Browsing by Author "Paulsen, Jane S."
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Item Analysis of longitudinal censored semicontinuous data with application to the study of executive dysfunction: the Towers Task(Sage, 2017) Lourens, Spencer; Zhang, Ying; Long, Jeffrey D.; Paulsen, Jane S.; Biostatistics and Health Data Science, School of MedicineExecutive dysfunction is a deficiency in skills of planning and problem solving that characterizes many neuropsychiatric disorders. The Towers Task is a commonly used measure of planning and problem solving for assessing executive function. Towers Task data are usually zero-inflated and right-censored, and ignoring these features can result in biased inference for the disease characterization of executive dysfunction. In this manuscript, a mixed-effects model for longitudinal censored semicontinuous data is developed for analyzing longitudinal Towers Task data from the PREDICT-HD study. The model is contrasted with current practice and implications for general use are discussed.Item A clinical trial method to show delay of onset in Huntington disease(Wiley, 2019-02) Paulsen, Jane S.; Lourens, Spencer; Kieburtz, Karl; Zhang, Ying; Biostatistics, School of Public HealthBackground: Disease-modifying clinical trials in persons without symptoms are often limited in methods to assess the impact associated with experimental therapeutics. This study suggests sample enrichment approaches to facilitate preventive trials to delay disease onset in individuals with the dominant gene for Huntington disease. Methods: Using published onset prediction indexes, we conducted the receiver operating curve analysis for diagnosis within a 3-year clinical trial time frame. We determined optimal cut points on the indexes for participant recruitment and then conducted sample size and power calculations to detect varying effect sizes for treatment efficacy in reducing 3-year rates of disease onset (or diagnosis). Results: Area under the curve for 3 onset prediction indexes all demonstrated excellent value in sample enrichment methodology, with the best-performing index being the multivariate risk score (MRS). Conclusions: This study showed that conducting an intervention trial in premanifest and prodromal individuals with the gene expansion for Huntington disease is highly feasible using sample enrichment recruitment methods. Ongoing natural history studies are highly likely to indicate additional markers of disease prior to diagnosis. Statistical modeling of identified markers can facilitate participant enrichment to increase the likelihood of detecting a difference between treatment arms in a cost-effective and efficient manner. Such variations may expedite translation of emerging therapies to persons in an earlier phase of the disease.Item Effect of Deutetrabenazine on Chorea Among Patients With Huntington Disease A Randomized Clinical Trial(2016-07) Frank, Samuel; Testa, Claudia M.; Stamler, David; Kayson, Elise; Davis, Charles; Edmondson, Mary C.; Kinel, Shari; Leavitt, Blair; Oakes, David; O'Neill, Christine; Vaughan, Christina; Goldstein, Jody; Herzog, Margaret; Snively, Victoria; Whaley, Jacquelyn; Wong, Cynthia; Suter, Greg; Jankovic, Joseph; Jimenez-Shahed, Joohi; Hunter, Christine; Claassen, Daniel O.; Roman, Olivia C.; Sung, Victor; Smith, Jenna; Janicki, Sarah; Clouse, Ronda; Saint-Hilaire, Marie; Hohler, Anna; Turpin, Denyse; James, Raymond C.; Rodriguez, Ramon; Rizer, Kyle; Anderson, Karen E.; Heller, Hope; Carlson, Alexis; Criswell, Susan; Racette, Brad A.; Revilla, Fredy J.; Nucifora, Frederick, Jr.; Margolis, Russell L.; Ong, MaryJane; Mendis, Tilak; Mendis, Neila; Singer, Carlos; Quesada, Monica; Paulsen, Jane S.; Brashers-Krug, Thomas; Miller, Amanda; Kerr, Jane; Dubinsky, Richard M.; Gray, Carolyn; Factor, Stewart A.; Sperin, Elaine; Molho, Eric; Eglow, Mary; Evans, Sharon; Kumar, Rajeev; Reeves, Christina; Samii, Ali; Chouinard, Sylvain; Beland, Monica; Scott, Burton L.; Hickey, Patrick T.; Esmail, Sherali; Fung, Wai Lun Alan; Gibbons, Clare; Qi, Lina; Colcher, Amy; Hackmyer, Cory; McGarry, Andrew; Klos, Kevin; Gudesblatt, Mark; Fafard, Lori; Graffitti, Laura; Schneider, Daniel P.; Dhall, Rohit; Wojcieszek, Joanne M.; LaFaver, Kathrin; Duker, Andrew; Neefus, Erin; Wilson-Perez, Hilary; Shprecher, David; Wall, Paola; Blindauer, Karen A.; Wheeler, Lynn; Boyd, James T.; Houston, Emily; Farbman, Eric S.; Agarwal, Pinky; Eberly, Shirley W.; Watts, Arthur; Tariot, Pierre N.; Feigin, Andrew; Evans, Scott; Beck, Chris; Orme, Constance; Edicola, Jon; Christopher, Emily; Department of Neurology, IU School of