Impairment of medical decisional capacity in relation to Karnofsky Performance Status in adults with malignant brain tumor

BACKGROUND

We aimed to investigate the relationship between medical decisional capacity (MDC) and Karnofsky Performance Status (KPS) in adults with malignant brain tumors.

METHODS

Participants were 71 adults with primary (n = 26) or metastatic (n = 45) brain tumors. Testing to determine KPS scores and MDC was performed as close together as possible for each patient. Participants were administered a standardized measure of medical decision-making capacity (Capacity to Consent to Treatment Instrument [CCTI]) to assess 3 treatment consent abilities (ie, appreciation, reasoning, and understanding). Capacity classifications (ie, capable, marginally capable, and incapable) were established using cut scores previously derived from healthy control CCTI performance.

RESULTS

The majority of participants had KPS scores of 90-100 (n = 39), with the remainder divided between KPS scores of 70-80 (n = 26) and 50-60 (n = 6). Comparisons between persons with KPS scores of 90-100 or 70-80 revealed significant differences on the CCTI consent standards of understanding and appreciation. Participants with KPS ratings of 90-100 achieved 46% capable classifications across all CCTI standards, in contrast with 23% of participants with KPS ratings of 70-80, and 0% of participants with KPS ratings of 50-60.

CONCLUSIONS

A substantial portion of brain-tumor patients with KPS scores reflecting only minimal disability nonetheless demonstrated impairments on standardized measures of MDC. Clinicians working with this adult population should carefully screen for capacity to make clinical treatment decisions regardless of functional/performance status.

Rarity of the Alzheimer disease-protective APP A673T variant in the United States

IMPORTANCE

Recently, a rare variant in the amyloid precursor protein gene (APP) was described in a population from Iceland. This variant, in which alanine is replaced by threonine at position 673 (A673T), appears to protect against late-onset Alzheimer disease (AD). We evaluated the frequency of this variant in AD cases and cognitively normal controls to determine whether this variant will significantly contribute to risk assessment in individuals in the United States.

OBJECTIVE

To determine the frequency of the APP A673T variant in a large group of elderly cognitively normal controls and AD cases from the United States and in 2 case-control cohorts from Sweden.

DESIGN, SETTING, AND PARTICIPANTS

Case-control association analysis of variant APP A673T in US and Swedish white individuals comparing AD cases with cognitively intact elderly controls. Participants were ascertained at multiple university-associated medical centers and clinics across the United States and Sweden by study-specific sampling methods. They were from case-control studies, community-based prospective cohort studies, and studies that ascertained multiplex families from multiple sources.

MAIN OUTCOMES AND MEASURES

Genotypes for the APP A673T variant were determined using the Infinium HumanExome V1 Beadchip (Illumina, Inc) and by TaqMan genotyping (Life Technologies).

RESULTS

The A673T variant genotypes were evaluated in 8943 US AD cases, 10 480 US cognitively normal controls, 862 Swedish AD cases, and 707 Swedish cognitively normal controls. We identified 3 US individuals heterozygous for A673T, including 1 AD case (age at onset, 89 years) and 2 controls (age at last examination, 82 and 77 years). The remaining US samples were homozygous for the alanine (A673) allele. In the Swedish samples, 3 controls were heterozygous for A673T and all AD cases were homozygous for the A673 allele. We also genotyped a US family previously reported to harbor the A673T variant and found a mother-daughter pair, both cognitively normal at ages 72 and 84 years, respectively, who were both heterozygous for A673T; however, all individuals with AD in the family were homozygous for A673.

CONCLUSIONS AND RELEVANCE

The A673T variant is extremely rare in US cohorts and does not play a substantial role in risk for AD in this population. This variant may be primarily restricted to Icelandic and Scandinavian populations.

Cognitive predictors of understanding treatment decisions in patients with newly diagnosed brain metastasis

BACKGROUND

Medical decision-making capacity is a higher-order functional skill that refers to a patient's ability to make informed, sound decisions related to care and treatment. In a medical context, understanding is the most cognitively demanding consent standard and refers to a patient's ability to comprehend information to the extent that informed decisions can be made.

