Health Centers and Value-Based Payment: A Framework for Health Center Payment Reform and Early Experiences in Medicaid Value-Based Payment in Seven States.

Policy Points As essential access points to primary care for almost 29 million US patients, of whom 47% are Medicaid enrollees, health centers are positioned to implement the population health management necessary in value-based payment (VBP) contracts. Primary care payment reform requires multiple payment methodologies used together to provide flexibility to care providers, encourage investments in infrastructure and new services, and offer incentives for achieving better health outcomes. State policy and significant financial incentives from Medicaid agencies and Medicaid managed care plans will likely be required to increase health center participation in VBP, which is consistent with broader state efforts to expand investment in primary care. CONTEXT: Efforts are ongoing to advance value-based payment (VBP), and health centers serve as essential access points to comprehensive primary care services for almost 29 million people in the United States. Therefore, it is important to assess the levels of health center participation in VBP, types of VBP contracts, characteristics of health centers participating in VBP, and variations in state policy environments that influence VBP participation. METHODS: This mixed methods study combined qualitative research on state policy environments and health center participation in VBP with quantitative analysis of Uniform Data System and health center financial data in seven vanguard states: Oregon, Washington, California, Colorado, New York, Hawaii, and Kentucky. VBP contracts were classified into three layers: base payments being transformed from visit-based to population-based (Layer 1), infrastructure and care coordination payments (Layer 2), and performance incentive payments (Layer 3). FINDINGS: Health centers in all seven states participated in Layer 2 and Layer 3 VBP, with VBP participation growing from 35% to 58% of all health centers in these states from 2013 to 2017. Among participating health centers, the average percentage of Medicaid revenue received as Layer 2 and Layer 3 VBP rose from 6.4% in 2013 to 9.1% in 2017. Oregon and Washington health centers participating in Layer 1 payment reforms received most of their Medicaid revenue in VBP. In 2017, VBP participation was associated with larger health center size in four states (P <.05), and higher average number of days cash on hand (P <.05) in three states. CONCLUSIONS: A multilayer payment model is useful for implementing and monitoring VBP adoption among health centers. State policy, financial incentives from Medicaid agencies and Medicaid managed plans, and health center-Medicaid collaboration under strong primary care association and health center leadership will likely be required to increase health center participation in VBP.

Public Perceptions and Information Needs of VCA Transplantation and Donation: A Mixed Methods Study.

Vascularized Composite Allotransplantation (VCA) involves transplantation of multiple tissues from a donor to a recipient (e.g., skin, muscle, bone). Little is known about the US public's perceptions of and attitudes toward VCA organ donation. This multi-site, cross-sectional, mixed methods study involved focus groups and surveys to assess members of the general public's attitudes about VCA, and willingness and barriers to donate VCA organs. Qualitative data were analyzed by thematic analysis; quantitative data were analyzed by descriptive statistics. In focus groups (n = 6, 42 participants), most participants were female (57%) and Black (62%) with mean age of 42.6 years. Three main themes emerged: 1) awareness and perceptions of VCA, 2) purpose of VCA donation, 3) and barriers to VCA donation. Participants had heard little about VCA and sought information about VCA donation. Participants perceived VCA as challenging their concepts of "normality" and voiced concerns that VCA would create "Frankenstein[s]." Barriers to VCA donation included disruptions to end-of-life arrangements and information gaps regarding the donation process. Participants reported moderate to high willingness to donate their hands (69%) and face (50%) Public education efforts should address the specific needs and concerns of the public to facilitate VCA donation and family authorization.

A longitudinal study of magnetic resonance spectroscopy Huntington's disease biomarkers.

Putaminal metabolites examined using cross-sectional magnetic resonance spectroscopy (MRS) can distinguish pre-manifest and early Huntington's Disease (HD) individuals from controls. An ideal biomarker, however, will demonstrate longitudinal change over short durations. The objective here was to evaluate longitudinal in vivo brain metabolite profiles in HD over 24 months. Eighty-four participants (30 controls, 25 pre-manifest HD, 29 early HD) recruited as part of TRACK-HD were imaged at baseline, 12 months, and 24 months using 3T MRS of left putamen. Automated putaminal volume measurement was performed simultaneously. To quantify partial volume effects, spectroscopy was performed in a second, white matter voxel adjacent to putamen in six subjects. Subjects underwent TRACK-HD motor assessment. Statistical analyses included linear regression and one-way analysis of variance (ANOVA). At all time-points N-acetyl aspartate and total N-acetyl aspartate (NAA), neuronal integrity markers, were lower in early HD than in controls. Total NAA was lower in pre-manifest HD than in controls, whereas the gliosis marker myo-inositol (MI) was robustly elevated in early HD. Metabolites were stable over 24 months with no longitudinal change. Total NAA was not markedly different in adjacent white matter than putamen, arguing against partial volume confounding effects in cross-sectional group differences. Total NAA correlations with disease burden score suggest that this metabolite may be useful in identifying neurochemical responses to therapeutic agents. We demonstrate almost consistent group differences in putaminal metabolites in HD-affected individuals compared with controls over 24 months. Future work establishing spectroscopy as an HD biomarker should include multi-site assessments in large, pathologically diverse cohorts.

