Alzheimer's Disease: Causes, Diagnosis, Affects, Stages and Statistics


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When was Alzheimer's Disease discovered?

A German doctor named Alois Alzheimer first observed AD in 1906. He described a patient known as Auguste D. who had memory loss and other problems with thinking.

Dr Alzheimer

After the patient’s death, Dr. Alzheimer noted that parts of the patient’s brain were shrunken. A psychiatrist who worked with Dr. Alzheimer named the condition in 1910.


Australian Dementia statistics

  • Dementia is the second leading cause of death of Australians.

  • In 2016 dementia became the leading cause of death of Australian women, surpassing heart disease which has been the leading cause of death for both men and women since the early 20th century.

  • In 2017, dementia remained the first leading cause of death of women, and the third leading cause of death of men. Overall, accounting for 13,729 deaths Females account for 64.5% of all dementia related deaths

  • In 2021, there are an estimated 472,000 Australians living with dementia Without a medical breakthrough, the number of people with dementia is expected to increase to 590,000 by 2028 and 1,076,000 by 2058

  • Currently an estimated 250 people are joining the population with dementia each day. The number of new cases of dementia will increase to 318 people per day by 2025 and more than 650 people by 2056

  • Three in 10 people over the age of 85 and almost one in 10 people over 65 have dementia

  • In 2021, there were an estimated 28,300 people with younger onset dementia, expected to rise to 29,350 people by 2028 and 41,250 people by 2058

  • An average of 36 people died per day where dementia was the underlying cause of death in 2016. Of the 13,126 people that lost their lives, 8,447 were female

  • In 2021, it is estimated that almost 1.6 million people in Australia are involved in the care of someone living with dementia

Source for Current Dementia Statistics: Dementia.org.au



What is Alzheimer's Disease?

15 July 2021

Alzheimer’s disease is a form of dementia that causes changes in memory, thinking, and behavior. Dementia is an umbrella term used to describe any condition that causes problems with memory and thinking that impact a person’s ability to function.

Over time, Alzheimer’s can often progress and impact all aspects of a person’s daily activities. There is currently no cure, but there are treatments that can help with symptoms.

What is Alzheimer's Disease?

What causes Alzheimer’s disease? Plaques and Tangles

Experts do not yet know exactly what causes Alzheimer’s disease. Research has indicated that Alzheimer’s may develop over time due to a number of causes. For example, experts believe that Alzheimer’s disease may be caused by two changes in the brain – plaques and tangles. Plaques are protein clumps. Tangles are twisted fibers. Plaques and tangles form in the brain, and may block or slow communication between nerve cells.

Experts have also identified other potential causes such as age, family history, genetics, environmental issues, and lifestyle. Alzheimer’s may be related to certain conditions such as heart disease, high blood pressure, diabetes, stroke, and obesity.

Who gets Alzheimer’s disease?

Alzheimer’s disease is a common, but devastating disease. It is much more common in older adults.


What are the symptoms of Alzheimer’s Disease?

Alzheimer’s disease can affect each person differently. The most common early symptom is difficulty remembering new information. This is also called short-term memory loss (STML).

As Alzheimer’s Disease progresses, other symptoms can include:

  • confusion about people, places, and time
  • restlessness and wandering
  • changes in mood and behavior
  • suspicious thoughts
  • difficulty understanding the spoken word (receptive aphasia)
  • speech problems (expressive aphasia)
  • confusion about the purpose of objects
  • agitation
  • problems with walking, or falls
  • difficulty eating and swallowing

What does Alzheimer’s disease affect first?

Early signs of Alzheimer's disease will be an ongoing pattern of forgetting items. This starts to affect a person's daily life. He or she may forget where the local store is or the names of close family and friends. This stage may last for some time or get worse quickly, causing more severe memory loss and forgetfulness.

How is Alzheimer’s disease treated?

Alzheimer’s disease is complex, and so medical professionals usually choose to approach treatment from many different angles. Current treatments aim to help people maintain mental function, manage behavioral symptoms, and slow the symptoms of the disease. There are currently four approved drugs available for the treatment of Alzheimer’s, and more are under study.

It is very important that Alzheimer’s disease is diagnosed and treated as soon as possible. If you or someone you care about has concerns about memory loss or other symptoms, talk to your healthcare provider right away. Alzheimer’s disease can only be diagnosed through a comprehensive medical evaluation.

Is Alzheimer's Disease Hereditary or Genetic?

Researchers believe there isn't a single cause of Alzheimer's disease. It likely develops from multiple factors, such as genetics, lifestyle and environment. Scientists have identified factors that increase the risk of Alzheimer’s. While some risk factors — age, family history and heredity — can't be changed, emerging evidence suggests there may be other factors we can influence.

Scientists know genes are involved in Alzheimer’s. Two categories of genes influence whether a person develops a disease: risk genes and deterministic genes. Alzheimer's genes have been found in both categories. It is estimated that less than 1% of Alzheimer’s cases are caused by deterministic genes (genes that cause a disease, rather than increase the risk of developing a disease).

