Spinal Tap (Lumbar Puncture)

What is a spinal tap (lumbar puncture)?

A spinal tap, also called a lumbar puncture, is a procedure used to obtain spinal fluid. The withdrawn spinal fluid is tested for infection (meningitis) or, occasionally, used to evaluate the cells, protein, or pressure of the spinal fluid.

When is a spinal tap used?

A spinal tap is used when there is concern about diseases or infections involving the brain.

How is a spinal tap performed?

The patient is positioned lying on their side or sitting up in bed. The doctor uses a numbing medicine (local anesthetic) on the lower part the back and then carefully inserts a needle into the spinal canal, which contains the spinal fluid. Approximately two teaspoons of spinal fluid are obtained and tested.

Does a spinal tap hurt?

When the needle is inserted the patient may sense some temporary discomfort or feel light pain that travels down one of the legs.

Are there any potential complications associated with a spinal tap?

The most common side effect of a spinal tap is headache. Other complications of a spinal tap are rare.