Association between neuropsychological assessment and amyloid status in a clinical setting

OBJECTIVE

Large research cohorts show robust associations between neuropsychological tests and Alzheimer's disease (AD) biomarkers, but studies in clinical settings are limited. The increasing availability of AD biomarkers to the practicing clinician makes it important to understand the relationship between comprehensive clinical neuropsychological assessment and biomarker status. This study examined concordance between practicing clinical neuropsychologists' diagnostic impressions and AD biomarker status in patients seen at an outpatient medical center, with a secondary aim of defining the characteristics of discordant cases.

METHOD

Participants (N = 79) seen for clinical neuropsychological assessment who subsequently underwent lumbar puncture or amyloid positron emission tomography imaging were identified via retrospective chart review. Concordance between clinical neuropsychological diagnosis (non-AD, indeterminate, possible/probable AD) and AD biomarker status (negative, indeterminate, positive) was determined. Individual test score data were used to examine between-group differences based on amyloid status.

RESULTS

AD biomarker positive and negative patients did not differ on individual neuropsychological tests after correcting for multiple comparisons, though the small number of AD biomarker indeterminate individuals performed better than biomarker positive patients. However, there was 76.7% concordance between neuropsychologists' diagnostic impressions and AD biomarker status (88% sensitivity and 55% specificity of neuropsychological assessment in detecting AD biomarker status). AD biomarker negative patients diagnosed as possible/probable AD (discordant) versus non-AD (concordant) had significantly lower Neuropsychological Assessment Battery Story Delayed Recall, higher Wechsler Adult Intelligence Scale-Fourth Edition Coding, and higher Trail-Making A (i.e., an amnestic memory profile).

CONCLUSIONS

Comprehensive neuropsychological assessment showed modest concordance with AD biomarker status in patients seen in an outpatient medical center for routine clinical care. Low specificity for the clinical diagnosis of AD could be explained by the multiplicity of etiologies that cause memory impairment (i.e., TAR DNA-binding protein 43, suspected non-AD pathology). (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Antidementia Medication Use in Nursing Home Residents

BACKGROUND

Antidementia medication can provide symptomatic improvements in patients with Alzheimer's disease, but there is a lack of consensus guidance on when to start and stop treatment in the nursing home setting.

METHODS

We describe utilization patterns of cholinesterase inhibitors (ChEI) and memantine for 3,50,197 newly admitted NH residents with dementia between 2011 and 2018.

RESULTS

Overall, pre-admission use of antidementia medications declined from 2011 to 2018 (ChEIs: 44.5% to 36.9%; memantine: 27.4% to 23.2%). Older age, use of a feeding tube, and greater functional dependency were associated with lower odds of ChEI initiation. Coronary artery disease, parenteral nutrition, severe aggressive behaviors, severe cognitive impairment, and high functional dependency were associated with discontinuation of ChEIs. Comparison of clinical factors related to anti-dementia drug treatment changes from pre to post NH admission in 2011 and 2018 revealed a change toward lower likelihood of initiation of treatment among residents with more functional dependency and those with indicators of more complex illness as well as a change toward higher likelihood of discontinuation in residents having 2 or more hospital stays.

CONCLUSIONS

These prescribing trends highlight the need for additional research on the effects of initiating and discontinuing antidementia medications in the NH to provide clear guidance for clinicians when making treatment decisions for individual residents.

Changes in the burden of medications that may impair driving among older adults before and after a motor vehicle crash

BACKGROUND

Medications are one of the most easily modifiable risk factors for motor vehicle crashes (MVCs) among older adults, yet limited information exists on how the use of potentially driver-impairing (PDI) medications changes following an MVC. Therefore, we examined the number and types of PDI medication classes dispensed before and after an MVC.

METHODS

This observational study included Medicare fee-for-service beneficiaries aged ≥67 years who were involved in a police-reported MVC in New Jersey as a driver between 2008 and 2017. Analyses were conducted at the "person-crash" level because participants could be involved in more than one MVC. We examined the use of 36 PDI medication classes in the 120 days before and 120 days after MVC. We described the number and prevalence of PDI medication classes in the pre-MVC and post-MVC periods as well as the most common PDI medication classes started and stopped following the MVC.

RESULTS

Among 124,954 person-crashes, the mean (SD) age was 76.0 (6.5) years, 51.3% were female, and 83.9% were non-Hispanic White. The median (Q1 , Q3 ) number of PDI medication classes was 2 (1, 4) in both the pre-MVC and post-MVC periods. Overall, 20.3% had a net increase, 15.9% had a net decrease, and 63.8% had no net change in the number of PDI medication classes after MVC. Opioids, antihistamines, and thiazide diuretics were the top PDI medication classes stopped following MVC, at incidences of 6.2%, 2.1%, and 1.7%, respectively. The top medication classes started were opioids (8.3%), skeletal muscle relaxants (2.2%), and benzodiazepines (2.1%).

CONCLUSIONS

A majority of crash-involved older adults were exposed to multiple PDI medications before and after MVC. A greater proportion of person-crashes were associated with an increased rather than decreased number of PDI medications. The reasons why clinicians refrain from stopping PDI medications following an MVC remain to be elucidated.

Elevated Amyloid-β PET Scan and Cognitive and Functional Decline in Mild Cognitive Impairment and Dementia of Uncertain Etiology

BACKGROUND

Elevated amyloid-β (Aβ) on positron emission tomography (PET) scan is used to aid diagnosis of Alzheimer's disease (AD), but many prior studies have focused on patients with a typical AD phenotype such as amnestic mild cognitive impairment (MCI). Little is known about whether elevated Aβ on PET scan predicts rate of cognitive and functional decline among those with MCI or dementia that is clinically less typical of early AD, thus leading to etiologic uncertainty.

OBJECTIVE

We aimed to investigate whether elevated Aβ on PET scan predicts cognitive and functional decline over an 18-month period in those with MCI or dementia of uncertain etiology.

METHODS

In 1,028 individuals with MCI or dementia of uncertain etiology, we evaluated the association between elevated Aβ on PET scan and change on a telephone cognitive status measure administered to the participant and change in everyday function as reported by their care partner.

