Intracranial electrographic recording, especially stereoencephalography (SEEG), remains the gold standard for preoperative localization in epilepsy patients. However, this method is invasive and has low spatial resolution. In 1982, magnetoencephalography (MEG) began to be used in epilepsy clinics. MEG is not affected by the skull and scalp, can provide signals with high temporal and spatial resolution, and can be used to determine the epiletogensis zone (EZ) and the seizure onset zone (SOZ). Magnetic source imaging (MSI) is a method that superimposes the MEG data on a magnetic resonance image (MRI) and has become a major tool for presurgical localization. The applicability of MEG data has been largely improved by the development of many post-MRI processing methods in the last 20 years. In terms of the sensitivity of localization, MEG is superior to VEEG, MRI, PET and SPECT, despite inferiority to SEEG. MEG can also assist in the intracranial placement of electrodes and improve preoperative planning. Limitations of MEG include high cost, insensitivity to radiation source, and difficulty in locating deep EZ in the medial regions of the brain. These limitations could be overcome by new generations of equipment and improvement of algorithmics.
Drug-resistant epilepsy (DRE) not only have disruption of the patients by seizure, but also influence the quality of life, cognitive function and social association, as well as development delay even retrogression for children. Epilepsy surgery is the only curative treatment currently available for focal lesional pharmacoresistant epilepsy, five years complete seizure freedom rates was around 60% after surgery. The criterion of surgical intervention at present is achievement for the diagnosis of DRE, thereafter consideration of early epilepsy surgery, but these maybe a long-term duration. Recent advance in examine methods and surgical techniques have improved the surgical treatment of epilepsy, to such patient with focal lesional structure abnormality, before the DRE emergence, under the discussion of the multidisciplinary team. Children under 3 years old, the brain have greater neural plasticity, early surgical treatment is expected at allow the healthy brain to recover and develop the language function and quality of life. Numerous cause may pose abstracts to the delay of surgical intervention: (1) diagnosis delay; (2) patient himself and their familiar recognize that there have same risk of surgical treatment; (3) the primary doctor firmly believe that epilepsy surgery is the ultimate methods; (4) special problems of the patient, such including: age, comorbidity, and the location of symptom, EEG as well as imaging non-conformation.
Temporal lobe epilepsy (TLE) is the common type of drug resistent focal epilepsy. TLE not only have well known symptoms, but also have cognitive and language obstruction. It is accompanying with the advancement of neuroimage, We can noninvasive study the relationship between the function and brain structure. Direct cortical electrical stimulation contribute to investigation for several brain regions. TLE, especially left TLE, have abnormal cognitive and language function, Such as: naming function decline, Speech low fluency, verbal memory and visual cognitive dysfunction. However, up to now, all of these literatures were studied alphabetic language, Chinse language are ideographic language, the processing system in the brain should be different from alphabetic language.