Symptoms and evolution characteristic

On November 26, 1901, Aloïs Alzheimer, a German neurologist, examines for the first time a 51-year-old woman who forgets her name as she writes it. It was in 1906 that Dr. Alzheimer described the evolution of this particular and unknown disease until then that would soon be associated with his name. A century later, what is known about this affection?

Many more question marks

Alzheimer's disease affects 850,000 people over 65 in the United States today. The number of cases is estimated to reach 1,200,000 cases in 2020 and 2,100,000 cases by 2040.

Alzheimer's disease accounts for more than half of dementia cases, and nearly 75% of senile dementia.

Its symptoms are characterized by memory loss on recent events, disappearance of time markers (alternating day-night) and space, difficulty recognizing objects, language disorders, then aggression and Of the agitation.

These characteristics are sometimes referred to as the four A: amnesia, aphasia, agnosia and apraxia. The memory is first reached (amnesia), with the impossibility for the patient to record new events. Language disorders then appear (aphasia) and make communication difficult. The patient may sometimes be silent. The gestural awkwardness (apraxia) is accompanied by the loss of sensations (agnosia). The patient no longer recognizes his entourage. In a state of profound mental confusion, he may adopt attitudes of indifference, mutism or aggressiveness. The bed-ridden state is inevitable in the long term.

From the first symptoms to death, one can count between 3 and 20 years, or on average about ten years.

The causes and mechanisms of Alzheimer's disease are not all elucidated. It should be noted, however, that this is not a normal phenomenon of aging. It is a real chronic disease with progressive evolution. The disorders caused are caused by the neurons responsible for memory.

The disease is thus due to two concomitant phenomena

Why do these phenomena appear in some people from a certain age? The mechanisms are a mystery that researchers are trying to elucidate. Today, all agree that Alzheimer's disease has a multifactorial origin. Epidemiological studies have revealed many risk factors but no well-identified cause.

The abnormal accumulation of tau protein within neurons. Normally, it allows to organize the neural networks. From a certain age, it tends to accumulate. This natural dysfunction is encountered in all people over 70 years. But in excessive amounts, it can disrupt the functioning of the neurons and cause their destruction, called "neurofibrillary degeneration." The aggregation of toxic amyloid beta or Aβ peptides present in abnormal amounts. These proteins are in fact fragments of degradation of a protein called APP. It is the abnormal accumulation of toxic Aβ that leads to the formation of amyloid plaques or "senile plaques" visible in the brain of patients.