Task-specific training in Huntington disease: a randomized controlled feasibility trial

Clinical Decision Trees to Guide Physical Therapy Management of Persons with Huntington's Disease

BACKGROUND

In 2020, our group published physical therapy clinical practice guidelines (CPG) for people with Huntington's disease (HD). The guideline recommendations were categorized according to six primary movement impairment classifications.

OBJECTIVE

To facilitate implementation of this CPG, we have developed guideline-based algorithms for physical therapy assessments and interventions and recommendations for therapists to overcome barriers to CPG implementation for people with HD.

METHODS

We conducted a literature review of papers that evaluated physical therapy interventions in individuals with HD (n = 26) to identify assessments for each of the primary movement impairment classifications, and then searched for papers (n = 28) that reported their clinometric/psychometric properties in HD. Assessments were evaluated using modified Movement Disorder Society Committee on Rating Scales criteria and other relevant criteria.

RESULTS

We identified a "core set" of physical therapy assessments for persons with HD, including the Six Minute Walk Test, Timed Up and Go Test, Berg Balance Scale, and the Medical Outcomes Study Short Form 36 (SF-36). We then developed guideline-based decision trees to assist in decision making and implementation of the CPG into practice for persons with HD across the continuum of care. Finally, we developed strategies for overcoming barriers to implementation, such as seeking specialized training in HD, engaging caretakers or family members to help the person with HD to exercise, and establishing clinical pathways that support early physical therapy referrals.

CONCLUSION

Knowledge translation documents such as this are essential to promoting implementation of the physical therapy CPGs into clinical practice.

Home-Based Exercise to Improve Motor Functions, Cognitive Functions, and Quality of Life in People with Huntington's Disease: A Systematic Review and Meta-Analysis

Exercise in different settings has become a fundamental part of Huntington's disease (HD) management. The aim of this systematic review and meta-analysis was to investigate the effectiveness of home-based exercises (HBE) in HD. Randomized controlled trials (RCTs) investigating the effect of HBE on motor, cognitive, or health-related quality of life (QoL) outcomes in HD were included. Standardized mean difference (SMD), the 95% confidence interval, and p-values were calculated by comparing the outcomes change between HBE and control groups. Seven RCTs met the inclusion criteria. The included RCTs prescribed different types of HBEs, i.e., aerobic strengthening, walking, balance, and fine motor exercises. The HBE protocol length was between 6 and 36 weeks. The meta-analyses showed a significant effect of HBE intervention on motor function measure by Unified Huntington Disease Rating and overall QoL measure by Short Form-36 post-treatment respectively, [SMD = 0.481, p = 0.048], [SMD = 0.378, p = 0.003]. The pooled analysis did not detect significant changes in cognition, gait characteristics, or functional balance scales. The current study shows the positive effect of HBE in HD, especially on motor function and QoL. No significant adverse events were reported. The current results support the clinical effect of HBE intervention on motor function and QoL in HD patients. However, these results should be taken with caution due to the limited available evidence. Well-designed clinical studies that consider the disease severity and stages are required in the future.

Effects of Exercise on Skeletal Muscle Pathophysiology in Huntington's Disease

Huntington's disease (HD) is a rare, hereditary, and progressive neurodegenerative disease, characterized by involuntary choreatic movements with cognitive and behavioral disturbances. In order to mitigate impairments in motor function, physical exercise was integrated in HD rehabilitative interventions, showing to be a powerful tool to ameliorate the quality of life of HD-affected patients. This review aims to describe the effects of physical exercise on HD-related skeletal muscle disorders in both murine and human models. We performed a literature search using PubMed, Scopus, and Web of Science databases on the role of physical activity in mouse models of HD and human patients. Fifteen publications fulfilled the criteria and were included in the review. Studies performed on mouse models showed a controversial role played by exercise, whereas in HD-affected patients, physical activity appeared to have positive effects on gait, motor function, UHDMRS scale, cognitive function, quality of life, postural stability, total body mass, fatty acid oxidative capacity, and VO2 max. Physical activity seems to be feasible, safe, and effective for HD patients. However, further studies with longer follow-up and larger cohorts of patients will be needed to draw firm conclusions on the positive effects of exercise for HD patients.

