Mechanism and research progress on secondary hydrocephalus

Hydrocephalus is one of the most common neurosurgical disorders, which is characterized by enlargement of ventricles and disrupted cerebrospinal fluid (CSF) homeostatis. Hydrocephalus is divided into multiple categories, of which trauma, posthemorrhagic and postinfectious hydrocephalus are the most important clinical types. Mechanism of secondary hydrocephalus is still unknown. In recent years, researches observed inflammation in both postinfectious hydrocephalusand posthemorrhagic hydrocephalus. Regulated inflammation is a significant protective respond that eliminates foreign pathogens, while abnormal inflammation deteriorates tissue damage. Apart from the traditional CSF homeostatis model, accumulating evidence have shown that neuroinflammation plays an important role in secondary hydrocephalus. This article reviews epidemiology, mechanisms and treatment of secondary normal pressure hydrocephalus. Understanding the mechanisms of secondary hydrocephalus might be helpful in developing more effective therapies.