Alzheimer’s disease is one of many forms of dementia, a type of memory impairment that disproportionately affects older individuals. The Alzheimer’s Organization estimates that nearly six million Americans have Alzheimer’s disease, with five million over age 65.
While Alzheimer’s can affect any older adult, the majority of individuals with Alzheimer’s dementia are women, making up nearly two-thirds of individuals living with Alzheimer’s. African Americans and Hispanics are also more likely to get Alzheimer’s than Caucasians. Alzheimer’s disease is also a leading cause of death in the U.S., just behind cancer, heart disease, stroke and accidental injuries.
What is Alzheimer’s Disease?
Alzheimer’s disease is a progressive brain disorder that affects older individuals. It causes a gradual, irreversible breakdown of cognitive function that hurts thinking skills, memory and the ability to perform even simple tasks.
Alzheimer’s was first noted in the medical community over a hundred years ago when Dr. Alois Alzheimer documented a female patient who died of an odd “mental illness”. He noted her unpredictable behavior, loss of memory and problems with speech. Dr. Alzheimer conducted an autopsy on this woman and discovered what we now know as one of the classic signs of Alzheimer’s – beta-amyloid plaques and neurofibrillary (tau) tangles intertwining with brain tissue. Beta-amyloid plaques and tau tangles interfere with cognitive abilities resulting in many of Alzheimer’s patients’ symptoms.
But what caused these “plaques and tangles” to form in the brain of Dr. Alzheimer’s patient? Research concerning Alzheimer’s disease remained limited until breakthroughs in the 1980s allowed scientists to identify the beta-amyloid protein responsible for widespread nerve cell damage in the brain. Two years later, scientists identified the tau protein causing nerve cell degeneration and “tangles” indicative of Alzheimer’s disease.
What Causes Alzheimer’s Disease?
Dr. Alzheimer’s, for whom the disease is named, was on the right track when he identified the plaques and tangles in his patient. However, even today, the cause of Alzheimer’s is not fully understood. The medical community does not know what causes amyloid plaques or tau tangles to occur, for example.
The amyloid precursor protein (APP) is a membrane protein that can be found in many different tissues. It’s especially concentrated in neurons, and while researchers have yet to pin down its primary function, it may play a role in forming synapses in the brain, maintaining neural plasticity and even exporting iron.
Plaques form when the amyloid precursor protein starts to break down. Beta-amyloid protein collects in clumps between neurons where they disrupt cell signaling. Development of amyloid plaques typically precedes Alzheimer’s symptoms involving behavior and personality changes.
While amyloid plaques collect outside brain cells, neurofibrillary tangles made of “tau” proteins collect inside brain cells. Supported by internal microtubules that transport nutrients to dendrites and axons, neurons rely on tau protein to stabilize microtubules and prevent them from collapsing. Alzheimer’s disease causes chemical disruptions that force tau molecules to separate from microtubules and adhere to tau molecules. The resulting thread-like tangles form inside brain cells and interfere with the ability of neurons to communicate.
Symptoms of Alzheimer’s disease emerge from the interaction between beta-amyloid proteins and accumulation of tau in the brain. Tau “tangles” grow in regions of the brain involved in memory while plaques develop between brain cells. Scientists think as plaques accumulate and reach a certain level of pervasiveness, the spread of tangles also increases rapidly throughout the brain.
Inflammation in the Brain and Alzheimer’s Disease
Another component of Alzheimer’s disease is the glial cell. Glial cells are like the brain’s “trash removers,” constantly scouring the brain in search of toxins and waste to consume. However, Alzheimer’s patients’ glial cells do not remove debris. This allows accumulation of proteins like beta-amyloid plaques to overwhelm the brain. Researchers still do not know what causes glial cells to malfunction in Alzheimer’s patients.
Inflammation produced by excessive brain waste may promote development of Alzheimer’s. To learn more, researchers are focusing on the TREM2 gene, a gene that “directs” glial cells to remove plaques and eliminate inflammation. When this gene isn’t working properly, beta-amyloid plaques accumulate between brain cells. A subtype of glial cells called astrocytes assist other glial cells with removing debris and plaques. An abnormal TREM2 gene somehow prevents glial cells and astrocytes from performing their duties as brain “cleaners.” In addition, these two cell types also release inflammatory chemicals that further damage brain cells in people with Alzheimer’s.
