Made up of cell groups called the choroid plexus, cerebrospinal fluid (CSF) is a colorless fluid located around the brain and spinal cord. The body has about two-thirds of a cup of this fluid. The purpose of CSF is to provide cushioning in this area, eliminate waste products from brain cells, and transport nutrients. If you have an issue with your central nervous system (CNS), it may be because something is in your CSF that shouldn’t be there, such as a virus or infection, or because an infection that developed elsewhere has spread to the CSF. The only way to know for sure is with a cerebrospinal fluid culture.
Why a CSF Culture May Be Recommended
Bacteria, viruses, and fungi sometimes get into the central nervous system. While your body’s immune system can take care of some issues with these types of invaders, there are times when CSF could become infected as well. If this happens, your body will likely need some assistance from antibiotics and other treatments. A culture may be ordered to diagnose several CNS conditions, including:
- Bacterial or viral meningitis
- Fungal infections
- Brain and spinal cord damage
- Subarachnoid hemorrhage (bleeding around the brain)
- Lyme disease
- Multiple sclerosis
- Brain cell inflammation (encephalitis)
- Spinal cord inflammation (myelitis)
How a Cerebrospinal Fluid Culture Is Performed
Typically, a spinal tap or lumbar puncture is performed to collect a fluid sample for the CSF culture. It’s collected with a long, thin needle inserted between vertebrae after a local anesthetic is administered. The fluid is gathered in a collection vial, and it usually takes a few minutes to get a sufficient sample. The entire procedure takes about 45 minutes.
If it’s not possible to do a lumbar puncture due to an underlying condition or other risks, a sample may be collected from the occipital bone, located by the base of the brain. Another option is to drill a small hole into the skull, although this is rarely necessary. CSF pressure may also be checked to determine if lower than normal pressure is causing some of the experienced symptoms.
Analyzing the Sample
After the sample is collected, it’s taken to a lab and placed in dishes containing a culture medium. The dishes are monitored for signs of bacterial growth. If there is no abnormal growth or signs of certain biomarkers, the CSF sample is considered normal.
If the CSF culture comes back positive for infection, further testing may be done to get a better idea of what’s causing the infection and how far it may have spread to determine an appropriate treatment plan. Follow-up testing usually involves:
- Complete blood count
- Blood culture
- Image testing (CT scan, MRI)
A cerebrospinal fluid culture itself is perfectly safe, but there are certain risks associated with the lumbar puncture done to collect the sample. Some patients may experience headaches or mild discomfort during the procedure. Rare side effects include infection and nerve damage. Prior to having a sample collected, let your Beverly Hills spine surgeon know if you are on blood thinners or have a lower than normal platelet count (thrombocytopenia) so proper precautions can be taken.
If you are experiencing chronic pain near the top of your spine, you may need minimally invasive neck surgery. Beverly Hills patients can trust Dr. Hyun Bae to diagnose the source of their pain and help them find relief. Reach out to The Spine Institute today at 310-828-7757 to schedule an appointment.