Classification of MS-associated pain

Epub: Truini et al.  A mechanism-based classification of pain in multiple sclerosis. J Neurol. 2012 Jul 4.

Pharmacological treatment of pain in MS is challenging due to the many underlying mechanisms. Few controlled trials show adequate pain control in this population. Emerging evidence suggests that pain might be more effectively classified and treated according to symptoms and underlying mechanisms. The new mechanism-based classification proposed here distinguishes nine types of MS-related pain: 

  1. trigeminal neuralgia and Lhermitte's phenomenon (paroxysmal neuropathic pain due to ectopic impulse generation along primary afferents)

    trigeminal nerve = nerve to that supplies sensation to the face
    paroyxmal = brief period of pain
    neuropathic = arising from damaged nerves
    ectopic = an electrical signal arising from the incorrect location
    afferents = sensory fibres
  2. ongoing extremity pain (deafferentation pain secondary to lesion in the spino-thalamo-cortical pathways)

    deafferentation - dissconnection of the sensory fibres
    spino-thalamo-cortical  - sensory pathway from the spinal cord (spino) to the thalamus (thalmo), which the deep gray matter in the center of the brain, to the cortex (surface of brain) were we perceive the sensation.
  3. painful tonic spasms and spasticity pain (mixed pains secondary to lesions in the central motor pathways but mediated by muscle nociceptors)

    tonic - continous contraction of muscles
    nociceptor - pain receptors
  4. pain associated with optic neuritis (nerve trunk pain originating from nervi nervorum)

    small nerves that sense pain in covering of larger nerves
  5. musculoskeletal pains (nociceptive pain arising from postural abnormalities secondary to motor disorders)
  6. migraine (nociceptive pain favored by predisposing factors or secondary to midbrain lesions)

    midbrain - the upper part of the midbrain
  7. treatment-induced pains

Identification of various types of MS-related pain will allow appropriate targeted pharmacological treatment and improve clinical practice.


"This is a useful clinical classification and provides a framework to treat pain. Different pain mechanisms require different strategies to treat them. You may recall in a recent survey that pain was way up the list of symptoms that MSers complained about and was a common reason for poor sleep. So this issue is not a trivial one."

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