Alzheimer's disease (AD), also known as Alzheimer disease, Senile Dementia of the Alzheimer Type (SDAT) or simply Alzheimer's, is the most common form of dementia, a group of disorders that impairs mental functioning. (Dementia literally means loss of mentation, or thinking.) At the moment, Alzheimer's is progressive and irreversible. Abnormal changes in the brain worsen over time, eventually interfering with many aspects of brain function. Memory loss is one of the earliest symptoms, along with a gradual decline of other intellectual and thinking abilities, called cognitive functions, and changes in personality or behavior.
Alzheimer's advances in stages, progressing from mild forgetfulness and cognitive impairment to widespread loss of mental abilities. In advanced Alzheimer's, people become dependent on others for every aspect of their care. The time course of the disease varies by individual, ranging from five to 20 years. The most common cause of death is infection.
This incurable, degenerative, and terminal disease was first described by German psychiatrist and neuropathologist Alois Alzheimer in 1906 and was named after him. Generally it is diagnosed in people over 65 years of age. An estimated 26.6 million people worldwide had Alzheimer's in 2006.
CAUSES
Scientists have made significant progress in understanding the possible causes of Alzheimer's disease, but many questions remain. It is likely that many factors, both inherited and environmental, interact in complex, poorly understood ways to cause the disease.
In addition to investigating what might trigger Alzheimer's in some people, scientists have identified a number of brain changes that are associated with Alzheimer's. These include the characteristic plaques and tangles around and inside nerve cells that were first described by Alois Alzheimer in 1906.
In addition to age and family history, risk factors for AD may include:
- Longstanding high blood pressure
- History of head trauma
- High levels of homocysteine (a body chemical that contributes to chronic illnesses such as heart disease, depression, and possibly AD)
- Female gender -- because women usually live longer than men, they are more likely to develop AD
SYMPTOMS
In the early stages, the symptoms of AD may be subtle and resemble signs that people mistakenly attribute to "natural aging." Symptoms often include:
- Repeating statements
- Misplacing items
- Having trouble finding names for familiar objects
- Getting lost on familiar routes
- Personality changes
- Losing interest in things previously enjoyed
- Difficulty performing tasks that take some thought, but used to come easily, like balancing a checkbook, playing complex games (such as bridge), and learning new information or routines
In a more advanced stage, symptoms are more obvious:
- Forgetting details about current events
- Forgetting events in your own life history, losing awareness of who you are
- Problems choosing proper clothing
- Hallucinations, arguments, striking out, and violent behavior
- Delusions, depression, agitation
- Difficulty performing basic tasks like preparing meals and driving
At end stages of AD, a person can no longer survive without assistance. Most people in this stage no longer:
- Understand language
- Recognize family members
- Perform basic activities of daily living such as eating, dressing, and bathing
TREATMENT
There is no cure for Alzheimer's disease; available treatments offer relatively small symptomatic benefit but remain palliative in nature. Current treatments can be divided into pharmaceutical, psychosocial and caregiving.
Pharmaceutical
Four medications are currently approved by regulatory agencies such as the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMEA) to treat the cognitive manifestations of AD: three are acetylcholinesterase inhibitors and the other is memantine, an NMDA receptor antagonist. No drug has an indication for delaying or halting the progression of the disease.
Psychosocial intervention
Psychosocial interventions are used as an adjunct to pharmaceutical treatment and can be classified within behaviour-, emotion-, cognition- or stimulation-oriented approaches. Research on efficacy is unavailable and rarely specific to AD, focusing instead on dementia in general.
Behavioural interventions attempt to identify and reduce the antecedents and consequences of problem behaviours. This approach has not shown success in improving overall functioning, but can help to reduce some specific problem behaviours, such as incontinence. There is a lack of high quality data on the effectiveness of these techniques in other behaviour problems such as wandering.
Emotion-oriented interventions include reminiscence therapy, validation therapy, supportive psychotherapy, sensory integration, also called snoezelen, and simulated presence therapy. Supportive psychotherapy has received little or no formal scientific study, but some clinicians find it useful in helping mildly impaired patients adjust to their illness. Reminiscence therapy (RT) involves the discussion of past experiences individually or in group, many times with the aid of photographs, household items, music and sound recordings, or other familiar items from the past. Although there are few quality studies on the effectiveness of RT, it may be beneficial for cognition and mood. Simulated presence therapy (SPT) is based on attachment theories and involves playing a recording with voices of the closest relatives of the person with Alzheimer's disease. There is partial evidence indicating that SPT may reduce challenging behaviours. Finally, validation therapy is based on acceptance of the reality and personal truth of another's experience, while sensory integration is based on exercises aimed to stimulate senses. There is little evidence to support the usefulness of these therapies.
The aim of cognition-oriented treatments, which include reality orientation and cognitive retraining, is the reduction of cognitive deficits. Reality orientation consists in the presentation of information about time, place or person in order to ease the understanding of the person about its surroundings and his or her place in them. On the other hand cognitive retraining tries to improve impaired capacities by exercitation of mental abilities. Both have shown some efficacy improving cognitive capacities, although in some studies these effects were transient and negative effects, such as frustration, have also been reported.
Stimulation-oriented treatments include art, music and pet therapies, exercise, and any other kind of recreational activities. Stimulation has modest support for improving behaviour, mood, and, to a lesser extent, function. Nevertheless, as important as these effects are, the main support for the use of stimulation therapies is the change in the person's routine.
Caregiving
Since Alzheimer's has no cure and it gradually renders people incapable of tending for their own needs, caregiving essentially is the treatment and must be carefully managed over the course of the disease.
During the early and moderate stages, modifications to the living environment and lifestyle can increase patient safety and reduce caretaker burden. Examples of such modifications are the adherence to simplified routines, the placing of safety locks, the labelling of household items to cue the person with the disease or the use of modified daily life objects. The patient may also become incapable of feeding themselves, so they require food in smaller pieces or pureed. When swallowing difficulties arise, the use of feeding tubes may be required. In such cases, the medical efficacy and ethics of continuing feeding is an important consideration of the caregivers and family members. The use of physical restraints is rarely indicated in any stage of the disease, although there are situations when they are necessary to prevent harm to the person with AD or their caregivers.
As the disease progresses, different medical issues can appear, such as oral and dental disease, pressure ulcers, malnutrition, hygiene problems, or respiratory, skin, or eye infections. Careful management can prevent them, while professional treatment is needed when they do arise. During the final stages of the disease, treatment is centred on relieving discomfort until death.
