In this article, we will explore what exactly is Alzheimer's disease and what causes the neurons in an apparently healthy nervous system to breakdown and turn into mush. We will also explore how the disease progresses from milder (barely noticeable) stages into the most severe form - where your loved ones have a hard time recognizing familiar faces and treasured moments. Lastly, we will also explore a range of support options that await you as a loved one to help improve the quality of your life as a caregiver and also the care recipient.

What is Alzheimer's disease?

Alzheimer's disease is a nervous system disorder that is characterized by irreversible, progressive, degenerative destruction of cortical neurons leading chiefly to a triad of symptoms including:

Aphasia (inability to speak)

Agnosia (loss of the ability to recognize faces, objects, voices, or places)

Apraxia (inability to carry out purposeful learned task like, driving, dressing etc)

The hallmark of Alzheimer's disease is memory loss. Alzheimer's is the leading cause of dementia in individuals over 65 and has lately been recognized as an inevitable age-related generative process rather than a disease since over 5.8 million individuals in the U.S age 65 and older are diagnosed with Alzheimer's disease. Among these individuals, 80% are 75 or over. Approximately 50 million people suffer from with dementia worldwide - of which 60% and 70% are estimated to have an Alzheimer's disease related origin.

Since Alzheimer's typically causes death of neurons in the region of cerebral cortex, the symptoms range from loss of memory, problem-solving abilities, ability of plan and execute purposeful tasks, complex thinking pathways, language deficits, personality changes, and lack of judgment.

 

What Causes Alzheimer's Disease?

Most pathological studies point towards abnormal build-up of proteins in and around neurons as the etiology of developing of Alzheimer's disease.

The most notorious protein implicated in the brain damage is called amyloid. Amyloid deposition results in formation of plaques around the brain cells that result in cell death and loss of healthy brain tissue. Several studies have also implicated deposits of tau protein which form tangles within brain cells.

Age is an independent risk factor for Alzheimer's disease however, studies have yet to find why the disease process begins in elderly individuals in the first place.

As brain cells begin to die secondary to neurofibrillary tangles and amyloid deposition, it brings about a deficiency in the circulating chemical messengers within the brain (called neurotransmitters). Neurotransmitters are responsible for effective communication between the brain cells. Studies have revealed significantly lower levels of neurotransmitter Acetylcholine in individuals with AD, which has become a novel targeted pathway to intercept the symptoms of AD through drugs that increase or prevent breakdown of acetylcholine in the central nervous system.

The first area to be affected by these histological changes is amygdala and hippocampus region which plays a role in long-term memory. Later areas of frontal and parietal cortex are involved resulting in aphasia (inability to speak) and agnosia (inability recognize familiar objects and faces) occur.

Some risk factors that have been implicated in the development of disease include age, family history, Down's syndrome, obesity, smoking, hypertension, high blood pressure, a sedentary lifestyle and lack of social support system. However, a great deal of research of research is still underway to unearth the development of AD.

What Stages Does the Disease Progress in?

Alzheimer's disease runs a significantly slow and gradual course and symptoms tends to develop, progress and worsens over several years. Eventually, most areas of the brain begin showing changes representing Alzheimer's disease.

The symptoms can broadly be identified to progress in not-very-well-defined five stages: preclinical stage, mild cognitive impairment secondary to AD, mild dementia due to AD, moderate dementia due to AD and finally progressing into a severe, irreversible form of dementia. Dementia describes a hoard of symptoms that impair an individual's intellectual and social abilities severely enough to affect quality of life and daily life functions.

These five clinical stages of Alzheimer's stages can help you understand and anticipate the progression for a loved one, however, what's important is that these stages only represent generalization of a continuous disease process. And each patient has a unique experience with Alzheimer's and its symptoms, which is why care plans may vary from person to person and have to be carefully tailored around the needs of your loved one.

Here are the five stages of Alzheimer's Disease:

1. The Barely Noticeable Preclinical Stage

Research has revealed that pathological changes within the brain tissue begin long before any symptoms become apparent. This silent stage of developing histological changes within the brain is called preclinical Alzheimer's disease, and it's usually recognized only in candidates undergoing a research study. The patient will be leading a healthy, symptom-free life during this phase and those around them won't notice any change of behavior.

