Preparing for an accurate recording
An electroencephalogram (EEG) records the brain's electrical activity through electrodes placed on the scalp. For a clear recording, the electrodes need good contact with the skin, so the client washes his hair the night before and uses no oils, sprays, or conditioners, which form a barrier. He also eats breakfast as usual, because hypoglycemia from fasting alters brain electrical activity and can distort the recording. Clean, oil-free hair and a normal breakfast both prepare him for an accurate EEG.
Other preparation rules
Caffeine from coffee, tea, cola, or chocolate is usually avoided before the test because stimulants alter the recording. Antiseizure drugs are not stopped unless the provider specifically orders it; sudden withdrawal, especially of a drug such as phenytoin, can trigger severe seizures or status epilepticus. If sleep deprivation is ordered to increase the chance of capturing abnormal activity, the client receives specific instructions. The client is also reassured that the test is painless and does not deliver electricity to the brain.
| Plan | Hair | Breakfast | Medicine | Correct? |
|---|
| Option 1 | Washed, no oil | As usual | Not mentioned (continued) | Yes |
| Option 2 | Washed, no oil | Extra coffee | — | No: caffeine alters recording |
| Option 3 | Washed, no oil | Skipped | — | No: hypoglycemia alters recording |
| Option 4 | — | As usual | Skip phenytoin | No: withdrawal risk |
Why the other plans fail
Each wrong option contains one correct element combined with one error. Extra coffee at breakfast adds caffeine, which changes the recording. Skipping breakfast risks hypoglycemia, especially since he has been eating poorly for a month. Skipping the morning phenytoin dose without an order could provoke seizures, and he has already had breakthrough seizures. Watch out! In questions with combined instructions, check every part of each option; only one plan meets every rule.
Exam takeaway
EEG preparation: wash hair the night before without oils or sprays, eat normally, avoid caffeine, continue antiseizure drugs unless ordered otherwise, and follow any sleep instructions. Key point! Fasting and caffeine both distort the EEG, and antiseizure drugs are not stopped without an order.