A herniated disc occurs when the soft, jelly-like inner portion of a spinal disc pushes out through a tear in its tougher outer layer. This displacement can compress or chemically irritate nearby nerve roots, leading to localized discomfort or radiating pain, commonly known as sciatica. Sciatica causes pain, tingling, numbness, or weakness that travels from the lower back down into the leg and sometimes the foot. Corticosteroids are used as a non-surgical approach to manage such pain by targeting the inflammation around the affected nerves.
How Steroids Reduce Herniated Disc Pain
The pain associated with a herniated disc is not due to physical pressure on the nerve. It results from inflammation and chemical irritation of the nerve root caused by substances released from the disc material. These chemicals contribute to severe pain by irritating nerve roots.
Corticosteroids are anti-inflammatory agents that reduce the production of inflammatory chemicals. By calming the inflammation and swelling around the irritated nerve root, steroids alleviate pressure and diminish pain signals. These medications do not physically heal the herniated disc or cause it to shrink. Their action is to provide pain relief and reduce inflammation, which can create a window of opportunity for natural healing processes or for physical therapy to become more effective.
Types of Steroid Administration
Steroids for herniated disc pain can be administered in different ways. Oral steroids are taken by mouth in pill form. These medications provide a systemic, or whole-body, anti-inflammatory effect, reducing inflammation throughout the body. Oral steroids are prescribed for a short course to manage acute pain flare-ups.
Epidural Steroid Injections (ESIs) offer a more targeted approach, delivering the corticosteroid directly into the epidural space. This space surrounds the spinal cord. By injecting the medication here, it can reach the inflamed nerve root more directly than oral medications. Different techniques for ESIs are chosen based on the specific location of the nerve irritation.
The Epidural Injection Procedure
Receiving an epidural steroid injection involves a precise process. Patients lie on their stomach, and a local anesthetic is applied to numb the skin at the injection site. The physician uses fluoroscopy, live X-ray imaging, to guide the needle to the correct position within the epidural space.
Once the epidural needle is in place, a small amount of contrast dye is injected. This dye appears on the fluoroscopy screen, confirming that the needle tip is correctly positioned in the epidural space. After confirmation, the corticosteroid medication is slowly injected. The entire procedure takes a short time, followed by a brief observation period before the patient can go home.
Potential Side Effects and Limitations
Both oral steroids and epidural steroid injections carry potential side effects and limitations. Oral steroids can cause systemic effects like insomnia, mood changes, increased appetite, and elevated blood sugar levels. Other common effects include fluid retention, stomach upset, and thinning of the skin with prolonged use.
Epidural steroid injections have more localized side effects, though systemic effects like facial flushing, temporary pain increase at the injection site, or headache can occur. While rare, more serious risks associated with injections include infection, bleeding, or nerve damage. The relief provided by these injections is temporary, lasting from a few weeks to several months, and results vary significantly among individuals. Healthcare providers limit the number of epidural steroid injections a person can receive to two to four per year, to minimize risks such as weakening of spinal bones or surrounding muscles.