What is Alzheimer’s Disease?
Alzheimer’s disease is a disease that causes the brain to physically atrophy. It can occur in middle or old age and results in symptoms of forgetfulness and cognitive impairment known as dementia. (For more about dementia please read my article Diagnosing Dementia).
Alzheimer’s disease is the most common cause of dementia. Dementia caused by Alzheimer’ disease is known as ‘Dementia of the Alzheimer’s type’, or simply ‘Alzheimer’s’.
How Does Alzheimer’s Disease Progress?
Every person with Alzheimer’s disease experiences the disease differently, but there does seem to be a similar progression of the disease for most patients and it can be described in a series of stages. The precise number of stages is somewhat arbitrary. Some experts use a simple three-stage model (mild/early; moderate/middle; severe/late), while others use a five, six or seven-stage model. Progression through these stages usually lasts from eight to ten years, but can sometimes last as long as twenty years.
It is important to be aware that the stages don't always fall into neat boxes. As mentioned above, each individual with Alzheimer’s progresses differently - cognitive, physical, and functional phases often overlap, the time in each stage varies widely from patient to patient, and not everyone experiences all Alzheimer’s symptoms. The stages do, however, provide a general guideline for understanding the progression of Alzheimer’s symptoms and for planning appropriate care.
The most common system, developed by Dr. Barry Reisberg of New York University, breaks the progression of Alzheimer’s disease into seven stages. It is known as the Seven Stage Global Deterioration Scale, or the Reisberg Scale, and is described below.
Seven Stage Global Deterioration Scale
Stage 1: No Impairment
During this stage, Alzheimer’s disease is not detectable and memory and cognitive abilities appear normal. A PET scan may show brain abnormality.
Stage 2: Minimal Impairment/Normal Forgetfulness (Very Mild Decline)
The person may notice minor memory problems, such a forgetting a word or misplacing objects, but memory lapses and changes in thinking are rarely detected by friends, family, or medical personnel, especially as about half of all people over 65 begin noticing problems in concentration and word recall. (In other words, the symptoms might not be Alzheimer's at all, but simply normal changes from aging).
At this stage, the subtle symptoms of Alzheimer's don't interfere with a person’s ability to work or live independently.
Stage 3: Mild Cognitive Impairment/Early Confusional (Mild Decline)
Duration: 2 to 7 years.
At this stage memory and cognitive problems become noticeable. Performance on memory and cognitive tests are affected and physicians will be able to detect impaired cognitive function.
The person may consciously or subconsciously try to cover up his or her problems.
Patients in stage three of Alzheimer’s disease will have difficulty in many areas, which can affect life at home and work, including:
- Difficulty in finding the right word during conversations.
- Difficulty remembering names of new acquaintances.
- Frequently loses personal possessions, including valuables.
- Forgets something they have just read or recently learned.
- Asks the same question over and over.
- Has more and more trouble making plans or organizing.
Depression and other changes in mood can also occur.
You can help, by being your loved one's "memory" for them. For example, you can make sure they pay their bills and get to appointments on time. You can also suggest they ease stress by retiring from work and putting their legal and financial affairs in order.
Stage 4: Mild Alzheimer’s/Late Confusional (Moderate Decline)
Duration: Approximately 2 years.
At this stage clear cut symptoms of Alzheimer’s disease are apparent and accurate diagnosis of Alzheimer’s disease is possible.
Although most people in this stage still know themselves and their family, recent events and conversations are increasingly forgotten.
Patients in stage four of Alzheimer’s disease:
- Have difficulty with simple arithmetic and so problems managing finances arise. (For example, they are unable to pay bills and may have trouble putting the right date and amount on a cheque).
- Forget details about themselves (for example, their life history).
- Forget what month or season it is.
- Have poor short term memory (for example, forget what they ate for breakfast).
- Have problems carrying out sequential tasks, including cooking, driving, ordering food at restaurants and shopping.
You can help with everyday chores and safety. Make sure they don’t drive and that someone isn't trying to take advantage of them financially.
Stage 5: Early Dementia/Moderate Alzheimer’s Disease (Moderately Severe Decline)
Duration: Approximately 1.5 years.
During the fifth stage of Alzheimer’s, patients begin to need help with many day to day activities, although they maintain a modicum of functionality. Typically, they can still bath themselves and use the toilet independently. They usually still know their family members and some detail about their personal histories, especially their childhood and youth.
People in stage five of Alzheimer’s disease may experience:
- A severe decline in numerical abilities and judgment skills, which can leave them vulnerable to scams and at risk from safety issues.
- Significant confusion. For example, they might start to lose track of where they are and what time it is.
- Difficulty recalling simple details about themselves such as their address, phone number, or where they went to school.
- Difficulty dressing appropriately. For example, they may get confused about what kind of clothes to wear for the day or season.
You can help by laying out their clothing in the morning. This can help the patient to dress themselves and keep a sense of independence.
If they repeat the same question, answer with an even, reassuring voice. They might be asking the question less to get an answer and more to just know you're there.
Even if your loved one can't remember facts and details, they might still be able to tell a story. Invite them to use their imagination at those times.
Stage 6: Middle Dementia/Moderately Severe Alzheimer’s Disease (Severe Decline)
Duration: Approximately 2.5 years.
People in this stage progressively lose the ability to take care of daily living activities like dressing, toileting and eating, but are still able to respond to nonverbal stimuli, and communicate pleasure and pain via behavior.
Patients with the sixth stage of Alzheimer’s disease need constant supervision and frequently require professional care. Symptoms include:
- Confusion or unawareness of environment and surroundings.
- Inability to remember most details of personal history.
- Inability to recognize faces except closest friends and relatives.
- Many can’t remember close family members, but know they are familiar.
- They might mistake a person for someone else – for example, a man might think his wife is his mother.
- Delusions might set in – for example, a man might think he needs to go to work even though he no longer has a job.
- Major personality changes and potential behavior problems.
- The need for assistance with activities of daily living such as toileting and bathing.
- Loss of bowel and bladder control.
- Agitation and hallucinations often show up in the late afternoon or evening.
- Dramatic personality changes such as wandering or suspicion of family members are common.
It might be hard to talk, but you can help the patient by connecting with them through the senses. Many people with Alzheimer's love hearing music, being read to, or looking over old photos.
Stage 7: Late or Severe Dementia and Failure to Thrive (Very Severe Decline)
Duration is impacted by quality of care and average length is 1 to 2.5 years.
Because Alzheimer’s disease is a terminal illness, patients in stage seven are nearing death. Total support around the clock is needed for all functions of daily living and care. Symptoms include:
- Patients lose the ability to respond to their environment.
- The ability to walk, sit and eat becomes severely impaired.
- Speech becomes severely limited. While they may still be able to utter words and phrases, they have no insight into their condition and need assistance with all activities of daily living.
- Patients may lose their ability to swallow.
You can help by feeding your loved one with soft, easy-to-swallow food, helping them use a spoon, and making sure they drink (this is important, because many people at this stage can no longer tell when they're thirsty).