Alzheimer's: the real signals for a correct diagnosis
Posted: 26 Apr 2011 11:35 PM PDT
The Journal of the American Association Alzheimer outlines the main diagnostic criteria for the three stages of the disease.
A woman aged 85 years is often mistaken dates, names sometimes, regularly repeats the same phrases. His daughter, a doctor, suspected early Alzheimer's. Should we consult? Make tests? Wait a precise medical diagnosis? Older people with impaired memory in France are still far from all be an accurate diagnosis to determine whether the onset of Alzheimer's disease. The National Institute of Aging in the United States announced last week for the first time in twenty-seven years, new guidelines for the diagnosis of Alzheimer's disease, dementia the most common among the elderly. These recommendations are based on four articles to be published in May in the journal Alzheimer's & Dementia, which sets out the criteria for asserting the presence of the disease.
In France, this condition for about 800,000 people, most of them have also not received a diagnosis in good and due form. Why these new recommendations? "Research on Alzheimer's has evolved over the last twenty five years. We must adjust the diagnostic criteria to reflect these advances. This is necessary to encourage and accelerate research that will benefit patients, "said in a statement Dr. Richard Hodes, director of the National Institute of Aging attached to the National Institutes of Health (NIH).
This update reflects "a major change in how medicine seen and studied this disease," within the NIH and the Alzheimer's Association, who led the project. Without effective treatment, why wear a precise diagnosis of this disease? On the one hand, physicians responded that a non-drug treatment (stimulation, support, anticipation of a future organization of lifestyle) is always possible. Importantly, these recommendations classify the disease in three different stages, preclinical (asymptomatic), mild cognitive impairment (memory impairment limited) and finally dementia (final stage of the disease). While their interest is to define the tools to detect early forms of harmonized manner with the aim to conduct large scale clinical trials on large groups and homogeneous patient meeting the same diagnostic criteria.
These recommendations will be useful in diagnosing patients, for a start therapy, when effective drugs will be available ... But we're not there yet.
The new guidelines cover all stages of the disease which evolves very gradually over several years. It may in fact cause changes in the brain a decade or more before it becomes obvious.
Recommendations hold three phases.
The first, entitled "Preclinical" before the disease symptoms are evident, is that where changes occur in the brain and in particular an early accumulation of senile plaques composed of a protein capable of causing death neurons. At this stage, abnormalities in the cerebrospinal fluid (obtained by lumbar puncture) and anatomical damage detectable by brain imaging (MRI, PET scan) are already visible. However, many uncertainties exist about the long-term significance of these signs.
The second phase is the first sign (mild cognitive impairment), such as memory loss, but without significant impact on the independence of the individual concerned. "People with these symptoms will not necessarily see a move towards Alzheimer's disease," say the authors of these guidelines.
The third and last phase is that of dementia as previously described by medicine, memory loss, loss of learning, confusion, disorientation in time and space, dependence ...
Researchers use more biomarkers (measured in blood or cerebrospinal fluid) in the early stages of the disease in their http://www.blogger.com/img/blank.gifrecherche
to track the evolution evil. They can not be used routinely, especially due to inadequate validation.
Early clinical criteria for Alzheimer officially established in 1984 described this condition in one stage of dementia. We had to wait for the autopsy showing an aggregation of amyloid plaques and protein "tau" in some areas of the brain to confirm the diagnosis.
The disorder first described in 1907 by German psychiatrist Alois Alzheimer's most often appears after age 65. Its frequency increases with age.