Overview of Cervical Epidural Injection
When people have a medical condition that causes neck pain and other symptoms called cervical radiculopathy, they can sometimes find relief from a treatment called a cervical epidural injection. But this option is usually only considered when their symptoms have persisted for at least a month and a half and didn’t get better with other, less invasive treatments. As well, doctors will consider other options if the condition is getting progressively worse.
Cervical radiculopathy is a condition that affects about 83 out of every 100,000 people a year. Generally, it gets better with non-surgical treatments and doesn’t require a cervical epidural or surgery. Interestingly, studies have had mixed results on how effective cervical epidural pain relief is. But it seems to significantly reduce pain overall.
People with chronic recurring neck pain and related symptoms can benefit from cervical epidural injections. The procedure is considered successful if it leads to a 50% reduction in pain three months following the treatment, a result that half of the patients experience after the procedure. Initially, this treatment involves one injection. Then, it’s followed by one or two more injections over the next two to four weeks.
The symptoms of cervical radiculopathy can be caused by several different factors, ranging from age-related degeneration to conditions like diabetes or cancer. Conditions such as slipped discs or degenerative disc disease can also lead to cervical radiculopathy. The most common cause of this condition is the compression of nerve roots due to a narrowed spinal canal or herniated disc in the neck. It’s worth mentioning that people with a slipped disc or degenerative spinal conditions usually do not require cervical epidural injections.
Cervical radiculopathy can cause chronic neck pain which requires intervention when conservative treatments don’t work. There can be risks associated with the injection procedure. These could include infection, headaches related to the spine, allergic reactions, nerve damage, and exceptionally rare cases, paralysis or death. There are different methods to administer a cervical epidural injection. The transforaminal approach is better targeted but tends to have a higher risk of complications than the intralaminar technique.
Anatomy and Physiology of Cervical Epidural Injection
The process of a cervical epidural involves the use of drugs known as corticosteroids and possibly some local anesthetics. These are injected into a key space in the spinal area, known as the epidural space. This space is situated between the bony segments of your spine (vertebrae) and a crucial covering called the dural sac.
Sometimes, the nerves in the neck region get damaged because they are compressed or squished, and this leads to inflammation, which we often experience as pain. A cervical epidural corticosteroid injection can help to reduce the swelling and inflammation right where these nerves are compressed, which can lead to relief from pain. This can be very helpful for patients suffering from cervical radiculopathy, a condition where they experience both neck pain and shoulder and arm pain. The doctor performing these procedures needs to understand the anatomy of the neck region of your spine.
The epidural space itself is rather like a triangle in shape. It extends upward through an opening at the base of your skull (foramen magnum), and travels downward to an opening at the bottom of the spine (sacral hiatus). The inner side of this space is lined by the thecal sac which is protected by a covering called the dura mater. This acts kind of like a sheath that protects the spinal nerve and clusters of nerve cells on the posterior or back side, known as the dorsal root ganglia. The outer side of the epidural space is made up of the spinal canal and another layer of bone called the periosteum.
The front side of this space is lined by the posterior longitudinal ligament, while the back side is formed by both the lamina (part of the bone in your vertebrae) and another ligament known as the ligamentum flavum. This particular ligament is loose in the middle for about half the patients, and in these cases, there is no ligament between the spinous processes of the vertebrae (the bony projections you can feel on your back).
The sides of the epidural space include structures known as the pedicles and intervertebral foramen, another key opening. This foramen is made up of the top and bottom pedicles, with the upper joint of the facet joint forming the back wall of the foramen. The front wall is formed by the vertebral disk and another part of the bone known as the endplate. Within the epidural space, there is fatty tissue, arteries, lymph, certain structures called arachnoid granules, a network of veins, and the spinal nerve roots.
The spinal nerve roots originate from the spinal cord. Both front (ventral) and back (dorsal) nerve roots combine to form the spinal nerves which exit at the bottom of the foramen. They exit along with the thecal sac forming a root sleeve. The covering known as the dura mater ends at the dorsal root ganglion or cluster of nerve cells.
