title: Efficacy of transcutaneous electrical nerve stimulation (tens) for chronic low-back pain in a multiple sclerosis population: a randomized, placebo-controlled clinical trial.
abstract: OBJECTIVE
  This study was designed to investigate the hypoalgesic effects of self-applied transcutaneous electrical nerve stimulation (TENS) on chronic low-back pain (LBP) in a multiple sclerosis (MS) population.
  
  
  METHODS
  Ninety participants with probable or definite MS (aged 21 to 78 y) presenting with chronic LBP were recruited and randomized into 3 groups (n=30 per group): (1) low-frequency TENS group (4 Hz, 200 micros); (2) high-frequency TENS group (110 Hz, 200 micros); and (3) placebo TENS. Participants self-applied TENS for 45 minutes, a minimum of twice daily, for 6 weeks. Outcome measures were recorded at weeks 1, 6, 10, and 32. Primary outcome measures included: Visual Analog Scale for average LBP and the McGill Pain Questionnaire. Secondary outcome measures included: Visual Analog Scale for worst and weekly LBP, back and leg spasm; Roland Morris Disability Questionnaire; Barthel Index; Rivermead Mobility Index; Multiple Sclerosis Quality of Life-54 Instrument, and a daily logbook. Data were analyzed blind using parametric and nonparametric tests, as appropriate.
  
  
  RESULTS
  Results indicated a statistically significant interactive effect between groups for average LBP (P=0.008); 1-way analysis of covariance did not show any significant effects at any time point once a Bonferonni correction was applied (P>0.05). However, clinically important differences were observed in some of the outcome measures in both active treatment groups during the treatment and follow-up periods.
  
  
  CONCLUSIONS
  Although not statistically significant, the observed effects may have implications for the clinical prescription and the use of TENS within this population.
authors.affiliation: Health and Rehabilitation Sciences Research Institute, University of Ulster, Jordanstown, Northern Ireland.
authors.forename: Kim
authors.initials: K
authors.lastname: Warke
authors.forename: Jamal
authors.initials: J
authors.lastname: Al-Smadi
authors.forename: David
authors.initials: D
authors.lastname: Baxter
authors.forename: Deirdre M
authors.initials: DM
authors.lastname: Walsh
authors.forename: Andrea S
authors.initials: AS
authors.lastname: Lowe-Strong
mesh_terms: D000328:Adult; D000368:Aged; D002908:Chronic Disease; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000209:etiology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications* / Q000628:therapy*; D017063:Outcome Assessment, Health Care; D015990:Placebo Effect; D004561:Transcutaneous Electric Nerve Stimulation / Q000379:methods*; D016896:Treatment Outcome