METHODS

The association between reasoning and cognition was examined using data from 41 patients with diagnosed brain metastasis. All diagnoses were made by a board-certified radiation oncologist and were verified histologically. In total, 41 demographically matched, cognitively healthy controls were also included to aid in classifying patients with brain metastasis according to reasoning status (ie, intact or impaired).

RESULTS

Results indicate that measures of simple attention, verbal fluency, verbal memory, processing speed, and executive functioning were all associated with understanding, and that verbal memory and phonemic fluency were the primary cognitive predictors. Using these two primary predictors, equations can be constructed to predict the ability to understand treatment decisions in patients with brain metastasis.

CONCLUSIONS

Although preliminary, these data demonstrate how cognitive measures can estimate understanding as it relates to medical decision-making capacities in these patients. Clinically, these findings suggest that poor verbal memory and expressive language function could serve as "red flags" for reduced consent capacity in this patient population, thus signaling that a more comprehensive medical decision-making capacity evaluation is warranted.

Cognition in patients with newly diagnosed brain metastasis: profiles and implications

Cognitive impairment is a common symptom in patients with brain metastasis, and significant cognitive dysfunction is prevalent in a majority of patients who are still able to engage in basic self-care activities. In the current study, the neurocognitive performance of 32 patients with brain metastasis and 32 demographically-matched controls was examined using a battery of standardized neuropsychological tests, with the goal of comprehensively examining the cognitive functioning of newly diagnosed brain metastasis patients. The cognition of all patients was assessed within 1 week of beginning treatment for brain metastasis. Results indicated impairments in verbal memory, attention, executive functioning, and language in relation to healthy controls. Performance in relation to appropriate normative groups was also examined. Overall, cognitive deficits were prevalent and memory was the most common impairment. Given that cognitive dysfunction was present in this cohort of patients with largely minimal functional impairment, these results have implications for patients, caregivers and health care providers treating patients with brain metastasis.

Recovery over 6 months of medical decision-making capacity after traumatic brain injury

OBJECTIVE

To investigate recovery of medical decision-making capacity (MDC) over 6 months in persons with traumatic brain injury (TBI) stratified by injury severity.

DESIGN

Longitudinal study comparing controls and patients with TBI 1 month after injury (t1) and 6 months after injury (t2).

SETTING

Inpatient TBI rehabilitation unit and outpatient neurology department.

PARTICIPANTS

Participants (N=151) consisted of control subjects (n=60) and patients with TBI (n=91) stratified by injury severity: mild TBI (mTBI; n=27), complicated mild TBI (cmTBI; n=20), and moderate/severe TBI (msevTBI; n=44).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

We used the Capacity to Consent to Treatment Instrument to evaluate MDC performance on 5 consent standards (expressing choice, reasonable choice, appreciation, reasoning, and understanding). We also assigned capacity impairment ratings on the consent standards to each participant with TBI using cut scores referenced to control performance.

RESULTS

Control performance was stable across time on the consent standards. Patients with mTBI and cmTBI performed below controls on the understanding standard at t1 but not t2. Patients with msevTBI performed below controls on appreciation, reasoning, and understanding at t1, and on appreciation and understanding at t2, but showed substantial improvement over time.

CONCLUSIONS

Regardless of injury severity, all groups with TBI demonstrated baseline impairment of MDC with subsequent partial or full recovery of MDC over a 6-month period. However, a sizeable proportion of individual patients with TBI in each group continued to demonstrate capacity compromise at 6 months postinjury. Clinically, this finding suggests that individuals with TBI, regardless of injury severity, need continued monitoring regarding MDC for at least 6 months after injury.

Latent information in fluency lists predicts functional decline in persons at risk for Alzheimer disease

OBJECTIVE

We constructed random forest classifiers employing either the traditional method of scoring semantic fluency word lists or new methods. These classifiers were then compared in terms of their ability to diagnose Alzheimer disease (AD) or to prognosticate among individuals along the continuum from cognitively normal (CN) through mild cognitive impairment (MCI) to AD.

