Hydrocephalus

Hydrocephalus is an abnormal buildup of cerebrospinal fluid in or around the brain. This extra fluid can enlarge the brain’s ventricles and increase pressure or affect how the brain works. Hydrocephalus may be present at birth or develop later in babies, children, or adults. In simple terms, this hydrocephalus definition describes a problem with the movement, absorption, or buildup of cerebrospinal fluid.

Symptoms in Babies and Infants

Symptoms in Older Children and Adults

Hydrocephalus can occur when cerebrospinal fluid flow is blocked, when the body cannot absorb the fluid properly, or, rarely, when too much fluid is produced. Possible causes include differences in brain or spinal cord development before birth, bleeding, infection, tumors, inflammation, head injury, and other medical conditions. Some people have congenital hydrocephalus, meaning it is present at birth, while others develop it later. In some cases, no single cause can be identified.

Shunt-Related Complications

A hydrocephalus shunt can become blocked or infected, drain too much fluid (overdrainage), or drain too little fluid (underdrainage). These problems may require assessment, treatment, or revision surgery. Complications vary according to age, cause, how long fluid has built up, and the treatment used. New or worsening symptoms after shunt placement require prompt medical assessment.

Clinicians begin with a medical history and neurologic examination. In babies, they may assess head growth, feeding, alertness, eye movements, and development; in older children and adults, they may assess thinking, walking, balance, strength, coordination, and eye movements. The pattern and timing of symptoms help the healthcare team consider hydrocephalus and possible causes.

Brain Imaging

Brain imaging helps clinicians evaluate ventricle size and look for changes in cerebrospinal fluid flow, bleeding, tumors, or other causes. Ultrasound may be used for some infants while the soft spot is open. MRI provides detailed images, and CT may be used when a rapid assessment is needed or MRI is not suitable.

Selected adults with suspected normal pressure hydrocephalus may have additional testing, such as a lumbar puncture or temporary cerebrospinal fluid drainage. Improvement in walking, thinking, or other symptoms after fluid removal may help the care team judge whether treatment could be beneficial.

Hydrocephalus treatment aims to restore or maintain cerebrospinal fluid flow and reduce harmful pressure or its effects. Rapidly worsening or symptomatic hydrocephalus may require urgent neurosurgical care. The treatment plan depends on age, cause, symptoms, imaging findings, and overall health.

Cerebrospinal Fluid Shunts

A shunt uses a catheter and valve to redirect cerebrospinal fluid from the brain’s ventricles to another part of the body, often the abdomen, where the fluid can be absorbed. Ventriculoperitoneal shunts are commonly used, although other shunt pathways may be appropriate in selected situations. Regular follow-up helps monitor shunt function, symptoms, growth or development, and possible blockage, infection, overdrainage, or underdrainage.

Endoscopic and Long-Term Management

Endoscopic third ventriculostomy creates an opening that allows cerebrospinal fluid to bypass certain blockages and may be suitable for selected people with obstructive hydrocephalus. Other procedures may address the underlying cause or revise a poorly functioning shunt. Supportive rehabilitation, developmental services, school or workplace accommodations, and individualized monitoring can help manage persistent effects. Normal pressure hydrocephalus treatment may include a shunt when testing and the overall clinical picture suggest that symptoms are likely to improve.

Hydrocephalus can often be managed, but some people need lifelong follow-up. Early recognition and treatment may reduce complications, although outcomes vary with the cause, age, timing of treatment, response to treatment, and other health conditions. Some people continue to have developmental, cognitive, movement, vision, or bladder-related effects. Ongoing care is especially important for people with a shunt or chronic hydrocephalus.

Persistent, progressive, or unexplained symptoms such as headaches, walking changes, memory problems, bladder changes, or developmental concerns should be discussed with a healthcare professional, even when there is no emergency.