RESULTS

Individuals with either MCI or dementia and elevated Aβ (66.6% of the sample) showed greater cognitive decline compared to those without elevated Aβ on PET scan, whose cognition was relatively stable over 18 months. Those with either MCI or dementia and elevated Aβ were also reported to have greater functional decline compared to those without elevated Aβ, even though the latter group showed significant care partner-reported functional decline over time.

CONCLUSIONS

Elevated Aβ on PET scan can be helpful in predicting rates of both cognitive and functional decline, even among cognitively impaired individuals with atypical presentations of AD.

Changes in Antidementia Medications upon Admission to the Nursing Home: Who Decides and Why? Results From a National Survey of Nursing Home Administrators

OBJECTIVE

Little is known about who is involved and what factors influence changes in antidementia medications for older adults living in nursing homes. The study sought to describe factors associated with initiation and discontinuation of antidementia medications in nursing home residents with dementia.

DESIGN

National survey of nursing homes with ≥30 beds; homes with dementia units were oversampled.

SETTINGS AND PARTICIPANTS

Nursing home administrators [eg, Directors of Nursing (DoNs)].

METHODS

In 2022, 1293 homes were surveyed (response rate: 26.6%, n = 340). Weighted analyses provided nationally representative results corrected for nonresponse (n = 14,455).

RESULTS

DoNs reported that people always/almost always involved in antidementia medication decisions included nursing home prescriber (84.4%), nursing staff (33.2%), family (23.4%), resident (13.8%), community primary care provider (12.1%), and dementia specialist (5.8%). DoNs reported that antidementia medications were much more likely to be initiated if residents (55.8%) and family members (53.2%) wanted antidementia medications, a dementia specialist was involved (51.9%), resident had aggressive behaviors (44.8%), resisted care (31.6%), or had severe physical/cognitive impairment (22.3%). DoNs reported that antidementia medications were much more likely to be discontinued with dementia specialist involvement (46.5%), progression to severe impairment (39.2%), hospice involvement (31.5%), <6 months' prognosis (28.5%), emergence of aggressive behaviors (25.2%), or resisting care (19.0%) and much less likely to be discontinued if residents (30.2%) and family (27.3%) were reluctant to discontinue. One in 6 homes reported that residents had no immediate family/caregivers usually or almost always/always.

CONCLUSIONS AND IMPLICATIONS

DoNs report that family/caregivers and dementia specialists have significant influence on antidementia medication decisions in nursing homes, but many residents lack their involvement. Real-world evidence on the risks and benefits of antidementia medications in nursing homes is needed to inform clinical guidance about appropriate use of antidementia medications in nursing homes.

Distance From Home to Motor Vehicle Crash Location: Implications for License Restrictions Among Medically-At-Risk Older Drivers

In 30 states, licensing agencies can restrict the distance from home that "medically-at-risk" drivers are permitted to drive. However, where older drivers crash relative to their home or how distance to crash varies by medical condition is unknown. Using geocoded crash locations and residential addresses linked to Medicare claims, we describe how the relationship between distance from home to crash varies by driver characteristics. We find that a majority of crashes occur within a few miles from home with little variation across driver demographics or medical conditions. Thus, distance restrictions may not reduce crash rates among older adults, and the tradeoff between safety and mobility warrants consideration.

Feasibility of a Yoga Intervention for Individuals with Mild Cognitive Impairment: A Randomized Controlled Trial

Background: Yoga is a potentially low risk intervention for cognitive impairment that combines mental and physical practice and includes instruction on breathing, stress reduction, and mindfulness meditation. Previous research documents that yoga can target modifiable risk factors for mild cognitive impairment (MCI) progression. The authors describe a randomized feasibility trial of yoga for individuals with MCI. Methods: Participants were 37 individuals with amnestic MCI who were randomly assigned to receive 12 weeks of twice-weekly yoga intervention (YI) or healthy living education (HLE) classes. Acceptability and feasibility were assessed by tracking adverse events, class attendance, and participant satisfaction. Participants completed neuropsychological and mood measures as well as measures of potential intervention mechanisms at baseline and immediately postintervention. Results: Participants in both conditions reported high levels of satisfaction and reasonable class attendance rates. Home practice rates were low. There were no adverse events deemed related to the YI. Results showed a medium effect size in favor of the YI in visuospatial skills. The yoga group also showed a large effect size indicating decline in perceived stress compared with the HLE group, whereas HLE resulted in greater reductions in depressive symptoms after the intervention (large effect size). Conclusions: Study findings indicated that the YI was safe, modestly feasible, and acceptable to older adults with MCI. The authors found preliminary evidence that yoga may improve visuospatial functioning in individuals with MCI. Results support stress reduction as a possible mechanism for the YI. Future studies should address a YI in a larger sample and include strategies to enhance engagement and home practice.

Beta test of a mobile health application for dementia caregivers

BACKGROUND

Dementia caregivers are at risk for negative health outcomes. Caregiver interventions to address this risk are limited by time and personnel constraints. Mobile technology is one means of reaching many caregivers while mitigating these constraints. The aim of the current project was to obtain initial data from a month-long beta test of a new mobile health tablet App for dementia caregivers.

METHOD

A purposive sample of community-dwelling dementia caregivers was given access to the CARE-Well (Caregiver Assessment, Resources, and Education) App for one month. The App consisted of 6 primary sections: (1) Self-Assessment of Stress and Care Recipient Behavioral Problems; (2) Psychoeducation; (3) Goal Diary; (4) Managing Behavior Problems; (5) Online Message Forum; and (6) Video Library. Feedback was collected from caregivers in a qualitative interview following study completion. Data were analyzed via a mixed-methods approach.

RESULT

Caregivers (n = 10) were White, in their mid-60s (M = 66.2, SD = 12.12), and well educated (M = 16.00 years, SD = 1.63). Care recipients had either mild (80%) or moderate dementia (20%), and 90% had probable Alzheimer's disease. The average total time spent on the App across all participants was 754.29 minutes (SD = 1584.12). The most heavily used (in minutes) sections of the App were: Managing Behavior Problems (M = 592.10, SD = 1595.75), Video Library (M = 54.33, SD = 88.18) and Psychoeducation (M = 53.18, SD = 54.50). Qualitative feedback was predominantly positive. Caregivers reported Managing Behavior Problems to be the most helpful section followed by Psychoeducation and Online Message Forum. Caregivers reported difficulty with or disinterest in the Goal Diary section. In general, caregivers reported that the App would have been more helpful earlier in their care recipient's illness.

