An EEG is required to diagnose epilepsy. If the patient has never been diagnosed with epilepsy before and it is the first time he or she has a seizure, he or she should go for an EEG as soon as possible to diagnose whether it is epilepsy or whether the seizure is due to some other cause. If it is diagnosed as epilepsy, it needs to be treated as early as possible to prevent further seizures that could cause danger to the patient. Patients who usually take medication for a long time usually need to have their EEG reviewed in the second half of the year, even if the patient has not had a seizure for a long time. The EEG is needed to see how much discharge the patient has, whether the discharge has changed, how the patient responds to the medication, and whether the patient can stop the medication after 2-5 years of no seizures.