New Avenues for the Treatment of Huntington's Disease

Huntington’s disease (HD) is a neurodegenerative disorder caused by a CAG expansion in the HD gene. The disease is characterized by neurodegeneration, particularly in the striatum and cortex. The first symptoms usually appear in mid-life and include cognitive deficits and motor disturbances that progress over time. Despite being a genetic disorder with a known cause, several mechanisms are thought to contribute to neurodegeneration in HD, and numerous pre-clinical and clinical studies have been conducted and are currently underway to test the efficacy of therapeutic approaches targeting some of these mechanisms with varying degrees of success. Although current clinical trials may lead to the identification or refinement of treatments that are likely to improve the quality of life of those living with HD, major efforts continue to be invested at the pre-clinical level, with numerous studies testing novel approaches that show promise as disease-modifying strategies. This review offers a detailed overview of the currently approved treatment options for HD and the clinical trials for this neurodegenerative disorder that are underway and concludes by discussing potential disease-modifying treatments that have shown promise in pre-clinical studies, including increasing neurotropic support, modulating autophagy, epigenetic and genetic manipulations, and the use of nanocarriers and stem cells.

Approach to Posture and Gait in Huntington's Disease

Disturbances of gait occur in all stages of Huntington’s disease (HD) including the premanifest and prodromal stages. Individuals with HD demonstrate the slower speed of gait, shorter stride length, and increased variability of gait parameters as compared to controls; cognitive disturbances in HD often compound these differences. Abnormalities of gait and recurrent falls lead to decreased quality of life for individuals with HD throughout the disease. This scoping review aims to outline the cross-disciplinary approach to gait evaluation in HD and will highlight the utility of objective measures in defining gait abnormalities in this patient population.

Physical exercise improves quality of life, depressive symptoms, and cognition across chronic brain disorders: a transdiagnostic systematic review and meta-analysis of randomized controlled trials

We performed a meta-analysis to synthesize evidence on the efficacy and safety of physical exercise as an add-on therapeutic intervention for quality of life (QoL), depressive symptoms and cognition across six chronic brain disorders: Alzheimer's disease, Huntington's disease, multiple sclerosis, Parkinson's disease, schizophrenia and unipolar depression. 122 studies ( = k) (n = 7231) were included. Exercise was superior to treatment as usual in improving QoL (k = 64, n = 4334, ES = 0.40, p < 0.0001), depressive symptoms (k = 60, n = 2909, ES = 0.78, p < 0.0001), the cognitive domains attention and working memory (k = 21, n = 1313, ES = 0.24, p < 0.009), executive functioning (k = 14, n = 977, ES = 0.15, p = 0.013), memory (k = 12, n = 994, ES = 0.12, p = 0.038) and psychomotor speed (k = 16, n = 896, ES = 0.23, p = 0.003). Meta-regression showed a dose-response effect for exercise time (min/week) on depressive symptoms (β = 0.007, p = 0.012). 69% of the studies that reported on safety, found no complications. Exercise is an efficacious and safe add-on therapeutic intervention showing a medium-sized effect on QoL and a large effect on mood in patients with chronic brain disorders, with a positive dose-response correlation. Exercise also improved several cognitive domains with small but significant effects.

Biological Motion Perception in Huntington's Disease

BACKGROUND

The ability of healthy individuals to detect biological motion by using a small number of moving points is well established in animals and humans. Perception of human movements may depend on internal models that drive self-generated movements and influence motion discrimination (Reed CL et al. 1995 and 2007). As a person's motor repertoire deteriorates, the accuracy of these models may also decrease.

OBJECTIVE

Determine if people with symptomatic Huntington's disease (HD) have difficulty perceiving movements.

METHODS

In this study point-light displays were created with a Vicon Motion Capture System by recording one individual with (impaired) and one individual without (healthy) Parkinson's disease using a 13 joint marker set. Participants were asked to distinguish between three movements and determine if the movement was impaired or healthy. The ability of participants with and without HD to distinguish movement patterns and the time to perception were recorded.

