What does hydrocephalus indicate?

Hydrocephalus specifically refers to a condition characterized by an increased accumulation of cerebrospinal fluid (CSF) within the brain's ventricles. This buildup can lead to increased intracranial pressure, which may cause various neurological symptoms. In healthy individuals, CSF is produced and absorbed continuously, maintaining a stable pressure and providing cushioning and support for the brain. When this balance is disrupted, as seen in hydrocephalus, the excess fluid can cause the ventricles to enlarge, potentially leading to serious complications.

The other choices relate to different conditions or phenomena that do not accurately define hydrocephalus. For example, increased blood pressure in the brain might indicate hypertension or hemorrhage but does not specifically describe the fluid accumulation aspect of hydrocephalus. Decreased brain activity focuses on neurological function rather than the physical changes in CSF dynamics, and inflammation of the cerebral cortex pertains to a different pathological process entirely. Thus, the defining feature of hydrocephalus is indeed the increased accumulation of cerebrospinal fluid.