Hydrocephalus

types, consequences and treatment

Hydrocephalus (HC) is a problem that can occur during any developmental period. HC is a result of cerebrospinal fluid in the ventricles and can seriously damage the developing brain by disturbing both cortical and subcortical functions. The increased volume of CSF causes the brains’ ventricles to expand and as they expand the cerebral tissue is compromised and the cranium distorts.

Hydrocephalus threatens healthy development of the brain and if left untreated the child may die or suffer severe mental retardation. HC often occurs secondary to other pathological events or processes such as congenital disorders (spina bifida is most common), infections, vascular abnormalities, tumors, cysts, traumatic brain injury and other disease processes.

In general one major type of hydrocephalus is known as “obstructive or noncommunicating HC” because tumors, congenital malformation or scarring that causes the obstruction or blocks communication on the CSF pathways. The most common pathway blocked is the long and narrow “aqueduct of Sylvius” in the third ventricle. Obstructive HC is congenital disorder that develops early in gestation and is associated with a range of affects on brain development. On the other hand “nonobstructive or communicating HC” is secondary to other congenital disorders, most commonly spina bifida. Nonobstructive HC occurs due to intaventricular hemorrhage in many premature infants. Intraventricular hemorrhages are often the result of pressure on the brain during the birthing process or breathing problems. This causes the vessels around the ventricles to rupture and bleed hemorrhage into the ventricles, clogging the arachnoid villa that is responsive for reabsorbing CSF into the bloodstream therefore the amount of CDP increases.

If left unchecked hydrocephalus has devastating impact on the brain and skull because the excess CSF disrupts brain anatomy and function. For example, the ventricle lining is damaged, cerebral blood vessels are distorted and become dysfunctional, and neurotransmitter concentration alters. This results in children having deficits in nonverbal, particularly visuospatial abilities and decreased motor performance.


The consequences of hydrocephalus are costly however because individuals have greater overall impairment of higher order cognitive abilities in advanced cases. Even with shunting treatment, children often show below-above average abilities in visual-perceptual and visuospatial abilities, motor skills (fine & gross), and memory capabiltiy. These are related to the disruption of the posterior cortical regions, cerebellum, corpus callosum, and other white matter pathways. On the other hand, poor motor skills are a consequence of damage to the cerebellum, basal ganglia, motor strip, and connecting white matter. The memory deficits associated with HC causes poor recall of both verbal and nonverbal contents, lower reading comprehension, math computation and problem solving, and writing sills. Individuals with HC often communicate in a way that lacks clarity, organization and relevance.

Hydrocephalus is treatable and most children with symptoms receive a shunt, which is a medical procedure that drains excessive CSF from the ventricular system into the stomach.

Overall, shunting has increased the number of hydrocephalus survivors and prevented global cognitive impairment. When children are free of other abnormalities they have few, if any cognitive impairments. In order to catch hydrocephalus early, doctors can identify it through an ultrasonography. It is easy to diagnose because of the characteristic quickly enlarging cranium, clear developmental delays and abnormal eye movements.