RESULTS

Analyses found participants with HD had a decreased ability to correctly detect movements and point-light image type. The stair climbing motion showed the largest effect as participants with HD had more difficulty correctly identifying both the movement and whether it was impaired or healthy. In addition, the participants without HD showed an improvement as trials progressed which could not be observed in the HD cohort.

CONCLUSIONS

As people with symptomatic HD have difficulty perceiving movements further investigations using point-light displays should be done to determine if these impairments might serve as an easily administered, non-invasive marker of disease state.

Huntington's Disease Clinical Trials Corner: January 2019

In this edition of the Huntington's Disease Clinical Trials Corner we expand on the GENERATION-HD1 and PACE-HD trials, and we list all currently registered and ongoing clinical trials in Huntington's disease.

Clinical recommendations to guide physical therapy practice for Huntington disease

OBJECTIVE

In the past decade, an increasing number of studies have examined the efficacy of physical therapy interventions in people with Huntington disease (HD).

METHODS

We performed a mixed-methods systematic review using Joanna Briggs Institute (JBI) methodology and included experimental and observational study designs. The search resulted in 23 quantitative studies and 3 qualitative studies from which we extracted data using JBI standardized extraction tools. Results of this review suggested that physical therapy interventions may improve motor impairments and activity limitations in people with HD. Here, we expand on the review findings to provide specific recommendations to guide clinical practice.

RESULTS

We recommend the following specific physical therapy interventions for people with HD: aerobic exercise (grade A evidence), alone or in combination with resistance training to improve fitness and motor function, and supervised gait training (grade A evidence) to improve spatiotemporal features of gait. In addition, there is weak (grade B) evidence that exercise training improves balance but does not show a reduction in the frequency of falls; inspiratory and expiratory training improves breathing function and capacity; and training of transfers, getting up from the floor, and providing strategies to caregivers for involvement in physical activity in the midstages of HD may improve performance. There is expert consensus for the use of positioning devices, seating adaptations, and caregiver training in late stages of HD.

CONCLUSIONS

There is strong evidence to support physical therapy interventions to improve fitness, motor function, and gait in persons with HD.

Exercise as a prescription for patients with various diseases

A growing understanding of the benefits of exercise over the past few decades has prompted researchers to take an interest in the possibilities of exercise therapy. Because each sport has its own set of characteristics and physiological complications that tend to occur during exercise training, the effects and underlying mechanisms of exercise remain unclear. Thus, the first step in probing the effects of exercise on different diseases is the selection of an optimal exercise protocol. This review summarizes the latest exercise prescription treatments for 26 different diseases: musculoskeletal system diseases (low back pain, tendon injury, osteoporosis, osteoarthritis, and hip fracture), metabolic system diseases (obesity, type 2 diabetes, type 1 diabetes, and nonalcoholic fatty liver disease), cardio-cerebral vascular system diseases (coronary artery disease, stroke, and chronic heart failure), nervous system diseases (Parkinson's disease, Huntington's disease, Alzheimer's disease, depression, and anxiety disorders), respiratory system diseases (chronic obstructive pulmonary disease, interstitial lung disease, and after lung transplantation), urinary system diseases (chronic kidney disease and after kidney transplantation), and cancers (breast cancer, colon cancer, prostate cancer, and lung cancer). Each exercise prescription is displayed in a corresponding table. The recommended type, intensity, and frequency of exercise prescriptions are summarized, and the effects of exercise therapy on the prevention and rehabilitation of different diseases are discussed.

Physical Activity and Exercise Outcomes in Huntington Disease (PACE-HD): Protocol for a 12-Month Trial Within Cohort Evaluation of a Physical Activity Intervention in People With Huntington Disease

BACKGROUND

Exercise is emerging as an important aspect in the management of disease-related symptoms and functional decline in people with Huntington disease (HD). Long-term evaluation of physical activity and exercise participation in HD has yet to be undertaken.

OBJECTIVE

The objective is to investigate the feasibility of a nested randomized controlled trial (RCT) alongside a longitudinal observational study of physical activity and exercise outcomes in people with HD.

DESIGN

This will be a 12-month longitudinal observational study (n = 120) with a nested evaluation of a physical activity intervention (n = 30) compared with usual activity (n = 30) using a "trial within a cohort" design.

