Gray matter heterotopia is a congenital abnormal developmental disorder of the central nervous system. During embryonic development, adult neuronal cells or undifferentiated cells do not migrate to the corresponding parts of the brain in time, but do not migrate or stay and accumulate between the ventricular canal and cerebral cortex, such as periventricular, white matter and subcortical areas, forming gray matter nodules of different sizes, which may be single or multiple, or sometimes diffuse. HGM mostly develops in adolescence with no significant difference in gender, and the age of onset varies from 1 to 20 years. The clinical manifestations of HGM mainly have 3 major features: 1. recurrent and frequent seizures 2. mental developmental disorders 3. neurological function deficits: such as hemiplegia due to damage of motor system and visual field disorders due to occipital HGM. The abnormal function of the nervous system is related to the thickness of the ectopic gray matter band. More than 80% of HGM patients have seizures as their first symptom, and most of them are drug-refractory epilepsy, and the seizure form has a tendency to be complicated as the duration of epilepsy lengthens. Surgical treatment: 1. Preoperative evaluation Localization of epileptogenic zone: Seizures caused by nodular HGM isolated in the white matter are mostly associated with this nodule. Combined with EEG examination and clinical manifestations of patients, the epileptogenic zone can be clarified; for seizures caused by disseminated or banded HGM, it is more difficult to precisely locate the epileptogenic zone, and intracranial electrodes need to be placed to determine the epileptogenic zone on the basis of non-invasive evaluation. For HGM in deep white matter or functional area, the tissue can be precisely removed under the guidance of navigation technology or stereotactic technology; for epileptogenic HGM in functional area, arousal surgery can also be performed, and the patient can be instructed to cooperate with related movements while operating in order to protect the important functional area of the brain to the maximum extent.