Symptoms of brain nerve injury in children are divided into the following five aspects: 1, abnormal muscle tone: body tenderness and reduced voluntary movement is a manifestation of hypotonia, limb stiffness is a symptom of hypertonia, muscle tone abnormalities can be seen at 1 month; 2, there are obvious abnormal posture: often due to brain injury so that muscle tone abnormalities, such as angular arch, frog position, inverted U-shaped posture, etc., in the first month of life 3, abnormal head circumference: head circumference is an objective indicator of the morphological development of the brain, brain injury and often have abnormal head circumference, normal head circumference is 34-36 cm after birth, 1-6 months growth of 8-10 cm, 6-12 months growth of 2-4 cm, 6 months to 44 cm, 1 year old head circumference is 46 cm, 2 years old head circumference is 48 cm, 5 years old head circumference is 50 cm, 15 years old Close to adult head circumference is 54-58 cm; 4, there is a significant motor development lag: normal motor development is more than 1 month children will appear to chase after hearing, chase after seeing, 3 months will erect head, 4 months will roll over, 6 months will sit, 8 months will crawl, 1 year and 2 months will walk; 5, appear low weight and breastfeeding difficulties: brain injury children’s weight is often lower than normal children; 6, appear strabismus: 3-4 months of Infants with strabismus and poor eye movement can also suggest the presence of brain injury.