The term hydrocephalus is derived from two words: "hydro" meaning water, and "Cephalus" referring to the head.
Hydrocephalus is a condition in which excess cerebrospinal fluid (CSF) builds up within the ventricles (fluid-containing cavities) of the brain and may increase pressure within the head. Although hydrocephalus is often described as "water on the brain," the "water" is actually CSF, a clear fluid surrounding the brain and spinal cord. CSF has three crucial functions: 1) it acts as a "shock absorber" for the brain and spinal cord; 2) it acts as a vehicle for delivering nutrients to the brain and removing waste; and 3) it flows between the cranium and spine to regulate changes in pressure within the brain. Hydrocephalus can occur at any age, but is most common in infants and adults age 60 and older.
Approximately 1 in every 500 American babies are born with hydrocephalus. It may be caused by an infection in the mother during pregnancy, such as rubella or mumps, or a birth defect, such as spina bifida. It is one of the most common developmental disabilities, more common than Down syndrome or deafness.
This develops after birth, usually after a stroke, brain tumor, meningitis, or as a result of a serious head injury.
This type of hydrocephalus occurs when the CSF becomes blocked after leaving the ventricles. It is called "communicating" because CSF can still flow between the brain's ventricles.
Also called obstructive hydrocephalus, non-communicating hydrocephalus occurs when the thin connections between the ventricles become blocked.
This only affects people aged 50 or older. It may develop after stroke, injury, infection, surgery, or hemorrhage. However, in many cases, doctors do not know why it occurred.
This type occurs after stroke, traumatic brain injury, or degenerative diseases. As brain tissue shrinks, the ventricles of the brain become larger.
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. The fluid 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:
Excess cerebrospinal fluid in the ventricles occurs for one of the following reasons:
The following factors increase the risk of hydrocephalus:
Other conditions that increase the risk include:
symptoms depend on the type of hydrocephalus and the age of the person affected.
Babies born with hydrocephalus (congenital) often have distinctive physical features.
These can include:
Congenital hydrocephalus can also cause:
Congenital hydrocephalus is sometimes picked up before a baby is born during an ultrasound scan.
However, it's usually diagnosed soon after birth during the newborn physical examination. The problem may be suspected if your baby's head is larger than normal.
Hydrocephalus that develops in adults or children (acquired) can cause headaches.
The headache may be worse when you wake up in the morning because the fluid in your brain does not drain so well while you're lying down and may have built up overnight.
Sitting up for a while may improve your headache. However, as the condition progresses, the headaches may become continuous.
Other symptoms of acquired hydrocephalus include:
The symptoms of normal pressure hydrocephalus (NPH) tend to affect older people and usually develop slowly, over the course of many months or years.
NPH has 3 sets of distinctive symptoms. It affects:
See your GP if you have any of the symptoms described below.
The first noticeable symptom of NPH is a change in how you walk (your gait). You may find it increasingly difficult to take the first step when you want to start walking.
Some people have described it as feeling as though they're frozen to the spot. You may also shuffle rather than take proper steps.
As the condition progresses, you may become increasingly unsteady on your feet and be more likely to fall, particularly when turning.
The change in the way you walk is often followed by bouts of urinary incontinence, which may include symptoms such as:
The normal thinking process also starts to slow down. This can take the form of:
These symptoms may indicate that you have mild dementia. They should start to improve when NPH is treated.
There are no effective medicines for hydrocephalus. Most children require surgery. The goal is to lessen the pressure in the brain by providing another pathway for CSF to be drained and absorbed away from the brain.
There are two types of surgery for hydrocephalus:
Both these surgeries are described in detail below.
The most common treatment of hydrocephalus is the surgical placement of a shunt. A shunt is a soft, flexible tube.
The top end of the shunt is placed in the ventricle fluid spaces inside the brain. This tube is attached to a valve that controls the flow of CSF through the shunt. The tube is then tunnelled below the skin to an area of the body where the fluid can be absorbed. One area is the lining of the abdominal cavity (the peritoneum). This is called a ventriculo-peritoneal shunt (VP shunt).
Less often, the shunt is connected from the brain to other parts of the body:
Your child is brought down to the operating room and goes to sleep under general anesthesia. Your child will not feel any pain during the operation.
The area from the head to the abdomen (belly) is scrubbed with a special soap. The surgeon makes incisions (cuts) on the head and abdomen. The shunt tubing is tunnelled just below the skin. The ventricular (top) end of the shunt is passed through a small hole in the skull made by the surgeon and gently passed into the ventricle. The abdominal (bottom) end is passed through a small opening in the abdomen. The incisions are then closed using staples or stitches.
The operation takes between one and two hours.
An endoscopic third ventriculostomy (ETV) is the second type of surgery done on some children who have hydrocephalus. Your surgeon will tell you if this surgery is possible for your child.
During an ETV, the surgeon makes an opening in the floor of the ventricle at the base of the brain. The CSF is then no longer blocked inside the ventricle. Now it can flow in and around the brain as it should.
This means that the child will not need a shunt, but instead will rely on the opening made by the surgeon during surgery. It is still very important to watch your child for signs that the pressure is building up again, as it is possible that the ETV could fail or become blocked. If any signs come back, it is very important to call your surgeon right away so that your child can be checked.
Your child is brought down to the operating room and is put asleep under general anesthesia. Your child will not feel any pain during the operation. An incision is made on the head. A special scope with a camera on it is passed into the ventricle. The surgeon uses the camera to see the part of the ventricle that needs to be opened up. Once the opening is made, the surgeon will be able to see if the CSF is now flowing outside of the ventricle.
If the surgeon is not able to safely do the ETV, a shunt will be inserted instead. The incisions are then closed using staples or stitches.
The operation takes between one and two hours.
Your child is then taken to the Post Anesthetic Care Unit (PACU) recovery room. Your child will wake up soon after the operation. You will be able to see your child as soon as he wakes up. Your child will spend about one to two hours in the PACU to recover from the anesthetic. Then your child will be returned to his room in the neurosurgical unit.
Your child will have a bandage on the head. If your child received a shunt, they will have another bandage on the abdomen or chest, depending on the type of shunt.
The nurse will check your child often. They will also be checking to see how easily your child wakes up, even at night.
Your child will have an intravenous (IV) line after surgery until they are drinking well.
Your child may have a CT scan after surgery to make sure the ventricles have decreased in size and, if your child needed a shunt, that the shunt is in a good position.
Both surgical procedures can result in complications. Shunt systems can stop draining cerebrospinal fluid or poorly regulate drainage because of mechanical malfunctions, blockage or infections. Complications of ventriculostomy include bleeding and infections.
Any failure requires prompt attention, surgical revisions or other interventions. Signs and symptoms of problems may include: