Want more iVillage? Sign up for our
Newsletters
A
lumbar puncture
(also called a spinal tap) is a procedure to collect and look
at the fluid (cerebrospinal fluid, or CSF) surrounding the brain and
spinal cord. Many different tests can be done on the CSF. Some results will be
ready right away, some will take a few hours after the procedure, and others
will take several weeks.
The normal values listed here—called a reference range—are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what’s normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.
Appearance: | CSF is normally clear and colorless. |
|---|---|
Pressure: | Normal CSF pressure in the lower back for an adult ranges from 90–180 millimeters (mm) water. For children younger than 8 years old, the normal opening pressure range is 10–100 mm water. |
Protein: | The normal protein content of CSF in an adult's lower back (lumbar) region is 15–45 milligrams per deciliter (mg/dL) or 150–450 milligrams per liter (mg/L). Older adults and children may have higher values that are still in the normal range. |
Glucose: | The normal range for glucose content in the CSF is about 60% of the blood glucose level. The levels may be slightly increased if the person has just eaten. |
Cell counts: | Normal CSF contains no red blood cells (RBCs). The white blood cell (WBC) count for adults is 0–5 WBCs per cubic millimeter (mm3). Children may normally have a higher WBC count. No neutrophils are present. The number of lymphocytes or monocytes is usually less than 1 per mm3. |
Other results: | No infectious organisms (such as bacteria, fungi, or a virus) are found in the CSF sample. No tumor cells are present. |
Appearance: | Blood in the CSF can result from bleeding (hemorrhage) in or around the spinal cord or brain, but it may also be caused by tiny blood vessel poked during the spinal tap. If a brain hemorrhage has occurred, the color of the CSF may change from red to yellow to brown over several days. Bleeding caused by the lumbar puncture itself will show more red blood cells in the first sample collected than in later samples. Cloudy CSF may mean an infection (such as meningitis or a brain abscess) is present. |
|---|---|
Pressure: | High CSF pressure may occur as a result of swelling (edema) or bleeding (hemorrhage) in the brain, infection (such as meningitis), stroke, or other circulatory problems. Below-normal pressure may mean a blocked spinal canal. |
Protein: | A high level of protein may be caused by bleeding in the CSF, a tumor or spread of a cancer from another area of the body, diabetes, infection, injury, Guillain-Barré syndrome, severe hypothyroidism, or other nerve diseases. An increase in antibodies (immunoglobulins) may be caused by inflammation in people who have multiple sclerosis, immune system disorders, or other bacterial and viral diseases. |
Glucose: | Low glucose levels in the CSF are abnormal and may be caused by bacterial meningitis. Viral meningitis does not often cause low glucose levels in the CSF. Brain hemorrhage may also cause low glucose levels several days after bleeding begins. Higher-than-normal glucose levels are often caused by diabetes. |
Cell counts: | Red blood cells (RBCs) in the CSF means bleeding. High levels of white blood cells (WBCs) mean meningitis. Tumor cells and abnormal levels of white blood cells mean cancer. |
Other results: | Antibodies, bacteria, or other organisms in the CSF means that an infection (such as syphilis) or disease is present. Bacterial markers (bacterial antigens) that show up mean meningitis. Cultures or stains of the CSF may also help show the cause of meningitis or encephalitis. |
Your doctor may order other special tests on the CSF fluid depending on your symptoms and past health.
| By: | Healthwise Staff | Last Revised: August 25, 2010 |
| Medical Review: | E. Gregory Thompson, MD - Internal Medicine Joseph O'Donnell, MD - Hematology, Oncology | |
© 1995-2011 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated. This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.
Welcome to Care Circle, an exclusive tool to help you take care of yourself and your loved ones. Here's how it works:
The information you input is strictly private; you choose who has access to your Care Circle.
How do I add myself or someone else to my care circle?
Click on "Add someone." Fill out the short profile. Choose an avatar. Select the topics and conditions that interest this person from the pulldown menu. You can select as many as you want, but you must choose at least one. Click on "Add Someone" again. You should start getting updates immediately.
How do I save content to my Care Circle?
Click on "Manage My Care Circle." Select the tab of the person for whom you're saving content. Put your cursor over the piece of content that you want to save; a disk icon will appear in the righthand corner. Click on the disk and the piece of content will be moved to a save folder.
How do I add additional topics and conditions for someone in my Care Circle?
Click on "Manage My Care Circle." Select the tab for the person whose preferences you'd like to update. Under "Add More to Follow," select additional topics and conditions.
How do I delete topics and conditions for someone in my Care Circle?
Click on "Manage My Care Circle." Select the tab for the person whose preferences you'd like to update. Under "Follows," scroll over the topic or condition you want to delete. An "X" should appear on the righthand side. Click on the "X" and the topic or condition will be deleted from the list.