CRPS stands for Complex Regional Pain Syndrome. There are two subtypes of CRPS named CRPS I and CRPS II with the difference being evidence of actual nerve damage in CRPS II. The terminology of CRPS is relatively new. It came into existence in 1993. Prior to that, CRPS I was named Reflex Sympathetic Dystrophy and CRPS II was termed Causalgia. While these older names are still used today, CRPS has become more commonplace.
There are several signs and symptoms for CRPS. They include inflammation, extreme pain (beyond what would be considered a typical pain response), burning, standing, grinding, skin color changes, nail changes, hair changes, muscle loss, and changes in sweating. People with this ailment can also have pain from stimuli that are traditionally non-painful, think of water hitting your leg in the shower, this isn’t usually painful but it can be with CRPS. The term for this pain response is allodynia.
There really isn’t any specific cause for CRPS. Typically, the inciting event is some form of trauma, this could be a car wreck, a sports injury, or a medical procedure or surgery. The pain can be rather debilitating and is also progressive, meaning it can get worse over time. Luckily, the prevalence of CRPS is only about 15 people per 100,000.
How do we diagnose CRPS. There are specific criteria that are used to diagnose CRPS. This is called the Budapest criteria. The picture below explains how this works. In general, you have to have pain that is disproportionate to the inciting event, no other diagnosis can better explain the symptoms, and then 1 sign in to or more of the categories listed in the image and 1 symptom in 3 or more of the listed categories.
Treatments are similar to what we use with neuropathy but there are additional considerations. Medications to help with the nerve pain can be helpful but may not be enough to fully control the pain. These patients will frequently take opioids for breakthrough pain. Desensitization therapy is a key to treatment. The entials having a therapist touch the affected area so that it can get used to feeling non-painful stimuli. Desensitization is often done after a nerve block (to numb the area) so that the patient can tolerate it. The nerve blocks completed are the sympathetic blocks that we have talked about earlier.
There is an additional method for pain relief in these patients that is an implantable device about the size of a pacemaker. This is a spinal cord stimulator device that can be used to treat a variety of pains, but does really well when used to treat CRPS. We will discuss spinal cord stimulation at greater length in another post.
All in all, CRPS is a painful disease that isn’t easily treated. Luckily, it also isn’t that common. Often treatment is multifactorial in order to obtain the success that the patient is desperately looking for.