pediatrics
Hydrocephalus
Etiology of Hydrocephalus
Hydrocephalus can be either congenital or acquired from events during or after birth. It can be divided into two categories: Obstructive hydrocephalus: Results from obstruction of cerebrospinal fluid (CSF) flow Communicating hydrocephalus: Results from impaired resorption of CSF , a partner molecule, often also cause Schizencephaly with hydrocephalus resulting from aqueductal stenosis, and manifest autosomal dominant inheritance. Genes 1.Shaheen R, Sebai MA, Patel N, et al: The genetic landscape of familial hydrocephalus.Ann Neurol81(6):890–897, 2017. doi: 10.1002/ana.24964 Obstruction most often occurs in the aqueduct of Sylvius but sometimes at the outlets of the 4th ventricle (Luschka and Magendie foramina). The most common causes of obstructive hydrocephalus are Aqueductal stenosis Dandy-Walker malformation Chiari II type malformation Aqueductal stenosis is narrowing of the outflow pathway for CSF from the 3rd ventricle to the 4th ventricle. It may be either primary, or secondary to scarring or narrowing of the aqueduct resulting from a tumor, hemorrhage, or infection. Primary aqueductal stenosis may involve true stenosis (forking of the aqueduct into smaller, poorly functioning channels) or presence of a septum in the aqueduct. Primary aqueductal stenosis may be inheritable; there are many genetic syndromes, some of which are X-Linked Recessive (thus male infants inherit the condition from otherwise unaffected mothers). Dandy-Walker malformation comprises progressive cystic enlargement of the 4th ventricle in fetal life, resulting in complete or partial agenesis of the cerebellar vermis and hydrocephalus. It is likely related to a failure of formation of the foramen of Magendie in the fetus. Associated anomalies of the central nervous system are common, including agenesis of the corpus callosum and heterotopias. Dandy-Walker malformation accounts for 5 to 10% of cases of congenital hydrocephalus. In Chiari II (formerly Arnold-Chiari), hydrocephalus occurs with Spina Bifida and Impaired resorption in the subarachnoid spaces usually results from meningeal inflammation, secondary either to infection or to blood in the subarachnoid space resulting from either Subarachnoid hemorrhage or 