METHOD

Semantic fluency lists from 44 cognitively normal elderly individuals, 80 MCI patients, and 41 AD patients were transcribed into electronic text files and scored by four methods: traditional raw scores, clustering and switching scores, "generalized" versions of clustering and switching, and a method based on independent components analysis (ICA). Random forest classifiers based on raw scores were compared to "augmented" classifiers that incorporated newer scoring methods. Outcome variables included AD diagnosis at baseline, MCI conversion, increase in Clinical Dementia Rating-Sum of Boxes (CDR-SOB) score, or decrease in Financial Capacity Instrument (FCI) score. Receiver operating characteristic (ROC) curves were constructed for each classifier and the area under the curve (AUC) was calculated. We compared AUC between raw and augmented classifiers using Delong's test and assessed validity and reliability of the augmented classifier.

RESULTS

Augmented classifiers outperformed classifiers based on raw scores for the outcome measures AD diagnosis (AUC .97 vs. .95), MCI conversion (AUC .91 vs. .77), CDR-SOB increase (AUC .90 vs. .79), and FCI decrease (AUC .89 vs. .72). Measures of validity and stability over time support the use of the method.

CONCLUSION

Latent information in semantic fluency word lists is useful for predicting cognitive and functional decline among elderly individuals at increased risk for developing AD. Modern machine learning methods may incorporate latent information to enhance the diagnostic value of semantic fluency raw scores. These methods could yield information valuable for patient care and clinical trial design with a relatively small investment of time and money.

Assessment of capacity in an aging society

Over the past 40 years, the assessment and scientific study of capacity in older adults has emerged as a distinct field of clinical and research activity for psychologists. This new field reflects the convergence of several trends: the aging of American society, the growing incidence and prevalence of dementia, and the patient rights, deinstitutionalization, and disability rights movements. Because of these forces, capacity issues now permeate the fabric of everyday life, whether in the form of guardianship petitions, questions of capacity to consent to treatment, the ability to make a new will, or participation in human research. In seeking to resolve these issues, families, clinicians, and legal professionals increasingly turn to psychologists to assess a capacity and to provide empirically supported judgments that properly balance autonomy and protection for the individual. Psychologists have taken a leading role in the development of functional assessment instruments that measure important aspects of the capacity construct. In addition, psychology has been a major contributor to the scientific study of capacity. In collaboration with colleagues from medicine and law, psychologists have articulated crucial theoretical frameworks that integrate legal, clinical, and ethical dimensions of the capacity problem. This article focuses on the evolution of theory, law, science, and practice in the evaluation of capacity in older adults and its recent culmination in a series of interdisciplinary handbooks sponsored by the American Psychological Association and the American Bar Association.

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.

Okonkwo O, den Hollander JA, Martin RC, Belue K, Copeland JN, Harrell LE, Brockington JC, Clark DG, Marson DC. 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.

Impaired financial abilities in Parkinson's disease patients with mild cognitive impairment and dementia

PURPOSE

Financial capacity (FC) is an instrumental activity of daily living (IADL) critical to independent functioning and sensitive to cognitive impairment in dementia. Little is known about FC in cognitively impaired patients with Parkinson's disease (PD). The present study investigated FC in PD patients with prodromal and clinical dementia.

METHODS

Participants were 20 older controls and 35 PD patients who met consensus criteria for either mild cognitive impairment (PD-MCI, n = 18) or PD dementia (PDD, n = 17). FC was assessed using a standardized performance based measure consisting of 9 domain and two global scores (Financial Capacity Instrument; FCI) (1). FCI domain and global performance scores were compared across groups. Capacity impairment ratings (no impairment, mild/moderate impairment, severe impairment) were calculated for each PD patient's domain and global scores.

RESULTS

Relative to controls, PD-MCI patients were impaired on both FCI global scores and domains of basic monetary skills, financial concepts, and investment decision-making. Relative to both controls and PD-MCI patients, PDD patients were impaired on virtually all FCI variables. With respect to impairment ratings, greater than 50% of PD-MCI patients and greater than 90% of PDD patients were classified as either mild/moderate or severely impaired on the two FCI global scores.

CONCLUSIONS

Impairment of financial capacity is already present in PD-MCI and is advanced in PDD. Complex cognitively-mediated IADLs such as financial capacity appear to be impaired early in the course of PD dementia.