MedicineImportance Deutetrabenazine is a novel molecule containing deuterium, which attenuates CYP2D6 metabolism and increases active metabolite half-lives and may therefore lead to stable systemic exposure while preserving key pharmacological activity. Objective To evaluate efficacy and safety of deutetrabenazine treatment to control chorea associated with Huntington disease. Design, Setting, and Participants Ninety ambulatory adults diagnosed with manifest Huntington disease and a baseline total maximal chorea score of 8 or higher (range, 0-28; lower score indicates less chorea) were enrolled from August 2013 to August 2014 and randomized to receive deutetrabenazine (n = 45) or placebo (n = 45) in a double-blind fashion at 34 Huntington Study Group sites. Interventions Deutetrabenazine or placebo was titrated to optimal dose level over 8 weeks and maintained for 4 weeks, followed by a 1-week washout. Main Outcomes and Measures Primary end point was the total maximal chorea score change from baseline (the average of values from the screening and day-0 visits) to maintenance therapy (the average of values from the week 9 and 12 visits) obtained by in-person visits. This study was designed to detect a 2.7-unit treatment difference in scores. The secondary end points, assessed hierarchically, were the proportion of patients who achieved treatment success on the Patient Global Impression of Change (PGIC) and on the Clinical Global Impression of Change (CGIC), the change in 36-Item Short Form– physical functioning subscale score (SF-36), and the change in the Berg Balance Test. Results Ninety patients with Huntington disease (mean age, 53.7 years; 40 women [44.4%]) were enrolled. In the deutetrabenazine group, the mean total maximal chorea scores improved from 12.1 (95% CI, 11.2-12.9) to 7.7 (95% CI, 6.5-8.9), whereas in the placebo group, scores improved from 13.2 (95% CI, 12.2-14.3) to 11.3 (95% CI, 10.0-12.5); the mean between-group difference was –2.5 units (95% CI, –3.7 to –1.3) (P < .001). Treatment success, as measured by the PGIC, occurred in 23 patients (51%) in the deutetrabenazine group vs 9 (20%) in the placebo group (P = .002). As measured by the CGIC, treatment success occurred in 19 patients (42%) in the deutetrabenazine group vs 6 (13%) in the placebo group (P = .002). In the deutetrabenazine group, the mean SF-36 physical functioning subscale scores decreased from 47.5 (95% CI, 44.3-50.8) to 47.4 (44.3-50.5), whereas in the placebo group, scores decreased from 43.2 (95% CI, 40.2-46.3) to 39.9 (95% CI, 36.2-43.6), for a treatment benefit of 4.3 (95% CI, 0.4 to 8.3) (P = .03). There was no difference between groups (mean difference of 1.0 unit; 95% CI, –0.3 to 2.3; P = .14), for improvement in the Berg Balance Test, which improved by 2.2 units (95% CI, 1.3-3.1) in the deutetrabenazine group and by 1.3 units (95% CI, 0.4-2.2) in the placebo group. Adverse event rates were similar for deutetrabenazine and placebo, including depression, anxiety, and akathisia. Conclusions and Relevance Among patients with chorea associated with Huntington disease, the use of deutetrabenazine compared with placebo resulted in improved motor signs at 12 weeks. Further research is needed to assess the clinical importance of the effect size and to determine longer-term efficacy and safety.Item Genome-wide significance for a modifier of age at neurological onset in Huntington's Disease at 6q23-24: the HD MAPS study(BioMed Central, 2006-08-17) Li, Jian-Liang; Hayden, Michael R.; Warby, Simon C.; Durr, Alexandra; Morrison, Patrick J.; Nance, Martha; Ross, Christopher A.; Margolis, Russell L.; Rosenblatt, Adam; Squitieri, Ferdinando; Frati, Luigi; Gómez-Tortosa, Estrella; Ayuso García, Carmen; Suchowersky, Oksana; Klimek, Mary Lou; Trent, Ronald J.A.; McCusker, Elizabeth; Novelletto, Andrea; Frontali, Marina; Paulsen, Jane S.; Jones, Randi; Ashizawa, Tetsuo; Lazzarini, Alice; Wheeler, Vanessa C.; Prakash, Ranjana; Xu, Gang; Djoussé, Luc; Medicine, School of MedicineBackground Age at onset of Huntington's disease (HD) is correlated with the size of the abnormal CAG repeat expansion in the HD gene; however, several studies have indicated that other genetic factors also contribute to the variability in HD age at onset. To identify modifier genes, we recently reported a whole-genome scan in a sample of 629 affected sibling pairs from 295 pedigrees, in which six genomic regions provided suggestive evidence for quantitative trait loci (QTL), modifying age at onset in HD. Methods In order to test the replication of this finding, eighteen microsatellite markers, three from each