Epidural (or peridural) infiltrations with cortisone are a common therapy for many types of lumbalgia and pain of the legs caused by inflammation of the sciatic nerve or a disc hernia (herniated disc).
The aim of the injections is to relieve the pain. Sometimes a few injections are sufficient for pain relief.
However, this treatment should be done in conjunction with a comprehensive rehabilitation program to maintain long-term improvement and treat the cause of the back pain.
Most doctors agree that while the effects of injections are usually temporary, they can reduce symptoms over a period of one week to a year.
Epidural infiltrations can be very helpful for a patient during an acute episode of pain in the back or legs. In addition, a cortisone injection can sufficiently relieve the pain so that the patient can perform a program of stretching and rehabilitation exercises. If the initial injection is effective in a patient, up to three infiltrations per year can occur.
In addition to the lower part of the back (lumbar region), epidural injections with cortisone are also performed to relieve cervical pain (in the region of the neck) and chest pain (dorsal).
Effectiveness of epidural infiltrations
While many studies document short-term benefits from epidural steroid injection, the claims for longer-term efficacy are less convincing. In fact, the results of lumbar epidural injections of steroids continue to be a controversial issue.
For example, many studies do not use fluoroscopy to visualize the correct positioning of the drug. And this despite the fact that fluoroscopic guidance is nowadays a routine procedure.
Nevertheless, most study results show that more than 50% of patients with epidural steroid injections experience pain relief.
The scientific studies also indicate that the therapy is more effective when it is carried out by professionals with many years of experience, who always use fluoroscopy for positioning.
Potential benefits of injections
The epidural injections of cortisone bring the drug injected paravertebrally directly (or very closely) to the source of pain.
In contrast, the oral painkillers and corticosteroids have a different mode of action, are less concentrated and can cause unacceptable side effects. In addition, since most pain is caused by chemical inflammation, an epidural injection of cortisone can help control local inflammation and pain.
The epidural space is a narrow space within the spine that surrounds the dural sac (dura mater) and is filled with adipose tissue (fat) and small blood vessels.
The dural sac surrounds the spinal cord, nerve roots and cerebrospinal fluid (the cerebrospinal fluid used to supply the central nervous system).
A solution containing cortisone and a local anesthetic (lidocaine or bupivacaine) and/or saline solution is usually used.
Most often, cortisone is injected as an anti-inflammatory agent. The inflammation is present in many lumbar ailments and reducing the inflammation helps in eliminating the pain.
Triamcinolone acetonide, dexamethasone and methylprednisolone are commonly used steroids.
Lidocaine is a fast-acting local anesthetic for temporary pain relief.
Bupivacaine is a more permanent medication that is used every now and then. Although the injection is mainly used for pain relief, saline is used to dilute the local anesthetic or as a “wash” that serves to dilute the chemical or immunological substances that maintain the inflammation.
What are the indications for lumbar epidural injection?
Various general conditions leading to severe acute or chronic lumbalgia or pain in the legs (sciatica) due to inflammation of the sciatic nerve can be cured by local cortisone injections.
These diseases include:
- Herniated disc in the lumbar spine (lumbar disc hernia), in which the disc nucleus protrudes through the outer fibrocartilage ring (anulus) into the spinal canal and presses there on the spinal cord and nerve roots.
The disc hernia can cause sciatica or lumbocruralgia.
- Degenerative disc disease, where the collapse of the disc can interfere with the nerves of the lower back.
- Lumbar spinal canal stenosis, a narrowing of the spinal canal that literally squeezes the nerves and spinal cord, causing significant pain.
- Lumbar vertebral collapse, which means the fracture of at least one vertebra, which loses height and changes shape.
- Cysts that occur in the facet joints and can press on the surrounding structures of the spine.
- Tear of the fibrous ring, a painful disease in which there is a tear in the outer layer of the intervertebral disc.
How are epidural cortisone injections performed?
There are three methods of steroid injection into the epidural space: the interlaminar, caudal and transforaminal approach.
All procedures involve inserting a fine cannula into the desired position under fluoroscopy.
Before the steroid injection, a contrast staining is carried out to confirm whether the drug reaches the desired site. In most cases, a local anesthetic is administered with the cortisone to temporarily relieve the pain.
