Nerve Root Blocks

A nerve root block is an injection into the sheath surrounding a nerve root in the spine to decrease your pain temporarily and to define it more precisely. The exam uses therapeutic steroid and local anesthetic (numbing medication) to decrease pain and inflammation. Pain relief from the procedure varies from minimal to long-term, depending on the specific symptoms.

You must have symptoms present for this procedure to be effective. If you are not experiencing symptoms prior to your procedure, please cancel your appointment and reschedule the exam once your symptoms have returned.

Procedure preparation

A technologist or nurse will contact you 24-48 hours prior to your appointment to review medications you are currently taking, especially pain medications and blood thinners, discuss known allergies and your medical history, as well as answer your questions.

Contact your doctor before you stop taking any medication.

Please bring previous imaging study results (MRI, CT, x-rays) such as films, reports, or CD-ROMs, if available.

You will need a driver for your appointment. If you are unable to drive or arrange transportation, call us for assistance.

Please notify a member of our staff if you are nursing or if there is a chance you may be pregnant.

What to expect during the procedure

You will remain awake throughout the procedure.

A radiologist will use a thin needle to place anesthetic and steroid (anti-inflammatory medication) into the nerve sheath. (There may be some discomfort from the needle, but, for most people, this is minor.)

The radiologist checks the needle position using x-ray-guidance (fluoroscopy).

Contrast material is placed into the nerve sheath to document the needle position and x-rays are taken.

During the injection, you may feel pressure or pain. The radiologist will want to know how this discomfort compares to your usual pain symptoms.

What to expect after the procedure

Initially, you may experience numbness and/or relief from your symptoms for up to six hours after the injection.

When the anesthetic wears off, your usual symptoms may return. The steroids usually require 2-3 days to provide pain relief.

If there is no change in your pain symptoms after a week, your doctor may want to investigate other possible sources for your pain.

Potential side effects

Steroid medications may cause facial flushing, occasional low-grade fevers, hiccups, insomnia, headaches, water retention, increased appetite, increased heart rate, and abdominal cramping or bloating.

These side effects occur in only about 5% of patients and commonly disappear within 1-3 days after the injection.