Rate of change in early Huntington's disease: a clinicometric analysis

Sensitive outcome measures for patients with Huntington's disease (HD) are required for future clinical trials. Longitudinal data were collected from a 3-year study of 379 patients suffering from early HD who were not treated by antipsychotics. Progression of UHDRS item scores was evaluated by linear regression and slope, whereas correlation coefficient, standard error, and P values were estimated on the basis of the data of eight evaluations from screening to study end (36 months). For the functional assessment dimension, the proportion of "no" responses at baseline and at study end was determined. Linear progression was observed for the motor score and for all three functional measures (i.e., functional assessment score, independence assessment score, and total functional capacity score). In contrast, there was little evidence for progression of the behavioral assessment score over the study period, whereas the cognitive assessment score was intermediate. Twenty-two motor-score items showed linear progression, with a slope of >0.003. These included all chorea items, finger tapping and pronation/supination (left and right), gait, tongue protrusion, and tandem walking. Different symptom domains and individual items evolved at different rates in this group of patients suffering from early HD. It may be possible to select sensitive items to create a simplified version of the UHDRS, which would be more efficient and more sensitive for the assessment of disease progression in clinical trials and natural history studies.     

Identification of an oculomotor biomarker of preclinical Huntington disease

The authors examined oculomotor function to identify a biomarker of disease progression in genetically confirmed preclinical and early clinical Huntington disease (HD). Initiation deficits of voluntary-guided, but not reflexive, saccades were characteristic of preclinical HD. Saccadic slowing and delayed reflexive saccades were demonstrated in clinical but not preclinical HD. Saccadic measures provide biomarkers of disease progression in both preclinical and early clinical stages of HD.     

Tongue force analysis assesses motor phenotype in premanifest and symptomatic Huntington's disease

Motor symptoms in Huntington's Disease (HD) are commonly assessed by the Unified Huntington's Disease Rating Scale‐Total Motor Score (UHDRS‐TMS). However, the UHDRS‐TMS is limited by interrater variability, its categorical nature, and insensitivity in premanifest subjects. More objective and quantitative measures of motor phenotype may complement the use of the UHDRS‐TMS as outcome measure and increase the power and sensitivity of clinical trials. Deficits in tongue protrusion are well acknowledged in HD and constitute a subitem of the UHDRS‐TMS. We, therefore, investigated whether objective and quantitative assessment of tongue protrusion forces (TPF) provides measures that (1) correlate to the severity of motor phenotype detected in the UHDRS‐TMS in symptomatic HD, (2) detect a motor phenotype in premanifest HD gene‐carriers, and (3) exhibit a correlation to the genotype as assessed by a disease burden score (based on CAG‐repeat length and age). Using a precalibrated force transducer, the ability of premanifest gene carriers (n = 15) and subjects with symptomatic HD (n = 20) to generate and maintain isometric TPF at three target force levels (0.25, 0.5, and 1.0 N) was assessed and compared with age‐matched controls (n = 20) in a cross‐sectional study. Measures of variability of TPF and tongue contact time distinguished controls, premanifest, and symptomatic HD groups and correlated to the UHDRS‐TMS and disease burden score, suggesting a strong genotype‐phenotype correlation. Group distinction was most reliable at the lowest target force level. We conclude that assessment of TPF may be a useful objective and quantitative marker of motor dysfunction in premanifest and symptomatic HD. © 2010 Movement Disorder Society     

An item response analysis of the motor and behavioral subscales of the unified Huntington's disease rating scale in huntington disease gene expansion carriers

Although the Unified Huntington's Disease Rating Scale (UHDRS) is widely used in the assessment of Huntington disease (HD), the ability of individual items to discriminate individual differences in motor or behavioral manifestations has not been extensively studied in HD gene expansion carriers without a motor‐defined clinical diagnosis (ie, prodromal‐HD or prHD). To elucidate the relationship between scores on individual motor and behavioral UHDRS items and total score for each subscale, a nonparametric item response analysis was performed on retrospective data from 2 multicenter longitudinal studies. Motor and behavioral assessments were supplied for 737 prHD individuals with data from 2114 visits (PREDICT‐HD) and 686 HD individuals with data from 1482 visits (REGISTRY). Option characteristic curves were generated for UHDRS subscale items in relation to their subscale score. In prHD, overall severity of motor signs was low, and participants had scores of 2 or above on very few items. In HD, motor items that assessed ocular pursuit, saccade initiation, finger tapping, tandem walking, and to a lesser extent, saccade velocity, dysarthria, tongue protrusion, pronation/supination, Luria, bradykinesia, choreas, gait, and balance on the retropulsion test were found to discriminate individual differences across a broad range of motor severity. In prHD, depressed mood, anxiety, and irritable behavior demonstrated good discriminative properties. In HD, depressed mood demonstrated a good relationship with the overall behavioral score. These data suggest that at least some UHDRS items appear to have utility across a broad range of severity, although many items demonstrate problematic features. © 2011 Movement Disorder Society     

