"Forgetting to remember" in Huntington's disease: a study of laboratory, semi-naturalistic, and self-perceptions of prospective memory

Factor Structure of the Memory for Intentions Test (MIsT): A Conceptual Replication in Older Adults and People with HIV Disease

OBJECTIVE

The Memory for Intentions Test (MIsT) is a clinical measure of prospective memory that has strong evidence for convergent, discriminative, and ecological validity. This study uses a conceptual replication design to evaluate the latent structure of the MIsT in two parallel samples who commonly experience prospective memory deficits: older adults and people living with HIV disease.

PARTICIPANTS AND METHODS

Study participants included 303 people with HIV disease (ages 18-67) and 267 community-dwelling older adults (ages 50-91). Confirmatory factor analyses of the MIsT were conducted separately in each sample. We evaluated a one-factor model, as well as three two-factor models with the MIsT items loading onto each factor based on cue type, delay interval, or response modality.

RESULTS

The one-factor model provided the best (and most parsimonious) fit to the data in both study samples. All two-factor models also demonstrated good fit statistics, although correlations between the two factors in each model were high and none of the two-factor models provided a significantly better fit than the one-factor model.

CONCLUSIONS

Results of this conceptual replication study provide support for a robust factor structure of the MIsT across older adults and people with HIV disease. A total score for the MIsT provides the most parsimonious solution, although available evidence and theory also support the potential use of subscales (e.g., cue type). Future studies of the MIsT would be useful to determine its psychometrics in different clinical populations and across demographic factors (e.g., race/ethnicity).

Montreal cognitive assessment for evaluating cognitive impairment in Huntington's disease: a systematic review

OBJECTIVE

This study aims to systematically review evidence of the accuracy of the Montreal Cognitive Assessment (MoCA) for evaluating the presence of cognitive impairment in patients with Huntington's disease (HD) and to outline the quality and quantity of research evidence available about the use of the MoCA in this population.

METHODS

We conducted a systematic literature review, searching four databases from inception until April 2020.

RESULTS

We identified 26 studies that met the inclusion criteria: two case-control studies comparing the MoCA to a battery of tests, three studies comparing MoCA to Mini-Mental State Examination, two studies estimating the prevalence of cognitive impairment in individuals with HD and 19 studies or clinical trials in which the MoCA was used as an instrument for the cognitive assessment of participants with HD. We found no cross-sectional studies in which participants received the index test (MoCA) and a reference standard diagnostic assessment composed of an extensive neuropsychological battery. The publication period ranged from 2010 to 2020.

CONCLUSIONS

In patients with HD, the MoCA provides information about disturbances in general cognitive function. Even if the MoCA demonstrated good sensitivity and specificity when used at the recommended threshold score of 26, further cross-sectional studies are required to examine the optimum cutoff score for detecting cognitive impairments in patients with HD. Moreover, more studies are necessary to determine whether the MoCA adequately assesses cognitive status in individuals with HD.

Longitudinal declines in event-based, but not time-based, prospective memory among community-dwelling older adults

Age-related deficits in prospective memory (PM) are well established, but it is not known whether PM is stable over time among older adults. In this study, 271 community-dwelling older adults underwent abaseline neuropsychological evaluation and up to three follow-up visits, approximately 2.4 years apart. Mixed effects linear longitudinal models revealed small, but significant linear declines and between-subjects variability in event-based PM performance. There were no changes in performance on measures of time-based PM, retrospective memory, or executive functions. Changes in event-based PM were not associated with age, retrospective memory, executive functions, or everyday functioning. Among older adults, event-based PM appears to be more susceptible to linear declines than does time-based PM, which future research might examine with regard to the possible underlying cognitive mechanisms of cue encoding, monitoring, detection, and retrieval processes.