Radiological Changes

It is estimated that histological changes can take years, possibly even decades before they start exhibiting symptoms. In candidates participating in a research study, it is now possible with the use of newer brain imaging modalities to now identify amyloid-beta deposits - the hallmark of Alzheimer's disease. The ability to pick up these deposits in the pre-clinical stage can unlock a futuristic scope for clinical trials for the development of novel treatments that halt the disease process or possibly even reverse it.

Biomarkers

In recent years, scientists have been able to reveal certain biomarkers that are released into the blood and can be measured to indicate the increased risk of disease development/progression. These biomarkers can be used to establish the diagnosis well before symptoms appear and administer cerebroprotective drugs before the irreversible changes takes over.

Genetic Testing

Genetic tests also have a role in determining a higher risk of Alzheimer's disease, particularly in the setting of early-onset disease. They are not a part of diagnosis for everyone, however, they can be conducted in individuals with a highly-suggestive family history after discussing with your doctor.

2. Stage of Forgetfulness - the Mild Cognitive Impairment (MCI)

As the name indicates the stage comprises of milder but noticeable changes in the memory, thinking ability and behavior of affected individual. However, the hallmark of this stage is preserved quality of life and day-to-day life functions. The disease won't affect work or relationships, thus, is often overlooked as a side-effect of stress. MCI causes people have memory lapses particularly with information that is usually easily remembered by their healthier counterparts. This can range from conversations, to recent happening or scheduled appointments.

A particularly interesting facet of MCI is people will have trouble estimating the amount of time required to complete a familiar task or they might find it challenging to recall the sequence or number of phases required to achieve a task. The ability to undertake intellectually-sound decision can become impaired to a certain degree during MCI.

While it is important to identify the symptoms of Mild cognitive impairment, it is also important to know that not everyone with mild cognitive impairment will progress to develop Alzheimer's disease. The diagnosis of MCI stems from your physician's review of your presenting complaints and professional judgment. However, if there is any obscurity concerning the diagnosis, the methods implicated in the identification of preclinical Alzheimer's disease stand relevant in establishing whether MCI is secondary to Alzheimer's disease or another type of dementia.

3. Stage that Impacts Daily Functioning: Mild dementia

This is the stage where more than 50% of the diagnoses are established. This is because since day-to-day functioning is preserved up until this stage, it only becomes apparent with this stage to loved ones that a person is experiencing sufficient impairment with memory and thinking to affect daily functioning and quality of life.

The milder form of dementia may cause people to experience:

Inability to remember recent events

This refers to a significant impairment in recalling and recollecting newly-learned information. The person might ask the same question repeatedly.

Inability to carry out purposeful complex tasks, problem-solve or make sound judgments

Leaned tasks like organizing an official event or balancing a checkbook that a person has been familiar to do since ages, will start to overwhelm him. People around him will notice and point out lapses in judgment, like conducing a financial deal.

Personality and behavior change

Individual may experience co-occurring mental disorders like depression and anxiety and become subdued withdrawn-particularly in socially challenging circumstances. They may exhibit irritability or anger secondary to cognitive impairment as they lack insight of the ongoing disease process. All of this may contribute to reduced motivation to complete daily tasks.

Inability of organization and expression of thoughts

As the damage progresses to the frontal and parietal lobes, it starts to affect the thought process, and chief areas of brain like Broca's and Wernicke's involved in understanding, organizing and expression of ideas through speech. As the aphasia progresses, people will find it challenging to describe objects or clearly express ideas.

Loss of orientation to place

People will occasionally find themselves lost and unable to find their way around, even in familiar places. Family will start noticing a pattern of losing or misplacing things, including treasured belongings.

4. Moderate dementia due to Alzheimer's disease

As people progress from a milder form to a moderate stage of dementia they become increasingly confused and forgetful and become dependent on their loved ones to carry-out daily life activities like bathing, medication, and choosing outfits.

The moderate stage comprises of:

Marked lack of judgment and profound confusion

The hallmark of this stage is marked disorientation to time, place and person. This means losing track of where they are, dates, months or seasons. With marked disability to recognize faces, they will start confusing family members or acquaintances with one another or mistake strangers for familiar faces.

Wandering becomes common and it is thought to be in search of familiar surroundings

These features characterize this stage as a fully-dependent stage and people with moderate dementia stage, on their own, can put themselves in unsafe situations.

