Cognitive change in patients with Huntington disease on the Repeatable Battery for the Assessment of Neuropsychological Status

Specific contribution of cognitive and motor impairments with functional capacity and dependence in Huntington's disease

BACKGROUND

Huntington's disease (HD) leads to increasing dependence. Unlike psychiatric disorders, motor and cognitive deficits evolve progressively over time. Understanding their specific impact on daily activities is crucial for preserving autonomy. However, because cognitive tasks in HD rely on motor functions, and motor tasks demand cognitive processing, disentangling their specific impact remains a challenge.

OBJECTIVE

To identify the specific contribution of cognitive and motor impairments on global functional capacity, basic and instrumental activities of daily living (ADL/IADL), and work-related activities (WRA) in HD.

METHODS

158 HD mutation carriers, enrolled in the BioHD (NCT01412125) and RepairHD (NCT03119246) studies, were evaluated with the Unified Huntington's Disease Rating Scale and the SelfCog. The SelfCog assesses motor processing separately from memory, language, executive functions and visuospatial processing. Linear regressions were fitted to assess how functional capacity declined with motor and cognition impairments. Odds of dependence in ADLs, IADLs and WRAs were estimated using logistic regressions.

RESULTS

Cognitive and motor performance were independently associated with functional capacities, though motor performance showed a stronger association than cognitive performance. Decline of all SelfCog cognitive domains contributed to functional decline, with stronger association with global and executive scores compared to language, visuospatial, and memory domains. Higher global and executive deficits were associated with an increased risk of dependence in ADLs, IADLs, and WRAs.

CONCLUSION

The independent contributions of motor, followed by cognitive-mainly executive-functions to functional decline suggest targeted interventions to preserve autonomy and quality of life in HD.

Cognitive impairment predicts medication discrepancies in Huntington's Disease: patient self-report compared to pharmacy records

BACKGROUND

Proper medication reconciliation (= comparing the accuracy of patient-reported medication use with pharmacy records) could prevent potentially dangerous situations such as drug-drug interactions and hospitalization. This is particularly important when patients rely on multiple medications, such as in neurodegenerative disorders like Huntington's Disease (HD). Currently, it is unknown how often medication discrepancies occur in HD patients and which factors contribute to the discrepancies.

OBJECTIVE

Identify prognostic factors of medication discrepancies in HD, using patient-reported medication use and local pharmacy records.

METHODS

With 134 pre- and manifest HD patients, we performed a multivariable logistic regression analysis with medication discrepancy as dependent variable (pharmacy records as reference value) and sex, CAP score, disease status (pre- or manifest HD), number of concomitant medications taken, presence of an informal caregiver, Unified Huntington's Disease Rating Scale-Total Functioning Capacity, unified cognitive Z-score and Problem Behaviors Assessment-short characteristic scores for depression, anxiety, and apathy as independent variables.

RESULTS

Medication discrepancies were reported frequently, both in premanifest (43.2%) and manifest HD subjects (36.7%). Impaired cognition significantly predicted medication discrepancies (beta = -0.688, SE 0.27, p = 0.011). All other variables were non-significant.

CONCLUSIONS

Regardless of HD disease status and stage, patient self-reported medication use is not a reliable source, especially in those with impaired cognitive function. The presence of an informal caregiver and the absence of polypharmacy, depression, anxiety and apathy do not influence self-reported medication accuracy. Objective verification of medication use with HD patients' local pharmacy is recommended.

TRIAL REGISTRATION NUMBER

ICTRP-NL-OMON55123, HD-med, registered 26-Nov-2019.

Measuring cognitive impairment and monitoring cognitive decline in Huntington's disease: a comparison of assessment instruments

BACKGROUND

Progressive cognitive decline is an inevitable feature of Huntington's disease (HD) but specific criteria and instruments are still insufficiently developed to reliably classify patients into categories of cognitive severity and to monitor the progression of cognitive impairment.

METHODS

We collected data from a cohort of 180 positive gene-carriers: 33 with premanifest HD and 147 with manifest HD. Using a specifically developed gold-standard for cognitive status we classified participants into those with normal cognition, those with mild cognitive impairment, and those with dementia. We administered the Parkinson's Disease-Cognitive Rating Scale (PD-CRS), the MMSE and the UHDRS cogscore at baseline, and at 6-month and 12-month follow-up visits. Cutoff scores discriminating between the three cognitive categories were calculated for each instrument. For each cognitive group and instrument we addressed cognitive progression, sensitivity to change, and the minimally clinical important difference corresponding to conversion from one category to another.

RESULTS

The PD-CRS cutoff scores for MCI and dementia showed excellent sensitivity and specificity ratios that were not achieved with the other instruments. Throughout follow-up, in all cognitive groups, PD-CRS captured the rate of conversion from one cognitive category to another and also the different patterns in terms of cognitive trajectories.

CONCLUSION

The PD-CRS is a valid and reliable instrument to capture MCI and dementia syndromes in HD. It captures the different trajectories of cognitive progression as a function of cognitive status and shows sensitivity to change in MCI and dementia.

Recall and recognition subtests of the repeatable battery for the assessment of neuropsychological status and their relationship to biomarkers of Alzheimer's disease

Recently, two new recognition subtests for the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) were developed and initially validated in a cohort of older adults who were cognitively intact or classified as amnestic Mild Cognitive Impairment (MCI) or mild Alzheimer's disease (AD). The current paper extends that validation by comparing the recall and recognition subtests of the RBANS, including the existing and recently developed scores, to three commonly used biomarkers in AD in an expanded sample from the initial validation. One hundred fifty-four older adults (65 intact, 46 MCI, 43 AD) were administered the RBANS, which included the recently developed subtests for Story Recognition and Figure Recognition (hits, false positives, total correct), as part of a study on memory and biomarkers. Participants also completed magnetic resonance imaging to obtain hippocampal volumes, positron emission tomography to obtain amyloid plaque deposition, and a blood draw to obtain APOE ε4 status. Whereas correlations between recall scores and biomarkers tended to be moderate (average r = ±0.48), these correlations were comparable across the three recognition total scores (average r = ±0.42), but tended to be lower for recognition hits (average r = ±0.28) and false positives (average r = ±0.38). These results further validate the existing and recently developed recognition scores on the RBANS as providing useful information about brain and genetic pathology in older adults with intact and impaired cognitive functioning.

