Development and Validity of Norms for Cognitive Dispersion on the Uniform Data Set 3.0 Neuropsychological Battery.

OBJECTIVE: Cognitive dispersion indexes intraindividual variability in performance across a battery of neuropsychological tests. Measures of dispersion show promise as markers of cognitive dyscontrol and everyday functioning difficulties; however, they have limited practical applicability due to a lack of normative data. This study aimed to develop and evaluate normed scores for cognitive dispersion among older adults. METHOD: We analyzed data from 4,283 cognitively normal participants aged ≥50 years from the Uniform Data Set (UDS) 3.0. We describe methods for calculating intraindividual standard deviation (ISD) and coefficient of variation (CoV), as well as associated unadjusted scaled scores and demographically adjusted z-scores. We also examined the ability of ISD and CoV scores to differentiate between cognitively normal individuals (n = 4,283) and those with cognitive impairment due to Lewy body disease (n = 282). RESULTS: We generated normative tables to map raw ISD and CoV scores onto a normal distribution of scaled scores. Cognitive dispersion indices were associated with age, education, and race/ethnicity but not sex. Regression equations were used to develop a freely accessible Excel calculator for deriving demographically adjusted normed scores for ISD and CoV. All measures of dispersion demonstrated excellent diagnostic utility when evaluated by the area under the curve produced from receiver operating characteristic curves. CONCLUSIONS: Results of this study provide evidence for the clinical utility of sample-based and demographically adjusted normative standards for cognitive dispersion on the UDS 3.0. These standards can be used to guide interpretation of intraindividual variability among older adults in clinical and research settings.

The Technology in Caring Questionnaire: Development and Psychometric Properties.

OBJECTIVE: We developed the Technology in Caring Questionnaire (TCQ) to assess the use of technology-based strategies by dementia caregivers. METHODS: One hundred caregivers completed a survey that included TCQ items along with measures of technology proficiency and patient and caregiver-centered outcomes. RESULTS: The final 34-item TCQ scale had adequate to excellent internal consistency (raw Cronbach alpha = 0.75; standardized Cronbach alpha = 0.95; Guttman lambda-6 = 0.97). TCQ scores demonstrated modest convergent associations with scores from measures of smartphone ( r = 0.265, P < 0.01) and computer proficiency ( r = 0.230, P < 0.05) but a strong association with overall technology experience scores ( r = 0.578, P < 0.001). Elevated TCQ scores were associated with reduced informant-reported cognitive symptoms ( B = -0.003, P < 0.05), increased ability of caregivers to find support and information ( B = 0.03, P < 0.001), and increased direct care strain ( B = 0.03, P < 0.05), after controlling for dementia severity and demographics. CONCLUSION: The TCQ has good psychometric properties for the assessment of technology-based care strategies among dementia caregivers. Findings imply that the use of technologies may aid in symptom management and finding support and information but may also increase caregiver strain.

Clinical importance in Alzheimer's disease: effects of anchor agreement and disease severity.

OBJECTIVES: Methods of evaluating clinically meaningful decline are critical in research on Alzheimer's disease. A common method of quantifying clinically meaningful change is to calculate an anchor-based minimal clinically important difference (MCID) score. In this approach, individuals who report a meaningful change serve as the "anchors", and the mean level of change for this group serves as the MCID. In research on Alzheimer's disease, there are several possible anchors, including patients, knowledgeable observers (e.g., a family member), and clinicians. The goal of this study was to examine the extent to which agreement among anchors impacts MCID estimation and whether this relationship is moderated by cognitive severity status. METHODS: Analyses were completed on a longitudinal sample of 2247 adults, aged 50-103, from the Uniform Data Set. Outcome measures included the Montreal Cognitive Assessment, Clinical Dementia Rating-Sum of Boxes, and Functional Activities Questionnaire. RESULTS: For all of the outcomes, the MCID estimate was significantly higher when meaningful decline was endorsed by all of the anchors compared to when there was disagreement among the anchors. In addition, the MCID estimate was higher with increasing severity of cognitive impairment. Finally, cognitive severity status moderated the influence of agreement among anchors on MCID estimation; as disease severity increased, anchor agreement demonstrated less influence on the MCID. CONCLUSIONS: MCID estimates based on one anchor may underestimate meaningful change, and researchers should consider the viewpoints of multiple anchors in constructing MCIDs, particularly in the early stages of cognitive decline.

