Percutaneous electrical nerve stimulation: an alternative to TENS in the management of sciatica

Sciatica is a common pain problem and current pharmacologic therapies have proven inadequate for many patients. The objective of this sham-controlled investigation was to compare a novel non-pharmacologic technique, percutane ous electrical nerve stimulation (PENS), to transcutaneous electrical nerve stimulation (TENS) in the management of the radicular pain associated with sciatica. Sixty-four consenting patients with sciatica due to lumbar disc herniation were treated with PENS, TENS and sham-PENS according to a random ized, single-blinded, cross-over study. All patients had been maintained on a stable oral non-opioid analgesic regimen for at least 6 weeks prior to e ntering the study. Each treatment modality was administered for a period of 30 min three times per week for 3 weeks, with 1 week 'off' between each mo dality. Both PENS and TENS treatments were administered using a stimulation frequency of 4 Hz. The pre-treatment assessment included the health status survey short form (SF-36), as well as visual analog scales (VAS) for radic ular pain, physical activity and quality of sleep. The pain VAS was also re peated after each treatment session. At the end of each 3-week treatment bl ock, the SF-36 was repeated. After receiving all three treatment modalities , a global assessment questionnaire was completed. Both PENS (42%) and TENS (23%) were significantly more effective than the sham (8%) treatments in d ecreasing VAS pain scores. The daily oral analgesic requirements were also significantly reduced compared to the pre-treatment values with PENS (P < 0 .01) and TENS (P < 0.05). However, PENS was significantly more effective th an TENS (and sham-PENS) in improving physical activity and quality of sleep . The SF-36 evaluation confirmed the superiority of PENS (versus TENS and s ham-PENS) with respect to post-treatment functionality. In the overall asse ssment, 73% of the patients reported that PENS was the most desirable modal ity (versus 21% for TENS and 6% for sham-PENS). Finally, 71% of the patient s stated that they would be willing to pay extra to receive PENS therapy co mpared to 22% and 3% for TENS and sham-PENS, respectively. In this sham-con trolled study, we concluded that PENS was more effective than TENS when adm inistered at a stimulation frequency of 4 Hz in providing short-term pain r elief and improved functionality in patients with sciatica. (C) 1999 Intern ational Association for the Study of Pain. Published by Elsevier Science B. V.