| Background: Researchers have not been able to develop a cohesive profile of cognitive functioning in older adults. Older adults may develop a variety of cognitive deficits that may or may not lead to significant dysfunction. As the population of adults 65 and older continues to increase in the United States, it has provided a novel opportunity to better understand cognition in this unique group. Population growth in older adults has resulted in an increase in dementia and other cognitive disorders. This has prompted a vast focus on early identification of cognitive dysfunction. There has been a general consensus among researchers that a transitional period between normal aging and dementia exists, and that this period may represent the earliest sign of a neurodegenerative process. One term used to refer to this transitional period is Mild Cognitive Impairment (MCI), a heterogeneous condition with various etiologies and presentations. Objectives: Various patterns of cognitive dysfunction in an older adult population were studied. First, this study attempted to differentiate between cognitive profiles of aging through use of the Montreal Cognitive Screening Assessment (MoCA), which assesses various cognitive domains. Second, this study investigated performance patterns on various MoCA tasks in older adults with different cognitive profiles. Finally, the study set out to determine the relationship between older adults' performance on brief screening tasks compared to similar comprehensive tests. To my knowledge, this is the first study that attempts to ascertain the various presentations of MCI through the use of a single neuropsychological screening test. Methods: This study used an archival dataset that included 102 older adults (62 women, 40 men, Mage = 77.74, SD=6.54; range: 63-91). Regarding racial and ethnic identity, the distribution of participants is 91% Caucasian, 6% Hispanic or Latino, 0.9% African American, 0.9% Asian American, and 0.9% Native American. The mean education level was M = 15.75 (SD = 2.05). Participants were administered the MoCA test and a comprehensive neuropsychological battery which allowed them to be assigned to a cognitive status group (i.e., healthy=60, amnestic MCI=5, non-amnestic MCI=18, multiple domain MCI=11, and dementia=8). Results: The MoCA composite score was not useful in distinguishing MCI subtypes, but clearly distinguished healthy cognition from dementia in a highly educated population. Compared to individuals diagnosed with amnestic MCI, those with multiple-domain MCI were 10.6 times more likely to make errors in multiple domains and those with dementia were 28 times more likely to make errors across multiple domains. Those diagnosed with non-amnestic MCI had significantly poorer performances on the visuospatial/executive domain compared to healthy agers and those with amnestic MCI. Passing performances on the naming and letter fluency tasks were significantly associated with passing performances on comparable comprehensive tests. KEY WORDS: aging, cognitive decline, dementia, MCI, neuropsychological screening. |
