title: Phenotypes and predictors of pain following traumatic spinal cord injury: a prospective study.
abstract: Pain is a serious consequence of spinal cord injury (SCI). Our aim was to investigate the temporal aspects of different types of pain following traumatic SCI and to determine possible predictors of neuropathic pain. Prospective data on 90 patients were collected at 1, 6, and 12 months after traumatic SCI. The patients completed questionnaires on pain severity, descriptors, and impact and underwent clinical examination with bedside sensory testing. Eighty-eight patients completed the 12-month follow-up. Approximately 80% of patients reported any type of pain at all 3 time points. Neuropathic pain related to SCI increased over time, and musculoskeletal pain decreased slightly, with both being present in 59% of patients at 12 months; other neuropathic pain not related to SCI and visceral pain were present in 1 to 3%. At-level neuropathic pain present at 1 month resolved in 45% and below-level pain resolved in 33%. Early (1 month) sensory hypersensitivity (particularly cold-evoked dysesthesia) was a predictor for the development of below-level, but not at-level, SCI pain at 12 months. In conclusion, the present study demonstrates phenotypical differences between at-level and below-level SCI pain, which is important for future studies aiming to uncover underlying pain mechanisms.
  
  
  CONCLUSIONS
  The finding that early sensory hypersensitivity predicts later onset of below-level central neuropathic pain may help to identify patients at risk of developing neuropathic pain conditions after traumatic spinal cord injury. Information about onset of pain may help to identify different phenotypes in neuropathic pain conditions.
authors.affiliation: Danish Pain Research Center, Aarhus University, Aarhus, Denmark. Electronic address: finnerup@ki.au.dk.
authors.forename: Nanna Brix
authors.initials: NB
authors.lastname: Finnerup
authors.affiliation: Department of Clinical Sciences, Karolinska Institutet, Danderyd Hospital, Stockholm, Sweden.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Norrbrink
authors.affiliation: Department of Neurology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Trok
authors.affiliation: Department of Neurology, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Piehl
authors.affiliation: Spinal Cord Injury Unit, Viborg Hospital, Viborg, Denmark.
authors.forename: Inger Lauge
authors.initials: IL
authors.lastname: Johannesen
authors.affiliation: Department of Neurosurgery, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Jens Christian
authors.initials: JC
authors.lastname: Sørensen
authors.affiliation: Danish Pain Research Center, Aarhus University, Aarhus, Denmark; Department of Neurology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Troels Staehelin
authors.initials: TS
authors.lastname: Jensen
authors.affiliation: Department of Clinical Sciences, Karolinska Institutet, Danderyd Hospital, Stockholm, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Werhagen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006930:Hyperalgesia / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology*; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology*; D010523:Peripheral Nervous System Diseases / Q000503:physiopathology; D010641:Phenotype; D011237:Predictive Value of Tests; D015995:Prevalence; D011446:Prospective Studies; D013119:Spinal Cord Injuries / Q000150:complications* / Q000453:epidemiology; D013997:Time Factors; D055815:Young Adult
keywords: Spinal cord injury; allodynia; central pain; neuropathic pain; sensory processing