What condition is characterized by an excess of cerebrospinal fluid?

Hydrocephalus is characterized by an accumulation of cerebrospinal fluid (CSF) within the ventricles of the brain, leading to increased intracranial pressure. This condition can result from various factors, such as obstruction of CSF pathways, overproduction of CSF, or issues with absorption. The excess fluid causes the ventricles to enlarge, which can lead to symptoms such as headaches, nausea, cognitive difficulties, and in severe cases, can result in brain damage if not treated.

Other conditions listed do not specifically involve excess cerebrospinal fluid accumulation. For example, subarachnoid hemorrhage is typically a bleeding event that may actually lead to reduced CSF flow rather than excess. Anencephaly refers to a developmental condition where significant portions of the brain and skull are absent, not associated with an increase in CSF. Multiple sclerosis is a neurological disorder involving inflammation and damage to the myelin sheath in the central nervous system, but it does not primarily cause excess cerebrospinal fluid.