Epilepsy: Lumbar Puncture (Spinal Tap)

http://www.webmd.com/epilepsy/lumbar-puncture-spinal-tap

WebMD Medical Reference in Collaboration with The Cleveland Clinic

What Is a Lumbar Puncture?

One test for epilepsy is a lumbar puncture, also called a spinal tap, which is a procedure in which the fluid surrounding the spinal cord (called the cerebrospinal fluid or CSF) is withdrawn through a needle and examined in a laboratory.

Why Is the Lumbar Puncture Procedure Performed?

This procedure may be performed to:

• Measure the pressure around the brain and spinal cord.
• Relieve pressure in the head.
• Give spinal anesthesia.
• Inject dye for an X-ray diagnostic test.
• Inject medications (such as haclofen).

Testing the CSF can help in the diagnosis of disorders of the central nervous system that may involve the brain, spinal cord or their coverings (meninges). The CSF contains glucose (sugar), proteins and other substances found in the blood. When the CSF is examined in the laboratory, the following are evaluated:

• The number and types of white blood cells.
• The level of glucose.
• The types and levels of proteins.
• The presence of bacteria, fungi or abnormal cells.

NOTE: Testing of the CSF may not be necessary if the spinal tap procedure is done to inject a medication (such as haclofen).

What to Expect

Preparation for the procedure

• Maintain your regular eating schedule. There are no dietary or fluid restrictions before the test.
• Ask your doctor for specific guidelines about discontinuing alcohol use, aspirin products and anticoagulant medications before the procedure.
• Tell your doctor if you are allergic to latex or any medications.
• Please make arrangements for transportation, as you should not drive immediately after the test.

Description of the procedure

You will either lie on your side with your knees drawn as close to your chest as possible and your chin toward your chest or sit with your arms and head resting on a table. After cleaning your back with an antiseptic, sterile cloths (called drapes) will be placed around the area. A local anesthetic (pain-relieving medication) will be injected into the area on your back. You may feel a slight burning sensation. When the area is numb, a hollow needle is inserted in the lower back between two lumbar vertebrae. This sometimes causes pressure. The spinal canal is penetrated and fluid is collected or medication is injected. The spinal cord is not touched by the needle during the test. You may feel some discomfort or have a minor headache. The needle is removed after the medication has been injected or fluid is removed. The area will be covered with a small bandage. A blood sample will be taken from a vein in your arm and tested, along with the spinal fluid, in the laboratory. NOTE: if the procedure was done to inject medication, a blood sample may not be taken.

Side effects and risks of the procedure

• Approximately 10% to 20% of people develop a spinal headache (one that worsens when sitting or standing).
• The risk of infection is extremely low.
• Occasionally, a small blood vessel is pierced, causing bloody discharge. No treatment is needed.
• The procedure is usually not painful, but momentary twinges of pain may be felt if the needle brushes against nerve tissue.

Care after the procedure

• Once a spinal tap is completed, you will be instructed to lie flat. The time spent flat after the tap will vary depending on why you received the procedure.
• Avoid strenuous or vigorous exercise for a day or so following the lumbar puncture.
• 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.
• Drink 2 1/2 quarts of liquid the day of the lumbar puncture and the day after (regardless of headache).

When to Contact the Doctor

Call your local doctor immediately if:

• You notice any unusual drainage, including bloody discharge, at the puncture site.
• You develop a fever.
• Your headache persists.
• Your pain symptoms worsen.

After the Test:

You will be monitored for a few hours. At that time, the nurse will discuss post-procedure instructions with you. You will be provided with a written form of these instructions to follow at home.

The results of your study will be discussed with your referring physician within 24 hours.

For the First 24 Hours After the Test:

1. Remain flat on your back as much as possible.
2. Drink at least 2 1/2 quarts of fluid.
3. Notify your doctor if you experience any drainage from the puncture site, or develop a headache.

Lumbar Puncture (LP)

http://www.cooperhealth.org/content/greystone_21917.htm




(Spinal Tap, Spinal Puncture, CSF Collection)

Procedure Overview

What is a lumbar puncture?

A lumbar puncture (LP), also known as a spinal tap, is a diagnostic and/or therapeutic procedure performed by a physician. The procedure is performed by inserting a hollow needle into the subarachnoid space in the lumbar area (lower back) of the spinal column. The subarachnoid space is the canal in the spinal column that carries cerebrospinal fluid (CSF) between the brain and the spinal cord.

CSF is a clear fluid that bathes the brain and spinal cord while protecting it, like a cushion, from exterior injury. The fluid is produced and reabsorbed in the brain on a continuous basis. CSF is composed of cells, water, proteins, sugars, and other vital substances that are essential to maintain equilibrium in the nervous system.

