It can be surprising to realize that an organ as high-powered and sophisticated as the brain also has a plumbing system. And, as the case with a house’s plumbing, the drainage side of the system can get gummed up. But the symptoms are different. When a home’s drainage backs up, well…I won’t go there. When the brain’s drainage system backs up, the brain’s owner can become confused, incontinent of urine and unsteady on his or her feet.
The plumbing system in question is that which produces and drains the cerebrospinal fluid (CSF). Normal CSF looks the same as water from a faucet, but is created from the bloodstream in the choroid plexus tissue within three of the brain’s four inner chambers — the right and left “lateral” ventricles and the midline “fourth” ventricle, but not the interposed, midline “third” ventricle. The CSF percolates through passageways from one ventricle to another, finally emerging through openings at the base of the brain to bathe the outer surfaces of the brain and spinal cord before getting reabsorbed into the bloodstream again. This re-absorption occurs in special...