Epidural Steroid Injection (ESI)
- Interlaminar ESI. This method accesses the epidural space from the middle of the back under X-Ray guidance. After numbing medicine is applied, a small needle is inserted under the skin towards the space between two vertebrae. When the needle tip is in the correct place, we inject contrast dye to confirm a good spread of the medication. Next, local anesthetic and steroid medication is injected into the epidural space to reduce inflammation and pain. This medication is delivered to multiple nerve roots on both the right and left sides of the midline at the same time.
- Transforaminal ESI. This method accesses the epidural space from the left, right, or both sides in the middle of the back. We perform this injection when pain is localized along the pathway of a single nerve root, or in patients who have undergone a previous spine surgery. After giving numbing medicine, we use X-Ray to place our needle towards the side of the vertebrae, approaching the location where the nerve root exits the spine. Then, we use contrast dye to confirm that the needle is next to the nerve that is causing pain. Next, we inject numbing medicine and steroid to reduce the inflammation and pain from this nerve.
What to expect after an Epidural Steroid Injection
The epidural injection contains a mixture of local anesthetic (usually lidocaine) and a steroid medication.
The local anesthetic may provide partial pain relief within 10 to 15 minutes after the completion of the procedure but may last for a few hours only. Mild numbness or heaviness of an extremity can also be experienced, but almost all patients are able to stand and walk out without assistance.
The steroid will usually start working within 24 to 72 hours. The pain relief and improvement in function may last for days, weeks, or even several months after a single injection or a series of injections.
Although uncommon, some patients may experience a temporary increase in their usual pain for a few days following the procedure.