The blood supply to the spinal area is provided by several arteries including the vertebral, ascending cervical, subclavian, and deep cervical arteries. These arteries enter the foramen and then divide into the back and front cervical radicular arteries.
Why do People Need Cervical Epidural Injection
A cervical epidural injection is a treatment often used when patients experience symptoms such as numbness, burning sensations, or tingling, usually related to nerve pain. These symptoms can worsen over time, leading to increased weakness or changes in sensory perception. The healthcare provider keeps a close eye on these symptoms to monitor their progression.
Sometimes, patients might experience intense pain that gets progressively worse; however, there may not be any significant worsening in their neurological condition. In these cases, doctors often choose a corticosteroid shot over surgery. This form of treatment is less invasive, but able to effectively manage the patient’s pain.
Before the actual treatment can take place, patients typically undergo a magnetic resonance imaging (MRI) scan or a computed tomography (CT) scan. These scans help confirm whether there’s pressure on the root of a nerve, which could be due to natural age-related changes or a problem with an intervertebral disc, which is a type of cartilage found between the bones in your spine. Once this is confirmed, the patient can then move forward with the cervical epidural injection procedure.
When a Person Should Avoid Cervical Epidural Injection
An epidural corticosteroid injection can’t be given to everyone. For instance, if a person has an active infection, they cannot have this injection. Also, having a condition that affects the blood’s ability to clot, known as an uncontrolled coagulopathy or bleeding disorder, would be a reason not to undergo the procedure. This also applies to people who take a lot of oral anticoagulants – medicines that stop your blood from clotting.
Other reasons why the procedure might be unsafe include showing a fast deterioration in nerve-related symptoms, like increasing weakness, or needing emergency neurosurgery for conditions like grade four spondylolisthesis, a spinal condition where a lower vertebra slips forward onto the bone directly beneath it.
Additionally, there are some cases where the procedure may be somewhat unsafe, also known as relative contraindications. This includes folks with untreated medical conditions like hypertension (high blood pressure) or diabetes, and those who are pregnant (since fluoroscopy, an imaging technique that uses X-rays to obtain real-time moving images of the body, isn’t safe during pregnancy).
Equipment used for Cervical Epidural Injection
When a doctor performs a cervical epidural corticosteroid injection, different equipment is needed. This includes a topical anesthesia like lidocaine, which helps numb the area, a low resistant syringe, and a special type of needle called a Tuohy epidural needle or a Quincke spinal needle. The needle size typically ranges between 17 to 20 gauge or 22 to 25 gauge respectively.
Moreover, the doctor also uses imaging tools during this procedure to increase its accuracy. Most commonly, a device called a C-arm fluoroscope is used. This is a big machine that allows the doctor to see the exact area where the needle should go. For safety, the doctor performing the procedure will also wear a protective lead apron.
The doctor will use a special dye to help ensure that the needle is correctly placed. After making sure the needle is in the right spot, a mixture of local anesthetic, saline (which is like salt water), and a medication called “corticosteroids” is injected into the epidural space, a space around your spinal cord. The type of corticosteroid used can differ, and can be either particulate or non-particulate, depending on the specific procedure.
Who is needed to perform Cervical Epidural Injection?
A cervical epidural injection is a procedure which is typically done in a clinic and not in a hospital. This procedure is often performed by doctors who specialize in managing pain. However, there are also various other types of doctors who can carry out this procedure. This includes a physiatrist (a physician who specializes in physical medicine and rehabilitation), an interventional radiologist (a doctor who uses medical imaging to guide minimally invasive surgical procedures), an interventional neurologist (a doctor who performs non-surgical procedures to diagnose and treat diseases of the brain, neck, and spine), an anesthesiologist (a doctor who gives anesthesia, a medicine to prevent pain and discomfort during surgery), and sometimes, even a spine surgeon.
