Diagnostic Tests for Complex Regional Pain Syndrome

The diagnosis of Complex Regional Pain Syndrome is based on medical history, physical symptoms and ruling out other medical causes. Other disorders or vitamin deficiencies can occur with CRPS. There are no diagnostic tests which point to CRPS specifically. These are the most common diagnostic tests for Complex Regional Pain Syndrome.

Diagnostic Test One: Magnetic Resonance Imaging-MRI

There is no preparation needed before this diagnostic test unless your doctor has special instructions for you. Do not wear clothing with zippers or snaps. Sweat pants and a plain t-shirt with no decoration is the ideal clothing to wear. If you have a pacemaker or other device, you will not be able to have an MRI.

When a doctor suspects CRPS in a patient who might have joint, muscle or tissue damage, they may order an MRI. It is also useful for finding any abnormalities in the spine that could explain pain or other symptoms, such as numbness. An MRI will not show evidence of CRPS.

Diagnostic Test Two: X-Rays

X-rays are taken when there are suspected fractures of the bone. This will not help diagnose CRPS. X-rays can show if there is osteopenia or osteoporosis in the CRPS limb.

Diagnostic Test Three: Electromyography/Nerve Conduction Velocity-EMG/NCV

An EMG/NCV is done if the doctor suspects nerve damage or nerve entrapment. A neurologist is the doctor who administers this test. There is no preparation needed for this diagnostic test. If the limb is cold, the doctor may place a heat pack on it. A low skin temperature will slow nerve conduction giving an inaccurate result.

The EMG part of the diagnostic test involves inserting a very fine needle into the muscle. This tests the electrical activity within the muscle. It may be extremely painful for some people with CRPS, while others have only mild discomfort.

During the NCV portion of the test, patch electrodes are placed on the skin. The patches are similar to ones used to monitor heart rhythm in the hospital. The neurologist then stimulates the nerves with a mild electrical impulse. Many of those with suspected CRPS will have an EMG/NCV. This test will not show CRPS in a limb.

Diagnostic Test Four: Bone Scan

The type of bone scan most often done when CRPS is suspected is the 3-Phase bone scan. There is no preparation before having this diagnostic test. You can eat, drink and take your medications as normal.

Before doing the scan, a radioactive tracer is injected into a vein in your arm. The initial scan is done immediately after injection of the tracer. The next scan will be done approximately 20 minutes after the injection. The final scan will take place two to four hours later.

You will be allowed to leave before the last scan is taken and given a time to return. You are encourged to drink lots of fluid. Before going back in, you will be asked to completely empty your bladder. This flushes out any build up of tracer which could obscure the pelvic area.

A bone scan may show CRPS if it is done within the first four months after symptoms begin. Bone scans can show osteoporosis which is one of the changes CRPS has on bone. Each person is different and may not develop osteoporosis at all. Many people with CRPS have normal bone scans. This does not mean the person does not have CRPS.

These are not the only diagnostic tests for Complex Regional Pain Syndrome. They are the four most common diagnostic tests for people with CRPS. The doctor who orders any diagnostic tests will select the ones he or she feels is necessary.

Resources

http://www.emedicinehealth.com/magnetic_resonance_imaging_mri/article_em.htm

http://www.emedicinehealth.com/electromyography_emg/article_em.htm

http://www.emedicinehealth.com/bone_mineral_density_tests/article_em.htm

http://www.medscape.com/medline/abstract/2738340