September 8, 2009

Brain disease, not age, shrinks brain

Aging appears not to shrink the brain, but people with early brain disease have smaller brains, Dutch researchers found.

Lead author Saartje Burgmans, a doctoral student of Maastricht University in the Netherlands, said the belief that healthy older brains are substantially smaller than younger brains may stem from studies that did not screen out people whose undetected, slowly developing brain disease was killing off cells in key areas.

The study tested participants in Holland's long-term Maastricht Aging Study who were free of neurological problems such as dementia, Parkinson's disease or stroke. Once participants were deemed otherwise healthy, they took neuropsychological tests, including a screening test for dementia, at baseline and every three years afterward for nine years.

The study participants were also given magnetic resonance imaging scans at year three of the study to measure seven different parts of the brain.

The study, published in the journal Neuropsychology, found that among the people whose cognition got worse, older participants had smaller brain areas than younger participants.

Therefore, the seeming age-related atrophy in gray matter more likely reflected pathological changes in the brain that underlie significant cognitive decline than aging itself, the study authors said in a statement.