title: Assessment of patient preference for constant voltage and constant current spinal cord stimulation.
abstract: OBJECTIVE
  Spinal cord stimulation devices control energy by generating either constant voltage (CV) pulses or constant current (CC) pulses. This study aimed to investigate: 1) whether patients feel differences between CV and CC stimulation; 2) if patients prefer CV or CC stimulation.
  
  
  METHODS
  Fourteen patients blinded to the type of pulse generation received 20 randomized pairs of 15-sec pulse trains (CC-CV, CV-CC, CV-CV, or CC-CC). Patients identified whether the pairs were the same or different, and if they preferred the first or second train.
  
  
  RESULTS
  There was no difference in charge-per-pulse input between CV and CC modes. Patients performed at chance level in identifying identical pairs (55.7 ± 24.1% correct, 10 trials), and slightly better in identifying different pairs (67.1 ± 25.2% correct, 10 trials). No patients correctly identified all pairs. Patients were categorized based on their performance in this task. Only three patients fell into a category where preference could be established with some confidence with respect to the group averages. Two of these patients preferred CV, while one patient preferred CC.
  
  
  CONCLUSIONS
  The lack of patient ability to discriminate in this preliminary investigation suggests that patient preference for a stimulation type should not be the key determining factor in choosing a spinal cord stimulation system.
authors: Center for Pain Control, Garland, TX, USA;             John Sasaki, M.D., Inc., Pomona, CA, USA;             Medical Advanced Pain Specialists (MAPS), Applied Research Center, Edina, MN, USA; and             Medtronic Neuromodulation, Minneapolis, MN, USA.
authors: Cristy M
authors: CM
authors: Schade
authors: John
authors: J
authors: Sasaki
authors: David M
authors: DM
authors: Schultz
authors: Nancy
authors: N
authors: Tamayo
authors: Gary
authors: G
authors: King
authors: Lisa M
authors: LM
authors: Johanek