John Brockington

Medical decision-making capacity in patients with mild cognitive impairment

Objectives: To empirically assess the capacity of patients with amnestic mild cognitive impairment (MCI) to consent to medical treatment under different consent standards (Ss). Methods: Participants were 56 healthy controls, 60 patients with MCI, and 31 patients with mild Alzheimer disease (AD). Each participant was administered the Capacity to Consent to Treatment Instrument (CCTI) and a comprehensive neuropsychological battery. Group differences in performance on the CCTI and neuropsychological variables were examined. In addition, the capacity status (capable, marginally capable, or incapable) of each MCI participant on each CCTI standard was examined using cut scores derived from control performance. Results: Patients with MCI performed comparably to controls on minimal consent standards requiring merely expressing a treatment choice (S1) or making the reasonable treatment choice [S2], but significantly below controls on the three clinically relevant standards of appreciation (S3), reasoning (S4), and understanding (S5). In turn, the MCI group performed significantly better than the mild AD group on [S2], S4, and S5. Regarding capacity status, patients with MCI showed a progressive pattern of capacity compromise (marginally capable and incapable outcomes) related to stringency of consent standard. Conclusions: Patients with amnestic mild cognitive impairment (MCI) demonstrate significant impairments on clinically relevant abilities associated with capacity to consent to treatment. In obtaining informed consent, clinicians and researchers working with patients with MCI must consider the likelihood that many of these patients may have impairments in consent capacity related to their amnestic disorder and related cognitive impairments. GLOSSARY: AD = Alzheimer disease; ADRC = Alzheimers Disease Research Center; CCTI = Capacity to Consent to Treatment Instrument; CVLT-II = California Verbal Learning Test, second edition; DRS-2 = Dementia Rating Scale, 2nd edition; GDS = Geriatric Depression Scale; MCI = mild cognitive impairment; MDC = medical decision-making capacity; MMSE = Mini-Mental State Examination; Ss = consent standards; WAIS-III = Wechsler Adult Intelligence Scale, third edition; WMS-III = Wechsler Memory Scale, third edition; WMS-R = Wechsler Memory Scale, revised edition; WRAT-3 = Wide Range Achievement Test, third edition.

Declining financial capacity in mild cognitive impairment A 1-year longitudinal study

Objective: To investigate 1-year change in financial capacity in relation to conversion from amnestic mild cognitive impairment (MCI) to dementia. Methods: Seventy-six cognitively healthy older controls, 25 patients with amnestic MCI who converted to Alzheimer-type dementia during the study period (MCI converters), and 62 patients with MCI who did not convert to dementia (MCI nonconverters) were administered the Financial Capacity Instrument (FCI) at baseline and 1-year follow-up. Performance on the FCI domain and global scores was compared within and between groups using multivariate repeated-measures analyses. Results: At baseline, controls performed better than MCI converters and nonconverters on almost all FCI domains and on both FCI total scores. MCI converters performed below nonconverters on domains of financial concepts, cash transactions, bank statement management, and bill payment and on both FCI total scores. At 1-year follow-up, MCI converters showed significantly greater decline than controls and MCI nonconverters for the domain of checkbook management and for both FCI total scores. The domain of bank statement management showed a strong trend. For both the checkbook and bank statement domains, MCI converters showed declines in procedural skills, such as calculating the correct balance in a checkbook register, but not in conceptual understanding of a checkbook or a bank statement. Conclusions: Declining financial skills are detectable in patients with mild cognitive impairment (MCI) in the year before their conversion to Alzheimer disease. Clinicians should proactively monitor patients with MCI for declining financial skills and advise patients and families about appropriate interventions.

Amnestic mild cognitive impairment: diagnostic outcomes and clinical prediction over a two-year time period.