Reliability and factor structure of the Short Problem Behaviors Assessment for Huntington's disease (PBA-s) in the TRACK-HD and REGISTRY studies.

The authors report the inter-rater reliability and factor structure of the Short Problem Behaviors Assessment (PBA-s), a semistructured interview to measure severity and frequency of behavioral problems in Huntington's disease. Video recordings of 410 PBA-s interviews were rescored by an independent rater, and Cohen's kappa calculated to assess inter-rater reliability. The mean kappa was 0.74 for severity and 0.76 for frequency scores, whereas weighted kappa (allowing scores to differ by 1 point) was 0.94 for severity and 0.92 for frequency scores. The results of factor analysis were consistent with previous studies using other measures. The authors conclude that the PBA-s is a reliable measure.

Supporting new graduate professional development: a clinical learning framework.

BACKGROUND/AIMS: New graduate occupational therapists are required to competently deliver health-care practices within complex care environments. An occupational therapy clinical education programme within a large public sector health service sought to investigate methods to support new graduates in their clinical learning and professional development. METHODS: Three cycles of an insider action research approach each using the steps of planning, action, critical observation and reflection were undertaken to investigate new graduate learning strategies, develop a learning framework and pilot its utility. Qualitative research methods were used to analyse data gathered during the action research cycles. RESULTS: Action research identified variations in current practices to support new graduate learning and to the development of the Occupational Therapy Clinical Learning Framework (OTCLF). Investigation into the utility of the OTCLF revealed two themes associated with its implementation namely (i) contribution to learning goal development and (ii) compatibility with existing learning supports. CONCLUSIONS AND SIGNIFICANCE OF THE STUDY: The action research cycles aimed to review current practices to support new graduate learning. The learning framework developed encourages reflection to identify learning needs and the review, discussion of, and engagement in, goal setting and learning strategies. Preliminary evidence indicates that the OTCLF has potential as an approach to guide new graduate goal development supported by supervision. Future opportunity to implement a similar learning framework in other allied health professions was identified, enabling a continuation of the cyclical nature of enquiry, integral to this research approach within the workplace.

Examining the inter-rater and test-retest reliability of the Student Practice Evaluation Form-Revised (SPEF-R) for occupational therapy students.

BACKGROUND/AIM: The Student Practice Evaluation Form-Revised Edition (SPEF-R) is widely used in Australian universities to evaluate occupational therapy students' performance in practice education. Reliable completion of the SPEF-R by practice educators is critical for students and universities from a quality assurance perspective. This study used standardised video vignettes to examine the inter-rater and test-retest reliability of practice educators when completing the SPEF-R. METHODS: Nine vignettes were developed with three levels of student performance (below expectations, adequate-to-proficient, and outstanding) for each of three scenarios which depicted a multidisciplinary team meeting, a supervision session, and a home visit respectively. Seventy-five occupational therapy practice educators viewed the vignettes and completed an online survey to rate student performance in each vignette using five selected SPEF-R items and using the five-point rating scale. Twenty of these practice educators completed the rating process twice for test-retest reliability purposes. Percentage agreement, t-tests and Rasch Measurement Model were used for analysis. RESULTS: Practice educators exhibited consistent ratings on most of the SPEF-R items, except for rating adequate-to-proficient student performance on three items for inter-rater reliability and eight items for test-retest reliability. Rasch analysis found that the majority of practice educators (96-98.7%) exhibited consistency in their use of the SPEF-R rating scales. Practice educators also demonstrated satisfactory test-retest agreement of severity/leniency in rating student performance in the multidisciplinary team meeting scenario. CONCLUSION: The study findings suggest that the SPEF-R could be used reliably and interpreted consistently by practice educators with diverse backgrounds and levels of experience.

