Huntington Study Group's Neuropsychology Working Group: Implementing Non-Motor Diagnostic Criteria.

Background: The clinical diagnosis of manifest Huntington's disease (HD) relies on a high level of clinical confidence (99% confidence) of HD-consistent motor signs. Longitudinal data have reliably identified cognitive and behavioral dysfunction predating clinical motor diagnosis by up to 15 years. Reliance on motor signs to establish a diagnosis of HD increases risk of early misdiagnosis or delayed diagnosis. Clinical neuropsychologists are uniquely positioned to advise on the clinical application of the Movement Disorder Society Task Force's recently proposed non-motor diagnostic criteria for HD. Objectives: To provide (1) a recommended clinical approach toward non-motor diagnostic criteria in persons with HD and facilitation of accurate diagnosis; (2) recommended practices for medical treatment providers to screen and longitudinally monitor non-motor signs of HD. Methods: The Huntington Study Group re-established the Neuropsychology Working Group, then recruited a multi-disciplinary group of neuropsychologists, neurologists, and psychiatrists to conduct an unstructured literature review and discuss expert opinions on practice, to facilitate an informal consensus opinion to accomplish the objectives. Results: The opinion and an example protocol for medical treatment providers to screen, monitor, and triage non-motor signs and symptoms of Huntington's disease is provided. Conclusions: Clinical diagnosis of non-motor HD is empirically justified and clinically important. Screening and triage by non-neuropsychologist clinicians can aid in detecting and monitoring non-motor Huntington's disease manifestation. The Neuropsychology Working Group consensus advances good clinical practice, clinical research, and quality of life. A companion position paper presenting the details of our consensus opinion regarding evidence-based guidelines for neuropsychological practice is forthcoming.

Huntington study group's neuropsychology working group position on best practice recommendations for the clinical neuropsychological evaluation of patients with Huntington disease.

Objective: Neuropsychological evaluation is critical to detection and management of cognitive and neuropsychiatric changes associated with Huntington disease (HD). Accurate assessment of non-motor complications of HD is critical given the prominent impact on functional disability, frequently commensurate with or exceeding that of motor symptoms. The increasing emphasis on developing disease-modifying therapies targeting cognitive decline in HD requires consensus on clinical neuropsychological assessment methods. The Neuropsychology Working Group (NPWG) of the Huntington Study Group (HSG) sought to provide evidence and consensus-based, practical guidelines for the evaluation of cognitive and neuropsychiatric symptoms associated with HD. Method: The NPWG recruited a multi-disciplinary group of neuropsychologists, neurologists, and psychiatrists to inform best practices in assessing, diagnosing, and treating the non-motor symptoms in HD. A review was circulated among the NPWG, and in an iterative process informed by reviewed literature, best practices in neuropsychological evaluation of patients with HD were identified. Results: A brief review of the available literature and rational for a clinical consensus battery is offered. Conclusion: Clinical neuropsychologists are uniquely positioned to both detect and characterize the non-motor symptoms in HD, and further, provide neurologists and allied health professions with clinically meaningful information that impacts functional outcomes and quality of life. The NPWG provides guidance on best practices to clinical neuropsychologists in this statement. A companion paper operationalizing clinical application of previous research-based non-motor diagnostic criteria for HD is forthcoming, which also advises on non-motor symptom screening methods for the non-neuropsychologist working with HD.

The Safety of Deutetrabenazine for Chorea in Huntington Disease: An Open-Label Extension Study.

BACKGROUND: Deutetrabenazine is approved in the USA, China, Australia, Israel, Brazil, and South Korea for the treatment of chorea associated with Huntington disease. OBJECTIVE: We aimed to evaluate the long-term safety and tolerability of deutetrabenazine for the treatment of Huntington disease. METHODS: This open-label, single-arm, multi-center study included patients who completed a double-blind study (Rollover) and patients who converted overnight from a stable tetrabenazine dose (Switch). Exposure-adjusted incidence rates (adverse events per person-year) were calculated. Efficacy was analyzed using a stable post-titration timepoint (8 weeks). Changes in the Unified Huntington's Disease Rating Scale total motor score and total maximal chorea score from baseline to week 8, as well as those from week 8 to week 145 (or the last visit on the study drug if that occurred earlier), were evaluated as both efficacy and safety endpoints during the study. RESULTS: Of 119 patients (Rollover, n = 82; Switch, n = 37), 100 (84%) completed ≥ 1 year of treatment. End-of-study exposure-adjusted incidence rates for adverse events in Rollover and Switch, respectively, were: any, 2.57 and 4.02; serious, 0.11 and 0.14; leading to dose suspension, 0.05 and 0.04. Common adverse events (≥ 4% either cohort) included somnolence (Rollover, 20%; Switch, 30%), depression (32%; 22%), anxiety (27%; 35%), insomnia (23%; 16%), and akathisia (6%; 11%). Adverse events of interest included suicidality (9%; 5%) and parkinsonism (4%; 8%). Mean dose at week 8 was 38.1 mg (Rollover) and 36.5 mg (Switch). Mean dose across cohorts after titration was 37.6 mg; at the final visit, mean dose across cohorts was 45.7 mg. Patients showed minimal change in the Unified Huntington's Disease Rating Scale total maximal chorea scores with stable dosing from weeks 8-145 or at the end of treatment, but total motor score increased versus week 8 (mean change [standard deviation]: 8.2 [11.9]). There were no unexpected adverse events upon drug withdrawal, and mean (standard deviation) total maximal chorea scores increased 4.7 (4.6) units from week 8 to 1-week follow-up. CONCLUSIONS: Adverse events observed with long-term deutetrabenazine exposure were consistent with previous studies. Reductions in chorea persisted over time. Upon treatment cessation, there was no unexpected worsening of chorea. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01897896.