SETTING

The study will take place in HD specialist clinics in Germany, Spain, and the United States, with intervention delivery in community settings.

PARTICIPANTS

The participants will have early-mid-stage HD and be participating in the Enroll-HD study.

INTERVENTION

This will be a 12-month physical activity behavioral change intervention, delivered by physical therapists in 18 sessions, targeting uptake of aerobic exercise and increased physical activity.

MEASUREMENTS

All participants (n = 120) will complete Enroll-HD assessments (motor, cognitive, behavioral, and quality of life) at baseline and at 12 months. Additional Physical ACtivity and Exercise Outcomes in Huntington Disease (PACE-HD) assessments include fitness (predicted maximal oxygen uptake [V  o2max]), self-reported and quantitative measures of physical activity, disease-specific symptoms, and walking endurance. RCT participants (n = 60) will complete an additional battery of quantitative motor assessments and a 6-month interim assessment. Enroll-HD data will be linked to PACE-HD physical activity and fitness data.

LIMITATIONS

The limitations include that the embedded RCT is open, and assessors at RCT sites are not blinded to participant allocation.

CONCLUSION

PACE-HD will enable determination of the feasibility of long-term physical activity interventions in people with HD. The novel "trial within a cohort" design and incorporation of data linkage have potential to reduce participant burden. This design could be applied to other neurological diseases and movement disorders where recruitment and retention are challenging.

Exercise Interventions in Huntington's Disease: An Individual Patient Data Meta-Analysis

Background

Physical activity may be beneficial in Huntington's disease (HD); however, studies to date have been underpowered to detect change. We combined data from five randomized controlled feasibility trials using individual patient data meta-analyses.

Methods/Design

All trial interventions comprised a combination of supervised and self-directed physical activity, with varied emphasis on aerobic, strength, endurance, flexibility, and task training. Duration ranged from 8 to 16 weeks. The primary outcome was the modified Unified Huntington's Disease Rating Motor Score. Secondary outcomes included the Symbol Digit Modality Test, Berg Balance Scale, 30-second Chair stand, Timed Up and Go, Gait Speed, Physical Performance Test, Six-Minute Walk, International Physical Activity Questionnaire, Hospital Anxiety and Depression Scale, EuroQol Health Utility Index, and Short-Form 36 Health Related Quality of Life Scale. The primary analysis utilized a two-stage approach. A one-stage approach was explored as a sensitivity analysis using a cross-classified (by study site) linear mixed-effects model.

Results

One hundred twenty-one participants provided complete data. Risk of bias was moderate; however, primary outcomes were blind assessed. Primary pooled effect estimates adjusted for baseline modified motor score (95% confidence interval) were 0.2 (-2.1 to 2.6) favoring control. There was considerable heterogeneity between the studies.

Conclusions

There was no evidence of an exercise effect on the modified motor score in these relatively short-duration interventions. Longer-duration trials incorporating supervised components meeting frequency, intensity, time, and type principles are required. Lack of common outcomes limited the analysis and highlight the importance of a core outcome set for evaluating exercise in HD.

International Guidelines for the Treatment of Huntington's Disease

The European Huntington's Disease Network (EHDN) commissioned an international task force to provide global evidence-based recommendations for everyday clinical practice for treatment of Huntington's disease (HD). The objectives of such guidelines are to standardize pharmacological, surgical and non-pharmacological treatment regimen and improve care and quality of life of patients. A formalized consensus method, adapted from the French Health Authority recommendations was used. First, national committees (French and English Experts) reviewed all studies published between 1965 and 2015 included dealing with HD symptoms classified in motor, cognitive, psychiatric, and somatic categories. Quality grades were attributed to these studies based on levels of scientific evidence. Provisional recommendations were formulated based on the strength and the accumulation of scientific evidence available. When evidence was not available, recommendations were framed based on professional agreement. A European Steering committee supervised the writing of the final recommendations through a consensus process involving two rounds of online questionnaire completion with international multidisciplinary HD health professionals. Patients' associations were invited to review the guidelines including the HD symptoms. Two hundred and nineteen statements were retained in the final guidelines. We suggest to use this adapted method associating evidence base-medicine and expert consensus to other rare diseases.

