An Overview of the Three Different Types of Epidurals for Pain Management

spinal stenosis

Epidural cortisone injections represent an excellent treatment option for pain management patients suffering from spinal nerve irritation, which is also termed radiculitis.

The injections work well for leg pain coming from herniated discs along with radiculitis coming from the various different types of spinal stenosis, including foraminal, central, and lateral stenosis. Also, epidural injections work well for radiculitis coming from disc problems. Can epidurals work well for back pain? Yes they can, but mostly they are for leg pain problems.

Cortisone spinal injections are really meant to get patients "over the hump". Cortisone puts "water on the fire" so to speak, allowing patients into rehab more comfortably and hopefully work and play with their kids and socialize. The cortisone doesn't fix anything but they can temporarily do well with pain control.

Until we come up with something better, predominantly cortisone is injected. How well does it work?

It works by neural membrane stabilization along with blocking phospholipase A2 activity, and inhibiting neural peptide synthesis.

Local anesthetics by themselves have been shown to produce a prolonged dampening effect of the dorsal horn and c-fiber activity. This may provide excellent pain relief by themselves without cortisone.

Fluoroscopic guidance is the current standard of care with epidural cortisone injections. Multiple studies have shown upwards of a 35% improper placement outside the epidural space without fluoroscopy.

Here are the different types of injections along with some facts on each:

1. Caudal epidural injections - Indications include when it's tough to get to the other approaches with intra-laminar or transforaminal approaches. Usually administered in post-surgical patients when transforaminal technique is not possible. There are also indications for a caudal injections with pelvic pain. These injections are least technically demanding. Need a larger volume to hit the targets, usually 10 milliliters are needed to reach L5-S1 and over 20 milliliters are need to reach above L4-5. The miss-rate without fluoroscopy for caudal epidurals is 40% according to the literature.


2. Interlaminar Epidural Cortisone Injections - This type of injection allows for administration of medication to higher lumbar levels. One of the biggest downsides to interlaminar variety is that it has the highest incidence of dural tears which may lead to headaches (5%). Advantages include being fairly technically simple. It does require physicians being familiar with the "loss of resistance" technique. It also allows for delivery of medication to areas higher in the spine than the caudal route. Frequently these injections are performed blind, without fluoroscopy, and this is a disservice to the patient. Research shows 30% misplacement without it.


3. Transforaminal ESI - The indication for TESI is for radicular pain, with the rationale being delivering the drug in maximum concentration and closer to the site of pathology. There are multiple studies demonstrating the efficacy. Disadvantages include very rare events of bad things happening. These injections are technically the most demanding, and there is a slight risk of direct nerve trauma. A study by Weiner in 1997 showed that these injections may be surgery sparing. There was a 46% rate of achieving complete pain relief. Multiple studies have shown that 2/3 of patients have been able to avoid surgery with these interventions. A 2010 study by Bogduk et al was a prospective randomized blinded study looking at transforaminal epidurals with cortisone plus anesthetic, versus anesthetic alone versus saline in the epidural space. The study also looked at intramuscular injections without epidural injection. Well over 50% of patients received over 50% pain relief for the epidural injection with cortisone and lidocaine. Twenty five percent of the patients ended up pain free completely. The other groups achieved between 7% and 21% pain relief, so much less.