Click Image to Enlarge

Other related procedures that may be used to diagnose problems with the spine or brain include myelography (myelogram), computed tomography (CT scan), or magnetic resonance imaging (MRI). Please see these procedures for additional information.

Anatomy of the spine:

The spinal column is made up of 33 vertebrae that are separated by spongy disks and classified into distinct areas.

• The cervical area consists of seven vertebrae in the neck.
• The thoracic area consists of 12 vertebrae in the chest area.
• The lumbar area consists of five vertebrae in the lower back area.
• The sacrum has five, small fused vertebrae.
• The four coccygeal vertebrae fuse to form one bone, called the coccyx or tailbone.

The spinal cord, a major part of the central nervous system, is located in the vertebral canal and reaches from the base of the skull to the upper part of the lower back. The bones of the spine and a sac containing cerebrospinal fluid surround it. The spinal cord carries sense and movement signals to and from the brain and controls many reflexes.

Reasons for the Procedure

A lumbar puncture may be performed for various reasons. The most common reason is to remove a small amount of CSF for examination and diagnosis of various disorders. CSF is tested for red and white blood cells, protein, glucose (sugar), clarity, color, and the presence of bacteria, viruses, or abnormal cells. Excess CSF may also be removed in patients who have an overproduction or decreased absorption of the fluid.

A lumbar puncture procedure may be helpful in diagnosing many diseases and disorders including, but not limited to, the following:

• meningitis - an inflammation of the membrane covering the brain and spinal cord. The inflammation is usually the result of a viral, bacterial, or fungal infection, or the result of exposure to toxins or abnormal cells.
• encephalitis - an inflammation of the brain that is usually caused by a virus.
• certain cancers involving the brain and spinal cord
• bleeding in the subarachnoid space
• Reye syndrome - a potentially fatal disease that causes severe problems with the brain and other organs. Although the exact cause of the disease is not known, there has been an association between giving aspirin to children and the development of Reye syndrome. It is now advised not to give aspirin to children during illnesses, unless prescribed by your child's physician.
• myelitis - an inflammation of the spinal cord or bone marrow.
• neurosyphilis - a stage of syphilis during which the bacteria invades the central nervous system.
• Guillain-Barré syndrome - a disorder in which the body's immune system attacks part of the nervous system.
• demyelinating diseases - diseases that attack the protective coating that surrounds certain nerve fibers (e.g., multiple sclerosis or acute demyelination polyneuropathy).

In addition, a lumbar puncture may be used to measure the pressure of the CSF, which flows freely between the spinal column and the brain. The physician measures the pressure during a lumbar puncture using a special tube (called a manometer) that is attached to the lumbar puncture needle.

Finally, a lumbar puncture may be performed therapeutically to inject medications directly into the spinal cord. Some medications that may be given via lumbar puncture (intrathecally) include: spinal anesthetics before a surgical procedure, contrast dye for x-ray studies (e.g., myelography), or chemotherapeutic agents to treat cancer.

There may be other reasons for your physician to recommend a lumbar puncture.

Risks of the Procedure

Because this procedure involves the spinal cord and brain, the following potential complications may occur:

• A small amount of CSF can leak from the needle insertion site. This can cause headaches after the procedure.
• There is a slight risk of infection because the needle breaks the skin’s surface, providing a possible portal of entry for bacteria.
• A temporary numbness to the legs or lower back pain may be experienced.
• There is a risk of bleeding in the spinal canal.
• Should there be increased pressure or swelling in the brain before the procedure, a lumbar puncture can cause fluctuations in the CSF fluid levels, resulting in brain herniation. Herniation is a dangerous event in which the brain stem or top of the spinal column is compressed by swelling of the brain.

There may be other risks depending upon your specific medical condition. Be sure to discuss any concerns with your physician prior to the procedure.

Before the Procedure

• Your physician will explain the procedure to you and offer you the opportunity to ask any questions that you might have about the procedure.
• You will be asked to sign a consent form that gives your permission to do the procedure. Read the form carefully and ask questions if something is not clear.
• Generally, fasting is not required prior to a lumbar puncture unless a sedative is prescribed. Your physician will instruct you prior to the procedure of any necessary fasting requirements.
• Notify your physician if you are pregnant or suspect you may be pregnant.
• Notify your physician of all medications (prescribed and over-the-counter) and herbal supplements that you are taking.
• Notify your physician if you have a history of seizures or if you are taking any prescribed medications for seizures.
• Notify your physician if you have a history of bleeding disorders or if you are taking any anticoagulant (blood-thinning) medications, aspirin, or other medications that affect blood clotting. It may be necessary for you to stop these medications prior to the procedure.
• If the procedure is performed on an outpatient basis, you may be asked to remain in the hospital for several hours following the procedure. You should plan to have another person drive you home.
• Based upon your medical condition, your physician may request other specific preparation.