Exercise in Huntington's Disease: Current State and Clinical Significance

Background

Huntington's disease (HD) is a rare, progressive neurodegenerative disease. Currently, there is no cure for the disease, but treatment may alleviate HD symptoms. In recent years, several exercise training interventions have been conducted in HD patients. In the current article, we review previous studies investigating targeted exercise training interventions in HD patients.

Methods

We performed a literature search using the PubMed, Scopus, Web of Science, and Google Scholar databases on exercise training interventions in HD patients. Six publications fulfilled the criteria and were included in the review.

Results

Exercise training resulted in beneficial effects on cardiovascular and mitochondrial function. Training effects on cognition, motor function, and body composition were less congruent, but a positive effect seems likely. Health-related quality of life during the training interventions was stable. Most studies reported no related adverse events in response to training.

Discussion

Exercise training seems to be safe and feasible in HD patients. However, current knowledge is mainly based on short, small-scale studies and it cannot be transferred to all HD patients. Therefore, longer-term interventions with larger HD patient cohorts are necessary to draw firm conclusions about the potentially positive effects of exercise training in HD patients.

Effects of multidisciplinary therapy on physical function in Huntington's disease

OBJECTIVE

The primary objective of this trial was to evaluate the effects of outpatient multidisciplinary therapy, compared to usual care, on measures of physical function and muscle strength in patients with manifest Huntington's disease (HD).

METHODS

Twenty-two patients with clinically verified HD were randomized to receive 36 weeks of outpatient multidisciplinary therapy or usual care. Outpatient multidisciplinary therapy comprised 9 months of supervised exercise, cognitive therapy and self-directed home-based exercise. Usual care consisted of standard medical care. Patients were assessed at 0 and 36 weeks by blinded assessors. The primary outcome was changed in mobility as measured by the 10-m Timed Walk Test. Secondary outcome measures included changes in manual dexterity (Timed Nut and Bolt Test), balance (Berg Balance Scale), cardiorespiratory endurance (6-Minute Walk Test) and upper and lower extremity muscle strength (isokinetic and isometric muscle strength and 10 Repetition Sit-to-Stand Tests).

RESULTS

Patients receiving outpatient multidisciplinary therapy demonstrated significantly enhanced manual dexterity (P < 0.05) and lower extremity muscle strength (P < 0.05) than patients receiving usual care. No significant differences in mobility, balance, cardiorespiratory endurance and upper extremity strength outcomes were observed between groups after the intervention period. There were no adverse events associated with multidisciplinary therapy.

CONCLUSION

Our findings suggest that outpatient multidisciplinary therapy has positive effects on manual dexterity and muscle strength, but no meaningful effects on mobility, balance, cardiorespiratory endurance and upper extremity muscle strength in patients with HD. Larger randomized controlled trials are needed to confirm these preliminary findings.

Treadmill training may be an effective form of task-specific training for improving mobility in people with Parkinson's disease and multiple sclerosis: a systematic review and meta-analysis

BACKGROUND

Task-specific training is an effective form of rehabilitation for improving mobility in neurological conditions. However, it remains unclear if task-specific training is effective in people with progressive disease.

OBJECTIVE

To establish the efficacy of task-specific training on the mobility of individuals with progressive neurological conditions.

DATA SOURCES

Electronic databases MEDLINE, EMBASE, CINAHL and Cochrane Database of Systematic Reviews.

STUDY ELIGIBILITY CRITERIA

Randomised controlled trials investigating the effect of task-specific training on mobility and falls rate in individuals with progressive neurological conditions.

STUDY APPRAISAL/SYNTHESIS METHODS

Risk of bias of individual studies was assessed using the Physiotherapy Evidence Database (PEDro) Scale. Mean differences (MD) and 95% confidence intervals were calculated and combined in meta-analysis.

RESULTS

Analysis of 16 trials found treadmill training improved comfortable walking velocity (m/second) in people with Parkinson's disease (MD 0.21m/second, 95%CI 0.15 to 0.27) and multiple sclerosis (MD 0.36m/second, 95%CI 0.20 to 0.52). Treadmill training improved stride length (m) (MD 0.12m, 95%CI 0.02 to 0.23) and step length (m) (MD 0.12m, 95%CI 0.01 to 0.23) in people with Parkinson's disease and walking endurance in people with multiple sclerosis (MD 26.53m, 95%CI 12.23 to 40.84). Treadmill training had no effect on cadence and did not improve walking endurance in Parkinson's disease. Over-ground walking did not improve mobility in Parkinson's disease or multiple sclerosis.

