Hydrocephalus

DEFINITION

Hydrocephalus is the buildup of fluid in the cavities (ventricles) deep within the brain. The excess fluid increases the size of the ventricles and puts pressure on the brain.

Cerebrospinal fluid normally flows through the ventricles and bathes the brain and spinal column. But the pressure of too much cerebrospinal fluid associated with hydrocephalus can damage brain tissues and cause a large spectrum of impairments in brain function.

Although hydrocephalus can occur at any age, it’s more common among infants and older adults.

Surgical treatment for hydrocephalus can restore and maintain normal cerebrospinal fluid levels in the brain. A variety of interventions are often required to manage symptoms or functional impairments resulting from hydrocephalus.

CAUSES

Hydrocephalus is caused by an imbalance between how much cerebrospinal fluid is produced and how much is absorbed into the bloodstream.

Cerebrospinal fluid is produced by tissues lining the ventricles of the brain. It flows through the ventricles by way of interconnecting channels and eventually flows into spaces around the brain and spinal column. It’s absorbed primarily by blood vessels in tissues near the base of the brain.

Cerebrospinal fluid plays an important role in brain function by:

• Keeping the brain buoyant, allowing the relatively heavy brain to float within the skull
• Cushioning the brain to prevent injury
• Removing waste products of the brain’s metabolism
• Flowing back and forth between the brain cavity and spinal column to maintain a constant pressure within the brain — compensating for changes in blood pressure in the brain

Excess cerebrospinal fluid in the ventricles occurs for one of the following reasons:

• Obstruction. The most common problem is a partial obstruction of the normal flow of cerebrospinal fluid, either from one ventricle to another or from the ventricles to other spaces around the brain.
• Poor absorption. Less common is a problem with the mechanisms that enable the blood vessels to absorb cerebral spinal fluid. This is often related to inflammation of brain tissues from disease or injury.
• Overproduction. Rarely, the mechanisms for producing cerebrospinal fluid create more than normal and more quickly than it can be absorbed.

SYMPTOMS

The signs and symptoms of hydrocephalus vary generally by age of onset.

Infants

Common signs and symptoms of hydrocephalus in infants include:

Changes in the head

• An unusually large head
• A rapid increase in the size of the head
• A bulging or tense soft spot (fontanel) on the top of the head

Physical symptoms

• Vomiting
• Sleepiness
• Irritability
• Poor feeding
• Seizures
• Eyes fixed downward (sunsetting of the eyes)
• Deficits in muscle tone and strength, responsiveness to touch, and expected growth

Toddlers and older children

Among toddlers and older children, signs and symptoms may include:

Physical symptoms

• Headache
• Blurred or double vision

Physical signs

• Abnormal enlargement of a toddler’s head
• Sleepiness
• Difficulty remaining awake or waking up
• Nausea or vomiting
• Unstable balance
• Poor coordination
• Poor appetite
• Seizures

Behavioral and cognitive changes

• Irritability
• Change in personality
• Problems with attention
• Decline in school performance
• Delays or problems with previously acquired skills, such as walking or talking

Young and middle-aged adults

Common signs and symptoms in this age group include:

• Headache
• Difficulty in remaining awake or waking up
• Loss of coordination or balance
• Loss of bladder control or a frequent urge to urinate
• Impaired vision
• Decline in memory, concentration and other thinking skills that may affect job performance

Older adults

Among adults 60 years of age and older, the more common signs and symptoms of hydrocephalus are:

• Loss of bladder control or a frequent urge to urinate
• Memory loss
• Progressive loss of other thinking or reasoning skills
• Difficulty walking, often described as a shuffling gait or the feeling of the feet being stuck
• Poor coordination or balance
• Slower than normal movements in general

When to see a doctor

Seek emergency medical care for infants and toddlersexperiencing these signs and symptoms:

• A high-pitched cry
• Problems with sucking or feeding
• Unexplained, recurrent vomiting
• An unwillingness to bend or move the neck or head
• Breathing difficulties
• Seizures

Seek prompt medical attention for other signs or symptoms in any age group.

Because more than one condition can result in the problems associated with hydrocephalus, it’s important to get a timely diagnosis and appropriate care.