CONCLUSION

Results indicated that caregivers regularly used the App and provided mostly positive responses to content. Findings highlighted the importance of user feedback and an iterative approach for developing digital health technology for dementia caregivers. Future interventions that are introduced earlier in the disease process may be well-received and more beneficial to a wider range of dementia caregivers and their care recipients.

Novel blood test for early biomarkers of preeclampsia and Alzheimer's disease

A non-invasive and sensitive blood test has long been a goal for early stage disease diagnosis and treatment for Alzheimer's disease (AD) and other proteinopathy diseases. We previously reported that preeclampsia (PE), a severe pregnancy complication, is another proteinopathy disorder with impaired autophagy. We hypothesized that induced autophagy deficiency would promote accumulation of pathologic protein aggregates. Here, we describe a novel, sensitive assay that detects serum protein aggregates from patients with PE (n = 33 early onset and 33 late onset) and gestational age-matched controls (n = 77) as well as AD in both dementia and prodromal mild cognitive impairment (MCI, n = 24) stages with age-matched controls (n = 19). The assay employs exposure of genetically engineered, autophagy-deficient human trophoblasts (ADTs) to serum from patients. The aggregated protein complexes and their individual components, including transthyretin, amyloid β-42, α-synuclein, and phosphorylated tau231, can be detected and quantified by co-staining with ProteoStat, a rotor dye with affinity to aggregated proteins, and respective antibodies. Detection of protein aggregates in ADTs was not dependent on transcriptional upregulation of these biomarkers. The ROC curve analysis validated the robustness of the assay for its specificity and sensitivity (PE; AUC: 1, CI: 0.949-1.00; AD; AUC: 0.986, CI: 0.832-1.00). In conclusion, we have developed a novel, noninvasive diagnostic and predictive assay for AD, MCI and PE.

Anticholinergic/Sedative Drug Burden and Subjective Cognitive Decline in Older Adults at Risk of Alzheimer's Disease

BACKGROUND

Anticholinergic/sedative drug use, measured by the Drug Burden Index (DBI), has been linked to cognitive impairment in older adults. Subjective cognitive decline (SCD) may be among the first symptoms patients with Alzheimer's disease (AD) experience. We examined whether DBI values are associated with SCD in older adults at risk of AD. We hypothesized that increased DBI would be associated with greater SCD at older ages.

METHOD

Two-hundred-six community-dwelling, English-speaking adults (age = 65 ± 9 years) at risk of AD (42% apolipoprotein ε4 carriers; 78% with AD family history) were administered a single question to ascertain SCD: "Do you feel like your memory is becoming worse?" Response options were "No"; "Yes, but this does not worry me"; and "Yes, this worries me." DBI values were derived from self-reported medication regimens using older adult dosing recommendations. Adjusting for relevant covariates (comorbidities and polypharmacy), we examined independent effects of age and DBI on SCD, as well as the moderating effect of age on the DBI-SCD association at mean ± 1 SD of age.

RESULTS

Both SCD and anticholinergic/sedative drug burden were prevalent. Greater drug burden was predictive of SCD severity, but age alone was not. A significant DBI*Age interaction emerged with greater drug burden corresponding to more severe SCD among individuals age 65 and older.

CONCLUSION

Anticholinergic/sedative drug exposure was associated with greater SCD in adults 65 and older at risk for AD. Longitudinal research is needed to understand if this relationship is a pre-clinical marker of neurodegenerative disease and predictive of future cognitive decline.

Peripheral Markers of Vascular Endothelial Dysfunction Show Independent but Additive Relationships with Brain-Based Biomarkers in Association with Functional Impairment in Alzheimer's Disease

BACKGROUND

Cerebrovascular dysfunction confers risk for functional decline in Alzheimer's disease (AD), yet the clinical interplay of these two pathogenic processes is not well understood.

OBJECTIVE

We utilized Alzheimer's Disease Neuroimaging Initiative (ADNI) data to examine associations between peripherally derived soluble cell adhesion molecules (CAMs) and clinical diagnostic indicators of AD.

METHODS

Using generalized linear regression models, we examined cross-sectional relationships of soluble plasma vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and E-Selectin to baseline diagnosis and functional impairment (clinical dementia rating sum-of-boxes, CDR-SB) in the ADNI cohort (n = 112 AD, n = 396 mild cognitive impairment (MCI), n = 58 cognitively normal). We further analyzed associations of these biomarkers with brain-based AD biomarkers in a subset with available cerebrospinal fluid (CSF) data (n = 351). p-values derived from main effects and interaction terms from the linear regressions were used to assess the relationship between independent and dependent variables for significance (significance level was set at 0.05 a priori for all analysis).

RESULTS

Higher mean VCAM-1 (p = 0.0026) and ICAM-1 (p = 0.0189) levels were found in AD versus MCI groups; however, not in MCI versus cognitively normal groups. Only VCAM-1 was linked with CDR-SB scores (p = 0.0157), and APOE ɛ4 genotype modified this effect. We observed independent, additive associations when VCAM-1 and CSF amyloid-β (Aβ42), total tau, phosphorylated tau (P-tau), or P-tau/Aβ42 (all < p = 0.01) were combined in a CDR-SB model; ICAM-1 showed a similar pattern, but to a lesser extent.

CONCLUSION

Our findings indicate independent associations of plasma-based vascular biomarkers and CSF biomarkers with AD-related clinical impairment.

Video feedback intervention for cognitively impaired older drivers: A randomized clinical trial

INTRODUCTION

This clinical trial aimed to determine whether in-car video feedback about unsafe driving events (UDE) to cognitively impaired older drivers and family members leads to a reduction in such driving behaviors.

METHODS

We randomized 51 cognitively impaired older drivers to receive either (1) a weekly progress report with recommendations and access to their videos, or (2) video monitoring alone without feedback over 3 months.

