What is Alzheimer’s disease?
In 1986, President Ronald Reagan of the United States often responded to his opponents with lame answers such as "I can't remember" and "I don't remember" when certain political parties were fighting. . However, his response was likely to be genuine rather than political. Because, in 1994, outgoing President Ronald Reagan announced that he was suffering from Alzheimer's disease.
Ronald Reagan
Alzheimer's disease attacks the human brain; it is not a normal part of aging. People with Alzheimer's disease gradually lose their memory and develop language and emotional difficulties. The gradual loss of intelligence is called dementia. As the disease becomes more severe, patients will need help from others in all aspects of life, such as bathing, eating, going to the toilet, etc. Because Alzheimer’s patients require day and night care, the lives of their relatives and friends are often greatly affected. Alzheimer's disease is still an irreversible and untreatable disease.
Who gets Alzheimer’s disease?
Approximately 5-6% of the population in the United States suffers from Alzheimer's disease or related dementia symptoms. This means that nearly 4 million Americans are living with Alzheimer's disease. As patients age and degenerate, the burden on caregivers and society becomes increasingly heavy. It is estimated that by 2050, 14 million people in the United States will be suffering from Alzheimer's disease. Alzheimer's disease ranks as the fourth leading cause of death among adults in the United States. 100,000 people die from Alzheimer's disease every year. 5-10% of people over the age of 65 are affected by Alzheimer's disease. Half of the population over the age of 85 has Alzheimer's disease. Age is one of the factors related to Alzheimer's disease, and research shows that "heredity" also plays an important role. Because women generally live longer than men, more women than men suffer from Alzheimer's disease. Additionally, 80% of Alzheimer’s caregivers are women, so they are also indirectly affected by Alzheimer’s disease.
Estimated number of Alzheimer’s patients in the United States (millions)
Symptoms
Memory loss may be the most obvious symptom of Alzheimer’s disease symptoms, especially the inability to remember things that happened not long ago or information that was recently obtained. The initial symptoms are subtle and gradual and difficult to detect, and these symptoms may also occur in other dementias and are not specific to Alzheimer's disease. For example: getting lost in a familiar place, forgetting whether you have done something, always mentioning old things again, or being unable to learn new things. As the condition worsens, patients may have difficulty finding the right words to use in conversations or make important decisions.
One of the most distressing aspects of Alzheimer's disease is that patients sometimes have trouble recognizing family and friends. The patient's personality may also become extremely irritable, paranoid and suspicious, and he or she does not like to interact with others. In the later stages, patients may wander on the streets and become lost and unable to return home. New research suggests that people with Alzheimer's disease may have damage to areas of the brain that process visual and spatial information. This may explain why patients have problems recognizing where they are or being disoriented. Sufferers may also become distracted and therefore unable to care for their own daily physical needs. Other areas of the brain important for memory are also affected in Alzheimer's patients, such as the basal forebrain and hippocampus. Many people suffering from Alzheimer's disease die from other causes, such as pneumonia. Counting from the date of diagnosis, patients with Alzheimer's disease generally have a life expectancy of 6-8 years, but many patients still survive for more than 20 years.
Symptoms of Alzheimer's disease vary widely among individuals, but eventually symptoms worsen for everyone. Many behavioral changes accompany Alzheimer's disease—depression, paranoia, and delusions. However, there is currently no cure for Alzheimer's disease, although certain treatments appear to have some effect.
Brain areas affected by Alzheimer's disease
A = Cerebral cortex
B = Basal forebrain
C = Hippocampus Back
Image source: NIA
Illustration: Lydia Kibiuk
A closer look at the brains of Alzheimer’s patients
In 1906, German neuroscientist Alois Alzheimer was the first to record microscopic changes in the brains of Alzheimer's patients. (In 1906, the German neuroscientist Eros Alzheimer recorded the brain changes of Alzheimer's patients for the first time with microscopic images.) He presented the pathological anatomy of a woman whose mind was in her The first few years of the afterlife were increasingly chaotic. He called the changes he observed in the woman's brain plaques and tangles. These features can only be observed through pathological anatomy. Tangles and plaques block the ability of nerves to communicate with each other and carry messages.