Student Practice Evaluation Form-Revised Edition online comment bank: development and reliability analysis.

BACKGROUND/AIM: The reliable evaluation of occupational therapy students completing practice education placements along with provision of appropriate feedback is critical for both students and for universities from a quality assurance perspective. This study describes the development of a comment bank for use with an online version of the Student Practice Evaluation Form-Revised Edition (SPEF-R Online) and investigates its reliability. METHODS: A preliminary bank of 109 individual comments (based on previous students' placement performance) was developed via five stages. These comments reflected all 11 SPEF-R domains. A purpose-designed online survey was used to examine the reliability of the comment bank. A total of 37 practice educators returned surveys, 31 of which were fully completed. Participants were asked to rate each individual comment using the five-point SPEF-R rating scale. RESULTS: One hundred and two of 109 comments demonstrated satisfactory agreement with their respective default ratings that were determined by the development team. At each domain level, the intra-class correlation coefficients (ranging between 0.86 and 0.96) also demonstrated good to excellent inter-rater reliability. There were only seven items that required rewording prior to inclusion in the final SPEF-R Online comment bank. CONCLUSION: The development of the SPEF-R Online comment bank offers a source of reliable comments (consistent with the SPEF-R rating scale across different domains) and aims to assist practice educators in providing reliable and timely feedback to students in a user-friendly manner.

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.

Factors associated with federally qualified health center financial performance.

OBJECTIVES: To understand factors associated with federally qualified health center (FQHC) financial performance. STUDY DESIGN: We used multivariate linear regression to identify correlates of health center financial performance. We examined six measures of health center financial performance across four domains: margin (operating margin), liquidity (days cash on hand [DCOH], current ratio), solvency (debt-to-equity ratio), and others (net patient accounts receivable days, personnel-related expenses). We examined potential correlates of financial performance, including characteristics of the patient population, health center organization, and location/geography. DATA SOURCES: We use 2012-2017 Uniform Data System (UDS) files, financial audit data from Capital link, and publicly available data. DATA COLLECTION/EXTRACTION METHODS: We focused on health centers in the 50 US states and District of Columbia, which reported information to UDS for at least 1 year between 2012 and 2017 and had Capital link financial audit data. PRINCIPAL FINDINGS: FQHC financial performance generally improved over the study period, especially from 2015 to 2017. In multivariate regression models, a higher percentage of Medicaid patients was associated with better margins (operating margin: 0.06, p < 0.001), liquidity (DCOH: 0.67, p < 0.001; current ratio: 0.28, p = 0.001), and solvency (debt-to equity ratio: -0.08, p = 0.004). Moreover, a staffing mix comprised of more nonphysician providers was associated with better margin (operating margin: 0.21, p = 0.001) and liquidity (current ratio: 1.12, p < 0.001) measures. Patient-centered medical home (PCMH) recognition was also associated with better liquidity (DCOH: 19.01, p < 0.001; current ratio: 4.68, p = 0.014) and solvency (debt-to-equity ratio: -2.03, p < 0.001). CONCLUSIONS: The financial health of FQHCs improved with provisions of the Affordable Care Act, which included significant Medicaid expansion and direct funding support for health centers. FQHC financial health was also associated with key staffing and operating characteristics of health centers. Maintaining the financial health of FQHCs is critical to their ability to continuously provide affordable and high-quality care in medically underserved areas.

The structural involvement of the cingulate cortex in premanifest and early Huntington's disease.

The impact of Huntington's disease neuropathology on the structure of the cingulate is uncertain, with evidence of both cortical enlargement and atrophy in this structure in early clinical disease. We sought to determine differences in cingulate volume between premanifest Huntington's disease and early Huntington's disease groups compared with controls using detailed manual measurements. Thirty controls, 30 subjects with premanifest Huntington's disease, and 30 subjects with early Huntington's disease were selected from the Vancouver site of the TRACK-HD study. Subjects underwent 3 Tesla magnetic resonance imaging and motor, cognitive, and neuropsychiatric assessment. The cingulate was manually delineated and subdivided into rostral, caudal, and posterior segments. Group differences in volume and associations with performance on 4 tasks thought to utilize cingulate function were examined, with adjustment for appropriate covariates. Cingulate volumes were, on average, 1.7 mL smaller in early Huntington's disease (P=.001) and 0.9 mL smaller in premanifest Huntington's disease (P=.1) compared with controls. Smaller volumes in subsections of the cingulate were associated with impaired recognition of negative emotions (P=.04), heightened depression (P=.009), and worse visual working memory performance (P=.01). There was no evidence of associations between volume and ability on a performance-monitoring task. This study disputes previous findings of enlargement of the cingulate cortex in Huntington's disease and instead suggests that the cingulate undergoes structural degeneration during early Huntington's disease with directionally consistent, nonsignificant differences seen in premanifest Huntington's disease. Cingulate atrophy may contribute to deficits in mood, emotional processing, and visual working memory in Huntington's disease.

