title: Usefulness of laser-evoked potentials and quantitative sensory testing in the diagnosis of neuropathic spinal cord injury pain: a multiple case study.
abstract: METHODS
  A retrospective study.
  
  
  OBJECTIVE
  The aim of this study was to investigate the contribution of laser-evoked potentials (LEPs) and quantitative sensory testing (QST) to the diagnosis of neuropathic pain in patients with spinal cord injury (SCI) and inconclusive magnetic resonance imaging (MRI) findings.
  
  
  METHODS
  A multidisciplinary pain center.
  
  
  METHODS
  QST (DFNS protocol) and Tm-YAG-laser stimulation of the skin were applied within the pain site corresponding with dermatomes of altered sensation. Available MRI scans were reviewed.
  
  
  RESULTS
  Thirteen individuals (50±16 years) with SCI were examined. In four cases with no detectable neural lesion on MRI, all QST but three LEP were abnormal. In four patients with poorly defined spinal lesion on MRI, all QST but three LEP only were abnormal. In four cases where pain was not matching adequately with MRI lesions, all patients had abnormal LEP and QST. In one patient showing a spinal cord atrophy, LEP was normal but QST was abnormal. Findings supported the diagnoses at-level (n=5) and below-level (n=8) SCI pain. Spinothalamic tract function assessed by LEP was normal in three cases, but QST was abnormal in all cases.
  
  
  CONCLUSIONS
  As QST is a psychophysical examination depending on patient cooperation, we suggest that the combination of QST and LEP might be a valuable diagnostic tool to detect lesions of the somatosensory system in a subgroup of patients with neuropathic spinal cord injury pain and inconclusive MRI findings.
authors.affiliation: Centre for Pain Medicine, Swiss Paraplegic Centre, Nottwil, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Landmann
authors.affiliation: Department of Radiology, Swiss Paraplegic Centre, Nottwil, Switzerland.
authors.forename: M F
authors.initials: MF
authors.lastname: Berger
authors.affiliation: Centre for Pain Medicine, Swiss Paraplegic Centre, Nottwil, Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Stockinger
authors.affiliation: HESAV-School of Health Sciences, University of Applied Sciences and Arts Western Switzerland (HES-SO), Lausanne, Switzerland.
authors.forename: E
authors.initials: E
authors.lastname: Opsommer
mesh_terms: D005260:Female; D006801:Humans; D066331:Laser-Evoked Potentials; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009437:Neuralgia / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology*; D010147:Pain Measurement; D011601:Psychophysics; D012189:Retrospective Studies; D012867:Skin / Q000503:physiopathology; D013119:Spinal Cord Injuries / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*