Ambulatory EEG (AMB EEG) An Ambulatory EEG (Amb EEG) is a safe, painless test, which will record the electrical activity produced by your brain. An Amb EEG uses a digital recording system to record brain activity for 24-72 hours while you go about your daily routine.For example, if you have a seizure disorder, the EEG can show where abnormal activity in your brain comes from and can help distinguish between generalized or focal seizures. An EEG is of value for diagnosing epilepsy only if it detects patterns typical of epilepsy. … It can also be used to confirm brain death.The electrodes are connected with wires to an instrument that amplifies the brain waves and records them on computer equipment. Once the electrodes are in place, an EEG typically takes up to 60 minutes. Testing for certain conditions require you to sleep during the test.