Personalized Auricular Vagus Nerve Stimulation in Intractable Chronic Low Back Pain

Overview

One in five people in the general adult population suffer from chronic pain, a figure that is higher than heart disease, cancer, and diabetes combined. A majority of these patients is suffering from chronic back pain. Conventional treatment options offer only a partial response, with many people continuing to suffer severe chronic pain, despite receiving several treatments. Non-pharmacological treatments by neuromodulation represent a promising treatment modality for these patients. For instance, spinal cord stimulation blocks pain signals travelling to the brain, but requires implantation near the spine with significant clinical risks. Vagus nerve stimulation (VNS) is another neuromodulation modality proposed to alleviate chronic pain. Conventional VNS devices are implanted under the skin on the chest and the electrodes are wired to the left vagus nerve in the neck. However, aside from implantation risks, VNS is often associated with side effects such as swallowing difficulties, due to unwanted stimulation of motoric vagus nerve branches in the neck. Percutaneous auricular VNS (pVNS) is an emerging technology for stimulation of the auricular branch of the vagus nerve in the pinna of the ear. Specific electrical impulses are applied via three miniature needle electrodes located in the auricle near sensory vagus nerve fibers. Scientific data show that pVNS modulates brain circuits involved in autonomic control and pain processing. pVNS has shown positive effects in chronic low-back pain patients, in a sustainable way with a low side-effect profile. However, the optimal settings of stimulation with regards to personalization remain to be elucidated. The present prospective, open, randomized, controlled pilot study aims at evaluating the performance of pVNS treatment, using a small wearable stimulation device (AuriMod CT01), comparing personalized and non-personalized stimulation paradigms in patients with chronic low-back pain. Patients will be randomized in one of the following treatment groups (1) Group A: Stimulation with personalized stimulation parameters and amplitude, (2) Group B: Stimulation with personalized stimulation amplitude, (3) Group C: Stimulation without personalization (comparator group). Patients will be treated for 8 weeks. Patients will receive standardized pain medication including rescue medication in parallel. An additional follow-up period of 12 weeks allows to evaluate sustainable and late-time effects of treatment. Patients will use a therapy management system to monitor outcome.