An interlaminar epidural injection is usually called a simplified “epidural injection”. It involves inserting the needle into the posterior part of the epidural space and injecting steroids into a wide area.
Similarly, the caudal procedure is carried out on the hiatus sacralis (a small opening directly above the coccyx) to position the needle at the lower end of the epidural space. With both methods, the steroids are often distributed to different spinal segments and cover both sides of the spinal canal.
With the transforaminal procedure, often referred to as a “nerve block,” the needle is positioned to the side of the nerve at the point where it exits the spine and the drug is injected into the nerve sheath.
This allows the delivery of a more concentrated amount of cortisone into the affected area (usually into a segment or side).
The transforaminal infiltrations can also be slightly modified to cover a single nerve more specifically, as well as relieve pain and improve functionality.
All these procedures are performed on an outpatient basis and usually you can resume your normal activities the following day.
Mild sedation is planned for some patients during treatment, but many of those affected only undergo treatment with a local anesthetic into the skin.
What do you feel during the epidural injection?
There does not have to be any special sensations, but you can also feel a slight tingling sensation or pressure during the injection. Depending on the swelling in the area, a burning sensation or mild discomfort may become noticeable when the drug enters the epidural space.
After carrying out the injection, the symptoms are usually gone.
One may perceive a “tingling” on the arms and legs, depending on the point at which the injection was made.
However, if you feel acute pain, you must inform the doctor immediately.
Due to numbness or other discomfort that may occur after the procedure, one may have some difficulty walking independently and getting in or out of the car. This is normal and should pass after a few hours.
You should rest for the rest of the day, but you can resume normal daily activities the next day.
Epidural injection sometimes does not have an immediate effect. It is normal that an improvement in pain only gradually becomes apparent within the first 48 hours.
The effects can last for a few days, weeks and sometimes months.
In some patients, the pain may worsen 2-3 days after the injection. Only then does the improvement begin.
What are the benefits and risks of epidural infiltrations?
- Temporary or long-lasting relief of pain.
- Temporary or long-lasting reduction in inflammation in the area of the spine that causes pain.
- Improved functionality in everyday life without the limitations previously caused by the pain.
- Can help determine the exact location from which the pain originates. This is a problem in patients who have more than one cause of pain.
- Temporary increase in pain.
- Headache is also possible in very rare cases.
- Drug reaction, such as hot flashes or rash.
- Infection at the injection site.
- If a blood vessel has been accidentally damaged, hemorrhage may occur.
- Nerve lesion at the infiltration site.
- Temporary paralysis of the nerves that innervate the bladder and intestines, and consequent temporary dysfunction of the bladder or intestine.
If fluoroscopy is applied, there is minimal radiation exposure at the site of the injection.
Women should always inform the doctor if there is a possibility of pregnancy.
Many apparatus examinations must not be carried out during pregnancy in order not to expose the fetus to radiation. However, if an X-ray is necessary, precautions must be taken so that the child is exposed to very little radiation.
If an epidural injection is performed in the neck area, the complications that occur are much more serious. For example, spinal cord injury, stroke, or death is possible if the cannula is inserted incorrectly.
The doctor uses fluoroscopy for orientation in order to minimize such risks.
During the procedure, various drugs are injected.
These include sedatives, narcotics, local anesthetics, cortisone and other medicines.
Any of these medications, or even the procedure itself, can sometimes cause side effects, including fatigue, temporary numbness, weakness, and pain.
What to do after an epidural infiltration?
- Rest for a few hours and, if necessary, seek help.
- Slowly resume the feasible activities without exaggerating.
- Eat normally again.
- Do not drive or operate machinery for at least 12 hours.
- Do not make any important decisions after treatment for 12 – 24 hours.
- Be accompanied, as fatigue, weakness or numbness may occur.
Inform the doctor about:
- severe and abnormal bleeding;
- persistent chills or fever above 37.8°C;
- significant change in pain in type and severity.
If your own doctor is not available, the nearest ambulance service must be called. Encourage them to inform the responsible pain therapy centre.
- Take medication as usual.
- perform massage with ice as directed by the doctor; you can use heat if ice is not tolerated.
- If the injection site becomes painful, apply a hot towel 2 to 3 times a day for 20 minutes.