What causes Alzheimer's disease?

No one is really sure what causes Alzheimer's disease. Genetics plays a role: about half of the patients diagnosed with Alzheimer's disease seem to have an inherited form of the disease (apolipoprotein E4 genotype). Various abnormalities in brain neurotransmitters (chemicals which enable nerve cells to send signals to one another) have been found in Alzheimer's patients. For instance, studies have found decreases in the production of some neurotransmitters (e.g., acetylcholine), decreases in the brain's ability to use glucose (sugar) for fuel, and over-stimulation of some nerve cells by a substance called glutamate. This leads to death of nerve cells and consequent atrophy (shrinking) of the brain over time.

What is the course of Alzheimer's disease?

Alzheimer's disease generally progresses in a linear fashion over an average of seven years (as long as 20 years in some cases) from onset until death. A person progresses through several stages of deterioration, which roughly parallel the stages of infant and childhood development in reverse. The diagnosis of Alzheimer's disease is generally not made in a particular patient until several years after the actual onset of the disease due to its insidious onset.

When the disease first starts, the mild deficits in thinking that occur are often attributed to forgetfulness, depression, or aging. The Functional Assessment Staging (FAST) of Alzheimer's disease describes 16 stages, from Stage 1 (no difficulties experienced or observed) through Stage 7 (inability even to hold head up). The earlier stages are characterized by memory deficits, impaired judgment, decreased ability to function at work, and inability to perform complex tasks.

A person with moderate Alzheimer's disease will have difficulty with dressing independently and performing personal grooming and will need assistance with these activities. Language difficulties, such as progressive loss of vocabulary, also begin to emerge at these stages. As the person progresses to severe Alzheimer's disease, he or she becomes incontinent of urine and stool, fails to recognize loved ones, loses the ability to communicate meaningfully, and loses the ability to walk independently. In the final stages of the illness, the person develops dysphagia (difficulty swallowing or choking with swallowing), becomes bedbound and immobile, and loses even the ability to smile.

Is there a cure for Alzheimer's disease, or treatment that can reverse the damage?

There is currently no cure for Alzheimer's disease, and no treatments that effectively reverse the damage done to the brain. However, there are several treatments which try to normalize the brain's levels of neurotransmitter chemicals, and which have been shown to slow down, or even halt for a time, the relentless progression of the disease. These treatments are most likely to provide meaningful benefit to the patient with mild to moderate Alzheimer's disease, although some benefit can be seen even in severe Alzheimer's cases.

However, the AMA goes on to state: "Alzheimer's disease and other progressive dementias are life-altering and eventually fatal conditions for which curative therapy is not available. Thinking of dementia as a terminal illness from which people are dying over years instead of months allows one to focus explicitly and aggressively on a palliative care plan."

When a person with Alzheimer's disease enters the later stages, especially after the ability to walk independently is lost, the average life expectancy is about one year. Of those persons who also suffer from fever or infection, or those who have suffered a hip fracture, more than half will have died within six months.

Persons afflicted with the end stages of Alzheimer's disease and their families endure many sources of suffering. Alzheimer's patients in the end stages often have moderate to severe pain, profound weakness, muscle spasms and contractures, choking and difficulty swallowing, incontinence of urine and stool, inability to empty bladder or bowel, weight loss, severe agitation, and severe skin breakdown. The ability to reason and relate to loved ones is lost.

Their loved ones suffer chronic grief at the loss of the person they once knew, physical and emotional exhaustion from the burdens of caregiving, distress at witnessing the suffering of the patient, and depletion of income and personal resources. Family caregivers are at increased risk for significant illness and death. The costs to caregivers and society are staggering. The National Institute on Aging estimates that $100 billion/year in direct and indirect costs is spent on caring for patients with Alzheimer's disease.

Unfortunately, patients with end-stage Alzheimer's disease often receive burdensome medical interventions of questionable benefit and suffer from inadequately controlled symptoms. One study showed that, although end-stage Alzheimer's patients have four to five times the mortality rate after pneumonia or hip fracture of those without dementia, they receive the same amount of painful procedures, including daily needle sticks for blood work, placement of intravenous catheters, and painful injections of medicines.

In this same study, Alzheimer's patients were more likely to undergo placement of catheters into the bladder and placement of feeding tubes through the nose or surgically through the abdomen than patients who were not demented. In spite of the fact that tube feeding has not been shown to prevent aspiration (contents of mouth or stomach go into the lung), prolong survival, reduce infections, improve functioning, or increase patient comfort, persons with advanced Alzheimer's disease undergo placement of feeding tubes at alarming rates.

Tube-fed patients with Alzheimer's disease and other dementing illnesses typically die within a year, have increased lung infections, and show increased agitation requiring more use of physical restraints and sedation, which in turn results in more instances of painful skin breakdown.

Hospice and palliative care can help address these issues for patients and their families. Hospice care typically addresses directly what studies have shown patients with serious illnesses want, pain and symptom control:

When your loved one can no longer care for him or herself and has lost the ability to walk independently, especially if you are feeling stressed from caregiving, ask hospice to evaluate your loved one for admission. Particularly when your loved one has begun having choking episodes, is losing weight, or has had fever and infections; it is likely time to ask hospice for help.

The majority of hospice programs are able to serve patients in a nursing or assisted living facility. The hospice will need to have a contractual relationship with the facility. Ask the facility where your loved one is living which hospices have contracts with them. Then do your homework in choosing the best fit for your loved one and yourself.

A general rule of thumb for determining when these and other dementing illnesses or neurodegenerative diseases are appropriate for hospice referral is the following:

When the person becomes severely impaired in function (e.g., can't walk, can't feed self), becomes incontinent, has choking episodes or difficulty with breathing, or has significant weight loss (>10% body weight in 6 months), and the patient's and family's goals for care are palliative (comfort-focused) and not life-prolonging, hospice consultation is warranted.

In summary, end-stage Alzheimer's disease can be thought of as "brain failure," analogous to "kidney failure" or "liver failure." Failure of a vital organ without possibility of recovery or replacement of the organ function leads to death. The brain is the most vital organ, so conditions that cause "brain failure" are indeed terminal illnesses. Persons suffering these illnesses deserve, and indeed are entitled to, the option of hospice and palliative care. Hospices have long accepted into their programs persons with dementing illnesses diseases, and the Medicare Hospice Benefit and most private health insurance plans cover hospice services for these terminal conditions.