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Overview
What Is Congenital Hydrocephalus?
Congenital hydrocephalus is a condition in which too much cerebrospinal fluid (CSF) collects in or around a baby’s brain. It is present at birth or develops before birth, although it may not be recognized until later. Pressure from the extra fluid can enlarge the brain’s fluid-filled spaces and affect the developing brain. This condition may affect newborns, infants, or children and can have many different causes.
Symptoms
Symptoms of Congenital Hydrocephalus
Signs before birth or at delivery
- Enlarged brain ventricles on a prenatal ultrasound (ventriculomegaly).
- An unusually large head size at birth (macrocephaly).
- A tense or bulging soft spot on the newborn’s head (fontanelle).
- Downward-looking eyes (sunsetting eyes).
- Separated skull bones (splayed sutures).
- Poor muscle tone (hypotonia).
Signs during infancy or childhood
- Rapid head growth.
- Vomiting.
- Poor feeding.
- Unusual sleepiness.
- Irritability.
- Developmental delay.
- Problems with balance or coordination.
- Headache in an older child.
Causes
What Causes Congenital Hydrocephalus?
Hydrocephalus develops when CSF cannot circulate or be absorbed normally. In obstructive hydrocephalus, a blockage prevents fluid from moving through the brain’s normal pathways. In communicating hydrocephalus, the pathways are open, but CSF circulation or absorption is impaired. The causes of congenital hydrocephalus may involve brain development, genetics, bleeding, infection, or other prenatal factors.
- A narrowing or blockage in the brain’s fluid pathways can cause obstructive hydrocephalus.
- Differences in brain or spinal cord development can interfere with normal CSF circulation.
- Neural tube conditions, including spina bifida, may be associated with hydrocephalus.
- Genetic syndromes or inherited changes may affect the development of the brain and its fluid pathways.
- Bleeding before or around birth can block CSF flow or reduce its absorption.
- Prenatal infections can affect brain development and contribute to fluid buildup.
- Other pregnancy or fetal complications may increase the risk without providing one clear cause.
Risk Factors
Risk Factors for Congenital Hydrocephalus
- A family history of hydrocephalus or certain inherited conditions may increase the likelihood.
- Genetic syndromes can affect the development of the brain and CSF pathways.
- Neural tube conditions, such as spina bifida, are associated with a higher risk.
- Differences in fetal brain development may be identified during pregnancy or after birth.
- Certain infections during pregnancy can affect the developing brain.
- Bleeding or other complications before birth may disrupt CSF circulation.
- Some cases are linked to a specific developmental or genetic condition, while others have no identifiable risk factor.
Complications
Complications of Congenital Hydrocephalus
- Developmental delays may affect the timing of motor, language, or social skills.
- Learning difficulties may become more noticeable as school demands increase.
- Vision problems can result from pressure on visual pathways or related brain differences.
- Movement or coordination problems may affect walking, balance, or fine motor skills.
- Seizures may occur in some children.
- Increased pressure can cause headaches, vomiting, sleepiness, or changes in alertness.
- Persistent fluid buildup may affect brain development if it is not treated or monitored.
TREATMENT-RELATED CONCERNS
Watch for changes after treatment
Shunts can become blocked, infected, or drain too much or too little fluid, and some children need a revision procedure as they grow. New or worsening symptoms in a child with a shunt require prompt medical assessment.
Diagnosis
How Is Congenital Hydrocephalus Diagnosed?
A prenatal ultrasound may show enlarged brain ventricles or other developmental differences before birth. After delivery, clinicians examine the baby, measure head growth over time, and look for signs of increased pressure or neurological changes. In an older infant or child, the evaluation also considers symptoms, development, vision, movement, and overall neurological function. These findings help determine whether hydrocephalus is present and what may be causing it.
- A cranial ultrasound can assess the brain through an open fontanelle in a newborn or young infant.
- Magnetic resonance imaging (MRI) provides detailed images of the brain, ventricles, and CSF pathways without radiation.
- Computed tomography (CT) may be used when imaging is urgently needed or MRI is not readily available.
- A physical and neurological examination assesses head size, reflexes, muscle tone, eye movements, and development.
- Genetic, infection-related, or other laboratory tests may be considered when an associated cause is suspected.
Treatment & Management
Treatment and Management
Hydrocephalus treatment is individualized. Some children with stable findings may be monitored closely with examinations, head-growth measurements, and repeat imaging, while significant or progressive fluid buildup commonly requires neurosurgical treatment. The goals are to control pressure, protect developing brain tissue, and support the child’s development.
SHUNT PROCEDURES
A shunt diverts excess CSF from the brain to another part of the body, where it can be absorbed. Shunts can be effective, but they may become blocked, infected, or require adjustment or revision, so lifelong monitoring may be needed.
ENDOSCOPIC PROCEDURES
An endoscopic third ventriculostomy may create an alternate pathway for CSF to leave the ventricles without placing a shunt. It is suitable only for some children, and the decision depends on the child’s anatomy, the type of blockage, and the underlying cause.
- Regular neurosurgical follow-up helps monitor fluid control, brain growth, and shunt function.
- Developmental assessments help identify needs in language, learning, behavior, or motor skills.
- Physical, occupational, or speech therapy may support movement, daily activities, communication, or feeding.
- Vision or hearing care may be needed when hydrocephalus or its underlying cause affects these senses.
- Urgent medical review is needed for possible shunt blockage, infection, or sudden symptom changes.
Outlook and Prognosis
Outlook and Prognosis
The outlook for a child with congenital hydrocephalus varies widely. Some children develop typically, while others need support for developmental, learning, movement, vision, or seizure-related concerns. Outcomes can be influenced by the cause, when fluid buildup began, its severity, associated brain differences, response to treatment, and access to developmental services. A child’s care team can explain the findings and track progress over time without assuming a fixed outcome.
When Should You See a Doctor
When Should You See a Doctor?
SEEK MEDICAL ADVICE
Contact your child's clinician
Contact your child’s pediatrician or specialist about concerning head growth, repeated vomiting, unusual sleepiness, feeding problems, new irritability, developmental changes, vision concerns, or other possible hydrocephalus symptoms. A clinician can decide whether the child needs an examination, head-growth check, or imaging. Do not wait for a routine visit if symptoms are worsening.
GET URGENT HELP
Do not wait for routine care
Seek immediate help for reduced responsiveness, a seizure, breathing problems, repeated vomiting, a rapidly enlarging head, or severe or rapidly worsening symptoms. For a child with a shunt, urgent assessment is needed for possible infection or blockage, including fever, redness or swelling along the shunt path, sudden headache, vomiting, or unusual sleepiness. Call local emergency services for life-threatening symptoms.