Clinical and ethical aspects of financial capacity in dementia: a commentary

In contrast to issues like treatment and research consent capacity, financial capacity has received relatively little clinical and ethical attention in the dementia literature. Yet issues of financial capacity emerge frequently in patients with Alzheimer's disease (AD), Parkinson's disease (PD) and related dementias, and commonly present ethical and clinical challenges for clinicians treating these patients. These issues include whether a patient with possible dementia has sufficient capacity independently to manage their financial affairs, needs referral for financial capacity assessment, and/or is being financially exploited or abused by others. The accurate identification, assessment and successful handling of such financial capacity issues can have a substantial impact on the financial and psychological well-being of patients and their family members. The present commentary presents an overview of financial capacity and associated clinical and ethical issues in dementia, and describes a set of possible clinician roles regarding these issues as they arise in clinical practice. The commentary concludes with a section describing educational resources available to clinicians and bioethicists seeking additional guidance in handling financial capacity issues. The ultimate goal of the paper is to focus clinical and ethical attention on a neglected capacity that is of fundamental importance for patients, families, and health care and legal professionals.

Clinical and ethical aspects of financial capacity in dementia: a commentary

In contrast to issues such as treatment and research consent capacity, financial capacity has received relatively little clinical and ethical attention in the dementia literature. Yet issues of financial capacity emerge frequently in patients with Alzheimer disease, Parkinson disease, and related dementias, and commonly present ethical and clinical challenges for clinicians treating these patients. These issues include whether a patient with possible dementia has sufficient capacity to manage independently their financial affairs, needs referral for financial capacity assessment, and/or is being financially exploited or abused by others. The accurate identification, assessment and successful handling of such financial capacity issues can have a substantial impact on the financial and psychological well-being of patients and their family members. This commentary presents an overview of financial capacity and associated clinical and ethical issues in dementia and describes a set of possible clinician roles regarding these issues as they arise in clinical practice. The commentary concludes with a section describing educational resources available to clinicians and bioethicists seeking additional guidance in handling financial capacity issues. The ultimate goal of the article is to focus clinical and ethical attention on a neglected capacity that is of fundamental importance for patients, families, and healthcare and legal professionals.

Common genetic variants in the CLDN2 and PRSS1-PRSS2 loci alter risk for alcohol-related and sporadic pancreatitis

Pancreatitis is a complex, progressively destructive inflammatory disorder. Alcohol was long thought to be the primary causative agent, but genetic contributions have been of interest since the discovery that rare PRSS1, CFTR and SPINK1 variants were associated with pancreatitis risk. We now report two associations at genome-wide significance identified and replicated at PRSS1-PRSS2 (P < 1 × 10(-12)) and X-linked CLDN2 (P < 1 × 10(-21)) through a two-stage genome-wide study (stage 1: 676 cases and 4,507 controls; stage 2: 910 cases and 4,170 controls). The PRSS1 variant likely affects disease susceptibility by altering expression of the primary trypsinogen gene. The CLDN2 risk allele is associated with atypical localization of claudin-2 in pancreatic acinar cells. The homozygous (or hemizygous in males) CLDN2 genotype confers the greatest risk, and its alleles interact with alcohol consumption to amplify risk. These results could partially explain the high frequency of alcohol-related pancreatitis in men (male hemizygote frequency is 0.26, whereas female homozygote frequency is 0.07).

Novel late-onset Alzheimer disease loci variants associate with brain gene expression

OBJECTIVE

Recent genome-wide association studies (GWAS) of late-onset Alzheimer disease (LOAD) identified 9 novel risk loci. Discovery of functional variants within genes at these loci is required to confirm their role in Alzheimer disease (AD). Single nucleotide polymorphisms that influence gene expression (eSNPs) constitute an important class of functional variants. We therefore investigated the influence of the novel LOAD risk loci on human brain gene expression.

METHODS

We measured gene expression levels in the cerebellum and temporal cortex of autopsied AD subjects and those with other brain pathologies (∼400 total subjects). To determine whether any of the novel LOAD risk variants are eSNPs, we tested their cis-association with expression of 6 nearby LOAD candidate genes detectable in human brain (ABCA7, BIN1, CLU, MS4A4A, MS4A6A, PICALM) and an additional 13 genes ±100 kb of these SNPs. To identify additional eSNPs that influence brain gene expression levels of the novel candidate LOAD genes, we identified SNPs ±100 kb of their location and tested for cis-associations.

