Dementia Requires Multi-Pronged Attack
Reported November 13, 2009
(Ivanhoe Newswire) — The growing problem of dementia in aging societies requires a combination of therapies to treat multiple changes in the brain. Drugs currently in development to treat individual brain pathologies may be inadequate to deal with the overall burden of dementia in the population, according to researchers.
Dementia — problems with memory, language and judgment — is a growing social and clinical problem affecting a quarter of people 85 years or older — an estimated 35 million people worldwide. Paul Ince, of the University of Sheffield, and colleagues at the University of Cambridge conducted a study to estimate the relative contribution of known causes of dementia in the brain to dementia at death. Their research drew upon data from the Medical Research Council’s Cognitive Function and Ageing Study a major investigation into dementia in England and Wales that began in 1990.
A total of 456 participants in the study donated their brains for post-mortem examination, enabling researchers to estimate the contribution of each type of pathology to dementia in the population as a whole.
The main pathological contributors to dementia were clumps of proteins called plaques and neurofibrillary tangles regarded as the hallmarks of Alzheimer’s disease and blood vessel disease. Other contributing factors included age, markers of reduced brain size and atrophy of the hippocampus, which is involved in learning and memory.
The researchers concluded that dementia is often associated with mixed pathological changes. At death, many people had changes in the brain consistent with Alzheimer’s as well as those linked to vascular dementia.
The findings may be difficult to extrapolate to the living population, because most changes in the brain can only be established post-mortem, while abnormalities in the brains of people living with dementia may alter over time. Nevertheless, the findings suggest that drugs focusing on specific pathologies, while having a profound effect when a single disease process predominates, may do little to reduce the overall burden of dementia in societies with aging populations.
SOURCE: PLoS Medicine, November 10, 2009