Overview of Suboccipital Puncture
A suboccipital puncture is a procedure developed over a century ago. It’s a way to get a sample of cerebrospinal fluid (CSF), which is the fluid that surrounds and protects your brain and spinal cord. Doctors can test this fluid to help diagnose various conditions. It’s an alternative to a method called lumbar puncture, which takes a sample from your lower back area. The suboccipital puncture is done behind the skull, beneath a bone called the occipital bone.
The method was first performed by a doctor named Obregia in 1908. Later, doctors made modifications to this puncture to better suit different needs. Nowadays, it’s done using a path that angles off to the side, which is called a “lateral trajectory”.
Later on, in the 1960s, another type of puncture started gaining popularity. This is known as a lateral C1-C2 cervical puncture. It’s performed on the side of the neck, at the level of the first and second cervical vertebrae. This technique allows not only for obtaining CSF, but also for injecting drugs into the spinal cord or conducting a type of x-ray test known as a myelogram.
Over time, there’s been a debate on whether these punctures are necessary. Some argue that a lumbar puncture, in which fluid is taken from the lower back, can give all the information needed without needing to puncture the neck or the area beneath the skull. However, these neck and skull punctures remain useful in situations where a lumbar puncture can’t be done, or isn’t safe.
In 2017, a new iteration of the suboccipital puncture was introduced. Named the lateral atlantooccipital space puncture, it works much like the original suboccipital puncture but uses a lateral or side approach. It’s less risky because there’s no danger of puncturing the medulla oblongata, a vital part of your brain. This new technique might lead to a revival in the use of the suboccipital puncture.
Overall, both the suboccipital and C1-C2 cervical punctures are important techniques for doctors to know and use. Depending on the situation, one may be a better choice over the other.
Anatomy and Physiology of Suboccipital Puncture
The cisterna magna is a space filled with fluid located between two parts of the brain – the cerebellum and the medulla oblongata. It’s directly connected to a channel inside the brain called the fourth ventricle. Doctors have to be careful when accessing this area, because if a needle accidentally punctures the medulla oblongata, it can be harmful.
In most people, there’s a wider space around the area of the C1-C2 vertebrae (the top two bones in the spine), which can be used to safely access the cisterna magna. However, the space gets narrower as it goes downwards beyond the point of C2, making it less suitable for access with a needle. The third part of the vertebral artery, a major artery supplying blood to the brain, runs through an arch in the C1 vertebrae and moves in different directions before it reaches the base of the skull.
This artery often curves after coming out from C2, then dips down again to enter C1. Therefore, it lies over one side of the spinal canal, between the C1 and C2 vertebrae. In most people, this V3 segment is located in front of the spinal canal. When a needle is inserted at this point, the chance of damaging the artery is very low, especially if the needle is aimed towards the back part of the canal. It’s also recommended to slightly turn the patient away from the side being accessed to further reduce the possibility of vessel damage.
There’s also another artery called the posterior inferior cerebellar artery, or PICA. In a few cases, this artery extends lower down the back of the skull, but it’s less likely to be touched during a needle insertion.
Sometimes, during development, the vertebral artery keeps an extension which, in adults, enters into the spinal canal between C1 and C2, instead of entering the C1 vertebra. This is called a C2 segmental type vertebral artery. In rare cases, there’s an extra version of the artery above and below C1. This is known as a duplicated vertebral artery, which happens when the extension is kept, and there’s a second vertebral artery that still enters through the C1 vertebra.
Why do People Need Suboccipital Puncture
If your doctor is looking for ways to diagnose or treat a condition in your central nervous system (brain and spinal cord), they may suggest a suboccipital puncture or lateral C1-C2 cervical puncture. These are types of procedures where a needle is inserted into your spine to remove a small amount of fluid or deliver medication.
Circumstances that might prompt your doctor to recommend a suboccipital puncture include the following:
- Imaging tests of the spinal cord (known as cervical myelography)
- Visualizing the flow of cerebrospinal fluid in the brain and spine (cisternography)
- Examining certain parts of the brain (ventriculography)
- Injecting medication directly into the cerebrospinal fluid (intrathecal chemotherapy)
- Treating infections by delivering antibiotics or antifungals directly into the cerebrospinal fluid
- Performing a stem cell transplant
- Conditions like inflammation of the protective layers of the spinal cord in the lower back region (arachnoiditis), severe narrowing of the spine (lumbar stenosis) or stiffness of the spine (ankylosis)
- Birth defects that result in a split spine or hidden abnormalities in the spine in the lower back region (spinal dysraphism)
- Any situation where the spinal cord is completely blocked or at risk of infection, or situations where the surgeon needs to locate the top edge of a complete blockade in the spine
Reasons for considering a lateral C1-C2 cervical puncture are similar to that of a suboccipital puncture. The key reasons include:
- Treatment of inflammation, severe narrowing or stiffness of the spine at the lumbar area
- Conditions resulting from birth defects in the lower back
- Instances where the spinal cord is completely blocked or has an infection
- Delivering chemotherapy or antibiotics directly into the cerebrospinal fluid
- Better visualization of the neck region during a type of imaging test known as a myelogram
Your doctor will weigh various factors before suggesting which procedure is best for you.
