A decline in gait speed paired with domain-specific cognitive decline proved to be strongly correlated with subsequent development of dementia over a six-year period.
Level of Evidence Rating: 2 (Good)
Study Rundown: Dementia is an increasingly common and poorly understood neurocognitive disease associated with significant slowing of mental and physical functioning. The present study sought to assess changes in gait speed and changes in cognitive function over time in order to understand the degree of accuracy with which physical slowing mirrors and predicts mental slowing in dementia patients. Data from a total of 15,309 participants were collected and analyzed in this study; mean age at study enrolment was 75.0 years and participants were followed for a median time of 4.5 years. Patients with dual gait decline and cognitive decline were found to be at a significantly higher risk of developing dementia compared with those who did not decline in either domain, and than those who declined in either gait or cognition alone. This was true in all four domains of cognition assessed (memory, global cognitive function, processing speed, verbal fluency). This study by Collyer et al retrospectively analyzed a large cohort of seniors and determined that a decline in both cognitive function and gait over time is predictive of a dementia diagnosis. In a practical sense, this work suggests that screening for gait speed and cognition in elderly patients may lead to earlier detection of dementia and possibly earlier initiation of therapy. Strengths of this study include the large sample size and the magnitude of the effect size. A major limitation of this work is that the participants were considered healthier than average elderly patients in the general population due to strict eligibility criteria for the trial, which limits the external validity of these findings.