For unknown reasons, this condition predominantly affects older adults, according to the Hydrocephalus Association. As fluid builds up in the brain, it stretches nerve tissues, causing difficulty walking, dementia and in later stages, incontinence, which are symptoms usually associated with Alzheimer's and Parkinson's diseases.

Sometimes a brain disease like meningitis can spur the condition, but it often has no known cause, doctors say. It is responsible for about 5 percent of all dementia cases, according to the National Library of Medicine.ABC News:excess fluid in the brain causes alzheimer's symptoms.....MORE..