The Truth About Seven Stages of Alzheimer’s Disease
Alzheimer’s disease is a form of dementia and is, at least in the Western world, the most common form of this type of disease, accounting for 60 to 80 percent of all cases of dementia. Dementia itself can be generally defined as a loss of memory, impairment in cognitive abilities, and related physical decline that progressively impair the affected individual’s daily functioning. We have covered Alzheimer disease comprehensively in this post here, so make sure you have a look at it as well.
While the majority of individuals with Alzheimer’s dementia are aged 65 years and older, it is not considered a normal part of the aging process. Only about 10 percent of individuals aged 65 years or older have the diagnosis of Alzheimer’s disease, with nearly two-thirds of sufferers being female. In addition, while there are about 5.5 million people aged 65 years or older in the US who have the disease, there are still about 200,000 people with Alzheimer’s disease who are under the age of 65 years. These individuals are said to have early-onset Alzheimer’s disease.
The natural course of the disease is that it gets progressively worse over time with an average time from diagnosis to death being four to eight years, although it can last up to twenty years until the individual dies from the disease. Even without another disease or illness in the affected person, Alzheimer’s disease is uniformly fatal by itself, being the sixth most common cause of death in the United States.
Alzheimer’s disease is a microscopic nerve cell disease of the brain. There is a fundamental failure of communication between brain cells that are themselves not operating at full capacity. While there are a lot of theories about what the underlying cause of the disease is, it is known to be partly genetic and to result in irreversible changes in the biochemistry of the brain cells so that they no longer communicate and will no longer function as a whole unit. Evidence of the disease can be seen in the brain even before the clinical signs and symptoms appear.
A Progressive Disease
While each person with Alzheimer’s disease has a unique experience from the beginning to the end of their life, the disease is known to have a similar pathway from mild or no symptoms to extremely severe and life-threatening symptomatology in all sufferers. There are several stages of the disease that are somewhat arbitrary but that can be helpful to know about when trying to understand what happens as the disease progresses. Knowing the different stages can help families and loved ones track the trajectory of the disease in their family member and be able to anticipate the future.
While the disease can be divided into “mild, moderate, and severe” stages, there is a seven-stage model developed by New York University’s Dr. Barry Reisberg, known simply as the Reisberg system. It is the most common system used by the Alzheimer’s Association as well as many healthcare practitioners who help manage Alzheimer’s patients.
In understanding the stages, it is important to recognize that this is a disease that has a one-way progression and that, while an individual can be at a certain stage for a long period of time, they will follow a course that will naturally lead to the next most severe stage over time. This is because, while there are effective treatments that can slow the progression of Alzheimer’s disease, these treatments will only slow the disease progression but will not cure this terminal illness.
Stage 1 Alzheimer’s Disease: No Clinical Impairment
This is the stage of the disease in which there are no clinical findings and no diagnosable memory impairment. In short, there is no detectable disease evident in these patients. This is referred to as “preclinical Alzheimer’s disease”. It is not clinically significant because the individual would not know they have the disease unless they happen to be in a research setting where the disease can be diagnosed using sensitive imaging technology.
The imaging technology can identify protein accumulations in the brain called beta-amyloid deposits, which are not as important to know about practically (yet) because there is no way to intervene on the progressive nature of the disease. For now, this stage is important in clinical trials of drugs and other treatments that might in the future become helpful in stopping the disease before there is clinical evidence of it.
There are also biomarkers for Alzheimer’s disease that identify those who might be at a higher risk of developing it. These biomarkers can be shown to be present in the bloodstream during preclinical disease and there are also genetic tests available for individuals who believe they are at risk for early-onset Alzheimer’s disease. Again, while these will be positive in preclinical disease, they don’t guarantee that a person will develop dementia nor are they seen in every person with known disease.
Stage 2 Alzheimer’s Disease: Very Mild Decline
This involves a minor impairment in memory. Memory loss as well as an inability to remember newly-learned material are the first signs of clinical disease in Alzheimer’s dementia. In this stage, the individual may have difficulty that is beyond that which is seen in age-related memory loss, although the distinction isn’t always obvious. The individual may lose things in the home or forget a phone number, but will pass simple in-office memory tests; the family members may not notice any real decline.
Memories of things in the past are generally completely preserved during this stage. It is the memory involved in learning new material that becomes difficult first. This is because the initial changes are seen in the hippocampus, where newly learned information becomes solidified and remembered for longer periods of time. It will be difficult to learn a new language, the name of a newly met person, or the intricacies of a complex physical task. Working memory is most noticeably affected, which is the type of memory involved in problem-solving.
Stage 3 Alzheimer’s Dementia: Mild Decline
This is the first stage in which the loved ones and family members will begin to notice a slight cognitive decline in the Alzheimer’s disease patient. There will be a further decline in working memory so that things like organization and planning will be affected. There may be a lack of judgement about the time it takes to do a specific task and delays in getting tasks completed. Word-finding difficulties are more common and the memorization of names and dates may be impaired.
This is a stage that can also be referred to as mild cognitive impairment. Work and relationships are not generally affected but there will be some loss of memory around things like the content of recent conversations, remembering appointment times, and the knowledge of recent events. The person’s performance on tasks might be impaired by the inability to remember the sequence of steps necessary to complete them. Decision-making might be compromised.
