Alzheimer's disease — the progressing form of senile dementia leading to full loss of cognitive abilities developing mainly after 60-65 years. It is clinically shown by the disorder of cognitive abilities arising gradually and constantly progressing: attention, memory, speech, praksis, gnozis, psychomotor coordination, orientation and thinking. Careful collecting the anamnesis, brain PET, an exception of other types of dementia by means of EEG, KT or MRT allows to diagnose Alzheimer's disease. Treatment is palliative, includes medicamentous (cholinesterase inhibitors, ) and psychosocial (art therapy, psychotherapy, touch integration, presence simulation) therapy.
Alzheimer's disease received the name by last name the German psychiatrist for the first time described it in 1906. Incidence on average fluctuates from 5 to 8 people for 1000 of the population that makes about a half of all cases of diagnosis of dementia. On a global scale according to 2006 the number of the patients having Alzheimer's disease made 26,5 million people. The accurate tendency of growth of incidence is noted that does a problem of diagnostics and treatment of this pathology of one of important problems of modern psychiatry and neurology.
Considerable correlation between incidence of dementia of altsgeymerovsky type and age is characteristic. So, in age group of 65 years about 3 cases of a disease on 1000 people are noted, and among aged people there are 95 years already of 69 cases for 1000. The indicator of prevalence of this pathology in the developed countries is much higher as their population has big life expectancy. Alzheimer's disease occurs among women more often than among men that partially connect with higher, in comparison with men, lasting their lives.
Etiology and pathogenesis of Alzheimer's disease
Still remains to dementia of altsgeymerovsky type a riddle for scientists and practicians in the field of medicine. Connection with any external factors starting Alzheimer's disease is not established. It is known only that a morphological substratum of a disease is formation of vnutrineyronalny neurofibrillar textures and cerebral congestions beta , so-called "senile plaques" that leads to a degeneration and death of neurons. Also lowering of the level of a holinatsetiltransferaza is noted. These features formed the basis of 3 main hypotheses trying to explain how Alzheimer's disease develops.
Older is the holinergichesky theory of developing of a disease connecting it with deficiency of acetylcholine. However results of clinical trials showed inability of medicines of acetylcholine at least partially or to temporarily stop Alzheimer's disease. The amyloid hypothesis of development of a disease exists since 1991. According to it a basis of pathology are congestions beta . It is interesting that the gene coding protein predecessor beta is a part of the 21st chromosome which trisomiya is the cornerstone of a Down syndrome. At the same time at all patients with a Down syndrome who reached 40-year age altsgeymer-like pathology is observed.
Pathological beta insufficiency of processes of mitochondrial oxidation, sourer reaction of the intercellular environment, the increased number of free radicals are called the contributing factors of synthesis. Deposits of a pathological amiloid are noted both in a brain parenchyma, and in walls of cerebral vessels. It should be noted that similar deposits characterize not only Alzheimer's disease, they are observed at cerebral hematomas of congenital genesis, a Down syndrome and at normally proceeding aging processes.
On the third hypothesis Alzheimer's disease is connected with death of neurons as a result of accumulation in them of a giperfosforilirovanny tau-protein which threads stick together and form balls. According to a tau-hypothesis accumulation of protein is connected with defect in its structure; formation of textures causes disintegration of vnutrineyronalny transport that in turn leads to violation of signaling between neurons, and then and to their destruction. On the other hand, formation of neurofibrillary tangles is observed also at other cerebral degenerations (for example, at the progressing nadjyaderny paralysis and a frontotemporalny atrophy). Therefore many researchers deny independent pathogenetic value of tau-protein, including its accumulation by a consequence of mass destruction of neurons.
Among the possible reasons starting Alzheimer's disease call synthesis of a pathological apolipoprotein E. Posledny has affinity to an amyloid protein and takes part in tau-protein transportation that can be the cornerstone of the typical morphological changes of a disease described above.
According to many researchers Alzheimer's disease is genetically determined. 5 main genetic sites with which connect development of a disease are defined. They are located on 1, 12, 14, 19 and 21 chromosomes. Mutations in these loci lead to the violations of protein exchange of cerebral fabrics involving accumulation of an amiloid or tau-protein.