Internet-Enabled Behaviors in Older Adults During the Pandemic: Patterns of Use, Psychosocial Impacts, and Plans for Continued Utilization.

In response to social distancing measures during the COVID-19 pandemic, there was a need to increase the frequency of internet enabled behaviors (IEBs). To date, little is known about how the pandemic impacted IEBs in older adults, a population that has historically been linked to lower digital literacy and utilization. We administered an online survey between April and July 2021 to 298 adults who were over age 50 (mean age = 73 years; 93.5% non-Hispanic white; 94% smart phone owners; 83.5% retired). Older adults self-reported IEBs for social, shopping, medical, and leisure activities during the pandemic, plans for continued use of these behaviors, and completed measures of psychosocial functioning. 66.8% of respondents reported an overall increase in IEBs during the pandemic, most notably for online meeting attendance. More frequent online meeting use was associated with less depression (r = -0.12, p = .04) and less loneliness (r = -0.14, p = .02). With regard to plans for continued use, 82.5% of the sample reported at least one IEB (M = 2.18, SD = 1.65) that they increased during the pandemic and planned to maintain over time (e.g., online shopping for household goods). Plans for continued use were more likely in participants who used IEBs more overall during the pandemic (r = 0.56, p < .001), and who frequently sought technical support on search engines (r = 0.22, p < .001), or online video sites (r = 0.16, p = .006). In summary, IEBs during the pandemic were associated with favorable psychosocial functioning and expectations for continued use in this sample of predominantly white older adults who had some baseline technological familiarity.

Digital Methods for Performing Daily Tasks Among Older Adults: An Initial Report of Frequency of Use and Perceived Utility.

OBJECTIVE: Digital technologies permit new ways of performing instrumental activities of daily living (iADLs) for older adults, but these approaches are not usually considered in existing iADL measures. The current study investigated how a sample of older adults report using digital versus analog approaches for iADLs. METHOD: 248 older adults completed the Digital and Analog Daily Activities Survey, a newly developed measure of how an individual performs financial, navigation, medication, and other iADLs. RESULTS: The majority of participants reported regularly using digital methods for some iADLs, such as paying bills (67.7%) and using GPS (67.7%). Low digital adopters were older than high adopters (F(2, 245) = 12.24, p < .001), but otherwise the groups did not differ in terms of gender, years of education, or history of neurological disorders. Participants who used digital methods relatively more than analog methods reported greater levels of satisfaction with their approach and fewer daily errors. CONCLUSIONS: Many older adults have adopted digital technologies for supporting daily tasks, which suggests limitations to the validity of current iADL assessments. By capitalizing on existing habits and enriching environments with new technologies, there are opportunities to promote technological reserve in older adults in a manner that sustains daily functioning.

Ecological validity of cognitive fluctuations in dementia with Lewy bodies.

OBJECTIVES: Cognitive fluctuations are a core clinical feature of dementia with Lewy bodies (DLB), but their contribution to the everyday functioning difficulties evident DLB are not well understood. The current study evaluated whether intraindividual variability across a battery of neurocognitive tests (intraindividual variability-dispersion) and daily cognitive fluctuations as measured by informant report are associated with worse daily functioning in DLB. METHODS: The study sample included 97 participants with consensus-defined DLB from the National Alzheimer's Coordinating Center (NACC). Intraindividual variability-dispersion was measured using the coefficient of variation, which divides the standard deviation of an individual's performance scores across 12 normed neurocognitive indices from the NACC neuropsychological battery by that individual's performance mean. Informants reported on daily cognitive fluctuations using the Mayo Fluctuations Scale (MFS) and on daily functioning using the functional activities questionnaire (FAQ). RESULTS: Logistic regression identified a large univariate association of intraindividual variability-dispersion and presence of daily cognitive fluctuations on the MFS (Odds Ratio = 73.27, 95% Confidence Interval = 1.38, 3,895.05). Multiple linear regression demonstrated that higher intraindividual variability-dispersion and presence of daily cognitive fluctuations as assessed by the MFS were significantly and independently related to worse daily functioning (FAQ scores). CONCLUSIONS: Among those with DLB, informant-rated daily cognitive fluctuations and cognitive fluctuations measured in the clinic (as indexed by intraindividual variability-dispersion across a battery of tests) were independently associated with poorer everyday functioning. These data demonstrate ecological validity in measures of cognitive fluctuations in DLB.

