The cerebrospinal fluid of the neuraxis is regenerated several times every twenty-four hours. Endolymph and perilymph , the fluids of the inner ear, are derived from cerebrospinal fluid. Currently, there is no consensus regarding the manner in which cerebrospinal fluid enters the inner ear. Osmosis may be involved. A condition called hydrocephalus occurs when, for some reason, too much cerebrospinal fluid is produced and the ventricles swell, putting pressure on the tissue of the brain.
Tumors are one potential cause of an over-production of cerebrospinal fluid.
Hydrocephalus should not be confused with hydroencephali . In the past, before CT and MRI technology existed, a technique involving cerebrospinal fluid called pneumoencephalography was used to view the brain. A small amount of cerebrospinal fluid was removed from the ventricular system and replaced with air or some other inert gas. This allowed the examiner to view the ventricles in a scan and make inferences about brain pathology. Tumors and hemorrhages could sometimes be located by examining the shapes and sizes of the ventricles.