TENS may be effective for diabetic peripheral neuropathy. According to an evidence-based review in the January 12 issue of Neurology, transcutaneous electric nerve stimulation (TENS) offers little value as a treatment for chronic low back pain but may reduce pain from diabetic peripheral neuropathy. A review of two prospective, randomized, controlled clinical trials ("class I" studies) in patients with at least three months of low back pain found no evidence of a benefit in either four or six weeks of TENS, compared with sham treatment, using visual analog scale (VAS) scores to determine pain levels. Results with TENS in low back pain were conflicting in three prospective matched group cohort studies ("class II" studies). Class I evidence is considered stronger than class II evidence, suggesting that TENS is ineffective in the treatment of chronic low back pain. In patients with mild diabetic peripheral neuropathy, however, TENS produced modest reductions in VAS scores, compared with sham treatment in two class II studies, although in a lower-quality study it was found to be inferior to high-frequency muscle stimulation.