A survey of neuropsychological assessment feedback practices among neuropsychologists.

OBJECTIVE: Feedback on neuropsychological assessment is a critical part of clinical practice, but there are few empirical papers on neuropsychological feedback practices. We sought to fill this gap in the literature by surveying practicing neuropsychologists in the United States. Questions addressed how they provide verbal and written feedback to patients and referral sources. Survey questions also addressed billing practices and training in the provision of feedback. METHODS: A survey was developed using Qualtrics XM to survey currently licensed, independently practicing clinical neuropsychologists in the United States about their feedback practices. The survey was completed by 184 individuals. RESULTS: Nearly all respondents reported that they provide verbal feedback to patients, most often in-person, within three weeks following testing. Typically, verbal feedback sessions with patients last 45 min. Verbal feedback was provided to referrals by about half of our sample, typically via a brief phone call. Most participants also reported providing written feedback to both the patient and referring provider, most commonly via the written report within three weeks after testing. Regarding billing, most respondents use neuropsychological testing evaluation codes. The COVID-19 pandemic appeared to have had a limited impact on the perceived effectiveness and quality of verbal feedback sessions. Finally, respondents reported that across major stages of professional development, training in the provision of feedback gradually increased but was considered inadequate by many participants. CONCLUSIONS: Results provide an empirical summary of the "state of current practice" for providing neuropsychological assessment feedback. Further experimental research is needed to develop an evidence-base for effective feedback practices.

Preliminary investigation of the interactive role of physiological arousal and insomnia complaints in gray matter volume alterations in chronic widespread pain.

STUDY OBJECTIVES: Brain regions involved in insomnia and chronic pain are overlapping and diffuse. The interactive role of physiological arousal in associations between insomnia symptoms and neural regions is unknown. This preliminary study examined whether arousal interacted with sleep in associations with gray matter volume of frontal (dorsolateral prefrontal cortex, anterior cingulate cortex) and temporal (right/left hippocampus) regions in adults with chronic widespread pain and insomnia complaints. METHODS: Forty-seven adults with chronic widespread pain and insomnia (mean age = 46.00, standard deviation = 13.88, 89% women) completed 14 daily diaries measuring sleep onset latency (SOL), wake time after sleep onset, and total sleep time (TST), as well as Holter monitor assessments of heart rate variability (measuring physiological arousal), and magnetic resonance imaging. Multiple regressions examined whether average SOL, wake time after sleep onset, or TST were independently or interactively (with arousal/heart rate variability) associated with dorsolateral prefrontal cortex, anterior cingulate cortex, and left/right hippocampus gray matter volumes. RESULTS: Shorter TST was associated with lower right hippocampus volume. TST also interacted with arousal in its association with right hippocampal volume, Specifically, shorter TST was associated with lower volume at highest and average arousal levels. SOL interacted with arousal in its association with anterior cingulate cortex volume, such that, among individuals with lowest arousal, longer SOL was associated with lower volume. CONCLUSIONS: Preliminary findings highlight the interactive roles of physiological arousal and insomnia symptoms in associations with neural structure in chronic widespread pain and insomnia. Individuals with the highest physiological arousal may be particularly vulnerable to the impact of shorter TST on hippocampal volume loss. Reducing SOL may only impact anterior cingulate cortex volume in those with lower physiological arousal. CITATION: Curtis AF, Nair N, Hayse B, et al. Preliminary investigation of the interactive role of physiological arousal and insomnia complaints in gray matter volume alterations in chronic widespread pain. J Clin Sleep Med. 2024;20(2):293-302.

Limited connectedness of spontaneous speech may be a marker of dementia due to Alzheimer's disease.