Normal aging comes with naturally declining levels of memory-supporting proteins and hormones, deterioration of the hippocampus and decreased blood flow to the brain. These three things combined with other age-related health problems will cause lapses in memory that are only to be expected in older individuals.
Alzheimer’s disease, on the other hand, brings more severe, or accelerated memory loss and cognitive decline. While it is normal to occasionally forget where you laid your keys or if you locked the door, memory and cognitive disruptions associated with Alzheimer’s disease will worsen and eventually impacts a person’s ability to take adequate care of themselves.
People with early or middle-stage Alzheimer’s disease may:
- Repeat things and claim they never said them
- Insist appointments were never made or conversations never happened because they cannot remember them
- Place possessions in odd places, like putting keys in the refrigerator or a wallet in the laundry hamper
- Become disoriented in familiar locations
- Have difficulty finding appropriate words to express their thoughts, identify items or contribute meaningfully to conversations
- Act depressed, withdrawn and apathetic towards hobbies and events they used to enjoy
Personality and Behavioral Changes
People with various forms of dementia, including Alzheimer’s disease will naturally become irritable, distrustful and agitated as their memory and cognitive decline worsens. It is hard to accept the fact they cannot remember something someone said just five minutes ago or realize they did indeed put their checkbook in the microwave.
A person with Alzheimer’s who has always thought carefully about making decisions all their life may start making impulsive, irrational decisions that bewilder family members and friends. They may wear sweaters in hot weather or shorts and t-shirts in cold weather. Their responses to everyday situations, such as what to do if they drop a glass or who to call if the roof starts leaking are often confused and inappropriate. For example, instead of sweeping up broken glass into a dustpan, a person with Alzheimer’s may try to use a vacuum to pick up large, jagged pieces of glass.
Physical Signs of Alzheimer’s Disease
Physical symptoms of Alzheimer’s typically emerge during the middle stages of the disease. They include:
- Problems with movement as neuron signaling in the brain degrades in areas controlling motor ability
- Difficult standing still
- Walking and balance issues
- Inability to button shirts, write legibly or perform other tasks involving fine motor skills
- Engaging in repetitive behaviors such as handwringing, face-picking or washing the same dish over and over again
- Problems with bladder/bowel control
- Hand tremors/shaking
Most people with Alzheimer’s do not experience vision disturbances. One uncommon type of dementia called posterior cortical atrophy (PCA) can cause vision problems when plaques and tangles degrade the occipital lobe. Brain imaging scans are necessary to determine if PCA is caused by Alzheimer’s or another type of dementia, such as corticobasal degeneration or dementia with Lewy bodies.
The Seven Stages of Alzheimer’s Disease
Created by Dr. Barry Reisberg, the Global Deterioration Scale is a standardized method of determining what stage of AD is affecting an individual.
Stage 1 is “normal”. While Alzheimer’s may be building up in the body, there are no physical or mental symptoms at this stage.
Stage 2 is “normal aged forgetfulness” characterized by cognitive problems experienced by most people over age 65.
Stage 3 is “mild cognitive impairment.” Symptoms of being in Stage 3 include repeating questions, disturbances in executive functions (self-control, working memory, flexible thinking) and reduced ability to concentrate or engage in organized thinking.
Stage 4 is “mild Alzheimer’s disease.” People at this stage have difficulty managing their own finances, preparing meals for others, remembering the correct date and become disoriented in familiar places. Alzheimer’s patients typically spend about two years at Stage 4, although the disease progresses at a different rate for every individual.
Stage 5 is “moderate Alzheimer’s disease.” At this point, the person will need memory care and round-the-clock supervision. Cognitive impairment is clearly noticeable. Stage 5 Alzheimer patients may be unable to remember their address or names of close relatives. They may think it is a year in the past and not the current year.
Stage 6 is “moderately severe Alzheimer’s disease.” At this stage, the person needs someone to pick out their clothes and assist them in putting them on. They need help bathing, brushing teeth and other personal hygiene tasks. Although someone with Stage 6 Alzheimer’s may be physically able to dress and bathe without assistance, they are cognitively unable to choose the appropriate clothing, adjust water temperature to ensure they do not burn themselves or remember to brush their teeth.
Emotional and personality changes become disturbing at this stage. Individuals begin pacing, fidgeting and randomly moving objects to places they do not belong due to cognitive deficits preventing them from utilizing their energy productively. Individuals with stage 6 Alzheimer’s are often aware of what is happening to them and may express their shame, agitation and fear by verbally or physically attacking others. The average duration of Stage 6 symptoms is a little over two years.
