Hydrocephalus

The accumulation of fluid in the cavities (ventricles) deep within the brain is known as hydrocephalus. The extra fluid causes the ventricles to enlarge, putting pressure on the brain. The cerebrospinal fluid (CSF) that travels through the ventricles bathes the brain and spinal column. However, excessive cerebrospinal fluid pressure, which is associated with hydrocephalus, can damage brain tissues and cause a variety of brain function problems. Hydrocephalus can strike anyone at any age; however, it is more common in infants and individuals aged 60 and above. Hydrocephalus can be surgically treated to restore and maintain normal cerebrospinal fluid levels. Managing symptoms or problems caused by hydrocephalus often require a variety of treatments.

Communicating Hydrocephalus: Full communication between the ventricles and the subarachnoid space (a CSF-filled region) causes communicating hydrocephalus. It is caused by excessive CSF production (rarely), defective CSF absorption (most often), or venous drainage insufficiency (occasionally).

Non-communicating/Obstructive Hydrocephalus: CSF flow within the ventricles or between the ventricles and the subarachnoid space is obstructed.

Normal Pressure Hydrocephalus (NPH): It can be caused by bleeding in the CSF of the brain (subarachnoid or intraventricular hemorrhage), head trauma, tumor, infection, or a surgical complication. Even if none of these conditions are present, many people develop NPH. 

Hydrocephalus ex-vacuo: It occurs due to brain damage caused by a stroke or an injury. The brain tissues surrounding the ventricles shrink, resulting in enlargement of the ventricles.

An imbalance between the amount of cerebrospinal fluid produced and the amount absorbed into the blood causes hydrocephalus. The tissues that line the ventricles of the brain produce cerebrospinal fluid. In the ventricles, it passes through a series of interconnecting channels. The fluid eventually flows into areas around the brain and spine and is absorbed by blood vessels in tissues on the brain’s surface.

Cerebrospinal fluid is essential for brain function because it:

• Enables the relatively heavy brain to float within the skull by keeping it buoyant.
• Cushions the brain from damage or injury.
• Removes metabolic waste products from the brain.
• Flows back and forth between the brain cavity and the spinal column to maintain a constant pressure within the brain — compensating for changes in brain blood pressure.
• One of the following factors can cause too much cerebrospinal fluid in the ventricles:

Obstruction: A partial blockage of cerebrospinal fluid flow, either from one ventricle to the next or from the ventricles to other spaces. 

Poor absorption: A problem absorbing cerebrospinal fluid is less common. This is often linked to inflammation of brain structures due to injury or disease. 

Overproduction: Cerebrospinal fluid is sometimes produced faster than it can be absorbed.

The signs and symptoms of hydrocephalus vary according to the age at which it first develops: 

Infants

Common signs and symptoms include:

• An unusual large-sized head
• A fast increase in head size
• The top of the head has a bulging or tense soft area (fontanel)
• Vomiting and nausea
• Sluggishness or sleepiness (lethargy)
• Irritability
• Lack of appetite
• Seizures
• Downward-looking eyes (sunsetting of the eyes)
• Muscle tone and strength problems

Toddlers

Signs and symptoms may include:

• Headache.
• Blurry or double vision
• Abnormal eye movements.
• Abnormal increase of head size
• Sluggishness or sleepiness.
• Vomiting or nausea.
• Unstable balance.
• Coordination difficulties.
• Appetite issues
• Bladder control problems or frequent urination
• Irritability
• Personality changes
• Delays or difficulties with previously learned skills like walking or talking

Young Adults

The following are common signs and symptoms in this age group:

• Headache
• Slowness
• Coordination or balance issues
• Frequent urge to urinate or Urinary incontinence or  
• Vision problems
• Memory, thinking skills, or focus may decline, impacting job performance.

