What is Complex Regional Pain Syndrome?

Imagine a medical scenario when severe burning pain develops in an area of your body and starts spreading over a limp usually traveling to the opposite extremity or in other parts progressively becoming incapacitating and taking over your life.

Enter the mysterious clinical world of complex regional pain syndromes.

Complex regional pain syndrome (CRPS) is a chronic pain condition that typically affects a limb, like a leg or an arm usually as a result of an injury. Damage or malfunction to the peripheral or central nervous system is what is believed to cause complex regional pain syndrome. In most cases, the condition is triggered by a clear history of trauma or injury. The most common triggers are fractures, sprains/strains, soft tissue injury (such as burns, cuts, or bruises), limb immobilization (such as being in a cast), surgery, or even minor injuries such as needle stick or stepping on a nail. CRPS represents an abnormal response that magnifies the effects of the injury.

This condition is not common. In fact, it is difficult to diagnose and is historically tricky to treat.

Women are more likely to suffer than men, with the average age of sufferers of both gender between the ages of 40-60.

The affected area is not only extremely painful but other symptoms can include a change of body temperature, discoloration, and swelling in the affected area.

CPRS can be divided into two types: CRPS-I and CRPS-II.

CRPS I is the most common type and likely occurs due to trauma to an area. This type also produces vasomotor disturbances (changes in skin color and temperature, like a hot flash).
CRPS II occurs after a direct and specific nerve injury and is much less common.

Symptoms of CRPS

The hallmark symptoms of CRPS is allodynia and hyperpathia. Allodynia is a condition where a pain is produced by stimulus that is usually not painful (such as touching the skin with a feather or having pain when air touches the skin). Hyperpathia also known as hyperalgesia is a condition when a Usually painful stimulus causes much more pain than it would be typically produced (a minor scratch feeling like a stabbing pain).

Overall long-term pain is always present and constant feeling of things such as pins-and-needles as burning throbbing scalding severe penetrating radiating intolerable pain with the previously mentioned hallmark characteristics.

Pain has been known to spread, even if the affected area is only a hand or even finger. While this is rare, complex regional pain syndrome may spread to other extremities, such as the opposite limb or other area of the body. Over time, if CRPS is not treated, symptoms can become irreversible.

Other symptoms of CRPS can include:

Skin discoloration
Increased sensitivity to cold or pressure
Edema (Swelling) in the affected extremities
Temperature changes
Changes in hair or nail growth
Increased joint immobility or inflexibility
Muscular atrophy (i.e. loss of muscular tone or strength)
Muscular spasticity
Impaired mobility in the affected body part(s)

Diagnosis and Treatment

Diagnosis

CRPS is diagnosed based on a patient’s medical history and present symptoms. It is especially difficult to diagnose because the symptoms are common to other conditions as well. As a person’s symptoms improve, it is even more difficult to diagnose.

Certain tests are used to rule out other disorders and conditions that display similar symptoms, such as arthritis, Lyme disease, a clotted vein, or a general muscle disease. These tests can provide your physician with clues about what is causing your pain. A careful examination should be performed to determine if an injury is the root cause of the pain – the key feature to CRPS. Thorough examinations help assess the pain and determine if other treatable conditions are present and not ignored.

Imaging tests such as magnetic resonance imaging or triple-phase bone scans may be used to confirm a diagnosis. CRPS is often related to a process where certain cells break down bone and release calcium into the blood. However, this symptom can be caused by other diseases as well. X-Rays are used to show a loss of minerals from your bones. This is common in later phases of the disease. Sympathetic nervous systems tests look for disturbances in your sympathetic nervous system by using thermography to measure your skin temperature and blood flow. Other tests can measure the amount of sweat on your limbs. Irregular results can lead to an accurate prognosis of complex regional pain syndrome.

Treatment Options

The goal of treatments is to lower the intensity of pain, avoid spreading of the symptoms, and interrupt the progression of the disease, while at the same time optimizing the patient’s functional capacity. Treatment of CRPS can be sometimes extremely difficult. The stage of CRPS different treatment options are available.

Therapies include:

Physical Therapy: Physical therapy is used to keep the painful body part moving to increase blood flow. Exercise helps increase flexibility, builds strength, and improves the function of the affected area.
Nerve Blocks: Sympathetic nerve blocks can provide relief from pain and act as both diagnostic and therapeutic modalities sometimes if offered early with short to medium term effects.
Medications: Various medications are used to help reduce pain. Anti-neuropathic medications usually prescribed for neuropathic pain such as gabapentin or Lyrica can be used as well as other medications such as Cymbalta, try cyclic antidepressant such as amitriptyline and nortriptyline, anti-inflammatories such as Naprosyn Celebrex and others. Opioids are notoriously ineffective for sympathetically mediated pain and especially CRPS and although they represent a common choice for a lot of physicians may have more risks than long-term benefits including the risks of addiction dependence and tolerance as well as long-term adverse effects into pretty much all major organ systems.
Biofeedback: Biofeedback techniques help you become more aware of your body so you can train it to relax and reduce pain. This involved being hooked up to an electrical sensors that measure your bodily functions like heart rate. This information helps train your mind and body to understand your pain on a deeper level.

