Hydrocephalus
Also called: Water on the brain
Hydrocephalus is the buildup of too much cerebrospinal fluid in the brain. Normally, this fluid cushions your brain. When you have too much, though, it puts harmful pressure on your brain.
There are two kinds of hydrocephalus. Congenital hydrocephalus is present at birth. Causes include genetic problems and problems with how the fetus develops. An unusually large head is the main sign of congenital hydrocephalus. Acquired hydrocephalus can occur at any age. Causes can include head injuries, strokes, infections, tumors and bleeding in the brain. Symptoms of acquired hydrocephalus can include
Hydrocephalus can permanently damage the brain, causing problems with physical and mental development. If untreated, it is usually fatal. With treatment, many people lead normal lives with few limitations. Treatment usually involves surgery to insert a shunt. Medicine and rehabilitation therapy can also help.
National Institute of Neurological Disorders and Stroke
Hydrocephalus
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§ Causes |
Introduction
Hydrocephalus occurs when excess fluid builds up in your brain, most often because of an obstruction preventing proper fluid drainage. The excess fluid can push fragile brain tissues up against the skull — causing brain damage and, if left untreated, even death.
Once known as "water on the brain," hydrocephalus is sometimes present at birth, although it may develop later. About one out of 500 children are born with the disorder. The outlook for people with hydrocephalus depends on how quickly the condition is diagnosed and whether any underlying disorders are present.
Signs and symptoms
The signs and symptoms of hydrocephalus vary by age group and disease progression. In infants, common signs and symptoms of hydrocephalus include:
§ An unusually large head
§ A rapid increase in the size of the head
§ A bulging "soft spot" on the top of the head
§ Vomiting
§ Sleepiness
§ Irritability
§ Seizures
§ Eyes fixed downward (sunsetting of the eyes)
§ Developmental delay
In older children and adults, common signs and symptoms of hydrocephalus include:
§ Headache followed by vomiting
§ Nausea
§ Blurred or double vision
§ Eyes fixed downward (sunsetting of the eyes)
§ Problems with balance, coordination or gait
§ Sluggishness or lack of energy
§ Slowing or regression of development
§ Memory loss
§ Confusion
§ Urinary incontinence
§ Irritability
§ Changes in personality
Hydrocephalus produces different combinations of these signs and symptoms, depending on its cause, which also varies by age. For example, a condition known as normal pressure hydrocephalus, which mainly affects older people, typically starts with difficulty walking. Urinary incontinence often develops, along with a type of dementia marked by slowness of thinking and information processing.
Causes
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Your brain is the consistency of gelatin, and it floats in a bath of cerebrospinal fluid. This fluid also fills large open structures, called ventricles, which lie deep inside your brain. The fluid-filled ventricles help keep the brain buoyant and cushioned.
Cerebrospinal fluid flows through the ventricles by way of interconnecting channels. The fluid eventually flows into closed spaces between the brain and skull, where it's absorbed into your bloodstream.
Keeping the production, flow and absorption of cerebrospinal fluid in balance is important to maintaining normal pressure inside your skull. Hydrocephalus results when the flow of cerebrospinal fluid is disrupted — for example, when a channel between ventricles becomes narrowed — or when your body doesn't properly absorb this fluid.
Defective absorption of cerebrospinal fluid causes normal pressure hydrocephalus, seen most often in older people. In normal pressure hydrocephalus, excess fluid enlarges the ventricles but does not increase pressure on the brain. Normal pressure hydrocephalus may be the result of injury or illness, but in most cases the cause is unknown.
Risk factors
Premature infants have an increased risk of severe bleeding within the ventricles of the brain (intraventricular hemorrhage), which can lead to hydrocephalus. Certain problems during pregnancy, such as an infection within the uterus, may increase an infant's risk of developing hydrocephalus — as may problems in fetal development, such as incomplete closure of the spinal column.
Congenital or developmental defects not apparent at birth also can increase older children's risk of hydrocephalus. Lesions or tumors of the brain or spinal cord, central nervous system infections, bleeding in the brain, and severe head injury can increase the risk as well.
When to seek medical advice
Seek immediate medical care by calling 911 or other emergency help or by going to the emergency room for these signs and symptoms in an infant or toddler:
§ A high-pitched cry
§ Problems with sucking or feeding
§ Exhibiting an unwillingness to bend or move the neck or head
§ Breathing difficulties
§ Seizures
The following signs and symptoms don't constitute an emergency, but they do warrant a call to your child's doctor:
§ A rapid increase in the size of the head
§ A bulging "soft spot" on the top of the head
§ A change in the appearance of the face or eyes
Older adults with walking difficulties that can't be attributed to arthritis or injury should have a complete physical and neurological exam.
Screening and diagnosis
Your doctor may diagnose congenital hydrocephalus in your unborn child during a routine prenatal ultrasound, or the condition may be discovered during infancy or early childhood, when the head is regularly measured as part of growth monitoring. If your baby's head is visibly enlarged or its growth over time is more rapid than that of other infants, your doctor may recommend an ultrasound of the head. If the results of the ultrasound are abnormal, your infant will need further evaluation.
The evaluation of an older child or an adult who develops signs or symptoms of hydrocephalus begins with a careful medical history and a physical and neurological examination. Computerized tomography (CT) or magnetic resonance imaging (MRI) can provide detailed pictures of the brain. If these pictures reveal hydrocephalus or other abnormalities, referral to a brain surgeon for further evaluation and treatment is likely.
Complications
The severity of hydrocephalus depends on the age at which the condition develops and the course it follows. If the condition is well advanced at birth, major brain damage and physical disabilities are likely. In less severe cases, with proper treatment, it's possible to have a nearly normal life span and intelligence.
Treatment
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The most common treatment for hydrocephalus is the surgical insertion of a drainage system, called a shunt. It consists of a long flexible tube with a valve that keeps fluid from the brain flowing in the right direction and at the proper rate. One end of the tubing is usually placed in one of the brain's ventricles. The tubing is then tunneled under the skin to another part of the body where the excess cerebrospinal fluid can be more easily absorbed — such as the abdomen or a chamber in the heart.
People who have hydrocephalus usually need a shunt system for the rest of their lives, so additional surgeries may be needed to insert longer tubing to match a child's growth. Revisions to the shunt also may be needed if the tubing becomes blocked or infected.
Another surgical option — ventriculostomy — is sometimes used when there's an obstruction of flow between ventricles. In the procedure, your surgeon makes a hole in the bottom of one of the ventricles, to allow the cerebrospinal fluid to flow toward the base of the brain, where normal absorption occurs.
Prevention
§ Get regular prenatal care to reduce your risk of premature labor, which places your baby at risk of hydrocephalus and other complications.
§ Protect your baby or child from head injuries by using a properly installed, age- and size-appropriate child safety seat on all car trips. Make sure all your baby equipment — crib, stroller, swing, high chair — meets all safety standards and is properly adjusted for your baby's size and development.
§ Keep your child's immunizations up-to-date. Vaccines that prevent some types of meningitis — once a common cause of hydrocephalus — are now on the immunization schedule for healthy infants and children.
Coping skills
With the help of rehabilitation therapies and educational interventions, many people with hydrocephalus live with few limitations. Children with developmental problems due to hydrocephalus may be eligible for government-sponsored health care and other support services. Check with your state or county social services agency. Children's hospitals and voluntary organizations serving people with disabilities are also good resources for emotional and practical support, as are doctors and nurses.