The Repeatable Battery for the Assessment of Neuropsychological Status, While Useful for Measuring Cognitive Changes in Manifest Huntington Disease, May Show Limited Utility in Premanifest Disease

BACKGROUND

The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) is a brief, standardized neuropsychological test that assesses several areas of cognitive function. Recent studies, although sparse, have examined the use of the RBANS to detect cognitive deficits in individuals with manifest Huntington disease (HD); however, no studies have investigated its utility to detect cognitive deficits in individuals with premanifest HD (PreHD), where cognitive symptoms are thought to be more subtle.

OBJECTIVE

To assess cognitive deficits in individuals with HD, particularly in individuals with PreHD, using an easily administered, brief but comprehensive, neuropsychological test.

METHOD

We administered the RBANS to 31 individuals with HD, 29 individuals with PreHD, and 22 healthy controls (HC) at an academic HD clinical research center and collected RBANS Total, Index, and subtest scores for group comparisons.

RESULTS

The HD group had significantly lower RBANS Total, Index, and subtest scores than the HC. The PreHD group had significantly lower RBANS Total scores and Coding subtest scores than the HC, but no other significant group differences were identified.

CONCLUSION

Our results substantiate previous findings of significant impairment on the RBANS in individuals with HD. In addition, we are the first to demonstrate that, although the RBANS can identify deficits in psychomotor speed and information processing in individuals with PreHD, it does not appear to have the ability to detect impairment in any additional cognitive domains in individuals with PreHD.

Functional connectivity abnormalities in Type I Chiari: associations with cognition and pain

There is initial evidence of microstructural abnormalities in the fibre-tract pathways of the cerebellum and cerebrum of individuals diagnosed with Type I Chiari malformation. However, it is unclear whether abnormal white matter architecture and macro-level morphological deviations that have been observed in Chiari translate to differences in functional connectivity. Furthermore, common symptoms of Chiari include pain and cognitive deficits, but the relationship between these symptoms and functional connectivity has not been explored in this population. Eighteen Type I Chiari patients and 18 age-, sex- and education-matched controls underwent resting-state functional MRI to measure functional connectivity. Participants also completed a neuropsychological battery and completed self-report measures of chronic pain. Group differences in functional connectivity were identified. Subsequently, pathways of significant difference were re-analyzed after controlling for the effects of attention performance and self-reported chronic pain. Chiari patients exhibited functional hypoconnectivity between areas of the cerebellum and cerebrum. Controlling for attention eliminated all deficits with the exception of that from the posterior cerebellar pathway. Similarly, controlling for pain also eliminated deficits except for those from the posterior cerebellar pathway and vermis VII. Patterns of Chiari hyperconnectivity were also found between regions of the cerebellum and cerebrum in Chiari patients. Hyperconnectivity in all regions was eliminated after controlling for attention except between left lobule VIII and the left postcentral gyrus and between vermis IX and the precuneus. Similarly, hyperconnectivity was eliminated after controlling for pain except between the default mode network and globus pallidus, left lobule VIII and the left postcentral gyrus, and Vermis IX and the precuneus. Evidence of both hyper- and hypoconnectivity were identified in Chiari, which is posited to support the hypothesis that the effect of increased pain in Chiari draws on neural resources, requiring an upregulation in inhibitory control mechanisms and resulting in cognitive dysfunction. Areas of hypoconnectivity in Chiari patients also suggest disruption in functional pathways, and potential mechanisms are discussed.

Factor Structure of the Repeatable Battery for the Assessment of Neuropsychological Status in Huntington's Disease

OBJECTIVE

The Repeatable Battery for the Assessment of Neuropsychological Status is a commonly used neuropsychological screening tool that is useful in a Huntington's disease (HD) population given its relatively brief administration time and assessment of multiple cognitive domains. Although 5 index scores are calculated, this structure has not been universally supported in clinical samples, which have often found a two- and three-factor structure to be better fitting. This study explored the Repeatable Battery for the Assessment of Neuropsychological Status factor structure in a large HD sample, which has not been done to date.

METHOD

In total, 147 individuals with HD completed the Repeatable Battery for the Assessment of Neuropsychological Status. An exploratory factor analysis was conducted to explore the Repeatable Battery for the Assessment of Neuropsychological Status factor structure.

RESULTS

Consistent with the findings from a majority of other clinical samples investigated, our results revealed a better fitting two-factor structure (verbal and visual).

CONCLUSION

The traditional Repeatable Battery for the Assessment of Neuropsychological Status index structure may not be valid in HD, which yields important clinical and research implications.

The Utility of the Repeatable Battery of Neuropsychological Status in Patients with Temporal and Non-temporal Lobe Epilepsy

OBJECTIVE

The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) is a brief neuropsychological battery that has been validated in the assessment of dementia and other clinical populations. The current study examines the utility of the RBANS in patients with epilepsy.

METHODS

Ninety-eight patients with epilepsy completed the RBANS as part of a more comprehensive neuropsychological evaluation. Performance on the RBANS was evaluated for patients with a diagnosis of temporal lobe epilepsy (TLE; n = 51) and other epilepsy patients (non-TLE, n = 47) in comparison to published norms. Multivariate analysis of variance compared group performances on RBANS indices. Rates of impairment were also compared across groups using cutoff scores of ≤1.0 and ≤1.5 standard deviations below the normative mean. Exploratory hierarchical regressions were used to examine the relations between epilepsy severity factors (i.e., age of onset, disease duration, and number of antiepileptic drugs [AEDs]) and RBANS performance.