Some studies speculate that these struggles are part of the normal aging process. Dr. John Morris of the University of Washington School of Medicine published an article in the Annals of Neurology (Volume 45 Number 3, pages 358-368) in March 1999 titled "The Phenomenon of Psychotic Aging and its Preclinical The tangles and plaques seen in Alzheimer’s disease.” The study showed that tangles were also found in the brains of 39 non-psychotic people, who showed no behavioral symptoms of Alzheimer's disease. Therefore, the gradual accumulation of tangles in the brain may be an inevitable part of the aging process. "This is further evidence that entanglement is a normal occurrence of aging and does not necessarily lead to Alzheimer's disease," Murrys said in his paper. More research is needed to help us figure out the role tangles and plaques play in Alzheimer's disease. Are plaques alone the cause of Alzheimer's disease, or do plaques and plaques interact with each other?
Other changes that can be observed in the brains of people with Alzheimer's disease:
Neurodegeneration in part of the brain's nucleus basalis of Meynert Phenomenon
Reduction in the neurotransmitter acetylcholine in the brain
Image source: NIA
Illustration: Lydia Kibiuk
Neurofibrillary Tangles
It is not clear how neurofibrillary tangles (NFTs) are formed. Nerve fiber tangles are found inside nerves: these tangled nerves have cells that are severely deformed and stacked into clumps. It has also been described as being like a rope with many knots. Some researchers have pointed out that a protein called "Tau" is related to the formation of neurofibrillary tangles (NFTs). But how do neurofibrillary tangles form? Why should it be formed? And how do these tangles affect the brain?
Plaques
Unlike tangles, plaques accumulate on the outside of nerve cells. Plaques are mainly composed of a protein called beta amyloid, but other proteins are also involved in plaque formation. Research shows that a protein in our body called amyloid plays an important role in Alzheimer's disease. Proteins are molecules needed to sustain life and control various reactions in the body. Amyloid protein is naturally produced in our brains, but as we age there is an excess of amyloid, and it accumulates in the brain in the form of beta amyloid. Plaques form.
The new fragment produced after the amyloid precursor protein is cleaved by enzymes is called beta amyloid; this protein easily aggregates to form a precipitate. It remains to be determined whether these precipitates are caused by overproduction of beta amyloid, or by the inability of the enzymes responsible for breaking down the protein to function properly. This situation is similar to the situation of cholesterol (cholesterol) in our body. Some cholesterol is needed to maintain the health of our cells, but too much cholesterol can clog blood vessels, lead to heart damage and other problems.
Image source: NIA
Illustration: Lydia Kibiuk
Drug treatment
There are only two treatments for Alzheimer's disease, Cognex and Aricept of drugs are approved by the US Food and Drug Administration (FDA). These drugs are cholinesterase inhibitors (non-brand names are tacrine and donepezil respectively). Cholinesterase is a key enzyme in the breakdown reaction of acetylcholine. These drugs work by blocking the enzyme cholinesterase (tacrine and donepezil). cholinesterase) to inhibit the breakdown of acetylcholine. Both drugs increase levels of acetylcholine in the brain. Both drugs slow memory loss and help patients perform the actions they need to perform daily activities. It’s important to note that these drugs do not cure Alzheimer’s disease; they only reduce the symptoms of Alzheimer’s disease.
Since Tacrine has side effects on certain enzymes in the liver, the new drug rivastigmine developed for this purpose may soon be approved by the FDA. This drug acts specifically on the brain and does not affect enzymes in the liver. There are at least 17 other drugs to treat Alzheimer's disease waiting for approval by the US FDA.