The study evaluated the connectedness of spontaneous speech production in individuals with dementia as a potential predictor of dementia severity. Data were derived from the baseline sample of 143 individuals with dementia in the English Pitt corpus. Dementia severity was assessed via the Mini Mental Status Exam, the Mattis Dementia Rating Scale, and the Blessed Dementia Scale. Language abilities were evaluated using verbal fluency and picture description tasks. Graph analysis was carried out for the picture description task using the computational tool SpeechGraphs to calculate connectedness. Results demonstrated that higher educational attainment, higher verbal fluency and strongly-connected spontaneous speech were associated with better cognitive function. Results suggest that automated language processing approaches, such as graph structure analysis, may provide a faster and ecologically valid method of detecting dementia symptoms.

Career development in pragmatic clinical trials to improve care for people living with dementia.

The growing number of people living with dementia (PLWD) requires a coordinated clinical response to deliver pragmatic, evidence-based interventions in frontline care settings. However, infrastructure to support such a response is lacking. Moreover, there are too few researchers conducting rigorous embedded pragmatic clinical trials (ePCTs) to make the vision of high quality, widely accessible dementia care a reality. National Institute on Aging (NIA) Imbedded Pragmatic Alzheimer's disease and Related Dementias Clinical Trials (IMPACT) Collaboratory seeks to improve the pipeline of early career researchers qualified to lead ePCTs by funding career development awards. Even with support from the Collaboratory, awardees face practical and methodological challenges to success, recently exacerbated by the COVID-19 pandemic. We first describe the training opportunities and support network for the IMPACT CDA recipients. This report then describes the unique career development challenges faced by early-career researchers involved in ePCTs for dementia care. Topics addressed include challenges in establishing a laboratory, academic promotion, mentoring and professional development, and work-life balance. Concrete suggestions to address these challenges are offered for early-career investigators, their mentors, and their supporting institutions. While some of these challenges are faced by researchers in other fields, this report seeks to provide a roadmap for expanding the work of the IMPACT Collaboratory and initiating future efforts to recruit, train, and retain talented early-career researchers involved in ePCTs for dementia care.

Recent Advances in Neuropsychological Test Interpretation for Clinical Practice.

Much attention in the field of clinical neuropsychology has focused on adapting to the modern healthcare environment by advancing telehealth and promoting technological innovation in assessment. Perhaps as important (but less discussed) are advances in the development and interpretation of normative neuropsychological test data. These techniques can yield improvement in diagnostic decision-making and treatment planning with little additional cost. Brooks and colleagues (Can Psychol 50: 196-209, 2009) eloquently summarized best practices in normative data creation and interpretation, providing a practical overview of norm development, measurement error, the base rates of low scores, and methods for assessing change. Since the publication of this seminal work, there have been several important advances in research on development and interpretation of normative neuropsychological test data, which may be less familiar to the practicing clinician. Specifically, we provide a review of the literature on regression-based normed scores, item response theory, multivariate base rates, summary/factor scores, cognitive intraindividual variability, and measuring change over time. For each topic, we include (1) an overview of the method, (2) a rapid review of the recent literature, (3) a relevant case example, and (4) a discussion of limitations and controversies. Our goal was to provide a primer for use of normative neuropsychological test data in neuropsychological practice.

The impact of technology-based compensatory behaviors on subjective cognitive decline in older adults with a family history of dementia.

The current study examined whether greater use of technology to help with daily tasks is associated with less subjective cognitive decline (SCD), especially in individuals with a family history of Alzheimer's disease (AD). Individuals over the age of 50 (n = 102; age range 50-85) completed surveys about their digital and analog approaches to daily tasks, physical activity, and SCD. Participants with and without family histories of AD were matched on age, education, sex, and family history of AD using the R package MatchIt. There was no main effect of technology-based behavioral strategies on SCD (p = 0.259). However, a family history of AD moderated the association between technology use and SCD even when controlling for another protective lifestyle factor, physical activity. In individuals with a family history of AD, more reliance on technology-based behavioral strategies was associated with less SCD (p = 0.018), but this relationship was not significant in individuals without family history of AD (p = 0.511). Our findings suggest that technology-based behavioral strategies are associated with less SCD in individuals with a family history of AD, independent of another protective lifestyle factor. Future recommendations provided by healthcare providers to address SCD in cognitively unimpaired older adults might include focusing on technological assistance.

