Pediatric Hydrocephalus is a condition in which the clear fluid that normally protects the brain builds up excessive pressure within the brain. This clear brain fluid is known as Cerebral Spinal Fluid (CSF), and its function is to provide buoyancy for the brain and to protect it from shock, as well as to provide nutrition and to carry away waste. CSF is produced within the brain and circulates around the brain and spinal cord, around the meninges (the outer covering of the brain and spinal cord), and within the brain’s open cavities (called ventricles). Normally, there is an equilibrium between CSF produced and the CSF being absorbed. However, in hydrocephalus, more CSF is produced than absorbed, allowing abnormally high pressure to build up within the brain.
Hydrocephalus can have a rapid or a gradual onset. It can be present during fetal development, after birth, or into childhood depending upon the root cause. Rapid onset hydrocephalus is a medical emergency generally caused by traumatic injury or infection. Gradual onset hydrocephalus, on the other hand, is usually first detected by measuring an infant’s head circumference. An unusually large head or unusually rapid head growth may be an indication that brain fluid is building up within the brain’s interior, causing outward pressure against the skull. The bones within an infant and child’s skull are not fused and may expand if the brain expands. Other symptoms in infants include sleepiness, “sunsetting” (a downward gaze of the eyes), vomiting, irritability, and seizures. In older children, symptoms include nausea, balance issues, poor coordination, trouble walking, slowing of development, lethargy, drowsiness, or changes in cognition. A physician may also see a swelling of the ocular nerve in older children.
In order to diagnose hydrocephalus, a neurologist will typically order a CT scan or an MRI. In a very young baby with a large fontanelle (soft spot in the skull), an ultrasound may be used to make a diagnosis. Unfortunately, without treatment, a child’s brain will undergo further damage due to increasing pressure and can ultimately lead to death.