Neuroophthalmological Signs of Hydrocephalus

Abstract

Hydrocephalus is an abnormal accumulation of cerebrospinal fluid (CSF) within the cranial cavity. In hydrocephalus ex vacuo, the amount of CSF increases in response to brain atrophy without an increase in intracranial pressure (ICP). In most cases, however, hydrocephalus is associated with increased CSF pressure.12 The usual cause is an obstruction of the flow of CSF at some point from its production at the choroid plexuses to its resorption by the arachnoid granulations. This syndrome is termed “noncommunicating hydrocephalus.” The lesion may be congenital, e.g., atresia of the aqueduct of Sylvius or the Arnold- Chiari or Dandy-Walker malformations, or it may be acquired, e.g., from tumors, infection, or hemorrhage.49 The site of obstruction determines which portion of the ventricular system will be affected. The obstruction may be within the basal cisterns, in which case the entire ventricular system dilates. If the obstruction is within the ventricular system itself, dilatation of the ventricular system occurs proximal to the site of obstruction.