When a Person Should Avoid Suboccipital Puncture
Suboccipital puncture, a medical procedure that involves a small puncture made at the base of the skull, isn’t performed commonly. There are several reasons why this procedure might not be a good idea for every patient. Some reasons include:
– Physical abnormalities where the skull joins the spine.
– Chiari malformation, a condition in which brain tissue extends into the spinal canal.
– Down syndrome, a genetic disorder that affects physical and mental development.
– Difficulty getting the head in the right position for the procedure.
– Significant heart and lung health problems.
– Presence of something taking up space inside the skull, such as a tumor or fluid.
– Signs of herniation, or when an organ pushes through an opening in the tissue or muscle that holds it in place.
– A blood disorder that can’t be corrected and makes it difficult to stop bleeding after surgery.
There are also factors that can make a lateral C1-C2 cervical puncture, a procedure that involves a small puncture at the side of the neck, not the right choice. These reasons can include:
– Chiari malformation.
– Presence of a tumor at C1–C2, the first two cervical vertebrae of the spine.
– Narrowing of the spinal canal at C1–C2.
– Signs of herniation.
– Same blood disorder mentioned earlier.
– A variant where a vertebral or posterior inferior cerebellar artery crosses the posterior spinal canal at C1–C2.
– A condition where the flow of cerebrospinal fluid is blocked, causing fluid buildup in the brain.
– If a patient is uncooperative and has low-lying tonsils.
– Achondroplasia, a type of short-limbed dwarfism.
– A condition where a pad of inflammatory tissue causes pressure on the spinal cord at C2.
Equipment used for Suboccipital Puncture
The suboccipital puncture is a medical procedure done at the back of your skull, close to your neck, which needs some specialized equipment. Here’s a simple breakdown of what a doctor might use:
- A fluoroscopic machine – This is a special type of medical device that lets the doctor see an x-ray like image of your body in real time.
- A 20-22 gauge needle – This is the size of the needle that they would use. The higher the gauge, the thinner the needle. So, this would be a relatively thin needle.
- Local anesthetic medication – This is a drug that’s applied to a specific area of your body to numb it, so you don’t feel pain.
- CSF collection tray (lumbar puncture tray) – CSF stands for cerebrospinal fluid. This is a tray used for the procedure when they have to collect some of this fluid. A lumbar puncture is another name for a spinal tap.
- Myelographic dye (if a myelogram is indicated) – This is a special dye that may be used in an imaging study of your spine called a myelogram. Doctors use it to view your spinal column more clearly.
Who is needed to perform Suboccipital Puncture?
The procedure called suboccipital puncture is carried out by a team of experienced healthcare professionals to ensure the best results. This team includes:
A neuroradiologist, a doctor who specializes in using imaging techniques like MRI and X-ray to visualize the brain and nerves. They provide key information about the patient’s condition.
A neurosurgeon, a doctor who specializes in operating on the brain and other parts of the nervous system. They perform the main part of the procedure.
A radiation technologist, a professional who operates imaging machines and implements safety measures to prevent unnecessary radiation exposure. They aid in getting clear and precise images required for the procedure.
Additionally, a nurse assists throughout the process, providing care and support to the patient before, during, and after the procedure.
Preparing for Suboccipital Puncture
Before your doctor performs a certain procedure on you, they need to go through several steps to make sure it’s safe. This procedure could be an x-ray, a scan, or anything else that allows them to see what’s going on inside your body.
Firstly, your doctor will take a look at your medical history or previous records. This helps them know whether it is safe for you to proceed with the procedure or not. They will check your current medications. This is important in case one of your medications could potentially mess up the results of the test or cause side effects during the procedure. They will also check if you have had any past allergic reactions to “contrast agents” which are special substances often used to improve the quality of the imaging during the procedure.
Next, an imaging test will be done on your head. This is called a computed tomographic (CT) scan. It’s a type of x-ray that makes detailed pictures of your body. It helps to determine if there are changes in your bones or if there are abnormalities in your skull. Additionally, an angiography of your neck might also be done using either CT (CTA) or magnetic resonance imaging (MRI, MRA). This is a technique that involves using a dye and special x-rays to look at the blood vessels in your neck. It allows doctors to identify any peculiarities in arteries that could make the procedure risky.