Alzheimer's Disease risk factors you may be able to influence

While age, family history and heredity are all risk factors we can’t change, research is beginning to reveal clues about other risk factors we may be able to influence through general lifestyle and wellness choices and effective management of other health conditions.

Head injury: There is a link between head injury and future risk of dementia. Protect your brain by buckling your seat belt, wearing your helmet when participating in sports, and “fall-proofing” your home.

Heart-head connection: Some of the strongest evidence links brain health to heart health. This connection makes sense, because the brain is nourished by one of the body’s richest networks of blood vessels, and the heart is responsible for pumping blood through these blood vessels to the brain.

The risk of developing Alzheimer’s or vascular dementia appears to be increased by many conditions that damage the heart and blood vessels. These include heart disease, diabetes, stroke, high blood pressure and high cholesterol. Work with your doctor to monitor your heart health and treat any problems that arise.

Studies of donated brain tissue provide additional evidence for the heart-head connection. These studies suggest that plaques and tangles are more likely to cause Alzheimer’s symptoms if strokes or damage to the brain’s blood vessels are also present.

Overall healthy aging: One promising line of research suggests that strategies for overall healthy aging may help keep the brain healthy and may even reduce the risk of developing Alzheimer’s and other dementias. These measures include eating a healthy diet, staying socially active, avoiding tobacco and excess alcohol, and exercising both the body and mind.


Who tests for Alzheimer's Disease?

There is no single diagnostic test that can determine if a person has Alzheimer’s disease. GP's (often with the help of specialists such as neurologists, neuropsychologists, geriatricians and geriatric psychiatrists) use a variety of approaches and tools to help make a diagnosis. Although GP's can almost always determine if a person has dementia, it may be difficult to identify the exact cause.

Mental cognitive status tests

Mental cognitive status testing evaluates memory, thinking and simple problem-solving abilities. Some tests are brief, while others can be more time intensive and complex. More comprehensive mental cognitive status tests are often given by a neuropsychologist to evaluate executive function, judgment, attention and language.

Such tests give an overall sense of whether a person:

  • Is aware of symptoms.
  • Knows the date, time, and where he or she is.
  • Can remember a short list of words, follow instructions and do simple calculations.

Mini-Mental State Exam (MMSE) and the Mini-Cog test

The MMSE and Mini-Cog test are two commonly used assessments.

During the Mini-Mental State Exam (MMSE), a health professional asks a patient a series of questions designed to test a range of everyday mental skills. The maximum MMSE score is 30 points. A score of 20 to 24 suggests mild dementia, 13 to 20 suggests moderate dementia, and less than 12 indicates severe dementia. On average, the MMSE score of a person with Alzheimer's declines about two to four points each year.

During the Mini-Cog test, a person is asked to complete two tasks:

  • Remember and a few minutes later repeat the names of three common objects.
  • Draw a face of a clock showing all 12 numbers in the right places and a time specified by the examiner.

The results of this brief test can help a GP determine if further evaluation is needed.


Brain Imaging

A standard medical workup for Alzheimer's disease often includes structural imaging with magnetic resonance imaging (MRI) or computed tomography (CT). These tests are primarily used to rule out other conditions that may cause symptoms similar to Alzheimer's Disease but require different treatment. Structural imaging can reveal tumors, evidence of small or large strokes, damage from severe head trauma, or a buildup of fluid in the brain.

In some circumstances, a doctor may use brain imaging tools to find out if the individual has high levels of beta-amyloid, a hallmark of Alzheimer’s Disease; normal levels would suggest Alzheimer’s is not the cause of dementia.

Imaging technologies have revolutionized our understanding of the structure and function of the living brain. Researchers are studying other brain imaging techniques so they can better diagnose and track the progress of Alzheimer’s Disease.



The Seven Stages of Alheimer's Disease

Prior to Diagnosis: No Dementia

In the first three stages of the seven-stage model, an individual is not considered to have dementia, as the symptoms are commonly associated with typical aging and are not typically noticeable by healthcare providers or family members. This is also known as Pre-clinical Alzheimer’s Disease.

Alzheimer's Disease Stage One: No Impairment

In the first stage, a person with Alzheimer’s disease has no memory impairment with no evident symptoms of dementia. At this stage, Alzheimer’s disease is undetectable. This stage is also sometimes called No Cognitive Decline.

Alzheimer's Disease Stage Two: Very Mild Cognitive Decline

In this stage, a person with Alzheimer’s disease begins to experience the typical forgetfulness associated with aging. They may forget where they left their car keys or their purse. These symptoms are typically not noticed by the individual’s family members or physician.

Alzheimer's Disease Stage Three: Mild Cognitive Decline

Individuals in this stage experience increased forgetfulness as well as slight difficulty with focus or concentration. These symptoms may result in decreased work performance for those in the workforce, or for those who do not hold outside employment, they may experience decreased performance in ordinary household tasks such as cleaning or paying bills. They may get lost or begin to struggle to find the right words in communication.

