Your brain is soft tissue floating in the liquid inside your skull. This liquid is cerebrospinal fluid (CSF). Tissues that line the cavities in your brain called ventricles make CSF. It then flows around the brain and spinal cord and into your bloodstream.

Hydrocephalus is when this fluid builds up in the ventricles. Your brain may make too much CSF. Something may be blocking the flow of fluid, or your blood may not absorb it.

The pressure of the additional fluid can widen your ventricles and push the brain against the skull, harming it. This pressure can cause neurological changes. Symptoms can include:

• Balance problems
• Bladder control problems
• Blurry vision
• Enlarged head (in an infant)
• Headache
• Thinking and memory problems
• Vomiting and nausea

Damage can be permanent and fatal if untreated. But treatments are available. In many cases, these can help you or your child live a normal life with few limitations.

The types of hydrocephalus differ based on the cause of the increased pressure or blockages. 

• Communicating hydrocephalus: The CSF still flows between the ventricles. A blockage, reduced flow, or absorption issue causes fluid to build up.
• Non-communicating hydrocephalus: A blockage develops in one or more narrow passages connecting the ventricles. CSF no longer flows between the ventricles, so it builds up. It's sometimes due to bleeding, infection, or injury, but often doesn't have a specific cause.
• Normal pressure hydrocephalus: The amount of fluid in the brain slowly increases without increasing pressure. It happens in adults and older people, so it's often mistaken for Alzheimer's disease.
• Idiopathic intracranial hypertension: The pressure in the brain is abnormally elevated without a known cause. It's also called pseudotumor cerebri. It may cause headaches or visual loss but isn't life-threatening.
• Hypersecretory hydrocephalus: A tumor that makes CSF increases the fluid pressure in the brain, but the ventricles don't enlarge.

Congenital vs. acquired

Your child may be born with hydrocephalus, or you, your loved one, or your child can develop it later. If you're born with it, it's called congenital. Often, this is due to a genetic issue, brain bleed, developmental issue, or an infection during pregnancy. It can cause an unusually large head.

Causes of congenital hydrocephalus include:

• Aqueductal stenosis: A narrowed cerebral aqueduct slows or blocks the flow of CSF.
• Myelomeningocele: A severe type of spina bifida in which the spinal column doesn't close properly. It can block the flow of CSF and increase pressure in the brain.
• Chiari malformations: When the cerebellar tissue sits lower than normal. It can block the flow of CSF and increase pressure in the brain. It often develops alongside myelomeningocele.

Acquired hydrocephalus can happen at any age—during birth, shortly after, or much later as an older child or adult. Causes include: 

• Head injuries
• Bleeding in the brain
• Strokes
• Infections like meningitis or encephalitis
• Tumors
• Cysts, including arachnoid (on the brain or spinal cord) and colloid (in the ventricle)

Without treatment, hydrocephalus can cause brain damage and even death. There are effective treatments for this disease. Our goal in treating this condition is to reduce the damage to the brain by helping reduce pressure and improve the flow of CSF.

Medicines

Medicines to treat hydrocephalus include diuretics, which can decrease the amount of CSF made. This can reduce the pressure in the skull. You'll also need antibiotics if you have an infection.

Procedures

Draining CSF with a lumbar puncture can temporarily reduce the pressure in the brain. This procedure can help in some cases of communicating hydrocephalus. Doctors sometimes use this procedure to get an accurate diagnosis.

Surgery

Typically, surgery is our best option to fix hydrocephalus and reduce the risk of long-term complications. 

• Surgical evacuation: We'll go into the brain and remove the blockage. This surgery can help if a hemorrhage, cyst, or tumor is blocking the flow of CSF.
• Endoscopic third ventriculostomy (ETV): This surgery makes a tiny hole at the bottom of the third ventricle to relieve pressure. It's used in some cases of aqueductal stenosis to avoid a shunt.
• Choroid plexus cauterization: A surgeon uses electric current to burn the parts of the brain that make CSF. The brain makes less CSF, reducing the pressure. Surgeons often use this technique alongside ETV.
• Ventricular shunt: This is a flexible tube inserted into the brain to drain CSF into the chest cavity or the abdomen, where the body can absorb it. Often, your surgeon also places a valve to regulate how much CSF drains. Shunts can fail or get infected, in which case you'll need surgery to repair or replace them.
• Venous sinus stenting: This is a potential treatment for idiopathic intracranial hypertension. A tube widens the venous sinuses, which collect blood from the brain and return it to the heart. 

Therapies

Even after effective treatment, many people with hydrocephalus may need rehabilitation therapies. They may need additional support from:

• Physical, occupational, speech, and developmental therapists
• Special education teachers for children with learning disabilities
• Mental healthcare professionals or social workers
• Specialists in dementia care for older adults