etc)
