Classification of chronic pain associated with spinal cord injuries

International Spinal Cord Injury Pain Classification: part I. Background and description

“…Over the next year, the panel developed a draft classification based upon some of the major and more recent previously proposed classifications, using the electronic exchange of successive drafts. 5,9,14,16 The final draft was sent out for review by all of the major SCI and pain organizations, including: the American Spinal Injury Association (ASIA), the American Pain Society, the International Association for the Study of Pain (IASP), the International Spinal Cord Society (ISCoS), and the Academy of Spinal Cord Injury Professionals. All the organizations gave written feedback, which was reviewed by the group and incorporated as appropriate into a revised classification (see Figure 1).…”

“…The second tier (Tier 2) includes for the neuropathic and nociceptive categories various subtypes of pains identified in previous SCI pain classifications. 5,9,14,16 The third tier (Tier 3) is used to specify the primary pain source at the organ level as well as the pathology, if either is known. For the other pain category, this tier is used to specify distinct recognized pain entities or syndromes which do not fulfill the criteria for nociceptive or neuropathic pain.…”

“…5,9,14,16 Failure to find evidence of musculoskeletal pathology underlying pain, that is, located at or below the NLI or failure of the pain to respond to treatment directed at such pathology may indicate the presence of at-level SCI (neuropathic) pain or below-level SCI (neuropathic) pain (see below).…”

“…2 As classifications are built upon definitions, and prevalences of pain types are calculated based upon identified defined pain types, it should not be surprising that there are widely varying estimates of the prevalence of various types of pain after SCI. For example, the prevalence of visceral pain has been estimated to be in the range from 5 to 34%, [3][4][5] whereas the prevalence of neuropathic pain thought to be due to spinal cord damage and experienced below the level of injury has been estimated to be anywhere from 14 to 40%. [4][5][6][7] Some of the variance in the reported prevalences is presumably due to methodological aspects of study design, for example, the time that has elapsed since injury at the point when a question on the presence of pain is asked, the threshold of intensity or discomfort at which pain or severe pain is defined, and questionnaire response rates or skewed population sampling.…”

“…Neuropathic pain thought to be due to damage to the spinal cord and presenting topographically in the dermatomes below the damaged segments has been variously called spinal cord pain, phantom pain, diffuse pain, central remote pain, deafferentation pain, below level central pain and SCI pain. 5,[10][11][12][13][14][15] Such a confusion of number and nature of pain subtypes, and terms used, obviously impedes communication between clinicians, researchers and others. The authors agreed that it would be worthwhile to create a consensus classification based on international input and state-of-the-art basic and clinical scholarship.…”