RESULTS

UDE frequency/1000 miles was reduced by 12% in feedback (rate ratio [RR] = 0.88, 95% confidence interval [CI] = .58-1.34), while remaining constant with only monitoring (RR = 1.01, 95% CI = .68-1.51). UDE severity/1000 miles was reduced by 37% in feedback (RR = 0.63, 95% CI = .31-1.27), but increased by 40% in monitoring (RR = 1.40, 95% CI = .68-2.90). Cognitive impairment moderated intervention effects (P = .03) on UDE frequency.

DISCUSSION

Results suggest the potential to improve driving safety among mild cognitively impaired older drivers using a behavior modification approach aimed at problem behaviors detected in their natural driving environment.

The relationship between cerebral and retinal microbleeds in cerebral amyloid angiopathy (CAA): A pilot study

BACKGROUND

The standard in vivo diagnostic imaging technique for cerebral amyloid angiopathy (CAA) is costly and thereby of limited utility for point-of-care diagnosis and monitoring of treatment efficacy. Recent recognition that retinal changes may reflect cerebral changes in neurodegenerative disease provides an ideal opportunity for development of accessible and cost-effective biomarkers for point-of-care use in the detection and monitoring of CAA. In this pilot study, we examined structural and angiographic retinal changes in CAA patients relative to a control group, and compared retinal and cerebral pathology in a group of CAA patients.

METHODS

We used spectral domain optical coherence tomography (SD-OCT) to image the retina and compared retinal microbleeds to both cerebral microbleeds and white matter hyperintensities (WMH) in CAA patients, as seen on MRI. We compared retinal angiographic changes, along with structural retinal neuronal layer changes in CAA patients and cognitively normal older adults, and examined the relationship between retinal and cerebral microbleeds and cognition in CAA patients.

RESULTS

We found a trend level correlation between retinal and cerebral microbleeds in CAA patients. Moreover, we found a significant correlation between retinal microbleeds and episodic memory performance in CAA patients. There were no significant group differences between CAA patients and cognitively normal older adults on retinal angiographic or structural measurements.

CONCLUSION

Retinal microbleeds may reflect degree of cerebral microbleed burden in CAA. This picture was complicated by systolic hypertension in the CAA group, which is a confounding factor for the interpretation of these data. Our results stimulate motivation for pursuit of a more comprehensive prospective study to determine the feasibility of retinal biomarkers in CAA.

Pilot study of an Alzheimer's disease risk assessment program in a primary care setting

INTRODUCTION

The goal of this study was to pilot a referral-based cognitive screening and genetic testing program for Alzheimer's disease (AD) risk assessment in a primary care setting.

METHODS

Primary care providers (PCPs; N = 6) referred patients (N = 94; M = 63 years) to the Rhode Island Alzheimer's Disease Prevention Registry for apolipoprotein E (APOE) genotyping and cognitive screening. PCPs disclosed test results to patients and counseled them about risk factor modification.

RESULTS

Compared to the Registry as a whole, participants were younger, more likely to be non-White, and had lower cognitive screening scores. Mild cognitive impairment participants correctly reported a higher perceived risk of developing AD. Patients who recalled being counseled about modifiable risk factors were more likely to report positive health behavior changes.

DISCUSSION

A referral-based program for cognitive and genetic AD risk assessment in a primary care setting is feasible, acceptable to patients, and yielded a more demographically diverse sample than an AD prevention registry.

Cognition After Lowering LDL-Cholesterol With Evolocumab

BACKGROUND

The EBBINGHAUS (Evaluating PCSK9 Binding Antibody Influence on Cognitive Health in High Cardiovascular Risk Subjects) trial demonstrated that evolocumab added to a background statin did not affect cognitive performance in a subset of 1,204 patients enrolled in FOURIER (Further Cardiovascular Outcomes Research With PCSK9 inhibitors in Subjects With Elevated Risk).

OBJECTIVES

The authors describe patient-reported cognition in the entire FOURIER trial using a self-survey.

METHODS

FOURIER was a randomized, double-blind, placebo-controlled trial involving patients with atherosclerotic cardiovascular disease and low-density lipoprotein cholesterol (LDL-C) levels ≥70 mg/dl or non-high-density cholesterol ≥100 mg/dl despite statin therapy. At the final visit, patients completed a 23-item survey on memory and executive domains from the Everyday Cognition (ECog) scale. Patients compared their levels of everyday function at the end of the trial with their levels at the beginning and scored as 1 (no change or improvement), 2 (occasionally worse), 3 (consistently little worse), or 4 (consistently much worse). ECog scores were compared by the 2 randomized treatment arms and by achieved LDL-C at 4 weeks.

RESULTS

A total of 22,655 patients completed ECog after a median duration of 2.2 years. The proportions of patients reporting cognitive decline (ECog score ≥2) at the end of the study were similar for placebo versus evolocumab, both for total score 3.6% versus 3.7% (p = 0.62) and for subdomains (memory, 5.8% vs. 6.0%; total executive, 3.6% vs. 3.7%). The proportion of patients reporting a decline in total cognitive score was similar among the 2,338 patients who achieved very low LDL-C levels (<20 mg/dl) compared to the 3,613 patients with LDL-C ≥100 mg/dl (3.8% vs. 4.5%, p = 0.57).

CONCLUSIONS

The addition of evolocumab to maximally tolerated statin therapy had no impact on patient-reported cognition after an average of 2.2 years of treatment, even among patients who achieved LDL-C <20 mg/dl.

