Advances in the Management of Complex Regional Pain Syndrome

Complex regional pain syndrome (CRPS) is a chronic pain condition that involves pain most commonly in the arms and legs but can affect all areas of the body. Approximately 50,000 new cases of CRPS occur annually and there remains a need for improved treatment options.

During a morning session on the final day of the 2013 American Academy of Pain Medicine annual meeting, being held April 12-14 in Fort Lauderdale, Florida, Joshua Prager, MD, MS, of the University of California in Los Angeles, moderated a session focusing on treatment options for CRPS. Prager began by discussing the International Association for the Study of Pain (IASP) CRPS treatment algorithm that includes the WHO analgesic ladder, anticonvulsants, tricyclics, free radical scavengers, vasodilatory medications, vitamin C, ketamine, neurostimulation, and neuroablation.

Salim Hayek, MD, PhD, of Case Western University in Cleveland, OH, provided an overview of the evidence available for CRPS treatment options. He said that while the disease was previously categorized into three stages, current medical practice looks at the disease as a continuum, with only 10% of cases progressing.

Hayek also discussed several pharmacologic and non-pharmacologic treatment options for CRPS. In terms of pharmacologic management, he said there is no single drug that completely addresses the overall condition. Typically, physicians should be prepared to use a variety of options to help control the pain and other symptoms associated with the condition. There is very little evidence that NSAIDs are effective for the treatment of CRPS. In addition, TNF-alpha blockers have only demonstrated some anecdotal evidence of effectiveness. However, treatment with dimethylsulfoxide 50% (DMSO) and n-acetylcysteine (NAC) has been shown to be relatively effective in the management of CRPS.While opioids can be effective in some patients with CRPS, there is very little evidence that supports the use of these drugs in this patient population. Hayek noted there is also little evidence that antidepressants aid in pain relief associated with CRPS. NMDA antagonists and ketamine have shown some efficacy in the treatment of the condition. There is very little evidence that antihypertensives work. He also said there is conflicting evidence surrounding bisphosphonates, though intravenous immunoglobulin (IVIG) has shown some promise.

In terms of interventional procedures, sympathetic blocks, continuous infusion techniques, spinal cord stimulation (SCS), bupivacaine, baclofen, and botox have all been shown to be effective to varying degrees, though highly patient-specific. However, sympathectomy has been removed from the treatment algorithm due to the high risk of neuralgia.

Prager concluded the session by reviewing several new approaches to treating CRPS, with a focus on the importance on individualizing treatment for each patient. He noted that intrathecal baclofen should be used for dystonia and provided a compelling case study that demonstrated major improvements in motor skills over a two year period. Other promising approaches currently being incorporated into the CRPS treatment algorithm include ketamine, physiological/occupational therapy, vitamin C, and SCS.

Overall, an integrated approach to the treatment of CRPS should be followed that includes rehabilitation, pain management, and psychological management. According to Prager, physicians should think about CRPS management as a continuum that requires a flexible treatment approach. They should use opioids only to help patients get through physical therapy. Physicians should find the best method of pain and/or motor control to get the patient through physical therapy, as this combination will likely lead to more successful patient outcomes.