Hydrocephalus is a medical term coined from the Greek words hydro for 'water' and cephalus for 'head'. Previously known as water in the head disease, hydrocephalus is an incurable neurological disorder characterized by excessive accumulation of cerebrospinal fluid (CSF) in the four ventricles of the brain. CSF is an essential fluid that surrounds the spinal cord and brain. It performs three vital functions: to control the amount of blood flow within the brain; to carry nutrients and proteins to the brain while eliminating waste; and to cushion the brain from any shock. Once CSF is produced, it flows normally through narrow pathways connecting the four ventricles and then exits at the base of the brain before being absorbed immediately into the bloodstream.
Hydrocephalus happens when either the production or absorption of CSF is disturbed, obstructing CSF from flowing naturally. Consequently, CSF builds up, resulting in abnormal expansion of the ventricles and thus increasing pressure on the brain tissues. Prolonged CSF pressure affects blood supply to the brain and interferes with the brain's ability to perform normal functions. Undiagnosed and untreated, this condition can impair thought, learning abilities, and coordinated skill movements.
Hydrocephalus primarily affects children. It is diagnosed in one out of every 500 births and falls within one of these two categories:
1. Congenital or Acquired
Congenital hydrocephalus is already present at birth. It can be due to genetic predisposition or environmental factors such as infections and prenatal hemorrhaging, or bleeding in the fetus, during fetal development. Meanwhile, acquired hydrocephalus appears during birth or is detected later. This type results from diseases like meningitis, tumors and cysts. Injuries and trauma to the head can also bring about this condition.
2. Communicating or Non-Communicating
Communicating hydrocephalusis a state in which CSF flows normally between the four ventricles, but is blocked after it exits them. Contrary to this,
non-communicating hydrocephalus, or obstructive hydrocephalus, exists when CSF flow is hindered along the narrow pathways between the ventricles.
The incidence of hydrocephalus among adults is currently unknown. However, each case falls into one of the two types below:
3. Normal Pressure Hydrocephalus (NPH)
NPH is common among people over 55 years of age. The primary cause of NPH is trauma to the head, such as infection and bleeding within the brain. In this case, even though the ventricles are enlarged, pressure within the brain remains unchanged. Left untreated, NPH will eventually lead to memory loss, or dementia.
4. Hydrocephalus ex-vacuo
This condition can occur in people of any age. It arises when there is severe damage to the brain, such as a traumatic injury or a stroke. These injuries shrink brain tissues, allowing the presence of too much CSF in the ventricles while maintaining a normal amount of pressure in the brain. Though this disorder is irreversible, it does not pose a health danger and therefore does not require treatment.
It is crucial to diagnose and treat hydrocephalus as early as possible to minimize or prevent the development of other long-term problems affecting learning and physical abilities.