Demographically-adjusted normative data among Latinos for the version 3 of the Alzheimer's Disease Centers' Neuropsychological Test Battery in the Uniform Data Set.

INTRODUCTION: We developed demographically-adjusted normative data for Spanish- and English-speaking Latinos on the Version 3.0 of the National Alzheimer's Coordinating Center Uniform Data Set Neuropsychological Battery (UDS3-NB). METHODS: Healthy Latino adults (N = 437) age 50-94 (191 Spanish- and 246 English-speaking) enrolled in Alzheimer's Disease Research Centers completed the UDS3-NB in their preferred language. Normative data were developed via multiple linear regression models on UDS3-NB raw scores stratified by language group with terms for demographic characteristics (age, years of formal education, and sex). RESULTS: Younger age and more years of education were associated with better performance on most tests in both language groups, with education being particularly influential on raw scores among Spanish-speakers. Sex effects varied across tests and language groups. DISCUSSION: These normative data are a crucial step toward improving diagnostic accuracy of the UDS3-NB for neurocognitive disorders among Latinos in the United States and addressing disparities in Alzheimer's disease and related dementias. HIGHLIGHTS: We developed normative data on the UDS3-NB for Latinos in the US ages 50-94. Younger age and more years of education were linked to better raw scores in several cognitive tests. Education was particularly influential on raw scores among Spanish-speakers. Sex effects varied across tests and between English- and Spanish-speaking Latinos. These normative data might improve diagnostic accuracy of the UDS3-NB among Latinos.

Technology use and subjective cognitive concerns in older adults.

OBJECTIVES: How technology impacts the day to day cognitive functioning of older adults is a matter of some debate. On the one hand, the use of technologies such as smartphones and social media, may lead to more subjective cognitive concerns (SCC) by promoting distractibility and reliance on devices to perform memory tasks. However, continued digital engagement in older adults may also be related to better cognitive functioning. Given these competing viewpoints, our study evaluated if frequency of digital device use was associated with greater or less subjective cognitive concerns. METHOD: Participants were 219 adults over the age of 65 (mean age =75 years) who had internet access. Measures assessing frequency of digital device use along with SCC were administered. Hierarchical multiple regression was used to gage association between frequency of device use and SCC, controlling for relevant demographic and lifestyle factors. RESULTS: Increased frequency of digital device use was associated with less SCC, over and above the influence of demographic factors, across cognitive (but especially in executive) domains. This effect was observed for general device usage, with no statistically significant associations were observed between texting/video call, social media use and SCC. DISCUSSION: Results were broadly consistent with the technological reserve hypothesis in that digital engagement was associated with better experienced cognitive functioning in older adults. While device use may contribute to distractibility in certain cases, the current results add to a burgeoning literature that digital engagement may be a protective factor for cognitive changes with age.

Examining racial disparities in the diagnosis of mild cognitive impairment.

Black individuals are less likely to receive an accurate diagnosis of mild cognitive impairment (MCI) than their White counterparts, possibly because diagnoses are typically made by a physician, often without reference to objective neuropsychological test data. We examined racial differences in actuarial MCI diagnoses among individuals diagnosed with MCI via semi-structured clinical interview (the Clinical Dementia Rating) to examine for possible biases in the diagnostic process. Participants were drawn from the National Alzheimer's Coordinating Center Uniform Data Set and included 491 individuals self-identifying as Black and 2,818 individuals self-identifying as White. Chi-square tests were used to examine racial differences in rates of low scores for each cognitive test (domains assessed included attention, processing speed/executive functioning, memory, language, and visual skills). Next, we tested for racial differences in probability of meeting actuarial criteria for MCI by race. Compared to Black participants diagnosed with MCI via clinical interview, White individuals diagnosed with MCI via clinical interview demonstrated significantly higher rates of low demographically-adjusted z-scores on tests of memory, attention, processing speed, and verbal fluency. Furthermore, White individuals were significantly more likely to meet actuarial criteria for MCI (71.60%) than Black individuals (57.90%). Results suggest there may be bias in MCI classification based on semi-structured interview, leading to over diagnosis among Black individuals and/or under diagnosis among White individuals. Examination of neuropsychological test data and use of actuarial approaches may reduce racial disparities in the diagnosis of MCI. Nonetheless, issues related to race-based norming and differential symptom presentations complicate interpretation of results.