of the six genomic regions, were genotyped in 102 newly recruited sibling pairs from 69 pedigrees, and data were analyzed, using a multipoint linkage variance component method, in the follow-up sample and the combined sample of 352 pedigrees with 753 sibling pairs. Results Suggestive evidence for linkage at 6q23-24 in the follow-up sample (LOD = 1.87, p = 0.002) increased to genome-wide significance for linkage in the combined sample (LOD = 4.05, p = 0.00001), while suggestive evidence for linkage was observed at 18q22, in both the follow-up sample (LOD = 0.79, p = 0.03) and the combined sample (LOD = 1.78, p = 0.002). Epistatic analysis indicated that there is no interaction between 6q23-24 and other loci. Conclusion In this replication study, linkage for modifier of age at onset in HD was confirmed at 6q23-24. Evidence for linkage was also found at 18q22. The demonstration of statistically significant linkage to a potential modifier locus opens the path to location cloning of a gene capable of altering HD pathogenesis, which could provide a validated target for therapeutic development in the human patient.Item Longitudinal diffusion changes in prodromal and early HD: Evidence of white-matter tract deterioration(Wiley, 2017-03) Shaffer, Joseph J.; Ghayoor, Ali; Long, Jeffrey D.; Kim, Regina Eun-Young; Lourens, Spencer; O’Donnell, Lauren J.; Westin, Carl-Fredrik; Rathi, Yogesh; Magnotta, Vincent; Paulsen, Jane S.; Johnson, Hans J.; Biostatistics, School of Public HealthINTRODUCTION: Huntington's disease (HD) is a genetic neurodegenerative disorder that primarily affects striatal neurons. Striatal volume loss is present years before clinical diagnosis; however, white matter degradation may also occur prior to diagnosis. Diffusion-weighted imaging (DWI) can measure microstructural changes associated with degeneration that precede macrostructural changes. DWI derived measures enhance understanding of degeneration in prodromal HD (pre-HD). METHODS: As part of the PREDICT-HD study, N = 191 pre-HD individuals and 70 healthy controls underwent two or more (baseline and 1-5 year follow-up) DWI, with n = 649 total sessions. Images were processed using cutting-edge DWI analysis methods for large multicenter studies. Diffusion tensor imaging (DTI) metrics were computed in selected tracts connecting the primary motor, primary somato-sensory, and premotor areas of the cortex with the subcortical caudate and putamen. Pre-HD participants were divided into three CAG-Age Product (CAP) score groups reflecting clinical diagnosis probability (low, medium, or high probabilities). Baseline and longitudinal group differences were examined using linear mixed models. RESULTS: Cross-sectional and longitudinal differences in DTI measures were present in all three CAP groups compared with controls. The high CAP group was most affected. CONCLUSIONS: This is the largest longitudinal DWI study of pre-HD to date. Findings showed DTI differences, consistent with white matter degeneration, were present up to a decade before predicted HD diagnosis. Our findings indicate a unique role for disrupted connectivity between the premotor area and the putamen, which may be closely tied to the onset of motor symptoms in HD. Hum Brain Mapp 38:1460-1477, 2017. © 2017 Wiley Periodicals, Inc.Item Mild Cognitive Impairment as an Early Landmark in Huntington's Disease(Frontiers Media, 2021-07-07) Zhang, Ying; Zhou, Junyi; Gehl, Carissa R.; Long, Jeffrey D.; Johnson, Hans; Magnotta, Vincent A.; Sewell, Daniel; Shannon, Kathleen; Paulsen, Jane S.; Biostatistics and Health Data Science, Richard M. Fairbanks School of Public HealthAs one of the clinical triad in Huntington's disease (HD), cognitive impairment has not been widely accepted as a disease stage indicator in HD literature. This work aims to study cognitive impairment thoroughly for prodromal HD individuals with the data from a 12-year observational study to determine whether Mild Cognitive Impairment (MCI) in HD gene-mutation carriers is a defensible indicator of early disease. Prodromal HD gene-mutation carriers evaluated annually at one of 32 worldwide sites from September 2002 to April 2014 were evaluated for MCI in six cognitive domains. Linear mixed-effects models were used to determine age-, education-, and retest-adjusted cut-off values in cognitive assessment for MCI, and then the concurrent and predictive validity of MCI was assessed. Accelerated failure time (AFT) models were used to determine the timing of MCI (single-, two-, and multiple-domain), and dementia, which was defined as MCI plus functional loss. Seven hundred and