Reading the newspaper, writing
letters, visiting a library, attending a play or playing games such as chess or
checkers, are all activities that can contribute to a healthier brain in
seniors, according to new research. A study presented at the annual meeting of
the Radiological Society of North America (RSNA) shows that these activities
can preserve structural integrity in the brains of older people.
Konstantinos Arfanakis, Ph.D.,
and colleagues from Rush University Medical Center and Illinois Institute of
Technology in Chicago studied what effect cognitive activity might have on the
older brain’s white matter, which is composed of nerve fibers or axons that
transmit information throughout the brain. The researchers used a magnetic
resonance imaging (MRI) method known as diffusion tensor imaging (DTI) to
generate data on diffusion anisotropy, a measure of how water molecules move
through the brain.
The researchers explain that in
white matter, diffusion anisotropy exploits the fact that water moves more
easily in a direction parallel to the brain’s axons, and less easily
perpendicular to the axons, because it is impeded by structures such as axonal
membranes and myelin. “This difference in the diffusion rates along different
directions increases diffusion anisotropy values,” Arfanakis said. “Diffusion
anisotropy is higher when more diffusion is happening in one direction compared
to others.”
The anisotropy values in white
matter drop, however, with aging, injury and disease, he noted. “In healthy
white matter tissue, water can’t move as much in directions perpendicular to
the nerve fibers,” he said. “But if, for example, you have lower neuronal
density or less myelin, then the water has more freedom to move perpendicular
to the fibers, so you would have reduced diffusion anisotropy. Lower diffusion
anisotropy values are consistent with aging.” The study included 152 elderly
participants, mean age 81, from the Rush Memory and Aging Project, a study
looking at risk factors for Alzheimer’s disease.
Participants were without
dementia or mild cognitive impairment, based on a detailed clinical evaluation,
according to the researchers. They asked the participants to rate on a scale of
1 to 5 the frequency with which they participated in a list of mentally
engaging activities during the last year. Among the activities were reading
newspapers and magazines, writing letters and playing cards and board games. Participants
underwent brain MRI using a 1.5-T scanner within one year of clinical
evaluation. The researchers collected anatomical and DTI data and used it to
generate diffusion anisotropy maps.
Data analysis revealed
significant associations between the frequency of cognitive activity in later
life and higher diffusion anisotropy values in the brain, according to the
study’s findings. “Several areas throughout the brain, including regions quite
important to cognition, showed higher microstructural integrity with more
frequent cognitive activity in late life,” said Arfanakis. “Keeping the brain
occupied late in life has positive outcomes.”
According to the researcher,
diffusion anisotropy drops gradually beginning at around age 30. “Higher
diffusion anisotropy in elderly patients who engage in frequent cognitive
activity suggests that these people have brain properties similar to those of
younger individuals,” he said. He added the researchers will continue to follow
the study participants with an eye toward comparing the diffusion anisotropy
results over time. “In these participants, we’ve shown an association between
late-life cognitive activity and structural integrity, but we haven’t shown
that one causes the other,” he said. “We want to follow the same patients over
time to demonstrate a causal link.”
Source: Psych Central
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