The effects of cognitive impairment on the multi-scale dynamics of standing postural control during visual-search in older men.

Background: Cognitive impairment disrupts postural control, particularly when standing while performing an unrelated cognitive task (i.e., dual-tasking). The temporal dynamics of standing postural sway are "complex," and such complexity may reflect the capacity of the postural control system to adapt to task demands. We aimed to characterize the impact of cognitive impairment on such sway complexity in older adults. Methods: Forty-nine older adult males (Alzheimer's disease (AD): n = 21; mild cognitive impairment (MCI): n = 13; cognitively-intact: n = 15) completed two 60-s standing trials in each of single-task and visual-search dual-task conditions. In the dual-task condition, participants were instructed to count the frequency of a designated letter in a block of letters projected on screen. The sway complexity of center-of-pressure fluctuations in anterior-posterior (AP) and medial-lateral (ML) direction was quantified using multiscale entropy. The dual-task cost to complexity was obtained by calculating the percent change of complexity from single- to dual-task condition. Results: Repeated-measures ANOVAs revealed significant main effects of group (F > 4.8, p < 0.01) and condition (F = 7.7, p < 0.007) on both AP and ML sway complexity; and significant interaction between group and condition for ML sway complexity (F = 3.7, p = 0.03). The AD group had the lowest dual-task ML complexity, as well as greater dual-task cost to ML (p = 0.03) compared to the other two groups. Visual-search task accuracy was correlated with ML sway complexity in the dual-task condition (r = 0.42, p = 0.007), and the dual-task cost to ML sway complexity (r = 0.39, p = 0.01) across all participants. Conclusion: AD-related cognitive impairment was associated with a greater relative reduction in postural sway complexity from single- to dual-tasking. Sway complexity appears to be sensitive to the impact of cognitive impairment on standing postural control.

Finding dementia in primary care: the results of a clinical demonstration project.

OBJECTIVES: To assess the effect of screening on diagnosing cognitive impairment. DESIGN: Quality improvement initiative. SETTING: Seven Veterans Affairs Medical Centers. PARTICIPANTS: Veterans aged 70 or older without a prior diagnosis of cognitive impairment. MEASUREMENTS: Veterans failing a brief cognitive screen (Mini-Cog score <4/5) at a routine primary care visit were offered a further, comprehensive evaluation with an advance practice registered nurse trained in dementia care and integrated into the primary care clinic. Veterans completing the evaluation were reviewed in a consensus conference and assigned a diagnosis of dementia; cognitive impairment, no dementia; or no cognitive impairment. Total numbers of screens, associated scores (0-5), and the consensus diagnoses were tallied. New cognitive impairment diagnoses were also tracked for veterans who passed the screen but requested further evaluation, failed but declined further evaluation, or were not screened. Primary care provider satisfaction with the program also was assessed. RESULTS: Of 8,342 veterans offered screening, 8,063 (97%) accepted, 2,081 (26%) failed the screen, 580 (28%) agreed to further evaluation, and 540 (93%) were diagnosed with cognitive impairment, including 432 (75%) with dementia. For screen passes requesting further evaluation, 87% (103/118) had cognitive impairment, including 70% (82/118) with dementia. Screen failures declining further evaluation had 17% (259/1,501) incident cognitive impairment diagnosed through standard care, bringing the total newly documented cognitive impairment in all screens to 11% (902/8,063), versus 4% (1,242/28,349) in similar clinics without this program. Eighty-two percent of primary care providers in clinics with this program agreed that it provided a useful service. CONCLUSION: Screening combined with offering further evaluation increased new diagnoses of cognitive impairment in older veterans two to three times. Veterans accepted screening well, and providers found the program useful.