Hydrocephalus

What is Hydrocephalus?

Hydrocephalus is a condition in which cerebrospinal fluid, also called CSF, builds up inside the brain’s ventricles. The ventricles are normal fluid-filled spaces in the brain. When CSF does not flow or absorb normally, the ventricles can enlarge and pressure can affect brain function.

Hydrocephalus can be obstructive, meaning CSF flow is blocked, or communicating, meaning CSF flow is not blocked but absorption is impaired. Adults may also develop normal pressure hydrocephalus, often called NPH, which can cause walking problems, cognitive changes, and urinary symptoms even when pressure readings are not always high.

De Novo Brain & Spine evaluates adult patients with suspected or confirmed hydrocephalus to help determine the appropriate next step. Evaluation may include neurological examination, CT imaging, brain MRI, review of ventricular size, assessment for CSF obstruction, lumbar puncture in selected cases, shunt evaluation, or neurosurgical treatment planning when appropriate.

Common Signs and Symptoms

Hydrocephalus symptoms depend on the type of hydrocephalus, how quickly CSF builds up, ventricular size, pressure in the brain, and the underlying cause.

Common signs and symptoms may include:

• Headache
• Nausea or vomiting
• Blurred vision, double vision, or sensitivity to light
• Balance problems or trouble walking
• Dizziness or poor coordination
• Memory problems, confusion, or difficulty concentrating
• Sleepiness, fatigue, or decreased alertness
• Urinary urgency, frequency, or incontinence
• Slowed movement or a shuffling gait, especially with normal pressure hydrocephalus
• Personality changes, mood changes, or reduced interest in daily activities
• New weakness, numbness, or neurological changes in selected cases
• Recurrence of symptoms in a patient with a prior shunt or CSF diversion procedure

Seek emergency medical care or call 911 for severe or rapidly worsening headache, repeated vomiting, new confusion, severe sleepiness, seizure, sudden weakness, sudden speech difficulty, sudden vision loss, loss of consciousness, or rapid neurological decline.

What Causes This Condition?

Hydrocephalus occurs when cerebrospinal fluid is produced, circulated, or absorbed abnormally. The cause may be clear in some patients and uncertain in others.

Possible causes and related conditions may include:

• Obstruction of CSF flow from a brain tumor, colloid cyst, ventricular tumor, cyst, scar tissue, or narrowing of a CSF pathway
• Brain hemorrhage, including subarachnoid hemorrhage or intraventricular hemorrhage
• Traumatic brain injury
• Infection or inflammation affecting the brain or meninges
• Prior brain surgery or scarring around CSF pathways
• Normal pressure hydrocephalus, which may be idiopathic, meaning no clear cause is identified
• Congenital or developmental conditions that may persist into adulthood or be diagnosed later
• Reduced CSF absorption after bleeding, infection, or inflammation

These are causes or contributing factors, not guarantees that hydrocephalus will occur. Treatment planning depends on the type of hydrocephalus, symptoms, imaging findings, CSF flow pattern, neurological examination, and the patient’s overall health.

How It Is Diagnosed?

Hydrocephalus cannot be diagnosed by symptoms alone. Diagnosis usually requires medical history, neurological examination, and brain imaging.

Common diagnostic steps may include:

• Medical history and neurological examination to evaluate headache, vision, gait, balance, strength, sensation, reflexes, memory, alertness, and urinary symptoms
• CT scan of the head, often used in urgent situations to evaluate ventricular enlargement, bleeding, mass effect, or acute neurological changes
• MRI of the brain to evaluate the ventricles, CSF pathways, brain structures, tumors, cysts, scarring, or signs of obstruction
• MRI CSF flow studies in selected cases when CSF movement or obstruction needs further evaluation
• Comparison with prior imaging to determine whether the ventricles are stable, enlarging, or changing over time
• Lumbar puncture, also called a spinal tap, in selected cases, especially when normal pressure hydrocephalus is being evaluated
• Large-volume lumbar puncture or lumbar drainage trial in selected patients with suspected normal pressure hydrocephalus
• Gait testing and cognitive assessment when normal pressure hydrocephalus is suspected
• Shunt series X-rays, CT, MRI, or shunt function evaluation in patients who already have a shunt and may have shunt malfunction or overdrainage
• Ophthalmologic examination in selected cases when vision changes or increased pressure is a concern

The goal of diagnosis is to determine whether hydrocephalus is present, identify the likely cause, assess urgency, and decide whether monitoring, CSF diversion, treatment of an underlying condition, or surgery may be appropriate.

What Information Can Be Helpful During a Hydrocephalus Evaluation?

Information about when symptoms began and whether they have changed over time can provide useful context during a hydrocephalus evaluation. Previous brain imaging, neurological records, and information about prior brain surgery or cerebrospinal fluid procedures may also be relevant.

For patients who already have a shunt, details about the type of shunt, previous revisions, and earlier imaging may help healthcare professionals understand the patient’s history more clearly.

Treatment Options

Hydrocephalus treatment depends on the type of hydrocephalus, cause, symptoms, ventricular size, CSF flow pattern, neurological examination, urgency, prior shunt history, surgical risk, and the patient’s overall health. Not every patient requires the same treatment approach.

Treatment options may include:

• Observation with repeat imaging for selected patients when ventricles are stable, symptoms are mild or uncertain, and urgent treatment is not needed
• Treatment of the underlying cause, such as addressing a tumor, cyst, hemorrhage, infection, or obstruction when clinically appropriate
• Temporary external ventricular drain, also called an EVD, in urgent situations when CSF needs to be drained and pressure needs to be monitored
• Ventriculoperitoneal shunt, also called a VP shunt, to divert CSF from the ventricles to the abdomen, where it can be absorbed
• Ventriculoatrial or ventriculopleural shunt in selected cases when another drainage site is more appropriate
• Endoscopic third ventriculostomy, also called ETV, a procedure that creates a new pathway for CSF flow in selected obstructive hydrocephalus cases
• Shunt revision when an existing shunt is blocked, infected, overdraining, underdraining, disconnected, or no longer working as intended
• Medication for symptom support in selected cases, although medication usually does not replace CSF diversion when hydrocephalus requires surgery
• Rehabilitation and supportive care to help with walking, balance, strength, cognition, bladder control, or daily function when symptoms are present

Neurosurgical treatment may be considered when hydrocephalus causes symptoms, ventricular enlargement, increased pressure, gait decline, cognitive change, urinary dysfunction, visual symptoms, or neurological decline. The safest plan depends on the cause of hydrocephalus and the patient’s individual condition.