Evaluation of Naturalistic Driving Behavior Using In-Vehicle Monitoring Technology in Preclinical and Early Alzheimer's Disease

Cognitive impairment is a significant risk factor for hazardous driving among older drivers with Alzheimer's dementia, but little is known about how the driving behavior of mildly symptomatic compares with those in the preclinical, asymptomatic phase of Alzheimer's disease (AD). This study utilized two in-car technologies to characterize driving behavior in symptomatic and preclinical AD. The goals of this pilot study were to (1) describe unsafe driving behaviors in individuals with symptomatic early AD using G-force triggered video capture and (2) compare the driving habits of these symptomatic AD drivers to two groups of cognitively normal drivers, those with and those without evidence of cerebral amyloidosis (CN/A+ and CN/A-) using a global positioning system (GPS) datalogger. Thirty-three drivers (aged 60+ years) were studied over 3 months. G-force triggered video events captured instances of near-misses/collisions, traffic violations, risky driver conduct, and driving fundamentals. GPS data were sampled every 30 s and all instances of speeding, hard braking, and sudden acceleration were recorded. For the early AD participants, video capture identified driving unbelted, late response, driving too fast for conditions, traffic violations, poor judgment, and not scanning intersections as the most frequently occurring safety errors. When evaluating driving using the GPS datalogger, hard breaking events occurred most frequently on a per trip basis across all three groups. The CN/A+ group had the lowest event rate across all three event types with lower instances of speeding. Slower psychomotor speed (Trail Making Part A) was associated with fewer speeding events, more hard acceleration events, and more overall events. GPS tracked instances of speeding were correlated with total number of video-captured near-collisions/collisions and driving fundamentals. Results demonstrate the utility of electronic monitoring to identify potentially unsafe driving events in symptomatic and preclinical AD. Results suggest that drivers with preclinical AD may compensate for early, subtle cognitive changes by driving more slowly and cautiously than healthy older drivers or those with cognitive impairment. Self-regulatory changes in driving behavior appear to occur in the preclinical phase of AD, but safety concerns may not arise until symptoms of cognitive impairment emerge and the ability to self-monitor declines.

A 2.5-Year Longitudinal Assessment of Naturalistic Driving in Preclinical Alzheimer's Disease

BACKGROUND

Emerging evidence shows that cognitively normal older adults with preclinical Alzheimer's disease (AD) make more errors and are more likely to receive a marginal/fail rating on a standardized road test compared to older adults without preclinical AD, but the extent to which preclinical AD impacts everyday driving behavior is unknown.

OBJECTIVE

To examine self-reported and naturalistic longitudinal driving behavior among persons with and without preclinical AD.

METHOD

We prospectively followed cognitively normal drivers (aged 65 + years) with (n = 10) and without preclinical AD (n = 10) for 2.5 years. Preclinical AD was assessed using amyloid positron emission tomography (PET) with Pittsburgh Compound B. The Driving Habits Questionnaire assessed self-reported driving outcomes. Naturalistic driving was captured using a commercial GPS data logger plugged into the on-board diagnostics II port of each participant's vehicle. Data were sampled every 30 seconds and all instances of speeding, hard braking, and sudden acceleration were recorded.

RESULTS

Preclinical AD participants went to fewer places/unique destinations, traveled fewer days, and took fewer trips than participants without preclinical AD. The preclinical AD group reported a smaller driving space, greater dependence on other drivers, and more difficulty driving due to vision difficulties. Persons with preclinical AD had fewer trips with any aggression and showed a greater decline across the 2.5-year follow-up period in the number of days driving per month and the number of trips between 1-5 miles.

CONCLUSION

Changes in driving occur even during the preclinical stage of AD.

Evaluation of the Driving Safety of Visually Impaired Bioptic Drivers Based on Critical Events in Naturalistic Driving

Purpose

Visually impaired people may be allowed to drive if they wear bioptic telescopes. Bioptic driving safety is debatable, especially given that the telescopes are seldom used by most bioptic drivers. This preliminary study examined bioptic safety based on critical events that occurred in naturalistic daily driving.

Methods

Daily driving activities were recorded using in-car video recorders in 20 bioptic drivers (median age 55, visual acuity, 20/60-160) and 19 control subjects (median age 74) for two to eight weeks. In a secondary analysis, these subjects were compared with 44 cognitively impaired drivers with normal vision (median age 75).

Results

In 292 hours of driving by bioptic drivers and 169 hours by control drivers, seven bioptic drivers and three control drivers had eight and four near-collisions, respectively. Near-collision survival times were not significantly different between the two groups (hazard ratio [HR] = 1.93, P = 0.591) according to Cox hazards regression. Even without compensation for bioptic drivers' longer driving exposure, their odds ratio (OR) was not statistically significant (OR = 2.88, P = 0.18). When including cognitively impaired drivers with normal vision, cognition was a significant predictor of near collisions (HR = 3.86, P = 0.036), but vision loss was not (HR = 0.47, P = 0.317).

Conclusions

This preliminary study failed to find any evidence suggesting that bioptic drivers were more prone to near-collision than healthy drivers. Vision might be a less-significant factor than cognition.

Translational Relevance

Given that bioptic drivers use the telescope for less than 2% of the driving time, this study suggests that driving safety might not be substantially affected even when visual acuity is in the low vision range.

Impaired integration of object feature knowledge in amnestic mild cognitive impairment

OBJECTIVE

Accessing semantic representations of real-world objects requires integration of multimodal perceptual features that are represented across relevant neocortical areas. Early Alzheimer's disease (AD) neuropathology, including neurofibrillary tangles in the perirhinal cortex as well as disrupted cortico-cortical connectivity, would be expected to disrupt the integration of object features. This integration deficit may underlie AD patients' semantic memory deficits and would be predicted to be more prominent for living objects, which tend to be more defined by sensory features compared with nonliving objects.

METHOD

Two experiments were conducted to assess feature integration in cognitively healthy older adults and patients with amnestic mild cognitive impairment (MCI). In both experiments, pictures of real-world objects were presented in congruent or incongruent colors. Participants were instructed to make a speeded color congruency judgment (Experiment 1) or name the presented surface color (Experiment 2).

RESULTS

Across experiments, MCI patients showed a selective integration deficit for living, but not nonliving, objects across both experimental paradigms that was consistent with a deterioration in semantic structural representations rather than a deficit in controlled semantic retrieval. Planned secondary analyses with a subset of patients (Experiment 1) for whom PET imaging was available indicated that the degree of impairment was associated with the magnitude of cortical amyloid burden.