Alzheimer's disease symptoms
In typical cases Alzheimer's disease demonstrates at persons 60-65 years are more senior. Extremely seldom the cases of an early form of a disease arising during from 40 to 60 years meet. Dementia of altsgeymerovsky type is characterized by the hardly noticeable and long beginning, steady progressing without the periods of improvement of a state. The main substratum of a disease are disorders of the highest nervous functions. Treat the last: short-term and long-term memory, attentiveness, existential orientation, psychomotor coordination (), ability to perception of various aspects of the outside world (), speech, control and planning of the highest psychological activity. Alzheimer's disease is subdivided into 4 clinical stages: predemention, early, moderate and heavy dementia.
At a stage of a predemention there are hardly noticeable cognitive difficulties often revealed only during detailed neurocognitive testing. From the moment of their emergence before verification of the diagnosis, as a rule, there pass 7-8 years. In most cases into the forefront there are violations of memory to recent events or information obtained the day before, considerable difficulties if necessary to remember something new. Some problems with executive functions: cognitive flexibility, ability to concentrate, planning, abstract thinking and semantic memory (the complicated recall of value of some words) usually remain unnoticed or "are written off" for the age of the patient and physiologic processes of aging happening in its brain structures. At a stage of a predemention the apathy which is the typical neuropsychiatric symptom which is steadily present at all stages of a disease can be observed.
Small expressiveness of symptoms of a predemention allows to carry it to a preclinical stage of a disease after which more expressed cognitive changes characterizing actually Alzheimer's disease develop. This stage is called as a number of authors as soft cognitive frustration.
The progressing memory impairment leads to so expressed symptoms of its violation what to carry them to processes of usual aging it is impossible to become. As a rule, it also is a reason for the assumption of the diagnosis "Alzheimer's disease". At the same time different types of memory are broken in various degree. Most short-term memory — ability to remember new information or recent events suffers. A little such aspects of memory as unconscious memory of the actions (implicit memory) learned earlier, memoirs of the remote events of life (incidental memory) and the facts (semantic memory) learned once long ago suffer. Disorders of memory often are followed by agnosia symptoms — violations of acoustical, visual and tactile perception.
Certain patients to the forefront in clinic of early dementia have disorders of executive functions, apraxia, agnosia or violations of the speech. The last are characterized mainly by decrease in tempo of speech, impoverishment of a lexicon, ability easing in writing and orally to express the thoughts. However at this stage during communication the patient quite adequately operates with simple concepts.
Because of frustration of a praksis and planning of movements when performing tasks with use of thin motility (drawing, sewing, the letter, clothing), the patient has a clumsy appearance. In a stage of early dementia of the patient it is still capable to carry out many simple tasks independently. But in the situations demanding difficult cognitive efforts it needs the help.
The progressing oppression of cognitive functions leads to considerable decline in the ability to make independent actions. Obvious are agnosia and speech disturbance. The parafraziya — loss of a grammatical system of the speech and its sense as instead of the forgotten words patients even more often use incorrect words is noted. It is followed by loss of writing skills (dysgraphia) and readings (dyslexia). The accruing frustration of a praksis deprives of the patient of ability to cope even with simple daily tasks, such as clothing undressing, independent meal and so forth.
In a stage of moderate dementia changes in long-term memory, earlier unaffected are observed by a disease. Violations of memory progress to such an extent that patients do not remember even the immediate family. Neuropsychiatric symptoms are characteristic: emotional lability, sudden aggression, tearfulness, opposition to leaving; vagrancy is possible. Approximately at 1/3 patients with Alzheimer's disease the syndrome of false identification, etc. manifestations of nonsense comes to light. There can be an urine incontience.
The speech of patients comes down to the use of separate phrases or single words. Further speech skills are completely lost. At the same time the long time remains ability to perceive and support emotional contact with people around. Alzheimer's disease in a stage of heavy dementia is characterized by full apathy though aggressive manifestations can sometimes be observed. Patients are exhausted both mentally, and physically. They are incapable to make independently even the simplest actions, hardly move and finally cease to rise from a bed. There is a loss of muscle bulk. Because of an obezdvizhennost such complications as stagnant pneumonia, decubituses, etc. develop. Complications cause finally a lethal outcome.
