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