A lumbar epidural steroid injection, or LESI, is used to treat low back pain and nerve pain that travels into the hips, buttocks, or legs. This type of radiating pain is often called sciatica.
The pain is commonly related to a lumbar disc herniation or spinal stenosis. When a disc sprains, tears, or bulges, it can irritate nearby spinal nerves. Sometimes the irritation is chemical, from inflammatory disc material. Other times it is mechanical, from pressure, scar tissue, or nerve tethering.
Why We Do It
The goal of a lumbar epidural is not simply to “numb the back.” The goal is to treat the irritated nerve environment.
In our practice, an epidural can serve both a diagnostic and therapeutic purpose. If numbing medication provides temporary relief, it helps confirm that the targeted nerve area is part of the pain generator. The steroid then works over time to reduce inflammation and calm the sensitized nerve.
How It Works
A lumbar epidural may help in two ways.
First, the fluid used during the injection can help wash inflammatory material away from the nerve and gently separate irritated tissue. This is sometimes described as a hydrodissection effect.
Second, the corticosteroid helps reduce inflammation around the nerve and may soften irritated scar tissue. In patients with dense adhesions or prior spine surgery, additional medication may sometimes be used to help address scar tissue.
What to Expect
The procedure is performed using imaging guidance, typically fluoroscopy, so the medication can be placed precisely. Patients usually lie on their stomach while the skin is cleaned and numbed.
Sedation may be available for comfort. If sedation is used, patients need to follow fasting instructions and have someone take them home.
During the injection, it is normal to feel pressure in the back or a sensation traveling down the leg. This can be uncomfortable, but it also helps confirm that the medication is reaching the intended area.
Benefits and Timeline
Some patients feel temporary relief right away from the local anesthetic. The steroid effect usually takes longer and may build over several days to two weeks.
Relief varies from patient to patient. A successful injection may reduce pain enough to allow better movement, better sleep, and more productive rehabilitation. The long-term goal is not only symptom relief, but also helping the patient address the mechanics that may have irritated the nerve in the first place.
Our Approach at MPM
At Manhattan Pain Medicine, we use lumbar epidural steroid injections as part of a diagnosis-first plan, helping patients understand whether sciatica or low back nerve pain is coming from disc irritation, stenosis, scar tissue, or a more layered spine pattern.