Specific learning disorder in mathematics and moyamoya disease: A case report.

Moyamoya disease (MMD) is a rare neurological condition that causes impaired blood flow to the brain, transient ischemic attacks or strokes, and accompanying cognitive impairments, especially in executive functioning. There is little data on the impact of this rare condition on academic outcomes in late childhood and adolescence. Here, we present the case of Ms. X, a 17-year-old white female diagnosed with MMD, who presented with evidence of a specific learning disorder (SLD) in mathematics. Ms. X was diagnosed with MMD at 6 years old and underwent revascularization surgery. Though she recovered well and progressed adequately in home schooling, she and her mother noticed a decline in memory and academic performance around 16 years old, prompting a neuropsychological evaluation. Cognitive testing revealed low average overall cognitive abilities with impaired planning and organizational skills. While her reading and spelling skills were consistent with her 10th grade academic level, she scored in the 1st percentile on the WRAT-5 Math Computation section, and her mathematical skills were estimated to be at a 2nd grade level. This case adds to the literature by documenting a specific area of academic deficit in an adolescent with MMD. The case highlights that individuals with MMD, especially those with similar executive deficits, may experience selective learning challenges in mathematics. Children with MMD may benefit from specialized academic services and interventions in specific areas of difficulty.

The impact of conventional versus robust norming on cognitive characterization and clinical classification of MCI and dementia.

We examined the impact of conventional versus robust normative approaches on cognitive characterization and clinical classification of MCI versus dementia. The sample included participants from the National Alzheimer's Coordinating Center Uniform Data Set. Separate demographically adjusted z-scores for cognitive tests were derived from conventional (n = 4273) and robust (n = 602) normative groups. To assess the impact of deriving scores from a conventional versus robust normative group on cognitive characterization, we examined likelihood of having a low score on each neuropsychological test. Next, we created receiver operating characteristic (ROC) curves for the ability of normed scores derived from each normative group to differentiate between MCI (n = 3570) and dementia (n = 1564). We examined the impact of choice of normative group on classification accuracy by comparing sensitivity and specificity values and areas under the curves (AUC). Compared with using a conventional normative group, using a robust normative group resulted in a higher likelihood of low cognitive scores for individuals classified with MCI and dementia. Comparison of the classification accuracy for distinguishing MCI from dementia did not suggest a statistically significant advantage for either normative approach (Z = -0.29, p = .77; AUC = 0.86 for conventional and AUC = 0.86 for robust). In summary, these results indicate that using a robust normative group increases the likelihood of characterizing cognitive performance as low. However, there is not a clear advantage of using a robust over a conventional normative group when differentiating between MCI and dementia.

Psychometric properties of the Autonomic Symptoms Checklist in the Lewy body disease module of the uniform dataset.

INTRODUCTION: Autonomic dysfunction is an important feature of Lewy Body Dementia (DLB), but measurement of autonomic symptoms has been limited in both previous research and clinical practice. Accurate measurement of autonomic dysfunction has the potential to improve our understanding of the course and progression of DLB, given that autonomic symptoms typically precede cognitive impairment and are associated with functional impairment. The primary aim of this study was to examine the psychometric properties of the two versions (3.0 and 3.1) of the NACC LBD-module Autonomic Symptom Checklist (ASC). METHODS: Psychometric analyses of the ASC (internal consistency, reliability, factor structure, and validity) were conducted on data acquired from 245 individuals with DLB from the NACC database. ASC V3.0 was contrasted on these attributes to V3.1. RESULTS: Results suggested an underlying factor structure for the ASC, and confirmatory factor analysis (CFA) revealed 3 factors, which generally aligned with discrete autonomic systems. The ASC V3.0 and CFA-identified scales were comparable in terms of reliability, which were both improved relative to the ASC V3.1. In terms of ecological validity, CFA-identified items related to gastrointestinal/thermoregulation symptoms were significantly more associated with functional outcomes compared to the unitary ASC. CONCLUSION: Findings underscore the importance of differentiation within the autonomic system. Future research into autonomic symptom classes and lab-based pathophysiological measurement of autonomic dysfunction in DLB has the potential to support early identification and inform treatment planning.