RESULTS

CLU rs11136000 (p = 7.81 × 10(-4)) and MS4A4A rs2304933/rs2304935 (p = 1.48 × 10(-4)-1.86 × 10(-4)) significantly influence temporal cortex expression levels of these genes. The LOAD-protective CLU and risky MS4A4A locus alleles associate with higher brain levels of these genes. There are other cis-variants that significantly influence brain expression of CLU and ABCA7 (p = 4.01 × 10(-5)-9.09 × 10(-9)), some of which also associate with AD risk (p = 2.64 × 10(-2)-6.25 × 10(-5)).

CONCLUSIONS

CLU and MS4A4A eSNPs may at least partly explain the LOAD risk association at these loci. CLU and ABCA7 may harbor additional strong eSNPs. These results have implications in the search for functional variants at the novel LOAD risk loci.

Treatment consent capacity in patients with traumatic brain injury across a range of injury severity

OBJECTIVE

To investigate medical decision-making capacity (MDC) in patients with acute traumatic brain injury (TBI) across a range of injury severity.

METHODS

We evaluated MDC cross-sectionally 1 month after injury in 40 healthy controls and 86 patients with TBI stratified by injury severity (28 mild [mTBI], 15 complicated mild [cmTBI], 43 moderate/severe [msevTBI]). We compared group performance on the Capacity to Consent to Treatment Instrument and its 5 consent standards (expressing choice, reasonable choice, appreciation, reasoning, understanding). Capacity impairment ratings (no impairment, mild/moderate impairment, severe impairment) on the consent standards were also assigned to each participant with TBI using cut scores referenced to control performance.

RESULTS

One month after injury, the mTBI group performed equivalently to controls on all consent standards. In contrast, the cmTBI group was impaired relative to controls on the understanding standard. No differences emerged between the mTBI and cmTBI groups. The msevTBI group was impaired on almost all standards relative to both control and mTBI groups, and on the understanding standard relative to the cmTBI group. Capacity compromise (mild/moderate or severe impairment ratings) on the 3 clinically complex standards (understanding, reasoning, appreciation) occurred in 10%-30% of patients with mTBI, 50% of patients with cmTBI, and 50%-80% of patients with msevTBI.

CONCLUSIONS

One month following injury, MDC is largely intact in patients with mTBI, but is impaired in patients with cmTBI and msevTBI. Impaired MDC is prevalent in acute TBI and is strongly related to injury severity.

Financial capacity following traumatic brain injury: a six-month longitudinal study

OBJECTIVE

To longitudinally investigate financial capacity (FC) following traumatic brain injury (TBI).

DESIGN

Longitudinal study comparing FC in cognitively healthy adults and persons with moderate to severe TBI at time of acute hospitalization (Time 1) and at 6 months postinjury (Time 2).

SETTING

Inpatient brain injury rehabilitation unit.

PARTICIPANTS

Twenty healthy adult controls and 24 adult persons with moderate to severe TBI.

MAIN OUTCOME MEASURES

Participants were administered the Financial Capacity Instrument (FCI-9), a standardized instrument that measures performance on 18 financial tasks, 9 domains, and 2 global scores. Between- and within-group differences were examined for each FCI-9 domain and global scores. Using control group referenced cut scores, participants with TBI were also assigned an impairment rating (intact, marginal, or impaired) on each domain and global score.

RESULTS

At Time 1, participants with TBI performed significantly below controls on the majority of financial variables tested. At Time 2, participants with TBI demonstrated within group improvement on both simple and complex financial domains, but continued to perform below adult controls on complex financial domains and both global scores. Group by time interactions were significant for four domains and both global scores. At Time 1, high percentages of participants with TBI were assigned either "marginal" or "impaired" ratings on the domains and global scores, with significant percentage increases of "intact" ratings at Time 2.

CONCLUSIONS

Immediately following acute injury, persons with moderate to severe TBI show global impairment of FC. Findings indicate improvement of both simple and complex financial skills over a 6-month period, but continued impairment on more complex financial skills. Future studies should examine loss and recovery of FC following TBI over longer time periods and a wider range of injury severity.

