Comparison of cognitive and UHDRS measures in monitoring disease progression in Huntington's disease: a 12-month longitudinal study

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.

Montreal Cognitive Assessment (MoCA) performance in Huntington's disease patients correlates with cortical and caudate atrophy

Huntington's Disease (HD) is an autosomal neurodegenerative disease characterized by motor, cognitive, and psychiatric symptoms. Cognitive impairment develops gradually in HD patients, progressing later into a severe cognitive dysfunction. The Montreal Cognitive Assessment (MoCA) is a brief screening test commonly employed to detect mild cognitive impairment, which has also been useful to assess cognitive decline in HD patients. However, the relationship between MoCA performance and brain structural integrity in HD patients remains unclear. Therefore, to explore this relationship we analyzed if cortical thinning and subcortical nuclei volume differences correlated with HD patients' MoCA performance. Twenty-two HD patients and twenty-two healthy subjects participated in this study. T1-weighted images were acquired to analyze cortical thickness and subcortical nuclei volumes. Group comparison analysis showed a significantly lower score in the MoCA global performance of HD patients. Also, the MoCA total score correlated with cortical thinning of fronto-parietal and temporo-occipital cortices, as well as with bilateral caudate volume differences in HD patients. These results provide new insights into the effectiveness of using the MoCA test to detect cognitive impairment and the brain atrophy pattern associated with the cognitive status of prodromal/early HD patients.

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.

Gray Matter Vulnerabilities Predict Longitudinal Development of Apathy in Huntington's Disease

BACKGROUND

Apathy, a common neuropsychiatric disturbance in Huntington's disease (HD), is subserved by a complex neurobiological network. However, no study has yet employed a whole-brain approach to examine underlying regional vulnerabilities that may precipitate apathy changes over time.

OBJECTIVES

To identify whole-brain gray matter volume (GMV) vulnerabilities that may predict longitudinal apathy development in HD.

METHODS

Forty-five HD individuals (31 female) were scanned and evaluated for apathy and other neuropsychiatric features using the short-Problem Behavior Assessment for a maximum total of six longitudinal visits (including baseline). In order to identify regions where changes in GMV may describe changes in apathy, we performed longitudinal voxel-based morphometry (VBM) on those 33 participants with a magnetic resonance imaging (MRI) scan on their second visit at 18 ± 6 months follow-up (78 MRI datasets). We next employed a generalized linear mixed-effects model (N = 45) to elucidate whether initial and specific GMV may predict apathy development over time.

RESULTS

Utilizing longitudinal VBM, we revealed a relationship between increases in apathy and specific GMV atrophy in the right middle cingulate cortex (MCC). Furthermore, vulnerability in the right MCC volume at baseline successfully predicted the severity and progression of apathy over time.

CONCLUSIONS

This study highlights that individual differences in apathy in HD may be explained by variability in atrophy and initial vulnerabilities in the right MCC, a region implicated in action-initiation. These findings thus serve to facilitate the prediction of an apathetic profile, permitting targeted, time-sensitive interventions in neurodegenerative disease with potential implications in otherwise healthy populations. © 2021 International Parkinson and Movement Disorder Society.

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.

Longitudinal assessment of the Unified Huntington's Disease Rating Scale (UHDRS) and UHDRS-For Advanced Patients (UHDRS-FAP) in patients with late stage Huntington's disease

BACKGROUND AND PURPOSE

Symptoms and signs in patients with Huntington's disease are usually assessed with the Unified Huntington's Disease Rating Scale (UHDRS). Ceiling and floor effects hamper the measurement of disease progression in patients with late stage Huntington's disease and therefore the UHDRS-For Advanced Patients (UHDRS-FAP) has been developed. The aim of this longitudinal study was to examine if the UHDRS-FAP and UHDRS are sensitive enough to detect change over time in late stage Huntington's disease.

METHODS

Forty nursing home residents and patients receiving day-care were assessed with the UHDRS, UHDRS-FAP and Care Dependency Scale (CDS). After 6 months, the assessment scales were completed again in 29 patients. Changes between baseline and follow-up were calculated using paired t tests. Wilcoxon signed-rank tests were used to calculate longitudinal changes for middle and late stage patients separately.

RESULTS

The motor and cognitive score of the UHDRS-FAP deteriorated during 6 months' follow-up, whilst the motor and cognitive score of the UHDRS did not show change. Two functional domains of the UHDRS and the CDS also declined. The behavioral score significantly improved with both rating scales in late stage patients.

CONCLUSIONS

Our results suggest that the UHDRS-FAP motor and cognitive score, the functional domains of the UHDRS, and the CDS can detect disease progression in late stage Huntington's disease. Therefore, the use of these scores in nursing homes is recommended to optimize care by monitoring disease progression and by evaluating the effect of interventions in clinical care. Psychiatric symptoms seem to fade away as the disease progresses.

