What is hydrocephalus?

Hydrocephalus is a condition that occurs when fluid builds up in the skull and causes the brain to swell. The name means “water on the brain.”

Brain damage can occur as a result of the fluid buildup. This can lead to developmental, physical, and intellectual impairments. It requires treatment to prevent serious complications.

Hydrocephalus mainly occurs in children and adults over 60, but younger adults can get it too. The National Institute of Neurological Disorders and Stroke (NINDS) estimates that 1 to 2 of every 1,000 babies are born with hydrocephalus.

Cerebrospinal fluid (CSF) flows through your brain and spinal cord in normal conditions. Under certainconditions, the amount of CSF in your brain increases. The amount of CSF can increase when:

  • a blockage develops that prevents CSF from flowing normally
  • there is a decrease in the ability of blood vessels to absorb it
  • your brain produces an excess amount of it

Too much of this fluid puts your brain under too much pressure. This pressure can cause brain swelling, which can damage your brain tissue.

Underlying causes

In some cases, hydrocephalus starts before a baby is born. This can result from:

  • a birth defect in which the spinal column doesn’t close
  • a genetic abnormality
  • certain infections that occur during pregnancy, such as rubella

This condition can also occur in infants, toddlers, and older children due to:

  • central nervous system infections such as meningitis, especially in babies
  • bleeding in the brain during or shortly after delivery, especially in babies born prematurely
  • injuries that occur before, during, or after delivery
  • head trauma
  • central nervous system tumors

Normal pressure hydrocephalus

When hydrocephalus occurs in adults, CSF levels rise but the amount of pressure is usually normal. It still causes the brain to swell and can lead to impaired functioning. In adults, this condition usually results from conditions that prevent CSF from flowing. However, in some cases, there is no known cause.

You might be at higher risk if you’ve experienced any of the following:

Hydrocephalus can cause permanent brain damage, so it’s important that you recognize symptoms of this condition and seek medical attention. The condition is more common in children, but it can affect people of any age.

Infants

Early signs of hydrocephalus in infants include:

  • bulging fontanel, which is the soft spot on the surface of the skull
  • a rapid increase in head circumference
  • eyes that are fixed downward
  • seizures
  • extreme fussiness
  • vomiting
  • excessive sleepiness
  • poor feeding
  • low muscle tone and strength

Toddlers and older children

Symptoms or signs that affect toddlers and older children include:

  • short, high-pitched cries
  • personality changes
  • changes in facial structure
  • crossed eyes
  • headaches
  • muscle spasms
  • delayed growth
  • trouble eating
  • extreme sleepiness
  • irritability
  • loss of coordination
  • loss of bladder control
  • larger than normal head
  • trouble staying awake or waking up
  • vomiting or nausea
  • seizures
  • problems concentrating

Young and middle-aged adults

Symptoms in young and middle-aged adults include:

Normal pressure hydrocephalus (NPH)

This form of the condition usually begins slowly and is more common in adults over the age of 60. One of the earliest signs is falling suddenly without losing consciousness. Other common symptoms of normal pressure hydrocephalus (NPH) include:

If you suspect that you or your child has hydrocephalus, your doctor will perform a physical exam to look for signs and symptoms. In children, doctors check for eyes that are sunken in, slow reflexes, a bulging fontanel, and a head circumference that is larger than normal for their age.

Your doctor may also use an ultrasound to get a closer look at the brain. These tests use high-frequency sound waves to create images of the brain. This type of ultrasound can only be done in babies whose fontanel (soft spot) is still open.

Magnetic resonance imaging (MRI) scans can be used to look for signs of excess CSF. MRIs use a magnetic field and radio waves to make a cross-sectional image of the brain.

Computerized tomography (CT) scans can also help diagnose hydrocephalus in children and adults. CT scans use several different X-rays to form a cross-sectional image of the brain. These scans can show enlarged brain ventricles that result from too much CSF.

Hydrocephalus can be fatal if it’s left untreated. Treatment may not reverse brain damage that’s already occurred. The goal is to prevent further brain damage. This involves restoring the normal flow of CSF. Your doctor may explore either of the following surgical options:

Shunt insertion

In most cases, a shunt is surgically inserted. The shunt is a drainage system made of a long tube with a valve. The valve helps CSF flow at a normal rate and in the right direction. Your doctor inserts one end of the tube in your brain and the other end into your chest or abdominal cavity. Excess fluid then drains from the brain and out the other end of the tube, where it can be more easily absorbed. A shunt implant is typically permanent and has to be monitored regularly.

Ventriculostomy

A procedure called a ventriculostomy can be performed as an alternative to having a shunt inserted. This involves making a hole at the bottom of a ventricle or in between ventricles. This allows CSF to leave the brain.

The outlook for someone with hydrocephalus depends largely on the extent of the symptoms. Many children experience lifelong brain damage. By working with professionals including pediatricians, special education teachers, mental health providers, occupational therapists, developmental therapists, and pediatric neurologists, children can learn to manage their disability and lessen the lifelong effects.

Adults with severe symptoms of hydrocephalus might need to work with occupational therapists. Others may require long-term care. Some might need the care of medical specialists who focus on dementia.

The long-term effects of this condition vary widely, depending on individual circumstances. Talk to your doctor for a more case-specific outlook.

You can’t prevent hydrocephalus, but you can lower your risk and your child’s risk for developing the condition.

Make sure you get prenatal care during pregnancy. This can help reduce your chance of going into premature labor, which can lead to hydrocephalus.

Getting vaccinations can help prevent illnesses and infections that are linked to hydrocephalus. Having regular screenings can also ensure that you get prompt treatment for illnesses or infections that could put you at risk of hydrocephalus.

Use safety equipment, such as helmets, to prevent head injuries when doing activities like riding a bike. You can also lower your risk of head injuries by always wearing a seat belt.

Young children should always be secured in a car seat. You can also prevent head injuries by making sure your baby equipment, such as strollers, meets safety standards.