CONCLUSIONS

These findings suggest that early AD pathology leads to impaired integration of distributed semantic object representations. The development of integration tasks as sensitive markers of early AD pathology may lead to more effective diagnostic tools for early detection and intervention. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Disruption of cholinergic neurotransmission, within a cognitive challenge paradigm, is indicative of Aβ-related cognitive impairment in preclinical Alzheimer's disease after a 27-month delay interval

BACKGROUND

Abnormal beta-amyloid (Aβ) is associated with deleterious changes in central cholinergic tone in the very early stages of Alzheimer's disease (AD), which may be unmasked by a cholinergic antagonist (J Prev Alzheimers Dis 1:1-4, 2017). Previously, we established the scopolamine challenge test (SCT) as a "cognitive stress test" screening measure to identify individuals at risk for AD (Alzheimer's & Dementia 10(2):262-7, 2014) (Neurobiol. Aging 36(10):2709-15, 2015). Here we aim to demonstrate the potential of the SCT as an indicator of cognitive change and neocortical amyloid aggregation after a 27-month follow-up interval.

METHODS

Older adults (N = 63, aged 55-75 years) with self-reported memory difficulties and first-degree family history of AD completed the SCT and PET amyloid imaging at baseline and were then seen for cognitive testing at 9, 18, and 27 months post-baseline. Repeat PET amyloid imaging was completed at the time of the 27-month exam.

RESULTS

Significant differences in both cognitive performance and in Aβ neocortical burden were observed between participants who either failed vs. passed the SCT at baseline, after a 27-month follow-up period.

CONCLUSIONS

Cognitive response to the SCT (Alzheimer's & Dementia 10(2):262-7, 2014) at baseline is related to cognitive change and PET amyloid imaging results, over the course of 27 months, in preclinical AD. The SCT may be a clinically useful screening tool to identify individuals who are more likely to both have positive evidence of amyloidosis on PET imaging and to show measurable cognitive decline over several years.

Driving Safety of Cognitively-Impaired Drivers Based on Near Collisions in Naturalistic Driving

Background

Controlled naturalistic driving for examining impacts of cognitive impairment on driving safety is rare.

Objective

Evaluating the safety among drivers with mild cognitive impairment based on near collision incidents using naturalistic driving, and investigating its correlation with cognitive measures.

Methods

Frequency of near collisions of 44 cognitively impaired [Age = 75.1(±6.7), MMSE = 25.5(±2.5)] and 19 control group drivers [Age = 72.5(±7.8), MMSE = 29.3(±0.8)] were obtained from two weeks of recorded driving. Survival time free of predicted collision based on a previously established near-collision to collision estimate ratio of 11 : 1, for 140 hours of driving exposure was calculated. Participants were also tested using Mini-Mental Status Examination (MMSE), Trail A, and Trail B. Spearman correlation and Cox survival analysis were conducted.

Results

Near collision frequency per driving hour was correlated with MMSE (r = -0.258, p = 0.041). Survival analyses showed that cognitively impaired drivers might be prone to higher probability of having collision (p = 0.056) with a hazard ratio of 5.78 (p = 0.092). When all participants were combined, there was a significant difference (p < 0.017) in all the three cognitive measures between drivers with and without predicted collision, which were not significant within patient or control group alone (p > 0.186). Cox regression analysis showed MMSE as the only significant factor (p < 0.025) for survival time of predicted collision, but not age, gender, or driving experience.

Conclusion

The association between driving critical events and cognitive measures suggests that some drivers with mild cognitive impairment might have an elevated driving collision risk compared to control drivers. Standard clinical cognitive measures may be reasonable predictors.

Phasic alerting enhances spatial orienting in healthy aging but not in mild cognitive impairment

OBJECTIVE

Previous studies in young adults have demonstrated strong functional links between phasic alerting and exogenous orienting. The present study examined changes in the dynamic interaction between these attentional networks in healthy aging and in amnestic mild cognitive impairment.

METHOD

Healthy young adults, healthy older adults, and patients with amnestic mild cognitive impairment (MCI) were asked to identify as quickly as possible the color of a target stimulus that appeared within one of 2 peripheral boxes. Orienting was manipulated by a brief flashing of the same (valid cue) or opposite (invalid cue) box in which the target subsequently appeared. Alerting was manipulated by presenting an auditory white noise burst simultaneously with the visual orienting cue on half of the trials.

RESULTS

All 3 groups displayed significant alerting and orienting effects but differed in the nature of the interaction between alerting and orienting. As expected, young adults displayed increased orienting under high alerting conditions through a selective enhancement of validly cued targets. While older adults displayed a greater effect of alerting on orienting compared to young adults, MCI patients did not display a significant interaction between attentional networks.

CONCLUSIONS

Results provide support for the presence of increased compensatory interactions between attentional networks in healthy aging that may be no longer effective with the emergence of clinical symptoms in MCI. The demonstration of qualitatively distinct effects of healthy aging and MCI suggests that behavioral tests of attentional network interactions may serve as cognitive markers in individuals at increased risk for developing AD. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Early-Stage Alzheimer's Disease Is Associated with Simultaneous Systemic and Central Nervous System Dysregulation of Insulin-Linked Metabolic Pathways

BACKGROUND

Brain insulin resistance is a well-recognized abnormality in Alzheimer's disease (AD) and the likely mediator of impaired glucose utilization that emerges early and progresses with disease severity. Moreover, the rates of mild cognitive impairment (MCI) or AD are significantly greater in people with diabetes mellitus or obesity.

OBJECTIVE

This study was designed to determine whether systemic and central nervous system (CNS) insulin resistant disease states emerge together and thus may be integrally related.

METHODS

Insulin-related molecules were measured in paired human serum and cerebrospinal fluid (CSF) samples from 19 with MCI or early AD, and 21 controls using a multiplex ELISA platform.

RESULTS

In MCI/AD, both the CSF and serum samples had significantly elevated mean levels of C-peptide and an incretin, and reduced expression of Visfatin, whereas only CSF showed significant reductions in insulin and leptin and only serum had increased glucagon, PAI-1, and ghrelin. Although the overall CSF and serum responses reflected insulin resistance together with insulin deficiency, the specific alterations measured in CSF and serum were different.

CONCLUSION

In MCI and early-stage AD, CNS and systemic insulin-related metabolic dysfunctions, including insulin resistance, occur simultaneously, suggesting that they are integrally related and possibly mediated similar pathogenic factors.

