The procedure is a lumbar puncture (spinal tap). Before the procedure, you will be asked to review the risks and sign a consent form. After the lumbar puncture is done, you will be asked to remain lying down flat for 6 hours.

Infants and children:
The preparation you can provide for this test depends on your child's age, previous experiences, and level of trust. For general information regarding how you can prepare your child, see the following:

• Infant test or procedure preparation (birth to 1 year)
• Toddler test or procedure preparation (1 to 3 years)
• Preschooler test or procedure preparation (3 to 6 years)
• Schoolage test or procedure preparation (6 to 12 years)
• Adolescent test or procedure preparation (12 to 18 years)

You will be asked to lie on your side in the fetal position with your legs curled towards your chest. The area where the needle will be inserted (in your lower back) will be thoroughly cleaned. The scrub will feel cold and wet.

You will then receive an injection at the site with local anesthesia which may sting or burn when first injected. There will be a hard pressure sensation when the needle is inserted, and there is usually some brief pain as the needle goes through. This pain should stop in a few seconds.

Overall, discomfort is mild to moderate. The entire procedure usually takes about 30 minutes but may take longer. The actual fluid collection only takes a few minutes.

• Risks of lumbar puncture include:
  • Hypersensitivity (allergic) reaction to the anesthetic
  • Discomfort during the test
  • Headache after the test
  • Bleeding into the spinal canal
  • Brain herniation (if performed on a person with increased intracranial pressure) which may result in brain damage or death
  • Damage to the spinal cord or nerve roots