Hydrocephalus is a common pediatric condition that results in enlarged ventricles, thinning of the cortex, and increased intracranial pressure due to excess cerebrospinal fluid volume. The incidence of congenital hydrocephalus is 0.9-1.8:1000, with an annual mortality rate of approximately 1%. Etiology and classification Hydrocephalus is classified according to the site of obstruction. If the site of obstruction is above the arachnoid granules, the ventricles above the site of obstruction are enlarged, in which case it is called obstructive hydrocephalus or non-traffic hydrocephalus. If the obstruction is at the level of the arachnoid granules, the absorption of cerebral fluid is impaired, the lateral ventricles, the third ventricle and the fourth ventricle are dilated, and the volume of cerebrospinal fluid in the subarachnoid space is increased, which is called non-obstructive hydrocephalus or traffic hydrocephalus. The clinical manifestations of hydrocephalus in infants are agitation, lethargy, growth retardation, apnea, bradycardia, hyperreflexia, increased muscle tone, progressive increase in head circumference, full fontanelle, cracked bones, thin scalp, varicose scalp veins, upper eyelids that cannot droop, impaired upward eye movement (also called sunset sign), decreased consciousness, optic papilla edema, optic nerve atrophy causing visual weakness or even blindness III, IV, VI pairs of cranial Nerve palsy, head raising, sitting, crawling, speaking, cognition of the outside world, and physical and intellectual development are lagging behind those of children of the same age. In children, because the cranial sutures are already closed, hydrocephalus can manifest as headaches (especially in the morning), nausea, vomiting, lethargy, optic papilloedema, decreased visual acuity, decreased cognitive function and behavior, memory impairment, decreased attention span, decreased academic performance, altered gait, inability to see upward, diplopia, and convulsions. In infants and children with hydrocephalus, motor deficits may manifest as spastic paralysis of the lower extremities, with mild symptoms of heel tension, foot drop, and in severe cases, increased muscle tone throughout the lower extremities and a spastic gait. Diagnosis Based on the typical symptoms and signs, it is not difficult to make the diagnosis of hydrocephalus. The medical history should pay attention to the mother’s pregnancy, the gestational age of the baby, whether forceps or fetal head suction has been used, any history of head trauma, and any history of infectious diseases. Head circumference measurement, ultrasound, cranial CT or MRI should be performed. Treatment The aim of treatment is to obtain ideal neurological function and to prevent or restore neurological damage caused by ventricular enlargement compressing brain tissue. Treatment: cerebrospinal fluid shunt surgery and neuroendoscopic triple ventriculostomy. The main common complications of shunt surgery: shunt obstruction and infection, excessive shunting (subdural blood accumulation, hypocranial pressure syndrome, ventricular fissure syndrome), and isolated fourth ventricular dilatation.