A Naturalistic Study of Driving Behavior in Older Adults and Preclinical Alzheimer Disease: A Pilot Study

A clinical consequence of symptomatic Alzheimer's disease (AD) is impaired driving performance. However, decline in driving performance may begin in the preclinical stage of AD. We used a naturalistic driving methodology to examine differences in driving behavior over one year in a small sample of cognitively normal older adults with ( n = 10) and without ( n = 10) preclinical AD. As expected with a small sample size, there were no statistically significant differences between the two groups, but older adults with preclinical AD drove less often, were less likely to drive at night, and had fewer aggressive behaviors such as hard braking, speeding, and sudden acceleration. The sample size required to power a larger study to determine differences was calculated.

Tau and Amyloid Positron Emission Tomography Imaging Predict Driving Performance Among Older Adults with and without Preclinical Alzheimer's Disease

Abnormal levels of Alzheimer's disease (AD) biomarkers, measured by positron emission tomography imaging using amyloid-based radiotracers and cerebrospinal fluid, are associated with impaired driving performance in older adults. We examined whether preclinical AD staging, defined using amyloid imaging and tau imaging using the radiotracer T807 (AKA flortaucipir or AV-1451), was associated with receiving a marginal/fail rating on a standardized road test (n = 42). Participants at Stage 2 (positive amyloid and tau scans) of preclinical AD were more likely to receive a marginal/fail rating compared to participants at Stage 0 or 1. Stage 2 preclinical AD may manifest in worse driving performance.

Detection of Lane-Change Events in Naturalistic Driving Videos

Lane changes are important behaviors to study in driving research. Automated detection of lane-change events is required to address the need for data reduction of a vast amount of naturalistic driving videos. This paper presents a method to deal with weak lane-marker patterns as small as a couple of pixels wide. The proposed method is novel in its approach to detecting lane-change events by accumulating lane-marker candidates over time. Since the proposed method tracks lane markers in temporal domain, it is robust to low resolution and many different kinds of interferences. The proposed technique was tested using 490 h of naturalistic driving videos collected from 63 drivers. The lane-change events in a 10-h video set were first manually coded and compared with the outcome of the automated method. The method's sensitivity was 94.8% and the data reduction rate was 93.6%. The automated procedure was further evaluated using the remaining 480-h driving videos. The data reduction rate was 97.4%. All 4971 detected events were manually reviewed and classified as either true or false lane-change events. Bootstrapping showed that the false discovery rate from the larger data set was not significantly different from that of the 10-h manually coded data set. This study demonstrated that the temporal processing of lane markers is an effcient strategy for detecting lane-change events involving weak lane-marker patterns in naturalistic driving.

Blood-Cerebrospinal Fluid Barrier Gradients in Mild Cognitive Impairment and Alzheimer's Disease: Relationship to Inflammatory Cytokines and Chemokines

Background: The pathophysiology underlying altered blood-cerebrospinal fluid barrier (BCSFB) function in Alzheimer's disease (AD) is unknown but may relate to endothelial cell activation and cytokine mediated inflammation. Methods: Cerebrospinal fluid (CSF) and peripheral blood were concurrently collected from cognitively healthy controls (N = 21) and patients with mild cognitive impairment (MCI) (N = 8) or AD (N = 11). The paired serum and CSF samples were assayed for a panel of cytokines, chemokines, and related trophic factors using multiplex ELISAs. Dominance analysis models were conducted to determine the relative importance of the inflammatory factors in relationship to BCSFB permeability, as measured by CSF/serum ratios for urea, creatinine, and albumin. Results: BCSFB disruption to urea, a small molecule distributed by passive diffusion, had a full model coefficient of determination (r²) = 0.35, and large standardized dominance weights (>0.1) for monocyte chemoattractant protein-1, interleukin (IL)-15, IL-1rα, and IL-2 in serum. BCSFB disruption to creatinine, a larger molecule governed by active transport, had a full model r² = 0.78, and large standardized dominance weights for monocyte inhibitor protein-1b in CSF and tumor necrosis factor-α in serum. BCSFB disruption to albumin, a much larger molecule, had a full model r² = 0.62, and large standardized dominance weights for IL-17a, interferon-gamma, IL-2, and VEGF in CSF, as well IL-4 in serum. Conclusions: Inflammatory proteins have been widely documented in the AD brain. The results of the current study suggest that changes in BCSFB function resulting in altered permeability and transport are related to expression of specific inflammatory proteins, and that the shifting distribution of these proteins from serum to CSF in AD and MCI is correlated with more severe perturbations in BCSFB function.

The Modified Telephone-Administered Minnesota Cognitive Acuity Screen for Mild Cognitive Impairment

OBJECTIVE

This study aimed to compare the sensitivity and specificity of a modified version of the Minnesota Cognitive Acuity Screen (MCAS-m), by adding learning and recognition memory components, to the original version MCAS to distinguish amnestic mild cognitive impairment (aMCI) from healthy controls (HCs).

METHODS/DESIGN

A total of 30 individuals with aMCI and 30 HCs underwent neuropsychological testing, neurologic examination, laboratory, and brain imaging tests. Once diagnosis was confirmed, participants completed the MCAS and MCAS-m in counterbalanced order.

RESULTS

The average administration time was 12.6 minutes for the MCAS and 13.5 minutes for the MCAS-m. Receiver operating characteristic curve analyses showed that the MCAS-m demonstrated 97% sensitivity and 97% specificity for distinguishing between aMCI and HC versus 97% and 87%, respectively, for the original MCAS in this sample.

CONCLUSIONS

Both the MCAS and the MCAS-m were highly sensitive when distinguishing between normal cognition and aMCI; however, the MCAS-m demonstrated a 10% increase in specificity compared to the original version. Improved specificity is particularly relevant to screening in larger community samples with lower base rates of MCI than clinic populations. This modified screening measure presents a brief and cost-effective tool for identifying MCI. Given the risk of progression from aMCI to Alzheimer disease dementia (AD), the MCAS-m represents a modest improvement in telephone-administered methods for the early detection of AD.

