Experiencing excessive daytime sleepiness as an older adult can spell dire consequences that ultimately may lead to full-blown dementia, according to a new study funded by the National Institute on Aging.

Excessive daytime sleepiness could be an early sign of a pre-dementia condition called motoric cognitive risk syndrome (MCR), a study suggests.

Predementia is a term used to describe the cognitive impairment symptoms in the early stages of Alzheimer's disease.