During the Procedure

A lumbar puncture procedure may be performed on an outpatient basis or as part of your stay in a hospital. Procedures may vary depending on your condition and your physician's practices.

Generally, a lumbar puncture follows this process:

Click Image to Enlarge

1. You will be asked to remove any clothing, jewelry, or other objects that may interfere with the procedure.
2. You will be given a gown to wear.
3. You will be reminded to empty your bladder prior to the start of the procedure.
4. During the lumbar puncture you may lie on the examination table on your side with your chin tucked to your chest and knees tucked to your abdomen. Alternatively, you may sit on the edge of an examination table with your arms draped over a table positioned in front of you. In either position the back is arched, which helps to widen the intervertebral spaces.
5. A lumbar puncture is a sterile procedure. Therefore, your back will be cleansed with an antiseptic solution and draped with sterile towels. The physician will wear sterile gloves during the procedure.
6. The physician will anesthetize the skin by injecting a local anesthetic that numbs the site. This injection may sting for a few seconds, but makes the lumbar puncture less painful.
7. The hollow needle will be inserted through the numbed skin and into the subarachnoid space where the CSF is located. You will feel some pressure while the needle is inserted. You must remain absolutely still during the insertion of the needle.
8. The CSF will begin to drip out of the needle and a small amount, about one tablespoon, will be collected into test tubes.
9. If the physician needs to inject medication into the spinal canal, it will be given through the same needle after the CSF is collected.
10. When the procedure is completed, the needle will be removed and an adhesive bandage will be placed over the injection site. The test tubes will be taken to the laboratory for analysis.
11. You should notify the physician if you feel any numbness, tingling, headache, or lightheadedness during the procedure.

You may experience discomfort during a lumbar puncture. The physician will use all possible comfort measures and complete the procedure as quickly as possible to minimize any discomfort or pain.

After the Procedure

You will be asked to lie flat for up to eight hours after the lumbar puncture is completed. This helps reduce the incidence of a headache. You will be allowed to roll from side to side as long as your head is not elevated. You may be asked to urinate in a bedpan during the time that you are required to stay flat.

You will be asked to drink additional fluids to rehydrate after the procedure. This replaces the CSF that was withdrawn during the spinal tap and reduces the chance of developing a headache.

When you have completed the recovery period, you may be taken to your hospital room (if the procedure was performed elsewhere in the hospital) or discharged to your home.

Once you are at home, notify your physician of any abnormalities, such as numbness and tingling of the legs, drainage of blood or pain at the injection site, inability to urinate, or headaches. If the headaches persist for more than a few hours after the procedure, or when you change positions, you should contact your physician.

You may be instructed to limit your activity for 24 hours following the procedure. Generally, if no complications occur, you may return to your normal diet and activities.

Your physician may give you additional or alternate instructions after the procedure, depending on your particular situation.

Online Resources

The content provided here is for informational purposes only, and was not designed to diagnose or treat a health problem or disease, or replace the professional medical advice you receive from your physician. Please consult your physician with any questions or concerns you may have regarding your condition.

This page contains links to other Web sites with information about this procedure and related health conditions. We hope you find these sites helpful, but please remember we do not control or endorse the information presented on these Web sites, nor do these sites endorse the information contained here.

American Academy of Neurological and Orthopaedic Surgeons

American Academy of Orthopedic Surgeons

National Cancer Institute

National Institute for Neurological Disorders and Stroke

National Institutes of Health (NIH)

National Library of Medicine

Spinal Tap

http://www.emedicinehealth.com/spinal_tap/article_em.htm



Spinal Tap Introduction

• A spinal tap is a procedure performed when a doctor needs to look at the cerebrospinal fluid (also known as spinal fluid). Spinal tap is also referred to as a lumbar puncture, or LP.
  
  
• Some of the reasons your doctor may want to do a spinal tap include the following:
  
  
  • To look for infection
    
    
  • To check to see if there is bleeding around the brain (subarachnoid hemorrhage)
    
    
  • To look for causes of unexplained seizures
    
    
  • To look for causes of headaches
  
  
• Cerebrospinal fluid is a liquid that bathes the brain and spinal cord. An adult has about 140 mL (just under 5 oz) of spinal fluid. Typically, an adult makes 30-100 mL of spinal fluid daily.
  