Dispersion-based cognitive intra-individual variability in dementia with Lewy bodies.

OBJECTIVE: Cognitive fluctuations are characteristic of dementia with Lewy bodies (DLB) but challenging to measure. Dispersion-based intra-individual variability (IIV-d) captures neurocognitive performance fluctuations across a test battery and may be sensitive to cognitive fluctuations but has not been studied in DLB. METHOD: We report on 5,976 participants that completed the uniform data set 3.0 neuropsychological battery (UDS3NB). IIV-d was calculated via the intra-individual standard deviation across 12 primary UDS3NB indicators. Separate models using mean USD3NB score and the Montreal cognitive assessment (MoCA) total score tested the reproducibility of the incremental value of IIV-d over-and-above global cognition. Binary logistic regressions tested whether IIV-d could classify individuals with and without clinician-rated cognitive fluctuations. Multinomial logistic regressions tested whether IIV-d could differentiate participants with DLB, participants with Alzheimer's disease (AD), and participants with healthy cognition (CH), as well as the incremental diagnostic utility of IIV-d over-and-above clinician-rated cognitive fluctuations. RESULTS: IIV-d exhibited large univariate associations with clinician-rated and non-clinician-informant reported cognitive fluctuations, which persisted when adjusting for MoCA but not the full battery mean. Of diagnostic relevance, greater IIV-d was consistently associated with DLB and AD relative to CH over-and-above global cognition and clinician-rated cognitive fluctuations. Greater IIV-d was less consistently associated with an increased probability of DLB relative to AD when controlling for global cognition. CONCLUSIONS: IIV-d accurately differentiates DLB from CH over-and-above global cognition and clinician-rated cognitive fluctuations. IIV-d may supplement a thorough clinical interview of cognitive fluctuations and serve as a standardized performance-based indicator of this transdiagnostic phenomenon. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Comparison of Azure Kinect overground gait spatiotemporal parameters to marker based optical motion capture.

BACKGROUND: Instrumented measurement of spatiotemporal parameters during walking can provide valuable information on an individual's overall function and health. Efficient, inexpensive, and accurate measurement of overground walking spatiotemporal parameters would be a critical component of providing point-of-care assessments of gait function, concussion recovery, fall-risk, and cognitive decline. Depth cameras combined with skeleton pose tracking algorithms, such as the Microsoft Kinect with body tracking software, have been used to measure walking spatiotemporal parameters. However, the ability of the latest generation Microsoft Kinect sensor, the Azure Kinect, to accurately measure overground walking spatiotemporal parameters has not been evaluated in the literature. RESEARCH QUESTION: The purpose of this work was to compare overground walking spatiotemporal parameters measurements from a 12 camera Vicon optical motion capture system to measurements of a single Azure Kinect with body tracking SDK (software development kit). METHODS: Spatiotemporal parameters of overground walking were simultaneously collected on twenty young healthy participants. Stride length, stride time, step length and step width were derived from ankle joint center locations and measurements from the two instruments were compared using descriptive statistics, scatter plots, Pearson correlation analyses, and Bland-Altman analyses. RESULTS: Pearson correlation coefficients were greater than 0.87 for all spatiotemporal parameters with most parameters demonstrating very strong (> 0.9) agreement. The mean of the differences for stride length between measurements was 35.6 mm for the left limb and 39.1 mm for the right limb, both of which are less than 3% of average stride length. Mean of the differences for step width and stride time were less than 2% and 1% of their averages respectively. SIGNIFICANCE: A single Microsoft Azure Kinect with body tracking SDK can provide clinically relevant measurement of walking spatiotemporal parameters, providing accessible and objective measurements that can improve clinical decision making across a variety of patient populations.