Changes in walking speed among older adults may spell early stage dementia, according to a new study.

Researchers found that changes in walking pace in later life may signal the early stages of a type of dementia known as mild cognitive impairment (MCI).

The study included 93 participants who were 70 or older and lived alone. Of the people 54 had no cognitive impairment, 31 had non-memory-related mild cognitive impairment and the remaining had memory-related mild cognitive impairment.

Participants were given memory and thinking tests and had their walking speed unobtrusively recorded for a span of three years by special infrared sensors that were installed in their homes.

"In our study, we used a new technique that included installing infrared sensors in the ceilings of homes, a system designed to detect walking movement in hallways," study author Hiroko Dodge of Oregon Health and Science University in Portland said in a journal news release.

"By using this new monitoring method, we were able to get a better idea of how even subtle changes in walking speed may correlate with the development of MCI," he added.

Participants were assigned to groups of slow, moderate or fast based on their average weekly walking speed and how much their walking speed changed at home.

Researchers found that people with non-memory related mild cognitive impairment were nine times more likely to be slow than moderate or fast walkers and the amount of the fluctuation in walking pace was also significantly associated with mild cognitive impairment.

"Further studies need to be done using larger groups of participants to determine whether walking speed and its fluctuations could be a predictor of future memory and thinking problems in the elderly," said Dodge.

"If we can detect dementia at its earliest phases, then we can work to maintain people's independence, provide treatments and ultimately develop ways to prevent the disease from developing. Our in-home monitoring approach has a lot of potential to be used for sustaining independence of the elderly," Dodge added.

The findings are published in the journal Neurology.