Senility, dementia, senile dementia, SDAT (senile dementia--Alzheimer's type)---these are terms that are often used interchangeably for Alzheimer's disease. But all dementias are not created equal. While they may have symptoms in common, some dementias can be halted or even reversed and some cannot. Dementia caused by malnutrition, dehydration or depression can be reversed, but Alzheimer's cannot be halted or reversed. It is fatal, and it is the seventh-leading cause of death in America.
What is Senility?
Senile dementia is a term commonly used to describe Alzheimer's. The word "senile" comes from the Latin "senilis," meaning "advanced in age." We use the term to describe things characteristic of later life, usually after the age of 65. In the past, senility was considered the "normal" forgetfulness and confusion associated with the aging process, but now a majority of those diagnosed with senility (60 to 70 percent) are considered to have fatal Alzheimer's dementia. Alzheimer's cannot be definitively diagnosed, though, until after death and microscopic examination of brain tissue.
What is Dementia?
The term "dementia" actually refers to a group of symptoms that may include memory loss, poor judgment or confusion. The symptoms are caused by a person's underlying disease or condition, such as Alzheimer's disease, Parkinson's disease, stroke or tumor, among others. Many forms of dementia are progressive, with ongoing deterioration of cognitive and intellectual functioning, memory, behavior and personality. Eventually, dementia may be accompanied by more obvious physical manifestations, such as loss of bodily functions.
There are three types of Alzheimer's. Familial type is rare, begins early and affects less than 1 percent of sufferers. Early-onset type is diagnosed before age 65 and may even begin in the 30s, 40s or 50s. Late-onset type is diagnosed after age 65. Ninety percent of Alzheimer's sufferers have late-onset type. Damage to the brain, however, may begin 10 to 20 years before any indication of trouble. Abnormal protein clumps called amyloid plaques and twisted protein fibers called neurofibrillary tangles are thought to interfere with the function of neurons in the brain, causing them to be initially less efficient, then to quit working altogether, then to die. This process spreads throughout the brain.
Other Causes of Dementia
The other 30 to 40 percent of dementia sufferers have dementia caused by multiple tiny brain infarcts, or strokes; dementia caused by other diseases such as Parkinson's or Huntington's; or dementia caused by thyroid abnormalities, depression, anemia, infectious viruses, dehydration, alcoholism or even vitamin deficiency. Doctors will try to rule out all these other causes before coming to a diagnosis of possible or probable Alzheimer's disease.
Risk Factors for Alzheimer's Disease
Age is the No. 1 risk factor for dementia due to Alzheimer's. Five percent of people between 65 and 74 have Alzheimer's, with the risk doubling every five years after age 65, according to the Alzheimer's Association. After age 85, the risk of developing the disease is almost 50 percent. You are more at risk if a family member has it or if you've had a serious head injury. There may be a heart-health connection; you are more at risk for Alzheimer's if you have heart disease, high blood pressure, high cholesterol, poorly-controlled diabetes or stroke.