Cerebrospinal Fluid Analysis
From Holoprosencephaly
Cerebrospinal Fluid Analysis (Spinal Tap)
This involves the removal of a small amount of the fluid that protects the brain and spinal cord. The fluid is tested to detect any bleeding or brain hemorrhage, diagnose infection to the brain and/or spinal cord, identify some cases of multiple sclerosis and other neurological conditions, and measure intracranial pressure. The procedure is usually done in a hospital. The sample of fluid is commonly removed by a procedure known as a lumbar puncture, or spinal tap. The patient is asked to either lie on one side, in a ball position with knees close to the chest, or lean forward while sitting on a table or bed. The doctor will locate a puncture site in the lower back, between two vertebrate, then clean the area and inject a local anesthetic. The patient may feel a slight stinging sensation from this injection. Once the anesthetic has taken effect, the doctor will insert a special needle into the spinal sac and remove a small amount of fluid (usually about three teaspoons) for testing. Most patients will feel a sensation of pressure only as the needle is inserted.
A common after-effect of a lumbar puncture is headache, which can be lessened by having the patient lie flat. Risk of nerve root injury or infection from the puncture can occur but it is rare. The entire procedure takes about 45 minutes.
