Mechanisms of neural pain in leprosy

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Mechanisms of neural pain in leprosy

• Dr Aki Hietaharju, MD, PhD
• Pain Clinic, Department Of Neurology
• Tampere University Hospital
• Tampere, Finland

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Greetings from Tampere, Finland!
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Graveyard of the Seili island leprosarium, 17th
Century, Finland
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Pain terminology

• Chronic pain
• pain that persists after resolution of an acute
  injury (gt 3 or gt 6 months)
• Categories of chronic pain
• nociceptive pain
• neuropathic pain
• psychogenic pain
• pain of unknown origin

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Pain terminology

• Nociceptive pain
• pain due to receptor stimulation (nociceptors) by
  processes causing tissue injury
• somatic pain (activation of somatic primary
  afferents e.g. pain in arthritis)
• visceral pain (activation of afferent receptors
  located in viscera i.e. bile duct blockage)

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Pain terminology

• Neuropathic pain
• pain initiated or caused by a primary lesion or
  dysfunction in the peripheral or central nervous
  system
• Neurogenic pain
• pain initiated or caused by a primary lesion,
  dysfunction, or transitory perturbation in the
  peripheral or central nervous system
• International Association for the Study of Pain
  1994

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Neuropathic Pain Pain initiated or caused by a
primary lesion or dysfunction in the nervous
system (either peripheral or central nervous
system)1
Nociceptive Pain Pain caused by injury to body
tissues (musculoskeletal, cutaneous or
visceral)2
Mixed Pain Pain with neuropathic and
nociceptive components

• Examples
• Peripheral
• Postherpetic neuralgia
• Trigeminal neuralgia
• Diabetic peripheral neuropathy
• Postsurgical neuropathy
• Posttraumatic neuropathy
• Central
• Poststroke pain
• Common descriptors2
• Burning
• Tingling
• Hypersensitivity to touch or cold

• Examples
• Low back pain with radiculopathy
• Cervical radiculopathy
• Cancer pain
• Carpal tunnel syndrome

• Examples
• Pain due to inflammation
• Limb pain after a fracture
• Joint pain in osteoarthritis
• Postoperative visceral pain
• Common descriptors2
• Aching
• Sharp
• Throbbing

1. International Association for the Study of
Pain. IASP Pain Terminology. 2. Raja et al. in
Wall PD, Melzack R (Eds). Textbook of pain. 4th
Ed. 1999.11-57
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Pain terminology

• Paresthesia an abnormal sensation (spontaneous
  or evoked)
• Dysesthesia an unpleasant abnormal sensation
  (spontaneous or evoked)
• Allodynia pain due to a stimulus, which does not
  normally provoke pain
• Hyperalgesia an increased response to a stimulus
  which is normally painful
• Hyperesthesia increased sensitivity to
  stimulation