In stage three, increased forgetfulness and decreased performance are likely to be noticed by the person’s family members. The average duration of stage three is approximately seven years prior to the onset of dementia.

Alzheimer's Disease Early-Stage Dementia

In the first three stages above, an individual is not considered to have dementia. At stage four, however, that changes, and a person is considered to have early-stage dementia. Note that early-stage dementia differs from early-onset dementia or early-onset Alzheimer’s disease, which refers to the onset of clinical symptoms prior to age 65.

Alzheimer's Disease Stage Four: Moderate Cognitive Decline

Stage four comprises what is clinically described as early-stage dementia. A person with early-stage dementia (in stage four of the seven-stage model) will experience increased forgetfulness, often forgetting recent events, as well as difficulty concentrating, difficulty with problem-solving, and difficulty managing finances. They may have challenges when traveling to unfamiliar areas alone, and they may have difficulty performing complex tasks or organizing and expressing thoughts.

People in stage four may also be in denial about their forgetfulness and other symptoms, and as socialization becomes increasingly difficult, they may begin to withdraw from family and friends. In stage four, a healthcare provider can easily identify cognitive decline in an examination and interview with the patient. The average duration of stage four is approximately two years.


Alzheimer's Disease Mid-Stage Dementia

Stage five marks the beginning of mid-stage dementia, which continues through stage six.

Alzheimer's Disease Stage Five: Moderately Severe Cognitive Decline

Major memory deficiencies are present beginning in stage five, and people in this stage of the disease may require assistance with activities of daily living, such as bathing, dressing, and preparing meals. Memory deficits in this stage are severe, with individuals often forgetting prominent bits of information that affect their daily lives – such as their home address or phone number. They may not be able to identify where they are (orientation to place) or what time of day it is (orientation to time). Stage five lasts, on average, one and a half years.

Alzheimer's Disease Stage Six: Severe Cognitive Decline

Also known as Middle Dementia, stage six marks a period in which a person requires substantial assistance to carry out day-to-day activities. They may have little memory of recent events and forget the names of close friends or family members. Many people in stage six have limited memory of their earlier lives and will also have difficulty completing tasks or successfully exhibiting cognitive skills such as counting backwards from 10.

People in stage six may also begin to experience incontinence of bowel or bladder, and speech ability is often diminished. Significant personality changes may also be noticeable at this stage, as individuals may suffer from delusions, anxiety, or agitation. This stage lasts an average of about two and a half years.

Alzheimer's Disease Late-Stage Dementia

The seventh and final stage comprises the final stage in the three-stage model: late-stage dementia.

Alzheimer's Disease Stage Seven: Very Severe Cognitive Decline

Also known as Late Dementia, stage seven is the final stage in the progression of Alzheimer’s disease. At this stage, most people will have lost their ability to speak or communicate. They often require assistance with most of their activities, including toileting, eating, dressing, bathing, and other daily activities, around the clock. Because people in stage seven often lose psychomotor capabilities, they may be unable to walk or require significant assistance with ambulation. This stage lasts an average of two and a half years.

Alzheimer’s disease is a progressive disease that gradually worsens over a period of four to 20 years. On average, however, most people live between four and eight years following diagnosis. The progression of the disease may be different for each individual, but family members and caregivers should familiarize themselves with the typical stages that occur throughout progression. It’s a challenging road to travel for both the person with Alzheimer’s disease and those who love them, but knowing what to expect can help to ease some stress and uncertainty.


Can Alzheimer's Disease be Reversed?

Learning you have Alzheimer's disease can be devastating. Working with your health care team can help you find the best strategies to manage your symptoms and prolong your independence.

Alzheimer's drugs might be one strategy to help you temporarily manage memory loss, thinking and reasoning problems, and day-to-day function. Unfortunately, Alzheimer's drugs don't work for everyone, and they can't cure the disease or stop its progression. Over time, their effects wear off.

Research into more-effective Alzheimer's drugs is ongoing. If you can't take the approved medications or they don't work for you, ask your doctor if you might be eligible for a clinical trial.


What is the average life expectancy for Alzheimer's Disease?

Life expectancy varies for each person with Alzheimer's Disease. The average life expectancy after diagnosis is eight to 10 years. In some cases, however, it can be as short as three years or as long as 20 years.

Alzheimer's Disease can go undiagnosed for several years, too. In fact, the average length of time between when symptoms begin and when an Alzheimer's Disease diagnosis is made is 2.8 years.


How much time can Alzheimer's Disease treatment add?

Treatment will not prevent the progression of Alzheimer's Disease. It is also unclear if treatment can add time to a person’s life. Ultimately, Alzheimer's Disease will progress and take its toll on the brain and body. As it progresses, symptoms and side effects will get worse.

However, a few medications may be able to slow the progression of Alzheimer's Disease at least for a short time. Treatment can also improve your quality of life and help treat symptoms. Talk with your GP about your treatment options.