Theories of cerebrospinal fluid dynamics and hydrocephalus: historical trend

According to the CSF bulk flow theory, hydrocephalus is caused by an imbalance between CSF formation and absorption, or a block at various locations in the major CSF pathway. New theories, however, have been proposed in which minor CSF pathways may play a significant role in the development of congenital hydrocephalus. The authors review major contributions to the literature and analyze the evolution of theories of CSF dynamics in relation to hydrocephalus, dividing their development into 4 stages on the basis of historical trends. In Stage I (prior to 1950), 2 systems of classifying hydrocephalus were proposed, namely Dandy's classifications of communicating and noncommunicating hydrocephalus and Russell's nonobstructive and obstructive hydrocephalus. In Stage II (1950–1974), based on these theories of major CSF pathway dynamics, treatment focused on ventriculostomy as an alternative to reduction of CSF production by choroid plexus coagulation. In Stage III (1975–1999), some of the specific forms of hydr...