Normal Aging vs. Alzheimer’s: Understanding the Differences

UNDERSTANDING DEMENTIA

Normal Aging Versus Alzheimer's Disease

Short-term memory loss is an early indication of possible dementia. But early on, there are doubts because all of us experience memory losses over time. It is important to understand that normal aging has its own set of problems. Following is a short summary of “Brutal Truths About the Aging Brain,” an article by Robert Epstein published in Discover Magazine.

“Normal aging has a devastating effect on our ability to learn and remember, on the speed with which we process information, and on our ability to reason.”

Between the teen years and old age, the loss of brain volume caused by atrophy is 15 percent or more.

More importantly, there is a loss in the network of connections between brain neurons and a decline in dopamine, the chemical involved in transmitting signals.

The four cognitive systems that decline as we age are:

(1) Sensory capability (vision, hearing, touch, smell, and taste): The sensory decline results in greater difficulty maintaining focus/concentration and a reduced ability to easily interact with the world around us.

(2) Memory capacity (immediate memory, working memory): The ability to process new information is compromised. Over an extended period, some long-term memories become cloudy or fade away and word recall declines steadily. (Example: A review of B.F. Skinner’s recorded debates showed that his speech rate declined from 148 words per minute when he was 58 to 106 words per minute when he was 86.)

(3) Knowledge: The degradation of sensory and working memory systems reduces our ability to transfer new information into long-term storage.

(4) Intelligence: Raw scores on intelligence tests peak when we are young (teens and twenties) and decline throughout our adult lives. While factual information stays strong into our sixties, reasoning ability slows down more rapidly.

“The deterioration of these four systems appears to be an inevitable part of normal, healthy aging, although the rate of decline varies among individuals.”

The ability to easily process information declines more rapidly than all other mental capabilities.

While brain aging is natural and inevitable, there is a distinct difference between normal brain aging and dementia.

Characteristics of Normal Brain Aging

A decline in learning capabilities

Reduced speed in processing information

A more limited ability to reason

Increased difficulty concentrating, particularly when there are distractions

Forgetting people’s names and remembering them later

Difficulty finding the right words on a timely basis

Misplacing things and retracing steps to find them

A reduced ability to multitask

Despite these limitations, people who experience normal brain aging can live full, productive, and rewarding lives. They just do not have the relative advantages of youth.

Characteristics of Alzheimer’s Disease

Alzheimer’s Disease is the largest cause of dementia, accounting for about 70 percent of all cases. It is an impairment of cognitive functions beyond those due to normal aging and may include a disturbance of memory, thinking, learning, language, judgment, orientation and comprehension, accompanied by problems with control of emotions and behavior. There are several other causes of dementia, including Parkinson’s disease, Huntington’s disease, blood vessel damage, and traumatic brain injuries, and each case presents its own set of symptoms. Dementia may be progressive or static. Alzheimer’s disease is progressive, cannot be cured, and is characterized by:

Short-term memory loss initially, followed by long-term memory loss

Asking the same questions repeatedly

Losing track of the day, date, and time

Placing things in unusual and unexpected places

Difficulty distinguishing reality from imagined reality

Trouble with decision-making

Confusion, resulting in feelings of anxiety, sorrow, or fear

Difficulty carrying out everyday activities (e.g., bills, appointments)

Problems with planning and understanding instructions

Forgetting names of close friends and relatives

Poor judgment

Wandering and a tendency to get lost

Deteriorating social interactions and body functions

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