There is no easy, risk-free, accurate test. X-rays classically show a patchy osteoporosis, but pain and disuse following surgery can also produce this picture. A sympathetic block comes closest to being the definitive test for the condition: anesthetizing the lumbar sympathetic chain provides significant pain relief for the duration of the block - but only in patients with RSD. Failure to obtain pain relief with such a block suggests that the patient does not have reflex sympathetic dystrophy. BUT because some sympathetic fibers can bypass the sympathetic chain, failure of a block still does not automatically rule out RSD. Sympathetic blocks have their downsides. They are costly, invasive, and for the test to be meaningful care must be taken not to inadvertently anesthetize the somatic nerves. Therefore the decision to perform or not to perform a block can be difficult when the patient does not have all the classic RSD symptoms. Consultation with a Pain Service can be useful.

Prior to the advent of sympathetic blocks, technetium bone scanning was favored. Unfortunately technetium bone scans are neither sensitive nor specific enough to provide a definitive diagnosis.

Since a hot scan leads the doctor to order a sympathetic block, and since a cold scan in a patient suspected of having RSD also leads the doctor to order a sympathetic block (see above), scanning is in my opinion rarely warranted.

*Note: in my experience Anesthesiologists from Pain Services not uncommonly turn patients down for sympathetic blocks on the grounds that the patients have insufficient findings of RSD to warrant the risks and expense of such testing.

If the patient is found to have reflex sympathetic dystrophy, a multidisciplinary team is often assembled, including an orthopedist, anesthesiologist, physical therapist and even on occasion a psychiatrist to address the depression which can be associated with reflex sympathetic dystrophy. Treatment often consists of chemically blocking the sympathetic nerves. This is done via injections in the sympathetic chain just lateral to the spine or, on occasion, via oral medication. Many injections can be required.