RESULTS

TLE and non-TLE patients performed below the normative sample across all RBANS indices. Those with TLE performed worse than non-TLE patients on the Immediate and Delayed Memory indices and exhibited higher rates of general cognitive impairment. Number of AEDs was the only epilepsy severity factor that significantly predicted RBANS total performance, accounting for 14% of the variance.

CONCLUSIONS

These findings suggest that the RBANS has utility in evaluating cognition in patients with epilepsy and can differentiate TLE and non-TLE patients. Additionally, number of AEDs appears to be associated with global cognitive performance in adults with epilepsy.

Validation Study of a German Cognitive Battery for Huntington's Disease: Relationship Between Cognitive Performance, Functional Decline, and Disease Burden

Objective

Cognitive decline is a key characteristic of Huntington’s disease (HD). This study aimed to investigate the diagnostic accuracy of a cognitive battery with six tests used by most HD research centers to assess cognitive impairment in HD.

Method

In total, 106 HD patients in different disease stages with more (HD-CD, N = 30) and less cognitive impairments (HD-NC, N = 70) and 100 healthy controls (NC) were matched by age, sex, and education and were examined using a standardized protocol including cognitive, motor, and functional assessments.

Results

One-way between-groups analysis of variance showed that controls performed significantly better than HD patients and that HD-NC significantly outperformed HD-CD patients in all cognitive tests (NC > HD-NC > HD-CD), with all Games-Howell post-hoc tests p < .001. Analyses using area under the receiver-operating characteristic curve (AUC) disclosed the diagnostic accuracy of all tests included in the battery to discriminate between NC and HD patients with AUC ranging from 0.809 to 0.862 (all p < .001) and between HD-CD and HD-NC patients with AUC ranging from 0.833 to 0.899 (all p < .001). In both analysis, Stroop Color Naming Test showed the highest discriminative potential. Additional analyses showed that cognitive deficits in all domains progressed with disease duration. Moreover, cognitive performance correlated with the severity of motor and functional impairment (all p < .001) and with the Disease Burden Score regardless of disease duration and age.

Conclusion

Our results indicate that the cognitive battery is a suitable tool for assessing cognitive impairment in HD.

Reconsidering the RBANS Factor Structure: a Systematic Literature Review and Meta-Analytic Factor Analysis

The primary aim was to perform a systematic literature review and extract data necessary for a meta-analytic factor analysis of the RBANS. Secondary aims were to examine the potential validity and utility of the resulting factor structure. Literature was identified through a review of PsycINFO, PubMed, MEDLINE, Academic Search Complete, Psychology & Behavioral Sciences Collection, CINAHL Complete, Health Source: Nursing/Academic Edition, and SocINDEX. A two-stage meta-analytic structural equation modeling method was implemented to pool correlation matrices from primary studies and perform confirmatory factor analyses. Following model selection, factor scores were computed for two datasets and subjected to correlation and diagnostic accuracy analyses. A pooled correlation matrix was computed from 24 sample correlation matrices (N = 5299). Confirmatory factor analysis revealed that the theoretical five-factor model produced the best fit but only when error terms between Story Memory and Story Recall as well as between Figure Copy and Figure Recall were included. Regression-based factor scores showed mixed relationships with the manual-defined indices, and the overall diagnostic accuracy of the factor scores was adequate in both samples examined (AUC = 0.71 and 0.87). The five-factor model was an unexpected result given the failure of multiple previous studies to find support for that model. The five-factor model demonstrates several areas of potential improvement, including better representation of the factors by the indicators. The factor scores implied by this model also require further validation.

Understanding patient-reported outcome measures in Huntington disease: at what point is cognitive impairment related to poor measurement reliability?

PURPOSE

Symptom progression in Huntington disease (HD) is associated with cognitive decline which may interfere with the self-report of symptoms. Unfortunately, data to support or refute the psychometric reliability of patient-reported outcomes (PROs) as HD progresses are limited. This is problematic given that PROs are increasingly recognized as important measures of efficacy for new treatments.

METHODS

We examined PRO data from the HDQLIFE Measurement System (Speech Difficulties; Swallowing Difficulties; Chorea) in 509 individuals with premanifest, early-stage, or late-stage HD. Clinician-administered assessments of motor functioning (items from the UHDRS) and standardized objective assessments of cognition (Stroop, Symbol Digit Modalities) were also collected. We examined item bias using differential item functioning (DIF) across HD stage (premanifest, early-, late-) and relative to cognitive performance. We also examined the correlations between self-report and clinician ratings. Regression models that considered total cognitive ability were utilized to determine psychometric reliability of the PROs.

RESULTS

Most PRO items were free from DIF for both staging and cognition. There were modest correlations between PROs and clinician report (ranged from - 0.40 to - 0.60). Modeling analyses indicated that psychometric reliability breaks down with poorer cognition and more progressed disease stage; split-half reliability was compromised (i.e., split-half reliability < 0.80) when scores were < 136 for Chorea, < 109 for Speech Difficulties, and < 179 for Swallowing Difficulties.

CONCLUSIONS

Results indicate that the psychometric reliability of PROs can be compromised as HD symptoms progress and cognition declines. Clinicians should consider PROs in conjunction with other types of assessments when total cognition scores exceed critical thresholds.

Robotic technology provides objective and quantifiable metrics of neurocognitive functioning in survivors of critical illness:A feasibility study

PURPOSE

To assess the feasibility of using an integrated multimodal data collection strategy to characterize the post-intensive care syndrome (PICS).

