Alzheimer: Brief overview
- What is Alzheimer’s disease? Most common form of dementia, affects about 20 percent of those over 80. Differentiate between presentile (< 65 years) and senile Alzheimer's (> 65 years).
- Causes: Death of nerve cells in the brain due to protein deposits.
- Risk factors: Age, high blood pressure, elevated cholesterol, vascular calcification, diabetes mellitus, depression, smoking, few social contacts, genetic factors
- Early symptoms: fading short-term memory, disorientation, word-finding disorders, altered personality, weakened immune system
- Diagnosis: by combination of several tests, doctor’s consultation, brain scans by PET-CT or MRI, cerebrospinal fluid diagnostics
- Treatment: no cure, symptomatic therapy with anti-dementia drugs, neuroleptics, antidepressants; non-drug therapy (e.g. cognitive training, behavioral therapy)
- Prevention: healthy diet, regular exercise, memory challenge, many social contacts
Alzheimer’s disease: causes and risk factors
The Meynert basal nucleus is particularly early to be affected by cell death: The nerve cells of this deeper brain structure produce the nerve messenger acetylcholine. Cell death in the Meynert basal nucleus thus triggers a significant deficiency of acetylcholine. As a result, information processing is disturbed: those affected can hardly remember events that occurred in the short past. Their short-term memory thus dwindles.
Protein deposits kill nerve cells
Two different types of protein deposits are found in the affected brain regions, which kill the nerve cells. Why these form is unclear.
Beta-amyloid: Hard, insoluble plaques of beta-amyloid form between nerve cells and in some blood vessels. These are fragments of a larger protein whose function is still unknown.
Tau protein: In addition, in Alzheimer’s patients, abnormal tau fibrils – insoluble, twisted fibers made of the so-called tau protein – form in the nerve cells of the brain. They disrupt the stabilization and transport processes in the brain cells, causing them to die.
Alzheimer’s disease: risk factors
The main risk factor for Alzheimer’s is age: only two percent of people under the age of 65 develop this form of dementia. In the 80 to 90 age group, on the other hand, at least one in five is affected, and more than one third of those over 90 suffer from Alzheimer’s disease.
However, age alone does not cause Alzheimer’s. Rather, experts assume that other risk factors must be present before the onset of the disease occurs.
Overall, the following factors can promote Alzheimer’s disease:
- age
- genetic causes
- high blood pressure
- elevated cholesterol level
- increased homocysteine level in the blood
- vascular calcification (arteriosclerosis)
- oxidative stress, caused by aggressive oxygen compounds that play a role in the formation of protein deposits in the brain
There are other factors that may increase the risk of Alzheimer’s but need to be researched in more detail. These include inflammation in the body that persists over time: They could damage brain cells and promote the formation of protein deposits, researchers believe.
Other possible Alzheimer’s risk factors include low general education levels, head injuries, brain infection from viruses, and an increase in autoimmune antibodies in older people.
Aluminum & Alzheimer’s
Autopsies have shown that the brains of deceased Alzheimer’s patients have elevated levels of aluminum. However, this does not necessarily mean that aluminum causes Alzheimer’s. Animal experiments speak against it: When mice are given aluminum, they still do not develop Alzheimer’s.
Is Alzheimer’s hereditary?
Only about one percent of all Alzheimer’s patients have the familial form of the disease: Here, Alzheimer’s is triggered by various gene defects that are passed on. The amyloid precursor protein gene and the presenilin-1 and presenilin-2 genes are affected by the mutation. Those who carry these mutations always develop Alzheimer’s, and they do so between the ages of 30 and 60.
The vast majority of Alzheimer’s patients, however, exhibit the sporadic form of the disease, which generally does not break out until after the age of 65. It is true that the sporadic form of Alzheimer’s also appears to have a genetic component: This involves, for example, changes in the gene for the protein apo-lipoprotein E, which is responsible for cholesterol transport in the blood. However, changes in this gene do not lead to the definite onset of the disease, but only increase the risk of it.
