Lumbar Puncture (spinal tap): procedure that allows access to cerebrospinal fluid for testing or treatment.
A lumbar puncture is commonly called a spinal tap. This procedure allows a physician to examine the cerebrospinal fluid. Cerebrospinal fluid (CSF) is the fluid that surrounds the brain and spinal cord, and protects them from injury. CSF is most often collected from the lower back (the lumbar region); thus the name lumbar puncture or spinal tap. Here a needle is inserted between two bones of the spine (vertebrae) and a sample of CSF is removed.
A lumbar puncture can help diagnose serious infections, disorders of the central nervous system, or cancer of the brain or spinal cord. Sometimes doctors use lumbar puncture to inject medications or chemotherapy drugs into the cerebrospinal fluid.
The procedure can help a physician:
A lumbar puncture can also be used to help diagnose:
CSF Pressure: Decreased pressure may be the result of diabetic coma, shock, fainting or spinal canal blockage. Increased pressure may be the result of increased pressure within the skull.
CSF Appearance: CSF should be colorless and clear. A cloudy appearance can indicate the presence an infection, or an excess of protein or white blood cells in the CSF. A red appearance can indicate bleeding or a spinal cord obstruction. An orange or brown appearance may be a sign of prior bleeding.
Blood Cells in the CSF: Spinal fluid normally contains some white blood cells. However, increased numbers may indicate things like infection or the beginning of a chronic illness (e.g., multiple sclerosis). The presence of red blood cells may indicate bleeding into the spinal fluid (e.g., as result of a traumatic injury).
Presence of Foreign or Abnormal Cells: The presence of microorganisms can indicate an infection. And, the presence tumor cells or immature blood cells may indicate cancer.
strong Elevated levels of protein may be due to an infection, inflammation, tumor, diabetes, injury, or polyneuritis. Increased levels of specific immune system proteins may be due to diseases (e.g., multiple sclerosis, Guillain-Barre syndrome or syphilis). Decreased protein levels are a sign of rapid CSF production.
CSF Glucose Levels: Elevated glucose is a sign of high blood sugar. Low glucose levels may be due to low blood sugar or infection.