title: Effects of Spinal Cord Stimulation on Pain Thresholds and Sensory Perceptions in Chronic Pain Patients.
abstract: OBJECTIVE
  Spinal cord stimulation (SCS) has been in clinical use for nearly four decades. In earliest observations, researchers found a significant increase in pain threshold during SCS therapy without changes associated with touch, position, and vibration sensation. Subsequent studies yielded diverse results regarding how SCS impacts pain and other sensory thresholds. This pilot study uses quantitative sensory testing (QST) to objectively quantify the impact of SCS on warm sensation, heat pain threshold, and heat pain tolerance.
  
  
  METHODS
  Nineteen subjects with an indwelling SCS device for chronic pain were subjected to QST with heat stimuli. QST was performed on an area of pain covered with SCS-induced paresthesia and an area without pain and without paresthesia, while the SCS was turned off and on. The temperature at which the patient detected warm sensation, heat pain, and maximal tolerable heat pain was used to define the thresholds.
  
  
  RESULTS
  We found that all three parameters, the detection of warm sensation, heat pain threshold, and heat pain tolerance, were increased during the period when SCS was on compared with when it was off. This increase was observed in both painful and non-painful sites.
  
  
  CONCLUSIONS
  The observed pain relief during SCS therapy seems to be related to its impact on increased sensory threshold as detected in this study. The increased sensory threshold on areas without pain and without the presence of SCS coverage may indicate a central (spinal and/or supra-spinal) influence from SCS.
authors.affiliation: MGH Center for Translational Pain Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Shihab U
authors.initials: SU
authors.lastname: Ahmed
authors.affiliation: MGH Center for Translational Pain Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: MGH Center for Translational Pain Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Lucy
authors.initials: L
authors.lastname: Chen
authors.affiliation: MGH Center for Translational Pain Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Kristin
authors.initials: K
authors.lastname: St Hillary
authors.affiliation: MGH Center for Translational Pain Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Abigail
authors.initials: A
authors.lastname: Cohen
authors.affiliation: MGH Center for Translational Pain Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Trang
authors.initials: T
authors.lastname: Vo
authors.affiliation: MGH Center for Translational Pain Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Mary
authors.initials: M
authors.lastname: Houghton
authors.affiliation: MGH Center for Translational Pain Research, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Jianren
authors.initials: J
authors.lastname: Mao
mesh_terms: D000328:Adult; D000368:Aged; D059350:Chronic Pain / Q000503:physiopathology* / Q000628:therapy*; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008875:Middle Aged; D059408:Pain Management; D017288:Pain Threshold / Q000502:physiology*; D010465:Perception / Q000502:physiology*; D010865:Pilot Projects; D062187:Spinal Cord Stimulation / Q000379:methods*; D016896:Treatment Outcome
keywords: Pain; quantitative sensory testing (QST); spinal cord stimulation (SCS)