My Child Needs a Lumbar Puncture, Now What?

If doctors suspect your child might have aromatic l-amino acid decarboxylase (AADC) deficiency, they may order a lumbar puncture to aid in a diagnosis. Here are some tips on what to expect with this procedure.

What is AADC deficiency?

AADC deficiency is a rare genetic disorder characterized by developmental delays, and symptoms that include muscle weakness and stiffness, and movement disorders. Mutations in the DDC gene, which lower the activity of the AADC enzyme, cause the disease. This enzyme plays an important role in producing neurotransmitters, or cell signaling molecules, in the brain such as dopamine and serotonin. Their deficiency leads to problems in the transmission of signals between nerve cells, and poor communication between the brain and the rest of the body.

What is a lumbar puncture?

Also known as a spinal tap, a lumbar puncture is a procedure where a clinician inserts a needle between two lumbar bones to extract a sample of cerebrospinal fluid. Lumbar bones are vertebrae of the lower spine, while cerebrospinal fluid is the fluid that surrounds the brain and spinal cord.

If your child’s doctor suspects AADC deficiency, he or she will order that the fluid sample be tested for specific metabolites and neurotransmitters. When the AADC enzyme is deficient, levels of dopamine, serotonin, norepinephrine, and epinephrine are significantly lower in the cerebrospinal fluid.

Steps to take before, during, and after a lumbar puncture

This roughly hour-long procedure is generally low risk. Still, here are some safety tips to consider before your child undergoes a puncture:

• Inform the healthcare team of any allergies your child may have.
• If needed, interpreting services can help you can communicate effectively for and about your child.
• Prepare and bring with you a list of medications your child has been taking. Your child should not take aspirin or aspirin-containing products for at least five days before the procedure. Talk with the doctor if your son or daughter takes a blood thinner, or a non-steroidal anti-inflammatory drug.

Preparing for the test

Here are some tips on how to prepare for the lumbar puncture:

• Arrive with your child about an hour before the scheduled exam time.
• Prepare any questions you may have, since you’ll have a chance to speak with the radiologist about planning for the test. This is also a good time to soothe and reassure your child, who will receive a local anesthetic to numb the lumbar area.
• Prior to the procedure, the doctor may advise you about food or drinks your child should or should not consume. Make sure to follow this advice.
• Bring with you any X-rays, computed tomography (CT) scans, or magnetic resonance imaging (MRI) scans of your child’s spine or brain.

During the procedure

During the procedure, the technologist will position your child on the exam table, being mindful of any muscle stiffness or other issue associated with AADC deficiency. Most patients will lie on their stomachs. Throughout the test, the technologist and radiologist will be available to answer any questions.

After the lumbar puncture

Following the procedure, your child will be brought to the radiology holding area for rest and observation. He or she will lie flat on their back for up to an hour to minimize the chance of headaches.

Here are a few things you could do after the procedure:

• Have your child drink extra fluids for the rest of the day.
• Because AADC deficiency can affect your child’s ability to speak, monitor him or her for symptoms such as fever, chills, any increase in back pain while at rest, difficulty moving their legs, or abnormal sensations in the legs. If you detect any of these, inform a nurse or doctor. If you’re very concerned, seek emergency help.
• You may remove the bandage covering the needle entry area after about 24 hours.

Last updated: Nov. 4, 2020

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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.