Altered frontostriatal coupling in pre‐manifest Huntington’s disease: effects of increasing cognitive load

Background and purpose: Functional neuroimaging studies have suggested a dysfunction of prefrontal regions in clinically pre‐symptomatic individuals with the Huntington’s disease (HD) gene mutation (pre‐HD) during cognitive processing. The objective of this study was to test the impact of cognitive demand on prefrontal connectivity in pre‐HD individuals. Methods: Sixteen healthy controls and sixteen pre‐HD subjects were studied using functional MRI and a verbal working memory task with increasing cognitive load. Load‐dependent functional connectivity of the left dorsolateral prefrontal cortex (DLPFC) was investigated by means of psychophysiological interactions. Results: In pre‐HD subjects, aberrant functional connectivity of the left DLPFC was found at high working memory load levels only. Compared with healthy controls, pre‐HD individuals exhibited lower connectivity strength in the left putamen, the right anterior cingulate and the left medial prefrontal cortex. Pre‐HD individuals close to the onset of motor symptoms additionally exhibited lower connectivity strength in the right putamen and the left superior frontal cortex. The connectivity strength in the left putamen was associated with several clinical measures including CAG repeat length, Unified Huntington's Disease Rating Scale motor score and predicted years to manifest symptom onset. Conclusion: These findings suggest that early prefrontal connectivity abnormalities in pre‐HD individuals are modulated by cognitive demand.     

Challenges assessing clinical endpoints in early Huntington disease

The basic aim of this study was to evaluate the current accepted standard clinical endpoint for the earliest‐studied HD participants likely to be recruited into clinical trials. As the advent of genetic testing for HD, it is possible to identify gene carriers before the diagnosis of disease, which opens up the possibility of clinical trials of disease‐modifying treatments in clinically asymptomatic persons. Current accepted standard clinical endpoints were examined as part of a multinational, 32‐site, longitudinal, observational study of 786 research participants currently in the HD prodrome (gene‐positive but not clinically diagnosed). Clinical signs and symptoms were used to prospectively predict functional loss as assessed by current accepted standard endpoints over 8 years of follow‐up. Functional capacity measures were not sensitive for HD in the prodrome; over 88% scored at ceiling. Prospective evaluation revealed that the first functional loss was in their accustomed work. In a survival analysis, motor, cognitive, and psychiatric measures were all predictors of job change. To our knowledge, this is the first prospective study ever conducted on the emergence of functional loss secondary to brain disease. We conclude that future clinical trials designed for very early disease will require the development of new and more sensitive measures of real‐life function. © 2010 Movement Disorder Society     

The unified huntington's disease rating scale for advanced patients: Validation and follow‐up study

The Unified Huntington's Disease Rating Scale (UHDRS) adequately measures decline in patients at early and moderate stages of Huntington's disease (HD). In patients with advanced HD, floor effects hamper the evaluation, thus calling for an adjusted scale. We designed the UHDRS‐For Advanced Patients (UHDRS‐FAP) to improve longitudinal assessment of patients at the advanced disease stage. Sixty‐nine patients with a Total Functional Capacity score ≤ 5 were recruited in France and the Netherlands. Among them, 45 patients were followed longitudinally (mean ± standard deviation, 1.6 ± 1.2 years) with the UHDRS‐FAP; 30 patients also were assessed with the UHDRS. In cross‐sectional analyses, the psychometric properties and inter‐rater reliability of the scale were evaluated. Longitudinal analyses were used to evaluate the sensitivity to decline of the UHDRS‐FAP compared with the UHDRS. Internal consistency was higher for motor (0.84) and cognitive (0.91) scores than for somatic (0.70) and behavioral (0.49) scores. Inter‐rater reliability was ≥ 0.88 for all scores. The somatic score, which was specific to the UHDRS‐FAP, declined over time along with motor and cognitive performance on both scales. Although performance with the two scales was correlated, the UHDRS‐FAP appeared to be more sensitive to change and was the only scale that detected decline in patients with a Total Functional Capacity score ≤ 1. Neither scale detected a significant decline in behavioral scores. The results indicate that the UHDRS‐FAP is reliable and more sensitive to change than the original UHDRS for cognitive and motor domains. It offers items that are relevant for daily care. Behavioral scores tended to decline, but this may reflect the decline in patients' communicative abilities. © 2013 International Parkinson and Movement Disorder Society     