Alzheimer’s disease: symptoms
As Alzheimer’s disease progresses, symptoms intensify and new symptoms are added. Therefore, below you will find the symptoms arranged according to the three stages into which the course of the disease is divided: Early stage, Middle stage and Late stage:
Early stage Alzheimer’s symptoms.
Early Alzheimer’s symptoms are minor memory lapses that affect short-term memory: For example, patients may not be able to retrieve recently discarded items or remember the content of a conversation. They may also “lose the thread” in the middle of a conversation. This increasing forgetfulness and absentmindedness can confuse and frighten those affected. Some also react to it with aggressiveness, defensiveness, depression or withdrawal.
Other early signs of Alzheimer’s may include mild orientation problems, lack of drive, and slowed thinking and speech.
In mild Alzheimer’s dementia, everyday life can usually still be managed without any problems. Only with more complicated things do those affected often need help, for example in managing their bank account or using public transport.
Alzheimer’s symptoms in the middle stage of the disease
Alzheimer’s symptoms in the middle stages of the disease are aggravated memory disorders: Patients are less and less able to remember events that occurred in the short past, and long-term memories (of their own wedding, for example) gradually fade as well. Familiar faces become increasingly difficult to recognize.
Difficulties in orienting themselves in time and space also increase. Patients search for their long-dead parents, for example, or can no longer find their way home from the familiar supermarket.
Communication with patients also becomes increasingly difficult: those affected are often no longer able to form complete sentences. They need clear prompts, which often have to be repeated before they sit down at the dining table, for example.
Other possible Alzheimer’s symptoms in the middle stages of the disease are an increasing urge to move and severe restlessness. For example, patients restlessly walk back and forth or continually ask the same question. Delusional fears or beliefs (such as being robbed) may also occur.
Late-stage Alzheimer’s symptoms
In the late stages of the disease, patients are in need of total care. Many need a wheelchair or are bedridden. They no longer recognize family members and other close people. Speech is now limited to a few words. Finally, patients can no longer control their bladder and bowels (urinary and fecal incontinence).
Atypical Alzheimer’s course
In about one-third of patients who develop the disease at a younger age (a small group overall), the course of Alzheimer’s is atypical:
- Some patients develop behavioral changes toward antisocial and flamboyant behavior similar to those seen in frontotemporal dementia.
- In a second group of patients, word-finding difficulties and slowed speech are the main symptoms.
- In a third form of the disease, visual problems occur.
Alzheimer’s disease: examinations and diagnosis
Taking your medical history
If Alzheimer’s disease is suspected, the doctor will first talk to you in detail to take your medical history (anamnesis). He will ask you about your symptoms and any previous illnesses. The doctor will also ask about any medications you are taking. This is because some medications can impair brain performance. During the interview, the doctor will also look at how well you can concentrate.
Ideally, someone close to you should accompany you to this consultation. Because in the course of Alzheimer’s disease, the nature of the person affected can also change. Phases of aggression, suspicion, depression, fears and hallucinations can occur. Such changes are sometimes noticed more quickly by others than by the person affected.
Physical examination
After the interview, the doctor will examine you routinely. For example, he will measure blood pressure and check muscle reflexes and pupillary reflex.
Dementia tests
In addition to the aforementioned brief tests, more detailed neuropsychological examinations are often performed.
Apparative examinations
If there are clear signs of dementia, the patient’s brain is usually examined using positron emission computed tomography (PET/CT) or magnetic resonance imaging (MRI, also called magnetic resonance imaging). This can be used to find out if the brain matter has decreased. This would confirm the suspicion of dementia.
Imaging studies of the skull are also used to determine any other conditions that may be responsible for dementia symptoms, such as a brain tumor.
Laboratory tests
Blood and urine samples from the patient can also be used to determine if a disease other than Alzheimer’s is causing the dementia. This could be a thyroid disease or a deficiency of certain vitamins, for example.
