Introduction: Our objective was to examine the association between perseverations produced on the semantic verbal fluency (SVF) task in asymptomatic individuals and the future diagnosis of cognitive impairment (CI). Method: Participants were individuals participating in the Mayo Clinic Study of Aging (N = 1269, Mage = 79.3 years, SD = 5.1; 51% men). All were cognitively normal at baseline and were followed in 15-month intervals for up to 6 visits. Each neurocognitive assessment included SVF tasks (“animals,” “fruits,” and “vegetables”). Cox modeling was used to test for associations between perseverations and time to CI diagnosis. Results: Perseverations on the “animals” SVF task were associated with incident CI (hazard ratio = 1.35; 95% confidence interval, CI [1.10, 1.66]). No significant association was found with perseverations on the “fruits” or “vegetables” SVF tasks. Mixed-effects modeling in cognitively normal participants revealed that the number of perseverations at baseline is significantly associated with decline in memory and visuospatial cognitive domains but is not associated with decline in attention. Conclusions: Assessing perseverations together with standard SVF scores on the “animals” SVF task can help in early identification of asymptomatic individuals at an increased risk for CI. Perseverations are not associated with attention, but rather visual and verbal working memory mechanisms. In longitudinal settings aimed at early detection of signs of CI in presymptomatic individuals, SVF testing with scoring that includes counting of perseverations may potentially serve as a practical alternative to the more cumbersome memory tests.
|Original language||English (US)|
|Number of pages||9|
|Journal||Journal of Clinical and Experimental Neuropsychology|
|State||Published - Sep 14 2018|
Bibliographical noteFunding Information:
This work was supported by the Alzheimer?s Association [grant number DNCFI-12-242985]; National Institutes of Health, National Institute on Aging [grant number P50 AG16574], [grant number U01 AG06786]. We would like to thank Jennifer Strommen, Benjamin Eischens, Mara Anderson, the University of Minnesota students who worked on digitizing thousands of hand-written SVF tests, and James Ryan and Thomas Christie who worked on programming. We also would like to thank Dana Swenson-Dravis and Dorla Burton for extracting and collating psychometric information at the Mayo Clinic for the Alzheimer's Disease Research Center and Mayo Clinic Study of Aging (MCSA) study participants. Last but not least, we extend special thanks to the study participants, their families, and caregivers.
This work was supported by the Alzheimer’s Association [grant number DNCFI-12-242985]; National Institutes of Health, National Institute on Aging [grant number P50 AG16574], [grant number U01 AG06786].
- Alzheimer’s disease
- cognitive impairment
- verbal fluency