Not just Alzheimer's
Doctors have discovered a new form of dementia
Sergey Vasiliev, Naked Science
The most common form of senile dementia – Alzheimer's disease – remains a big mystery to science. The specific cause of its development is unknown, although it has been established that the key factor of disorders is the accumulation of amyloid plaques in brain cells – very stable and dense clumps of small amyloid proteins that interfere with the normal activity of cells and their supply, eventually leading to death.
So, only last year, doctors stated that at least 20 percent of cases of diagnosed Alzheimer's disease are accompanied by the accumulation of amyloid TDP-43 and are a completely separate form of dementia, which is called LATE (Limbic-Predominant Age-Related TDP-43 Encephalopathy, mainly limbic age-Related TDP-43 encephalopathy).
New work by Eric Abner and his colleagues from the University of Kentucky has shown that this is not limited to this either. Symptoms that are usually attributed to Alzheimer's disease can serve as a manifestation of another form of dementia associated with the formation of plaques of four abnormal proteins. Scientists write about this in an article published in the journal JAMA Neurology (Karanth et al., Prevention and Clinical Phenotype of Quadruple Misfolded Proteins in Older Adults).
The authors studied detailed brain autopsy data from 375 patients who participated in a special program for the study of neurodegenerative diseases. Approximately one in five of the plaques revealed not only the three above-mentioned proteins, but also alpha-synuclein, which is usually associated with a completely different neurodegenerative disease, Parkinson's disease. For lack of an official name, scientists have described this syndrome as "four incorrectly packaged proteins" (Quadruple Misfolded Proteins, QMP).
All volunteers with QMP were monitored by doctors for more than ten years before their death, which allowed to trace their medical history. It turned out that in people in whose tissues plaques from all four amyloids were found, neurodegenerative processes and symptoms developed especially rapidly. However, it is not yet known how the accumulation of different proteins is related to each other. Apparently, beta-amyloid begins to be deposited first, but whether it stimulates the formation of plaques of the other three proteins or whether it occurs independently remains to be determined.
"All this is not very good news," he sums up Eric Ebner, –because it means that even if we completely defeat Alzheimer's disease, we will still have to deal with TDP-43 and alpha-synuclein, which are also quite common in old age."
Portal "Eternal youth" http://vechnayamolodost.ru