Clinical and genetic characteristics in patients with Huntington’s disease from China

Huntington’s disease (HD) is a neurodegenerative disease caused by the expansion of unstable CAG repeats in the HTT gene. There are scarce data about HD in China. Fifty-eight HD patients were consecutively recruited and assessed using the Unified HD Rating Scale (UHDRS) motor section and UHDRS behaviour assessment (UHDRS-b). Genetic analyses were also conducted. Thirty-three women and Twenty -five men were diagnosed with a mean age of 46.1 ± 11.2 years and a mean number of CAG triplet repeats 44.6 ± 4.4. CAG triplet repeat number was negatively correlated with age at onset, and positively correlated with UHDRS-b total score, and its subdomains including depressed mood, low self-esteem, anxiety and irritability. On the other hand, negative correlations were identified between age at onset and UHDRS-b total score, and its subdomains include low self-esteem, anxiety, suicidal thought, irritability and apathy. Disease durations were correlated with UHDRS motor scores and anxiety domain of UHDRS-b. This is the largest series of Chinese HD patients with demographic, clinical and genetic data confirms the demographic features of Chinese HD patients are comparable to those in other ethnic backgrounds. CAG triplet repeat number may also predict the severity of behaviour problems in HD patients besides its predication for age of onset.     

HD‐CAB: A cognitive assessment battery for clinical trials in Huntington's disease1,2,3

Cognitive dysfunction is central to Huntington's disease (HD) and undermines quality of life. Clinical trials are now targeting cognitive outcomes in HD; however, no cognitive battery has been optimized for HD clinical trials. We evaluated 16 cognitive tests in a 20‐site, five‐country, observational study designed to mimic aspects of a clinical trial (e.g., data collection managed by a contract research organization, repeated testing, prespecified statistical analyses). Fifty‐five early HD, 103 premanifest HD (pre‐HD), and 105 controls were tested at visit 1, visit 2 (1‐3 days later), and visit 3 (5‐7 weeks after visit 1). For inclusion in a recommended battery, tests were evaluated for sensitivity, practice effects, reliability, domain coverage, feasibility, and tolerability. Most tests differentiated controls from pre‐HD and early HD and showed excellent psychometric properties. We selected six tests to constitute the Huntington's Disease Cognitive Assessment Battery (HD‐CAB): Symbol Digit Modalities Test, Paced Tapping, One Touch Stockings of Cambridge (abbreviated), Emotion Recognition, Trail Making B, and the Hopkins Verbal Learning Test. These tests demonstrated sensitivity to disease status (Cohen's d effect sizes: early HD= ?1.38 to ?1.90 and pre‐HD= ?0.41 to ?0.78), and acceptable reliability (r's 0.73‐0.93). A composite score yielded large effect sizes (early HD = ?2.44 and pre‐HD = ?0.87) and high reliability (r = 0.95). HD‐CAB is the first cognitive battery designed specifically for use in late premanifest and early HD clinical trials. Adoption of the HD‐CAB will facilitate evaluation of treatments to improve cognition in HD. © 2014 International Parkinson and Movement Disorder Society     

The relationship between CAG repeat length and clinical progression in Huntington's disease

