Alzheimer’s disease
Alzheimer’s disease is the disease of the brain that usually manifests after 50 and characterizes by the progressing cognitive and memory disorders and personality change. Genetic predisposition is considered to play the key role in the Alzheimer’s disease. The defects of the mitochondrial DNA have been detected in about 50% of the cases (502500, MTND1 gene, mitochondrial inheritance). Early onset is associated with defects of the genes АРР, PSEN1, PSEN2. The disease can be considered a group of diseases of different origin and general pathogenesis: all known gene defects modify the processing of the amyloid precursor, the protein, that leads to the emergence of neurotoxic form of the proteins. In Alzheimer’s disease, multiple plaques, the amyloid proteins deposits, form in the brain tissue; they induce degeneration of the neurons and neuronal processes. Early (before 65, type II) onset and late (after 65, type I) onset are distinguished. The disease is diagnosed on the basis of the clinical picture after all similar diseases are excluded. The diagnosis is confirmed at autopsy, by counting the senile plaques and neurofibrillary tangles. There is no molecular-genetic diagnostic of this disease. The molecules of beta-amyloid and neurofilaments in blood and cerebrospinal fluid (CSF) can be detected in blood, when over 50% of the cortical neurons are dead, and the patients cannot be helped.
The following diagnostic symptoms are observed in Alzheimer’s disease: gradual onset and progressing course, memory disorder, reduction of the intellect, disorder of the abstract thinking, disorder of higher cortical functions and reduced critic of own mental state.
At early stages, the patient preserves a critical attitude, so, depressions and suicidal states are possible. The patient develops changes in the personality, disorientation in space, time and personality, psychomotor excitement, inability to socially adapt. The disease might be accompanied by the hallucinations and delirium. Late signs include fits and muscular spasms.
