Observations on the Activation of Chronic Compensated Hydrocephalus in Adult Patients

Abstract

There is no nomenclature consensus in describing patients with chronic form of exceptionally enlarged ventricles and no overt sign of increased intracranial pressure (ICP). There is a broad spectrum of compensated hydrocephalus and the underlying cause of this form of chronic compensated hydrocephalus has been questioned. Little attention has given to this entity and not so many studies have been made so far. There are confusing terms used to describe these conditions such as the syndrome of hydrocephalus in young and middle-aged adults (SHYMA), late-onset idiopathic aqueductal stenosis (LIAS), long-standing overt ventriculomegaly (LOVA) of the adult, and late-onset aqueductal stenosis (AS). Some authors proposed that LOVA must be considered as a special form of LIAS. Cerebrospinal fluid (CSF) dynamics may change over time between active and inactive states in these entities but the reason for late decompensation remains obscure. However, a new event in the central nervous system (CNS) may offset the compensatory mechanism in some patients. How to treat these patients is also a very controversial issue. Ventriculoperitoneal shunt (VPS) with adjustable valve or endoscopic third ventriculostomy (ETV) is generally selected. The authors illustrate their experiences and review Observations on the Activation of Chronic Compensated Hydrocephalus in Adult Patients