NERVEmber Pain: CRPS And The Quest For Better Treatments

Whenever the nervous system is affected or involved in any way, things get complicated. So, we at FindMeCure are starting off NERVEmber with a post about quite the obscure condition that otherwise doesn’t get much attention in comparison to its more talked about relatives in the family of nervous system diseases: MC, Alzheimer’s, Epilepsy, Parkinson’s…

Yes, that’s right, we’ll be talking about CRPS today. Since it’s nerve pain awareness month, paying attention to and raising awareness about a condition specifically named after the pain it causes seems like the way to go.

And we already see some hands raised, “What even is CRPS?”, you ask. Short for complex regional pain syndrome, CRPS is a chronic condition of the peripheral and central nervous system.

What is CRPS?

CRPS typically manifests after an injury to the arm or the leg and what we need to understand about it is that CRPS is an exaggerated reaction – the pain experienced is disproportionate to the sustained injury. According to Burning Nights – an organization that aims at raising awareness of CRPS and supporting people living with it and their families, this condition affects an estimated 5% of all injuries but in some cases, it can progress significantly and cause bone and joint damage, skin change, abnormal sensitivity to touch and other debilitating symptoms. It can even spread in other areas of the body, unrelated to the injury that initially triggered it. 

There are two types of CRPS – Type I occurs after an injury that, however, did not damage a nerve, while Type II is directly linked to a damaged nerve. Another classification refers to whether the CRPS is in the acute or chronic stage.

That’s the so-called Hot/Cold CRPS line. When medical professionals use the term ‘Hot’ or ‘Warm’ or even sometimes ‘Red’ in regards to CRPS they mean that the affected area shows signs of inflammation and its temperature is higher than that of the rest of the patient’s body. This is also the acute phase of the condition.

Then there’s the Intermediate CRPS – the affected area is neither warm nor cold. And then, in the chronic phase of the condition, the term ‘Cold’ or ‘Blue’ is used to describe it. Those with Cold or chronic CRPS have a greater risk of dystonia – a disorder characterized by tremor-like movements or unnatural fixed postures.      

What types of therapies and treatments are there?

There is currently no medication approved by the Food and Drug Administration for CRPS specifically. So, to treat the pain and inflammation medical professionals resolve to other established methods.

While there’s ongoing research, which we’ll talk about in the next section, symptoms now are treated mainly with pain medication, anti-inflammatory drugs, physical therapy, and psychotherapy.

Why the latter, you ask. Well, CRPS is associated with high levels of anxiety and depression – both conditions that in turn heighten the experience of pain. Which causes even more anxiety and so the vicious cycle continues.

There are therapies that are more or less ‘out there’, some of which are kind of controversial, others – deemed ‘alternative’. Sympathetic nerve blocks, for example, are injected next to the spine. They block the activity of the sympathetic nerves as the name suggests and are linked to short-term pain relief.

However, people who benefit from them sometimes undergo a sympathectomy – a surgery to remove or destroy some of the nerves that carry the pain. It’s not a preferable solution, however, and some specialists advise against it.

Then, there are some invasive and some non-invasive forms of neural stimulation that work wonders in certain cases. Spinal cord stimulation, for example, leans more on the invasive side since it places electrodes near the spinal cord for a test period. If the ‘test period’ ends with good results, the electrodes can be implanted permanently. However, one-fourth of patients that undergo the procedure experience technical issues later on… so maybe some improvements are in order.

Other forms of stimulation show good results too, but out of the non-invasive options, one seems to generate more interest in recent years. TMS or rTMS stands for (repetitive) Transcranial magnetic stimulation and it’s mostly used to treat depression when all other treatments are ineffective. TMS uses magnetic fields to stimulate certain parts of the brain and it’s completely painless and so far side effects are rare.

What about other treatments? Alternative, experimental, under investigation…

As far as alternative treatments go, acupuncture has a long history of being used to treat pain and other pain-related conditions. Biofeedback, another form of alternative medicine, aims at increasing awareness in patients about their physiological functions and eventually allowing them to control some of these functions at will – like pain perception. Patients can also supplement their treatment with chiropractic therapy.

Now, there’s more to CRPS treatment than relaxation techniques and acupuncture. Some drugs and therapies under investigation already show promising results. One of these drugs in clinical trials for CRPS is neridronic acid which belongs to a class of drugs used to prevent the loss of bone density and was previously used exactly for that until a 2013 trial suggested it could be effective in treating CRPS too.

A more adventurous approach still in phase I and II includes the use of adipose tissue. To put it simply, the trial investigates a form of cell therapy that aims at regeneration of damaged tissues by introducing cells extracted from adipose tissue. So far, this kind of therapy has shown potential to decrease inflammation on top of promoting regeneration. This recent advancement, however, is still in the early stages of development and it’s not going to be readily available anytime soon.

Another method of interest when it comes to the treatment of CRPS is Intravenous immunoglobulin (IVIG), that has been researched for its potential to reduce the intensity of pain in a small trial in Britain. The mixture of antibodies used for the treatment of a wide array of conditions proved to decrease the pain of the 13 participants in the trial who otherwise did not respond to other treatments.

However, a more recent and larger scale study concludes that the results of IVIG treatment don’t show significant enough improvement, stating that “Low-dose immunoglobulin treatment for 6 weeks was not effective in relieving pain in patients with moderate to severe CRPS of 1 to 5 years’ duration.”

Graded motor imagery is another possibility for the treatment of chronic pain conditions. It’s based on the concept of neuroplasticity – the notion that complex structures in the brain can be altered by our activities – and it consists of a sort of ‘exercises’ for the brain. According to NCBI, Graded motor imagery shows better results at decreasing pain compared to standard physiotherapy, however, more research is needed to draw a conclusion.

CRPS remains an insufficiently explored condition and we’re a long way from finding better treatments and methods for managing chronic pain. Nevertheless, persistent efforts from recent years can add up to a series of advancements and unlock new opportunities for treating pain and inflammation. We just have to persevere.