A Flipped Classroom and Case-Based Curriculum to Prepare Medical Students for Vaccine-Related Conversations with Parents.

INTRODUCTION: Immunizations, one of the most significant public health successes in the last century, have recently been met with a resistance that has resulted in populations with falling immunity and outbreaks of vaccine-preventable diseases. In response to this, we conducted a needs assessment of medical students at the University of California, Los Angeles David Geffen School of Medicine to assess attitudes towards vaccines, knowledge of vaccines and vaccine-preventable diseases, and confidence in discussing vaccines. The results informed the development of this interactive, flipped-classroom and case-based curriculum for third-year pediatric clerkship students. METHODS: In our two-part curriculum, students independently view a short podcast with an overview of vaccines and vaccine-preventable diseases, then participate in a case-based workshop. For the workshop, students divide into small groups and are presented with a case-based scenario surrounding a child with a parent who has concerns about recommended vaccines. Students discuss the case in small groups, find answers to directed questions, and present the case and findings to the larger group, with specific focus on their approach to the vaccine hesitant parent. RESULTS: Anonymous student evaluations revealed that 93% of students enjoyed learning from this flipped classroom and case-based format. Likewise, 98% of students felt more confident in their approach to vaccine discussions. DISCUSSION: Vaccine hesitancy is becoming an increasingly common and worrisome problem. Our curriculum provides students with knowledge about the importance of childhood immunizations as well as an opportunity to practice addressing common concerns and misconceptions they will encounter in clinical settings.

Establishing the Validity and Reliability of the Student Practice Evaluation Form-Revised (SPEF-R) in Occupational Therapy Practice Education: A Rasch Analysis.

This study investigated construct validity and internal consistency of the Student Practice Evaluation Form-Revised Edition Package (SPEF-R) which evaluates students' performance on practice education placements. The SPEF-R has 38 items covering eight domains, and each item is rated on a 5-point rating scale. Data from 125 students' final placement evaluations in their final year study were analyzed using the Rasch measurement model. The SPEF-R exhibited satisfactory rating scale performance and unidimensionality across the eight domains, providing construct validity evidence. Only 2 items misfit Rasch model's expectations (both related to students' performance with client groups, which were often rated as not observed). Additionally, the internal consistency of each SPEF-R domain was found to be excellent (Cronbach's α = .86 to .91) and all individual items had reasonable to excellent item-total correlation coefficients. The study results indicate that the SPEF-R can be used with confidence to evaluate students' performance during placements, but continued validation and refinement are required.

Patterns of dye coupling in lumbar motor nuclei of the rat.

Gap junctions exist on motoneurons of the spinal nucleus of the bulbocavernosus (SNB) and the dorsolateral nucleus (DLN), both sexually dimorphic motor nuclei in the lumbar spinal cord of the rat. In addition, messenger RNA for gap junction proteins is expressed in motoneurons of the retrodorsolateral nucleus (RDLN), a nondimorphic spinal motor nucleus that innervates a muscle of the foot. Gap junctions on SNB and DLN motoneurons are androgen sensitive; the number and size of gap junctions decrease following castration, a change that can be reversed with exogenous testosterone replacement. In contrast, RDLN gap junction mRNA levels remain constant throughout hormone manipulation. In this study, dye coupling was used to examine patterns of gap junction-mediated connectivity in these three lumbar spinal motor nuclei. Injection of dye into single motoneurons resulted in spatially extensive labeling of neighboring cells in all three nuclei; significantly more coupling was observed in the sexually dimorphic nuclei than in the RDLN. Dye-coupled clusters of cells included motoneurons and interneurons; coupling was bilateral in the SNB. Treatment with oleamide, a gap junction blocker, completely attenuated labeling. In all nuclei, androgen manipulation did not alter the number, identity, or distribution of coupled cells. Thus, sexually dimorphic nuclei in the spinal cord exhibit greater dye coupling than do nondimorphic populations, and the patterns of connectivity are insensitive to androgen despite modification of their number and size.

