Reflex Sympathetic Dystrophy (RSD), also known as complex regional pain syndrome(CRPS), is a chronic condition which often occurs at the site of an injury and is characterized by severe burning pain in a limb and often associated with extreme sensitivity to touch, tissue swelling, changes in the bone and skin and excessive sweating.
Symptoms of RSD
The symptoms of RSD usually occur near the site of an injury you have suffered in the past, either major or minor. All patients with RSD suffer from pain, usually burning and constant in nature. Other symptoms which you may or may not have include swelling, changes in the appearance of the nails and skin, increased sweating, joint tenderness or stiffness and movement problems. One visible sign of RSD that may appear near the site of injury is warm, shiny skin that later becomes cool and bluish.
The one symptom that all patients with RSD have is pain that is out of proportion to the severity of the injury. It often gets worse, rather than better, over time and can last months and even years .It is often described as a burning or aching pain which may at first be localized to the site of injury or the area covered by an injured nerve but spreads over time, often involving the entire limb. It can sometimes even involve the opposite limb. Pain is continuous and may be made worse by emotional stress. Moving or touching the limb is often intolerable, and eventually the joints become stiff from disuse.
Cause of RSD
Though the cause of RSD is unknown, it is thought to be the result of damaged nerves of the sympathetic nervous system. These damaged nerves send inappropriate signals to the brain, interfering with normal information about sensations, temperature and blood flow. The end result of all of this is inappropriately severe pain for the level of injury present. Since RSD often starts after trauma or injury to an extremity, conditions that can bring about RSD include sprains and fractures, surgery, damage to blood vessels or nerves, or brain lesions. "Injury" can be something as minor as having an IV started, and sometimes no apparent injury can be found. Our best estimates are that from two to five per cent of patients with a nerve injury will develop RSD.
There is no single test for diagnosing RSD. Instead diagnosis is made through observation of the patient’s signs and symptoms followed by certain tests which include specific nerve blocks of the sympathetic nervous system. When diagnosed and treated within the first 3 to 6 months there is the highest possibility of cure and treatment is most effective. Since you have been referred to me for consideration of a nerve block, your primary doctor has obviously thought that RSD may be your problem. Unfortunately though, RSD is so poorly understood and so easy to misdiagnose that treatment often starts later than what would have been preferred in hindsight.
Though there is often no cure for RSD, treatment in the first 3 to 6 months is, as stated above, reasonably effective. It usually involves a multi-pronged approach including nerve blocks, medication (such as low dose antidepressants or anticonvulsants), physical therapy, psychotherapy and even electrical stimulation. More invasive treatments are often needed in the later stages of RSD, and in some cases surgical or chemical sympathectomy (interruption of the affected portion of the sympathetic nervous system) is necessary to relieve pain. This involves cutting or destroying the nerves, and this will often stop the pain almost instantly. It may also destroy other sensations as well, and unfortunately is no guarantee the pain will not return at some later date. While many physicians once thought that RSD was caused by emotional disturbances, they now agree that the emotional problems that are often seen arise from the physical problems caused by RSD. Doctors now believe that medical treatment usually remedies the emotional problems, but that psychological therapy is still an important part of treatment for most patients, if for no other reason than it helps them cope with the changes the disease can bring.
Sympathetic Nerve Blocks
If you are reading this, it is probably because your doctor has sent you to me to evaluate whether you are a candidate for a sympathetic nerve block. If your pain is mainly in an arm you will undergo a series of either stellate ganglion blocks or IV regional sympathetic blocks. In a stellate ganglion block, local anesthetic is injected close to the sympathetic nerves in the neck through a needle which I will insert just to the side of your voice box. In an IV regional sympathetic block, sympathetic nerve blocking drugs are injected directly into a vein in the affected arm. A tourniquet is placed on the arm to keep the drugs in the arm for 30 minutes or so before being released. Which one is best for you is a decision based on a number of factors, but I perform stellate ganglion blocks much more often.
If your pain is mainly in a leg I will perform a lumber sympathetic block. Just as in the stellate ganglion block, a needle is inserted close to the sympathetic nerves and local anesthetic is injected. The sympathetic nerves to the leg can be blocked just to the side of the spine in the lower back. Because these nerves are quite deep and the needle is difficult to reliably insert "by feel," I do this block in the operating room using x-ray guidance to assure proper needle location.
The side effects and complications of these various blocks vary, so I will go over these individually with you, but for all of them the chance of a major problem is relatively low. As far as positioning is concerned, you will lay on your back if I am blocking your arm and on your belly if I am blocking your leg. Regardless of the block used, if necessary you may receive a short-acting sedative to make the block more tolerable (which is why you are asked not to eat or drink anything for four hours before the block.) Usually a series of blocks will be necessary before the nerves that have been firing inappropriately stop firing for good. As the series of blocks continues, though, I look for you to get longer and longer pain relief with each block until at some point the pain does not return and repeat blocks are therefore no longer necessary.
All of your physicians have as a goal minimizing the amount of pain that you experience, and a series of sympathetic nerve blocks can be one part of the treatment that helps you attain that goal.
Please click on the link below to be redirected to the website spine-health.com to see a video animation of a lumbar sympathetic block