  
• A spinal tap can be performed in any person and at any age from newborn to age 100 years and older.

Risks

Although infrequent, several complications can occur as a result of a spinal tap.

• Headache
  
  
  • About 5-30% of people who have a spinal tap get what is commonly referred to as post –lumbar puncture headache.
    
    
  • Your headache may start up to 48 hours after the procedure and usually lasts for 2 days or less.
    
    
  • The headache typically worsens when you are in an upright position and lessens when you lie flat.
    
    
  • The cause of the headache is leakage of the spinal fluid from around the puncture site.
    
    
  • Younger people and males have an increased risk of headaches after lumbar puncture compared with older people and females.
    
    
  • You reduce your chance of getting one of these headaches by drinking plenty of fluids, especially caffeine products such as tea, coffee, and cola.
    
    
  • Occasionally, a blood patch is needed. An anesthesiologist or pain management specialist injects a small amount of your own blood at the site where the spinal tap was performed. You usually experience relief within 30 minutes after this procedure.
  
  
• Herniation
  
  
  • A herniation can occur if an abscess (pocket of infection) or increased intracranial pressure (ICP) is present during your spinal tap.
    
    
  • If the pressure in your brain is elevated when the spinal tap is performed, the flow of fluid from the brain down the cord may cause the brain to get squeezed down into the direction of the spinal cord. This is extremely rare and occurs only with elevated intracranial pressure.
    
    
  • If a person has signs and symptoms consistent with meningitis (fever, headache, and stiff neck), then the spinal tap may be performed immediately. In some people, a CT scan of the brain is performed first, however, to rule out the possibility of bleeding or other causes that may increase the pressure within the skull or around the brain.
    
    
  • If increased intracranial pressure is suspected, great caution is taken and your condition is carefully discussed before a spinal tap is performed, if it is performed at all.
  
  
• Bleeding
  
  
  • Injury to the blood vessels that surround the covering of the spinal canal may occur when the needle is being inserted. Frequently referred to as a traumatic tap, this may cause a small amount of localized bleeding.
    
    
  • Sometimes this can affect the results of the procedure, which would mean that the doctor would have to re-insert the needle into another area of the back, frequently an inch or so away from the first site. Proper numbing medicine, if needed, is injected to decrease any pain.
    
    
  • The spinal cord ends at the level of the first or second lumbar vertebrae, and the needle is usually inserted at a level between the third and fourth or the fourth and fifth lumbar vertebrae, keeping the spinal cord completely out of danger.
  
  
• Epidermoid cyst
  
  
  • Rarely, certain tissues (epidermoid) are accidentally implanted into the spinal canal when the spinal tap is performed.
    
    
  • The likelihood of an epidermoid cyst is much greater when a needle without a stylet is used, and this almost never occurs today. All spinal tap kits used today have needles with stylets.

Spinal Tap Preparation

• No special preparation is needed on your part before a spinal tap.

• Always ask your doctor to fully explain the process to you as she or he is doing it. This talking through helps to lessen any anxiety that you may experience.

During the Procedure

Most spinal taps can be completed within 5-10 minutes.

• You are asked to lie on your side with your legs and hips bent (flexed) up toward your chest and your neck slightly bent forward. This position is often called the fetal position. (Some doctors place you in a seated position, where you lean forward and rest your arms on a tray or back of a chair. This is an acceptable alternative position.)

• The doctor always wears sterile gloves and occasionally also wears a mask and gown.

• The spinal tap is performed using sterile technique, meaning that everything used is sterilized to minimize any risk of infection.

• The doctor next identifies landmarks on your body. Frequently, the doctor does this by feeling the top of the pelvis bone (on your side). This area corresponds with the fourth and fifth lumbar space where the needle is inserted.

• A numbing medication (lidocaine) is injected first into your skin and then into the deeper tissues of your lower back to numb the area completely. This injection causes some minor discomfort, which is usually brief and has been described as a burning sensation.

• You should inform the doctor at any time if you feel pain when the procedure is being performed.

• The needle is then inserted in your lower back, usually at the third and fourth lumbar or fourth and fifth lumbar level. The needle passes between the 2 vertebrae to enter the space where the fluid is contained. Placing you in the fetal position allows the vertebral spaces to open more widely to make needle passage easier.

• Occasionally, the doctor may measure the pressure within the fluid containing area. This does not change the procedure nor does it affect the results.

• The fluid is then allowed to collect into a series of 3 or 4 vials that are then sent to the lab for evaluation.

