Predicting Outcome of Transcutaneous Electrical Nerve Stimulator (TENS) in Failed Back Surgery Syndrome

The study investigates the feasibility and efficacy of Transcutaneous Electrical Nerve Stimulator (TENS) in a subgroup of patients with neuropathic pain. Those patients are suffering of neuropathic pain at the lower back and leg after spinal surgery with a predominance of pain in the leg.

Study Overview

• Status: Unknown
• Conditions: Failed Back Surgery Syndrome
• Intervention / Treatment: Device: TENS; Device: Sham-TENS

Detailed Description

Derived from folk tradition, the notion that rubbing the skin over a painful area relieves pain, found scientific support in the gate-control theory proposed by Melzack and Wall 1. Since then, electrical stimulations for pain relief have spread worldwide.

The most known technique is Transcutaneous Electrical Nerve Stimulator (TENS). Surface electrodes are placed over the lower back (paravertebral at level L1-L2) it and the stimulation is delivered at high frequency and low intensity (below pain threshold), to produce an intense activation of Ab afferents and to evoke paresthesiae that cover the painful area.

In the literature about TENS in neuropathic pain a few controlled trials (classes II-IV) were found 2-8. The most studies dealt with painful diabetic neuropathy were very-high-frequency stimulation of lower-limb muscles were found more efficacious than standard TENS and low-frequency TENS or acupuncture-like more efficacious than sham stimulations.

Studies dealing with peripheral mononeuropathies found standard TENS better than placebo.

One crossover, small-sample study (class III) in painful cervical radiculopathy found that standard TENS applied to the cervical back was better than placebo but a TENS with random frequency variation was superior7. For chronic back pain no benefit was found for TENS compared to TENS-sham using a VAS and other outcome measures, but benefit was found comparing exercise to no exercise (Class I)9. In another Class I study, TENS vs TENS-sham was studied in patients with multiple sclerosis (MS) and chronic low back pain. After correction for multiple comparisons, there were no significant differences in the VAS or the secondary measures10. Both studies were adequately powered to find at least a 20% difference in pain reduction by VAS between TENS and TENS-sham. But in other articles no benefit were found for chronic back pain treated with TENS11,12. Therefore a recent report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology did not recommend TENS for the treatment of chronic low back pain due to lack of proven efficacy but TENS should be considered for the treatment of painful diabetic neuropathy 13

In our study design, we will investigate the feasibility and efficacy of TENS in a subgroup of patients with neuropathic pain. Those patients are suffering of neuropathic pain at the lower back and leg after spinal surgery with a predominance of pain in the leg.

• Study Type: Interventional
• Enrollment (Anticipated): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Belgium
  • Vlaams Brabant
    • Brussels, Vlaams Brabant, Belgium, 1090
      • UZ Brussel

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

Inclusions:

• Age male/female patient ≥ 18 years
• Patient diagnosed with Failed Back Surgery Syndrome with at least one prior spinal surgery
• Patient with low back pain and/or pain in at least one leg
• Pain intensity at baseline assessed by VAS > 5 (50%)

Exclusion Criteria:

Exclusions:

• Formerly treated with TENS
• Several unrelated sites of pain
• Cognitive impairment
• No help to replace electrodes
• Ongoing litigation
• Psychological intervention
• Language difficulties
• No informed consent
• Existing or planned pregnancy
• Age male/female patient <18 years

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: DOUBLE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
ACTIVE_COMPARATOR: TENS; FBSS patients treated with TENS	Device: TENS; Transcutaneous Electrical Nerve Stimulator
PLACEBO_COMPARATOR: Sham-TENS; patients treated with Sham-Tens	Device: Sham-TENS; TENS without electrical output, from the outside not different from a normal TENS

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To evaluate the feasibility to use TENS devices in Failed Back Surgery Syndrome (FBSS) as a non-invasive method to treat neuropathic pain.	To evaluate the feasibility to use TENS devices in Failed Back Surgery Syndrome (FBSS) as a non-invasive method to treat neuropathic pain using pain scores, QOL scores and depression scores	1 year

Collaborators and Investigators

• Sponsor: Universitair Ziekenhuis Brussel
• Collaborators: Evenepoel Kristof; De Rudder Marc; Dokter Moens Maarten (primary investigator); Prof. dr. Cattrysse Eric; Prof. Dr. D'Haens Jean
• Investigators: Principal Investigator: Maarten Moens, M.D., Universitair Ziekenhuis Brussel

Study record dates

Study Major Dates

• Study Start: September 1, 2010
• Primary Completion (ANTICIPATED): September 1, 2011
• Study Completion (ANTICIPATED): September 1, 2011

Study Registration Dates

• First Submitted: August 19, 2010
• First Submitted That Met QC Criteria: August 19, 2010
• First Posted (ESTIMATE): August 20, 2010

Study Record Updates

• Last Update Posted (ESTIMATE): August 20, 2010
• Last Update Submitted That Met QC Criteria: August 19, 2010
• Last Verified: August 1, 2010

More Information

Terms related to this study

• Keywords: FBSS
• Additional Relevant MeSH Terms: Pathologic Processes; Postoperative Complications; Pain; Neurologic Manifestations; Disease; Back Pain; Syndrome; Failed Back Surgery Syndrome
• Other Study ID Numbers: vubmtmoensTENS