Other treatments
Vitamin E (an antioxidant) and aspirin (an anti-inflammatory drug) are thought to be effective in Alzheimer's disease. But how either slows Alzheimer's symptoms is unclear. Some researchers have speculated that vitamin E can protect the cell membranes of nerve cells from damaging oxidation.
Research shows that certain artificial devices (architectural designs) can be used to assist Alzheimer's patients. For example, posting notices in a building showing the building's floor plan could help a lost Alzheimer's patient find the location of their room. Using small signs or graphics to remind patients of certain things to do can help patients focus. Following the same routine every day can also help patients remember what they should do now.
Some studies show that a plant called Gingko Biloba may have some effect on symptoms of Alzheimer's disease.
Dr. Harry S. Goldsmith of Nevada State University School of Medicine has proposed a controversial surgical treatment for AD (controversial surgical treatment for AD). He moved the intra-abdominal omentum, a tissue that supports organs in the abdomen, into the brain. Perhaps because of omentum's chemical properties, this treatment may improve short-term memory in Alzheimer's patients, but further research is needed to explain why the procedure works.
Expanding Diagnostic Tools
Since the most reliable diagnosis of Alzheimer's disease cannot be established until the patient's brain is examined after death, it must be ruled out while the patient is still alive. method to diagnose whether a patient has Alzheimer's disease. This means ruling out other possible causes of dementia first. There is no way to tell whether a person has Alzheimer's disease based on just one test, but certain tests can help predict whether a person is suffering from Alzheimer's disease.
When analyzing cerebrospinal fluid, if there is an increase in the levels of certain proteins, such as amyloid beta protein, it means that the patient may be suffering from Alzheimer's disease.
As imaging technology becomes more sophisticated and accessible, medical professionals can use Computerized Axial Tomography (CAT scans) to observe the degree of brain contraction. When the dimples (sulci) on the surface of the brain become wider and the ventricles (the spaces in the brain filled with cerebrospinal fluid) become larger, these are hallmarks of Alzheimer's (as well as other neurological diseases).
Brain imaging technology can also be used to obtain the status of blood flow and metabolic activity in different brain regions.
PET Scans
Risk factors
The first and most important one is that the probability of Alzheimer’s disease will increase with aging. And increase. As people age, they are more likely to develop symptoms of Alzheimer's disease. Men and women are equally likely to develop Alzheimer's disease, and it affects all races.
There are actually two main types of Alzheimer's disease: familial (early-onset) and sporadic (late-onset). Familial Alzheimer's is rare, and very few people will develop it by the time they are five years old. Onset before the age of ten. This type of Alzheimer's disease has a strong genetic component: mutations in some genes located on chromosomes 21, 14, and 1 predispose to Alzheimer's disease. (Reported in Neurology, July 1998.)
Most patients with Alzheimer's disease have sporadic forms of Alzheimer's disease. Most of them develop the disease between the ages of 65 and 75. A gene called APOE on chromosome 19 has been pinpointed as being a risk factor for AD (JAMA, August 19, 1998, Vol. 280, #7.), as it has a gene called APOE on chromosome 12.
What can we do to protect our brains as we age?
As we age, certain connections in the brain will fail due to tangles or plaque formation. The extended concept is that the more neural connections we have, the more connections we can withstand. There are more defects. Just like a team! If a player on the field is injured and there is a capable substitute player to fill in, the entire team can still operate very well. The more players that can be replaced, the smoother the team can operate.
How to form and maintain neural connections? As the saying goes: If you want to move, move! Keeping your mind and body flexible helps! Challenge your mind: try to remember other people's names, do crossword puzzles, do math problems, read, learn new words.
Directions for Future Research
Understanding Alzheimer's disease is one of the most active research topics in neuroscience. In 1998, scientists took a big step forward by breeding mice capable of developing Alzheimer's disease. These mice are helping researchers unlock the mysteries of Alzheimer's disease.
