Alzheimer’s disease: causes, symptoms and therapy

Index

  • What is Alzheimer’s disease
  • Possible causes of Alzheimer’s
  • Alzheimer’s disease diagnosis
  • Symptoms of Alzheimer’s
  • How Alzheimer’s disease evolves
  • Alzheimer’s disease treatment
  • Alzheimer’s rehabilitation

Questions and answers

What is Alzheimer’s disease

Alzheimer’s disease is the most common form of senile dementia , affecting about 5% of people over 60 today . Although most sufferers are over 80, there are cases of early Alzheimer’s , even in their 40s or 50s. Like all dementias, it is characterized by a progressive loss of memory associated with a cognitive disorder: loss of language, executive skills and critical or abstract thinking.

It is defined as a brain disease characterized by progressive and irreversible dementia that occurs in adulthood or senile age. In essence, a mechanism is activated that destroys the cells of the brain, causing deteriorationcurrently irreversible of cognitive functions .
From a morphological point of view, in Alzheimer’s disease the brain is reduced in weight and volume due to a widespread atrophy of the brain tissue. The characteristic anatomo-pathological changes are:

  • “ Senile plaques ”, amyloid aggregates in the extra-cellular space;
  • “ Neurofibrillary degeneration ”, protein deposits inside the nerve cell;
  • “ Amyloid angiopathy ”, amyloid- induced vascular damage.

Alzheimer’s is not a single disease, but we don’t know a great deal from a morphological point of view . An article published in Nature in 2017 identified a variability in the characteristics of the beta-amyloid protein clusters , which results in different types of disease: typical form , posterior cortical atrophy and rapid progressive .

See the centers that have claimed to be specialized in Alzheimer’s:
Alzheimer’s specialized centers

Possible causes of Alzheimer’s

Only in 1% of patients the disease has a genetic origin and is therefore hereditary , in the sense that it is possible (certainly not) that it appears between close generations in close relatives. Generally in these cases, Alzheimer’s is due to an autosomal dominant genetic mutation present from birth and the children of the carrier present, regardless of sex, a 50% risk of inheriting the disease.

Until now, scientific research has been able to identify some of the genes in which mutations may be present (Presenilin1, Presenilin2 and the Precursor of the Beta-Amyloid Protein APP). But it should be noted that not all mutations are known at the moment.
In the remaining 99% of casesthe onset of the disease is sporadic . The triggering cause is not known, but the correlation between the disease and the alteration of the metabolism of the precursor protein of beta amyloid (called APP) is being studied, which leads to the formation of beta amyloid, a neurotoxic substance that accumulates in the brain progressively to neuronal death. As there is no known trigger, there are no targeted prevention methods .

However, clinical studies show that several factors, in addition to genetic ones, could play an important role in the development and course of the disease, such as:

  • Healthy and balanced diet ;
  • Physical activity ;
  • Social commitment .

These factors play a fundamental role in keeping people healthy despite their age and for this reason could be implicated in the development of Alzheimer’s.

Alzheimer’s disease diagnosis

Total certainty of the presence of the disease can only be done with a brain biopsy to identify amyloid plaques in brain tissue, i.e. with an autopsy. The diagnoses in life are therefore only of:

  • Alzheimer’s disease possible . Diagnosis is based on the observation of clinical symptoms and on the deterioration of two or more cognitive functions (e.g. memory, language or thinking) in the presence of a second disease which, although not acting as a cause, still makes the diagnosis of Alzheimer’s disease more doubtful;
  • Probable Alzheimer’s disease . The diagnosis is always based on the observation of clinical symptoms and on the deterioration of two or more cognitive functions but there is no presence of a second disease.

There is therefore no specific test to diagnose the disease, but other pathologies are excluded. The first thing that is done is a visit where the doctor asks the patient and family some questions, for example about memory difficulties or managing their needs. The patient may undergo a neuropsychological examination , and a test called the Mini-Mental State Examination (MMSE) is often used , which consists of a series of specific questions (such as the clock test ) and simple operations to be performed by the patient. patient. Laboratory tests
are then proposed to rule out other diseases and instrumental tests such asMagnetic resonance and CT scan (computerized axial tomography) which allows to measure the thickness of a part of the brain, which in Alzheimer’s patients is thinned. It is then possible to subject the patient to SPECT (single photon emission computed tomography) which measures the blood flow in the brain and PET (positron emission tomography).

Symptoms of Alzheimer’s

The first spy symptoms are related to memory loss ( amnesia ), but it is good to keep in mind that there are different types of memory.

  • Episodic memory . It is divided into short-term memory (which retains information from the last hour) and long-term memory;
  • Semantic memory , which concerns the meaning of words;
  • Procedural memory , the reminder of how the tools are used.

Then there is Aphasia , the alteration in the ability to speak or understand, either by replacing one word with another or without finding the link between one term and another.
Another symptom is Agnosia , that is, the loss of the ability to recognize objects and what they are for.
Alongside these symptoms, sufferers present with personality changes and behavioral disturbances , including incontinence , aggression , and insomnia .

