Can an electrical pulsed radiofrequency device relieve pain and improve function in patients with pedal diabetic neuropathy? A single-blind, randomized placebo-controlled trial.

P. Berger¹, S. Landaux²

¹University of the Witwatersrand (Faculty of Health Sciences)
²Centre for Diabetes and Endocrinology (CDE) Johannesburg, South Africa

Abstract

Can an electrical pulsed radiofrequency device relieve pain and improve function in patients with pedal diabetic neuropathy? A single-blind randomized placebo-controlled trial.

Aim: A randomised single-blind placebo study was conducted on 80 patients with pedal diabetic peripheral neuropathy in 2 cities and their surrounds in South Africa to determine if a pulsed radiofrequency current (PRF) can produce changes in the primary outcome of the DN4 Test and possibly in the BPI-short form.

Method: Patients were selected by their physicians at Centres for Diabetes and randomised into 2 groups – 40 patients each in the groups (A=Active, B =Placebo). Inclusion criteria were pedal Diabetic Peripheral Neuropathy and having a score of 4 or 4+/10 in the DN4 Test. Exclusion criteria: previous experience with the pulsed radiofrequency current and having: peripheral or spinal cord stimulator, pacemaker, metal implants and pregnancy. The DN4 was the primary objective and BPI-SF (secondary) was also tested at baseline, after 3 treatments and 3 follow-ups at 1, 3 and 6 months. Each patient had 3 treatments or a placebo once weekly for 10 mins bilaterally at the sciatic nerve in the popliteal fossa.

Results: Data were analysed using the SAS version (9.4 statistical program). Results are expressed as mean and standard deviation by groups (A=Active, B=Placebo). There were differences for age and gender in these 2 groups (Age, p=0.030, gender p=0.01) and adjustments were made where applicable. There were also differences evident regardless of age and gender. The DN4 demonstrated that between baseline and 3 treatments there was a reduction in pain and symptoms greater for the A group: p= 0.010 regardless of age and gender. Between baseline and 1 month there was a reduction in pain in both groups, but no significant difference between them p=0.10 but gender and age, nearly significant. There were no differences at 3 and 6 months. In the BPI-SF there were differences between the active and placebo groups in the worst, average and present pain with positive p values some with adjustment for age and gender.

For relations with other people, there was evidence of significant changes some regardless and some adjusted for age and gender and also relations with other people and without analgesics at baseline. There were no differences even after adjustments for age and gender for work and walking ability. None of the BPI-SF variables showed any differences when adjusting for baseline and or analgesics.

Methods

We applied External (transcutaneous) Stimulation to 35 eligible patients complaining of peripheral neuropathic pain. The procedure entailed the application of a 2Hz frequency and amplitude between 1mA and 15mA electrical stimulus (Neurotrace III, predecessor to NMS460) transcutaneously to a targeted area or nerve supplying the area of intractable pain. The duration of stimulation was 5 minutes in each case and pain scores (VAS) were recorded at 0 and 5 minutes.

Conclusion

After three treatments of PRF current, the DN4 Test demonstrates significant improvements in neuropathic pain and symptoms in certain patients with diabetic peripheral neuropathy.