The objective of this study was to examine the relationship between CAG repeat length (CAGn) and clinical progression in patients with Huntington's disease (HD). There are conflicting reports about the relationship between CAGn and clinical progression of HD. We conducted an analysis of data from the Coenzyme Q10 and Remacemide Evaluation in Huntington's Disease (CARE‐HD) clinical trial. We modeled progression over 30 months on the Unified Huntington's Disease Rating Scale (UHDRS) and supplemental neuropsychological and behavioral tests using multiple linear regression. Mean subject age was 47.9 ± 10.5 years and mean CAGn was 45.0 ± 4.1. Multiple linear regression revealed statistically significant associations between CAGn and worsening on several motor, cognitive, and functional outcomes, but not behavioral outcomes. Many effects were clinically important; 10 additional CAG repeats were associated with an 81% increase in progression on the Independence Scale. These associations were not observed in the absence of age adjustment. Age at the time of assessment confounds the association between CAGn and progression. Adjusting for age shows that longer CAGn is associated with greater clinical progression of HD. This finding may account for the variable results from previous studies examining CAGn and progression. Adjusting for CAGn may be important for clinical trials. © 2008 Movement Disorder Society     

A Critical Review of White Matter Changes in Huntington’s Disease

Huntington’s disease is a genetic neurodegenerative disorder. White matter alterations have recently been identified as a relevant pathophysiological feature of Huntington’s disease, but their etiology and role in disease pathogenesis and progression remain unclear. Increasing evidence suggests that white matter changes in this disorder are attributed to alterations in myelin-associated biological processes. This review first discusses evidence from neurochemical studies lending support to the demyelination hypothesis of Huntington’s disease, demonstrating aberrant myelination and changes in oligodendrocytes in the Huntington’s brain. Next, evidence from neuroimaging studies is reviewed, the limitations of the described methodologies are discussed, and suggested interpretations of findings from published studies are challenged. Although our understanding of Huntington’s associated pathological changes in the brain will increasingly rely on neuroimaging techniques, the shortcomings of these methodologies must not be forgotten. Advances in magnetic resonance imaging techniques and tissue modeling will enable a better in vivo, longitudinal characterization of the biological properties of white matter microstructure. This in turn will facilitate identification of disease-related biomarkers and the specification of outcome measures in clinical trials. © 2020 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.     

Cognitive and autonomic dysfunction in presymptomatic and early Huntington’s disease

Huntington’s disease is characterized by disorders of movement, cognition and behavior. Individuals with Huntington’s disease display aberrant changes in the autonomic nervous system that are detected even before the onset of other symptoms. Subtle cognitive dysfunction may start before other clinical manifestations. The aim of the present study was to investigate the autonomic nervous system response to mental arithmetic and the relationship between the autonomic and cognitive/motor function in presymptomatic and early Huntington’s disease. We examined 15 presymptomatic Huntington’s disease gene carriers (PHD), 15 early Huntington’s disease patients (EHD) and 30 healthy controls. PHD and EHD groups were determined according to Unified Huntington’s Disease Rating Scale (UHDRS) motor score. ECG, heart rate, systolic and diastolic blood pressure, and cutaneous laser Doppler flux were measured during rest and during a simple mental arithmetic test. UHDRS cognitive test battery was applied to determine cognitive dysfunction. During mental arithmetic, the heart rate of PHD/EHD increased significantly less than that of controls. Decreased microvascular response to mental arithmetic was found in EHD. Significant correlations for the PHD/EHD group were found between laser Doppler flux response and Symbol Digit Modalities Test score, and between laser Doppler flux response and UHDRS motor score. It seems that central autonomic dysregulation of cardiovascular system in Huntington’s disease goes along with the degeneration of other central neuronal systems. This finding is relevant as it could enable simple and noninvasive testing of disease progression.     

Clinical markers of early disease in persons near onset of Huntington's disease

OBJECTIVE: There is increasing evidence that neuron loss precedes the phenotypic expression of Huntington's disease (HD). As genes for late-onset neurodegenerative diseases are identified, the need for accurate assessment of phenoconversion (i.e., the transition from health to the disease phenotype) will be important. METHODS: Prospective longitudinal evaluation using the Unified Huntington's Disease Rating Scale (UHDRS) was conducted by Huntington Study Group members from 36 sites. There were 260 persons considered "at risk" for HD who initially did not have manifest disease and had at least one subsequent evaluation. Repeat UHDRS data, obtained an average of 2 years later, showed that 70 persons were given a diagnosis of definite HD based on the quantified neurologic examination. RESULTS: Baseline cognitive performances were consistently worse for the at-risk group who demonstrated conversion to a definitive diagnosis compared with those who did not. Longitudinal change scores showed that the at-risk group who did not demonstrate manifest disease during the follow-up study period demonstrated improvements in all cognitive tests, whereas performances in the at-risk group demonstrating conversion to disease during the study declined across cognitive domains. CONCLUSIONS: Neuropsychological measures show impairment 2 years before the development of more manifest motor disease. Findings suggest that these brief cognitive measures administered over time may capture early striatal neural loss in HD.     