How Alzheimer’s disease evolves

The disease has a slow and progressive course , and we can identify three phases :

  1. In the initial phase, the main symptom is short- and medium-term memory deficit, generally minimized by the patient himself and relatives, which is often associated with a depressive reaction secondary to awareness of memory loss;
  2. In the second phase, the memory deficit is increasingly markedand is progressively accompanied by disturbances in attention, critical and judgment skills , language and difficulty in participating in work and family activities . Persecutory or paranoid thought disorders are not uncommon. The ability to carry out daily activities is impaired and the patient requires partial assistance;
  3. In the third phase, the memory deficit also affects the long-term componentand is associated with severe impairment of all the cognitive components described above. Thinking disorders can become accentuated and eventually be associated with hallucinations and delusions . In this phase, the patient is completely non-self-sufficient and therefore requires complete assistance .

Difficulty swallowing, difficulty moving, loss of weight and appetite, and increased sensitivity to infections may progressively appear .

Alzheimer’s disease treatment

Unfortunately, Alzheimer’s disease is not curable to date , but there are drugs that can improve cognitive symptoms for some time . These are inhibitors of acetylcholinesterase , an enzyme that destroys the neurotransmitter acetylcholine and helps in the early stages of the disease, and memantine .

Some hope for a new cure in treating patients with early or mild disease comes from a monoclonal antibody , aducanumab, currently (September 2020) under approval in the United States. At the beginning of 2019, the companies involved had decided to stop Phase III trials (ENGAGE and EMERGE), to evaluate the efficacy and safety of aducanumab, because the results did not seem to be those hoped for in slowing the cognitive and functional decline of patients. However, a larger data set became available in October that instead showed more promising results about the role of aggregate beta-amyloid removal , which may reduce the clinical decline of Alzheimer’s disease.

Meanwhile, we continue to study with a view to being able to play ahead, identifying the elements that can lead to the disease. A long-tried strategy to follow is to develop antibodies to beta-amyloid , but at the moment the results have not been satisfactory.

Another way is that of the very early diagnosis . For example, the English EDoN (Early Detection of Neurodegenerative diseases) project by Alzheimer Research UK is underway, which aims to understand the very early signs of dementia, not just Alzheimer’s. EDoNbrings together global experts in data science, digital technology and neurodegeneration to develop a digital tool for the early detection of diseases that cause dementia. The idea is to collect huge amounts of digital data donated by research study volunteers using smartphone apps and wearable devices , with the ultimate goal of developing a digital device that can detect these “fingerprints” in people who do not yet present obvious symptoms of dementia .
To stay up to date on ongoing studies and on the treatment prospects of Alzheimer’s disease, we recommend monitoring the Rare Diseases Observatory (OMAR) website. https : //www . Osservatoriomalattierare.it/alzheimer .

Alzheimer’s rehabilitation

Another effective method to counter the development of the disease is constituted by multidimensional “cognitive training” which makes use of mnemonic, concentration and orientation techniques, as well as strategies for remembering events and appointments.
Rehabilitation therapies are of different types:

  • Occupational therapy , to make the patient as autonomous as possible in their daily activities, such as washing, feeding;
  • Cognitive stimulation . Some examples: the creation of short stories, which help to fix memories and improve the command of language, the most common pastimes such as crosswords, cards or sudoku.
  • Rot or Reality Orientation Therapy , to support the patient’s spatial orientation;
  • Validation Therapy , a set of techniques to empathically communicate with the person;
  • Pet Therapy .

For families it is difficult management, but we are not alone. There are several associations, even with local branches. For example, we point out the Alzheimer Federation that supports caregivers.

Questions and answers

HOW LONG DO YOU LIVE WITH ALZHEIMER’S?

It depends on several aspects. The statistics speak of an average of 10 years, but each situation is different, depending on the severity of the disease, the rehabilitation that is put in place. Some patients even live for twenty years.

WHAT ARE THE CAUSES OF ALZHEIMER’S?

Only in 1% of patients does the disease have a genetic origin. In the rest of the cases the onset is sporadic. The triggering cause is not known, but the correlation between the disease and the alteration of the metabolism of the precursor protein of beta amyloid (called APP) is being studied, which leads to the formation of beta amyloid, a neurotoxic substance that accumulates in the brain progressively to neuronal death. As there is no known trigger, there are no targeted prevention methods.

WHAT HAPPENS IN THE BRAIN OF AN ALZHEIMER’S PATIENT?

From the morphological point of view, in Alzheimer’s disease the brain is reduced in weight and volume due to a widespread atrophy of the brain tissue. The characteristic anatomo-pathological changes are:

  • “Senile plaques”, amyloid aggregates in the extra-cellular space;
  • “Neurofibrillary degeneration”, protein deposits inside the nerve cell;
  • “Amyloid angiopathy”, amyloid-induced vascular damage.

HOW MANY TYPES OF ALZHEIMER’S ARE THERE?

Alzheimer’s is not a single disease, but we don’t know a great deal from a morphological point of view. An article published in Nature in 2017 identified a variability in the characteristics of the beta-amyloid protein clusters, which results in different types of disease: typical form, posterior cortical atrophy and rapid progressive.

HOW DO YOU RECOGNIZE AN ALZHEIMER’S PATIENT?

Like all dementias, it is characterized by a progressive loss of memory associated with a cognitive disorder such as loss of language, executive skills and critical or abstract thinking. The first spy symptoms concern memory loss (amnesia), then there is Aphasia, the alteration in the ability to speak or understand, either by replacing one word with another or without finding the link between one term and another. . Another symptom is Agnosia, that is, the loss of the ability to recognize objects and what they are for. Alongside these symptoms, sufferers present with personality changes and behavioral disturbances, including incontinence, aggression, and insomnia.

 

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