The Important Role of Neuromodulation for the Treatment of CRPS

There are two distinct types of non-pharmacological neuromodulation treatments applicable in the treatment of CRPS

Dorsal Root Ganglion Stimulation (DRG): DRG Stimulation utilizes a small implantable device similar to a heart pacemaker to modify pain signals before they reach your brain. It targets very specific nerves that help reduce pain. The DRG is an easily accessible structure in the spine that plays a key role in the development and management of chronic neuropathic pain. It is a bundle of sensory nerve cell bodies within the epidural space. Each nerve root communicates to the dorsal root ganglion in a way that allows sensory messages from a defined area of the body. Therefore, applying stimulation to the DRG can permit focused therapy to a specific focal area such as an extremity usually affected by CRPS.

Spinal Cord Stimulation (SCS): Spinal cord stimulation (SCS) is a type of neurostimulation of the spinal cord utilized for neuropathic pain or CRPS related pain affecting non-focal areas such as a majority of one or both lower and upper extremities. For complex regional pain syndrome affecting the upper extremities it is the primary mode of long-term interventional treatment.

The ACCURATE study, a pivotal, prospective, multi-center, randomized comparative effectiveness trial, was conducted in 152 subjects diagnosed with complex regional pain syndrome or causalgia in the lower extremities, receiving neurostimulation of the DRG or dorsal column (spinal cord stimulation, SCS).

Read full ACCURATE Study here

References

Birklein F, Riedl B, Sieweke N, Weber M, Neundörfer B (2000) Neurological findings in complex regional pain syndromes—analysis of 145 cases. Acta Neurol Scand 101:262–269
Psychological and behavioral aspects of complex regional pain syndrome management. Bruehl S, Chung OY. Clin J Pain. 2006 Jun;22(5):430-7 PMID: 16772797
Cohen HE, Hall J, Harris N, McCabe CS, Blake DR, Jänig W (2012) Enhanced pain and autonomic responses to ambiguous visual stimuli in chronic Complex Regional Pain Syndrome (CRPS) type I. Eur J Pain 16:182–195
Van Rijn MA, Marinus J, Putter H, Bosselar SR, Moseley GL, van Hilten JJ (2011) Spreading of complex regional pain syndrome: not a random process. J Neural Transm 118:1301–1309
Deer, T. R., Skaribas, I. M., Haider, N., Salmon, J., Kim, C., Nelson, C., Tracy, J., Espinet, A., Lininger, T. E., Tiso, R., Archacki, M. A. and Washburn, S. N. (2013), Effectiveness of Cervical Spinal Cord Stimulation for the Management of Chronic Pain. Neuromodulation: Technology at the Neural Interface. Article first published online: 24 SEP 2013.DOI: 10.1111/ner.12119
16. Deer, T., Skaribas, I., Nelson, C., Tracy, J., Meloy, S., Darnule, A., Salmon, J., Pahapill, P. A., McJunkin, T., Sanapati, M., Lininger, T. E., Russo, M., Haider, N., Kim, C. H., Tiso, R. L., Gomezese, O. F., Braswell, J., Espinet, A., Daudt, D. and Washburn, S. N. (2014), Interim Results From the Partnership for Advancement in Neuromodulation Pain Registry. Neuromodulation: Technology at the Neural Interface. doi: 10.1111/ner.12154
Deer, T., Skaribas, I., McJunkin, T., Nelson, C., Salmon, J., Darnule, A., Braswell, J., Russo, M. and Fernando Gomezese, O. (2016), Results From the Partnership for Advancement in Neuromodulation Registry: A 24-Month Follow-Up. Neuromodulation: Technology at the Neural Interface, 19: 179–187. doi: 10.1111/ner.12378
Ioannis Skaribas MD, Christian Pecora MD, Elena Skaribas RS, Neuromodulation: Technology at the Neural Interface, April 27, 2018 : Single S1 Dorsal Root Ganglia Stimulation for Intractable Complex Regional Pain Syndrome Foot Pain After Lumbar Spine Surgery: A Case Series.
Deer, Pope,..Skaribas et al, Neuromodulation :Technology at the Neural Interface. Volume 22, Issue 1, Review Article. The Neuromodulation Appropriateness Consensus Committee on Best Practices for Dorsal Root Ganglion Stimulation. Deer, Pope,..Skaribas et al, first published: 24 September 2018, https://doi.org/10.1111/ner.12845