Why Is a Spinal Tap 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 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 (called the meninges). The CSF contains glucose (sugar), proteins, and other substances found in the blood. When the CSF is examined in the lab, 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 drug.
