What is Alzheimer’s Disease?

Alzheimer’s disease (AD) is an irreversible, progressive neurological disorder characterized by a gradual loss of cognitive functioning, eventually leading to the inability to accomplish the simplest regular tasks and respond to the environment. Late-onset symptoms in most people with Alzheimer’s first appear in the mid-60s.

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Alzheimer’s disease is the most common cause of dementia among older people, accounting for approximately 60-80% of dementia cases. Dementia is a general term used to describe the impairment of cognitive abilities – thinking, reasoning, also remembering – to an extent that significantly impacts a person’s everyday activities.

The disease starts in the brain region responsible for recent memory and then gradually spreads to the other parts. Alzheimer’s destroys the connection between brain cells (neurons), eventually causing cell death and shrinkage, damaging the brain regions responsible for memory, language, intelligence, judgment, and the formation of new memories.

Alzheimer’s disease is named after a German doctor, Alois Alzheimer, who first identified it in 1906. His pioneering work is based on a case of a 51-year-old woman who exhibited an unusual mental illness with symptoms, including memory loss, profound confusion, disorientation, and suspicion, up until her death. At autopsy, Dr. Alzheimer found startling cerebral atrophy (brain shrinkage) along with abnormal clumps and tangled bundles of fibers in her brain.

Today, we know these clumps and tangled fiber bundles as beta-amyloid plaques and neurofibrillary tangles, respectively, which are hallmarks of Alzheimer’s disease. The progressive loss of connection between neurons leading to cell death is another key feature of this disease.

Alzheimer’s Is Not A Normal Part Of Aging!

Mild forgetfulness and changes in both thinking and memory are usually associated with aging. The brain conventionally shrinks to a certain extent in healthy aging, but the loss of neurons is in lesser numbers. Whereas in Alzheimer’s disease, there is extensive brain damage as a substantial number of neurons lose connections, stop functioning, and die.

Alzheimer’s Is A Progressive Disorder.

Alzheimer’s is a progressive disease that develops gradually and worsens over time. Its progression varies widely among people as different individuals experience symptoms differently. The disease progression is usually divided into a series of stages in order to get an idea of how it progresses and what changes in a person occur over time.

It is still unclear how the Alzheimer’s process starts. However, it is a known fact that it may initiate 10 to 20 years before showing any noticeable signs of significant memory loss and forgetfulness. Typically, the Preclinical Stage of the disease.

In the early stages of the disease, the Alzheimer’s patient shows signs of mild cognitive impairment and mild to moderate dementia, characterized by noticeable memory loss and difficulty in completing daily tasks. With the progression of the disease, the affected brain portion continues shrinking with increased cell death. In the late stage, the physical abilities of the Alzheimer’s patients also begin to diminish along with the worsening cognitive impairment, and they require assistance to carry out the regular and self-care tasks. At this stage, the cell damage is widespread with significant brain shrinkage.

Alzheimer’s Risk Factors

Alzheimer’s is a complex disease. Researchers are convinced it is not caused by just a single factor. Instead, multiple factors, including genetics, lifestyle, and environment, are likely to be responsible for its development.
Scientists have disclosed certain risk factors of Alzheimer’s disease. While some factors, such as age, genetics, and family history, cannot be altered, growing research suggests there are certain other factors that we can influence.

Increasing age is one of the significant risk factors of the disease, primarily for patients aged 65 and older. Alzheimer’s and dementia, however, are not the natural parts of healthy aging. Although age increases the risk, it does not necessarily cause Alzheimer’s disease. Alzheimer’s risk doubles every five years after age 65, while it reaches about one-third after age 85.

Family history is another distinct risk factor for Alzheimer’s. People having a family history of Alzheimer’s have an increased likelihood of developing the disease. The risk further increases if more than one family member has had the disease.
When Alzheimer’s tends to run in the family, genetics automatically plays a role in increasing the disease risk in the individuals of that family. There is evidence of the involvement of genes in Alzheimer’s development. Scientists have discovered two types of genes that can increase a person’s risk of developing the disease: risk genes and deterministic genes. Deterministic genes cause the disease rather than increase the risk. The frequency of deterministic genes to cause Alzheimer’s is approximately less than 1%.

Certain lifestyle factors can be modified or influenced to slow the disease progression. Such factors include diet, physical and mental activity, socialization, and heart and vascular health.

How is Alzheimer’s Disease Treated?

Despite a lot of research conducted on Alzheimer’s disease, scientists are still unable to find a single cure for this devastating disease. Currently, there only exists a single FDA-approved treatment which is aducanumab (Aduhelm™). It is the first therapy that focuses on removing beta-amyloid from the brain to reduce cognitive and functional impairment in people with early-stage Alzheimer’s.
Other treatments include FDA-approved drugs that can briefly slow the disease progression to improve the quality of life for people with Alzheimer’s and their caregivers. Research is still underway globally to find better treatments and alternatives to prevent its development.

What is the Life Expectancy of People with Alzheimer’s?

The rate of Alzheimer’s progression widely differs from individual to individual. While the average life expectancy of people with the disease is between three to eleven years after diagnosis, some people can live as long as 20 years. How long a person will live with Alzheimer’s depends on the degree of impairment at diagnosis.