Transforaminal Epidural Steroid Injection or Selective Nerve Root Block
What is the epidural space and why is a selective epidural helpful?
The membrane that covers the spinal cord and nerve roots in the spine is called the dura membrane. The space surrounding the dura is the epidural space. Nerves travel through the epidural space before they form the nerves that travel down the arms, along the ribs and into the legs. The nerves leave the spine from small bony openings called foramen. Inflammation of these nerve roots may cause pain in the arms, chest or legs. These nerve roots may become inflamed and painful due to irritation, for example, from a damaged disc or a bony spur.
Selective epidural injection (transforaminal epidural/selective nerve root block) places anti-inflammatory medicine over the root and into the epidural space to decrease inflammation of the nerve roots, therefore reducing the pain. It may provide permanent relief or provide a period of pain relief for several months while the injury/cause of pain is healing.
What happens during the procedure?
An IV may or may not be started at the physician’s discretion. The patient is placed on their stomach on the procedure table and positioned in such a way that the physician can best visualize the bony openings in the spine where the nerve roots exit the spine using x-ray guidance. The skin in the appropriate area is scrubbed using antibacterial soap. Next, the physician numbs a small area of skin with numbing medicine. This medicine stings for several seconds. After the numbing medicine has been given time to be effective, the physician directs a very small needle using x-ray guidance above the nerve root as it leaves the foreman. A small amount of contrast (dye) is injected to insure proper needle positioning. Then, a small mixture of numbing medicine (local anesthetic) and anti-inflammatory (steroid) is injected.
What happens after the procedure?
There are no restrictions to food or liquid intake or to activity level unless specified by the physician. A follow-up appointment will be made for a repeat block if indicated. These injections are usually done in a series of three, about one month apart. The back or legs may feel weak or numb for a few hours. This does not always happen, but is an expected possible temporary reaction to the procedure. Patients may return to their normal activities on the day of the procedure. Driving is discouraged on the day of the procedure.