Preparing for an EEG is straightforward: wash your hair the night before, skip styling products, eat a meal, and take your usual medications unless your doctor says otherwise. The test itself is painless and typically lasts 20 to 40 minutes. But the details matter, because anything that interferes with electrode contact or alters your brain’s normal electrical activity can compromise the results and potentially require a repeat test.
Hair and Scalp Prep the Night Before
Wash your hair the day before your EEG and let it dry completely. The key rule: no hairspray, mousse, gel, or oils on your scalp afterward. These products create a barrier between your skin and the electrodes, which need direct contact to pick up the tiny electrical signals your brain produces. Even a thin layer of residue can weaken the signal enough to make the recording unreliable.
Conditioner is worth skipping as well, since it leaves a coating on each strand that can cause the same problem. A simple shampoo wash is all you need. If you have extensions, braids, or a weave, call the testing facility ahead of time to ask whether any adjustments are necessary.
What to Eat and Drink
Eat a meal or at least a solid snack before your appointment. Low blood sugar can change your brain wave patterns and muddy the results, so arriving on an empty stomach works against you. A normal, balanced meal is fine.
Caffeine is the main thing to avoid. Coffee, tea, cola, chocolate, and energy drinks should all be off the table for at least eight hours before the test. Caffeine stimulates brain activity in ways that can mask or mimic the patterns your neurologist is looking for. If your EEG is scheduled for the morning, the simplest approach is to skip your morning coffee and have a caffeine-free breakfast instead.
Medications: Keep Taking Them
A common worry is whether you should stop your seizure medication or other prescriptions before the test. The standard guidance is to take your usual medications on the day of the EEG unless your doctor specifically tells you to do something different. Sedatives, muscle relaxants, sleeping pills, and anticonvulsants can all affect your brain’s electrical activity, so your doctor needs to know exactly what you’re taking. Mention every medication, including supplements and over-the-counter drugs, when you schedule the test or at check-in.
Sleep-Deprived EEG: Extra Steps
If your doctor ordered a sleep-deprived EEG, you’ll be asked to stay up most or all of the night before the test. The goal is to make it easier for you to fall asleep during the recording, since certain brain wave abnormalities only show up during sleep or in the transition between waking and sleeping.
For a sleep-deprived EEG, avoid all caffeine after midnight the night before. You’ll want someone else to drive you to and from the appointment, both for safety and because you’ll likely be exhausted. Try to stay awake naturally rather than relying on stimulants. Keeping lights on, moving around, and staying engaged with conversation or activities can help you push through the night.
Ambulatory (Multi-Day) EEG Prep
An ambulatory EEG records your brain activity over 24 hours or longer while you go about your normal routine at home. Preparation is slightly different because the electrodes and a small recording device stay attached to you the entire time.
Bathe and wash your hair thoroughly before your appointment. Your scalp needs to be completely clean and free of oils, conditioners, and sprays, because you won’t be able to shower or get the equipment wet during the monitoring period. Water will severely damage the recording unit.
Wear a button-down or zip-up shirt to your appointment. A pullover will knock electrodes out of position when you change clothes. You may also want to bring a hat or scarf to wear over the electrodes if you’re self-conscious about them in public. The electrodes are designed to handle normal perspiration and physical activity, so you can go about your day. The only real limitation is staying dry.
Preparing a Child for an EEG
If your child is having an EEG, the biggest challenge is usually keeping them calm and still. Talk to them beforehand about what will happen in age-appropriate terms: someone will put small sticky patches on their head, it won’t hurt, and they’ll need to lie still and try to relax.
Don’t let your child sleep in the car on the way to the appointment. The technician will likely need them to fall asleep for 10 to 15 minutes during the test, and a car nap can make that impossible. Bring along a favorite stuffed animal, blanket, or comfort item to help them settle. Children are not given sedation for a routine EEG, so they need to be able to relax on their own. For very young or restless children, the technologist may use a padded restraint board to help them stay still enough for accurate readings.
What Happens During the Test
A routine EEG takes 20 to 40 minutes once the electrodes are in place. The setup itself adds some time: a technician measures your head, marks positions with a pencil, and applies small electrodes to your scalp using a paste or adhesive. This part is tedious but not painful.
During the recording, you’ll lie in a comfortable position with your eyes closed. The technician may ask you to open and close your eyes, do simple math, read a short passage, breathe deeply for a few minutes, or look at a flashing light. Deep breathing can make some people feel lightheaded, which is normal and passes quickly. If you have certain types of epilepsy, deep breathing or flashing lights can occasionally trigger a seizure. The medical team is prepared for this and it’s part of what they’re testing for.
The electrodes only record signals. They don’t send any electricity into your brain, and you won’t feel any sensations from them.
Removing Electrode Paste Afterward
The technician will remove the electrodes after the test, but you’ll likely go home with some adhesive residue stuck in your hair. Getting it all out can take some effort, and different methods work better depending on your hair type and the type of glue used.
Start with the gentlest approach: rub conditioner or oil (olive oil, coconut oil, or baby oil all work) into the sticky areas and let it sit for 10 to 30 minutes. Then work through the spots with a fine-toothed comb and wash with a clarifying shampoo. Oils are especially good for children with sensitive skin.
If oil alone doesn’t do the job, acetone (nail polish remover) can dissolve stubborn adhesive. Apply it only to the glue spots, let it sit for a few minutes, and wash it out. Use it sparingly, since acetone can dry out and irritate your scalp. Test a small area first if you have sensitive skin. Some hair stylists also have experience removing medical adhesives and may be able to help if you’re struggling.
When to Expect Results
Your EEG recording is reviewed and interpreted by a neurologist, not the technician who performs the test. The technician won’t be able to give you results on the spot. Turnaround time varies by facility, but most people hear back within a few days to a week. Your referring doctor will discuss the findings with you and explain what, if anything, the recording showed about your brain’s electrical activity.