Alzheimer’s disease is a progressive brain disorder that slowly destroys memory and thinking skills. It is the most common cause of dementia among older adults. There are two types of Alzheimer’s disease: late-onset and early onset. Late-onset typically develops in people in their mid-60s. Early-onset is very rare and occurs between the ages of 30 and mid-60s.
The terms dementia and Alzheimer’s are often used interchangeably. However, Alzheimer’s is a type of dementia. Dementia is a broad term for conditions with symptoms related to memory loss, forgetfulness, and confusion. Dementia also includes conditions such as Alzheimer’s, Parkinson’s disease, and Huntington’s disease.
It is estimated that as many as 5.5 million Americans age 65 and older have Alzheimer’s disease. Many more under the age of 65 will develop the disease. With current trends, the number of people with Alzheimer’s will increase significantly. This is because increasing age is the most important known risk factor for Alzheimer’s disease.
Dr. Alois Alzheimer discovered the disease in 1906. A woman died from an unusual mental illness with symptoms of memory loss, language problems, and unpredictable behavior. After her death, Dr. Alzheimer studied her brain and noticed changes in the brain tissue. He found many abnormal clumps (now called amyloid plaques) and tangled bundles of fibers (now called neurofibrillary).
These plaques and tangles in the brain are some of the main features of Alzheimer’s disease. Another trait is the loss of connections between nerve cells (neurons) in the brain. Neurons transmit messages between different parts of the brain, and from the brain to muscles and organs in the body. Many other complex brain changes are thought to play a role in Alzheimer’s too.
The damage initially appears to take place in the part of the brain called the hippocampus, which is essential in forming memories. As neurons die, additional parts of the brain are affected. By the final stage of Alzheimer’s, damage is widespread, and brain tissue has shrunk significantly.
Alzheimer’s disease is currently ranked the sixth leading cause of death in the United States. However, recent estimates indicate that it may rank third – behind heart disease and cancer. Although treatment can help manage symptoms for some, currently there is no cure.
What Does Alzheimer’s Disease Look Like?
The first signs of Alzheimer’s disease is memory problems, though initial symptoms may vary from person to person. Trouble finding the right words, vision/spatial issues, and impaired judgement may also be signs of very early stages of Alzheimer’s disease. Mild cognitive impairment (MCI) is a condition that can be an early sign of Alzheimer’s, but not everyone with MCI will develop the disease.
It can be difficult for someone with Alzheimer’s to do everyday activities like driving a car, cooking a meal, or paying bills. They may also ask the same questions over and over, get lost easily, lose things or put them in odd places. As the disease progresses, some become worried, angry, or violent.
Alzheimer’s will gradually worsen over time. It is broken down into seven different stages:
- Stage 1: There are no symptoms, but an early diagnosis may occur based on family history.
- Stage 2: The earliest symptoms appear, such as forgetfulness.
- Stage 3: Mild physical and mental impairments appear, such as reduced memory and concentration. These may only be noticeable by someone very close to the person.
- Stage 4: Alzheimer’s is often diagnosed at this stage, but it’s still considered mild. Memory loss and the inability to perform everyday tasks is noticeable.
- Stage 5: Moderate to severe symptoms require help from loved ones or caregivers.
- Stage 6: At this stage, a person with Alzheimer’s may need help with basic tasks, such as eating and putting on clothes.
- Stage 7: This is the most severe and final stage of Alzheimer’s. There may be a loss of speech and facial expressions.
People with Alzheimer’s disease display certain ongoing behaviors and symptoms that worsen over time. Symptoms change or worsen depending on the stage of the disease. Symptoms include:
- Memory loss affecting daily activities
- Trouble with familiar tasks
- Difficulties with problem-solving
- Trouble with speech or writing
- Becoming disoriented about times or places
- Decreased judgement
- Decreased personal hygiene
- Mood and personality changes
- Withdrawal from friends, family, and community
Age – The greatest known risk factor is aging. Most people who develop Alzheimer’s disease are 65 years of age or older. After age 65, the risk of developing Alzheimer’s doubles every 5 years. After age 85, the risk reaches nearly one-third.
Family history – Those who have a parent, brother, or sister with Alzheimer’s are more likely to develop the disease. The risk increases if more than one family member has the illness.
Genetics – Certain genes have been linked to Alzheimer’s disease. Two categories of genes influence whether a person develops a disease, risk genes and deterministic genes. Alzheimer’s genes are found in both of these categories.
People with Down syndrome are more likely to develop early-onset Alzheimer’s. Autopsy studies show the by age 40, the brains of almost all individuals with Down syndrome have significant levels of plaques and tangles, and abnormal protein deposits. Over 50% of people with Down syndrome will develop Alzheimer’s as they age.
Heart-head connection – Some of the strongest evidence links heart health with brain health. The risk of developing Alzheimer’s or vascular dementia appears to increase is a person has conditions that damage the heart and blood vessels. This includes heart disease, diabetes, stroke, high blood pressure, and high cholesterol.
There is no foolproof preventive measure; however, researchers are focusing on overall healthy lifestyle habits as ways to prevent cognitive decline.
- Quit smoking
- Exercise regularly
- Try cognitive training exercises
- Eat a plant-based diet
- Consume more antioxidants
- Maintain an active social life
- Reduce stress – Excessive stress can result in reduced memory capacity.
There is no definitive test for Alzheimer’s disease. However, your doctor will likely preform several tests to determine your diagnosis. These can be mental, physical, neurological, and imaging test.
A health care professional may start with a mental status test that will access your short-term memory, long-term memory, and orientation to time and place. Next they will likely conduct a physical exam, such as checking your blood pressure, assessing your heart rate, and taking your temperature.
Your doctor may then conduct a neurological exam to rule out other possible diagnoses. They may then order brain-imaging studies. These test will create images of your brains and can include:
- Magnetic Resonance Imaging (MRI) – These help pick up key markers, such as inflammation, bleeding, and structural issues.
- Computed Tomography (CT) scan – These take x-ray images that help detect abnormal characteristics in your brain.
- Positron Emission Tomography (PET) scan – These images help your doctor detect plaque buildup.
Engaging in mental exercise seems to help develop additional neurons and pathways to the brain. An active brain may help reduce your risk of Alzheimer’s. This includes:
- Listening to the radio
- Reading the newspaper
- Playing puzzle games – crosswords, sudoku, word search
- Visiting Museums
- Learn a new language
- Taking a course
- Learn/play a musical instrument
- Paint or other artistic hobbies
- Participate in leisure activities – sports, dancing, gardening
- Board games
Sources: HealthLine.com and Alzheimer’s Association
Links to various resources on the topics discuss on this page.