Alzheimer’s disease is a type of progressive deterioration of
the structure and function of the brain. In the "preclinical" stage, a person
may function appropriately in his or her home and work environment, and
abnormalities in cognition may be apparent only on detailed neuropsychologic
testing. Eventually, cognitive deficits become noticeable.
A person with Alzheimer’s disease early on has difficulty with
short-term memory, making lists, keeping track of complicated appointments or
social schedules, organizing a vacation trip, navigating directions using a map,
or coordinating a multi-course holiday family dinner. Later in the disease,
there are often problems with long-term memory, mood, apathy, agitation, and
abnormal motor activity (e.g., pacing). Affected people have trouble using
appliances—first, complex ones, such as the car or dishwasher; later, the
telephone; and eventually even table utensils.
Not every memory problem becomes dementia, and not every cause
of dementia is Alzheimer’s disease. Dementia means that there is a loss of
memory and at least one other aspect of cognition, such as abstract thinking,
personality, or executive (organizational) ability, and that the loss interferes
with function. Dementia cannot be diagnosed when a person becomes suddenly ill,
such as with a fever, infection, metabolic derangement, etc.
Alzheimer’s disease is the most common cause of dementia.
However, stroke, alcohol, Parkinson’s disease, and other medical conditions can
cause dementia as well.
Alzheimer’s disease has both a genetic and an environmental
component. The genetic component is very strong in those diagnosed with
Alzheimer’s disease in their 40s or early 50s. However, these represent a small
fraction of the Alzheimer’s disease population. Most people with Alzheimer’s
disease develop symptoms in their 70s and 80s; and the genetic component is much
weaker at this age. Only 50 percent of identical twins of older Alzheimer’s
patients are diagnosed with Alzheimer’s disease.
Health and environmental factors, such as mental and physical
activity, and treatment of medical conditions such as hypertension and diabetes,
play a strong role in postponing symptoms of Alzheimer’s disease. Genetic
testing for Alzheimer’s disease occurring after age 60 is not generally
recommended.
Stages of Alzheimer’s disease
Very mild: This stage is usually not diagnosed because
people in this stage are functioning at a high level. Occasionally, they may
report having more problems than usual with short-term memory, or remembering
names or where they placed their belongings. However, they balance their
checkbook, keep appointments, and continue to drive.
People compensate by giving themselves more time to adapt and
perhaps by writing reminder notes. Some people may become anxious about their
memory deficits. There is no specific treatment except for lifestyle.
Mild: In this stage, cognitive deficits are noticeable
in demanding situations. The key to diagnosing mild dementia is that function at
home or work is impaired, although slightly. Affected people begin to require
assistance in complicated tasks such as planning a party or handling finances.
They may exhibit problems remembering life events (hospitalizations, medical
conditions, educational/job milestones), have trouble concentrating, and may
have trouble traveling, particularly to unfamiliar places.
Most people in the mild stage have no difficulty with familiar
faces, are not disoriented with respect to time, and can usually travel to
familiar places. However, people with Alzheimer’s tend to back away from dealing
with difficult or challenging situations. Their mood may be a bit "flat." Most
are not aware of the extent of their deficits. They may say they have the same
memory problems everyone else their age has, but they really don’t appreciate
the extent of their loss.
Most persons with mild Alzheimer’s disease may still be driving.
They should be encouraged to be evaluated by a driver rehabilitation specialist
to assess their driving risks and to participate in therapy to improve their
driving ability and lower their risks. Medicare covers an Occupational Therapy
evaluation for certain diagnoses, such as stroke or lack of coordination. If
Medicare does not cover it for you in your region of the country, consider an
evaluation by a private driving school from an instructor who is certified in
driver rehabilitation.
Moderate: People in the moderate stage of Alzheimer’s
cannot get by without assistance. They need help choosing proper attire and may
need prompting to put the clothes on in the proper order. Kitchen safety (e.g.,
fire from an unattended pot on the stove) may be an issue, and appliances such
as the stove may need to be disabled. If still driving, they should be persuaded
to "retire" from driving. They also may not be able to manage their medications
or finances safely.
While there is some disorientation with time, such as
remembering that the Cold War followed World War II, people with moderate
dementia can still remember major information about themselves, their families,
and others. There may be delusional behavior, depression, apathy, or anxiety as
the disease progresses.
Moderately severe: As memory loss progresses, a person
may not consistently recognize his or her children or spouse, or may confuse
them with other family members. Functionally, the person loses skills in
dressing, bathing, and then toileting. Urinary incontinence and, later, fecal
incontinence occur. Sleep is often disturbed.
