Widening of the extracerebral space is not necessarily a disease, do not over-treat. Many babies are diagnosed as “external hydrocephalus” after brain CT examination, parents are very stressed and keep running to major hospitals to do a lot of treatments for their children. In fact, many cases diagnosed as external hydrocephalus are actually widening of the extracerebral space, which is a normal physiological phenomenon. It is a normal physiological phenomenon. Widening of the extracerebral space within 6 months is a normal physiological developmental manifestation. The extracerebral space widens gradually from birth to 6 months of age and then narrows gradually. During the 6 months, as the central nervous system continues to myelinate, the frontal lobe belongs to the neocortex, which develops late and reduces the amount of water in the brain, the widening of the extracerebral space occurs, and it will gradually disappear after 6 months. Many people treat the widening of the extracerebral space as hydrocephalus and over-treat it, doing high R oxygen and nutritional injections, etc., causing unnecessary pain to the child, affecting the child’s growth and development and wasting resources.