Alzheimer’s disease – symptoms and causes
Alzheimer’s disease was discovered at the beginning of the 20th century. Dr. Alois Alzheimer first described the disease in 55 year old woman with a fast developing senile dementia, who died several years after the beginning of symptoms. Special about this woman was that her age didn’t meet the level of reduction of the intellect.
Occurrence of senile dementia at that time was a characteristic symptom of the elderly. Later, Alzheimer’s disease was called ”disease of the century” and in recent decades came numerous data about its widely spread. It is estimated that over one million Americans suffer from this disease. In practice this is more than half of all patients in the U.S. with symptoms of senile dementia.
Causes of Alzheimer’s disease
Genetic theory – in 5-10% of cases of Alzheimer’s disease is established an autosomal dominant disease transmission. Also is discovered a connection between Alzheimer’s disease and Down syndrome with common genetic defect in chromosome 21. At the same chromosome is encoded synthesis of amyloid protein of the nervous system, superoxide dismutase and interferon and they do relate to aging.
Toxic theory - in the brains of patients suffering from Alzheimer’s disease are found high concentrations of aluminum. This give reason to believe that the aluminum ions from utensils, cans for beer and soft drinks, cooking aluminum foil enter the body, accumulate in the brain and damage it.
Viral theory – discusses infection with “slow” virus, whose incubation period lasts decades. The virus could stay dormant for years in sleeping position and at some point to be initiated and to intensify direct damage to neurons in the brain. Immune theory – discusses the possibility of formation of autoantibodies against brain tissue.
Biochemical theory – in patients with Alzheimer’s disease is established a low lever of mediator acetylcholine, which is believed to be due to late onset of biochemical defect in the brain enzyme systems. Reduction of acetylcholine is most pronounced in the cerebral cortex, hippocampus and nucleus amigdalis. There is loss of neurons in the basal ganglia, which are the main source of acetylcholine to the neocortex.
Symptoms in Alzheimer’s disease – loss of skills (reading, writing, computing); foget fullness of facts and dates of everyday life and the past, confusion and disorientation, forget fullness and inability to concentrate; lower intellect, easy irritability, periods of loss and recovery knowing (in the early stages).
Changes in the brain in Alzheimer’s disease – the brain of patients is greatly reduced in size (extreme atrophy). Sulcuses are narrowed and depressed and the furrows between them – relatively advanced. This change is diffuse, but is more pronounced in the frontal, temporal and parietal lobes of the brain. Microscopic is established loss of 35-40% of neurons in the cortex. Characteristic degenerative changes in the brain substance are also found. These include focal deposition of amyloid, formation around is of the so called neurofibril nodes, neuritic (senile) plaques, granular vacuole degeneration and bodies of Hirano.