If the doctor suspects that the patient is suffering from the rare hereditary form of Alzheimer’s disease, a genetic test can provide certainty.
Alzheimer’s disease: treatment
There is only symptomatic treatment for Alzheimer’s disease – a cure is not yet possible. However, the right therapy can help patients to manage their daily lives independently for as long as possible. In addition, Alzheimer’s medications and non-drug therapy measures alleviate patients’ symptoms and thus promote quality of life.
Anti-dementia drugs
Various groups of active ingredients are used in drug therapy for Alzheimer’s disease:
So-called cholinesterase inhibitors (such as donepezil or rivastigmine) block an enzyme in the brain that breaks down the nerve messenger acetylcholine. This messenger is important for communication between nerve cells, concentration and orientation.
In moderate to severe Alzheimer’s dementia, the active ingredient memantine is often given. Like cholinesterase inhibitors, it can delay the decline in mental performance in some patients. More precisely, memantine prevents an excess of the nerve messenger glutamate from damaging the brain cells. Experts suspect that in Alzheimer’s patients, excess glutamate contributes to the death of nerve cells.
Extracts from ginkgo leaves (Ginkgo biloba) are thought to improve blood flow to the brain and protect nerve cells. Patients with mild to moderate Alzheimer’s dementia may thus be able to cope better with everyday activities again. In high doses, ginkgo also seems to improve memory performance and relieve psychological symptoms, as some studies show.
Other drugs for Alzheimer’s disease
However, these agents can have serious side effects. These include an increased risk of stroke and increased mortality. The use of neuroleptics is therefore closely monitored. In addition, these drugs should be taken in as low a dose as possible and not on a long-term basis.
Many Alzheimer’s patients also suffer from depression. Antidepressants such as citalopram, paroxetine or sertraline help against this.
In addition, other existing underlying and concomitant diseases such as elevated blood lipid levels, diabetes or high blood pressure must be treated with medication.
Non-drug treatment
Non-drug therapy measures are very important in Alzheimer’s disease. They can help to delay the loss of mental abilities and maintain independence in everyday life for as long as possible.
Cognitive training can be particularly useful for mild to moderate Alzheimer’s dementia: it can train the ability to learn and think. For example, simple word games, guessing terms or adding rhymes or familiar proverbs are suitable.
As part of behavioral therapy, a psychologist or psychotherapist helps patients to cope better with psychological complaints such as anger, aggression, anxiety and depression.
Autobiographical work is a good way of keeping memories of earlier periods of life alive: relatives or caregivers specifically ask Alzheimer’s patients about their earlier lives. Photos, books or personal objects can help to evoke memories.
Occupational therapy can be used to maintain and promote everyday skills. Alzheimer’s patients practice dressing, combing, cooking and hanging up laundry, for example.
Alzheimer’s disease: course and prognosis
Alzheimer’s disease leads to death after an average of eight to ten years. Sometimes the disease progresses much faster, sometimes slower – the time span ranges from three to twenty years, according to current knowledge. In general, the later in life the disease appears, the shorter the Alzheimer’s course.
Preventing Alzheimer’s
As with many diseases, the likelihood of developing Alzheimer’s can be reduced by adopting a healthy lifestyle. Factors such as elevated cholesterol levels, obesity, high blood pressure and smoking can actually promote Alzheimer’s and other dementias. Such risk factors should therefore be avoided or treated if possible.
In addition, a Mediterranean diet with plenty of fruit, vegetables, fish, olive oil and wholemeal bread seems to prevent Alzheimer’s and other forms of dementia.
The risk of Alzheimer’s and other forms of dementia also decreases if you are mentally active throughout your life, both at work and in your leisure time. For example, cultural activities, puzzles and creative hobbies can stimulate the brain and preserve memory.
As studies have shown, a lively social life can also prevent dementia diseases such as Alzheimer’s: the more you socialize and get involved in communities, the greater the likelihood that you will still be mentally fit at an older age.
