How to Prepare for a Lumbar Puncture in AADC Deficiency

Emily Malcolm, PhD avatar

by Emily Malcolm, PhD |

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lumbar punctures and CSF

If your child’s doctor suspects aromatic L-amino acid decarboxylase (AADC) deficiency, they may recommend a lumbar puncture (also called a spinal tap) to help diagnose the disease. Here is what to expect, and how to prepare for the procedure.

What happens during a lumbar puncture?

A lumbar puncture involves inserting a thin needle into the spinal cord, between the bones of the lower spine. These are called the lumbar vertebrae. The doctor uses the needle to collect a small quantity of cerebrospinal fluid (CSF), the fluid that surrounds and protects the brain and spinal cord. The CSF contains metabolites and neurotransmitters (important signaling molecules that allow nerve cells to communicate), which the doctor can use to diagnose AADC deficiency. The process takes about 30 minutes.

During the process, doctors often give patients an analgesic to ensure that they do not feel pain. Normally, they use a local anesthetic in the form of a cream or spray that numbs the injection site. However, children with AADC deficiency are very likely to be unable to hold still during the procedure. For this reason, your doctor may want to give them a general anesthetic so that they can sleep through the procedure. People with AADC deficiency may respond differently to some anesthetics, so if your child has never been given an anesthetic previously, make sure that you discuss a possible first use with your doctor and the anesthesiologist.

How do I prepare my child for a lumbar puncture?

There are no special preparations for a lumbar puncture. However, if your child will be under general anesthesia for the procedure, there may be special precautions to take. For example, your doctor will likely advise you to withhold food or drink for a given period of time before the procedure.

What happens after the lumbar puncture?

After the procedure, doctors will move your child to a recovery room and monitor them until they recover from the anesthesia.

It’s recommended that patients lie down for a few hours after a lumbar puncture, and drink plenty of fluids. Some patients may have a headache, which should subside a few hours after the procedure.

Are there any risks?

Although lumbar punctures are fairly routine, they do have some risks, including bleeding, and infection. Your doctor will discuss these risks with you prior to the procedure, and discuss how to best care for the injection site to reduce these risks.

When will I get the results of the test?

Some results will be available within 30 minutes to an hour. Others may take a few days. Your doctor will meet with you to discuss the results of the test, and to determine what the next step is for your child’s treatment.


Last updated: Aug. 12, 2020


AADC News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.