Your brain ventricles are four fluid-filled chambers that produce cerebrospinal fluid. This fluid helps nourish your brain and protect it from injury.
It would be easy to argue that your brain is the most important organ in your body since it controls all your conscious thoughts and unconscious actions, like breathing and swallowing.
When you picture the human brain, you may be picturing a solid lump of wrinkly, grey tissue, but your brain actually contains several hollow cavities called ventricles.
These ventricles play a crucial role in maintaining the health of your central nervous system. Several medical conditions affecting your ventricles, like infections or hydrocephalus, can be life-threatening.
Keep reading as we review the function and structure of your brain ventricles as well as health conditions that can affect them.
As we mentioned, ventricles are hollow cavities in your brain. A special network of tissue that lines their surface, called the choroid plexus, produces cerebrospinal fluid that circulates through your brain and spinal cord.
This fluid plays several
- protecting your brain and spinal cord from injury
- reducing the effective weight of your brain through buoyancy (like a cork floating in a container of water)
- delivering essential nutrients to your central nervous system (CNS)
- helping remove metabolic waste from your CNS
Structure
Your brain has four ventricles. Here’s a brief look at each:
- Lateral ventricles: You have one large lateral ventricle on either side of your brain. They’re C-shaped and can hold about
10 millilitres of fluid each. - Third ventricle: The third ventricle is a funnel-shaped cavity between structures called the thalamus and hypothalamus near the center of your brain. It’s smaller than the lateral ventricles.
- Fourth ventricle: The final ventricle is the smallest and is located in your brainstem, the region at the back of your brain where it connects to your spinal cord.
Hydrocephalus is one of the most common disorders affecting the ventricles of the brain. It develops when fluid builds up inside the ventricles, usually due to a blockage.
In infants, hydrocephalus is often caused by a congenital malformation of the brain that narrows the channels that allow fluid to flow in and out of the ventricles.
Symptoms of hydrocephalus
- rapid increase in head size
- unusually large head
- bulge in the soft spot of the head
- feeding problems
- irritability
- sleepiness
- seizures
- slowed development
In children old enough to speak or adults, they may complain of symptoms such as:
- headache
- blurred or double vision
- inability to turn eyes outward
- nausea or vomiting
- balance problems
- vision problems
- poor coordination
- difficulty walking
- memory issues
Causes of hydrocephalus
Any condition that blocks fluid flow through the brain can lead to hydrocephalus. Potential causes include:
- meningitis
- stroke
- head trauma
- brain tumors
- surgical complications
- reduced reabsorption of fluid by specialized structures called arachnoid villi
Hydrocephalus is a medical emergency. It’s often treated surgically with a minimally invasive procedure to insert a shunt. This shunt keeps the channels between your ventricles open and helps excess drain cerebral spinal fluid.
Less commonly, some people receive medications to reduce cerebrospinal fluid production.
Types of hydrocephalus
Hydrocephalus can be divided into four primary types:
- Normal pressure hydrocephalus: When fluid builds up slowly enough that the fluid pressure inside your ventricles doesn’t increase. It’s
most common in older adults. - Communicating hydrocephalus: Occurs when fluid is blocked after leaving the ventricles, which prevents reabsorption.
- Obstructive hydrocephalus: When
a blockage prevents fluid from flowing between your ventricles. - Hydrocephalus ex-vacuo: When stroke or injury causes brain tissue around the ventricle to shrink, and the ventricle grows. It’s generally considered a hydrocephalus
mimic versus a type of hydrocephalus itself.
In addition to hydrocephalus, the following potential disorders can also affect the ventricles of the brain.
Ventriculomegaly (ventricular enlargement)
Ventriculomegaly is the enlargement of the ventricles in the brain. It’s often caused by genetic conditions or as a complication of hydrocephalus.
Minor cases might not cause problems, but severe cases may cause brain development problems. It’s often identified in infants before birth with a prenatal ultrasound.
Treatment is usually only required if signs of hydrocephalus are present. The typical treatment is a shunt to prevent fluid build-up
Ventricular hemorrhage
Ventricular hemorrhage is bleeding into your ventricles. It primarily affects premature infants born in fewer than
In adults, high blood pressure is thought to be a major risk factor. This bleeding can lead to post-hemorrhagic hydrocephalus, which can be life-threatening.
Treatment may include:
- surgery to temporarily drain fluid from the ventricles
- drugs to dissolve blood clots
- surgical shunts, for severe cases
- addressing causes of high blood pressure
Ventriculitis
- fever
- altered mental status
- headaches
- nausea
Ventriculitis requires immediate treatment to avoid hydrocephalus or other potentially lethal complications.
Bacterial infections are
Congenital conditions
Some genetic conditions can lead to malformation of the brain’s ventricles and increase the risk of hydrocephalus. Two examples include X-linked hydrocephalus syndrome and Dandy-Walker malformation.
X-linked hydrocephalus syndrome is a recessive condition caused by mutations on the X sex chromosome. It’s characterized by:
- enlarged ventricles
- a high risk of hydrocephalus
- varying degrees of intellectual disability, as a complication of hydrocephalus
Dandy-Walker syndrome is a rare condition that occurs in about
Dandy-Walker syndrome is also associated with other malformations of the brain.
Your ventricles are key structures in your brain that produce cerebrospinal fluid. This fluid helps lessen the effective weight of your brain inside your head, provides your brain with essential nutrients, and carries away waste.
If the channels that let fluid flow out of your ventricles become blocked, you can develop a serious condition called hydrocephalus.
Hydrocephalus is a medical emergency that requires prompt medical attention, where fluid builds up in your ventricles and puts pressure on your brain.