MATERIALS AND METHODS

Adult patients admitted to the ICU requiring invasive mechanical ventilation for >24 h and/or requiring vasopressor support were eligible for enrollment. We assessed cognitive and sensorimotor function at 3- and 12-months after ICU discharge with the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and with the KINARM robot.

RESULTS

At 3- and 12-months after ICU discharge, 28/70 (40%) and 22/70 (31%) returned for follow-up testing, respectively. Prominent reasons for declining testing at 3- and 12-months included: not interested (40% and 38%) and health complications (31% and 31%). The majority of returning participants completed all tasks (96%-100%) and 100% of available data was recorded. On the RBANS, 54% (3 months) and 32% (12 months) of individuals were impaired in visuospatial/constructional skills. Similarly, the KINARM assessments demonstrated that 56% of individuals had visuospatial/executive dysfunction at 3 months, and 40% had impairment at 12 months. Individual scores indicated substantial variability.

CONCLUSIONS

We demonstrated that it was feasible to quantify neurological dysfunction among participants that returned for follow-up testing. However, future investigations will need to implement multiple retention strategies.

TRIAL REGISTRATION

This trial is registered on clinicaltrials.gov (Identifier: NCT02344043), retrospectively registered January 8, 2015.

Assessing Decline: Visualising Progression in Huntington's Disease using a Clinical Dashboard with Enroll-HD Data

BACKGROUND

In Huntington's disease (HD), it remains unclear how symptom severity and rate of symptomatic change relates to age and CAG repeat number (CAGn). It is often difficult for clinicians to assess whether an affected individual's symptoms are progressing at a similar rate to their affected peers, limiting their ability to intervene at the most appropriate time.

OBJECTIVE

To develop a clinical dashboard that compares an individual's total motor score (TMS), total functional capacity (TFC) and symbol digit modality test (SDMT) scores against a global cohort, controlling for age and CAGn. The dashboard could then be used by clinicians to identify individuals progressing at a disproportionate rate to his or her peers.

METHODS

Annualised longitudinal clinical assessment scores from the Enroll-HD dataset were used to generate decline trajectories of the global cohort, allowing cross-sectional (TMS n = 734; TFC n = 734; SDMT n = 694) and longitudinal (TMS n = 270; TFC n = 270; SDMT n = 247) comparison with individual clinical symptom rating scores, to assess decline relative to affected peers.

RESULTS

An electronic dashboard with a dynamic output display was created that rapidly compares clinical symptom rating scores of a specific individual against affected peers from a global cohort of comparable CAGn.

CONCLUSIONS

This study shows the potential for use of multi-centre trial data in allowing comparison of the individual to a larger group to facilitate improved decision-making for individual patients. Visualisation of these metrics via a clinical dashboard demonstrates how it may aid identification of those with disproportionate decline, offering potential for intervention at specific critical points in the disease course.

Rating scales for behavioral symptoms in Huntington's disease: Critique and recommendations

Behavioral symptoms are an important feature of Huntington's disease and contribute to impairment in quality of life. The Movement Disorder Society commissioned the assessment of the clinimetric properties of rating scales in Huntington's disease to make recommendations regarding their use, following previously used standardized criteria. A systematic literature search was conducted to identify the scales used to assess behavioral symptoms in Huntington's disease. For the purpose of this review, 7 behavioral domains were deemed significant in Huntington's disease: irritability, anxiety, depression, apathy, obsessive-compulsive behaviors, psychosis, and suicidal ideation. We included a total of 27 behavioral rating scales, 19 of which were of a single behavioral domain and the remaining 8 scales included multiple behavioral domains. Three rating scales were classified as "recommended" exclusively for screening purposes: the Irritability Scale for irritability, the Beck Depression Inventory-II, and the Hospital Anxiety and Depression Scale for depression. There were no "recommended" scales for other purposes such as diagnosis, severity, or change in time or to treatment. The main challenges identified for assessment of behavioral symptoms in Huntington's disease are the co-occurrence of multiple behavioral symptoms, the particular features of a behavioral symptom in Huntington's disease, and the need to address stage- and disease-specific features, including cognitive impairment and lack of insight. The committee concluded that there is a need to further validate currently available behavioral rating scales in Huntington's disease to address gaps in scale validation for specific behavioral domains and purpose of use. © 2016 International Parkinson and Movement Disorder Society.

Rating scales for cognition in Huntington's disease: Critique and recommendations

Cognitive impairment is one of the main features of Huntington's disease and is present across the disease spectrum. As part of the International Parkinson's Disease and Movement Disorder Society-sponsored project to review all clinical rating scales used in Huntington's disease, a systematic review of the literature was performed to identify cognitive scales used in Huntington's disease and make recommendations for their use. A total of 17 cognitive scales were identified and evaluated. None of the scales met criteria for a "recommended" status. For assessing severity of cognitive dysfunction, the Montreal Cognitive Assessment was "recommended with caveats." The UHDRS Cognitive Assessment, the UHDRS-For Advanced Patients cognitive section, the Alzheimer's Disease Assessment Scale-Cognitive Subscale, the Frontal Assessment Battery, the Mattis Dementia Rating Scale, the Mini-Mental State Examination, and the Repeatable Battery for the Assessment of Neuropsychological Status were "suggested" for evaluating severity of cognitive impairment. The MoCA was "suggested" as a screening tool for cognitive impairment. The major challenge in the assessment of cognition in Huntington's disease is the lack of a formal definition of dementia and/or mild cognitive impairment in this disease. The committee concluded that there is a need to further validate currently available cognitive scales in Huntington's disease, but that it is premature to recommend the development of new scales. Recently developed Huntington's disease-specific scales, such as the Huntington's Disease-Cognitive Assessment Battery, hold promise but require the completion of more comprehensive clinimetric development. © 2017 International Parkinson and Movement Disorder Society.

