Alzheimer’s disease is a type of progressive neurocognitive impairment and is the most common degenerative brain disorder.
Dementia symptom of Alzheimer’s disease and includes a general decline or loss of the ability to think, remember, and reason.
At least 50 percent of all older adults with dementia have Alzheimer’s disease. More than 50 million people worldwide live with Alzheimer’s disease and other related causes of neurocognitive decline.
Alzheimer’s is a progressive disease in which abnormal proteins build amyloid plaques and tau tangles in the brain, damaging neurons (nerve cells) in certain parts of the brain and causing them to deteriorate and die.
Because of what happens to these neurons, people with Alzheimer’s can interpret their environment differently and act unpredictably.
They experience a type of mental deterioration that includes the loss of memories and the inability to think clearly.
Although people younger than 65 years of age can develop Alzheimer’s, it is primarily associated with advanced age.
A younger than 65 and is diagnosed with Alzheimer’s has early-onset or younger-onset Alzheimer’s.
This form of Alzheimer’s can occur as early as 30 years of age. It is usually caused by inheriting one of three defective or mutated genes.
At least 5 million people in the United States have the disease. However, an exact number is unknown because Alzheimer’s is often diagnosed incorrectly or not diagnosed until it has reached a late stage.
Up to half of the people who have Alzheimer’s have not yet been diagnosed with the disease. In the United States, more women have Alzheimer’s than men.
However, this seems to be related to the fact that women live longer than men. It also seems to be more common among African Americans.
Because of an aging population, the number of people diagnosed with Alzheimer’s will increase more than three times by 2050 to at least 16 million.
CAUSES AND SYMPTOMS
The exact causes of Alzheimer’s are unknown. It is generally accepted that Alzheimer’s is caused by a combination of genetic, environmental, and lifestyle factors.
Fewer than 5% of people with the disease inherit it.
The symptoms of Alzheimer’s can be grouped into three general types. They are related to brain function, behavioral and psychiatric issues, and daily life activities.
Symptoms related to brain function include:
- poor memory
- loss of language (such as not remembering the name of objects and/or repeating the same word or phrase over and over again)
- deprivation of the ability to do voluntary movements such as brushing teeth
- loss of the ability to recognize people who should be known
Symptoms related to behavior and psychiatric issues include:
- emotional overreactions to events
Symptoms related to daily activities include trouble with:
- personal care (such as bathing, grooming, using the toilet, and personal hygiene)
Medical professionals diagnose Alzheimer’s by observation and tests related to the brain, including those that show changes in the structure and size of the brain.
Physicians rule out other causes for dementia symptoms and changes in the brain through blood, urine, and imaging tests and evaluations related to issues such as depression and delirium.
Identifying Alzheimer’s disease earlier, while symptoms are mild, has been a goal of the Alzheimer’s Association.
Doctors combine information from the patient’s history, physical examination, and answers in a brief cognitive assessment.
The assessment takes five minutes or less and involves a series of questions, and might ask the patient to draw a clock face.
The activities are designed to spot dementia while it is early. Some older patients might be assessed if they show signs of cognitive impairment.
All patients on Medicare (age 65 and older) receive a mini-assessment as part of their annual exam.
Though doctors can accurately diagnose suspected Alzheimer’s in the living, the disease cannot be confirmed until after death.
A brain autopsy and an examination of brain tissue by a specialized pathologist is the only way of confirming that someone had the disease.
Some risk factors seem to play a role in determining if you get the disease. For example, the biggest risk factor for Alzheimer’s is aging.
The risk of getting Alzheimer’s increases after the age of 65 and greatly increases after 75.
In recent decades, research has emphasized the effect of lifestyle on Alzheimer’s disease risk.
According to physicians, the following five lifestyle factors can reduce the risk or delay start of dementia:
- never smoking or quitting smoking
- regular exercise (150 minutes per week of moderate to vigorous intensity)
- light or moderate use of alcohol (one drink a day for women and no more than two a day for men)
- eating high-quality foods such as green leafy vegetables, whole grains, seafood such as in the Mediterranean diet
- late-left brain activities, such as reading, writing letters, and playing games that require cognition
Other risk factors for Alzheimer’s include a family history of Alzheimer’s or Parkinson’s disease.
Brain damage from head trauma like a concussion or small strokes can also be a risk factor. The chance of developing the disease increases when people have low educational and occupational achievement.
High blood pressure combined with high cholesterol, obesity, and a mild cognitive impairment put some people at greater risk of getting the disease.
The mutation of certain genes leads to a greater chance of developing Alzheimer’s in certain people.
Though everyone with Alzheimer’s experiences the disease differently, the disease generally takes the same course and goes through seven stages.
People who have early-onset Alzheimer’s go through these stages more rapidly than late-onset Alzheimer’s.
The disease usually starts slowly, and the middle stages of Alzheimer’s begin about two or three years after the disease begins.
Alzheimer’s usually runs its course in eight to ten years, though in some cases, it can take 20 to 25 years to get through all the stages.
The stages are:
- No real change in function or other symptoms.
- Functioning mostly normally but with a subtle decline in intellectual function.
- Struggling to complete complex tasks that involve mental and intellectual function as the disease becomes more present.
- Moving from early Alzheimer’s to a mild form of the disease and needing help with tasks like paying bills.
- Experiencing moderate Alzheimer’s and requiring help in making basic life decisions daily, such as what clothing to put on, is appropriate for the weather.
- Experiencing moderately severe Alzheimer’s and needing help in basic functions like bathing and using the toilet.
- Experiencing severe Alzheimer’s, which includes the nearly complete loss of vocabulary and the ability to walk. The person becomes reliant on others for care.
As Alzheimer’s reaches its end, the disease affects the brain stem. A person dissipates the ability to digest food, breathe, and expel waste and spends most of the time sleeping.
Death from this disease is usually from infection, pneumonia, or lack of nutrition.
Sometimes, the person stops breathing.
No known cure exists for this disease. None of the effects of Alzheimer’s can be reversed, so once the symptoms are present, there is no recovery chance.
Treatments for Alzheimer’s focus on slowing the progression of the disease and helping the person with the disease to function independently for as long as possible.
An early diagnosis can aid in this process. Treatments for Alzheimer’s include establishing daily routines, good nursing care, sleeping, and physical and emotional support.
Certain drugs, such as cholinesterase inhibitors (Aricept, Razadyne, and Exelon), can improve brain function.
Memantine (Namenda) and a combination drug called Namzaric can help people with moderate to severe Alzheimer’s disease.
Music, light, and cognitive therapies are also helpful, as is sensory stimulation.
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“Alzheimer’s disease.” Mayo Clinic. December 8, 2018. https://www.mayoclinic.org/diseases-conditions/alzheimers-disease/symptoms-causes/syc-20350447 (accessed November 6, 2020).
“Alzheimer’s Disease Fact Sheet.” National Institute on Aging. May 22, 2019. https://www.nia.nih.gov/health/alzheimers-disease-fact-sheet (accessed November 6, 2020).
Hara, Yuko. “Five lifestyle factors associated with reduced Alzheimer’s risk.” Cognitive Vitality, Alzheimer’s Drug Discovery Foundation. June 19, 2020. https://www.alzdiscovery.org/cognitive-vitality/blog/five-healthy-lifestyle-factors-associated-with-reduced-alzheimers-risk (accessed November 6, 2020).