Stage 7 is “severe Alzheimer’s disease.” Patients require 24/7 care at this stage. However, it is uncommon for Alzheimer’s patients to reach the final stage. Typically, by the time a person reaches Stage 6, they have passed due to a heart, lung or other systemic health problem that their Alzheimer’s disease made them more vulnerable to.
Factors Influencing Progression and Lifespan
The average lifespan of people over 65 who are diagnosed with Alzheimer’s ranges from eight years to as long as 10+ years. Studies investigating why some people with Alzheimer’s live longer than others found several factors influencing shorter survival rates:
- Being male (while more women are diagnosed with Alzheimer’s, men with Alzheimer’s tend to live shorter lives)
- Unsteadiness when walking
- Severe wandering behavior
- Level of incontinence
- Low scores on mental abilities tests
- Having diabetes or heart disease prior to a diagnosis of dementia
Alzheimer’s patients who present a rapid and noticeable decline in their mental and physical health during the first year of their diagnosis also tend to have shorter life spans. Moreover, some patients respond well to Alzheimer’s treatment programs (medication combined with a healthy diet and remaining physically and mentally active) while others require assisted living and memory care services earlier than others, even with treatment.
What are Risk Factors for Alzheimer’s Disease?
Since we still haven’t pinpointed the cause of Alzheimer’s, risk factors are still not solidified. However, researchers have identified several components.
Age, genetics, family history of Alzheimer’s disease, being female and having certain medical conditions like Parkinson’s, HIV or multiple sclerosis are non-modifiable risk factors. In other words, these risk factors are permanent.
Modifiable risk factors for Alzheimer’s (factors that can be changed) include type 2 diabetes, suffering from major depression, smoking, sedentary lifestyle, mid-life hypertension and obesity and lower educational status. Some weak evidence exists that points to diet, cognitive activity, chronically poor sleep and experiencing traumatic events in childhood as possible risk factors for Alzheimer’s.
How is Alzheimer’s Disease Diagnosed?
Unfortunately, there is no surefire way to diagnose Alzheimer’s while an individual is alive. The only definitive diagnosis comes from autopsies. However, there are tests that physicians can use to make a likely diagnosis.
If a doctor suspects someone has Alzheimer’s, they will order laboratory tests to rule out other possible causes of cognitive decline. CT and MRI brain scans can identify lesions and tumors on the brain that may be causing symptoms similar to those of dementia. Positron emission tomography (PET) scans user tracer chemicals to identify brain regions that are functioning abnormally. In most cases, PETs are necessary for doctors to correctly diagnose Alzheimer’s since this type of scan pinpoints exact brain areas implicated in Alzheimer’s.
Cognitive examinations evaluate memory, reasoning ability, sense of time and sense of place. An example of a question on a cognitive status test would be asking the person to draw the face of a clock showing a specific time. Another task would be to have the person determine how much money they have if they are given two quarters, two dimes, a nickel and five pennies.
Other Alzheimer’s tests used in clinical settings include the Mini-Mental State Examination, the Alzheimer’s Disease Assessment Scale (Cognitive Section) and the Cambridge Assessment of Memory and Cognition.
Treatments for Alzheimer’s Disease
Alzheimer’s cannot be cured, but medication can help slow its progression or improve quality of life for those living with the disease.
Medications that impede degradation of a neurotransmitter called acetylcholine (ACh) are the standard Alzheimer’s treatment. The FDA has approved cholinesterase/acetylcholinesterase inhibitors for reducing Alzheimer’s symptoms and delaying progression of the disease. ACh is essential for healthy nerve signaling, normal motor control, cognition and memory.
Other treatment methods may involve holistic wellness routines that encourage individuals with Alzheimer’s to remain physically, mentally, spiritually and socially active. By exercising their brains and keeping the physical body in good shape, individuals can help slow the progression of their disease to live a healthier life for longer.
Memory Care for Individuals with Alzheimer’s
Unfortunately, the progressive, incurable nature of Alzheimer’s disease makes it a difficult diagnosis to live with. Many individuals live strong lives in their own homes at the start of the disease but as symptoms progress, they typically need full-time care to live a full life.
At The Landings at Norcross, we believe every person with Alzheimer’s can still live a full life by focusing on her or his strengths. Our memory care community makes that possible by providing the support individuals with Alzheimer’s need to make the most of their abilities. Contact us for more information on our community or if you have any questions about Alzheimer’s disease. We’re here to help.