Profound, Noticeable, Debilitating memory loss

It is characterized by forgetting their personal details, like their address or phone number, or name of their school or the town where they were born. A particularly important symptom is confabulations where a person will make up stories to fill the gaps in their memory.

Assistance with some daily activities

They become increasingly dependent on loved ones to carry out daily life functions like picking appropriate clothing for a certain event or the weather. Out of bed mobilization becomes difficult and help needed for grooming, bathing, using the bathroom and self-care activities. There can be occasional loss of bowel and bladder control.

Developing Hallucinations and Delusions

People with the moderate dementia frequently experience hallucinations and delusions. This might consist of unsubstantiated suspicions -like becoming convinced that a loved one or a caregiver is stealing from them or that a spouse is cheating on them despite satisfactory evidence suggesting otherwise. They may develop visual or auditory hallucinations - seeing or hearing things that aren't there.

People can show symptoms of anxiety or depression, become agitated or restless, particularly as the day progresses. Some may exhibit aggressive physical behavior or violent outbursts.

5. Severe dementia leading to complete dependence

In the later and the most severe stage of Alzheimer's disease, mental function declines to a certain degree that a person becomes completely agnostic, apraxic and aphasic - leading to complete dependence.

The severe stage is characterized by:

Aphasia

This refers to initiating and holding a meaningful conversation. The person can no longer converse or interact coherently. However, most of them will still have brief periods of memory comebacks where they say meaningful words or phrases.

Assistance with personal care

The person becomes completely dependent for their daily life activities like eating, medication schedule, dressing, using the bathroom, self-grooming, out of bed mobilization and other daily life tasks.

Loss of Motor Function

There is a progressive loss of chief motor functions in this stage as a person becomes unable to walk without assistance, then inability to sit or holding up head without support. There may be some muscle rigidity and abnormality in reflexes. The extremely advanced stages also represent a weakness of swallowing muscles and inability control bowel and bladder functions.

 

What is the Rate of Progression through these stages?

There is a wide variation when it comes to the rate of progression for Alzheimer's disease. It is chiefly determined by genetic and environmental factors. The approximate lifespan ranges between 3 and 11 years after a diagnosis has been established, but survival rates as long as 20 years or more have been reported. Life expectancy is significantly affected by degree of impairment at the time of diagnosis.

The Medical Treatment for Alzheimer's Disease

The current mainstay of medical treatment for mild Alzheimer's disease is Acetylcholinesterase inhibitors. These drugs include Rivastigmine, Galantamine and Donepezil. They work by inhibiting the enzyme involved in the breakdown of acetylcholine, thereby increasing the concentration of acetylcholine within the central nervous system. You must recall from the section of pathogenesis that decreased levels of acetylcholine represent milder forms of dementia.

In the later stages, although nothing can reverse the disease process, a number of drugs have proven to be effective in managing behavioral problems. These include NMDA (N-methyl D-aspartate) antagonists, for example, Memantine and glutamate regulators. Symptomatic treatment for behavioral problems like anxiety, depression, insomnia, hallucinations and delusions can also be prescribed. However, treatment response should be closely monitored as individuals with Alzheimer's are more prone to develop side-effects with sleeping aids, anticonvulsants, anxiolytics, antidepressants, and antipsychotics.

Supportive Treatment for Alzheimer's disease

The supportive treatment for Alzheimer's comes in the form of therapy and care assistance. There are various form of therapies that a person or caregiver can opt for in order to better equip themselves to handle the disease progression. These include Crisis intervention counseling to help you get through a crisis, or Family therapy to help you make financial decisions with your loved ones and determine who will be in charge of your care considering the emotional consequences of long-term care giving. You can also become a part of self-help or support groups to help you understand anticipate and deal with the challenges associated with Alzheimer's.

There are multiple of care options that include in-home care and nursing homes. This is mainly decided upon the degree of disability a person has and the preferences of long-term care.

What are the Chief Causes of Death in an Alzheimer's Patient?

Aspiration and aspiration pneumonia continues to be a the leading cause of death in Alzheimer's patients as swallowing and coughing reflexes are impaired allowing food to enter the respiratory passage. This can either lead to immediate death to development of aspiration pneumonia that is infection of the lung secondary to food particles. Other common causes of death range from dehydration, malnutrition, falls and infections due to restricted mobility and other co-morbidities including diabetes and hypertension.