Transforaminal Epidural Injection

A transforaminal epidural injection delivers medicine — local anaesthetic with a steroid — into the epidural space at a very specific point: the foramen, the bony tunnel through which a single nerve root leaves the spine. This targeted approach places the medicine right at the affected nerve. It is used for nerve-related pain travelling into the leg or arm (radicular pain, such as sciatica), both to relieve symptoms and, because it is so specific, to help identify which nerve is involved.

Unlike a broader epidural, the transforaminal route aims medicine at one nerve root as it exits through the foramen. The steroid calms inflammation around that irritated nerve, while the local anaesthetic gives more immediate, temporary relief. Because the injection is so precisely targeted, a clear, temporary reduction in the familiar radiating pain also points to that specific nerve as the source — giving the procedure a diagnostic value alongside its treating role. Imaging guidance (usually X-ray screening with contrast, sometimes CT) is used to confirm accurate placement.

The procedure is done in a clean setting with imaging. You typically lie face down; the skin is numbed, and the needle is guided to the edge of the foramen. You may briefly feel a tingle or a reproduction of your usual radiating pain as the needle approaches the nerve, which helps confirm the target. The injection is quick. Afterwards the limb may feel numb or heavy for a few hours, and any steroid benefit builds over the following days. You will be asked to note your pain response and will usually need someone to take you home.

The transforaminal approach is one of the most targeted ways to treat and test a single nerve root. Its precision means it can relieve nerve-related pain while also helping to confirm which level is responsible when a scan shows more than one possibility. That combination makes it a valuable tool, and as always the result is weighed by the specialist alongside symptoms, examination and imaging rather than used on its own.

• —NICE — Low Back Pain and Sciatica in Over 16s (NG59)
• —Faculty of Pain Medicine, Royal College of Anaesthetists — Standards
• —British Association of Spine Surgeons (BASS)

This information is for general patient education and is not a substitute for an individual consultation. Always seek personalised advice from a qualified spinal specialist.