Is TENS purely a placebo effect? A controlled study on chronic low back pain

Abstract

Although high-frequency low-intensity transcutaneous electric nerve stimulation (TENS) has been extensively used to relieve low back pain, experimental studies of its effectiveness have yielded contradictory findings mainly due to methodological problems in pain evaluation and placebo control. In the present study, separate visual analog scales (VAS) were used to measure the sensory-discriminative and motivational-affective components of low back pain. Forty-two subjects were randomly assigned to 1 of 3 groups: TENS, placebo-TENS, and no treatment (control). In order to measure the short-term effect of TENS, VAS pain ratings were taken before and after each treatment session. Also, to measure long-term effects, patients rated their pain at home every 2 h throughout a 3-day period before and 1 week, 3 months and 6 months after the treatment sessions. In comparing the pain evaluations made immediately before and after each treatment session, TENS and placebo-TENS significantly reduced both the intensity and unpleasantness of chronic low back pain. TENS was significantly more efficient than placebo-TENS in reducing pain intensity but not pain unpleasantness. TENS also produced a significant additive effect over repetitive treatment sessions for pain intensity and relative pain unpleasantness. This additive effect was not found for placebo-TENS. When evaluated at home, pain intensity was significantly reduced more by TENS than placebo-TENS 1 week after the end of treatment, but not 3 months and 6 months later. At home evaluation of pain unpleasantness in the TENS group was never different from the placebo-TENS group.(ABSTRACT TRUNCATED AT 250 WORDS)

Outcome of transcutaneous electrical nerve stimulation in chronic pain: short-term results of a double-blind, randomised, placebo-controlled trial

“…Perhaps more important is the fact that our findings clearly show that TENS significantly decreased pain intensity ratings in a cumulative manner over repeated treatment sessions, in contrast to animal research, where repeated TENS administration results in gradual diminution of analgesic effect via opioid tolerance [19], but (except for the sham TENS) in line with the results of Marchand et al [10]. However, how much the pain results will improve when extending the treatment period needs to be investigated.…”

“…A 50% change in pain intensity has been used to evaluate TENS treatment effect in patients with osteoarthritis; Smith et al [9] found 50% or more relief in pain intensity in 67% and 27% of the patients treated with TENS and sham TENS respectively; treatment was applied 8 times for 20 min over a period of 4 weeks. However, Marchand et al [10] found in patients with low back pain that TENS significantly decreased intensity ratings in a cumulative manner over repeated treatment sessions. So for shorter periods of TENS treatment, less pain reduction may be expected than for longer treatment periods.…”

The amelioration of the suffering associated with spinal cord injury with subperception transcranial electrical stimulation

“…6,7,9,11 ± 13 Management of associated complaints such as sleep disturbance, 13 speci®c type of pain 2 ± 5 or depression 6,7 increases the reliance on medication, 8 some of which is contentious for long term use. 14 The most familiar non-pharmaceutical alternative for pain management, transcutaneous electrical nerve stimulation (TENS), is of limited use in chronic pain 15 such as that associated with SCI. A variant, spinal cord stimulation, has been used for 30 years, 16 but there remains a lack of consistent proof of e cacy and cost e ectiveness, and some studies 17,18 report the development of tolerance with resultant loss of analgesic e cacy.…”

The Comparison of Effectiveness of TENS and Placebo TENS in Peripheral Neuropathic Pain in Patients with Type II Diabetes Mellitus

“…It was conc lu ded that the ef fect of TENS las ted short and TENS sho uld be app li ed in a mul ti dis cip li nary ap pro ach com bi ned with ot her phar ma co lo gic agents. 13 TENS is a fre qu ently app li ed the rapy in chronic pa in alt ho ugh evi den ce for ef fec ti ve ness is inconc lu si ve. Se ve ral types of TENS exist, ba sed on dif fe rent com bi na ti ons of fre qu ency, pul se du ra tion and in ten sity.…”