What is Alzheimer’s disease?
Alzheimer's disease is an irreversible and progressive brain disorder, wherein the connections between the nerve cells or neurons are lost and ultimately die. It is also one of the most common causes of dementia that causes loss of intellectual and social skills. As the disease progresses, it causes the brain cells to degenerate and die, which in the process, leads to a steady decline in memory and mental functioning.
To start with, an individual may experience mild confusion and memory problems. As the disease progresses, people with Alzheimer's tend to forget their family and loved ones. The rate of brain deterioration varies from person-to-person. It is recently believed that Alzheimer's disease does begin to create changes in the brains of the affected people much before its onset. The reason is that specific areas of the brain begin to be affected about 10-20 years before the onset of the visible symptoms.
The Stages of Alzheimer's Disease
Several stages in the progression of the disease have been identified. In the very early stages, people with Alzheimer's do not show any obvious symptoms and the disease can only be detected using the PET brain scan.
In the next stage, the affected patient could be forgetting words and misplacing objects. However, these mild symptoms do not interfere with their day-to-day and independent living. Often, people with Alzheimer’s may experience depression, apathy, and mood swings. As the disease progresses to the next stage, noticeable changes can be seen in the person's thinking and reasoning capabilities, thereby hampering their decision-making abilities. In this stage, the person keeps on repeating the same questions over and over again, forgets things that are recently read, cannot remember new names and people, and have a hard time planning and organizing.
There is a further moderate decline in the stage that follows. They have a difficulty in organizing their thoughts and thinking logically. Problems seen in the previous stage of the disease are more obvious here, along with more issues such as forgetting details about oneself, forgetting months and seasons, and having issues in dealing with daily chores. The affected person also loses track of time, forgets his address, phone number, other personal details, and also gets confused regarding the kind of clothes he or she has to wear according to the season. They also have hallucinations, delusions, become increasingly more suspicious or paranoid, and irritable.
Following this stage is where further deterioration sets in. One may forget people's names but may remember their faces. In this stage, they also need help to go to the bathroom. Other problems in this stage are reading, writing, and working with numbers. As the disease progresses, it takes more control over the brain making changes in the person's thinking and reasoning processes.
Therefore, in the final stages, there is severe deterioration wherein the person can no longer recognize his or her own family and loved ones. They also lose their communication skills and become completely dependent on others for everything. Many times at this stage, they cannot even tell if they are thirsty. Other symptoms also include weight loss, seizures, skin infections, difficulty in swallowing, groaning, moaning, grunting, increased sleeping, and lack of bladder and bowel control. They are also in bed most of the time until their death due to other complications that arise.
In many cases, the changes in the brain begin to affect a person's physical functions such as swallowing, balance, as well as bowel and bladder control. These impaired physical functions could increase one's vulnerability to other additional problems such as aspiration pneumonia due to the inhalation of food or liquid into the lungs, falls, fractures, bedsores, malnutrition, and dehydration.
Types of Alzheimer’s
Alzheimer's disease has been categorized into two types: early-onset and late-onset. The early-onset type affects the 30-60 years age group, while the late onset develops in people after 60 years old.
- Early-onset - This type is very rare and represents only 5 percent of Alzheimer's cases. The causes for the early-onset type of Alzheimer's have mostly been attributed to hereditary factors. Familial Alzheimer's disease is responsible for the early-onset type of Alzheimer's, wherein there are several different single gene mutations that are responsible for the disease.
- Late-onset - This disease creeps in at a later stage in life usually after 60 years of age and is the most common type of Alzheimer's disease. The factors that are responsible for causing it are not yet very well understood. A combination of several factors such as genetic, environmental, and lifestyle seem to play a key role in increasing one’s susceptibility to developing the disease. Although statistics indicate that 60-80 percent of the late-onset type of Alzheimer’s cases are due to genetic factors, environmental factors also have an equal role and contribution in the onset progression and the severity of the disease.
Main Causes Associated with Alzheimer's
The brain of a person with Alzheimer's disease shrinks with the progression of the disease as more and more brain cells die with time. Two types of abnormalities are observed in the brains of people with Alzheimer's disease. Amyloid plaques and neurofibrillary tangles are the two types of abnormalities that develop in the Alzheimer's brain.
The brain cells are destroyed and damaged by the formation of amyloid plaques that are basically clumps of beta-amyloid protein, which could also interfere with the normal communication channels between the cells. Tangles are formed when threads of tau protein, which is required for the normal functioning of the transport system within the brain, twists into abnormal tangles inside the brain cells, thereby derailing the transport system.
There is a growing risk of Alzheimer's as people age. Although Alzheimer's is not a normal part of aging, after the age of 65, the risk of developing the disease increases. It is said that after the age of 60, the rate of dementia doubles every decade.
As already stated in the beginning, the early-onset Alzheimer's, which starts to develop after 30 years of age, is very rare. Hereditary factors have been identified as the root causes for this kind of Alzheimer's. On the whole, genetic factors play a major role in developing Alzheimer's. People who are genetically predisposed and those who have either a parent or a sibling with the disease seem to be at a higher risk of developing Alzheimer's.
Many people with Down syndrome seem to develop Alzheimer's disease, and the signs and symptoms appear much earlier in cases with Down syndrome in comparison to others. The extra chromosome that causes Down syndrome seems to have a gene that make these people more vulnerable to Alzheimer's. People with vascular dementia are also at a higher risk.
Women are also more susceptible to the disease than men, as they tend to live longer. Many people with mild cognitive impairment (MCI) are also more susceptible to developing Alzheimer's. People with traumas in the head are also at a greater risk of developing the disease.
Managing Alzheimer’s Disease
The prescribed medications for Alzheimer's patients only treat the symptoms and do not cure the disease. Antidepressants, anxiolytics, antiparkinsonian agents, beta blockers, antiepileptics, and neuroleptics have been used to treat the secondary symptoms of Alzheimer's such as depression, agitation, aggression, hallucinations, delusions, and sleep disorders.
Can Alzheimer's be prevented?
One should opt for a healthy lifestyle and design strategies to combat or delay the onset of Alzheimer's. Although living a healthy lifestyle does not necessarily guarantee the prevention of Alzheimer's, studies show that the disease may be further delayed. The following practices may help prevent or delay the onset of Alzheimer's disease:
- Having regular exercises
- Cardiorespiratory fitness
- Proper control of blood pressure and cholesterol levels
- Quitting smoking
- A good intake of fiber-rich fruits and vegetables
The Mediterranean diet has been found to be beneficial for the prevention of Alzheimer's disease. Engaging in lifelong learning as well as being socially involved and active have also shown to help in the prevention of the disease.