Prospective memory impairment in neurological disorders: implications and management

Prospective memory is a core neurocognitive ability that refers to memory for future intentions, such as remembering to take medications and to switch off appliances. Any breakdown in prospective memory, therefore, has serious implications for the ability to function independently in everyday life. In many neurological disorders, including Parkinson disease and dementia, prospective memory deficits are common even in the earliest stages and typically become more severe with disease progression. Consequently, clinical assessment of prospective memory is of critical importance. This article provides an overview of the various manifestations and neural bases of prospective memory deficits. To facilitate clinical decision-making, validated measures of this construct are identified and their suitability for clinical practice is discussed, focusing in particular on clinical sensitivity and psychometric properties. The article concludes by reviewing the approaches that can be used to rehabilitate different types of prospective memory impairment, and algorithms to guide the evaluation and treatment of these impairments are provided.

Cognition, function and awareness of disease impact in early Parkinson's and Huntington's disease

Purpose: Patients with Parkinson's and Huntington's Disease (PD and HD) present impairments in cognitively challenging everyday activities. This study contrasts these two basal ganglia disorders on the ability to perform daily life- like tasks and their level of awareness regarding the disease impact on function.Methods: 19 controls, 10 early-onset PD, 20 early stage PD, and 15 early manifest HD patients were compared in the "EcoKitchen," a virtual reality task with increasing executive load, the "Behavioural Assessment of Dysexecutive Syndrome battery - BADS," and "The Adults and Older Adults Functional Assessment Inventory - IAFAI," a self-report functional questionnaire. The EcoKitchen clinical correlates were investigated.Results: All clinical groups presented slower EcoKitchen performance than controls, however, only HD patients showed decreased accuracy. HD and PD patients exhibited reduced BADS scores compared to the other study participants. Importantly, on the IAFAI, PD patients signalled more physically related incapacities and HD patients indicated more cognitively related incapacities. Accordingly, the EcoKitchen performance was significantly associated with PD motor symptom severity.Conclusions: Our findings suggest differential disease impact on cognition and function across PD and HD patients, with preserved awareness regarding disease- related functional sequelae. These observations have important implications for clinical management, research and rehabilitation.Implications for rehabilitationPatients with early stage Parkinson's and Huntington's disease have diagnosis-specific impairments in the performance of executively demanding everyday activities and, yet, show preserved awareness about the disease impact on their daily life.An active involvement of patients in the rehabilitation process should be encouraged, as their appraisal of the disease effects can help on practical decisions about meaningful targets for intervention, vocational choices, quality-of-life issues and/or specific everyday skills to boost.The EcoKitchen, a non-immersive virtual reality task, can detect and quantify early deficits in everyday-like tasks and is therefore a valuable tool for assessing the effects of rehabilitation strategies on the functional cognition of these patients.Rehabilitation efforts in the mild stages of Parkinson's and Huntington's disease should be aware of greater time needs from the patients in the performance of daily life tasks, target executive skills, and give a more prominent role to patients in symptoms report and management.

Comparing different tests to detect early manifestation of prospective memory decline in aging

Objective: Prospective memory (PM) is the ability to remember to perform future intentions. Previous studies have demonstrated that, compared to a younger cohort, healthy older adults have impairments in PM. Considering the importance of early detection of age-related PM decline, the present study aims to compare the performance of healthy older adults using three well-known PM tests commonly used in clinical settings.Method: In the present study, we tested 70 older adults (65-95 years old) using the Cambridge Prospective Memory Test (CAMPROMPT), the Memory for Intentions Screening Test (MIST) and the Royal Prince Alfred Prospective Memory Test (RPA-ProMem). In order to compare performance across tests and the interaction between age and cues, we performed a linear mixed model with random intercept and random slopes. Moreover, additional mixed models with random intercept were run for analyzing the additional information provided by MIST and RPA-ProMem regarding delay responses, response modality effects and type of errors committed.Results: Our data showed a drop in PM performance as age increased detected by all three tests. Furthermore, CAMPROMPT was the most sensitive test to identify differences in PM for event-and time-based cues, at least for participants with 65-77 years old. When data were analyzed in term of delay responses, participants were more accurate for 2 min delay (MIST) and 30 in delay (RPA-ProMem). Participants were less accurate when response modality was "verbal" compared to "action" (MIST) and made more PM errors as age increased.Conclusions: Overall, the study provides important information regarding age-related PM decline and can help researchers as well as clinicians in deciding the preferred test to evaluate PM performance.