Contemporary health care for Huntington disease.

Providing medical care for people and families affected by Huntington disease (HD) can be a rewarding effort when realistic goals of improved quality of life and optimized functional status are set. Multiple disease symptoms can remit or improve with currently available pharmacologic and behavioral interventions, even though barriers exist that interfere with access to treatment. Connecting expert multidisciplinary teams with community-based care, developing treatment guidelines, and involving the HD family community in quality improvements can achieve an integrated system of health care delivery. Engaging people with HD in high-quality compassionate care will not only improve lives, it will also encourage participation in clinical trials that search for disease-modifying treatments that will reduce or bring the suffering of HD to an end.

Effect of Deutetrabenazine on Chorea Among Patients With Huntington Disease: A Randomized Clinical Trial.

IMPORTANCE: 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. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01795859.

Caregiver burden in atypical dementias: comparing frontotemporal dementia, Creutzfeldt-Jakob disease, and Alzheimer's disease.

BACKGROUND: Caregiver burden is a significant issue in the treatment of dementia and a known contributor to institutionalization of patients with dementia. Published data have documented increased caregiver burden in behavioral variant frontotemporal dementia (bvFTD) compared to Alzheimer's disease (AD). Another atypical dementia with high-perceived caregiver burden is sporadic Creutzfeldt-Jakob disease (sCJD), but no formal studies have assessed this perception. The aim of this study was to compare caregiver burden across atypical dementia etiologies. METHODS: 76 adults with atypical dementia (young-onset AD [YOAD], bvFTD, language variant FTD [lvFTD], and sCJD) were administered an abbreviated version of the Zarit Burden Interview (ZBI), Neuropsychiatric Inventory (NPI-Q), and other assessment instruments during a five-year time period at Johns Hopkins Hospital (JHH). A Cox regression model examined differences between disease categories that impact mean ZBI scores. RESULTS: Mean ZBI scores were significantly different between dementia etiologies, with bvFTD and sCJD having the highest caregiver burden (p = 0.026). Mean NPI-Q caregiver distress scores were highest in bvFTD and sCJD (p = 0.002), with sCJD and bvFTD also having the highest number of endorsed symptom domains (p = 0.012). On regression analyses, an interactive variable combining final diagnosis category and NPI-Q total severity score demonstrated statistically significant differences in mean ZBI scores for sCJD and bvFTD. CONCLUSIONS: This study demonstrates that bvFTD and sCJD have increased levels of caregiver burden, NPI-Q caregiver distress, total severity scores, and number of endorsed symptom domains. These results suggest that higher caregiver burden in bvFTD and sCJD are disease specific and possibly related to neuropsychiatric symptoms.

An International Survey-based Algorithm for the Pharmacologic Treatment of Irritability in Huntington's Disease.

It is generally believed that treatments are available to manage irritability in Huntington's disease (HD). However, lack of an evidence base prevents the establishment of treatment guidelines for this symptom. The research literature fails to address behavioral intervention strategies, drug selection, drug dosing, management of inadequate response to a single drug, or preferred drugs when additional behavioral symptoms comorbid to irritability are present. In an effort to inform clinical decision-making we surveyed an international group of experts to address these points. The experts consistently endorsed an antipsychotic drug (APD) as first choice for treatment of urgent and aggressive irritability behaviors. However, there was variation in practice patterns for treating less severe symptoms. Serotonin reuptake inhibitors (SSRIs) were first choice drug treatments by most respondents across all geographic regions. However, APDs were also endorsed as first choice for mild or moderate irritability, more frequently in Europe than in North America and Australia. Antiepileptic mood stabilizers (AEDs) were used by fewer respondents as first choice drug. Perceived efficacy for control of mild or moderate irritability was judged somewhat higher for APDs than SSRIs or AEDs. Benzodiazepines were not used as monotherapy, but frequently as an adjunctive drug in the setting of comorbid anxiety. Though many cited lack of experience with mirtazapine, others familiar with its use in HD chose it as an alternative monotherapy, or as adjunctive therapy if insomnia was a comorbid factor. This report presents survey results, reviews available irritability studies, and lastly proposes an algorithm for the treatment of irritability in HD derived from expert preferences obtained through this survey.

An International Survey-based Algorithm for the Pharmacologic Treatment of Obsessive-Compulsive Behaviors in Huntington's Disease.

It is generally believed that treatments are available to manage obsessive-compulsive behaviors (OCB's) in Huntington's disease (HD). However, lack of an evidence base prevents guideline development. The research literature fails to address the indications for behavioral interventions, drug selection, drug dosing, management of inadequate response to a single drug, and preferred drugs when additional behavioral symptoms comorbid to OCBs are present. In an effort to inform clinical decision-making, we surveyed an international group of experts to address these points. Survey results showed that experts utilized behavioral therapy only for patients with mild cognitive impairment. There was expert agreement that a selective serotonin reuptake inhibitor (SSRI) was the first choice drug, although clomipramine (CMI) was cited as a monotherapy choice by the smaller number of experts familiar with its use. Perceived efficacy for control of OCBs was similar for both SSRIs and CMI. Though less favored choices overall, antipsychotics (APDs) and antiepileptic mood stabilizers (AEDs) were most often used as augmentation strategies. In addition to survey results, this report reviews available studies, and lastly presents an algorithm for the treatment of OCBs in HD based on practice-based preferences obtained from this survey.