Progress in developing transgenic monkey model for Huntington's disease

Huntington's disease (HD) is a complex neurodegenerative disorder that has no cure. Although treatments can often be given to relieve symptoms, the neuropathology associated with HD cannot be stopped or reversed. HD is characterized by degeneration of the striatum and associated pathways that leads to impairment in motor and cognitive functions as well as psychiatric disturbances. Although cell and rodent models for HD exist, longitudinal study in a transgenic HD nonhuman primate (i.e., rhesus macaque; HD monkeys) shows high similarity in its progression with human patients. Progressive brain atrophy and changes in white matter integrity examined by magnetic resonance imaging are coherent with the decline in cognitive behaviors related to corticostriatal functions and neuropathology. HD monkeys also express higher anxiety and irritability/aggression similar to human HD patients that other model systems have not yet replicated. While a comparative model approach is critical for advancing our understanding of HD pathogenesis, HD monkeys could provide a unique platform for preclinical studies and long-term assessment of translatable outcome measures. This review summarizes the progress in the development of the transgenic HD monkey model and the opportunities for advancing HD preclinical research.

Cognitive and behavioral changes in Huntington disease before diagnosis

Phenotypic manifestations of Huntington disease (HD) can be detected at least 15 years prior to the time when a motor diagnosis is given. Advances in clinical care and future research will require consistent use of HD definitions and HD premanifest (prodromal) stages being used across clinics, sites, and countries. Cognitive and behavioral (psychiatric) changes in HD are summarized and implications for ongoing advancement in our knowledge of prodromal HD are suggested. The earliest detected cognitive changes are observed in the Symbol Digit Modalities Test, Stroop Interference, Stroop Color and Word Test-interference condition, and Trail Making Test. Cognitive changes in the middle and near motor diagnostic stages of prodromal HD involve nearly every cognitive test administered and the greatest changes over time (i.e., slopes) are found in those prodromal HD participants who are nearest to motor diagnosis. Psychiatric changes demonstrate significant worsening over time and remain elevated compared with healthy controls throughout the prodromal disease course. Psychiatric and behavior changes in prodromal HD are much lower than that obtained using cognitive assessment, although the psychiatric and behavioral changes represent symptoms most debilitating to independent capacity and wellness.

Effort in acute traumatic brain injury: considering more than pass/fail

PURPOSE/OBJECTIVE

Performance validity is often conceptualized as a dichotomous process. Effort likely lies on a continuum, however, and psychologists' tendency to rely on pass/fail descriptors of one's effort may not be the only approach. The current study aims to show that when performance validity is considered on a continuum, it may provide clinical information related to cognitive functioning.

RESEARCH METHOD/DESIGN

Forty-four patients with moderate or severe traumatic brain injury were evaluated with the Repeatable Battery for the Assessment of Neuropsychological Status upon their emergence from posttraumatic amnesia. From this data, previously developed effort index scores and "other cognitive functions" index scores were calculated.

RESULTS

Performance on the effort index significantly accounted for the patients' performance on a cognitive composite score after considering education and severity of injury.

CONCLUSIONS/IMPLICATIONS

Findings suggest that more in-depth analysis of validity test performance is beneficial to gauge a patient's level of effort and is important to consider when interpreting results and in treatment planning.

Evaluating Neurocognitive Deficits in Patients With Multiple Sclerosis Via a Brief Neuropsychological Approach

Recent research demonstrates neurocognitive deficits are present early in the sequelae of multiple sclerosis (MS). This is an important consideration given the functional activities of daily living, such as employment, that can be impacted by neurocognitive dysfunction. This study investigated the utility of a brief neuropsychological battery, the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), to evaluate neurocognitive deficits in patients with MS and to examine the relationship between a measure of functional disability (Expanded Disability Status Scale [EDSS]) and the RBANS. Participants were 49 patients with MS (Mage = 45.39 years) who completed the RBANS as part of a neuropsychological assessment and 49 demographically matched healthy controls (Mage = 45.39 years). Multivariate analysis of variance revealed that the two groups differed on the RBANS. Descriptive discriminant analysis indicated the groups differed on domains of attention, language, immediate memory, and delayed memory. EDSS scores were a good predictor of neurocognitive dysfunction in patients with advanced disability but not for patients with mild disability. The RBANS seems to be effective in identifying cognitive dysfunction in patients with MS, and caution should be used in extrapolating cognitive deficits for patients with low EDSS scores.

Norms and reliability for the Spanish version of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Form A

Alzheimer's disease (AD) is the most common cause of dementia in the adult population. Tools capable of detecting predementia and established diagnoses of dementia are very important for assessing these patients. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) is a brief neuropsychological battery that has been successful at detecting cognitive impairment in degenerative and nondegenerative neurological diseases. The objective of this study was to test reliability and sensibility and obtain normative data of a Spanish adaptation of the RBANS. In this study, 50 participants with AD and 336 healthy participants stratified according to the Spanish Census, with different levels of education, were tested with the RBANS (Form A). Descriptive analyses were performed on a pilot sample from the general population, and comparative analyses were performed on data from the two samples. We obtained an overall reliability coefficient (Cronbach's alpha) of .92. RBANS showed strong specificity and moderately low sensitivity. Participants in the AD group performed significantly worse on most subtests than control participants. Implications with regard to the specificity and sensitivity of the Spanish version of the RBANS are discussed.

