Hydrocephalus is described as a neurological condition when cerebrospinal fluid (CSF) builds up in the cavities of the brain and causes the brain to swell. Cavities are the hollow places inside the brain known as ventricles. Usually, CSF circulates through the ventricular system of the brain and is absorbed into the bloodstream. Hydrocephalus occurs when there is a disproportion between the amount of CSF produced and the rate at which it is absorbed. AS CSF builds up, it causes expansion of the ventricles and increases pressure inside the brain. Too much pressure can damage the brain tissue and may lead to a range of impairments in brain function, which can happen to anyone, however, infants and people above 60 years are at higher risk.
CSF plays a vital role in brain functioning, such as protecting the nervous system, waste removal, providing nourishment to the brain, cushioning the brain from injury, etc. The brain produces approximately 500 ml CSF per day. Old cerebrospinal fluid is absorbed into the tissues, and the brain is filled with new CSF. If this cycle of production and removal gets disturbed, it might lead to hydrocephalus.
Symptoms of hydrocephalus
Sign and symptoms of hydrocephalus vary with different age groups.
In older adults include:
What causes hydrocephalus?
Cerebrospinal fluid is produced by the ventricular tissues of the brain. It flows through the ventricles via interconnecting channels. In normal condition, fluid flows into spaces around the brain and spinal column. It is primarily absorbed by blood vessels. However, when there is a disturbance between the production and absorbance rate of CSF, it may result in hydrocephalus.
There can be various reasons for fluid accumulation. Some of them are:
Types of hydrocephalus
Hydrocephalus has several types:
1. Congenital Hydrocephalus- There is an excess of CSF accumulation at birth. It might be the result of any infection or trauma during fetal development.
2. Acquired Hydrocephalus- This develops after birth, usually caused by stroke, brain tumor, cyst, or meningitis.
3. Normal Pressure Hydrocephalus (NPH)- It is more common in people older than 55 years. Stroke, injury, infection, surgery, or hemorrhage are possible causes of NPH. It leads to swelling in small, open areas of the brain but does not cause any change in pressure.
4. Communicating Hydrocephalus- Also known as non-obstructive hydrocephalus. It occurs when CSF flows out of ventricles into the spinal cord, but it does not get reabsorbed by the brain and spinal cord tissue.
5. Non- communicating hydrocephalus- Also known as obstructive hydrocephalus. It occurs when CSF does not flow adequately between or out of the brain. This happens when the connection between ventricles becomes blocked.
6. Hydrocephalus ex-vacuo- This kind of hydrocephalus occurs when brain tissue begins to shrink, and ventricles become large. This may happen due to any traumatic injury, stroke, or degenerative disease.
There are several factors that contribute to the severity of hydrocephalus. How hydrocephalus develops and how it progresses play a major role in the severity of this ailment. If hydrocephalus is advanced by the time of birth, it may result in intellectual and physical dysfunction. However, less serious cases, when treated timely, give a much better outlook. Newborns with congenital hydrocephalus may encounter some permanent damage in the brain, leading to some long-term complications such as:
Adults with hydrocephalus may experience a consequential decline in memory and thinking skills with low recovery rates.
Diagnosis of hydrocephalus
If an individual is suspected of hydrocephalus, a healthcare provider can diagnose it based on:
General physical examination
In a general physical exam, doctors look for signs and symptoms like sunken eyes, slow reflexes, bulging fontanel, or head enlargement.
A neurologist performs neurological tests depending on the person’s age. Patients may be asked simple questions to rule out muscle conditions, movements, how well senses are functioning, and mental conditions.
Brain imaging scans
1. Ultrasound- It uses high-frequency sound waves to produce images of the scanned part. This type of scan is usually performed in babies whose fontanel is still open. Ultrasound is also used to detect hydrocephalus before birth when the test is performed as a prenatal examination.
2. MRI Scan- Magnetic Resonance Imaging utilizes radio waves and magnetic fields to create cross-sectional images of the brain. MRI is a completely non-invasive and painless procedure that allows a doctor to visualize any abnormality within the body. The scan can show enlarged ventricles that might be caused by excessive accumulation of cerebrospinal fluid.
3. CT Scan- The scan uses X-ray technology to create 3-D images of the brain, which can show ventricular enlargement and other changes inside the brain.