It is an injection of long lasting steroid medication in the epidural space – that is the area which surrounds the spinal cord and the nerves coming out of it. When it is performed from the side where the nerve exits the spine, it is called a transforaminal epidural steroid injection (TFESI).
What is the purpose of it?
The steroid injected reduces the inflammation and/or swelling of nerves in the epidural space caused by a torn or bulging disc, bone spur or narrowing of the canal. This may in turn reduce pain, tingling/numbness and other symptoms caused by nerve inflammation/irritation and swelling.
The actual injection only takes a few minutes, but plan to be in the office for one to two hours. This allows for your pre-op and recovery time as well. Your driver must remain in the building during your procedure.
What is actually injected?
The injection consists of a mixture of local anesthetic (like lidocaine or bupivicaine) and the steroid medication (triamcinolone or methylprednisolone).
Will the injection hurt?
The procedure involves inserting a needle through the skin and deeper tissue (like a tetanus shot). So, there is some discomfort involved. However, we numb the skin and deeper tissues with a local anesthetic using a very thin needle just prior to inserting the epidural needle. Also, the tissue in the midline has less nerve supply, so usually you feel strong pressure and not much pain. Most patients opt to receive IV sedation, which makes the procedure easy to tolerate.
How is the injection performed?
The procedure is done with the patient lying on their stomach unless you are having cervical then you will be sitting up in a chair. The patient may be monitored with EKG, blood pressure cuff, and blood oxygen monitoring device. The area to be injected is cleaned with antiseptic solution and then the injection is carried out.
What should I expect after the injection?
Immediately after the injection, you may feel your extremities slightly heavy and may be numb. Also you may notice your pain may be gone or quite less, this is due to the local anesthetic injected. You may also feel sore for two to three days. This is due to the mechanical process of needle insertion as well as initial irritation from the steroid itself. You should start to notice pain relief within three to seven days.
What should I do after the injection?
You should have a driver to take you home. We advise patient to take it easy for a day or two after the procedure and you should be able to return to work the day after and resume normal activities.
How long does the effect of the medication last?
The steroid starts to work in about five to seven days and can last several days to a few months.
How many injections do I have to have?
If the first injection does not relieve your symptoms in about a week or two, you may be recommended to come in for an office visit to discuss further options or have one more injection. Generally we do not repeat injections that do not help your symptoms. You can only have three to six a year.
Will the epidural steroid injection help me?
It is very difficult to predict if the injection will indeed help or not. Generally speaking, the patients who have “radicular symptoms” (like sciatica) respond better to the injections than the patients who only have back pain. Similarly, the patients with a recent onset of pain may respond better than the ones with a long standing history of pain.
What are the risks and side effects?
Generally speaking, this procedure is safe. However, with any procedure there are risks, side effects, and possibility of complications. The most common side effect is pain – which is temporary. The other risks involved are spinal puncture with headaches, infection, bleeding inside the epidural space with nerve damage, worsening of symptoms, etc. The other side effects are related to the use of steroids. These include increase in blood sugar (mainly in diabetics), water retention, suppression of body’s own natural production of steroid, etc.
Who should not have this injection?
If you are allergic to any of the medications to be injected, if you are on a blood thinning medication (ex: Coumadin, Plavix or Aspirin), if you have an active infection going on, if you are pregnant or suspect you may be pregnant, you should not have the injection.