Alzheimer's Disease

Alzheimer's disease is a neurodegenerative disease of the brain that causes progressive and irreversible loss of mental functions. It is the leading cause of dementia among older people, affecting about 24 million people worldwide.

The process responsible for the neurodegenerative disease is still poorly understood: it is due to the formation of amyloid plaques and tau protein aggregates forming the neurofibrillary degeneration. The cortical atrophy resulting in a key first time the internal temporal lobe (including the hippocampus) and the frontal cortex and associative temporo-parietal at a later stage.

The exact cause is still unknown, but it is assumed that environmental and genetic factors contribute. Mutations in at least four genes predisposing to Alzheimer's disease have been identified. They are particularly involved in familial cases early onset, which represent less than 5% of patients with Alzheimer's disease. For the so-called sporadic form of Alzheimer's disease, an increasing number of susceptibility genes (such as ApoE) have been identified.

Until the 1960s, it was assumed that the disease was rare, but later we found that in many cases, what was taken for normal aspects of senescence was in fact the disease.

The first symptom is loss of memory of recent events (amnesia) and is manifested initially by minor distractions that are gradually with the progression of the disease, while older memories are relatively preserved. Thereafter, the cognitive deficits extend to areas of language (aphasia), the organization of movements (apraxia), recognition visual (Agnosia) and executive functions (such as decision making and planning) . These symptoms reflect in particular the pathological process of degeneration reaching the frontal lobes of the brain. These changes affect the psychological qualities essential and for this reason the disease is sometimes described as a disease in which victims suffer loss of qualities that form the essence of human existence.