Medication Management Capacity and Its Neurocognitive Correlates in Huntington's Disease

OBJECTIVE

Although medication management is a necessary daily activity for individuals with Huntington's disease (HD), medication management abilities and their relation to cognitive functioning have not been evaluated.

METHOD

Twenty individuals with HD and 20 healthy adults (HA) completed the Medication Management Abilities Assessment (MMAA). Individuals with HD also completed a self-report medication management measure and neuropsychological tests assessing executive function, retrospective memory, and prospective memory.

RESULTS

Individuals with HD performed significantly poorer and made more undertaking errors on the MMAA as compared to HA. No group differences were found in overtaking errors. In the HD group, significant associations were found between undertaking errors and perceived medication management ability as well as between MMAA task performance and measures assessing prospective memory and executive functions.

CONCLUSIONS

Medication management capacity was negatively affected in individuals with HD and may be associated with difficulty remembering to take medications in the future.

A Novel Ecological Approach Reveals Early Executive Function Impairments in Huntington's Disease

Introduction: Impairments in executive functions are common in neurogenetic disorders such as Huntington's disease (HD) and are thought to significantly influence the patient's functional status. Reliable tools with higher ecological validity that can assess and predict the impact of executive dysfunction in daily-life performance are needed. This study aimed to develop and validate a novel non-immersive virtual reality task ("EcoKitchen") created with the purpose of capturing cognitive and functional changes shown by HD carriers without clinical manifestations of the disease (Premanifest HD), in a more realistic setting. Materials and Methods: We designed a virtual reality task with three blocks of increasing executive load. The performance of three groups (Controls, CTRL; Premanifest HD individuals, HP; Early Manifest HD patients, HD) was compared in four main components of the study protocol: the EcoKitchen; a subjective (self-report) measure - "The Adults and Older Adults Functional Assessment Inventory (IAFAI)"; the "Behavioural Assessment of Dysexecutive Syndrome battery (BADS)"; and a conventional neuropsychological test battery. We also examined statistical associations between EcoKitchen and the other executive, functional and clinical measures used. Results: The HD group showed deficits in all the assessment methods used. In contrast, the HP group was only found to be impaired in the EcoKitchen task, particularly in the most cognitively demanding blocks, where they showed a higher number of errors compared to the CTRL group. Statistically significant correlations were identified between the EcoKitchen, measures of the other assessment tools, and HD clinical features. Discussion: The EcoKitchen task, developed as an ecological executive function assessment tool, was found to be sensitive to early deficits in this domain. Critically, in premanifest HD individuals, it identifies dysfunction prior to symptom onset. Further it adds a potential tool for diagnosis and management of the patients' real-life problems.

Development and reliability of the Prospective Memory Assessment for Children & Youth (PROMACY): A preliminary study in a nonclinical sample

Prospective memory (PM), "remembering to remember," has been linked to important functional outcomes in adults. Studies of PM in children and adolescents would benefit from the development and validation of developmentally appropriate clinical measures with known psychometric properties. The Prospective Memory Assessment for Children & Youth (PROMACY), a performance-based measure of PM, was developed for the Pediatric HIV/AIDS Cohort Study Adolescent Master Protocol, Memory and Executive Functioning Substudy, and includes Summary, Time-, and Event-based scores derived from eight trials with an ongoing word search task. Fifty-four healthy perinatally HIV-exposed, uninfected children and youth, mean age 13 years, 54% female, 76% Black/non-Hispanic, and 61% impoverished were included in this psychometric analysis. PROMACY Summary Scores demonstrated low, but broadly acceptable internal consistency as measured by Cronbach's alpha and Spearman-Brown. Better PROMACY performance was associated with older age, but no other demographic factors. Generally medium-sized correlations were observed between the PROMACY Summary Score and standard clinical measures of retrospective memory, working memory, executive functions, and IQ. Findings from this preliminary psychometric study of nonclinical children and youth provide cautious support for the internal consistency and construct validity of PROMACY's Summary Score that awaits replication and extension in larger samples of healthy children, youth and clinical populations.

