08 May Complex Regional Pain Syndrome
Complex regional pain syndrome (CRPS) is an atypical disorder despite the point that it most often occurs after an injury or a surgical procedure.
While that sounds logical – pain after injury or surgery – the illogical part is that the pain is not associated with either the injury or the surgery. Instead, the pain comes from ancillary injury to the peripheral nervous system.
CRPS can also appear without a preceding injury or surgery. In some cases, the preceding “trigger” is as incidental as removing a cast from a broken limb or a slight prick of a needle.
CRPS also has some atypical symptoms. For example, the condition might first appear in one limb – a leg or an arm. Then it might spread. But it can spread from one region to an entirely new region, jumping (or so it would seem) from one arm the other arm, while bypassing the shoulder and the torso altogether.
As such, the condition behaves as if the peripheral nervous system is out of whack. The peripheral nervous system includes all the nerves in the body that are not included in the central nervous system, which is comprised of only the spinal cord and the brain.
There are two basic types of CRPS, separated by the ancillary knowledge of whether or not the specifically injured peripheral nerve can be identified. When doctors cannot identify the injured nerve, the diagnosis is Type 1 or CRPS-I. This was previously known as reflex sympathetic dystrophy syndrome.
When doctors can identify the injured nerve, the diagnosis given is Type 2 or CRPS-II.
Treatments for both conditions are the same, by and large.
CRPS is also identified by other symptoms. These include:
- Chronic pain, lasting more than six months
- Changes in skin color in the affected area – sometimes showing as an inflamed red color, sometimes as a pale, white color
- Temperature changes that could be either the type of heat associated with inflammation or a cold-to-the-touch feeling
- Pain could be felt as a burning sensation or as a tingling sensation
- Abnormal tremors or involuntary jerking motions in the affected limb
- Joint stiffness and lack of coordination in the affected limb
- The tendency to spread from one limb to another
- Changes in growth patterns for nails and hair
- Pain can last from a few weeks to many months or it can turn chronic
- Dystonia (abnormal posture)
- Hyper-sensitivity that can be very painful
While CRPS can recede over time, the condition can be part of a chain reaction that can cause damage to the spinal cord and brain.
This chain reaction starts with the myelin sheath – a layer of fat and protein surrounding some nerve cells – becoming damaged or worn thin. The small fibers of the nerve endings then secrete chemicals that affect blood vessels, causing them to constrict or dilate. This is what causes the inflammation, but it also explains the reaction in which the skin becomes cold to the touch. If blood vessels constrict, the skin becomes oxygen-starved, causing the skin to go pale and even to age prematurely.
Treatment of CRPS usually includes a mix of pharmaceutical, conventional medical and alternative approaches that limit the damage and the lifestyle changes the condition might afflict on someone.
The aim is to reduce the pain and limit the damage before it becomes chronic. While CRPS is more common in women than men and most commonly strikes people in their late 30s to early 50s, it is known to occur in children, although very rarely in children under 5. What is observed, however, is that younger CRPS patients have better treatment outcomes than older patients, which indicates that physical activity is a key treatment component.
Often the first response to CRPS is the same as treating a local injury. This includes options like:
- Heat or cold compresses
- Over-the-counter analgesics
- Physical or occupational therapy
- Exercise or mild activity
- Education or counseling to learn to cope with the pain
There is no specific pill that targets CRPS. But pharmaceutical options include:
- Bisphosphonates, including alendronate or pamidronate
- Nonsteroidal anti-inflammatory drugs (NSAIDs)
- Botulinum toxin injections
- N-methyl-D-aspartate (NMDA) receptor antagonists (ketamine or dextromethorphan)
- Pain relief (analgesic) ointments
Procedural options also exist. These include:
- Nerve block, such as an epidural procedure
- Neuromodulation, such as high-frequency (10 kHz) spinal cord stimulation that can decrease pain by disrupting pain signals before they go to your brain.