Common variants at MS4A4/MS4A6E, CD2AP, CD33 and EPHA1 are associated with late-onset Alzheimer's disease

The Alzheimer Disease Genetics Consortium (ADGC) performed a genome-wide association study of late-onset Alzheimer disease using a three-stage design consisting of a discovery stage (stage 1) and two replication stages (stages 2 and 3). Both joint analysis and meta-analysis approaches were used. We obtained genome-wide significant results at MS4A4A (rs4938933; stages 1 and 2, meta-analysis P (P(M)) = 1.7 × 10(-9), joint analysis P (P(J)) = 1.7 × 10(-9); stages 1, 2 and 3, P(M) = 8.2 × 10(-12)), CD2AP (rs9349407; stages 1, 2 and 3, P(M) = 8.6 × 10(-9)), EPHA1 (rs11767557; stages 1, 2 and 3, P(M) = 6.0 × 10(-10)) and CD33 (rs3865444; stages 1, 2 and 3, P(M) = 1.6 × 10(-9)). We also replicated previous associations at CR1 (rs6701713; P(M) = 4.6 × 10(-10), P(J) = 5.2 × 10(-11)), CLU (rs1532278; P(M) = 8.3 × 10(-8), P(J) = 1.9 × 10(-8)), BIN1 (rs7561528; P(M) = 4.0 × 10(-14), P(J) = 5.2 × 10(-14)) and PICALM (rs561655; P(M) = 7.0 × 10(-11), P(J) = 1.0 × 10(-10)), but not at EXOC3L2, to late-onset Alzheimer's disease susceptibility.

Capacity to Consent to Research Participation in Adults With Malignant Glioma

Purpose

To investigate research consent capacity (RCC) in patients with malignant gliomas (MGs) and identify cognitive abilities and clinical factors associated with RCC in MG.

Patients and Methods

Participants were 22 healthy controls and 26 patients with diagnosed and histologically verified MG. All patients with MG were receiving various combinations of treatment (surgery, radiation, chemotherapy, medication). Both groups were administered a neurocognitive test battery and a standardized RCC measure (Capacity to Consent to Research Instrument [CCRI]). Capacity performance was evaluated across four core consent abilities (choice, appreciation, reasoning, understanding), and categorical capacity impairment ratings (no impairment, mild/moderate impairment, severe impairment) were also identified for individual patients with MG. Stepwise regression analyses identified cognitive predictors of CCRI performance in the MG group.

Results

The MG patient group performed significantly below the control group on the three clinically relevant consent standards (appreciation, reasoning, and understanding). Patients with MG performed equivalently to controls in evidencing a simple research participation choice. Approximately one third of patients with MG showed compromised impairment ratings (mild/moderate impairment or severe impairment) on the three consent abilities. Cognitive measures of phonemic and semantic word fluency predicted performance on the consent standards. Steroid treatment and anticonvulsant use were related to poorer CCRI performance.

Conclusion

A substantial portion of patients with MG after diagnosis show impairments in research consent capacity. Word fluency measures reflecting expressive language and executive function abilities are strongly associated with these consent impairments. This study highlights the importance of careful attention to consent issues when enrolling patients with MG in clinical trials and other research studies.

Brain metabolic correlates of decision making in amnestic mild cognitive impairment

Persons with amnestic mild cognitive impairment (MCI) have subtle impairments in medical decision-making capacity (MDC). We examined the relationship between proton magnetic resonance spectroscopy (MRS) and MDC in MCI. Twenty-nine MCI patients and 42 controls underwent MRS to obtain ratios of N-acetylaspartate (NAA)/Creatine (Cr), Choline (Cho)/Cr, and myo-Inositol (mI)/Cr of the posterior cingulate. They also completed the Capacity to Consent to Treatment Instrument (CCTI), a vignette-based instrument measuring decisional standards of expressing choice, appreciating consequences of choice, providing rational reasons for choice, and understanding treatment choices. Patients showed abnormal MRS ratios of mI/Cr and Cho/Cr compared to controls, and impairments on the CCTI understanding and reasoning Standards. Performance on the reasoning standard of the CCTI was correlated with NAA/Cr (r = .46, p < .05). The relationship of NAA/Cr with decision-making suggests a role for posterior cortical neuronal functioning in performance of complex IADLs in MCI.