Unified Huntington's disease rating scale for advanced patients: Validation and follow‐up study

The Unified Huntington's Disease Rating Scale (UHDRS) adequately measures decline in patients at early and moderate stages of Huntington's disease (HD). In advanced patients, floor effects hamper the evaluation, thus calling for an adjusted scale. We designed the UHDRS‐For Advanced Patients (UHDRS‐FAP), in order to improve longitudinal assessment of patients at advanced disease stage. Sixty‐nine patients with a Total Functional Capacity (TFC) ≤ 5 were recruited in France and in the Netherlands. Among them, 45 patients were followed longitudinally (mean 1.6 ± 1.2 years) with the UHDRS‐FAP; 30 were also assessed with the UHDRS. Cross‐sectional analyses evaluated psychometric properties and interrater reliability of the scale. Longitudinal analyses evaluated the sensitivity to decline compared to the UHDRS. Internal consistency was higher for motor and cognitive scores than for somatic and behavioral scores (0.84, 0.91, 0.70, and 0.49, respectively). Interrater reliability was ≥ 0.88 in all scores. The somatic score, specific to the UHDRS‐FAP, declined over time, as well as motor and cognitive performance with both scales. Although performance with the 2 scales correlated, the UHDRS‐FAP appeared more sensitive to change and was the only scale that detected decline in patients with a TFC ≤ 1. Neither scale detected a significant decline in behavioral scores. The UHDRS‐FAP is reliable and more sensitive to change than the original UHDRS for cognitive and motor domains. It offers items relevant for daily care. Behavioral scores tended to decline but this may reflect the decline in the communicative abilities of the patients. © 2013 International Parkinson and Movement Disorder Society     

Aberrant brain network connectivity in presymptomatic and manifest Huntington's disease: A systematic review

Resting‐state functional magnetic resonance imaging (rs‐fMRI) has the potential to shed light on the pathophysiological mechanisms of Huntington's disease (HD), paving the way to new therapeutic interventions. A systematic literature review was conducted in three online databases according to PRISMA guidelines, using keywords for HD, functional connectivity, and rs‐fMRI. We included studies investigating connectivity in presymptomatic (pre‐HD) and manifest HD gene carriers compared to healthy controls, implementing seed‐based connectivity, independent component analysis, regional property, and graph analysis approaches. Visual network showed reduced connectivity in manifest HD, while network/areas underpinning motor functions were consistently altered in both manifest HD and pre‐HD, showing disease stage‐dependent changes. Cognitive networks underlying executive and attentional functions showed divergent anterior–posterior alterations, possibly reflecting compensatory mechanisms. The involvement of these networks in pre‐HD is still unclear. In conclusion, aberrant connectivity of the sensory‐motor network is observed in the early stage of HD while, as pathology spreads, other networks might be affected, such as the visual and executive/attentional networks. Moreover, sensory‐motor and executive networks exhibit hyper‐ and hypo‐connectivity patterns following different spatiotemporal trajectories. These findings could potentially help to implement future huntingtin‐lowering interventions.     

Clinical correlates of mitochondrial function in Huntington's disease muscle.

Huntington's disease (HD) is caused by an abnormally expanded CAG repeat in the IT-15 gene, which encodes a widely expressed protein called huntingtin. Abnormalities of mitochondrial respiratory chain function, specifically complex II/III, have been identified in HD striatum and defects of energy metabolism have been demonstrated in vivo in skeletal muscle in both symptomatic and presymptomatic HD patients. We have investigated respiratory chain function using histochemical and biochemical methods in HD skeletal muscle from 12 patients and compared these with 12 age and sex-matched controls. The data from the HD patients were related to clinical parameters of HD including the Unified Huntington's Disease Rating Scale (UHDRS). There were positive correlations between CAG repeat years (a product of CAG repeat length and age) and both motor (P < 0.002) and cognitive (P < 0.01) scores of the UHDRS. There was no significant difference in the activities of complexes I to IV compared to age-matched controls. However, there were significant correlations for individual HD complex II/III activities with disease duration (P = 0.017), repeat years (P = 0.032), and cognitive scores (P = 0.019). There was also evidence from ultrastructural studies that inclusion formation may occur in HD muscle. These results provide additional evidence that mutant huntingtin influences mitochondrial complex II/III function in non-neuronal tissue (skeletal muscle) and suggest that muscle may be a potential marker of disease progression in HD.     