During the procedure, there’s usually a radiology technician present to assist with operations of the C-arm, a type of X-ray machine that can provide real-time high-resolution X-ray images. This helps guide the doctor during the procedure. Also, nursing staff are on hand to look after the patient both before and after the procedure.
Preparing for Cervical Epidural Injection
A cervical epidural injection is a procedure that a doctor might suggest you if you’re suffering from persistent neck or back pain which might be due to a damaged disc or some other condition. This injection can help to reduce swelling, inflammation, and pain. The procedure is typically done at a facility specifically equipped for surgery, and that has an instrument called a fluoroscope. A fluoroscope lets the doctor see the area they’re working on in real-time, making the procedure safer.
The injection is usually done by a doctor who is an expert in treating spine and pain-related issues. It’s required because there is a risk of serious complications if it’s wrongly done. The procedure may take a few minutes or up to half an hour, based on your body’s structure.
During the procedure, it’s essential that you be awake and interactive so it is often performed without a heavy dose of sedatives. This is done to allow you to communicate any issues or discomfort immediately during the injection, making it safer.
Before the injection, doctors will likely want to have a more detailed look at the spine using advanced imaging techniques like an MRI scan or a CT scan. This will help them understand better what might be causing your symptoms and ensure the injection is the best option for you. If these images don’t give a clear answer, or if it’s not possible to get these scans, further testing might be necessary.
How is Cervical Epidural Injection performed
The procedure described here is usually carried out with the help of a technique called fluoroscopy. This helps doctors see what’s happening inside your body real-time. The best visibility can be offered by a CT scan fluoroscopy, but it’s not commonly used because it exposes you to a lot of radiation.
The first step is to properly position you. You’ll be made to lie face down with your arms by your side and your head supported and bent forward. This will open up the spaces between the bones of your back called the interlaminar spaces. The area around your back will be cleaned with a special solution to make sure it’s free of germs.
There are two ways to carry out the procedure: the interlaminar method (done between the bones of your spine) and the transforaminal method (done through an opening in your spine called the foramen).
The interlaminar method begins with marking your skin as per the fluoroscopy. Your skin will then be numbed with small needle to avoid any discomfort. It’s important that this needle does not go in too deep to prevent any complications.
Once your skin is numb, a special technique called the “loss of resistance” is used to find the epidural space, the area just outside the membrane surrounding your spinal cord. As the doctor advances the needle towards the painful side of your back, they’ll feel the resistance change as the needle goes through various tissues. Fluoroscopy images will be taken during this process to guide the doctor.
Once they’re fairly certain the needle has reached the epidural space, a type of dye is injected to make sure the needle is in the right place and no blood or spinal fluids are accidentally drawn into the syringe. If everything checks out, a mixture containing corticosteroids (anti-inflammatory medication) and saline, and possibly local anesthetic (to numb the area), is then injected. The entire procedure needs good communication between you and your doctor to make sure you don’t experience any significant discomfort during the injection.
The preferred location for the injection is between the seventh cervical vertebra (C7) and the first thoracic vertebra (T1), because this area has a specific ligament that helps prevent accidental puncture of the spinal cord or the membrane around it.
The transforaminal approach is not commonly used due to the risk of accidentally puncturing a blood vessel. In this method, the needle is inserted using a side view on fluoroscopy which helps the doctor avoid the blood vessels in the foramen. Only a non-particulate corticosteroid (which can’t block blood vessels) is used in this method along with a local anesthetic and saline. You and your doctor need to communicate closely during this procedure too.
There’s also a new method being studied where the doctor uses ultrasound instead of fluoroscopy for the transforaminal injection. The advantage here is that the ultrasound can see the blood vessels. But for the interlaminar approach, ultrasound might not be very helpful because it can’t penetrate bone to see the epidural space.