Visual system integrity and cognition in early Huntington's disease

Posterior cortical volume changes and abnormal visuomotor performance are present in patients with Huntington's disease (HD). However, it is unclear whether posterior cortical volume loss contributes to abnormal neural activity, and whether activity changes predict cognitive dysfunction. Using magnetic resonance imaging (MRI), we investigated brain structure and visual network activity at rest in patients with early HD (n = 20) and healthy controls (n = 20). The symbol digit modalities test (SDMT) and subtests of the Visual Object and Space Perception Battery were completed offline. For functional MRI data, a group independent component analysis was used. Voxel-based morphometry was employed to assess regional brain atrophy, and 'biological parametric mapping' analyses were included to investigate the impact of atrophy on neural activity. Patients showed significantly worse visuomotor and visual object performance than controls. Structural analyses confirmed occipitotemporal atrophy. In patients and controls, two spatiotemporally distinct visual systems were identified. Patients showed decreased activity in the left fusiform cortex, and increased left cerebellar activity. These findings remained stable after correction for brain atrophy. Lower fusiform cortex activity was associated with lower SDMT performance and with higher disease burden scores. These associations were absent when cerebellar function was related to task performance and disease burden. The results of this study suggest that regionally specific functional abnormalities of the visual system can account for the worse visuomotor cognition in HD patients. However, occipital volume changes cannot sufficiently explain abnormal neural function in these patients.

Biomarker development for Huntington's disease

Huntington's disease (HD) is a fatal inherited neurodegenerative disorder, treatment to slow the progression of which has not yet been found. Human clinical trials to test a number of therapeutic strategies are underway or imminent, facilitated in part by the recent development of biomarkers that might be used as surrogate endpoints in such trials. However, although much progress in developing HD biomarkers has been made, ongoing work seeks to improve the sensitivity and reliability of current measures, and to demonstrate that they correspond to clear meaningful benefit to patients. Of particular importance is the identification of state biomarkers that can be used in pre-manifest HD gene carriers to test therapies hoped to delay symptom onset in these individuals. Functional, neuroimaging and biochemical biomarkers continue to be investigated for use in the development of disease-modifying treatments of HD.

Longitudinal pilot-study of Sustained Attention to Response Task and P300 in manifest and pre-manifest Huntington's disease

BACKGROUND

Earlier research has found cross-sectional attentional control deficits in manifest Huntington's disease (HD) using neuropsychological testing combined with simultaneous P300 registration. In the current pilot-study, we investigate attentional control in pre-manifest and manifest HD over a 3-year follow-up period.

METHOD

Five manifest HD (MHD), 9 pre-manifest HD (PMHD), and 12 control subjects were included. Sustained Attention to Response task (SART) and P300 registration resulted in number of errors, reaction time (RT), and P300 amplitude and latency. RT change patterns surrounding No-go trials were also investigated. Within-subject differences were tested using paired-samples t-tests and between-group results with ANCOVA on delta scores (follow-up--baseline scores).

RESULTS

Manifest HD made more errors and were slower than controls and PMHD. Longitudinally, MHD showed an overall RT increase and a specific slowing on trials preceding a correct No-go trial (within-group effects). The latter was also seen in PMHD. P300 latency prolongation was found for controls on No-go and for MHD on Go trials. On specific trials surrounding both correct and incorrect No-go trials, MHD became significantly slower over time than controls and PMHD (between-group effects).

CONCLUSIONS

Over 3-years, MHD subjects became slower on the SART and showed a prolongation of P300 latency on specific SART trials. Specific slowing of performance over time was also seen in PMHD, suggestive of compensatory mechanisms in this group.

Cognitive reserve and brain reserve in prodromal Huntington's disease

Huntington disease (HD) is associated with decline in cognition and progressive morphological changes in brain structures. Cognitive reserve may represent a mechanism by which disease-related decline may be delayed or slowed. The current study examined the relationship between cognitive reserve and longitudinal change in cognitive functioning and brain volumes among prodromal (gene expansion-positive) HD individuals. Participants were genetically confirmed individuals with prodromal HD enrolled in the PREDICT-HD study. Cognitive reserve was computed as the composite of performance on a lexical task estimating premorbid intellectual level, occupational status, and years of education. Linear mixed effects regression (LMER) was used to examine longitudinal changes on four cognitive measures and three brain volumes over approximately 6 years. Higher cognitive reserve was significantly associated with a slower rate of change on one cognitive measure (Trail Making Test, Part B) and slower rate of volume loss in two brain structures (caudate, putamen) for those estimated to be closest to motor disease onset. This relationship was not observed among those estimated to be further from motor disease onset. Our findings demonstrate a relationship between cognitive reserve and both a measure of executive functioning and integrity of certain brain structures in prodromal HD individuals.

Sensitivity of the RBANS to acute traumatic brain injury and length of post-traumatic amnesia

OBJECTIVE

Although the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) has been shown to be a useful tool in evaluating the cognitive status of patients with dementia, stroke, schizophrenia and post-acute traumatic brain injury (TBI), no studies have examined its utility in an acute TBI setting. The current study investigates the RBANS' sensitivity to acute TBI, hypothesizing that the presence and severity of injury is predictive of worse RBANS performance.

METHOD

Neuropsychological testing was conducted an average of 6.1 days after emergence from post-traumatic amnesia (PTA). RBANS results were evaluated based on a normative basis, pre-injury estimates, and brain injury severity.

RESULTS

In this sample of acute TBI patients (n = 51), the mean index scores on the RBANS ranged from 1.59-2.36 SD below the mean of the standardization sample. Each WRAT-4 Reading sub-test score was above the corresponding RBANS Total Scale Index score (t(31) = 10.32, p < 0.001). Regression analyses revealed that Delayed Memory (β = - 0.365, p < 0.007) and Total Score (β = -0.297, p < 0.023) indices were significantly predicted by PTA length after controlling for age and education.

CONCLUSIONS

The RBANS appears to be a useful tool in assessing the presence and severity of acute TBI.

