Clinically, we often hear doctors say normal intracranial pressure hydrocephalus, so what is normal intracranial pressure hydrocephalus? Normal intracranial pressure hydrocephalus is a clinicopathological syndrome, which means a kind of traffic hydrocephalus with intracranial pressure in the normal range and belongs to a state of chronic hydrocephalus, but also includes some incomplete obstructive hydrocephalus, such as midbrain conduit adhesions, stenosis and posterior cranial fossa adhesions. It is characterized by the cerebrospinal fluid pressure has returned to the normal range, but there is a significant enlargement of the ventricles, and the production and absorption of cerebrospinal fluid have been in a relative equilibrium state with the development of the disease. However, in practice it is still mostly in a state of intermittent high cranial pressure hydrocephalus, with intracranial pressure fluctuating from time to time during the course of the disease, either worsening or relieving. Normal pressure hydrocephalus can also occur in children, resulting in progressive enlargement of the ventricles and progressive damage to the white matter of the brain, but generally without signs of cranial hypertension, and in the later stages of the disease, compensatory hydrocephalus occurs and the ventricles stop enlarging. The classic clinical manifestations are dementia, gait disorders and urinary and fecal incontinence, but many patients have only one clinical manifestation, and this disease should be considered in the differential diagnosis of some patients. Intellectual changes are more common and usually appear first, but sometimes gait abnormalities are seen first. Intellectual changes are mainly characterized by slow reactions, impaired recent memory, sluggishness, fatigue, and apathy, with further diminished thinking skills, decreased computational ability, and personality changes. Mild gait abnormalities are characterized by slow and unsteady walking and broadening of the gait base, but there are no obvious cerebellar signs. In severe cases, there are difficulties in walking, standing and rising, and in advanced cases, they are bedridden. Motor deficits of the lower extremities are more severe than those of the upper extremities, manifesting as incomplete conus fasciculus damage, often with hyperactive tendon reflexes and positive pathological signs. Urinary incontinence appears relatively late and varies in degree. The basic pathogenesis of normal cranial pressure hydrocephalus is the obstruction of the cerebrospinal fluid circulation pathway and the accumulation of cerebrospinal fluid in the ventricular system. In theory, shunt surgery will have some clinical effect. Currently, lateral ventriculoperitoneal shunts are preferred, while ventriculoperitoneal right atrial shunts are only performed when the patient is not suitable for ventriculoperitoneal shunts due to abdominal lesions, and other shunts are rarely used clinically. According to the cerebral pressure characteristics of normal cranial pressure hydrocephalus, it is appropriate to choose 60-90 mmH2O medium pressure shunt tube. The shunt effect should be estimated before surgery, and the indication for surgery should be carefully evaluated to achieve the maximum effect of surgery.