Alzheimer’s Disease: When Memory Fades

At first it’s just the front door key that disappears and later turns up in unusual places. Then you stand in the supermarket and wonder about the meaning of the numerous colorful things. Later, your own apartment is suddenly unknown territory. And in the end, you don’t even recognize the partner with whom you spent a lifetime together. Alzheimer’s disease is the name of the relentless opponent that is increasingly entering the ring in industrialized countries and always wins in the end.

Alzheimer’s disease: a form of dementia

The disease, named after the neurologist Alois Alzheimer (1864 – 1915), has been known for about 100 years. It is a form of dementia, i.e. a decline in mental capacity, and usually occurs in old age. In view of rising life expectancy, the risk of developing the disease is increasing – in Germany, up to 1.6 million people are currently affected by dementia, the majority of whom suffer from Alzheimer’s disease. It is estimated that around 5% of those over sixty and 20% of those over eighty suffer from Alzheimer’s disease. It is second only to strokes as the most common serious brain dysfunction in old age. Rare, hereditary forms, however, can affect people over the age of thirty.

How does this disease develop?

Scientists still do not know exactly all the mechanisms that lead to the disease. They do know, however, that protein fragments called amyloids are deposited in the brain decades before the onset. These appear under the microscope either as typical small fibers (fibrils) or spherical structures (plaques). The deposits seem to prevent the exchange of information between the nerve cells, which die after a while. It is also known that in the rare cases where younger people are affected, the formation of the amyloids in the brain starts very early due to a genetic defect. Certain gene variants increase the risk and can be determined with a blood test. However, the researchers do not yet know which triggers in detail set the processes in motion and what exactly is the cause and what is the consequence.

What are the symptoms of the disease?

Almost always, the disease begins with memory weakness, initially mainly disturbances of short-term memory and concentration, later also speech disorders. Mental performance decreases more and more, accompanied by fatigue and loss of judgment. Those affected often develop depression during this phase. Typical in the further course are behavioral changes and personality disorders up to delusions. Patients are confused, anxious, restless or aggressive. They drag objects around, everyday activities such as shopping or dressing become increasingly difficult to manage, and people and objects are no longer recognized. The affected persons increasingly live in the past. In the end, they are dependent on extensive assistance, no longer have control over their bodily functions, can no longer speak and are often bedridden.

How is the diagnosis made?

With ultimate certainty, the disease can be determined only after the patient’s death by the typical deposits in the brain. In practice, it is nevertheless important to diagnose the disease as early as possible, especially to positively influence its course. The focus is on the typical medical history, usually described by the relatives. Based on this, various examinations are performed to rule out other physical or psychiatric illnesses as the cause of the dementia. These include blood tests, the ECG to assess heart function and a test to check lung function. In some cases, imaging techniques such as magnetic resonance imaging and computed tomography may also be indicated. Newer procedures such as single-photon emission tomography (SPECT) and positron emission tomography (PET) are more informative, but decidedly expensive. Mental performance is tested by the physician using various neuropsychological tests (e.g., Mini-Mental Status Test). For example, the patient has to answer questions and – e.g. the dial of a clock – draw, calculate, follow simple instructions and remember words. These tests are also used to assess the person’s condition as he or she progresses and to see if therapy is working.

What treatment is available?

There is currently no cure for Alzheimer’s disease.However, some therapies are known to significantly delay the disease process. The aim is to train the affected person’s everyday competence and to maintain it for as long as possible. This is achieved primarily with behavioral, memory and self-preservation training, as well as physical and occupational therapy. Familiar surroundings and a regular, consistent daily routine are important for patients, and the demands placed on them must be tailored to their abilities. In addition, psychological support is helpful, especially for relatives, who face a physically and emotionally exhausting responsibility and activity in caring for the affected person.

Medication in Alzheimer’s disease

Today, cholinesterase inhibitors and memantine are available to treat Alzheimer’s dementia. Cholinesterase inhibitors improve brain performance. However, their effect varies greatly from person to person and usually lasts no longer than twelve months. Memantine, in addition to improving cognitive abilities, also leads to an improvement in daily living skills. In a recent study, memantine was also shown to improve dementia-associated behavioral disorders such as mood swings and agitation. Herbal preparations, especially those containing extracts from the ginkgo tree, are also thought to improve memory performance. Several scientific studies show a positive effect, at least with high doses. Others, however, rate the effect no higher than that of placebos.

What’s the prognosis?

The course of the disease varies greatly from individual to individual and cannot be accurately predicted. However, in all cases, the disease progresses steadily. From the time of diagnosis, those affected live an average of about 8 years – causes of death are usually physical illness as a result of bedriddenness and mental and physical deterioration.

Present and future

Experts warn of a new “widespread disease” that will place an immense burden on the health and care system in the future. Researchers agree that the greatest opportunity lies in early detection of the disease, long before symptoms become apparent. They believe that in the future this could be achieved with the help of a blood test or by means of imaging techniques. According to current knowledge and based on American studies, a healthy diet rich in vitamins, physical activity and mental activity are extremely important for delaying the onset of the disease. An “Alzheimer’s vaccine” is currently at the trial stage, which is intended to prevent the protein particles from being deposited. Initial results are encouraging. However, experts anticipate a development time of 10 to 20 years before it is ready for practical use.

Development of Alzheimer’s preventable?

In April 2007, scientists at Freie Universität Berlin made a significant advance in the study of Alzheimer’s disease. A research group has discovered how to prevent the formation of the disease-causing amyloid beta peptide. Until this point, the circumstances under which this toxic peptide forms, which leads to the degeneration of nerve cells and thus to Alzheimer’s disease, were unknown. Laboratory experiments showed that the formation of the harmful substance can be prevented by altering the degradation of the precursor protein to produce shorter forms that are no longer toxic. Although the peptide is also formed in this way, it is considerably less.