somatic referred pain

• • Not all referred pain is neuropathic or nerve related
  • while radicular/neuropathic pain is usually referred, not all referred pain is radicular/neuropathic
• Somatic referred pain - convergence mechanisms pt1:

  • central sensitisation can lead to an expansion of the receptive field of dorsal horn neurones
  • so as neurones get sensitised, where we feel pain could spread too
  • referred pain can arise from just nociceptive afferent input in the absences of any nerve injury - somatic referred pain
• Somatic referred pain - convergence mechanisms pt2:

  • area of pain and afferents (sensory) neurones nearby could converge to a common dorsal horn cell - if the dorsal HC is receiving input from the area of pain, it can express that pain through the sensory neurones its connected to around the body - can happen via:
  • sensory neurones converge via a common nerve
  • sensory neurones emerge via separate neural pathways but converge on the same centre in the CNS
  • so convergence is one mechanism for referred pain
• Lumbar somatic referral patterns:

  • lumbar somatic referral tends to go to the buttocks and the posterior thigh region
  • but cant differentiate whether the pain was from an L3, L4, L5 or S1 problem
  • referral below the knee is possible but is less common with lumbar somatic referred pain
• Thoracic somatic referral patterns:

  • minimal research into thoracic pain
  • thoracic spine is implicated with upper limb, pain radiating around thoracic cage and thorax symptoms
  • unilateral chest pain is possible
  • potential for referral down into the lumbar region and down into the buttock region
  • can see that pain refers, but isnt possible to accurately determine what level of problem the is just from where the pain is experienced