The Neuropsychology of Huntington's Disease

Huntington's disease is an inherited, degenerative brain disease, characterized by involuntary movements, cognitive disorder and neuropsychiatric change. Men and women are affected equally. Symptoms emerge at around 40 years, although there is wide variation. A rare juvenile form has onset in childhood or adolescence. The evolution of disease is insidious and structural and functional brain changes may be present more than a decade before symptoms and signs become manifest. The earliest site of pathology is the striatum and neuroimaging measures of striatal change correlate with neurological and cognitive markers of disease. Chorea and other aspects of the movement disorder are the most visible aspect of the disease. However, non-motor features have greatest affect on functional independence and quality of life, so require recognition and management. The evidence-base for non-pharmacological treatments in Huntington's disease is currently limited, but recent intervention studies are encouraging.

The role of the amygdala during emotional processing in Huntington's disease: from pre-manifest to late stage disease

BACKGROUND

Deficits in emotional processing can be detected in the pre-manifest stage of Huntington's disease and negative emotion recognition has been identified as a predictor of clinical diagnosis. The underlying neuropathological correlates of such deficits are typically established using correlative structural MRI studies. This approach does not take into consideration the impact of disruption to the complex interactions between multiple brain circuits on emotional processing. Therefore, exploration of the neural substrates of emotional processing in pre-manifest HD using fMRI connectivity analysis may be a useful way of evaluating the way brain regions interrelate in the period prior to diagnosis.

METHODS

We investigated the impact of predicted time to disease onset on brain activation when participants were exposed to pictures of faces with angry and neutral expressions, in 20 pre-manifest HD gene carriers and 23 healthy controls. On the basis of the results of this initial study went on to look at amygdala dependent cognitive performance in 79 Huntington's disease patients from a cross-section of disease stages (pre-manifest to late disease) and 26 healthy controls, using a validated theory of mind task: "the Reading the Mind in the Eyes Test" which has been previously been shown to be amygdala dependent.

RESULTS

Psychophysiological interaction analysis identified reduced connectivity between the left amygdala and right fusiform facial area in pre-manifest HD gene carriers compared to controls when viewing angry compared to neutral faces. Change in PPI connectivity scores correlated with predicted time to disease onset (r=0.45, p<0.05). Furthermore, performance on the "Reading the Mind in the Eyes Test" correlated negatively with proximity to disease onset and became progressively worse with each stage of disease.

CONCLUSION

Abnormalities in the neural networks underlying social cognition and emotional processing can be detected prior to clinical diagnosis in Huntington's disease. Connectivity between the amygdala and other brain regions is impacted by the disease process in pre-manifest HD and may therefore be a useful way of identifying participants who are approaching a clinical diagnosis. Furthermore, the "Reading the Mind in the Eyes Test" is a surrogate measure of amygdala function that is clinically useful across the entire cross-section of disease stages in HD.

Assessing impairment of executive function and psychomotor speed in premanifest and manifest Huntington's disease gene-expansion carriers

Executive functions (EF) and psychomotor speed (PMS) has been widely studied in Huntington's disease (HD). Most studies have focused on finding markers of disease progression by comparing group means at different disease stages. Our aim was to investigate performances on nine measures of EF and PMS in a group of premanifest and manifest HD-gene expansion carriers and to investigate which measures were most sensitive for assessment of individual patients by analyzing frequencies of impaired performances relative to healthy controls. We recruited HD gene-expansion carriers, 48 manifest and 50 premanifest and as controls 39 healthy gene-expansion negative individuals. All participants underwent neurological examination and neuropsychological testing with nine cognitive measures. The frequency of impairment was investigated using cutoff scores. In group comparisons the manifest HD gene-expansion carriers scored significantly worse than controls on all tests and in classification of individual scores the majority of scores were classified as probably impaired (10th percentile) or impaired (5th percentile) with Symbol Digit Modalities Test (SDMT) being the most frequently impaired. Group comparisons of premanifest HD gene-expansion carriers and healthy controls showed significant differences on SDMT and Alternating fluency tests. Nevertheless the frequencies of probably impaired and impaired scores on individual tests were markedly higher for Alternating and Lexical fluency tests than for SDMT. We found distinct group differences in frequency of impairment on measures of EF and PMS in manifest and premanifest HD gene-expansion carriers. Our results indicate to what degree these measures can be expected to be clinically impaired.