• The fluid collects passively, meaning it is allowed to drip out into each vial at its own pace. This step can take several minutes for a full specimen collection.
  
  
• After the fluid is collected, the needle is removed and a bandage or small dressing is placed over the area.

After the Procedure

• You may be asked to lie flat on your back for a time after the spinal tap. This is to reduce the possibility of headaches. Drinking fluids, especially caffeine products such as tea, coffee, and cola can also help to reduce headaches.

• Your puncture site may be sore for 1-2 days.

• As with any procedure where the skin is punctured, the area should be monitored for signs of infection. Redness, swelling, pus from the area, or tenderness to touch should prompt immediate attention from a doctor.

Next Steps

• Depending on the reason for the spinal tap, follow-up care may or may not be necessary.

• If the tap is performed in the emergency department, then you are frequently instructed to follow up in 24-48 hours, either with your doctor or in the emergency department.

• If the spinal tap is performed in a doctor’s office, then a follow-up telephone call may be suggested, or a follow-up appointment may be scheduled to discuss the results of the tests, especially if specialized testing is ordered.

When to Seek Medical Care

You should contact your doctor if any of the following occur:

• Infection

• Rarely, infection at the site where the needle was inserted may occur.
  
  
• Signs and symptoms include redness, swelling, tenderness, or pus from the site.

• Headache

• Headaches can occur after a spinal tap and occasionally may be severe.
  
  
• If this occurs, you should contact your doctor.

Any signs or symptoms of infection or severe headache should prompt immediate attention from your doctor. If you are unable to reach your doctor, then you should seek immediate attention from your local emergency department.

Multimedia

Media file 1: The lower portion of the back, or lumbar region. The doctor is pointing to the area where the needle will be inserted between the third and fourth vertebrae. Notice the other hand on the top of the pelvis bone serving to help locate this area. (For orientation purposes, the patient is on the right side with the head off to the right side of the screen.)

Media type: Photo

Media file 2: An example of the sterile technique used. A drape is placed around the area (the blue sheet), and then the needle is put in place. (The glass tube going up from the needle is the device used to measure the pressure of the fluid itself.)


Media type: Photo

Media file 3: The fluid is allowed to collect into each of the vials so that it can be sent to the lab for analysis.


Media type: Photo

Synonyms and Keywords

spinal tap, lumbar puncture, spinal puncture, cerebrospinal fluid analysis, LP

References

1. Cooper JR. Routine use of CT prior to lumbar puncture. Br J Radiol. Mar 1999;72(855):319. [Medline].

2. Gonzalez DP. Lumbar puncture headache exacerbated by recumbent position. Mil Med. Sep 2000;165(9):vi, 690. [Medline].

3. Greenhall R. Lumbar puncture. Br Med J. Mar 15 1980;280(6216):796. [Medline].

4. Kooiker JC, Roberts JR, Hedges JR. Spinal puncture and cerebrospinal fluid examination. In: Clinical Procedures in Emergency Medicine. 2^nd ed. 1991:969-84.

5. Linden CH, James WA, Hartigan CF. Cranial computed tomography before lumbar puncture. Arch Intern Med. Oct 9 2000;160(18):2868-70. [Medline].

6. Schull M, Tintinalli JE. Headache and facial pain. In: Emergency Medicine: A Comprehensive Study Guide. 5^th ed. 2000:1429.

7. Tattevin P, Bruneel F, Régnier B. Cranial CT before lumbar puncture in suspected meningitis. N Engl J Med. Apr 18 2002;346(16):1248-51; author reply 1248-51. [Medline].

8. Thomas SR, Jamieson DR, Muir KW. Randomised controlled trial of atraumatic versus standard needles for diagnostic lumbar puncture. BMJ. Oct 21 2000;321(7267):986-90. [Medline].

9. Vallejo MC, Mandell GL, Sabo DP, Ramanathan S. Postdural puncture headache: a randomized comparison of five spinal needles in obstetric patients. Anesth Analg. Oct 2000;91(4):916-20. [Medline].

Authors and Editors

Author: Scott D Fell, DO, FAAEM, Medical Director, Emergency Care Center, Bon Secours Venice Hospital.

Coauthor(s): Christina L Kukula, DO, Consulting Staff, Walk-in-Care Center, Bon Secours Venice Hospital.

Editors: Scott H Plantz, MD, FAAEM, Research Director, Assistant Professor, Department of Emergency Medicine, Mount Sinai School of Medicine; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Thomas Rebbecchi, MD, FAAEM, Program Director, Assistant Professor, Department of Emergency Medicine, University of Medicine and Dentistry of New Jersey.

Last Editorial Review: 10/20/2005