Single-center, double-blinded, placebo controlled, randomized study comparing Active to SHAM ESStim™ in 20 patients. Inclusion Criteria:  presence of chronic DNP (involving at least one foot), which is resistant to first-line therapies, for at least six months with Visual Analog Score (VAS) Pain score 4.0 or greater on a 10-point scale. Exclusion criteria: unstable pain, history of epilepsy, structural brain lesions, substance abuse, and pregnancy. 

20 patients were randomized (10 Active, 10 SHAM), and stimulation was provided for 5 sessions, 20 min/day, over a 1-week period. Assessments occurred at baseline, following stimulation, and at follow-ups 2-, 4-, and 6-weeks following stimulation. Assessments included:  Quantitative Sensory Testing (QST), Safety, Biomechanical, Global Assessments, and Pain Questionnaires (VAS, VRS pain, MPI, BPI-DPN). Univariate analysis (e.g., ANOVA) was applied (p<0.05). 

Primary endpoint (VAS pain): Active ESStim showed a clinically and statistically significant improvement (2.2-point vs. SHAM’s 1.1-point reduction; and a 39 % reduction vs. 19% for SHAM averaged from the last treatment session through the last follow up). Clinically and statistically significant effects observed across pain questionnaires, quality of life assessments, QST, and biomechanical assessments. Concurrently, 30% Active patients demonstrated a reduced analgesic use vs. no changes in the SHAM group. There were no differences in safety measures between groups. 

Our results suggest that ESStim™ is a safe and efficacious therapy for the treatment of chronic DNP.