Diagnosis of Alzheimer's disease
One of the main directions of diagnostic search is collecting the anamnesis and complaints. As the patient at early stages of a disease often does not notice the changes happening to it, and at development of dementia cannot adequately estimate the condition, survey has to be conducted among his relatives. Are important: impossibility to precisely define the beginning of cognitive deviations, instructions on the gradual and steadily progressing nature of aggravation of symptoms, absence in the anamnesis of cerebral diseases (encephalitis, an intracerebral tumor, abscess of a brain, epilepsy, chronic ischemia transferred ONMK, etc.) and craniocereberal injuries.
It is quite difficult to diagnose Alzheimer's disease in a predemention stage. During this period only expanded neuropsychological testing can reveal some violations of the highest nervous functions. During the research patients are offered to remember words, to copy figures, to perform difficult arithmetic operations, to read and retell read.
For the purpose of an exception of other diseases capable to lead to development of dementia, the neurologist performs neurologic inspection, appoints additional inspections: EEG, REG, Ekho-EG, brain KT or MPT. A certain value in confirmation of the diagnosis has identification of deposits beta when carrying out PET of a brain with introduction of the Pittsburgh structure of B. It is lately proved that as one more marker of a disease detection of a tau-protein or beta can serve in the tserebrospinalny liquid taken on the analysis by a lyumbalny puncture.
Treatment of Alzheimer's disease
Unfortunately, methods of treatment available today are incapable to cure Alzheimer's disease or to slow down its current. All attempts of therapy are in fact palliative and can facilitate symptoms only slightly.
The most recognized medicamentous schemes include and antikholinesterazny medicines. Miemangting is inhibitor of glutamate receptors which excessive activation characterizes Alzheimer's disease and can lead to death of neurons. The moderate effect of a memantin at moderate and heavy dementia is noted. At its reception side effects are possible: dizziness, confusion, headaches, hallucinations.
Cholinesterase inhibitors (, donepezit, ) showed moderate efficiency in attempts to treat Alzheimer's disease in a stage of early and moderate dementia. Donepezil can be applied at heavy dementia. Use of inhibitors of a cholinesterase in a stage of a predemention could not warn or slow down development of symptoms. Treat side effects of these medicines: bradycardia, weight reduction, anorexia, muscular spasms, gastritis with the increased acidity.
In cases when Alzheimer's disease is followed by antisocial behavior, for knocking over of aggression purpose of anti-psychotics is possible. However they can cause tserebrovaskulyarny complications, additional decrease in cognitive functions, motive frustration and at long use increase mortality of patients.
Along with pharmacological psychosocial methods of treatment of the patients having Alzheimer's disease are applied. So, the supporting psychotherapy is directed the help to patients with early dementia to adapt to the disease. In stages of more expressed dementia art therapy, the touch room, therapy by memoirs, presence simulation, touch integration, validation therapy is used. These techniques do not lead to clinically significant improvement, however, according to many authors, they reduce uneasiness and aggression of patients, improve their spirit and thinking, soften separate problems (for example, an urine incontience).
Forecast and prevention of Alzheimer's disease
Unfortunately, Alzheimer's disease has the unfavourable forecast. Steadily progressing loss of the major functions of an organism leads to a lethal outcome in 100% of cases. After diagnosis life expectancy on average makes 7 years. Less than 3% of patients live more than 14 years.
As Alzheimer's disease is an important social problem in the developed countries, is conducted many researches designed to define the factors reducing probability of its development. However similar researches provide contradictory data and still there are no firm proofs of preventive value at least one of the considered factors. Many researchers are inclined to consider intellectual activity (love to reading, hobby for chess, solving of crossword puzzles, knowledge of several languages, etc.) the factor which is distancing an onset of the illness and slowing down its progressing. It is noted also that causal factors of development of cardiovascular pathology (smoking, diabetes, increase in level of cholesterol, arterial hypertension) cause heavier course of dementia of altsgeymerovsky type and can increase risk of its emergence.
Due to the aforesaid to avoid Alzheimer's disease and to slow down its current, it is recommended to lead a healthy lifestyle, to stimulate thinking in any age and to carry out physical exercises.