Combination therapies to tackle multiple changes in the brain could perhaps be required to combat the increasing problem of dementia in ageing societies. Atleast this what scientists from the University of Sheffield and the University of Cambridge claim.
Dementia apparently involves problems with memory, language and judgement. Moreover, it seems to be a rising social and clinical problem disturbing a quarter of people 85 years or older. It was estimated that it affects nearly 35 million people all across the world.
The authors were believed to have carried out the study to calculate approximately the relative contribution of identified causes of dementia in the brain to dementia at death. This existing study is known to have been drawn upon data from the Medical Research Council’s Cognitive Function and Ageing Study.
This earlier study appears to be a major analysis into dementia in England and Wales that began in 1990. In addition, the experts were noted to have made use of statistical methods in order to establish the proportion of dementia directly attributed to each definite change in the brain and other factors.
In this current study, 456 people appear to have donated their brains for post-mortem examination after death. Apparently, this enabled the scientists to make a guess of the contribution of each type of pathology to dementia in the population as a whole.
The authors found that the main pathological contributors to dementia seem to have been bunches of proteins called plaques and neurofibrillary tangles i.e. 19 percent and blood vessel disease i.e. 21 percent. Moreover, plaques and neurofibrillary tangles are known to be regarded as the hallmarks of Alzheimer’s disease.
Other factors contributing to the risk of dementia across the population appear to have included age i.e. about 18 per cent, and markers of reduced brain size also known as atrophy including lower brain weight compared to people of the same sex which comprised 17 percent. Furthermore, atrophy of a structure called the hippocampus which is involved in learning and memory contained nearly 16 percent.
“This research shows that the assertion that Alzheimer’s Disease is the commonest form of dementia is simplistic, but it also raises important issues about what factors determine whether a person becomes demented or not in the face of accumulating brain disease in old age,” explains Professor Paul Ince, from the School of Medicine and Biomedical Sciences at the University of Sheffield.
“Some people seem to retain their intellect despite high levels of pathology. Knowing why would open new avenues in developing therapies to delay dementia onset,” he continues.
The findings of the study revealed that multiple abnormal or pathological processes inside the brain appear to be frequently involved in cases of dementia. In addition, the drugs at present in development to treat individual brain pathologies may have a restricted impact on the overall burden of dementia in the population.
The authors concluded that dementia seems to be often associated with a mixture of pathological changes. This in turn signifies that at death, many people seem to have changes in the brain consistent with both Alzheimer’s and vascular dementia. It was observed that the findings have represented the current best estimation of the pattern of dementia for the living population. This is because many changes in the brain, and especially mixed pathology could perhaps be only recognized by post-mortem.
The study also suggests that individual use of drugs focusing on specific pathologies may do little to lessen the overall burden of dementia in societies with ageing populations. These specific pathologies appear to have a deep effect in the smaller proportion of cases in which a single disease process prevails. Besides, an effective strategy for the population will perhaps require a range of protective strategies linked to biomarkers for each major risk factor.
The findings of the study have been published in the journal, PLoS Medicine.