Outside of memory impairment, there are personality changes that become evident for the first time in this stage. The affected individual may appear to be depressed or withdrawn—not engaging in conversations to the same degree as they normally would have before getting the disease. They may also express increased irritability or may seem angrier than is characteristic for them. There is often a newly-expressed lack of motivation in the area of task completion. Their range of ideas becomes limited during this stage of dementia.
The loss or misplacement of things is increasingly a problem in this stage. Both common and valuable belongings can get lost more frequently. This problem also extends to getting lost while driving, even when traveling in relatively familiar surroundings. The pathways in the brain responsible for simple navigation are increasingly diminished in capacity, making it even more obvious that the impairment is far greater than is seen in the normal aging process.
Stage 4 Alzheimer’s Disease: Moderate Decline
Most people in this stage have an obvious reduction in their cognitive capacities. Things like basic arithmetic problems become difficult to do and there is a greater reduction in the ability to remember activities done even earlier in the same day. Finances usually need to be handled by another family member as basic bill-paying becomes impossible to keep up with.
This is the first time that the individual may forget some things that happened in their early lifetime. They may confabulate in order to cover up their loss of memory. Judgement is impaired and things like the day of the week or even the time of year may be lost to the affected person. This leads to a deeper level of confusion and wandering behavior, particularly as their circle of what is familiar to them closes in.
Because of the confusion seen in this stage, it may be unsafe to let this person live independently or even be left alone for more than a brief period of time. Outside of what’s familiar to them, the individual will be markedly impaired in their ability to function, needing increasing reminders regarding activities of daily living and personal cares. Important details regarding the taking of medications and remembering to eat on a regular basis need to be managed by a consistent person in the patient’s life.
Stage 5 Alzheimer’s Disease: Moderately Severe Decline
Most of the activities of daily living involving the affected person will need ongoing assistance during this phase. Simple things like dressing in an appropriate way will need to be supported. Basic life details, such as the person’s address and phone number, are simply forgotten and the person will need near-total assistance with daily life.
While there is significant confusion outside of what is familiar to them, the patient will still be able to toilet themselves and will need variable degrees of assistance with bathing and grooming. There is the possibility of occasional loss of bowel or bladder function but it is not a consistent problem.
Behavior and personality are significantly affected during this stage. Suspicious thinking is extremely common as the individual will lose trust in those around them. They may hoard food with the belief that someone is stealing from them. Hallucinations, either visible or auditory, can be found in the person in this stage of Alzheimer’s disease. Behavior tends to worsen in the evening, with restlessness, agitation, and verbal or physical outbursts seen at night—a phenomenon called “sundowning”.
Stage 6 Alzheimer’s Disease: Severe Decline
This is the stage in which the Alzheimer sufferer requires ongoing professional care. Constant supervision by a nursing assistant or close family member is usually necessary as the person cannot function on their own in nearly all areas of daily living. Awareness of their surroundings is diminished and there is a decreased ability to recognize the faces of most people, except for close relatives or their spouse. All or nearly all details of the individual’s past are lost to most of these individuals.
Assistance is necessary for all activities of daily living, such as toileting, eating, dressing, grooming, and bathing. There is often complete loss of bowel and bladder function. Wandering behavior is profound if the individual still has the ability to ambulate independently. The recognizable features of the patient’s personality fade away and are replaced by ongoing behavioral issues.
There is a significant impairment of communication during this stage. Carrying on a coherent conversation with others becomes impossible, although they may retain the ability to say a few words or phrases. Physical abilities become affected, with abnormalities in gait being extremely common so that walking without assistance is limited.
Stage 7 Alzheimer’s Disease: Very Severe Decline
This is the final stage of this disease process and is the stage that ends with the death of the individual. There is minimal awareness of the environment and an inability to respond with any type of coherent communication outside of being able to say a couple of words or phrases. This person will require total care with all activities requiring movement, including sitting up independently. The sufferer will have essentially no ability to recognize or respond to loved ones. Almost all aspects of personality are lost in this stage.
The physical impairment now becomes the major threat to the patient’s life. The ability to swallow will be affected so that malnutrition and dehydration become commonplace. This inability to swallow properly can lead to aspiration of swallowed solids and liquids into the lungs. This makes choking experiences increasingly dangerous and the threat of aspiration pneumonia is always high. Bladder infections are also common because of dehydration and poor personal cares. Malnutrition and inactivity lead to skin breakdown and an increased risk of skin infections and decubitus ulcers.
The most common cause of death in this stage is an infection of some kind, although others will ultimately die of dehydration, malnutrition, or even falls. Some patients become so vegetative that eating and drinking become impossible and death comes quickly. Because this stage is always terminal, most of these individuals are not good candidates for tube feeding or other parenteral forms of nutrition.
The treatments available to slow the progression of this disease tend to be most effective in the earlier stages and least effective in those individuals who already have significant impairment in memory and functioning. Research is however continuing in search of medications or other interventions that can be curative of Alzheimer’s disease or that can reverse the disease process during each of these seven stages. Of course, research in preventing this disorder altogether is also ongoing.