Hydrocephalus is a neurological condition characterized by the accumulation of cerebrospinal fluid (CSF) within the ventricles of the brain. This build-up of fluid can cause increased pressure inside the skull resulting in damage of brain tissue, leading to a range of neurological symptoms and complications. Hydrocephalus can occur at any age, but it is more commonly seen in infants and older adults. There are two primary forms of hydrocephalus: congenital (present at birth) and acquired (develops later in life).

---

2. Causes

Hydrocephalus can be caused by various factors, which include:

1. Congenital factors: Genetic mutations or developmental abnormalities during fetal development can lead to congenital hydrocephalus.
2. Acquired factors: Head injuries, brain tumors, infections (such as meningitis), or bleeding in the brain (due to hemorrhagic stroke) can cause acquired hydrocephalus.
3. Obstructive hydrocephalus: This type results from a blockage in the flow of CSF within the ventricles, leading to fluid accumulation.
4. Communicating hydrocephalus: This form occurs when there is an issue with the absorption of CSF, even though the flow of fluid is not blocked.
5. Normal pressure hydrocephalus (NPH): More common in older adults, NPH is characterized by the abnormal accumulation of CSF without a significant increase in intracranial pressure.

---

3. Epidemiology

The prevalence of hydrocephalus varies depending on the population and the cause of the condition. Congenital hydrocephalus affects around 1 in every 1,000 live births. Acquired hydrocephalus and NPH are more common among older adults. The overall incidence of hydrocephalus is estimated to be 1-1.5 cases per 1,000 individuals.

---

4. Symptoms

The symptoms of hydrocephalus can differ based on the individual’s age and the severity of the condition. Some common symptoms include:

Infants: Abnormally large head, bulging fontanelles (soft spots), vomiting, irritability, seizures, poor feeding, and developmental delays.

Children and adults: Headaches, nausea, vomiting, blurry or double vision, difficulty walking or poor balance, memory problems, changes in personality or cognitive function, and incoordination.

Normal pressure hydrocephalus: Difficulty walking (shuffling gait), urinary incontinence, and memory loss or dementia.