COMPLEX REGIONAL PAIN SYNDROME
This complication can occasionally follow surgery or injury to the limbs. The nerves within the affected limb appear to demonstrate an exaggerated response to the injury, that is to say that the limb is often more sensitive, swollen and painful than would be expected, in the short term. In the longer term the limb can become very stiff.
CRPS has previously been referred to by various names including Reflex Sympathetic Dystrophy, Sudek’s Atrophy and Shoulder-hand syndrome. The term Complex Regional Pain syndrome however has been used since 1991.
There are two types. The first follows an injury or surgery and the second as a result of injury to a nerve.
WHAT CAUSES IT?
The cause for this is unclear but it often follows an injury that can be trivial. There are two schools of thought. The first suggesting that this arises from an abnormal stimulation of the nerves in the limb. The second suggests that the brain drives the process, sending abnormal signals to the nerves in the limb.
This condition is seen more often in women and those above the age of 30 years. It can however, also occur at the extremes of age. We encounter this problem most often in patients who have had wrist fractures, particularly those who may have had a manipulation and had the fracture treated in plaster.
WHAT ARE THE SIGNS AND SYMPTOMS?
The symptoms can vary both in the severity and the distribution. The common features however include: pain out of proportion to the injury or treatment, pain which extends beyond the injured or operated area, changes in skin colour and temperature compared to the opposite limb, swelling of the limb and stiffness.
HOW IS IT DIAGNOSED?
There is no blood test or scan that will identify this problem. The diagnosis is often made based on the features described above. You may however have an x-ray as this condition can lead to the thinning of the bones in the hand (osteopenia).
HOW IS IT TREATED?
There is no cure for the condition but the treatment focuses on treating the individual symptoms. The most important part of the treatment is prevention followed by the early recognition of the features. Recognising the problem early and commencing treatment increases the chance of a favourable outcome.
The condition can be avoided to some extent by ensuring that plaster casts are not applied too tightly and that all joints that have not been immobilised are moved straight away. There is also evidence that taking vitamin C tablets following a wrist fracture for up to 6 weeks following the injury can reduce the risk of CRPS. Once the condition is established the mainstay of the treatment is hand therapy. This is often supported by pain relieving medication. Injections around the nerve centres that drive the process can occasionally be helpful. Surgery has a small role to play in the treatment. This is used for the repair of nerves if injured or for manipulation of joints that have become stiff.
WHAT IS THE OUTLOOK?
With early diagnosis and treatment the duration of the symptoms can be shortened. It can however be many months before a measurable improvement in the symptoms is seen. Unfortunately most patients do end up with some long-term impairment in the form of ongoing pain or residual stiffness.