PERCUTANEOUS ELECTRICAL NERVE STIMULATION BIOWAVE PRO IN CHRONIC POST-HERPETIC NEURALGIA UNRESPONSIVE TO MEDICAL TREATMENT

S. Sardi¹, L. Cancelliere¹, M. Candriella¹, A. Sala¹, R. Vaschetto² | ¹Pain Unit, University of Eastern Piedmont "A. Avogadro", Novara; ²Anesthesia and Intensive Care Unit; Department of Clinical and Experimental Medicine, University of Eastern Piedmont "A. Avogadro", Novara

INTRODUCTION
Percutaneous Electrical Nerve Stimulation (PENS) is a minimally invasive neuromodulation technique used to manage chronic pain, especially in patients unresponsive to pharmacologic therapies. PENS typically uses biphasic pulsed current with low or mixed frequencies while the BioWave PRO system uses a new technology that delivers two alternating high-frequency pulses through transcutaneous microneedle-electrodes. The passage of the current to the underlying tissue generates a low-frequency electric field that inhibits the propagation of the action potential and blocks the transmission of pain to higher centers. Current indications include Post- Herpetic Neuralgia.
METHODS
This study is a preliminary observational study. All patients provided informed consent prior to undergoing treatment with the BioWave PRO device. B-SET electrodes (each 6 cm in diameter) were placed over the area of pain. Patients were instructed to gradually increase the power output of the device during the 30-minute session until they experienced mild discomfort Inclusion criteria were: age over 18 years; chronic high-performance neuralgia unresponsive to medical therapy; pain intensity greater than 4 out of 10 on the Numeric Rating Scale (NRS). Exclusion criteria included: presence of a pacemaker or implantable cardioverter-defibrillator; epilepsy; pregnancy. Primary endpoints were i) a reduction in pain of at least 50% compared to the initial NRS score following treatment and ii) a subjective sense of well-being lasting at least 24 hours post-treatment.
RESULTS
The study population consisted of five patients (3 females, 2 males) diagnosed with chronic Post-Herpetic Neuralgia that had been unresponsive to conventional medical therapy for a minimum of six months. The mean age of participants was 72 years. Neuropathic pain was confirmed in all cases by a DN4 questionnaire score ≥4. The primary sites of treatment were thoracic (4 patients) and cervical (1 patient). Baseline pain intensity, assessed using the Numeric Rating Scale (NRS), ranged from 4 to 7. Following treatment, all patients experienced a clinically significant reduction in pain (≥50%), and the difference between pre- and post-treatment NRS scores was statistically significant (p < 0.01, paired t-test). No adverse effects were observed during or after the treatment.
CONCLUSIONS
Chronic Post-Herpetic Neuralgia is often difficult to treat only with medical therapies, BioWave PRO shows promising results in this scenario, achieving statistical significance in reducing pain by more than 50%. However, although 80% of patients experienced relief for over 24 hours, the sample size is too small to reach statistical significance (p = 0.188). This endpoint shows promising results and warrants confirmation in future studies with a larger cohort.