The Pain Suppressive Effect of Alternative Spinal Cord Stimulation Frequencies
Condition: Failed Back Surgery Syndrome; Neuropathic Pain
MeSH terms: Neuralgia; Failed Back Surgery Syndrome
Study type: Interventional

Summary: 
      Electrical stimulation of the spinal cord (Spinal Cord Stimulation or SCS) for pain relief
      has been used for decades. It is used most commonly in patients with chronic neuropathic leg
      pain, after spinal surgery. Conventional neurostimulation is applied in frequencies of 30 to
      60 Hertz (Hz) and perceptible paraesthesias are felt. Stimulation using higher frequencies
      with sub perception paraesthesias has recently challenged the conventional form of
      neurostimulation.The high frequency stimulation appears to show better pain relief for both
      back and limb pain in comparison to low frequency SCS, and may also to be effective in some
      subjects who did not respond to low frequency SCS.
    

Detailed description: 
      Rationale:

      Electrical stimulation of the dorsal columns of the spinal cord (Spinal Cord Stimulation or
      SCS) for pain relief has been used in humans for several decades. The most common indication
      for SCS is the treatment of refractory neuropathic leg pain, particularly when these symptoms
      persist after an anatomically successful operation (Failed Back Surgery Syndrome or FBSS).

      Low frequency - conventional - SCS (LF-SCS) is applied in frequencies ranging from 30 to 60
      Hertz (Hz) and the subject feels paraesthesias in the painful area, which is considered the
      ideal situation. Recently, LF-SCS has been challenged by the development of stimulation modes
      at higher frequencies which provide pain relief at sub-perception threshold, i.e. without
      paraesthesias. A recent case series reported that High Frequency Spinal Cord Stimulation
      (HF-SCS) appears to show better pain relief for both back and limb pain in comparison to
      LF-SCS, and also to be effective in some subjects who did not respond to LF-SCS.

      Objective:

      The primary objective of this trial is to compare pain suppression in two groups of subjects
      with chronic unilateral limb pain as a result of FBSS .

      Study design:

      A prospective, double blind (subject, physician, statistician), multi-centre, randomized,
      crossover trial of SCS in the treatment of subjects with refractory neuropathic leg pain
      after back surgery.

      Study population:

      Patients with chronic neuropathic refractory unilateral leg pain

      Intervention:

      Patients will undergo neurostimulation with low and high frequency parameters, the order in
      which they receive treatment will be randomized

      Main study endpoint:

      Pain suppression in the short and long-term (24 days and 12 months)

      Nature and extent of the burden and risks associated with participation, benefit and group
      relatedness:

      Both methods of stimulation are standard clinical practice performed routinely in the study
      centres, both groups will receive this standard care. The only difference is change of
      stimulation frequency and the order in which it is applied.

      Possible benefit to the subject is that both forms of stimulation will be evaluated. This may
      lead to a better quality of life in the HF-SCS Group as result of pain relief without
      paraesthesias. Furthermore, non-responders to LF-SCS may benefit from HF-SCS.
    

Intervention name(s): Spinal Cord Stimulation; Group 1; Group 2
Intervention type(s): Device; Device; Device
Intervention description(s): Crossover design whereby subjects will undergo Spinal Cord Stimulation in two arms: low frequency stimulation and high frequency stimulation; 9 days of spinal cord stimulation at 30 Hertz and perceptible paraesthesias; 9 days of spinal cord stimulation with 1000 Hertz and sub-perception paraesthesias
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Failed Back Surgery Syndrome; Neuropathic pain; Leg Pain; Chronic Pain; Spinal Cord Stimulation; Neurostimulation