MRI in 6-year-old children is fine but EEG slow wave is usually due to dysplasia, encephalitis, epilepsy and other reasons. 1. Central nervous system dysplasia: head MRI mainly detects the structure of the brain, and dysplasia will not affect the results of MRI, while dysplasia patients will have insufficient cerebral cortex arousal, cerebral cortex is not mature enough and so on, which will lead to the slowing down of the electroencephalogram (EEG), and there will be a situation that the magnetic resonance of a 6 year old child is fine but the EEG is slow wave. 2. Encephalitis: If the patient has a cold, he will have pain, cough and other symptoms, which are usually not detected by MRI. The cold may lead to viral meningitis, viral encephalitis, etc., which will lead to slow EEG, resulting in the situation of 6-year-old children’s MRI is fine but EEG is slow wave. 3. Epilepsy: epilepsy is usually caused by abnormal neuronal discharge, which will lead to convulsions, spasms and other symptoms, usually not detected by MRI, epileptic EEG manifests diffuse slow wave, focal slow wave, triphasic wave, etc., resulting in 6-year-old children MRI is fine but EEG slow wave situation. There may be other reasons for the 6-year-old child’s MRI to be fine but the EEG to be slow wave. It is recommended to go to the hospital in time, complete the examination to clarify the cause of the disease, and then give targeted treatment or therapy under the guidance of the doctor.