Egocentric reference frame bias in the palmar haptic perception of surface orientation.

The effect of egocentric reference frames on palmar haptic perception of orientation was investigated in vertically separated locations in a sagittal plane. Reference stimuli to be haptically matched were presented either haptically (to the contralateral hand) or visually. As in prior investigations of haptic orientation perception, a strong egocentric bias was found, such that haptic orientation matches made in the lower part of personal space were much lower (i.e., were perceived as being higher) than those made at eye level. The same haptic bias was observed both when the reference surface to be matched was observed visually and when bimanual matching was used. These findings support the conclusion that, despite the presence of an unambiguous allocentric (gravitational) reference frame in vertical planes, haptic orientation perception in the sagittal plane reflects an egocentric bias.

The potential of composite cognitive scores for tracking progression in Huntington's disease.

BACKGROUND: Composite scores derived from joint statistical modelling of individual risk factors are widely used to identify individuals who are at increased risk of developing disease or of faster disease progression. OBJECTIVE: We investigated the ability of composite measures developed using statistical models to differentiate progressive cognitive deterioration in Huntington's disease (HD) from natural decline in healthy controls. METHODS: Using longitudinal data from TRACK-HD, the optimal combinations of quantitative cognitive measures to differentiate premanifest and early stage HD individuals respectively from controls was determined using logistic regression. Composite scores were calculated from the parameters of each statistical model. Linear regression models were used to calculate effect sizes (ES) quantifying the difference in longitudinal change over 24 months between premanifest and early stage HD groups respectively and controls. ES for the composites were compared with ES for individual cognitive outcomes and other measures used in HD research. The 0.632 bootstrap was used to eliminate biases which result from developing and testing models in the same sample. RESULTS: In early HD, the composite score from the HD change prediction model produced an ES for difference in rate of 24-month change relative to controls of 1.14 (95% CI: 0.90 to 1.39), larger than the ES for any individual cognitive outcome and UHDRS Total Motor Score and Total Functional Capacity. In addition, this composite gave a statistically significant difference in rate of change in premanifest HD compared to controls over 24-months (ES: 0.24; 95% CI: 0.04 to 0.44), even though none of the individual cognitive outcomes produced statistically significant ES over this period. CONCLUSIONS: Composite scores developed using appropriate statistical modelling techniques have the potential to materially reduce required sample sizes for randomised controlled trials.

Emotional face recognition deficits and medication effects in pre-manifest through stage-II Huntington's disease.

Facial emotion recognition impairments have been reported in Huntington's disease (HD). However, the nature of the impairments across the spectrum of HD remains unclear. We report on emotion recognition data from 344 participants comprising premanifest HD (PreHD) and early HD patients, and controls. In a test of recognition of facial emotions, we examined responses to six basic emotional expressions and neutral expressions. In addition, and within the early HD sample, we tested for differences on emotion recognition performance between those 'on' vs. 'off' neuroleptic or selective serotonin reuptake inhibitor (SSRI) medications. The PreHD groups showed significant (p<0.05) impaired recognition, compared to controls, on fearful, angry and surprised faces; whereas the early HD groups were significantly impaired across all emotions including neutral expressions. In early HD, neuroleptic use was associated with worse facial emotion recognition, whereas SSRI use was associated with better facial emotion recognition. The findings suggest that emotion recognition impairments exist across the HD spectrum, but are relatively more widespread in manifest HD than in the premanifest period. Commonly prescribed medications to treat HD-related symptoms also appear to affect emotion recognition. These findings have important implications for interpersonal communication and medication usage in HD.

Quality of life in Huntington's disease: a comparative study investigating the impact for those with pre-manifest and early manifest disease, and their partners.

