title: Factors associated with the success of trial spinal cord stimulation in patients with chronic pain from failed back surgery syndrome.
abstract: OBJECTIVE
  Spinal cord stimulation (SCS) is an effective means of treatment of chronic neuropathic pain from failed back surgery syndrome (FBSS). Because the success of trial stimulation is an essential part of SCS, we investigated factors associated with success of trial stimulation.
  
  
  METHODS
  Successful trial stimulation was possible in 26 of 44 patients (63.6%) who underwent insertion of electrodes for the treatment of chronic pain from FBSS. To investigate factors associated with successful trial stimulation, patients were classified into two groups (success and failure in trial). We investigated the following factors : age, sex, predominant pain areas (axial, limb, axial combined with limbs), number of operations, duration of preoperative pain, type of electrode (cylindrical/paddle), predominant type of pain (nociceptive, neuropathic, mixed), degree of sensory loss in painful areas, presence of motor weakness, and preoperative Visual Analogue Scale.
  
  
  RESULTS
  There were no significant differences between the two groups in terms of age, degree of pain, number of operations, and duration of pain (p>0.05). Univariate analysis revealed that the type of electrode and presence of severe sensory deficits were significantly associated with the success of trial stimulation (p<0.05). However, the remaining variable, sex, type of pain, main location of pain, degree of pain duration, degree of sensory loss, and presence of motor weakness, were not associated with the trial success of SCS for FBSS.
  
  
  CONCLUSIONS
  Trial stimulation with paddle leads was more successful. If severe sensory deficits occur in the painful dermatomes in FBSS, trial stimulation were less effective.
authors: Department of Neurosurgery, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors: Byung-Chul
authors: BC
authors: Son
authors: Department of Neurosurgery, St. Vincent's Hospital, The Catholic University of Korea College of Medicine, Suwon, Korea.
authors: Deok-Ryeong
authors: DR
authors: Kim
authors: Department of Neurosurgery, St. Vincent's Hospital, The Catholic University of Korea College of Medicine, Suwon, Korea.
authors: Sang-Won
authors: SW
authors: Lee
authors: Department of Neurosurgery, Yeouido St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors: Chung-Kee
authors: CK
authors: Chough
keywords: Chronic pain; Failed back surgery syndrome; Spinal cord stimulation; Spinal surgery