Clinical efficacy and safety of achieving very low LDL-cholesterol concentrations with the PCSK9 inhibitor evolocumab: a prespecified secondary analysis of the FOURIER trial

BACKGROUND

LDL cholesterol is a well established risk factor for atherosclerotic cardiovascular disease. How much one should or safely can lower this risk factor remains debated. We aimed to explore the relationship between progressively lower LDL-cholesterol concentrations achieved at 4 weeks and clinical efficacy and safety in the FOURIER trial of evolocumab, a monoclonal antibody to proprotein convertase subtilisin-kexin type 9 (PCSK9).

METHODS

In this prespecified secondary analysis of 25 982 patients from the randomised FOURIER trial, the relationship between achieved LDL-cholesterol concentration at 4 weeks and subsequent cardiovascular outcomes (primary endpoint was the composite of cardiovascular death, myocardial infarction, stroke, coronary revascularisation, or unstable angina; key secondary endpoint was the composite of cardiovascular death, myocardial infarction, or stroke) and ten prespecified safety events of interest was examined over a median of 2·2 years of follow-up. We used multivariable modelling to adjust for baseline factors associated with achieved LDL cholesterol. This trial is registered with ClinicalTrials.gov, number NCT01764633.

FINDINGS

Between Feb 8, 2013, and June 5, 2015, 27 564 patients were randomly assigned a treatment in the FOURIER study. 1025 (4%) patients did not have an LDL cholesterol measured at 4 weeks and 557 (2%) had already had a primary endpoint event or one of the ten prespecified safety events before the week-4 visit. From the remaining 25 982 patients (94% of those randomly assigned) 13 013 were assigned evolocumab and 12 969 were assigned placebo. 2669 (10%) of 25 982 patients achieved LDL-cholesterol concentrations of less than 0·5 mmol/L, 8003 (31%) patients achieved concentrations between 0·5 and less than 1·3 mmol/L, 3444 (13%) patients achieved concentrations between 1·3 and less than 1·8 mmol/L, 7471 (29%) patients achieved concentrations between 1·8 to less than 2·6 mmol/L, and 4395 (17%) patients achieved concentrations of 2·6 mmol/L or higher. There was a highly significant monotonic relationship between low LDL-cholesterol concentrations and lower risk of the primary and secondary efficacy composite endpoints extending to the bottom first percentile (LDL-cholesterol concentrations of less than 0·2 mmol/L; p=0·0012 for the primary endpoint, p=0·0001 for the secondary endpoint). Conversely, no significant association was observed between achieved LDL cholesterol and safety outcomes, either for all serious adverse events or any of the other nine prespecified safety events.

INTERPRETATION

There was a monotonic relationship between achieved LDL cholesterol and major cardiovascular outcomes down to LDL-cholesterol concentrations of less than 0·2 mmol/L. Conversely, there were no safety concerns with very low LDL-cholesterol concentrations over a median of 2·2 years. These data support further LDL-cholesterol lowering in patients with cardiovascular disease to well below current recommendations.

FUNDING

Amgen.

Cognitive Function in a Randomized Trial of Evolocumab

Background Findings from clinical trials of proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors have led to concern that these drugs or the low levels of low-density lipoprotein (LDL) cholesterol that result from their use are associated with cognitive deficits. Methods In a subgroup of patients from a randomized, placebo-controlled trial of evolocumab added to statin therapy, we prospectively assessed cognitive function using the Cambridge Neuropsychological Test Automated Battery. The primary end point was the score on the spatial working memory strategy index of executive function (scores range from 4 to 28, with lower scores indicating a more efficient use of strategy and planning). Secondary end points were the scores for working memory (scores range from 0 to 279, with lower scores indicating fewer errors), episodic memory (scores range from 0 to 70, with lower scores indicating fewer errors), and psychomotor speed (scores range from 100 to 5100 msec, with faster times representing better performance). Assessments of cognitive function were performed at baseline, week 24, yearly, and at the end of the trial. The primary analysis was a noninferiority comparison of the mean change from baseline in the score on the spatial working memory strategy index of executive function between the patients who received evolocumab and those who received placebo; the noninferiority margin was set at 20% of the standard deviation of the score in the placebo group. Results A total of 1204 patients were followed for a median of 19 months; the mean (±SD) change from baseline over time in the raw score for the spatial working memory strategy index of executive function (primary end point) was -0.21±2.62 in the evolocumab group and -0.29±2.81 in the placebo group (P<0.001 for noninferiority; P=0.85 for superiority). There were no significant between-group differences in the secondary end points of scores for working memory (change in raw score, -0.52 in the evolocumab group and -0.93 in the placebo group), episodic memory (change in raw score, -1.53 and -1.53, respectively), or psychomotor speed (change in raw score, 5.2 msec and 0.9 msec, respectively). In an exploratory analysis, there were no associations between LDL cholesterol levels and cognitive changes. Conclusions In a randomized trial involving patients who received either evolocumab or placebo in addition to statin therapy, no significant between-group difference in cognitive function was observed over a median of 19 months. (Funded by Amgen; EBBINGHAUS ClinicalTrials.gov number, NCT02207634 .).

Video Feedback Intervention to Enhance the Safety of Older Drivers With Cognitive Impairment

OBJECTIVE

To demonstrate that g-force technology can be used to help older adults with cognitive impairment improve their driving safety as part of an in-car video feedback intervention.

METHOD

Unsafe driving events triggered g-forces leading to capture of video clips. The program included 3 mo of monitoring without intervention, 3 mo of intervention (weekly written progress reports, a DVD of unsafe driving events, and weekly telephone contacts), and 3 mo of postintervention monitoring.

RESULTS

Mean total unsafe driving events per 1,000 miles were reduced from baseline by 38% for 9 of 12 participants during the intervention and by 55% for 7 participants during postintervention monitoring. Mean total unsafe driving severity scores per 1,000 miles were reduced from baseline by 43% during the intervention and by 56% during postintervention monitoring.

CONCLUSION

Preliminary results suggest that driving safety among older drivers with cognitive impairment can be improved using a behavior modification approach aimed at problem behaviors detected in their natural driving environment.