Hydrocephalus is best described as?

• A. A degenerative brain disease
• B. A condition where CSF builds up in the ventricles, causing increased pressure on the brain
• C. A temporary decrease in CSF production
• D. A bacterial infection of the meninges

Answer: (B)

Hydrocephalus means cerebrospinal fluid (CSF) is not flowing or being absorbed properly and ends up building up in the brain’s ventricular system, which raises the pressure inside the skull. Normally CSF is produced and circulated around the brain and spinal cord and then absorbed into the bloodstream. If a blockage, impaired absorption, or overproduction occurs, fluid accumulates in the ventricles, making them enlarge and pressing on brain tissue. That combination—CSF accumulating specifically in the ventricles and the resulting increased intracranial pressure—is the defining feature of hydrocephalus.

This is not simply a degenerative brain disease, nor is it a temporary drop in CSF production or an infection of the meninges. The latter would be meningitis, which is a different condition.