When patients living with chronic pain are referred to pain management specialists, it is often because they have already tried multiple therapy options without finding meaningful relief. For those diagnosed with complex regional pain syndrome {CRPS} or who suffer from focal limb pain, identifying efficacious therapeutic solutions can become even more challenging.

Unfortunately, chronic pain is far too common. According to the Institute of Medicine1, an estimated 100 million Americans are affected by chronic pain. Neuropathic pain, including CRPS, represents one of the most prevalent yet undertreated chronic pain conditions currently facing patients today, with an estimated 3 -4.5 percent of the global population suffering from the condition2.

Patients struggling with chronic pain may also present with co-occurring conditions affecting their quality of life such as poor sleep, inactivity, or depression and anxiety, which may strain their personal relationships3. The overall impact on American society is staggering, with health economists from John Hopkins University in Baltimore estimating that Americans spend approximately $635 billion annually on the direct and indirect costs associated with managing chronic pain4.

CRPS3CRPS: The Facts

“Our understanding of CRPS continues to evolve,” said Dr. Timothy Lubenow, a professor of anesthesiology and chief, section of pain medicine at Rush University Medical Center. “It is believed to develop along skin, nerve and skeletal muscle after trauma or injury, thought to be caused by a malfunction of the central and peripheral nervous systems that affect the way pain signals are sent from the brain and spinal cord to the rest of the body.”

Often characterized by prolonged or excessive focal pain in the limbs, CRPS can cause mild or dramatic changes in skin color and temperature, and swelling in the affected area.

There are two types of CRPS: Type I and Type II. Type I, previously called reflex sympathetic dystrophy (RSD) syndrome, occurs following an injury or illness that didn’t directly damage the nerves in the affected area.5 The diagnosis of CRPS Type II, previously called peripheral causalgia, follows a specific nerve injury.6

CRPS, although certain tests can rule out other conditions like Lyme disease or a blood clot,” said Lubenow. “Diagnosis is made by exam and review of the patient’s history and symptoms.”

Lubenow went on to explain that the disease varies in duration and severity.

“Research suggests many cases are relatively mild and patients recover gradually over time. However, in severe cases patients may require more aggressive Lubenow.

CRPS Preliminary Treatments

Similar to other chronic pain conditions, there is no single cure for CRPS, but treatment often involves a combination of approaches that can provide meaningful relief. Exercise, in the form of rehabilitation therapy, can improve flexibility, strength and blood flow .7 Occupational therapy helps patients improve their functioning with daily tasks.8 Psychotherapy can be critically important for chronic pain patients and their families.9 According to the National Institute on Neurological Disorders and Stroke (NINDS), patients with CRPS may develop depression, anxiety or post-traumatic stress disorder, which can make their pain and physical rehabilitation more difficult. Some patients benefit from learning biofeedback techniques, which help them become more aware of their body and relieve pain.10

Medication, such as non-steroidal anti-inflammatory drugs, including aspirin, ibuprofen and naproxen may be prescribed, especially in the early stages of the disease. Topical analgesics can reduce hypersensitivity11, while corticosteroids treat inflammation, swelling and edema12. A sympathetic nerve block, delivered by injection near the spine, can provide temporary relief and improve blood flow for some patients.13 A sympathectomy is a treatment that has been recommended in the past sometimes for those who show a strong response to sympathetic nerve blocks.14 This has not been shown to have a good sustained long-term response. As a last resort patients may try relief from intrathecal drug pumps, which place pain-relieving medication directly into the fluid surrounding the spinal cord.

NEUROSTIMULATION

Spinal cord stimulation (SCS), a form of neurostimulation, is a proven pain therapy that has been recommended by doctors to manage chronic pain and improve quality of life. SCS systems are approved or cleared by the U.S. Food and Drug Administration (FDA) for the management of chronic pain. It has been used to manage pain that comes from failed back surgery syndrome (FBSS) or post-laminectomy syndrome and other neuropathies.

Neurostimulation, however, is not a cure for what is causing the pain and does not treat specific diseases. Instead, it is a therapy that’s designed to mask pain by blocking pain signals before they reach the brain. While neurostimulation helps most patients receive at least some reduction in pain, not everyone responds in the same way. Complications from neurostimulation may include painful stimulation, loss of pain relief, and certain surgical risks (e.g. paralysis). Patients should be sure to discuss the risks and benefits of neurostimulation with a doctor.

CRPS2DORSAL ROOT GANGLION NEUROSTIMULATION THERAPY
FDA Approved for CRPS

A new type of neurostimulation, called dorsal root ganglion (DRG) therapy, received FDA approval in February 2016 for the treatment of adults with caused by CRPS of the lower limbs. The DRG is a spinal structure densely populated with sensory nerves that transmit information to the brain via the spinal column. The ACCURATE IDE study demonstrated DRG therapy provided superior pain relief in patients with chronic lower limb pain compared to traditional SCS therapy15.

Results from the clinical study, which is the largest study to date evaluating patients suffering from neuropathic chronic intractable pain associated with CRPS or peripheral causalgia, showed a statistically significant number of patients receiving DRG stimulation achieved meaningful pain relief and greater treatment success at three and 12-month intervals compared to patients receiving traditional SCS.

CRPS4“The latest DRG therapy delivers a form of neurostimulation that stimulates the dorsal root ganglion, giving physicians the ability to directly treat the specific areas of the lower limbs where the pain occurs,” said Lubenow. “As a result, DRG therapy is a unique therapeutic approach that provides pain relief to patients with neuropathic conditions who have tried multiple treatment options without receiving adequate pain relief and who are underserved by traditional SCS.”

While DRG therapy offers an exciting new therapy modality to treat CRPS of the lower extremities, traditional SCS remains clinically efficacious for other types of chronic pain. Anyone interested in DRG therapy or SCS should consult with their physician to discuss therapy options and personalize their chronic pain management plan.

PRIOR TO USING THE AXIUMTM NEUROSTIMULATOR SYSTEM, PATIENTS SHOULD REVIEW THE USER’S MANUAL FOR A COMPLETE LISTING OF INDICATIONS, CONTRAINDICATIONS, WARNINGS, PRECAUTIONS, POTENTIAL ADVERSE EVENTS AND DIRECTIONS FOR USE.

RESEARCH AND EMERGING THERAPIES

Although CRPS still remains somewhat unknown, there is continued research being conducted to better understand this disease. NINDS continues to support research to develop new therapies designed to limit symptoms and disability associated with CRPS. For example, earlier research suggests that CRPS is supported by the body’s natural immune response. According to the NINDS, researchers seeking to understand how CRPS develops want to further understand immune system activation and peripheral nerve signaling. Emerging treatments cited by NINDS include hyperbaric oxygen therapy, intravenous ketamine and low-dose intravenous immunoglobulin.

CHANGING THE FACE OF CRPS WITH DRG THERAPY

Patients with CRPS are often underserved by conventional medical management and many interventional pain procedures. The recent approval of DRG therapy ensures these patients have access to a superior therapeutic approach for managing difficult-to-treat chronic pain of the lower limbs in adult patients with CRPS.

Discover more and find a DRG pain specialist near you by visiting www.sjm.com/painpathways. {PP}

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