Neuropsychological Test Norms in Cognitively Intact Oldest-Old

Abstract

Objectives: Individuals aged 90 or older (oldest-old), the fastest growing segment of the population, are at increased risk of developing cognitive impairment compared with younger old. Neuropsychological evaluation of the oldest-old is important yet challenging in part because of the scarcity of test norms for this group. We provide neuropsychological test norms for cognitively intact oldest-old.

Methods: Test norms were derived from 403 cognitively intact participants of The 90+ Study, an ongoing study of aging and dementia in the oldest-old. Cognitive status of intact oldest-old was determined at baseline using cross-sectional approach. Individuals with cognitive impairment no dementia or dementia (according to DSM-IV criteria) were excluded. Participants ranged in age from 90 to 102 years (mean=94). The neuropsychological battery included 11 tests (Mini-Mental Status Examination, Modified Mini-Mental State Examination, Boston Naming Test - Short Form, Letter Fluency Test, Animal Fluency Test, California Verbal Learning Test-II Short Form, Trail Making Tests A/B/C, Digit Span Forward and Backwards Test, Clock Drawing Test, CERAD Construction Subtests), and the Geriatric Depression Scale.

Results: Data show significantly lower scores with increasing age on most tests. Education level, sex, and symptoms of depression were associated with performance on several tests after accounting for age.

Conclusions: Provided test norms will help to distinguish cognitively intact oldest-old from those with cognitive impairment. (JINS, 2019, 25, 530-545).

Keywords: 80 and over; Aged; Cognition; Geriatric assessment; Neuropsychology; Reference values.

Figure 1.

Flowchart of Participant Inclusion LWCS – Leisure World Cohort Study. All percentages are calculated from the total 90+ Study cohort (N=1,802)