Epilepsy and The Spinal Tap
One test for epilepsy is a spinal tap -- also called a lumbar puncture -- that is performed by withdrawing fluid surrounding the spinal cord (called the cerebrospinal fluid or CSF) and examining it in a lab.
How is a Spinal Tap performed?
The following procedure could be used:
- Diagnose conditions such as inflammation or infection of the brain
- The pressure surrounding the spine and brain should be measured
- Relieve pressure in the head
- Apply spinal anesthesia
- For an X-ray scan, inject dye
- Use injectable medications such as baclofen
The CSF test can be used to diagnose disorders in the central nervous system, such as those affecting the brain or spinal cord (the meninges). CSF is a mixture of glucose, proteins and other blood substances. These are the results of CSF lab testing
- White blood cells: The types and number
- The amount of glucose
- How many proteins are there?
- A high level of bacteria or fungi in the body.
You may be required to have special tests done on your CSF in order to detect abnormal proteins or autoimmune antibodies.
If a spinal tap is performed to inject drugs, testing of the CSF might not be required.
A Spinal Tap Preparation: What Can You Expect?
Keep to your normal eating habits. Before the test, there are no restrictions on fluids or dietary requirements. Before the test, ask your doctor about how to stop drinking alcohol, using blood thinners, or taking aspirin. Talk to your doctor about any allergies you may have to latex and other medication. As you are not allowed to drive right away after the test, make arrangements for transport.
During a spinal tap, you generally will either lie on your side with your knees drawn as close to your chest as possible and your chin toward your chest, called a fetal position, or sit with your arms and head resting on a table. An interventional radioologist may perform a spinal tap using an Xray machine. You will be lying flat on your stomach if this procedure is performed.
Sterile drapes will be used to cover the affected area after cleaning it with an antiseptic. An injection of local anesthetic, which is pain-relieving medication, will be made to the affected area. A slight burning sensation may occur.
A needle is placed in the lower back, between the two lumbar vertebrae. Avoiding the spinal cord, a needle is placed in the lower back between two lumbar vertebrae. This allows for the doctor to reach the affected area without having to remove any tissue or skin. After fluid has been collected, the stylet must be removed. A hollow needle is left behind to collect CSF. This can sometimes cause pressure. It is possible to penetrate the spinal canal and collect fluid or inject medication. During this test, the needle does not touch the spinal cord. You may feel some discomfort or have a minor headache. Once the medication or fluid has been administered, the needle must be removed. A small bandage will be applied to the area.
You may be asked to give a sample of blood from one vein on your arm. This will then be tested in the laboratory. The spinal tap may have been done in order to inject medicine. In this case, the blood sample will not likely be taken.
Side effects and risks of a spinal tap
Approximately 10% to 20% of people develop a spinal headache (one that worsens when sitting or standing). There is very little risk of getting infected. Sometimes, bloody discharge can be caused by a tiny blood vessel being pierced. There is no treatment. It is rarely painful. However, a few moments of discomfort may occur if the needle touches sensitive nerve tissue. The following is the care for a spinal tap
You will need to lay flat after a spinal tap. You will be instructed to lie flat for a different amount of time depending on what procedure you had. For the first day following lumbar puncture, avoid strenuous exercise or intense physical activity. If you have a headache, lay down as much as possible and drink plenty of fluids. Contact your health care provider if the headache persists. Stay hydrated and drink plenty of fluids the day of the lumbar puncture and the day after (regardless of headache). How to contact the doctor after a spine tap
You notice any unusual drainage, including bloody discharge, at the puncture site You develop a fever Your headache persists, especially if the headache is worse with sitting or standing Your pain symptoms worsen If your headache worsens, you might need a blood patch where you got your spinal tap. You will need to go back to the exact spot where the spinal tap was placed and inject some of your blood. This can usually bring immediate relief.
After the Spinal Tap
Following a spine tap procedure, your condition will continue to be monitored. The nurse will then discuss with you the post-procedure instructions. The nurse will give you a copy of the instructions that you can follow at home.
Although the results of your spinal tap are discussed with the doctor within 24 hours, others may take longer.