Change in gait could be early sign of mental decline, Alzheimer's

In the patterns that emerged in the study, certain cognitive domains were only associated with certain aspects of gait. Information processing speed was linked with rhythm. Executive function was linked to pace and variability. Fine motor speed was associated with tandem.

A Mayo Clinic study indicates that walking changes happen because the neurodegenerative disease impairs communication between different parts of the brain. "Walking and movements require a perfect and simultaneous integration of multiple areas of the brain," study author Rodolfo Savica told the Detroit Free Press.

Mayo researchers measured the walk, including rhythm, speed and stride length, of more than 1,341 participants at intervals of about 15 months. Those whose gaits faltered in those measures had a great deal more overall cognition, memory and executive function decline.

An annual test may not tell the story, noted researcher Dr. Lisa Silbert of Oregon Health and Science University in Portland, who studied 19 cognitively-sound volunteers, measuring gait speed during MRIs and at home. Participants walked faster in the lab. Her research indicated an association between slower in-home speed over time and smaller volume of hippocampus, the section of the brain linked to memory.

"Walking speed taken at a single time point may overestimate walking abilities in the elderly," Silbert said. "Our data suggests that continuous in-home monitoring may provide a more accurate reflection of walking speed and may be more sensitive at detecting motor changes associated with future cognitive decline," she said in a release about the research.

Japanese researchers also noted a link between gait and mental ability. In a study from the Tohoku University Graduate School of Medicine in Sendai, Japan, researchers looked at 525 community-dwelling persons 75 and older, examining demographics, medical history and general physical and mental health. The subjects each walked as fast as they could for six meters while the scientists studied gait pattern, speed and stride length. Looking at MRIs, they found that gait velocity and atrophy in the entorhinal cortex, a kind of center in the brain that deals with memory and navigation, were closely related.

"Our research found that gait velocity was significantly decreased as the severity of dementia symptoms increased," said Kenichi Meguro, lead researcher. "Gait should no longer be considered a simple, automatic motor activity that is independent of cognition. They are linked."

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