Loss of motor function in preclinical Alzheimer’s disease

Abstract

Accumulating evidence suggests that Alzheimer’s disease (AD) has a long preclinical phase, during which time its characteristic pathology accumulates and patient function declines, but symptoms are insufficient to warrant a clinical diagnosis of dementia. There have been increasing reports of noncognitive symptoms, including loss of motor function, reported to be associated with incident AD. To understand the link between motor function and preclinical AD, this article examines: our understanding of motor function and its clinical assessment in cohort studies; the relationship of motor function and loss of cognition in older persons; risk factors for cognitive and motor decline; and the relation of post-mortem indices of AD and motor function prior to death. Together, these data suggest that age-related cognitive and motor decline may share a common causation. Furthermore, individuals with a clinical diagnosis of AD may represent the ‘tip of the iceberg’, since AD pathology may also account for a substantial proportion of cognitive and motor dysfunction currently considered ‘normal aging’ in older persons without dementia. Thus, AD may have a much larger impact on the health and wellbeing of our aging population

Keywords::

• Alzheimer’s disease
• cognitive decline
• dementia
• mild cognitive impairment
• motor decline
• preclinical AD

Financial & competing interests disclosure

This research was supported by National Institute on Aging Grants P30AG10161, R01AG15819 R01AG17917, R01AG24480, P01AG09466, R01AG30142 and K23AG23040, the Illinois Department of Public Health and the Robert C Borwell endowment fund. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.