Alzheimer--certitudes and hypotheses.

Alzheimer's disease is a degenerative, progressive and irreversible condition, which affects cognitive functions. It was first described in 1907, by the German physician Alois Alzheimer. Although at the time, it was considered a rare disease, in 2010 in the world were estimated 35.6 million cases of dementia, most of these with the diagnosis of Alzheimer's disease. Typical neuropathologic lesions are represented by the amyloid plaques, neurofibrilar tangles and synapses and neurons losses. It was hypothesized that the amyloid protein has prion-like properties. Even from the first descriptions of the disease, atypical features were observed - the second case described by the physician Alois Alzheimer, had only plaques, the tangles were missing. About 19 % of the healthy old subjects present in the brain the same lesions as Alzheimer's cases, while in 10 % of the cases of disease, in necropsy are present only the plaques or only the tangles. These aspects are even more paradoxical, as the certain diagnosis is established only at necropsy, on anatomopathological lesions. Even so, the international diagnosis criteria, based on clinical aspects, can establish a certain, probable or a possible diagnosis. It exist an early-onset form, as well as a late-onset form of disease (which appears after 80-85 years of life); genes are involved in the genesis of the disease. A lot of money are spent to find an efficient medication in the treatment of the disease (tramiprosate--an amyloid-antagonist, Dimebon, gamma-secretase inhibitors or a vaccine--a synthetic form of the amyloid protein); for the moment the used medication may at its best only to temporary improve the symptoms. Some scientists believe that approx. 30 % of the cases are wrongly diagnosed with Alzheimer, being in fact other forms of dementia, or that we deal with several biologic processes, generating rather an Alzheimer's syndrome, meanwhile others are unsatisfied by a poor diagnosed disease and its popular receipt as a part of the normal aging process.