LIMITATIONS

Study sample sizes were small and findings must be interpreted with caution.

CONCLUSION

Treadmill training may be effective for improving mobility in people with Parkinson's disease and multiple sclerosis. The effectiveness of over-ground walking is uncertain.

SYSTEMATIC REVIEW PROSPERO REGISTRATION NUMBER

CRD42016047334.

A Classification System to Guide Physical Therapy Management in Huntington Disease: A Case Series

BACKGROUND AND PURPOSE

Individuals with Huntington disease (HD), a rare neurological disease, experience impairments in mobility and cognition throughout their disease course. The Medical Research Council framework provides a schema that can be applied to the development and evaluation of complex interventions, such as those provided by physical therapists. Treatment-based classifications, based on expert consensus and available literature, are helpful in guiding physical therapy management across the stages of HD. Such classifications also contribute to the development and further evaluation of well-defined complex interventions in this highly variable and complex neurodegenerative disease. The purpose of this case series was to illustrate the use of these classifications in the management of 2 individuals with late-stage HD.

CASE DESCRIPTION

Two females, 40 and 55 years of age, with late-stage HD participated in this case series. Both experienced progressive declines in ambulatory function and balance as well as falls or fear of falling. Both individuals received daily care in the home for activities of daily living.

INTERVENTION

Physical therapy Treatment-Based Classifications for HD guided the interventions and outcomes. Eight weeks of in-home balance training, strength training, task-specific practice of functional activities including transfers and walking tasks, and family/carer education were provided.

OUTCOMES

Both individuals demonstrated improvements that met or exceeded the established minimal detectible change values for gait speed and Timed Up and Go performance. Both also demonstrated improvements on Berg Balance Scale and Physical Performance Test performance, with 1 of the 2 individuals exceeding the established minimal detectible changes for both tests. Reductions in fall risk were evident in both cases.

DISCUSSION

These cases provide proof-of-principle to support use of treatment-based classifications for physical therapy management in individuals with HD. Traditional classification of early-, mid-, and late-stage disease progression may not reflect patients' true capabilities; those with late-stage HD may be as responsive to interventions as those at an earlier disease stage.Video Abstract available for additional insights from the authors (see Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A172).

Physical Therapy and Exercise Interventions in Huntington's Disease: A Mixed Methods Systematic Review

Background:

A number of studies evaluating physical therapy and exercise interventions in Huntington’s disease have been conducted over the past 15 years. However, an assessment of the quality and strength of the evidence in support of these interventions is lacking.

Objective:

The purpose of this systematic review was to investigate the effectiveness of physical therapy and exercise interventions in people with Huntington’s disease, and to examine the perceptions of patients, families and caregivers of these interventions.

Methods:

This mixed-methods systematic review utilized the Joanna Briggs Institute (JBI) approach and extraction tools to evaluate the literature from January 2003 until May 2016. The review considered interventions that included exercise and physical therapy interventions, and included both quantitative and qualitative outcome measures.

Results:

Twenty (20) studies met the inclusion criteria, including eighteen (18) that had quantitative outcome measures and two (2) that utilized qualitative methods. JBI Levels of evidence for the 18 quantitative studies were as follows: Eight studies were at evidence Level 1, seven were at Level 2, two were at Level 3, and one was at Level 4.

Conclusions:

Our review suggests that there is preliminary support for the benefits of exercise and physical activity in Huntington’s disease in terms of motor function, gait speed, and balance, as well as a range of physical and social benefits identified through patient-reported outcomes. Variability in mode of intervention as well as outcome measures limits the interpretability of these studies, and high-quality studies that incorporate adaptive trial designs for this rare disease are needed.

