Alzheimer’s disease is a progressive neurocognitive disorder that worsens over time. It involves a gradual loss of memory, as well as changes in behavior, thinking and language skills. Alzheimer’s disease is the most common form of dementia.
Although each person with Alzheimer’s disease experiences the disease differently, its typical course can be divided into a series of 5 stages. However, it is essential to ensure that a person with dementia has a good quality of life with the disease and that their needs are met, rather than focusing on the stage they may have reached.
The 5 stages of Alzheimer’s disease
Alzheimer’s disease mainly affects older people and usually develops over a number of years. Looking at Alzheimer’s disease in stages can give a clearer picture of the possible changes that could affect a person after they are diagnosed. Stadiums can only be a rough guide and experts have come up with many different ‘stadium’ systems over the years. Some people consider the disease to have seven stages, while others speak of only three. The symptoms that appear and when they appear vary from person to person.
In this article, we discuss Alzheimer’s disease in five stages:
Stage 1: preclinical Alzheimer’s disease
Stage 2: mild cognitive impairment due to Alzheimer’s disease
Stage 3: mild dementia due to Alzheimer’s disease
Stage 4: moderate dementia due to Alzheimer’s disease
Stage 5: severe dementia due to Alzheimer’s disease
Dementia describes a collection of symptoms that affect memory, thinking, problem solving or language. In a person with dementia, these symptoms are severe enough to affect daily life.
Stage 1: Preclinical Alzheimer’s disease
Functional changes due to Alzheimer’s disease can begin years or even decades before diagnosis. This long phase is known as the preclinical stage of Alzheimer’s disease. During this stage, the person has no noticeable clinical symptoms. Although there are no visible symptoms in the preclinical stage, imaging technologies can spot deposits of a protein called beta-amyloid.
In people with Alzheimer’s disease, this protein clumps together and forms plaques. These clumps of protein can block intercellular signaling and activate immune system cells that trigger inflammation and destroy damaged cells. Other biological markers, or biomarkers, can indicate whether a person is more likely to develop symptoms of Alzheimer’s disease. Genetic testing can also detect a higher risk. Imaging technology that can locate beta-amyloid clusters, biomarker detection and genetic testing could all be important in the future as scientists develop new treatments for Alzheimer’s disease.
Researchers are studying this preclinical stage to determine which factors may predict the risk of progression from normal cognition to stage 2 Alzheimer’s disease. The researchers also hope their studies will help people with Alzheimer’s disease access treatment at an earlier stage. Disease-modifying therapies may be more effective in the early stages of Alzheimer’s disease, and they may slow disease progression.
Stage 2: Mild cognitive impairment
Both advanced age and Alzheimer’s disease can lead to forgetfulness, but not everyone develops dementia as they age. Mild cognitive impairment (MCI) is a greater cognitive decline than occurs in the normal part of aging, but it occurs before the more severe decline of dementia. Between 15 and 20 percent of people age 65 or older have MCI. It is important to note that not everyone with MCI will develop dementia. About 10 to 15 percent of people with MCI develop dementia each year.
A person with MCI may notice subtle changes in their thinking and ability to remember things. She may have memory lapses when trying to remember recent conversations, events, or appointments. However, the changes in memory and thinking are not severe enough at this stage to cause problems with daily living or usual activities. It’s normal for people to become more forgetful as they get older or take longer to think of a word or remember a name. However, if a person is having significant difficulty performing these tasks, it may be a sign of MCI.
Symptoms of DCL are as follows
– forgetting things more often
– forget appointments, conversations or recent events
– inability to make decisions or feeling overwhelmed when doing so
– an increasing inability to gauge the passage of time or the sequence of steps to complete a task
– being more impulsive or showing less and less judgment
– the changes become noticeable to friends and family.
– People with MCI may also experience depression, irritability, aggression, apathy and anxiety.
As of now, no medication or therapy has been approved to treat MCI. However, studies are underway to identify treatments that may help improve symptoms or prevent or delay their progression to dementia.
Stage 3: Mild Dementia
The stage of mild dementia is when doctors usually diagnose Alzheimer’s disease. In addition to becoming noticeable to friends and family, problems with memory and thinking can also begin to affect day-to-day life.
Symptoms of mild dementia due to Alzheimer’s disease include:
– difficulty remembering newly learned information
– ask the same question several times
– difficulty solving problems and completing tasks
– decreased motivation to complete tasks
– loss of judgment
– unusual withdrawal or irritability or anger
– difficulty finding the right words to describe an object or an idea
– getting lost or misplacing objects.
Stage 4: Moderate Dementia
When a person has moderate dementia due to Alzheimer’s disease, they become increasingly confused and forgetful. She may need help with daily chores and looking after herself.
Symptoms of moderate dementia due to Alzheimer’s disease are:
– loss of bearings and forgetting the path, even in familiar places
– wander in search of an environment that seems more familiar
– not remembering the day of the week or the season
– confusing family members with close friends or mistaking strangers for family members
– forget personal information, such as address, telephone number and study history
– repeat favorite memories or invent stories to fill in memory gaps
– need help deciding what to wear depending on the weather or season
– need help with bathing and toileting
– occasional loss of bladder or bowel control
– distrusting friends and family unduly
– see or hear things that are not there
– fidget or be fidgety
– have outbursts of anger, which can be aggressive.
Stage 5: Severe dementia
Over time, the person with Alzheimer’s disease will need more care and help with everyday tasks.
At this point, mental functioning continues to decline, while movement and physical abilities may deteriorate significantly.
Symptoms of severe dementia due to Alzheimer’s disease include:
– an inability to speak and communicate coherently
– the need for full assistance with personal care, feeding, dressing and using the toilet
– an inability to sit up, hold your head up, or walk unaided
– rigid muscles and abnormal reflexes
– loss of ability to swallow
– inability to control bladder and bowel movements.
A person with a severe form of Alzheimer’s disease has a high chance of dying from pneumonia. Pneumonia is a common cause of death in people with Alzheimer’s disease because loss of the ability to swallow means food and drink can enter the lungs and cause infection.
Other common causes of death in people with Alzheimer’s disease are dehydration, malnutrition and other infections.
Not everyone experiences the different stages of Alzheimer’s disease in the same way, and the rate and extent of progression depends on each person. A person may not have all of the symptoms mentioned above, and specific symptoms, such as aggression, may appear for a short time and then disappear. Stages can also overlap.
Factors that can affect disease progression include:
Age: People whose symptoms of Alzheimer’s disease develop before the age of 65 may have a faster progression.
Genetic factors: A person’s genes can affect how quickly the disease progresses.
Physical health: People who have poorly managed heart problems, diabetes or recurrent infections and those who have suffered multiple strokes may see their condition deteriorate more quickly.
Staying active, participating in activities and exercising regularly can help the person retain their abilities for longer.
Other lifestyle changes may help slow disease progression:
– maintain a healthy diet
– stay mentally and physically active
– get enough sleep
– take all prescribed medications correctly
– stop smoking
– limit or avoid alcohol consumption
– have regular health checks.
If a person with Alzheimer’s disease experiences a sudden change in their abilities or behavior, they could have another health problem or an infection. It is essential to seek the advice of a doctor as soon as possible.
The average life expectancy for someone with Alzheimer’s disease is 3 to 11 years after diagnosis, but people can live with Alzheimer’s disease for 20 years or more. If symptoms appear before the age of about 75, the person is likely to live another 7 to 10 years after diagnosis. On the other hand, if the symptoms appear at the age of 90 or more, the lifespan is about 3 years.
* Presse Santé strives to transmit medical knowledge in a language accessible to all. In NO CASE can the information given replace medical advice.