Hydrocephalus: Frequently Asked Questions

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Hydrocephalus, sometimes called water on the brain, is the buildup of cerebrospinal fluid, or CSF, in areas deep within the brain. Normally, this fluid cushions and protects the brain, but if there is too much of it, it presses on brain tissue and can cause severe and dangerous damage. Hydrocephalus can develop before birth, in children, and in adults, but it’s important to diagnose and treat it promptly at any age.

What causes hydrocephalus?

Hydrocephalus can be congenital, meaning you are born with it, or it can be acquired, developing after an injury or disease. It occurs when the normal flow of fluid from one area of the brain to another is blocked or if the brain loses its ability to absorb fluid. Less often, the body produces more CSF than the brain needs.
Infections of the central nervous system, such as meningitis, can cause hydrocephalus. Bacterial meningitis can be prevented by a vaccine. Infections in the mother during pregnancy, like measles or an STD, can inflame brain tissue in the fetus and cause hydrocephalus. Bleeding in the brain can also lead to hydrocephalus, which sometimes occurs in preterm babies. In adults, the most common causes are tumors or brain injury.

Who is likely to get hydrocephalus?

It’s estimated that more than a million individuals in the United States have hydrocephalus. Anyone can develop it, but it is more common in infants and adults 60 and older. Up to 1 in 500 babies are born with the condition. Veterans who have sustained traumatic brain injury in combat are also at higher risk. Some experts believe it is underdiagnosed, especially in adults; in some cases, dementia caused by hydrocephalus may be mistaken for Alzheimer’s disease.

Does hydrocephalus run in families?

Hydrocephalus can be genetic due to a defective gene passed from parent to child. Experts haven’t confirmed the genetic error, but they suspect a mutation of a gene that causes a syndrome called L1, which stiffens the ventricles (cavities) in the brain and makes it hard for the fluid to flow out of the area. The L1 syndrome mostly affects male babies; it is rarely seen in females. Spina bifida is another genetic defect that can cause hydrocephalus in babies.

What are the signs and symptoms of hydrocephalus in infants and children?

In infants, the signs of hydrocephalus are a large or rapidly growing head and a bulge in the fontanel, the “soft spot” on top of the head where the bones have not fully grown together. The baby may be irritable, sleep poorly, vomit, have trouble sucking, have seizures, and a fixed, downward gaze. They may also have poor muscle tone, be unresponsive to touch, and grow slowly. Toddlers may have headaches, blurred vision, lethargy, poor coordination and appetite. They may seem to lose part or all of some skills, such as walking, and may show personality changes.

Regularly scheduled well-baby visits with a pediatrician can help catch signs and symptoms of hydrocephalus in infants.

What are the signs and symptoms of hydrocephalus in young adults?

Some of the symptoms of hydrocephalus in young adults are similar to those of children, including headache, sleepiness, and loss of coordination. They may also need to urinate frequently or lose control of their bladder. Young adults with hydrocephalus may have impaired vision and an inability to think clearly, with poor memory and concentration.

What are the signs and symptoms of hydrocephalus in older adults?

In adults older than 60, in addition to bladder control problems and memory loss or unclear thinking, their general movements may slow down. They may start to shuffle, due to a sensation that people describe as a feeling that their feet are “stuck.”

How do doctors diagnose hydrocephalus?

Doctors perform a physical exam and ask the patient (or parent if the patient is a baby) about symptoms. Consultation with an ophthalmologist will determine if optic nerve swelling (a key diagnostic feature) is present. If there is reason to suspect hydrocephalus, the doctor will order an imaging test, such as an ultrasound or MRI, to see if there is excess fluid buildup in the brain. Doctors can detect fetal hydrocephalus with an ultrasound during pregnancy from about the 15th to the 35th week, which they can confirm with a fetal MRI.

How do doctors treat hydrocephalus?

Doctors redirect the excess fluid through a flexible tube called a shunt. One end is surgically inserted into a hollow fluid compartment within the brain and the opposite end drains the fluid into the abdominal cavity. The CSF shunt will remain in place and patients should be monitored on a regular basis because sometimes shunt drainage can stop unexpectedly. Without a shunt most people will need to have fluid removed periodically, whenever it builds up and begins to press on brain tissue. About half of children may need to have their shunt replaced at some point, often within the first two years of insertion. Some people can have an endoscopic procedure called a ventriculostomy to make a small hole in the brain that diverts fluid.

Physical and occupational therapy can address developmental challenges in children with hydrocephalus and many live relatively normal lives. In milder cases, a baby with hydrocephalus may develop completely normally.

What are the complications of hydrocephalus?

Children with severe hydrocephalus can develop permanent brain damage, leading to seizures, learning or developmental disabilities, short-term memory problems, and problems with coordination and vision. They may also reach puberty early. When treated, milder cases may have few, if any, serious complications in younger people.

Adults with hydrocephalus who have a significant decline in memory or reasoning often continue to have symptoms, even after treatment. Physical and occupational therapy may help movement problems.

Can hydrocephalus be fatal?

Left untreated, hydrocephalus can be fatal, but early diagnosis and treatment are often successful in saving lives. Hydrocephalus does not go away on its own and symptoms typically worsen if the condition is not treated, though some people may experience temporary improvements. While the outlook varies widely from person to person, some people recover almost completely and have a good quality of life.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Jan 21
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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