Amnestic mild cognitive impairment (MCI) has been defined as a precursor to Alzheimers disease (AD), although it is sometimes difficult to identify which persons with MCI will eventually convert to AD. We sought to predict MCI conversion to AD over a two-year follow-up period using baseline demographic and neuropsychological test data from 49 MCI patients. Using a stepwise discriminant function analysis with Dementia Rating Scale (DRS) Initiation/Perseveration and Wechsler Memory Scale, third edition (WMS-III) Visual Reproduction Percent Retention scores, we correctly classified 85.7% of the sample as either AD converters or MCI nonconverters, with 76.9% sensitivity and 88.9% specificity. Adding race, the presence of vascular risk factors, or cholinesterase inhibitor use to the analysis did not greatly change the classification rates obtained with neuropsychological test data. Examining neuropsychological test cutoff scores revealed that DRS Initiation/Perseveration scores below 37 and Visual Reproduction Percent Retention scores below 26% correctly identified AD converters with 76.9% sensitivity and 91.7% specificity. These results demonstrate that commonly administered neuropsychological tests identify persons with MCI at baseline who are at risk for conversion to AD within 1-2 years. Such methods could aid in identifying MCI patients who might benefit from early treatment, in providing prognostic information to patients, and identifying potential clinical trial participants.

Neurocognitive predictors of financial capacity across the dementia spectrum: Normal aging, mild cognitive impairment, and Alzheimer’s disease

Financial capacity is a complex instrumental activity of daily living critical to independent functioning of older adults and sensitive to impairment in patients with amnestic mild cognitive impairment (MCI) and Alzheimers disease (AD). However, little is known about the neurocognitive basis of financial impairment in dementia. We developed cognitive models of financial capacity in cognitively healthy older adults (n = 85) and patients with MCI (n = 113) and mild AD (n = 43). All participants were administered the Financial Capacity Instrument (FCI) and a neuropsychological test battery. Univariate correlation and multiple regression procedures were used to develop cognitive models of overall FCI performance across groups. The control model (R2 = .38) comprised (in order of entry) written arithmetic skills, delayed story recall, and simple visuomotor sequencing. The MCI model (R2 = .69) comprised written arithmetic skills, visuomotor sequencing and set alternation, and race. The AD model (R2 = .65) comprised written arithmetic skills, simple visuomotor sequencing, and immediate story recall. Written arithmetic skills (WRAT-3 Arithmetic) was the primary predictor across models, accounting for 27% (control model), 46% (AD model), and 55% (MCI model) of variance. Executive function and verbal memory were secondary model predictors. The results offer insight into the cognitive basis of financial capacity across the dementia spectrum of cognitive aging, MCI, and AD.

Medical decision-making capacity in mild cognitive impairment A 3-year longitudinal study

Objective: To investigate longitudinal change in the medical decision-making capacity (MDC) of patients with amnestic mild cognitive impairment (MCI) under different consent standards. Methods: Eighty-eight healthy older controls and 116 patients with MCI were administered the Capacity to Consent to Treatment Instrument at baseline and at 1 to 3 (mean = 1.7) annual follow-up visits thereafter. Covariate-adjusted random coefficient regressions were used to examine differences in MDC trajectories across MCI and control participants, as well as to investigate the impact of conversion to Alzheimer disease on MCI patients’ MDC trajectories. Results: At baseline, MCI patients performed significantly below controls only on the three clinically relevant standards of appreciation, reasoning, and understanding. Compared with controls, MCI patients experienced significant declines over time on understanding but not on any other consent standard. Conversion affected both the elevation (a decrease in performance) and slope (acceleration in subsequent rate of decline) of MCI patients’ MDC trajectories on understanding. A trend emerged for conversion to be associated with a performance decrease on reasoning in the MCI group. Conclusions: Medical decision-making capacity (MDC) decline in mild cognitive impairment (MCI) is a relatively slow but detectable process. Over a 3-year period, patients with amnestic MCI show progressive decline in the ability to understand consent information. This decline accelerates after conversion to Alzheimer disease (AD), reflecting increasing vulnerability to decisional impairment. Clinicians and researchers working with MCI patients should give particular attention to the informed consent process when conversion to AD is suspected or confirmed.

Cognitive models of medical decision-making capacity in patients with mild cognitive impairment.

This study investigated cognitive predictors of medical decision-making capacity (MDC) in patients with amnestic mild cognitive impairment (MCI). A total of 56 healthy controls, 60 patients with MCI, and 31 patients with mild Alzheimers disease (AD) were administered the Capacity to Consent to Treatment Instrument (CCTI) and a neuropsychological test battery. The CCTI assesses MDC across four established treatment consent standards--S1 (expressing choice), S3 (appreciation), S4 (reasoning), and S5 (understanding)--and one experimental standard [S2] (reasonable choice). Scores on neuropsychological measures were correlated with scores on each CCTI standard. Significant bivariate correlates were subsequently entered into stepwise regression analyses to identity group-specific multivariable predictors of MDC across CCTI standards. Different multivariable cognitive models emerged across groups and consent standards. For the MCI group, measures of short-term verbal memory were key predictors of MDC for each of the three clinically relevant standards (S3, S4, and S5). Secondary predictors were measures of executive function. In contrast, in the mild AD group, measures tapping executive function and processing speed were primary predictors of S3, S4, and S5. MDC in patients with MCI is supported primarily by short-term verbal memory. The findings demonstrate the impact of amnestic deficits on MDC in patients with MCI.