sixty-eight prodromal HD participants had completed all six cognitive tasks, had MRI, and underwent longitudinal assessments. Over half (i.e., 54%) of the participants had MCI at study entry, and half of these had single-domain MCI. Compared to participants with intact cognitive performances, prodromal HD with MCI had higher genetic burden, worsened motor impairment, greater brain atrophy, and a higher likelihood of estimated HD onset. Prospective longitudinal study of those without MCI at baseline showed that 48% had MCI in subsequent visits and data visualization suggested that single-domain MCI, two-domain MCI, and dementia represent appropriate cognitive impairment staging for HD gene-mutation carriers. Findings suggest that MCI represents an early landmark of HD and may be a sensitive enrichment variable or endpoint for prodromal clinical trials of disease modifying therapeutics.Item Motor onset and diagnosis in Huntington disease using the diagnostic confidence level(Springer, 2015-12) Liu, Dawei; Long, Jeffrey D.; Zhang, Ying; Raymond, Lynn A.; Marder, Karen; Rosser, Anne; McCusker, Elizabeth A.; Mills, James A.; Paulsen, Jane S.; Department of Biostatistics, Richard M. Fairbanks School of Public HealthHuntington disease (HD) is a neurodegenerative disorder characterized by motor dysfunction, cognitive deterioration, and psychiatric symptoms, with progressive motor impairments being a prominent feature. The primary objectives of this study are to delineate the disease course of motor function in HD, to provide estimates of the onset of motor impairments and motor diagnosis, and to examine the effects of genetic and demographic variables on the progression of motor impairments. Data from an international multisite, longitudinal observational study of 905 prodromal HD participants with cytosine-adenine-guanine (CAG) repeats of at least 36 and with at least two visits during the followup period from 2001 to 2012 was examined for changes in the diagnostic confidence level from the Unified Huntington's Disease Rating Scale. HD progression from unimpaired to impaired motor function, as well as the progression from motor impairment to diagnosis, was associated with the linear effect of age and CAG repeat length. Specifically, for every 1-year increase in age, the risk of transition in diagnostic confidence level increased by 11% (95% CI 7-15%) and for one repeat length increase in CAG, the risk of transition in diagnostic confidence level increased by 47% (95% CI 27-69%). Findings show that CAG repeat length and age increased the likelihood of the first onset of motor impairment as well as the age at diagnosis. Results suggest that more accurate estimates of HD onset age can be obtained by incorporating the current status of diagnostic confidence level into predictive models.Item Phenotype Characterization of HD Intermediate Alleles in PREDICT-HD(IOS Press, 2016-12-15) Downing, Nancy R.; Lourens, Spencer; De Soriano, Isabella; Long, Jeffrey D.; Paulsen, Jane S.; PREDICT-HD Investigators and Coordinators of the Huntington Study Group; Biostatistics, School of Public HealthBACKGROUND: Huntington disease (HD) is a neurodegenerative disease caused by a CAG repeat expansion on chromosome 4. Pathology is associated with CAG repeat length. Prior studies examining people in the intermediate allele (IA) range found subtle differences in motor, cognitive, and behavioral domains compared to controls. OBJECTIVE: The purpose of this study was to examine baseline and longitudinal differences in motor, cognitive, behavioral, functional, and imaging outcomes between persons with CAG repeats in three ranges: normal (≤26), intermediate (27-35), and reduced penetrance (36-39). METHODS: We examined longitudinal data from 389 participants in three allele groups: 280 normal controls (NC), 21 intermediate allele [IA], and 88 reduced penetrance [RP]. We used linear mixed models to identify differences in baseline and longitudinal outcomes between groups. Three models were tested: 1) no baseline or longitudinal differences; 2) baseline differences but no longitudinal differences; and 3) baseline and longitudinal differences. RESULTS: Model 1 was the best fitting model for most outcome variables. Models 2 and 3 were best fitting for some of the variables. We found baseline and longitudinal trends of declining performance across increasing CAG repeat length groups, but no significant differences between the NC and IA groups. CONCLUSION: We did not find evidence to support differences in the IA group compared to the NC group. These findings are limited by a small IA sample size.