Severe: The person’s speech ability becomes limited to
about half dozen words, and eventually, intelligible vocabulary decreases to a
single word. He or she has lost or will lose the ability to walk, sit up, smile,
and eventually hold up his or her head. The brain now appears unable to tell the
body what to do. The person may sit on the toilet, having forgotten how to move
his or her bowels, or may be incontinent prior to reaching the toilet.
A person with severe dementia will hold food in his or her mouth, having forgotten how to swallow. Weight loss, aspiration, and bedsores may occur as the disease progresses. Hospice care may be appropriate at this time for comfort and palliation.
Treatment of Alzheimer’s disease
Lifestyle: These recommendations are appropriate at all
stages of disease, but need to be tailored to the individual’s preferences and
abilities. In general, healthy lifestyle changes that protect the body from
strokes and heart attacks tend to protect the brain from cognitive decline.
Older adults who exercise, maintain their normal body weight, avoid head trauma,
have no more than one standard alcoholic beverage daily, and stay socially
engaged maintain their cognitive abilities best.
Adults in early stages could attend courses at a local community
college, take classes at a senior center, and/or participate in library book
clubs. Those with moderate or severe disease may benefit from organized
activities in an adult daycare setting. The Office of Aging and the Alzheimer’s
Association in your community can provide information on local sites. Also,
treatment of hypertension is important in protecting the brain against cognitive
decline, as is prevention and treatment of diabetes with exercise and
medications.
Cholinesterase inhibitors: These medications are
approved by the FDA to treat the symptoms of mild to moderate Alzheimer’s
disease (AD). Cholinesterase inhibitors include:
- Tacrine (also called Cognex®, which is
still on the market but not usually prescribed because of liver side effects)
- Donepezil (Aricept®) (FDA-approved for
all stages of AD
- Galantamine (Razadyne®)
- Rivastigmine (Exelon®)
Cholinesterase inhibitors block the action of
acetylcholinesterase, the enzyme responsible for the destruction of
acetylcholine. Acetylcholine is one of several neurotransmitters in the brain
(chemicals that nerve cells use to communicate with one another).
Reduced levels of acetylcholine in the brain are believed to be
responsible for some of the symptoms of Alzheimer’s disease. By blocking the
enzyme that destroys acetylcholine, these medications increase the concentration
of acetylcholine in the brain. This increase is believed to be responsible for
the improvement in memory and cognition seen with these medications.
The improvement is modest and lasts six to12 months. After that
period of time, decline in memory resumes. However, researchers think that
people on a cholinesterase inhibitor may still experience improvements in
function and behavior when maintained on these medications for a prolonged period of time.
These improvements may help reduce caregiver burden, delay nursing home placement, and improve neuropsychiatric problems (such as apathy and agitation).
Memantine (Namenda®):
Memantine is approved by the FDA for treatment of moderate to severe Alzheimer’s
disease. It blocks the neurotransmitter glutamate from activating NMDA receptors
on nerve cells, keeping the cells healthier. This mechanism is different than
that of the cholinesterase inhibitors.
Patients with moderate to severe Alzheimer’s who were treated
with memantine performed better on scales measuring the common activities of
daily living such as eating, walking, toileting, bathing, and dressing compared
with patients taking placebo. Patient with lower functioning may benefit the most.
Memantine appears to be safe and effective alone or when used
together with a cholinesterase inhibitor. It may also help with neuropsychiatric
symptoms. However, like with the cholinesterase inhibitors, the effect on
cognition and abilities is modest and declines after about six months. Research
is ongoing to determine long-term benefits.
Miscellaneous:
- The evidence supporting a benefit for the herbal product gingko biloba is weak.
- Persons with Vitamin D deficiency may have more cognitive
deficits than persons with normal levels of Vitamin D. There is no evidence
that treating Vitamin D improves cognition. However, treating Vitamin D
deficiency has other benefits, such as reducing the risks of falls and hip
fractures. Older adults should take 1,000 units of Vitamin D (cholecalciferol)
daily.
- Vitamin E in high doses for older adults with moderate AD may delay
nursing home entry but is associated with an increased risk of death in
epidemiological studies.
- Selegiline may have a benefit equivalent to Vitamin E but has more
side effects.
- Estrogen does not improve cognition when administered to a woman
with Alzheimer’s disease.
- Studies of nonsteroidal anti-inflammatory medications such as
Naprosyn® and Celebrex®
in persons with cognitive impairment demonstrate no benefit in preventing
AD, and may cause kidney and stomach problems in older adults.
- Interventional studies with cholesterol-lowering medications, psychotropic stimulants, certain diabetes medications, antioxidants, and folic acid supplements are ongoing but at this time show no benefit.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 8/12/2008…#11825