Rating Scales and Performance-based Measures for Assessment of Functional Ability in Huntington's Disease: Critique and Recommendations

Limitation of functional ability is a major feature of Huntington's disease (HD). The International Parkinson and Movement Disorder Society (MDS) commissioned the appraisal of the use and clinimetric properties of clinical measures of functional ability that have been applied in HD studies and trials to date, to make recommendations regarding their use based on standardized criteria. After a systematic literature search, we included a total of 29 clinical measures grouped into two categories: (1) performance-based measures (e.g., balance, walking, and reaching/grasping), and (2) rating scales. Three performance-based measures are rated as "recommended": the Tinetti Mobility Test for screening of fall risk and for severity assessment of mobility in patients with manifest HD (up to stage III); the Berg Balance Scale for severity of balance impairment; and the Six-Minute Walk Test for assessment of walking endurance (severity) in HD subjects with preserved ambulation. No rating scale targeting functional ability reached a "recommended" status either for screening or severity measurement. The main challenges identified in this review include applying widely accepted conceptual frameworks to the identified measures, the lack of validation of clinical measures to detect change over time, and absence of validated measures for upper limb function. Furthermore, measures of capacity or ability to perform activities of daily living had ceiling effects in people with early and pre-manifest HD. We recommend that the MDS prioritize the development of new scales that capture small, but meaningful changes in function over time for outcome assessment in clinical trials, particularly in earlier stages of HD.

Quality of Life in Huntington's Disease: Critique and Recommendations for Measures Assessing Patient Health-Related Quality of Life and Caregiver Quality of Life

The compromise of quality of life in Huntington's disease is a major issue, both for individuals with the disease as well as for their caregivers. The International Parkinson and Movement Disorder Society commissioned a review of the use and clinimetric validation status of measures used in Huntington's disease to assess aspects related with quality of life and to make recommendations on their use following standardized criteria. We included both patient-centered measures (patient health-related quality-of-life measures) and caregiver-centered measures (caregiver quality-of-life measures). After conducting a systematic literature search, we included 12 measures of patient health-related quality of life and 2 measures of caregiver quality of life. Regarding patient-centered measures, the Medical Outcomes Study 36-Item Short-Form Health Survey is "recommended" as a generic assessment of health-related quality of life in patients with Huntington's disease. The 12-Item Short Form Health Survey, the Sickness Impact Profile, the 12-item World Health Organization Disability Assessment Schedule, and the Huntington's Disease Health-Related Quality of Life questionnaire are "suggested." No caregiver-centered quality-of-life measure obtained a "recommended" status. The Alzheimer's Carer's Quality of Life Inventory and the Huntington's Disease Quality of Life Battery for Carers are "suggested." Recognizing that the assessment of patient health-related quality of life can be challenging in Huntington's disease, as patients may lack insight and there is insufficient clinimetric testing of these scales, the committee concluded that further validation of currently available health-related quality-of-life measures should be undertaken, namely, those Huntington's disease-specific health-related quality-of-life measures that have recently been reported and used. © 2018 International Parkinson and Movement Disorder Society.

Gait, balance, and falls in Huntington disease

Huntington disease (HD) is an autosomal-dominant, progressive, neurodegenerative disorder, characterized by involuntary movements and other motor impairments, cognitive/behavioral symptoms, and psychiatric disorders. Gait and balance impairments and falls greatly impact on the quality of life among people with HD, and being fall-prone is one of the strongest predictors of nursing-home placement. Gait impairment in HD is characterized by bradykinesia, reduced velocity, and increased variability in spatiotemporal features. Detrimental changes in symmetry, step length, stride time, balance measures, gait adaptability (external cues, dual tasking), and hypo/hyperkinesia have also been observed. Balance impairment is characterized by impairments of anticipatory balance without a change in base of support, anticipatory balance with a change in base of support, and reactive balance. In addition to gait and balance impairment, people with HD have a range of intrinsic and extrinsic factors that increase fall risk, including reduced cognitive reserve for dual tasking. Currently there is some evidence to suggest exercise interventions can address some HD-specific gait and balance deficits. However, no intervention studies to date have specifically targeted falls. Large, well-designed, randomized controlled trials are needed to guide future fall prevention interventions in people with HD.

