Your body has special nerves that control your blood vessels. Some of these are known as sympathetic nerves. These nerves can be anesthetized to change the blood low to a limb. Additionally, sometimes these nerves are involved in painful conditions traditionally known as reflex sympathetic dystrophy (RSD) or known today as complex regional pain syndrome (CRPS). The sympathetic nerves to the leg are best blocked in the low back

Nerves have a "home" known as a ganglion where the cell body resides. The ganglion is where these blocks are performed. For a lumbar sympathetic block, you will lie on your back on an X-ray table. Normally you will be sedated for the procedure.

Utilizing X-ray pictures, Dr. Harries will position a needle in the area of the nerves and inject some local anesthetic. The location of the lumbar sympathetic nerves is indicated by the orange line on the image. It the block works, then your foot will warm up and, depending upon the source of your pain, your pain may improve. When utilized for CRPS (RSD) lumbar sympathetic blocks are used as a way of getting you to work with physical \ occupational therapy to desensitize your leg or foot. The commonest risk associated with this procedure is of feeling faint or developing a low blood pressure.