What is Hydrocephalus?
Hydrocephalus refers to the symptomatic accumulation of cerebrospinal fluid (CSF) inside the brain’s ventricles, known as cerebral ventricles. The brain and the spinal cord are surrounded by this fluid, as evident from its name. The smooth flow of CSF gets obstructed in its circulatory path due to the accumulation of abnormal production of the fluid. Problems owing to its absorption into the venous system by the Pacchionian arachnoid granulations is another reason behind the obstruction.
These incidences cause the ventricles to get enlarged, leading to an increase of the pressure inside the head. This results in the development of this health condition, Hydrocephalus loosely translates to ‘water on the brain’. It is usually more prevalent among individuals above the age of 60 years, although it can occur in children and young adults also.
Types of hydrocephalus
In early 1913, hydrocephalus was classified as communicating and non-communicating hydrocephalus. As hydrocephalus treatment progressed, so did the discovery of its varied types. Let’s broadly discuss the types of the health condition, based on its causes:
Communicating hydrocephalus: This occurs when the cerebrospinal fluid gets blocked after it leaves the ventricles. The word ‘communicating’ is derived from the fact that the fluid can still continue to flow between the ventricles.
Non-communicating or obstructive hydrocephalus: This type of medical condition arises when the flow of the fluid is blocked around one or more of the slender passages that connect the ventricles. One of the leading hydrocephalus causes is the narrowing of the aqueduct of Sylvius, the passage connecting the third and fourth ventricles in the middle of the brain.
Normal-pressure hydrocephalus (NPH): This is a type of communicating hydrocephalus, resulting from tumour, head trauma, infection, subarachnoid haemorrhage, or complications in surgery. However, this condition can occur due to factors that are yet to be discovered. In such incidences, the condition is referred to as idiopathic normal pressure hydrocephalus. It mostly affects the elderly, although it can occur to individuals across ages.
Congenital hydrocephalus: When the medical condition is present at birth, it is termed as congenital or developmental hydrocephalus. This can be acquired or develop during foetal growth or occur due to genetic abnormalities, or spinal dysraphism. In rare cases, the condition may be asymptomatic during childhood, that is, not show any symptoms. However, in such cases, it manifests itself when the individual turns into an adult. This may be closely related to aqueductal stenosis.
Acquired hydrocephalus: As opposed to congenital hydrocephalus that occurs during foetal development, this condition occurs later. It may be the result of another medical condition or an injury and may affect individuals across ages. Premature infants born before the completion of 34 weeks or weigh less than 4 pounds are at a greater risk of bleeding of blood vessels in the brain. Several bleeding may result in acquired, communicating or non-communicating hydrocephalus, defined by the location and extent of the bleeding.
Hydrocephalus ex-vacuo: This develops as a result of stroke or degenerative diseases like dementia and Alzheimer’s, or due to traumatic cerebral injuries. Such incidences cause the cerebral tissue to shrink, resulting in this medical condition.
There are various symptoms of the medical condition. Not all of them may manifest in every individual with the condition. The probable symptoms of the medical condition are as below:
- Difficulty in walking or abnormal gait
- Impaired bladder control
There are certain symptoms of the health condition that are more typical to children and adults than infants, and vice versa. Possible symptoms among children and adults:
- Difficulty in walking, imbalance
- Personality changes, irritability
- Decrease in mental agility
Symptoms more prevalent in infants are:
- A large head that is growing at an abnormally rapid pace
- Developmental delays
- A bulging, soft area a the top of the head, also known as anterior fontanelle
- Poor feeding, Vomiting
- Eye gaze changes – “Sunset Sign”
Diagnosis of Hydrocephalus
A thorough diagnosis of the symptoms is required to decide on the presence of hydrocephalus and the necessary hydrocephalus treatment. The following procedure is generally followed for accurate diagnosis:
- Physical/neurological examinations: The physician may examine the patient physically to assess the symptoms. He/she will enquire about the patient’s medical history. He/she may refer the patient to a neurologist and/or neurosurgeon for undergoing certain medical tests.
- Medical tests: Based on the external manifestations, the physician is likely to recommend the following diagnostic tests to analyse the medical condition, its type and extent. The following are the tests that may be recommended:
- Imaging tests: Imaging tests like MRI (magnetic resource imaging) and CT (computed cryptography) scan help in generating images of the brain to detect the presence, exact location and extent of enlarged brains.
- Cerebrospinal (CSF) tests: This test may be prescribed to analyse where shunt treatment is necessary for the patient. Shunt treatment is one of the most common hydrocephalus treatment methods. These tests include external lumbar drainage assessment, lumbar or spinal tap, and measurement of resistance of CSF outflow.
- Prenatal ultrasound: This test diagnoses the presence of a congenital condition of the disease if it has already not been diagnosed during infancy or early childhood. In most cases, the congenital condition is detected when the head of the infant grows at an abnormal rate or is larger as per his/her weight or height. If the anterior fontanelle is still open, this test can also determine whether hydrocephalus is the reason behind the head being larger than usual. If the ultrasound test result indicates the same, more tests are likely to be recommended for correct analysis of the medical condition.
Hydrocephalus treatment is determined based on the type and severity of the medical condition. The following are the probable methods of hydrocephalus treatment:
Medications: Medications can be perceived as a short-term treatment, although it is not as effective in treating the condition efficiently. It can only be prescribed for impeding the production rate of CSF temporarily.
Shunt treatment: One of the most common long-term treatments is considered to be the shunt treatment. This involves making a hole in the skull and inserting a tube called a shunt into one of the brain cavities. This aids in draining the excess fluid out of the brain. The shunt is diverted to another part of the body, for example, the abdomen, where the fluid can be absorbed.
Among children, the shunt has to be replaced at certain intervals to suit his/her physical development. It may also have to be replaced if the patient develops an infection due to the shunt or it gets blocked.
Endoscopic Third Ventriculostomy: This hydrocephalus treatment may be recommended to patients with the obstructive type of the medical condition. Here, the neurosurgeon makes an incision at the location of the blockage of CSF. This also serves the purpose of draining out the excess fluid from the brain.
Surgical repair: In incidences of congenital hydrocephalus, a surgical repair may be conducted before birth while the foetus is still developing in the uterus.