Safety and effectiveness of percutaneous electrical nerve stimulation on pain reduction in patients suffering from neuropathic or mixed pain

Abstract

Pain is a harmful symptom, strongly influencing HRQoL and rehabilitative treatment and often refractory to pharmacological and non-pharmacological therapeutic strategies. In recent years, percutaneous electrical nerve stimulation (PENS) has been proved to be an effective procedure in the management of refractory neuropathic pain and some conditions of refractory mixed pain like low back pain. However, up to date, evidences in literature about the effectiveness of PENS in terms of pain reduction and HRQoL improvement in the rehabilitation field are scarce. Therefore, aim of our study was to evaluate safety and effectiveness of PENS on short-term pain reduction in patients suffering from neuropathic or mixed pain, non-responders to conventional therapies in a rehabilitative setting. This retrospective study was performed on a cohort of 75 adults (25 men and 50 women), mean aged 70.05 ± 14.16 years, suffering from neuropathic or mixed pain non responsive for more than 3 months to both pharmacological and non-pharmacological therapies. From 2014 to 2017, patients were treated by subcutaneous needle-electrode insertion in the sore area and return-on-skin electrode placement, both connected to a generator (AS SUPER 4 digital by TÜV Rheinland) for a 40-minute session at alternate frequencies of 2 and 100 Hz. Pain was assessed by Numerical Rating Scale (NRS) before and immediately after the treatment. Five patients experienced self- limiting and short-term pain mainly due to subcutaneous needle placement. No complication affected the continuation of the procedure. There was a significant reduction in NRS (defined as > 50%) after treatment in 70% of patients. PENS has been proven to be a safe and effective procedure in the treatment of neuropathic and mixed pain in patients non-responders to both pharmacological and non-pharmacological treatments. Its use in Physical and Rehabilitative Medicine should be encouraged and supported by other studies.