P-074 - (Poster #74) Neuromodulation Reinvented: A Promising Game-Changer in Complex Regional Pain Syndrome (CRPS) Pain Management

Complex Regional Pain Syndrome (CRPS) is a chronic pain disorder affecting a specific body region, typically the distal extremities. Severe pain along with sensory changes, swelling, motor impairments with limited range of motion, autonomic symptoms with vasomotor instability, trophic changes to the skin, and patchy bone demineralization characterize it. CRPS often begins after a fracture, soft tissue injury, or surgery. The exact cause of CRPS remains unknown, but proposed mechanisms involve the peripheral and central nervous systems, including classic inflammation, neurogenic inflammation, and maladaptive changes in pain and somatosensory processing perception (Central Sensitization).

One of the most notable disabling symptoms is chronic pain, which can manifest as spontaneous or evoked regional pain that is disproportionate in time or severity compared to the expected typical course of any known trauma or lesion. The pain is regional and usually more intense in the distal areas, presenting with abnormal sensory, motor, sudomotor, vasomotor, and/or trophic findings. Its progression can vary over time. The estimated incidence of CRPS ranges from approximately 5 to 26 per 100,000 individuals per year in population-based studies in the United States.

Purpose/Objectives:

A multidisciplinary approach is recommended for managing CRPS. The goal is to restore function in the affected limb, minimize pain, and improve quality of life while reducing side effects.

Current treatment modalities include physical and occupational therapy, psychological and behavioral therapy, and pharmacotherapies such as NSAIDs, anticonvulsants, antidepressants, bisphosphonates, topical creams, and experimental treatments like calcitonin, steroid therapy, alpha-adrenergic antagonists/agonists, ketamine infusion, and IVIG. The use of opioids for chronic non-cancer pain has become contentious due to the lack of high-quality data supporting their efficacy in treating CRPS. Interventional options for refractory pain include trigger point injections, sympathetic nerve blocks, spinal cord and peripheral nerve stimulation, dorsal root ganglion stimulation, and sympathectomy. However, the prognosis for CRPS can be uncertain, with a 10-30 % recurrence rate, significantly impacting daily activities, quality of life, and productivity and posing a considerable economic burden on healthcare systems.

Methods:

We present a case report of a 56-year-old male with CRPS type 1, suffering for over 20 years, who was successfully managed through a multidisciplinary approach with implementation of a Novel Non-invasive Neuromodulation therapy as a drug-free adjunctive treatment.

The patient presented with intractable pain and discomfort in both lower extremities, characterized by severe pain, edema, vasomotor instability, and limitations in range of motion at the ankles, along with skin and toenail changes despite on treatment with lidocaine patches, antidepressants, and chronic opioid therapy. His symptoms began in his 20’s following repeated marathon and cycling activities, which led to bilateral compartment syndrome requiring surgical release. Initial treatments, including NSAIDs, anticonvulsants, antidepressants, physical therapy, and conventional TENS therapy, were ineffective. He continued experiencing chronic daily pain, swelling, and limited range of motion at the ankles, along with skin changes that contributed to his disability. His daily pain scale averaged between 7 and 9 out of 10. Examination findings included erythema, edema, hair loss, toenail atrophy, hyperalgesia below the knee to toes, and reduced ankle range of motion, all of which interfered with daily functioning and quality of life. Subsequently, neuromodulation therapy was added as an adjunctive treatment to current treatment.

Results:

Non-invasive, Neuromodulation therapy was applied 2-4 times daily for 5 to 10 minutes per session to both lower extremities, with additional use for breakthrough symptoms (patient control demand use). This significantly improved pain severity, frequency, and duration, consistently reducing the pain level to 1-2 out of 10. He also reported immediate relief from breakthrough pain, when necessary, within 15 minutes. His range of motion improved by 80%, accompanied by reduced swelling and better dorsiflexion, which enhanced his ambulation ability and led to functional improvements. There was a notable reduction in vasomotor instability, edema and erythema levels. On average, symptom relief lasted up to 8 hours without any sudden rebound of symptoms. Over six months, the patient reported consistent and sustained improvements in pain control, symptoms, general activity and quality of life.

This novel Neuromodulation device delivers electric nerve stimulation transcutaneously (Non-invasive manner). It is a patented technology and is FDA-cleared for intractable pain relief. When applied over the symptomatic area, it discharges electric stimulus through the skin to underlying nerve-muscle fibers, altering and/or blocking pain signals to sensory fibers in the spinal cord and in the brain. Its unique design with fixed electrodes allows the patient to “press and hold or glide along the length of extremities,” giving it a tremendous advantage over conventional TENS devices that work with skin patches, rendering insufficient superficial treatment. The design allows the patient to apply therapeutic stimulation in a targeted application over the pain areas, either by themselves or with assistance from a caregiver for home use.

It is postulated to act by modulating pain relieving endogenous opiate pathways, inhibiting excitatory neurotransmitters, and enhancing the inhibitory pathway via the modulation of ascending and descending fibers, the release of neurotransmitters to restore the central pain modulation by central inhibition.  Thus, pain relief and control of vasomotor symptoms can be achieved via modulation of these peripheral and central pain relief mechanisms.

Conclusions/Implications for future research and/or clinical care:

This case report illustrates the potential role of a new CP Relief Wand (Rx) / Solis Pain Relief System (OTC), a novel version of TENS, both as a drug-free alternative and/or adjunctive to pharmacological management for the management of CRPS. This modality can be drug-sparing and can be applied easily at home for daily chronic use and breakthrough symptoms (patient control demand use) to personalize the treatment.  It can be addition to the multidisciplinary approach for the early chance of clinical recovery in a cost-effective manner. It can also complement ongoing physical and occupational therapy to maintain range of motion, prevent contractures, and minimize drug potential side effects.  Improvement in pain, edema, range of motion, and vasomotor instability can complement and make it easier for the patient to participate in gentle exercise, strengthening, functional activities, and gait retraining, facilitating self-management of the condition.  This may also prevent evolving of early stages of CRPS into a chronic refractory condition, avoiding the need for potentially expensive further interventional invasive procedures, narcotic dependence and its long-term implications and long-term disability. Further studies with a larger sample size could be considered.