Relationship between Cognitive Performance and Measures of Neurodegeneration among Hispanic and White Non-Hispanic Individuals with Normal Cognition, Mild Cognitive Impairment, and Dementia

Abstract

Objectives: The aim of this study was to determine the presence and severity of potential cultural and language bias in widely used cognitive and other assessment instruments, using structural MRI measures of neurodegeneration as biomarkers of disease stage and severity. Methods: Hispanic (n = 75) and White non-Hispanic (WNH) (n = 90) subjects were classified as cognitively normal (CN), amnestic mild cognitive impairment (aMCI) and mild dementia. Performance on the culture-fair and educationally fair Fuld Object Memory Evaluation (FOME) and Clinical Dementia Rating Scale (CDR) between Hispanics and WNHs was equivalent, in each diagnostic group. Volumetric and visually rated measures of the hippocampus entorhinal cortex, and inferior lateral ventricles (ILV) were measured on structural MRI scans for all subjects. A series of analyses of covariance, controlling for age, depression, and education, were conducted to compare the level of neurodegeneration on these MRI measures between Hispanics and WNHs in each diagnostic group. Results: Among both Hispanics and WNH groups there was a progressive decrease in volume of the hippocampus and entorhinal cortex, and an increase in volume of the ILV (indicating increasing atrophy in the regions surrounding the ILV) from CN to aMCI to mild dementia. For equivalent levels of performance on the FOME and CDR, WNHs had greater levels of neurodegeneration than did Hispanic subjects. Conclusions: Atrophy in medial temporal regions was found to be greater among WNH than Hispanic diagnostic groups, despite the lack of statistical differences in cognitive performance between these two ethnic groups. Presumably, unmeasured factors result in better cognitive performance among WNH than Hispanics for a given level of neurodegeneration.

Differences in Alzheimer’s Disease and Related Dementias Pathology Among African American and Hispanic Women: A Qualitative Literature Review of Biomarker Studies

“…Among the 16 studies that examined neurodegeneration, 2 measured NfL ( Howell et al, 2017 ; Rajan et al, 2020 ), 4 measured total brain volume ( Minagar et al, 2000 ; Brickman et al, 2008 ; DeCarli et al, 2008 ; Aggarwal et al, 2010 ), 8 measured hippocampal and entorhinal volumes ( DeCarli et al, 2008 ; Zahodne et al, 2015 ; Howell et al, 2017 ; Burke et al, 2018 ; Duara et al, 2019 ; Garrett et al, 2019 ; Morris et al, 2019 ; Arruda et al, 2020 ), 4 measured cortical thickness ( Zahodne et al, 2015 ; McDonough, 2017 ; Rizvi et al, 2018 ; Arruda et al, 2020 ), and 4 measured lateral ventricle size ( Minagar et al, 2000 ; Shadlen et al, 2006 ; Brickman et al, 2008 ; Burke et al, 2018 ). Participants in these studies ranged from cognitively normal, MCI, and AD and were recruited from both ADRC and community settings.…”

“…This group additionally reported that Hispanic race was associated with 0.12 mm 3 greater hippocampal volume and 0.13 mm 3 greater entorhinal volume independent of age, gender, functional activities questionnaire score, and MoCA score. In another ADRC-based study of 165 participants with normal cognition, MCI, and dementia, Hispanics showed greater hippocampal and entorhinal volumes relative to nHW after adjusting for age, depression, and Geriatric Depression Scale score ( Burke et al, 2018 ).…”

“…In the WHICAP cohort across 702 participants with normal cognition and MCI, compared to being nHW, AA and Hispanic race was associated with smaller lateral ventricle volumes independent of age, sex, and vascular disease history (Brickman et al, 2008). Additionally, in an ADRC-based study of 165 participants, Hispanics exhibited left and right ventricle volumes that were smaller in cognitively normal, MCI, and dementia participants, compared to nHW participants with corresponding diagnoses (Burke et al, 2018); this was after adjustment for age, education, and Geriatric Depression Scale score. Similarly, Minagar et al (2000) reported in a study with 144 Hispanics and nHW diagnosed with AD that ventricular size was smaller in Hispanics relative to nHW after covariate adjustment.…”

Origins Matter: Culture Impacts Cognitive Testing in Parkinson’s Disease

“…In terms of prognostication, different patterns of cognitive performance may predict eventual conversion to dementia in different ethnic/racial groups (Weissberger et al, 2013). As for biomarkers, a pertinent example is that the correspondence between the degree of MTL atrophy in MCI and the magnitude of cognitive dysfunction on testing varies across race/ethnicity despite controlling for various risk factors (DeCarli et al, 2008; Burke et al, 2018; Weissberger et al, 2019). It is reasonable to assume that cultural bias on testing has a similar impact on MCI and dementia in PD.…”

Medial temporal lobe atrophy and posterior atrophy scales normative values

“…Atrophy of the medial temporal and parietal lobe is thus common, although not specific, of AD. Volumetric studies of these areas show a 10% volume decrease in patients with mild cognitive impairment (MCI) due to AD (Chan et al, 2003; Frisoni et al, 2009) and a correlation of these volumes with the severity of cognitive impairment (Burke et al, 2018). Consistently, hippocampal atrophy and parietal atrophy are significant predictors of progression from MCI to dementia, most frequently due to AD (DeCarli et al, 2007; Jack et al, 1999; Da et al, 2013; Pyun et al, 2017; Yao et al, 2012).…”