Multicenter, randomized, double-blinded crossover study.

Homogenous patient group: chronic, unilateral, neuropathic leg pain after back surgery.

Comparison of 1000 Hz and 30 Hz in the 30-day trial period.

There were no significant differences in the treatment effects of 1000 Hz and 30 Hz at the end of the trial period.

A majority of the patients (16/27) preferred sub-perception threshold stimulation but this was not based on their pain suppression.

Ninety-two percent of patients experienced a minimally important clinical difference (greater than 34% pain suppression).

Fifty percent of patients experienced greater than 80% pain suppression at 1 year.

Quality of life according to patient-reported outcome measures improved at 1 month and were sustained through 1 year.