In addition to some of the tests mentioned in Chapter 1, there are the following tests that can be applied, but not all of them are done. EEG and MRI are the 2 tests that must be done. PET (positronemissiontomography):is a nuclear medicine imaging technique. About 60％ of frontal lobe epilepsies and 70％ of interictal PET in frontal lobe epilepsies are hypometabolic. PET is a guide for localizing epileptic foci and can also help determine the site of intracranial electrode placement, but the site of PET hypometabolism is not necessarily an epileptic focus. MEG (magnetoencephalography): With high temporal-spatial resolution, it can detect epileptic foci less than 3 mm in diameter, and the accuracy of localizing epileptic foci is around 50-70％. MEG is also used to localize functional areas. Wadatest:The relationship between the epileptic focus and language function was determined by cerebral angiography with internal carotid artery injection of sodium isopentyl phenobarbital to localize the lateralization of language and whether the functional area of language was in the left or right hemisphere. Intraoperative arousal cortical electrical stimulation: After the patient is awakened from general anesthesia intraoperatively, the cortical layer is stimulated by a tiny electric current to induce seizures and localize the epileptic focus. It is also used to localize functional areas. Intraoperative cortical EEG: Through the intraoperative state of superficial anesthesia, electrode pads are directly contacted with the cerebral cortex to monitor seizure waves and identify epileptic focus. However, the monitored epileptic waves are intermittent discharges, and it is controversial how significant they are for localization of epileptic foci. In conclusion, the localization of epileptic foci depends on a variety of tools, both noninvasive and invasive tests. If noninvasive tests can localize the epileptic focus, invasive tests are not needed. 1-2 tests can localize the epileptic focus, more tests are not needed.