Older Adults

In people aged 60 and above, the following are the most common signs and symptoms of hydrocephalus:

• Urinary incontinence
• frequent urge to urinate
• Loss of memory
• Loss of thinking or reasoning skills 
• Difficulty walking
• Coordination or balance problems

Hydrocephalus can be congenital (present at birth) or develop shortly after birth due to any of the following factors:

• A condition in which the central nervous system develops abnormally, obstructing the flow of cerebrospinal fluid.
• Bleeding within the ventricles, a possible premature birth complication
• An infection in the uterus, such as rubella or syphilis, can trigger inflammation in the fetal brain tissues during pregnancy.
• Lesions or tumors in the brain or spinal cord.
• Infections of the central nervous system, such as bacterial meningitis or mumps.
• A stroke or a head injury may cause bleeding in the brain.
• Other types of traumatic brain injury.

Neurological Exam: The type of neurological exam a person receives is determined by their age. In the clinic, the neurologist may ask questions and do simple tests to assess muscle condition, movement, well-being, and the functioning of the senses.

Brain Imaging: The following imaging tests can assist in the diagnosis of hydrocephalus and the identification of the underlying causes of the symptoms:

Ultrasound: As it is a reasonably low-risk and simple procedure, this test is often used for the initial screening of infants. The ultrasound equipment is positioned over a soft spot on the top of a baby's head called the fontanel. During standard prenatal checkups, ultrasound may diagnose hydrocephalus before birth.

MRI: This technique produces comprehensive brain images using radio waves and a magnetic field. Although this test is painless, it is noisy and requires that you lie still. Excess cerebrospinal fluid can show enlarged ventricles, as seen on MRI images. They can also be utilized to figure out what's causing the hydrocephalus or what's causing the symptoms. Some MRI scans may require minor sedation in children. On the other hand, some facilities use a quick version of MRI that doesn't require sedation.

Ct scan: This specialist X-ray technology obtains cross-sectional views of the brain. Scanning is quick and painless. However, because this test requires lying still, a youngster is usually given a mild sedative. CT scanning produces less detailed images than MRI and involves a small level of radiation exposure. CT scans for hydrocephalus are usually reserved for urgent cases. 

Shunt: The surgical insertion of a drainage system, known as a shunt, is the most common treatment for hydrocephalus. It's made up of a long, flexible tube with a valve that keeps brain fluid flowing in the proper direction and rate. The tubing is usually placed into one of the brain's ventricles on one end. The tubing is then tunneled through the skin to a different body part, such as the belly or a heart chamber, where the extra fluid can be absorbed more easily. Hydrocephalus patients typically require a shunt system for the rest of their lives. They must be monitored regularly.

Endoscopic third ventriculostomy (ETV)is a surgical procedure used in some cases. The surgeon examines the inside of the brain with a small video camera. To let the cerebrospinal fluid drain out of the brain, the surgeon makes an opening in the bottom of one of the ventricles or between the ventricles.

Other Surgical Procedures: In some cases, choroid plexectomy, choroid plexus coagulation, and endoscopic cerebral aqueductoplasty have all proved beneficial. In non-communicative hydrocephalus, endoscopic fenestration of the third ventricle floor may be effective, but it is contra-indicated in communicating hydrocephalus.

Hydrocephalus usually progresses, which means that if it isn't treated, it might lead to intellectual, developmental, and physical disabilities. It can potentially be fatal. 

You can't prevent hydrocephalus, but you can reduce your and your child's chances of developing it.

• Make sure you get prenatal care while you're expecting. This can assist you in avoiding going into early labor, which can result in hydrocephalus.
• Vaccinations can help in the prevention of diseases and infections connected to hydrocephalus. Regular tests can help ensure that illnesses or conditions that could put you at risk of developing hydrocephalus are treated quickly.
• When performing activities like riding a bike, use safety equipment like helmets to avoid head injuries. You can also lower your chances of suffering a brain injury by always wearing a seat belt.

Our clinical experts continually monitor the health and medical content posted on CURA4U, and we update our blogs and articles when new information becomes available. Last reviewed by Dr.Saad Zia on May 21, 2023. 

References

Hydrocephalus | National Institute of Neurological Disorders and Stroke (nih.gov)

https://www.ninds.nih.gov/health-information/disorders/hydrocephalus#:~:text=What%20is%20hydrocephalus%3F,pressure%20on%20the%20brain's%20tissues.

Hydrocephalus – Causes, Symptom and Surgical Treatments (aans.org)

https://www.aans.org/en/Patients/Neurosurgical-Conditions-and-Treatments/Hydrocephalus