spinal tap
Meaning of spinal tap: A spinal tap withdraws cerebrospinal fluid from the lower back using a thin needle, either to test the fluid or to deliver medication.
Definition of spinal tap
A spinal tap is a procedure in which a thin needle is inserted into the lower part of the spinal canal, below the point where the spinal cord itself ends, to collect a sample of cerebrospinal fluid, the fluid that surrounds and cushions the brain and spinal cord.
The fluid obtained is examined for signs of infection, bleeding, or other abnormalities that can help diagnose certain neurological or infectious conditions. A spinal tap can also be used to measure the pressure of the cerebrospinal fluid or to deliver medication directly into the fluid, such as certain anesthetics or chemotherapy drugs.
A spinal tap is also called a lumbar puncture, since it is performed in the lumbar, or lower back, region of the spine specifically because the spinal cord does not extend that far down, reducing the risk of injuring it during the procedure.
Also known as
Used in a sentence
A spinal tap was performed to obtain cerebrospinal fluid for analysis after the patient developed a severe headache and fever.
Good to know
A spinal tap is performed low enough in the back that the needle passes below the spinal cord itself, a deliberate positioning that reduces the risk of injury to the cord during the procedure.