Magnetic Resonance Imaging Volume of the Angular Gyri Predicts Financial Skill Deficits in People with Amnestic Mild Cognitive Impairment

OBJECTIVES: To better understand how brain atrophy in amnestic mild cognitive impairment (MCI) as measured using magnetic resonance imaging (MRI) volumetrics could affect instrumental activities of daily living (IADLs) such as financial abilities.

MRI volume of the medial frontal cortex predicts financial capacity in patients with mild Alzheimer’s disease

Persons with mild Alzheimer’s disease (AD) have significant deficits in financial abilities. This study examined the relationship between brain structure volumes, cognition, and financial capacity in patients with mild AD. Sixteen mild AD patients and 16 older adult comparisons completed the Financial Capacity Instrument (FCI), a psychometric measure of financial abilities, and also underwent magnetic resonance imaging (MRI) to obtain volumes of the bilateral hippocampi, angular gyri, precunei, and medial and dorsolateral frontal cortices. Mild AD patients performed significantly below comparisons on the FCI and had significantly smaller hippocampi. Among mild AD patients, FCI performance was moderately correlated with frontal (medial and dorsolateral frontal cortex) and posterior (angular gyri and precunei) cortical volumes. Stepwise regression demonstrated that medial frontal cortex volume predicted FCI score. The relationship between medial frontal cortex volume and overall FCI score was partially mediated by two measures of simple attention (DRS Attention, DRS Construction). The findings suggest that medial frontal cortex atrophy and associated declines in simple attention play an increasingly important role in declining financial skills in patients with mild AD.

Lower hippocampal volume predicts decrements in lane control among drivers with amnestic mild cognitive impairment

Objectives: There are few methods to discern driving risks in patients with early dementia and mild cognitive impairment (MCI). We aimed to determine whether structural magnetic resonance imaging (MRI) of the hippocampus—a biomarker of probable Alzheimer pathology and a measure of disease severity in those affected—is linked to objective ratings of on-road driving performance in older adults with and without amnestic MCI. Methods: In all, 49 consensus-diagnosed participants from an Alzheimer’s Disease Research Center (15 diagnosed with amnestic MCI and 34 demographically similar controls) underwent structural MRI and on-road driving assessments. Results: Mild atrophy of the left hippocampus was associated with less-than-optimal ratings in lane control but not with other discrete driving skills. Decrements in left hippocampal volume conferred higher risk for less-than-optimal lane control ratings in the patients with MCI (B = −1.63, standard error [SE] = .74, Wald = 4.85, P = .028), but not in controls (B = 0.13, SE = .415, Wald = 0.10, P = .752). The odds ratio and 95% confidence interval for below-optimal lane control in the MCI group was 4.41 (1.18-16.36), which was attenuated to 3.46 (0.88-13.60) after accounting for the contribution of left hippocampal volume. Conclusion: These findings suggest that there may be a link between hippocampal atrophy and difficulties with lane control in persons with amnestic MCI. Further study appears warranted to better discern patterns of brain atrophy in MCI and Alzheimer disease and whether these could be early markers of clinically meaningful driving risk.

Executive function is associated with brain proton magnetic resonance spectroscopy in amnestic mild cognitive impairment.

Persons with amnestic mild cognitive impairment (MCI) show deficits on executive function measures, although the neuroanatomic basis of executive function in MCI is unknown. We investigated cognitive correlates of 3-tesla proton magnetic resonance spectroscopy (MRS) of the posterior cingulate gyrus in 26 MCI patients. Posterior cingulate ratio of myo-inositol to creatine (mI/Cr) was negatively correlated (−.51) with spontaneous clock drawing. This relationship was not attenuated after accounting for age, overall cognitive function, or memory performance. This finding suggests a role for the posterior cingulate in executive function in MCI. Proton MRS may offer a means to track neurometabolic changes associated with cognitive impairment in MCI.