Separation anxiety in children occurs before the age of six and refers to excessive anxiety about leaving the person to whom the child is attached, excessive worry about the possibility of harm to the primary attachment or fear that they will not return; fear of separation from the primary attachment; reluctance or refusal to go to kindergarten or school (not because of kindergarten or school) because of fear of separation; reluctance or refusal to go to bed without the primary attachment; persistent and When separation from an attachment is expected, excessive and recurrent distress will appear immediately, which can be manifested as crying, tantrums, pain, indifference or withdrawal; some children will have recurrent somatic symptoms after separation: nausea, vomiting, headache, stomachache, malaise, etc. 1. Clinical manifestations For separation anxiety disorder, pediatricians should view the disorder from a developmental process perspective. Normal separation anxiety occurs as early as 6 to 8 months of age, and disappears after 3 years of age when the child understands that separation from the person to whom he or she is attached is temporary. Therefore, this disorder should be diagnosed with caution in children before 5 years of age, and not in children before 30 months of age. Separation anxiety disorder manifests itself in children who are deeply disturbed when they are separated from their relatives and have obvious anxiety. Most children often have unfounded fears that their relatives will leave them and have dangerous or unexpected accidents, so they do not want to leave their relatives and do not go to kindergarten or refuse to go to school, Some children will also have symptoms of autonomic nervous system dysfunction, vomiting, abdominal pain, headache, etc. The course of the disease lasts for months to years. 2, cranial CT examination Cranial CT examination is a method of examining the cranial brain through CT. It can clearly show the anatomical relationship between different cross-sections of the skull and the specific brain tissue structure. Thus, it greatly improves the detection rate of lesions and the accuracy of diagnosis. In general, CT has better visualization of human hard tissues than soft tissues. CT cranial examination is important for the diagnosis of most diseases in the skull, skull and scalp (including trauma, tumor, inflammation, vascular lesions, poisoning, degenerative and metabolic diseases, etc.). 3.Cranial ultrasound examination (1) B-type ultrasound cranial examination method is mainly used for children within 2 years of age whose fontanelles are not closed, through the fontanelles as a “sound window” for scanning. (2) Transcranial color Doppler imaging Through the temporal window, occipital window, orbital window, the cerebral arteries can be detected, and the flow velocity, frequency width, abnormal flow direction or audio abnormality of intracranial vessels can be determined, which is used for the diagnosis and etiological classification of cerebrovascular diseases.