Hydrocephalus as it Relates to Cerebral Palsy
By Lee Vander Loop
CP Family Network Editor
Hydrocephalus is a Latin word meaning “water on the brain.” About 75% of children with hydrocephalus will have some form of motor disability. This can be in the form of cerebral palsy.
The best analogy I can think of to describe the relation between cerebral palsy and hydrocephalus is the swelling that can happen after you hurt your knee. The swelling is caused by fluid your body creates in response to the injury. Maybe over days and weeks your knee begins to feel better and the swelling goes down, but then you notice an area around your knee that feels like watery Jell-O. This is a result of your body’s inability to absorb all of the fluid it created in response to the injury. Your physician would likely put in a tube to drain the fluid and relieve the pressure to prevent damage to the surrounding tissue.
Now think of your knee as the human brain and the injury is due to oxygen deprivation (asphyxia) or another source of birth trauma.
In almost all cases of severe head and brain trauma, there’s swelling of the brain, also known as brain edema. The excess fluid causes pressure to build up between the brain and skull. This pressure can further damage the brain.
Cerebospinal fluid (CSF) is a clear and watery liquid that completely surrounds the brain and spinal cord tissue. The liquid circulates throughout the brain before being reabsorbed into the blood through the ventricles, a series of cavities in the brain. CSF protects the brain and spinal cord against any jarring forces, acting as a shock absorber. Scientists report CSF is also a potent mixture of proteins that supports brain cell development.
When there’s severe insult to the brain due to birth injury, the brain swells. Although the initial swelling may subside, the injury may result in damage to one or more ventricles, causing a blockage or damage to tissue responsible for absorption. Since the body is constantly making CSF, any delayed absorption or obstruction results in the buildup of fluid, causing the ventricles to balloon. This, in turn, leads to pressure on surrounding brain matter, pushing aside the soft tissue of the brain and leading to further cerebral damage.
Causes of Hydrocephalus
Hydrocephalus may be congenital or acquired. It occurs in approximately 1 of every 1,000 live births in the U.S., or 10,000 babies per year. About 50% of the cases are congenital, arising from genetic abnormalities or events that occur during fetal development, such as:
Acquired hydrocephalus develops at the time of birth or at some point afterward. This type of hydrocephalus can affect individuals of all ages and is caused by head trauma, brain hemorrhage, or disease such as brain cancer or meningitis.
Hydrocephalus is manageable. The most common treatment involves surgical placement of a shunt system. Using tubes, this system redirects the flow of fluid from an area of buildup to the abdominal cavity where it can be absorbed as part of the circulatory process. A valve within the shunt system allows doctors to adjust the flow to normalize pressure. Doctors insert a tube long enough to accommodate the child’s growth, thus eliminating the need for another surgery.
When severe birth trauma results in hydrocephalus, evidence of a fluid buildup may be present within days. There may be an appearance of puffiness or swelling at the temples, at the bridge of the nose, or possibly around the eyes. A newborn may need the use of a ventilator to help relieve pressure until the swelling can be assessed and brought under control. Diagnosing the condition early and treating it quickly can help limit any long-term problems. But long-term effects mostly depend on what caused the fluid buildup, how bad it got, and how the baby responded to treatment.
A very visible sign of hydrocephalus is an enlarged head. This occurs because the bones of the skull are not yet fused, and so the head can stretch and grow in an attempt to bring down the pressure of the cerebrospinal fluid. Symptoms of hydrocephalus in an infant also may include vomiting, sleepiness, irritability, an inability to look upward, and seizures.
Symptoms in older children and adults include headache, nausea, vomiting, and blurred vision. There may be problems with balance, delayed development in walking or talking, and poor coordination. If the cerebrospinal fluid pressure remains high for prolonged periods, blindness can occur in the older child or adult.
If left completely untreated, hydrocephalus can cause the brain stem to become so compressed that the heart can stop or breathing may cease. The compression of the cerebellum, while not as serious as a compressed brain stem, may lead to problems with swallowing, speaking, and breathing, or it can cause cerebral palsy to develop in fetuses and infants.
Many diagnostic tools are available to aid physicians and neurologists in the diagnosis of hydrocephalus, including:
- Cerebral angiography, which is a test used to detect blockages of the arteries or veins. Images are taken after a dye is injected into the area.
- Ultrasonography (USG) uses sound waves to take pictures of soft tissue organs deep within the body.
- Computed tomography, also known as a CT scan, takes two-dimensional images of organs, bones, and tissue. Neurological CT scans are used to view the brain and spine.
- Magnetic Resonance Imaging (MRI) uses computer-generated radio waves and a magnetic field to produce detailed images of body structures including tissue, organs, bones, and nerves.
- Cerebrospinal fluid analysis involves the removal of a small amount of fluid for testing and to measure intracranial pressure.
- Electroencephalography (EEG) monitors brain activity through the skull. EEG is used to help diagnose certain seizure disorders, brain tumors, brain damage from head injuries, inflammation of the brain and/or spinal cord, and metabolic and degenerative disorders that affect the brain.