BACKGROUND: Given the multifaceted nature of this inherited neurodegenerative condition, typically affecting adults in mid-life, it is perhaps not surprising that studies indicate poorer Health Related Quality of Life (HrQoL) in those with the gene-expansion and, by association, in their families. OBJECTIVE: This study aimed to extend the current literature by exploring specific life domains, including at an earlier disease stage than usually reported in the HRQoL literature, and in a subgroup of gene-negative partners. METHODS: 355 participants from the TRACK-HD cohort (120 Controls, 118 Pre-HD and 117 early-HD) completed standardised self-report measures of HrQoL (SF36 and QoLI), underwent clinical assessments of capacity and motor function (UHDRS), semi structured interviews assessing neuropsychiatric symptoms (PBA-s), completed paper and computerized cognitive tasks and assessment of behaviours associated with damage to frontal brain circuits (FrSBe). RESULTS: Each gene-expanded group scored statistically significantly lower than gene-negative sibling controls on the SF36 General Health subscale; neuropsychiatric symptoms and executive dysfunction were associated with reduced HrQoL. Those with Stage II disease reported statistically significantly lower HrQoL than gene-negative controls across physical, emotional and social life domains. Those partnered with manifest participants reported lower HrQoL in the social domain compared to those partnered with at-risk participants furthest from disease onset; and perseverative symptoms in manifest partners were found to be related to lower HrQoL in their gene-negative partners. HrQoL in gene-negative partners of pre-manifest individuals was associated with pre-manifest individuals' neuropsychiatric and cognitive function. CONCLUSIONS: Understanding the nature and timing of disruption to the HrQoL in people who are pre-manifest and diagnosed with HD, and their gene-negative partners, can inform the development of appropriate strategies and interventions.

Visual Working Memory Impairment in Premanifest Gene-Carriers and Early Huntington's Disease.

Working memory deficits have been found in Huntington's disease (HD) and in a small group of premanifest (PreHD) gene-carriers. However, the nature and extent of these deficits are unknown. In a large cross-sectional study, we aimed to determine the degree of visuospatial working memory dysfunction across multiple stages of HD. Specifically, visuospatial working memory capacity and response times across various degrees of difficulty were examined, as well as the relationship between visuospatial working memory and motor dysfunction. We examined 62 PreHD-A gene-carriers (>10.8 years from estimated disease onset), 58 PreHD-B gene-carriers (<10.8 years from estimated disease onset), 77 stage-1 HD patients (HD1), 44 stage-2 HD patients (HD2), and 122 healthy controls. Participants viewed coloured squares (in sets of 3, 5 and 7) on a screen and were to decide whether on a subsequent screen the encircled square has changed colour. Accuracy and response times were recorded. Compared to controls, significant group differences in visuospatial working memory capacity (accuracy) were seen in PreHD-B, HD1 and HD2 groups across the difficulty levels. Significant group differences on response times were found for all groups (PreHD-A to HD2) compared to controls; the most difficult level producing the only group difference in speed between PreHD-A and controls. Accuracy and speed were positively correlated only in the HD groups. These findings suggest that visuospatial working memory impairments are detectable in both premanifest and manifest HD; the manifest HD showed evidence for a "worse-worse phenomenon" whereby reductions were present in both motor speed and accuracy.

Visuomotor integration deficits precede clinical onset in Huntington's disease.

OBJECTIVES: Visuomotor integration deficits have been documented in Huntington disease (HD), with disproportionately more impairment when direct visual feedback is unavailable. Visuomotor integration under direct and indirect visual feedback conditions has not been investigated in the stage before clinical onset ('premanifest'). However, given evidence of posterior cortical atrophy in premanifest HD, we predicted visuomotor integration would be adversely affected, with greater impairment under conditions of indirect visual feedback. METHODS: 239 subjects with the HD CAG expansion, ranging from more than a decade before predicted clinical onset until early stage disease, and 122 controls, completed a circle-tracing task, which included both direct and indirect visual feedback conditions. Measures included accuracy, speed, and speed of error detection and correction. Using brain images acquired with 3T magnetic resonance imaging (MRI), we generated grey and white matter volumes with voxel-based morphometry, and analyzed correlations with circle-tracing performance. RESULTS: Compared with controls, early HD was associated with lower accuracy and slower performance in both circle-tracing conditions. Premanifest HD was associated with lower accuracy in both conditions and fewer rotations in the direct condition. Comparing performance in the indirect condition with the direct condition, HD gene expansion-carriers exhibited a disproportionate increase in errors relative to controls. Premanifest and early HD groups required longer to detect and correct errors, especially in the indirect condition. Slower performance in the indirect condition was associated with lower grey matter volumes in the left somatosensory cortex in VBM analyses. CONCLUSIONS: Visuomotor integration deficits are evident many years before the clinical onset of HD, with deficits in speed, accuracy, and speed of error detection and correction. The visuomotor transformation demands of the indirect condition result in a disproportionate decrease in accuracy in the HD groups. Slower performance under indirect visual feedback was associated with atrophy of the left-hemisphere somatosensory cortex, which may reflect the proprioceptive demands of the task.