Possible Complications of Cervical Epidural Injection
Problems may arise if the needle used during an epidural corticosteroid injection touches the spinal cord, blood vessels, spinal nerves or becomes contaminated. Serious complications are not common with this procedure, but they do happen in about 16.8% of instances.
Dangerous conditions such as bleeding (hemorrhage) or blockage of blood flow to a part of the body (infarction) could occur during this injection. In some severe cases, fatalities have occurred, especially when the injection is made between the openings on the side of the spine (transforaminal approach).
The exact cause of these complications isn’t well-known. Some theories suggest that they might be because of a blockage of blood vessels due to a clot (emboli) or a hardened blood clot (thrombus). Others include the widening of the main artery that carries blood away from the heart (aortic dissection), constriction of blood vessels, or accidental puncture of the protective layer covering the brain and spinal cord (dural puncture).
Some other serious complications that may occur include epidural hematomas (a collection of blood in the space around the spinal cord), spinal abscesses (pus-filled areas within the spine), and cerebral vascular accidents (problems with the blood supply to the brain), all of which can happen after the injection.
Injection procedures used to deliver corticosteroids to the space around the spinal cord (epidural space), either between the two layers of the protective covering of the spinal cord (interlaminar) or through the small openings to the side (transforaminal), can also have complications. These may include nerve root injuries, epidural or subdural hematomas (bleeding around the spinal cord or beneath the dura), temporary sensory changes or loss of vision, infections or abscesses in the epidural space, injuries to the spinal cord, paralysis, and even death.
The use of corticosteroids like dexamethasone for the injection has, fortunately, not been linked with any severe complications. However, the most common side effects reported include neck pain (6.7% of patients), headache (1.7%), insomnia (1.7%), and a response where a patient faints or nearly faints due to changes in heartbeat and blood pressure (vasovagal reaction at 1.5%). Dural punctures occur in 0.3% of patients undergoing the transforaminal approach and between 0.25% and 2% for those receiving the interlaminar injection. Headaches appear in 4.5% of those going through the interlaminar method. Similarly, up to 18% of patients might experience a temporary increase in the pain that extends from the spine to the limbs (radicular pain) after the injection.
What Else Should I Know About Cervical Epidural Injection?
The success of neck (cervical) epidural injections, which are injections given around the spinal cord to alleviate pain, largely depends on the cause and severity of your condition. After the initial treatment, some people may experience the return of their symptoms – this can happen to about one third of patients suffering from compressive cervical radiculopathy, which is a condition where the nerves in the neck get compressed or squeezed.
It’s important to note that multiple injections over a course of one year may help in better managing the pain. These injections are quite helpful in briefly relieving pain, although there’s still ongoing research to compare the effectiveness of different treatment techniques.
Injections given in-between the small bones of the spine (known as the intralaminar approach) are more well-researched when compared to injections given through the small bony openings on the side of the spine (transforaminal approach). These injections are found to be quite effective in managing pain caused by neck disc herniation, spinal stenosis (where the space around the spinal cord narrows), and postoperative pain. On the other hand, the transforaminal approach doesn’t have as strong evidence supporting its effectiveness and might have more side effects.
Despite having some supportive evidence, researchers agree there’s a need for more well-planned trials to provide stronger proof. For short-term pain relief, spanning less than six weeks, cervical epidural injections show moderate effectiveness. However, there isn’t much information about their long-term effects. Similar studies have been conducted for both intralaminar and transforaminal injections.
These injections have shown mixed results. While they help significantly alleviate pain when compared to an injection with a local anesthetic, they may not show a noticeable reduction in pain three weeks after the injection.
Interestingly, some studies have shown that after a cervical epidural, symptoms disappeared entirely in about a quarter of patients, 40% experienced a 75% reduction in their pain, while approximately 32% didn’t report any change in their pain levels. Of the patients with nerve inflammation and abnormalities seen on medical imaging, just over a third reported that their pain was halved or even more reduced.
