Alzheimer’s disease is a progressive disease that destroys memory and other important mental functions.
It’s the most common cause of dementia — a group of brain disorders that results in the loss of intellectual and social skills. These changes are severe enough to interfere with day-to-day life.
In Alzheimer’s disease, the brain cells themselves degenerate and die, causing a steady decline in memory and mental function.
Current Alzheimer’s disease medications and management strategies may temporarily improve symptoms. This can sometimes help people with Alzheimer’s disease maximize function and maintain independence.
But because there’s no cure for Alzheimer’s disease, it’s important to seek supportive services and tap into your support network as early as possible.
At first, increasing forgetfulness or mild confusion may be the only symptoms of Alzheimer’s disease that you notice. But over time, the disease robs you of more of your memory, especially recent memories. The rate at which symptoms worsen varies from person to person.
If you have Alzheimer’s, you may be the first to notice that you’re having unusual difficulty remembering things and organizing your thoughts. Or you may not recognize that anything is wrong, even when changes are noticeable to your family members, close friends or co-workers.
Brain changes associated with Alzheimer’s disease lead to growing trouble with:
Everyone has occasional memory lapses. It’s normal to lose track of where you put your keys or forget the name of an acquaintance. But the memory loss associated with Alzheimer’s disease persists and worsens, affecting your ability to function at work and at home. People with Alzheimer’s may:
- Repeat statements and questions over and over, not realizing that they’ve asked the question before
- Forget conversations, appointments or events, and not remember them later
- Routinely misplace possessions, often putting them in illogical locations
- Eventually forget the names of family members and everyday objects
Disorientation and misinterpreting spatial relationships
People with Alzheimer’s disease may lose their sense of what day it is, the season, where they are or even their current life circumstances. Alzheimer’s may also disrupt your brain’s ability to interpret what you see, making it difficult to understand your surroundings. Eventually, these problems may lead to getting lost in familiar places.
Speaking and writing
Those with Alzheimer’s may have trouble finding the right words to identify objects, express thoughts or take part in conversations. Over time, the ability to read and write also declines.
Thinking and reasoning
Alzheimer’s disease causes difficulty concentrating and thinking, especially about abstract concepts like numbers. It may be challenging to manage finances, balance checkbooks, and keep track of bills and pay them on time. These difficulties may progress to inability to recognize and deal with numbers.
Making judgments and decisions
Responding effectively to everyday problems, such as food burning on the stove or unexpected driving situations, becomes increasingly challenging.
Planning and performing familiar tasks
Once-routine activities that require sequential steps, such as planning and cooking a meal or playing a favorite game, become a struggle as the disease progresses. Eventually, people with advanced Alzheimer’s may forget how to perform basic tasks such as dressing and bathing.
Changes in personality and behavior
Brain changes that occur in Alzheimer’s disease can affect the way you act and how you feel. People with Alzheimer’s may experience:
- Social withdrawal
- Mood swings
- Distrust in others
- Irritability and aggressiveness
- Changes in sleeping habits
- Loss of inhibitions
- Delusions, such as believing something has been stolen
Many important skills are not lost until very late in the disease. These include the ability to read, dance and sing, enjoy old music, engage in crafts and hobbies, tell stories, and reminisce.
This is because information, skills and habits learned early in life are among the last abilities to be lost as the disease progresses. Capitalizing on these abilities can allow you to continue to have successes and maintain a high quality of life even when you are into the moderate phase of the disease.
As more and more brain cells die, Alzheimer’s leads to significant brain shrinkage. When doctors examine Alzheimer’s brain tissue under the microscope, they see two types of abnormalities that are considered hallmarks of the disease:
- Plaques. These clumps of a protein called beta-amyloid may damage and destroy brain cells in several ways, including interfering with cell-to-cell communication. Although the ultimate cause of brain-cell death in Alzheimer’s isn’t known, the collection of beta-amyloid on the outside of brain cells is a prime suspect.
- Tangles. Brain cells depend on an internal support and transport system to carry nutrients and other essential materials throughout their long extensions. This system requires the normal structure and functioning of a protein called tau.
In Alzheimer’s, threads of tau protein twist into abnormal tangles inside brain cells, leading to failure of the transport system. This failure is also strongly implicated in the decline and death of brain cells.
Older age, family history and genetics, female sex, mild cognitive impairment, past head trauma, lifestyle and heart health, lifelong learning and social engagement, and others listed below
- Lack of exercise
- High blood pressure
- High blood cholesterol
- Elevated homocysteine levels
- Poorly controlled diabetes
- A diet lacking in fruits and vegetables
Tests and Diagnosis
Your doctor will perform a physical exam, and is likely to check your overall neurological health by testing your:
- Muscle tone and strength
- Ability to get up from a chair and walk across the room
- Sense of sight and hearing
Blood tests may help your doctor rule out other potential causes of memory loss and confusion, such as thyroid disorders or vitamin deficiencies.
Mental status testing
Your doctor may conduct a brief mental status test to assess your memory and other thinking skills. Short forms of mental status testing can be done in about 10 minutes.
Your doctor may recommend a more extensive assessment of your thinking and memory. Longer forms of neuropsychological testing, which can take several hours to complete, may provide additional details about your mental function compared with others’ of a similar age and education level.
This type of testing may be especially helpful if your doctor thinks you may have a very early stage of Alzheimer’s disease or another dementia. These tests may also help identify patterns of change associated with different types of dementia and can help doctors estimate your ability to safely manage important activities, such as financial and medical decision-making.
Images of the brain are now used chiefly to pinpoint visible abnormalities related to conditions other than Alzheimer’s disease — such as strokes, trauma or tumors — that may cause cognitive change. New imaging applications — currently used primarily in major medical centers or in clinical trials — may enable doctors to detect specific brain changes caused by Alzheimer’s.
Brain-imaging technologies include:
- Magnetic resonance imaging (MRI). An MRI uses radio waves and a strong magnetic field to produce detailed images of your brain. You lie on a narrow table that slides into a tube-shaped MRI machine, which makes loud banging noises while it produces images. MRIs are painless, but some people feel claustrophobic inside the machine and are disturbed by the noise.
MRIs are used to rule out other conditions that may account for or be adding to cognitive symptoms. In addition, they may be used to assess whether shrinkage in brain regions implicated in Alzheimer’s disease has occurred.
- Computerized tomography (CT). For a CT scan, you’ll lie on a narrow table that slides into a small chamber. X-rays pass through your body from various angles, and a computer uses this information to create cross-sectional images (slices) of your brain. It’s currently used chiefly to rule out tumors, strokes and head injuries.
- Positron emission tomography (PET). During a PET scan, you’ll be injected in a vein with a low-level radioactive tracer. You’ll lie on a table while an overhead scanner tracks the tracer’s flow through your brain.
The tracer may be a special form of glucose (sugar) that shows overall activity in various brain regions. This can show which parts of your brain aren’t functioning well. New PET techniques may be able to detect your brain level of plaques and tangles, the two hallmark abnormalities linked to Alzheimer’s.