Assessment Scales for Patients with Advanced Huntington's Disease: Comparison of the UHDRS and UHDRS-FAP

Background

The standard clinical assessment tool in Huntington's disease is the Unified Huntington's Disease Rating Scale (UHDRS). In patients with advanced Huntington's disease ceiling and floor effects of the UHDRS hamper the detection of changes. Therefore, the UHDRS-For Advanced Patients (UHDRS-FAP) has been designed for patients with late-stage Huntington's disease.

Objectives

This cross-sectional study aims to examine if the UHDRS-FAP can differentiate better between patients with advanced Huntington's disease than the UHDRS.

Methods

Forty patients, who were institutionalized or received day-care, were assessed with the UHDRS, UHDRS-FAP, and Care Dependency Scale (CDS). The severity of Huntington's disease was defined by the Total Functional Capacity (TFC). Comparisons between consecutive TFC stages were performed for all domains of the UHDRS, UHDRS-FAP, and CDS using Mann-Whitney U tests.

Results

The motor scores of the UHDRS-FAP and UHDRS were the only subscales with significantly worse scores in TFC stage 5 compared to stage 4. In TFC stages 4-5, the range of the UHDRS-FAP motor score was broader, the standard error of measurement was lower, and the effect size r was higher than for the UHDRS motor score. The CDS declined significantly across all TFC stages.

Conclusions

Our results suggest that the UHDRS-FAP motor score might differentiate better between patients with severe Huntington's disease than the UHDRS motor score. Therefore, the UHDRS-FAP motor score is potentially a better instrument than the UHDRS motor score to improve disease monitoring and, subsequently, care in patients with advanced Huntington's disease in long-term care facilities.

Interrater Reliability of the Unified Huntington's Disease Rating Scale-Total Motor Score Certification

BACKGROUND

The clinical assessment of motor symptoms in Huntington's disease is usually performed with the Unified Huntington's Disease Rating Scale-Total Motor Score (UHDRS-TMS). A high interrater reliability is desirable to monitor symptom progression. Therefore, a teaching video and a system for annual online certification has been developed and implemented.

OBJECTIVES

The aim of this study is to investigate the interrater reliability of the UHDRS-TMS and of its subitems, and to examine the performance of raters in consecutive years.

METHODS

Data from the online UHDRS-TMS certification were used. The interrater reliability was assessed for all first-time participants (n = 944) between 2009 and 2016. Intraclass correlation coefficients (ICC) were calculated for each year separately and the mean was taken as the total ICC.

RESULTS

The UHDRS-TMS (ICC = 0.847), tandem walking (0.824), pronate/supinate hands left (0.713), and retropulsion pull test (0.706) showed good interrater reliability. Poor interrater reliability was found for maximal dystonia of the left and right upper extremity (0.187 and 0.322, respectively), maximal dystonia of the left and right lower extremity (0.200 and 0.256, respectively), and maximal dystonia of the trunk (0.389), tongue protrusion (0.266), and rigidity arms left (0.390). Raters performed significantly worse on follow-up certification compared to their first certification.

CONCLUSIONS

Our results suggest that the rating of dystonia (absent, slight, mild, moderate, or marked) is subjective and difficult to interpret, especially on video. Therefore, changing the dystonia items of the UHDRS-TMS should be explored. We also recommend that raters should watch the UHDRS-TMS teaching video before each certification.

Longitudinal Change in Performance on the Montreal Cognitive Assessment in Older Adults

OBJECTIVE

The Montreal Cognitive Assessment (MoCA) is a brief screening measure commonly used to determine cognitive status among older adults. Despite the popularity of the MoCA, there has been little research into how performance on the MoCA changes over time in healthy older adults.

METHODS

The present study examined a sample of older adults (n = 53) recruited for a longitudinal study of healthy aging. Change in total MoCA score at three time points (baseline, 12 months, and 48 months) and scores from the Repeatable Battery for the Assessment of Neuropsychological Status at five time points (RBANS; baseline 12 months, 24 months, 36 months, and 48 months) were assessed using repeated measures analyses.

RESULTS

Total MoCA score significantly increased across time, particularly between the first and second administrations. Scores did not significantly differ between the second (12 month) and third (48 month) administrations. When grouped by baseline performance, individuals who scored low at baseline significantly improved performance at 12-month testing, but had little change between 12- and 48-month testing. Conversely, individuals who scored high at baseline did not significantly change between baseline and 12-month testing, but improved between 12- and 48-month testing. RBANS scores did not significantly change over time.

CONCLUSIONS

These results suggest that the MoCA may be susceptible to practice effects, particularly between the first and second administrations. These practice effects should be taken into consideration when repeatedly employing the MoCA to screen for cognitive status in healthy older adults.