Your doctor will also carry out some blood tests, specifically tests that check how well your blood can clot. If your blood does not clot well, you could bleed excessively during the procedure, which can be dangerous.
Your doctor may tell you to stop taking certain medications that can affect your blood’s ability to clot. This is following standard medical advice or guidelines.
Lastly, your doctor needs to ensure you are physically able to maintain certain postures (like lying down on your back, sitting, lying on your side, or lying face down) during the procedure. This is important for your safety and to successfully complete the procedure. The area where the procedure will be done will then be cleaned and sterilized to prevent any potential infection.
How is Suboccipital Puncture performed
A suboccipital puncture is a procedure performed by doctors where a needle is inserted into the area at the back of your neck, near the base of your skull. This procedure can be used to collect a sample of the fluid that surrounds your brain and spinal cord, which is known as cerebrospinal fluid (CSF). It can also be used to inject drugs, dyes or other substances into this area.
Several methods can be used for this procedure, and the one your doctor chooses can depend on your condition and the doctor’s experience. Some techniques require you to lie on your side, while others require you to lie face down or on your back. In all cases, your doctor will numb the area with local anesthesia, then carefully guide the needle into the right spot.
After the needle is in place, your doctor will wait until they see a clear fluid flowing out. This fluid is the CSF, and it can be collected for testing. If your doctor is performing a procedure that involves injecting a substance into the area, they will do so meticulously. Once the procedure is complete, the needle will be removed, and the doctor will apply pressure to the puncture site for a minute or so to stop any bleeding.
Another version of the procedure, the lateral C1-C2 technique, is performed under X-ray guidance, and can be done with you in various positions. This method involves the needle being entered at a specific point on the side of the neck. During this procedure, your doctor will check periodically with X-ray images to ensure the needle is in the correct position. Again, once the fluid is seen or the necessary operations are completed, the needle is removed, and pressure is applied to the area.
In some cases, a dye may need to be injected into the area so doctors can see the structures in your spine more clearly. This helps them diagnose any issues. If this is necessary, only a specific type of dye that is safe for your nervous system will be used.
Your doctor will advise you of any specific precautions you need to take following your procedure. This could involve changing your position or avoiding certain activities for a period of time.
Possible Complications of Suboccipital Puncture
Suboccipital and lateral cervical punctures are medical procedures that, even though they need a lot of skill to be done, can sometimes lead to complications. Both are procedures to obtain a sample of cerebrospinal fluid (CSF)–the fluid present in your brain and spine–for further examination.
A suboccipital puncture involves getting a sample of fluid from the region beneath the occipital bone, which is located at the lower back part of your skull. Some possible complications of this procedure include:
– Infection
– Bleeding, also known as “hemorrhage”
– Headache after the procedure
– Gathering of CSF in a particular area
– Damage to the nerves (Neurological injury)
– Laceration or small cut to PICA (a specific blood vessel in the brain)
– Pain in the throat due to stimulation of certain nerves in the area
On the other hand, a lateral cervical puncture involves inserting a needle on the side of your neck to get a fluid sample. It’s possible after this procedure to experience:
– A tingling sensation or electric shock, also known as Lhermitte sign, due to accidental needle insertion into the spinal cord
– Infection
– Bleeding into the spaces surrounding your brain and spinal cord (subarachnoid hemorrhage)
– Accidentally puncturing the vertebral artery, a major blood vessel in the neck
– Accidentally puncturing PICA (this is rare)
– Pain at the site where the needle was inserted
– Damage to the nerves
– Anxiety, headaches and muscle spasms in the neck
– Leakage of CSF
– Feeling queasy or nausea
Both these procedures should be conducted by a medical professional with great care and expertise to reduce the risk of complications.
What Else Should I Know About Suboccipital Puncture?
There are two techniques to take samples of your spinal fluid, when the usual method isn’t suitable. These are called the suboccipital puncture, which is done at the base of your skull, and the C1-C2 puncture, done at the top of your neck.
These methods aren’t often used, but provide a way to collect spinal fluid when a standard method, known as a lumbar puncture (usually done in your lower back), isn’t suitable for you.
The C1-C2 puncture has slightly more chance of minor side effects (4.9%) compared to the lumbar puncture (3.4%). However, major complications from a C1-C2 puncture are very rare, happening in less than 0.05% of cases. The most common issue associated with this procedure is related to neck positioning during the procedure.
To ensure the C1-2 puncture is done properly and safely, doctors use a type of real-time X-ray called a lateral fluoroscopy. This monitors the accurate placement of the needle and helps to prevent any of the contrast medium (a specific type of dye) from accidentally being injected into your spinal cord.
Finally, you should know that getting a headache after a C1-C2 puncture is less frequent compared to after a lumbar puncture. Even if a headache does occur, it generally lasts less than 24 hours and happens in about 10% to 25% of patients.