Health
Fact-checked

At WiseGEEK, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What is Cerebrospinal Fluid?

Emma Lloyd
Emma Lloyd

Cerebrospinal fluid is a clear fluid that surrounds the brain and provides the organ with protection and support. The fluid is produced and secreted by cells in the brain called ependymal cells. Certain infections and diseases can be diagnosed by testing samples of cerebrospinal fluid.

The fluid is produced in a central section of the brain called the choroid plexus. More than half of the choroid plexus is made up of ependymal cells, arranged in many layers of cells and blood vessels. The cells produce and secrete cerebrospinal fluid, and the fluid flows from the choroid plexus to circulate around the brain and spinal cord.

A medical manometer may be used to measure cerebrospinal fluid pressure.
A medical manometer may be used to measure cerebrospinal fluid pressure.

Cerebrospinal fluid has several functions. First, the fluid provides the brain with buoyancy, which allows the organ to support its own weight without collapsing. Without the fluid, the weight of the brain would prevent it from maintaining a constant blood supply to lower sections. The fluid also provides an important level of protection by acting as a mechanical buffer which prevents the brain and skull from coming into contact. Spinal fluid also helps remove metabolic waste from the brain and spinal cord. The fluid is constantly circulating around the brain and spinal cord, allowing waste to diffuse through the blood-brain barrier and be removed from the body.

Headache and radiating pain down the neck may occur after a spinal tap.
Headache and radiating pain down the neck may occur after a spinal tap.

Cerebrospinal fluid analysis is carried out to test the fluid for infection and other signs of disease. Healthy fluid is clear, but when bacterial infection is present, the fluid is cloudy and might contain blood. The types of proteins present or absent in the fluid also can provide diagnostic clues. Conditions that might require a spinal fluid analysis include encephalitis, epilepsy, hydrocephalus, meningitis and pituitary tumors.

A spinal fluid analysis may be required for individuals who are suffering from meningitis.
A spinal fluid analysis may be required for individuals who are suffering from meningitis.

The most common method for collecting the fluid is via a procedure called a lumbar puncture or spinal tap. The patient lies on his or her side with knees tucked toward the chest or sitting up in a bent-over position. The lower back is cleaned, and an anesthetic is injected into the spine. A fluid collection needle is then inserted into the lower back to collect a sample. After the sample is taken, the site is cleaned again and bandaged.

Cerebrospinal fluid is constantly circulating around the brain and spinal cord to help remove waste.
Cerebrospinal fluid is constantly circulating around the brain and spinal cord to help remove waste.

During this procedure, it is very important that the patient remain still while the fluid is being collected. This is because movement might cause the needle to move and injure the spinal cord. Careful cleaning of the area is important to prevent infection. In addition, the patient should rest for several hours following the procedure, in order to prevent any leakage of spinal fluid.

Discussion Comments

serenesurface

@ddljohn-- My sister had this done. It took her six weeks to get the results. The equipment needed to test spinal fluid isn't available at every lab, so don't be surprised if it takes a long time.

What they look for in the cerebrospinal fluid for diagnosis of autoimmune disorders, is antibodies. The same is true when there is an infection. When the body is fighting off infections, or fighting its own tissues due to an immune system disorder, it releases antibodies in the cerebrospinal fluid. They might look for some other substances as well, but I'm not sure what all of them are.

burcidi

@ddljohn-- The most important thing while cerebrospinal fluid collection or the injection of medications into it, is to stay very calm. Just relax and let the medical professionals do their job. If you get stressed out and react, they won't be able to do it properly.

I received epidural while delivering my son. Epidural is a pain reliever and it's injected into the spinal fluid. After they inject it, you have to sit upright so that the fluid doesn't go above your chest. It makes the lower half of the body go numb so that the mother doesn't feel pain while giving birth.

I didn't stress out during the injection at all. It didn't take very long, I felt a pinch during the injection but nothing after that. I was completely awake while delivering my baby and everything went well.

It is a risky procedure to inject medications into the cerebrospinal fluid, but it's also the fastest way to get medication into the system. And many disorders like yours wouldn't be diagnosed as easily if doctors didn't sample this fluid. As far as I know, it's also used to diagnose Alzheimer's, Jacob disease, leukemia and many more.

ddljohn

I will have a spinal tap test done in three weeks for testing of multiple sclerosis. I've had a lot of fatigue, stiffness in my muscles and blurry vision lately. My doctor said that these are some symptoms of multiple sclerosis but we won't know for sure until they test my cerebrospinal fluid.

I'm apprehensive about the test. I know that it's a very sensitive test and if something goes wrong it could be bad. I'm trying to stay positive and hope for the best.

Has anyone had a spinal tap test before? Do you know how long it will take to get the results back? And which substances do lab experts check for to differentiate between a normal cerebrospinal fluid and an abnormal one?

I was told that the results would be delivered directly to me, although they didn't tell me a time frame. It might be another week after I get the results until I can show them to my doctor. I'm wondering if I will be able to tell from the results myself if I have multiple sclerosis or not?

Post your comments
Login:
Forgot password?
Register:
    • A medical manometer may be used to measure cerebrospinal fluid pressure.
      By: Witold Krasowski
      A medical manometer may be used to measure cerebrospinal fluid pressure.
    • Headache and radiating pain down the neck may occur after a spinal tap.
      By: Photographee.eu
      Headache and radiating pain down the neck may occur after a spinal tap.
    • A spinal fluid analysis may be required for individuals who are suffering from meningitis.
      By: Klaus Eppele
      A spinal fluid analysis may be required for individuals who are suffering from meningitis.
    • Cerebrospinal fluid is constantly circulating around the brain and spinal cord to help remove waste.
      By: nerthuz
      Cerebrospinal fluid is constantly circulating around the brain and spinal cord to help remove waste.
    • A buildup of cerebrospinal fluid may cause pressure on the brain and severe headaches.
      By: BlueSkyImages
      A buildup of cerebrospinal fluid may cause pressure on the brain and severe headaches.
    • A stiff neck may be a sign of a buildup of cerebrospinal fluid.
      By: Laurin Rinder
      A stiff neck may be a sign of a buildup of cerebrospinal fluid.
    • Fever is a common symptom of meningitis.
      By: tab62
      Fever is a common symptom of meningitis.
    • An MRI scan may be conducted to diagnose hydrocephalus.
      By: Rob Byron
      An MRI scan may be conducted to diagnose hydrocephalus.