Ten‐year rate of longitudinal change in neurocognitive and motor function in prediagnosis Huntington disease

Longitudinal studies of neurocognitive function in prediagnosis Huntington disease (pre‐HD) have been few, and duration of follow‐up has been brief. In this study, 155 individuals at‐risk for HD completed a battery of cognitive and motor tasks at two study visits ～10 years apart. Participants were classified as: (1) at‐risk, without the CAG expansion (healthy controls, NC; n = 112), or (2) CAG expanded (CAG+; n = 43). To examine the rate of decline at different stages of the pre‐HD period, participants in the CAG+ group were further characterized as converters (i.e., individuals who developed manifest HD over the course of the study; n = 21) or nonconverters (n = 22), and their performances were compared. The CAG+ group exhibited faster rates of neurocognitive decline over the course of the study, relative to the NC group. In addition, more rapid decline was associated with closer proximity to estimated age of disease onset in the CAG+ group. Faster rates of motor and psychomotor decline were observed in the CAG+ converter group, relative to the nonconverters. These findings suggest that neurocognitive decline in pre‐HD, particularly in motor and psychomotor domains, begins insidiously and accelerates as individuals approach disease onset. © 2008 Movement Disorder Society     

Rate of functional decline in Huntington's disease. Huntington Study Group

OBJECTIVE: To determine the rate of functional decline in a large cohort of patients with Huntington's disease (HD) followed at 43 sites by the Huntington Study Group (HSG). METHODS: The annual rate of functional decline was measured using the Total Functional Capacity Scale (TFC) and the Independence Scale (IS) in 960 patients with definite HD followed prospectively for a mean of 18.3 months. All patients were rated with the Unified Huntington's Disease Rating Scale (UHDRS). Sample size calculations for hypothetical clinical trials were calculated. Results: A factor analysis of the UHDRS at baseline yielded 15 factors accounting for 77% of the variance. The TFC score declined at a rate of 0.72 units/year (standard error [SE] 0.04) and the IS score declined at a rate of 4.52 units/year (SE 0.23). Lower TFC score at baseline, indicating more severe impairment, was associated with less rapid annual decline in TFC score, perhaps reflecting the floor effect of the scale. The annual rate of decline for 575 patients with baseline TFC scores of 7 to 13 was 0.97 (SE 0.06), was 0.38 (SE 0.08) for 270 patients with baseline TFC scores of 3 to 6, and was 0.06 (SE 0.1) for 101 patients with TFC scores of 0 to 2. In multivariate analysis (n = 960), longer disease duration and better cognitive status at baseline were associated with a less rapid rate of decline in TFC score, whereas depressive symptomatology was the only factor associated with more rapid decline on the IS score. Age at onset of HD, sex, weight, and education did not affect decline on either score. CONCLUSIONS: The comparable rates of decline on the TFC and the IS scores with other published studies suggest that these estimates of functional decline are representative of HD patients who are evaluated at HSG research sites. In longitudinal analysis, longer disease duration and better neuropsychological performance at baseline were associated with a less rapid rate of decline in TFC score, whereas depressive symptomatology at baseline was associated with a more rapid decline in the IS score. These rates of functional decline and the covariates that modify them should be considered in estimating statistical power and designing future therapeutic trials involving HD patients with early or moderately severe disease.     

Whole‐brain atrophy as a measure of progression in premanifest and early Huntington's disease

Therapeutic trials in Huntington's disease (HD) are challenging as clinical progression is slow and variable and reliable biomarkers are lacking. We used magnetic resonance imaging and the brain boundary shift integral to quantify whole‐brain atrophy rates over 1 year in early and premanifest HD subjects, and controls. Early HD subjects had statistically significantly (P = 0.007) increased (threefold higher) rates of whole‐brain atrophy compared with controls. Higher atrophy rates were associated with longer CAG repeat length. MRI‐based measures of whole‐brain atrophy may have potential as a measure of progression in HD. © 2009 Movement Disorder Society