A pilot study of a minimally supervised home exercise and walking program for people with Parkinson's disease in Jordan

Aim: This study aimed to evaluate the feasibility and cultural considerations of a minimally supervised, home-based exercise program in Jordan. Methods: Quantitative and qualitative approaches were used. Thirty participants were randomly allocated to either an 8-week intervention group (n = 16), or a standard care group (n = 14). The intervention incorporated the home use of an exercise DVD, walking program and initial instructional sessions and weekly phone calls provided by a physiotherapist. Interviews were used to explore feasibility. Unified Parkinson's disease rating scale (UPDRS-III); balance and walking speed were assessed. Results: The retention rate was 86.7% and mean adherence rate was 77%. Personal and sociocultural barriers of adherence to the exercise program were identified. UPDRS-III at follow-up was lower in the intervention group. Conclusion: A home exercise program was feasible. Sociocultural barriers specific to Arabic culture may affect the uptake of such an intervention in Parkinson's disease in these countries.

The role of rehabilitation therapy in Huntington disease

The role of rehabilitation interventions is increasingly considered a key component to effective management of people with Huntington disease (HD). Lifestyle factors, such as activity level and exercise, as well as specific motor training may be helpful in managing the functional sequelae of HD and possibly slowing disease progression. In this chapter, we focus on the role of rehabilitation therapy in secondary and tertiary prevention of the potentially devastating consequences of HD. We provide a brief overview of the range of motor and cognitive impairments in HD and their effect on functional abilities. We further discuss emerging evidence in terms of the role of exercise, physical activity, and physical therapies in helping to minimize functional loss and maximize quality of life throughout the disease process. Future directions with respect to intensive and goal-directed exercise, including aerobic and strengthening programs, are also discussed. This is an area of particular importance alongside exploring the potential that motor-training paradigms have in mediating the effects of disease-modifying drugs, cell replacement therapy, or genetic manipulations, when available.

A randomized, controlled trial of a multi-modal exercise intervention in Huntington's disease

INTRODUCTION

This study aimed to evaluate the feasibility and benefit of a structured exercise intervention in people with Huntington's Disease (HD).

METHODS

This study was conducted at 6 sites, and participants were randomized into either exercise or control (usual care) groups, and were assessed at baseline, 13 and 26 weeks. The intervention was a 12 week, three times per week progressive exercise program, including aerobic (stationary cycling) and upper and lower body strengthening exercise with tapered 1:1 support for 20 of 36 sessions.

RESULTS

314 adults were assessed for eligibility: 248 did not meet inclusion criteria, 34 declined, and 32 were recruited and randomized. Three individuals in the intervention group were withdrawn within the first month due to concomitant medical conditions, resulting in 14 participants in intervention and 15 in control groups. There were two AEs in the intervention group, both related to previous medical conditions, and there were two SAEs, both in the control group. The intervention group had better fitness (predicted VO₂ max difference: 492.3 ml min^-1, 95% CI: [97.1, 887.6]), lower UHDRS mMS (difference 2.9 points, 95% [-5.42, -0.32]) and lower weight at Week 13 (difference 2.25 kg, 95% CI: [-4.47, -0.03]).

CONCLUSION

This study demonstrates that a short-term exercise intervention is safe and feasible. Individuals with HD may benefit from structured exercise, and intensity, monitoring and support may be key factors in optimizing response. Larger scale trials are now required to fully elucidate the extended clinical potential of exercise in HD.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN11392629.

Clinical diagnosis and management in early Huntington's disease: a review

This review focuses on clinical diagnosis and both pharmacological and nonpharmacological therapeutic options in early stages of the autosomal dominant inherited neurodegenerative Huntington's disease (HD). The available literature has been reviewed for motor, cognitive, and psychiatric alterations, which are the three major symptom domains of this devastating progressive disease. From a clinical point of view, one has to be aware that the HD phenotype can vary highly across individuals and during the course of the disease. Also, symptoms in juvenile HD can differ substantially from those with adult-onset of HD. Although there is no cure of HD and management is limited, motor and psychiatric symptoms often respond to pharmacotherapy, and nonpharmacological approaches as well as supportive care are essential. International treatment recommendations based on study results, critical statements, and expert opinions have been included. This review is restricted to symptomatic and supportive approaches since all attempts to establish a cure for the disease or modifying therapies have failed so far.