It is common knowledge that acupuncture treatment needs to find the right acupuncture point, and tooth extraction needs to determine which tooth has a problem. By extension, for any disease to be treated surgically, the location of the lesion has to be found, which is called positioning. Kidney stones can be localized with ultrasound, but ultrasound cannot be used for brain tumors because it cannot penetrate the thick skull. Some lesions are very easy to locate, like orchitis, commonly called appendicitis. The most difficult part is the localization of intracranial epileptic foci in epileptic patients. First of all, epilepsy is not a surgical disease, which means that surgery is not the primary treatment for epilepsy. We already know that 70% to 80% of patients can have complete seizure control with regular medication, and 20% to 30% of patients have difficulty controlling their seizures with current medication. Why is it so prudent? If the epileptic foci are located in important functional areas of the brain, surgical treatment may add new diseases after treatment, making patients who could have gone to school partially paralyzed or unable to speak, which is called aphasia in medicine, or even a young girl who became a vegetable, all of which have happened. This has happened before. The difficulty in localizing epileptic foci is that the underlying pathophysiological changes in the epileptic foci are abnormal potentials in the neuronal membranes and there is no or no structural damage. Therefore, CT and MRI are not very useful in identifying epileptic foci. Some people may say that CT and MRI in epileptic patients reveal mild developmental abnormalities in the brain, a small cyst, or even a tumor. It should be emphasized that epilepsy is the result of abnormal neuronal discharge, and there is no professional book that states that tumors and cysts “discharge” to cause epilepsy, because they have no electrical activity and do not discharge. These lesions can affect the function of surrounding neurons and cause abnormal discharges leading to seizures. There are now more modern tests called single photon tomography (SPECT) and positron tomography (PET), which do detect changes in cerebral blood flow and metabolic changes in epileptic foci. However, these changes are not specific to epileptic foci, but can also be found in other diseases, such as cerebrovascular disease. It is also common to find abnormalities in these two tests that are not in the same place as the epileptic focus, or even in the opposite direction. Therefore, it is not possible to rely on these two tests alone for the localization of the epileptic focus. Since the basic abnormality of the epileptic focus is abnormal discharge, EEG is definitely the main basis for localization. However, conventional EEG cannot meet the requirement of accurate localization because the abnormal potentials from neurons to the electrodes on the scalp have to pass through the skull and scalp with high resistance, which makes the localization inaccurate, and secondly, because the recording time of conventional EEG is short and the abnormal potentials may not be recorded. -In order to find out where the abnormal discharges originate, careful analysis of seizure performance and EEG changes at the moment of seizure onset, during and after the seizure should be performed. A neuropsychological examination should also be performed to determine if the epileptic focus is located in an area of important neurological function. If the epileptic focus is in an important neurological area, such as speech and movement, then surgical treatment should never be done. The results of imaging, brain metabolism, blood flow changes, neurophysiological and neuropsychological examinations should be discussed by all the specialists to determine the location of the epileptic focus. It can never be determined by a simple visit to a neurosurgery clinic. Whether the surgery can completely eliminate the root cause of the disease, we will introduce the following in conjunction with the surgery method.