Research on future treatment methods can be divided into several types:
Treatment methods based on chemical theories (Chemical Theories)
Biochemical changes in the brain
Cells in the brain require certain nutrients to grow. One of these nutrients is called nerve growth factor (NGF). Reduced nerve growth factor (NGF) contributes to Alzheimer's disease. Experiments in rats show that nerve growth factor promotes the formation of new synaptic connections in the hippocampus of the brain. In this theory, the formation of new connections can reverse memory loss. While there are chemicals that can help nerve growth, there are also chemicals that are poisonous and kill nerves. These chemicals are called neurotoxicants. It may be that increased levels of neurotoxins contribute to the disease. If the levels of these neurotoxic substances could be regulated, less nerve cells would die, thereby alleviating the symptoms of Alzheimer's disease.
Defects in neurotransmitters in the brain
Nerve cells use neurotransmitters to communicate. As mentioned before, people with Alzheimer's disease have lower levels of acetylcholine in their brains than people without the disease. Medications that reduce acetylcholine can cause temporary memory loss as a side effect. Therefore, drugs that promote increased levels of acetylcholine in the brain may slow the onset of dementia.
Toxic Chemical Excess in the Brain
In the past, aluminum, mercury, and other metals have been found in the brain tissue of Alzheimer's patients, so it is speculated that these Molecules contribute to the disease. Most scientists agree that aluminum and other metals do not cause Alzheimer's disease. Further research is needed to clarify the role these metals play in Alzheimer's disease.
The Genetic Theory
The genetics of Alzheimer's disease are the most confusing. Some families may have many members affected. However, because family members may be exposed to the same environment, it is impossible to say how much genetic factors are responsible. AD. Several genes located on chromosomes 21 and 14 have been identified, and they are familial. Unique to Alzheimer's disease. For the most common sporadic form of Alzheimer's disease, people who carry apolipoprotein E (APOE) on chromosome 19 have Alzheimer's disease. The incidence is higher than in the general population. More research needs to be done to understand how genetic factors influence the development of Alzheimer's disease.
The Autoimmune Theory
Your immune system defends your health and protects you from infection by bacteria, viruses, and other threats. If this system is functioning When it goes haywire, your immune system attacks your own tissue. Scientists hypothesize that if your immune system attacks your brain as you age, it can cause Alzheimer's disease. However, it's not yet clear whether autoimmunity causes Alzheimer's. Alzheimer's disease, because signs of autoimmunity can be seen in the brains of people who don't have Alzheimer's disease.
The Slow Virus Theory
Brain diseases caused by certain chronic viruses have symptoms similar to Alzheimer's disease. However, there is no specific The virus has been confirmed to cause Alzheimer's disease.
Literature and further information
1. I Lost Myself—The Story of Alzheimer’s Disease Conrad. Konrad Maurer, Wulik. Ulrike Maurer; Translated by Yang Mengru; Zhengzhong Bookstore
2. Alzheimer's Clinic (There's Still A Person in There) Matthew Nassons et al.; Yi Zhixin/ Translated; Tianxia Culture
3. DIN Disability Service Information Network
4. Oh...my dear, why are you willing to go away like this... In this world, lovers may not be as loyal as pets. Years… What you need to know: Alzheimer’s disease in pets—Cognitive dysfunction
5. Alzheimer’s disease: some clues to the mystery of memory
6. Alzheimer’s disease Alzheimer's Disease - Guidelines for Aging Education
7. Alzheimer's Disease - American Health Assistance Foundation
8. Alzheimer's Disease - Unsolved Mysteries
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9. An overview of Alzheimer’s disease
10. Alzheimer’s disease – US federal government aging research report
11. Alzheimer’s disease – National Center for Neurological Disorders and Stroke
12. Alzheimer’s Disease Education and Referral Center
13. Alzheimer’s Association website
14. National Center on Aging Public Service Announcement
15. Reference Books for Children and Adolescents with Alzheimer’s Disease