Symptom validity test performance in the Huntington Disease Clinic

Symptom validity tests (SVTs) are often used in neuropsychological assessment; however, recent studies indicate that cognitive impairment/dementia may contribute to failing scores on some effort tests. The purpose of this study was to characterize how individuals with Huntington disease (HD) perform on three SVTs and to examine the relationship between SVT performance and demographic and clinical variables. Results indicate that while the majority of HD patients passed the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) Effort Index (EI; 82% of n = 121) and the Test of Memory Malingering (92% of n = 36), failure of these SVTs was associated with poorer cognitive and adaptive functioning, and greater motor impairment. Results showed that less than one-third passed the RBANS Effort Scale (ES; 30% of n = 43) and few clinical and demographic variables were correlated with this SVT performance. Although some SVTs may be better suited to HD, cognitive ability should be considered when evaluating effort in HD.

Evaluation of longitudinal 12 and 24 month cognitive outcomes in premanifest and early Huntington's disease

BACKGROUND

Deterioration of cognitive functioning is a debilitating symptom in many neurodegenerative diseases, such as Huntington's disease (HD). To date, there are no effective treatments for the cognitive problems associated with HD. Cognitive assessment outcomes will have a central role in the efforts to develop treatments to delay onset or slow the progression of the disease. The TRACK-HD study was designed to build a rational basis for the selection of cognitive outcomes for HD clinical trials.

METHODS

There were a total of 349 participants, including controls (n=116), premanifest HD (n=117) and early HD (n=116). A standardised cognitive assessment battery (including nine cognitive tests comprising 12 outcome measures) was administered at baseline, and at 12 and 24 months, and consisted of a combination of paper and pencil and computerised tasks selected to be sensitive to cortical-striatal damage or HD. Each cognitive outcome was analysed separately using a generalised least squares regression model. Results are expressed as effect sizes to permit comparisons between tasks.

RESULTS

10 of the 12 cognitive outcomes showed evidence of deterioration in the early HD group, relative to controls, over 24 months, with greatest sensitivity in Symbol Digit, Circle Tracing direct and indirect, and Stroop word reading. In contrast, there was very little evidence of deterioration in the premanifest HD group relative to controls.

CONCLUSIONS

The findings describe tests that are sensitive to longitudinal cognitive change in HD and elucidate important considerations for selecting cognitive outcomes for clinical trials of compounds aimed at ameliorating cognitive decline in HD.

Biomarkers for Huntington's disease: an update

Huntington's disease (HD) is a devastating autosomal-dominant neurodegenerative condition caused by a CAG repeat expansion in the gene encoding huntingtin which is characterised by progressive motor impairment, cognitive decline and neuropsychiatric disturbances. There are currently no disease-modifying treatments available to patients, but a number of therapeutic strategies are currently being investigated, chief among them are nucleotide-based 'gene silencing' approaches, modulation of huntingtin post-translation modification and enhancing clearance of the mutant protein. In 2008, the authors' review highlighted the need to develop and validate biomarkers and provided a systematic head-to-head comparison of such measures. They searched the PubMed database for publications, which covered each of the subheadings mentioned below. They identified from these list studies which had relevance to biomarker development, as defined in their previous review. Building on a tradition of collaborative research in HD, great advances have been made in the field since that time and a range of outcome measures are now being recommended in order to assess efficacy in future therapeutic trials.

Potential endpoints for clinical trials in premanifest and early Huntington's disease in the TRACK-HD study: analysis of 24 month observational data

BACKGROUND

TRACK-HD is a prospective observational biomarker study in premanifest and early Huntington's disease (HD). In this report we define a battery of potential outcome measures for therapeutic trials.

METHODS

We assessed longitudinal data collected at baseline, 12 months, and 24 months at sites in Leiden (Netherlands), London (UK), Paris (France), and Vancouver (Canada). Participants were individuals without HD but carrying the mutant HTT gene (ie, premanifest HD), patients with early HD, and healthy control individuals matched by age and sex to the combined HD groups. Data were collected with 3T MRI, clinical, cognitive, quantitative motor, oculomotor, and neuropsychiatric assessments. We estimated adjusted, between-group differences in rates of change in these measures and concomitant longitudinal effect sizes.

FINDINGS

Longitudinal data were available for 116 control individuals, 117 premanifest gene carriers, and 116 participants with early HD. Significantly greater progressive grey-matter, white-matter, whole-brain, and regional atrophy was recorded in the premanifest and early HD groups than in the control group. Effect sizes for atrophy rates between participants with early HD and controls were largest in the caudate (2·04, 95% CI 1·68 to 2·48) and white matter (1·70, 1·40 to 2·08). Functional, quantitative motor, and cognitive measures deteriorated to a greater extent in the early HD group than in controls, with the largest effect size in the symbol digit modality test (1·00, 0·67 to 1·27). In the early HD group, changes in structural imaging and various cognitive and quantitative motor scores were associated with worsening total motor score (TMS) and total functional capacity (TFC). In the premanifest group, despite significant declines in regional and overall brain volumes, few functional variables showed significant 24 month change compared with controls; TMS, emotion recognition, and speeded tapping were exceptions. Premanifest individuals with progression, predefined as an increase in TMS score of 5 points or more, any TFC decline, or a new diagnostic confidence score of 4, exhibited higher rates of brain atrophy and deterioration on some quantitative motor tasks compared with other premanifest participants.

INTERPRETATION

On the basis of longitudinal effect size, we recommend several objective outcome measures for clinical trials in participants with early HD. Hypothetical treatment effects defined by slower longitudinal changes in these measures would be detectable over a realistic timescale with practical sample sizes. The restricted 24 month cognitive or motor decline in the premanifest sample illustrates the greater challenge in trial design for this group.

FUNDING

CHDI/HighQ Foundation Inc.

