New Study Examines Gait Speed as Being Related to Future Dementia
Dementia is a prominent concern among the older adult population. As the elderly population continues to increase, the number of those with dementia also will increase in number. Recent research on dementia and cognitive impairment in the aging has targeted a new disorder and with it, a new symptom that may be related to the likelihood of acquiring dementia.
A recently newly defined disorder found among older adults, referred to as motoric cognitive risk syndrome (MCR) is characterized by cognitive decline with motor-based symptoms. The disorder appears to be common in older adults. However, those that have the disorder also appear to be at greater risk of developing further cognitive impairment that leads to various forms of dementia, including Alzheimer's disease. In fact, those that developed MCR were approximately two times more likely to develop dementia.
The current syndrome, motoric cognitive risk syndrome, is diagnosed by simple questions related to memory as well as measuring gait speed over a fixed distance. MCR is able to be diagnosed independent of cognitive tests. The group under study was composed of 26,802 older adults, with an average age of 71.6 years. Slightly more than half of the sample was women. There were 22 cohorts from 17 different countries that made up the sample.
Gait speed was measured using a stop watch and measuring the fixed distance that one walks within a given period of time. The average or mean gait speed was 81.8 cm/s, which is slightly less than three feet traveled per second. Those who were one standard deviation below the average walking speed were viewed as slow walkers and therefore comprised motorically.
The finding showed that those that were diagnosed with MCR had worse performance on all cognitive tests than those who were not diagnosed with MCR. Those with MCR also had a higher prevalence of disease, especially vascular diseases. The diagnosis of Motoric Cognitive Risk Syndrome has appeared to be able to have important predictive value as well. As Dr. Joe Verghese, lead study author states, "You would expect that the people who actually have dementia but are being classified as MCR would meet dementia criteria pretty soon over the next 2 or 3 years, but if you take them out, that would suggest that MCR can predict beyond the initial few years and capture cases that are going to develop dementia more than 3 years out."
The study emphasized the importance of gait speed as being an important predictor of future dementia. As Dr. Verghese states, gait speed is highly reliable and has been a very sound predictor of health outcomes. In addition, gait speed measurements are simple, highly accessible, and easily done in most health care settings. However, he also stated that it may not be the only, or even the strongest motor predictor of dementia. However, the research in this area has been limited up to this time.
Given that predementia testing is often quite expensive and frequently not covered by insurances, simple and expensive forms of testing and diagnostic evaluations are often welcome. Although this study appears to shed some light on a new diagnosis that may be an important predementia diagnostic, as well as the use of simple and less expensive diagnostic assessments for anticipating future progression to dementia, the new syndrome and its concomitant diagnostics will probably not be fully embraced at this early level. Furthermore, more research will be need to be completed before one can provide greater assurance regarding the validity of this new diagnosis and whether it is truly an important predementia diagnostic that can enhance our ability toward slowing down the progression of dementia.
Furthermore, the study did not appear to address the cause and effect nature of the issue of motor decline as it relates to dementia. Is motor decline a sign of, or even cause, of impeding dementia, or is it a related effect of dementia, albeit incipient stage brain changes that may already be occurring due to the dementia process. Moreover, if a person stays active and maintains a better gait speed, will that reduce the likelihood of dementia? Finally, is MCR a diagnosis that is truly separate from the dementia diagnoses and by creating a new diagnostic category will it be useful for treatment intervention or is it just another label being attached to the elderly person?
Many of the above questions I feel still need to be answered before we enthusiastically embrace a new diagnostic category. For the most part, some of the discovery that motor involvement may be related to dementia is not a great surprise since many forms of dementia will demonstrate motor issues as the disease progresses due to further insult upon brain tissue. I feel that the main question that really is of concern here and that needs to have greater clarification is whether:
- maintaining enhanced gait speed through exercise will reduce the likelihood of future dementia
- whether the diagnosis of MCR will be useful so that successful intervention can be brought about that would ultimately prevent or slow down further neurological disease progression.
Anderson, P. (2014, July). Slow Gait, Cognitive Complaints Predict Cognitive Decline. Medscape, http://www.medscape.com/viewarticle/829135?src=wnl_edit_medn_wir&uac=87637DR&spon=34#1