Wash your hair the night before the test. Do not use conditioner, oils, sprays, or gel on your hair. If you have a hair weave, ask your doctor or nurse for special instructions.
Your health care provider may want you to stop taking certain medicines before the test. Do not change or stop taking any medicines without first talking to your health care provider. Bring a list of your medicines with you.
Avoid all food and drinks containing caffeine for 8 hours before the test.
You may need to sleep during the test. If so, you may be asked to reduce your sleep time the night before. If you are asked to sleep as little as possible before the test, do not eat or drink any caffeine, energy drinks, or other products that help you stay awake.
Follow any other specific instructions you are given.