No evidence of impaired gastric emptying in early Huntington's Disease

Background: Several factors, such as dysphagia, an increased motor activity, increased metabolic rate and a hypermetabolic state have been discussed as contributing to weight loss even at the early stages of Huntington’s Disease (HD). Aim of this pilot study was to investigate gastric emptying as a possible reason for weight loss in HD.

Methods: 11 HD participants at early stages of the disease and matched controls were investigated by using the well-established and non-invasive 13C-octanoate breath test. The “Gastroparesis Cardinal Symptom Index” and the “Short-Form Leeds Dyspepsia Questionnaire” were used for clinical evaluation of gastroparesis or dyspepsia.

Results: When compared to standard values ​​given in literature and controls all HD patients had normal breath test results. There was no evidence of gastroparesis or dyspepsia. There was a correlation of breath test results with the cognitive and functional performance of HD participants.

Conclusion: According to our data, there is no evidence of impaired gastric emptying in early HD. We can not exclude that gastric emptying contributes to weight loss at more advanced stages of the disease.

Reliability and validity of the Repeatable Battery for the Assessment of Neuropsychological Status in community-dwelling elderly

INTRODUCTION

The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) is a widely used screening instrument in neuropsychological assessment and is a brief, individually administered measure. The present study aims to assess the reliability and validity of the Chinese version of the RBANS in community-dwelling elderly.

MATERIAL AND METHODS

All subjects come from the community-dwelling elderly in Shanghai, China. They completed a questionnaire concerning demographic information, the mini-mental state examination (MMSE) and the Chinese version of the RBANS. To test for internal consistency, Cronbach's α was calculated for all six RBANS indices. Correlations between each of the RBANS and MMSE subtests were conducted to measure the concurrent validity. A confirmatory factor analysis (CFA) was conducted to test the construct validity.

RESULTS

The final sample of participants included 236 community-dwelling elderly. The mean total score on the RBANS was 86.02 (±14.19). The RBANS total score showed strong internal consistency (r = 0.806), and the coefficient α value for each of the RBANS scales ranged from 0.142 to 0.727. The total RBANS score was highly correlated with that of the MMSE (r = 0.594, p<0.001), and the RBANS subtests also demonstrated strong correlations with most of the MMSE subtests. The results of the CFA indicated an acceptable fit between the Chinese version of the RBANS and the original.

CONCLUSIONS

The Chinese version of the RBANS had relatively good reliability and validity in a community-dwelling elderly sample. It may be a useful screening instrument for conducting cognitive assessments in community-dwelling elderly.

Modeling longitudinal change in motor and cognitive processing speed in presymptomatic Huntington's disease

Persons who have the genetic mutation responsible for Huntington's disease (HD) have been shown to exhibit lower cognitive test scores years prior to manifest HD. Most studies have examined cognitive performance in presymptomatic persons by using estimated times to manifest HD based on published algorithms. We followed 19 gene-positive persons who were presymptomatic using an objective criterion (i.e., Quantified Neurological Exam score ≤ 10) at baseline for up to 21 years (median = 5 years) with periannual neuropsychological assessments until a diagnosis of manifest HD. Results showed that our tests of information- and psychomotor-processing speed that place minimal demands on cognition, worsening performance became evident 5-10 years prior to the development of manifest HD. In conclusion, cognitive decline precedes motor signs in HD and may be an important target in clinical trials and early intervention. Cognitive test scores may also improve the ability to predict disease onset among gene mutation carriers and help families to better plan for potential personal and economic hardship.

Deficits in stepping response time are associated with impairments in balance and mobility in people with Huntington disease

Huntington disease (HD) is a disorder characterized by chorea, dystonia, bradykinesia, cognitive decline and psychiatric comorbidities. Balance and gait impairments, as well as falls, are common manifestations of the disease. The importance of compensatory rapid stepping to maintain equilibrium in older adults is established, yet little is known of the role of stepping response times (SRTs) in balance control in people with HD. SRTs and commonly-used clinical measures of balance and mobility were evaluated in fourteen symptomatic participants with HD, and nine controls at a university mobility research laboratory. Relative and absolute reliability, as well as minimal detectable change in SRT were quantified in the HD participants. HD participants exhibited slower SRTs and poorer dynamic balance, mobility and motor performance than controls. HD participants also reported lower balance confidence than controls. Deficits in SRT were associated with low balance confidence and impairments on clinical measures of balance, mobility, and motor performance in HD participants. Measures of relative and absolute reliability indicate that SRT is reliable and reproducible across trials in people with HD. A moderately low percent minimal detectable change suggests that SRT appears sensitive to detecting real change in people with HD. SRT is impaired in people with HD and may be a valid and objective marker of disease progression.

The RBANS Effort Index: base rates in geriatric samples

The Effort Index (EI) of the RBANS was developed to assist clinicians in discriminating patients who demonstrate good effort from those with poor effort. However, there are concerns that older adults might be unfairly penalized by this index, which uses uncorrected raw scores. Using five independent samples of geriatric patients with a broad range of cognitive functioning (e.g., cognitively intact, nursing home residents, probable Alzheimer's disease), base rates of failure on the EI were calculated. In cognitively intact and mildly impaired samples, few older individuals were classified as demonstrating poor effort (e.g., 3% in cognitively intact). However, in the more severely impaired geriatric patients, over one third had EI scores that fell above suggested cutoff scores (e.g., 37% in nursing home residents, 33% in probable Alzheimer's disease). In the cognitively intact sample, older and less educated patients were more likely to have scores suggestive of poor effort. Education effects were observed in three of the four clinical samples. Overall cognitive functioning was significantly correlated with EI scores, with poorer cognition being associated with greater suspicion of low effort. The current results suggest that age, education, and level of cognitive functioning should be taken into consideration when interpreting EI results and that significant caution is warranted when examining EI scores in elders suspected of having dementia.