Transcutaneous neurostimulation parameters for neuropathic radicular pain: Results from a two period crossover...

Transcutaneous neurostimulation (TENS) is commonly used in the treatment of chronic radicular pain, but without any consensus on the type of current to be delivered. The aim of this study was to compare the conventional high-frequency, low-intensity current called c-TENS with a mixed current called m-TENS, combining c-TENS with a low-frequency, high-intensity current.

This was a single-blind, two-period crossover randomized trial. Included patients had chronic (≥3months), neuropathic (dn4≥4) radicular pain of at least moderate intensity (Visual Analogic Scale [VAS]≥40mm [0-100mm]). Patients were randomized to receive either c-TENS or m-TENS first, then the other, and both during one month. The primary outcome was the level of radicular pain, measured by VAS at the end of each of the two period.

Seventy-four patients were included (mean age: 51.9±13.5years, female proportion: 65.6%). The mean duration of radicular pain was 45.2±51months and the mean radicular intensity was 67±12.5/100mm. After one month of treatment, VAS decreased to 53.9±20.1mm under c-TENS and to 53.9±21.3 under m-TENS (NS). Thirteen patients (20.3%) had a VAS<40/100 with either c-TENS or m-TENS (NS). Tolerance was the same for the two modes. Twenty-nine patients (46%) designated c-TENS as the most effective mode, and 34 patients (54%) designated m-TENS.

This study shows no difference in terms of efficacy or tolerance between c-TENS and m-TENS. There is no justification for preferring one of these two modes over the other for the treatment of chronic neuropathic radicular pain.