Assessing Longitudinal Cognitive Change in Mild Cognitive Impairment Using Estimated Standardized Regression-Based Formulas.

BACKGROUND: Cognitive change in mild cognitive impairment (MCI), a likely prodrome to Alzheimer's disease, can be tracked with repeated neuropsychological assessments, but there has been little work quantifying these changes over time. Cognitive change can be statistically examined using standardized regression-based (SRB) formulas, which yield a z-score indicating amount of change compared to a normative group. OBJECTIVE: To use SRB z-scores to quantify cognitive change in a sample of patients classified as MCI at baseline, and to compare cognitive change in those who remained MCI on follow-up (MCI-Stable) and those who progressed to dementia (MCI-Decline). METHODS: Using 283 MCI patients from a cognitive disorders clinic who were re-assessed after approximately one- and one-half years, SRB z-scores were calculated for each test in a comprehensive neuropsychological battery for each participant. RESULTS: There was a significant decline between timepoints across all cognitive tests, with the greatest amount of decline on tests of learning and memory. Group differences were seen on nearly all cognitive tests, with the MCI-Decline group showing more decline (i.e., significantly larger and negative z-scores) than the MCI-Stable participants. Notable cognitive decline was also observed in the MCI-Stable group, with z-scores ranging from -0.01 - -2.24 compared to normative data. CONCLUSION: This study highlights the amount of cognitive decline that occurs in MCI, including for those who remain "stable" and those who progress to dementia. It also demonstrates the value of the SRB method in more clearly quantifying cognitive decline, which may help identify individuals most vulnerable to MCI progression.

Comparison shopping: Is neuropsychological evaluation more expensive than neuroimaging?

OBJECTIVE: This study empirically examined if neuropsychological evaluation (NPE) is expensive compared to other diagnostic procedures such as neuroimaging. METHOD: We aggregated data on charges for NPE and common neuroimaging procedures (e.g., head CT and brain MRI) from hospitals in the U.S. Charges for five-hour NPE and eight-hour NPE were compared to charges for head CT and brain MRI, respectively. Difference scores were calculated between five-hour NPE and head CT and between eight-hour NPE and brain MRI. A charge difference of $250 or less was considered minimal. NPE and neuroimaging charges were compared across U.S. regions. RESULTS: Median head CT charges were $1942 to $2699. Median brain MRI charges were $3103 to $4487. Median five-hour NPE charges were $1855 to $1977. Median eight-hour NPE charges were $2757 to $2917. Head CT and five-hour NPE charges were not significantly different. Eight-hour NPE and brain MRI charges were not significantly different. Charge differences between five-hour NPE and head CT were minimal in 32.3% of hospitals. Charge differences between eight-hour NPE and brain MRI were minimal in 21.2% of hospitals. U.S. regions were not significantly different in charges for NPE or neuroimaging. CONCLUSIONS: Findings provide preliminary data on charges for NPE in relation to charges for common imaging procedures. NPE does not appear to be more expensive than neuroimaging and, in fact, appears comparable. Future research might expand the information on NPE charges to include additional settings.

Branching Condition of the Color-Word Interference Test Enhances Prediction of Meta-Tasking in Community-Dwelling Older Adults.

OBJECTIVES: Meta-tasking (MT) is an aspect of executive functioning (EF) that involves the ability to branch (i.e., to apply "if-then" rules) and to effectively interleave sub-goals of one task with sub-goals of another task. As such, MT is crucial for successful planning, coordination, and execution of multiple complex tasks in daily life. Traditional tests of EF fail to adequately measure MT. This study examined whether Condition 4 of the Color-Word Interference Test (CWIT-4; the inhibition/switching condition that requires branching) predicted MT beyond Condition 3 (CWIT-3; inhibition-only condition) and beyond other subtests from the Delis-Kaplan Executive Function System (D-KEFS) that have a switching condition. METHOD: Ninety-eight non-Hispanic white community-dwelling older adults completed the first four subtests of the D-KEFS and an ecologically valid measure of MT. RESULTS: Time to completion and total errors on CWIT-4 accounted for variance in MT above and beyond CWIT-3 and beyond the switching conditions of other D-KEFS subtests. Results remained virtually unchanged when controlling for demographics and general cognitive status. CONCLUSIONS: Among older adults, CWIT-4 is more strongly associated with MT than other D-KFES tasks. Future research should examine whether CWIT-4 relates to lapses in instrumental activities of daily living among older adults above and beyond other EF tests.

Depressive symptoms precede cognitive impairment in de novo Parkinson's disease patients: Analysis of the PPMI cohort.

INTRODUCTION: Nonmotor symptoms, including depression, anxiety, apathy, and cognitive dysfunction, are common in Parkinson's disease (PD). Although a link between mood symptoms and cognitive impairment in PD has been theorized vis-à-vis striatal dopamine depletion, studies have been inconsistent regarding the relationship between mood symptoms and cognitive function. Inconsistencies may reflect the cross-sectional nature of previous studies. The current study examined the bidirectional longitudinal relationship between mood and cognition. METHOD: Data were obtained from 310 individuals newly diagnosed with PD, who were followed up to 4 years (baseline, 1st, 2nd, 3rd, and 4th annual follow-ups). Apathy, anxiety, depressive symptoms, motor severity, and neurocognitive functioning were assessed at each annual assessment. The longitudinal relationship between apathy, anxiety, depressive symptoms, and cognition was analyzed with multilevel models. RESULTS: Over the 4-year period, more severe depressive symptoms were related to worse performance on tasks of processing speed, verbal learning, and verbal delayed recall. Additionally, there was a significant Depression × Time interaction, suggesting that individuals with more severe depressive symptoms experience more rapid declines in global cognitive functioning and verbal learning. Apathy and anxiety were not significantly related to performance in any cognitive test. Lagged models revealed that changes in depression precede declines in working memory, verbal learning, delayed verbal recall, and global cognition. CONCLUSION: Findings suggest depressive symptoms may be a harbinger for future cognitive decline among individuals with PD. (PsycINFO Database Record (c) 2019 APA, all rights reserved).