Clinically, hydrocephalus can be divided into transmissible hydrocephalus and obstructive hydrocephalus. Traffic hydrocephalus, also known as extraventricular obstructive hydrocephalus, is a hydrocephalus in which the cerebrospinal fluid circulation in the ventricular system is normal and the normal cerebrospinal fluid pathway below the fourth ventricular outlet is obstructed or impaired in absorption. Obstructive hydrocephalus is the most common type of hydrocephalus caused by obstruction of cerebrospinal fluid circulation in the ventricular system, i.e., obstruction of any part of the cerebrospinal fluid above the fourth ventricle.