Huntington's disease

Cognitive Impairment in Neurodegenerative Movement Disorders

Patients with neurodegenerative movement disorders can develop cognitive impairment during the disease. Cognitive symptoms have been associated with decreased quality of life, higher caregiver burden, and earlier institutionalization, and are therefore critical for physicians to understand and address. The evaluation of cognitive performance of patients with neurodegenerative movement disorders is important for providing adequate diagnosis, management, prognosis, and support patients and their caregivers. In this review, we discuss the features of the cognitive impairment profile of commonly encountered movement disorders: Parkinson's disease, dementia with Lewy bodies, multiple system atrophy, progressive supranuclear palsy, corticobasal syndrome, and Huntington's disease. In addition, we provide neurologists with practical guidance and evaluation tools for the assessment and management of these challenging patients.

The role of ferroptosis in neurodegenerative diseases

Ferroptosis is newly identified as a non-apoptotic form of programmed cell death. It is characterized by iron-dependent intracellular accumulation of lipid peroxides which ultimately leads to oxidative stress and cell death. Ferroptosis has been identified in several diseases, such as cancer, renal failure, liver injury, and ischemia-reperfusion injury. Besides, it has been reported to be involved in the pathological mechanism of neurodegenerative diseases (NDD). In addition, interventions targeting ferroptosis can influence the course of NDD, making it a potential therapeutic target for NDD. By summarizing the current research on ferroptosis and its impact on many neurological diseases, we hope to provide valuable strategies for the underlying mechanisms and treatment of these neurological diseases.

Alteration of Autophagy and Glial Activity in Nilotinib-Treated Huntington's Disease Patients

Nilotinib is a tyrosine kinase inhibitor that is safe and tolerated in neurodegeneration, it achieves CSF concentration that is adequate to inhibit discoidin domain receptor (DDR)-1. Nilotinib significantly affects dopamine metabolites, including Homovanillic acid (HVA), resulting in an increase in brain dopamine. HD is a hereditary disease caused by mutations in the Huntingtin's (HTT) gene and characterized by neurodegeneration and motor and behavioral symptoms that are associated with activation of dopamine receptors. We explored the effects of a low dose of nilotinib (150 mg) on behavioral changes and motor symptoms in manifest HD patients and examined the effects of nilotinib on several brain mechanisms, including dopamine transmission and gene expression via cerebrospinal fluid (CSF) miRNA sequencing. Nilotinib, 150 mg, did not result in any behavioral changes, although it significantly attenuated HVA levels, suggesting reduction of dopamine catabolism. There was no significant change in HTT, phosphorylated neuro-filament and inflammatory markers in the CSF and plasma via immunoassays. Whole miRNA genome sequencing of the CSF revealed significant longitudinal changes in miRNAs that control specific genes associated with autophagy, inflammation, microglial activity and basal ganglia neurotransmitters, including dopamine and serotonin.

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.

An unusual presentation of Huntington's disease

We describe the case of a 59-year-old woman who exhibited psychotic symptoms, cognitive dysfunction, and restlessness. While the clinical picture and 18F-FDG PET/CT suggested the presence of a tauopathy, especially frontotemporal dementia or progressive supranuclear palsy, genetic testing eventually revealed Huntington's disease.

Impact of Chorea on Self-care Activity, Employment, and Health-care Resource Use in Patients with Huntington's Disease

Background: Chorea is recognized as a prototypic motor feature of Huntington's disease (HD), but its effect on health-related quality of life (HRQoL) has not been fully explored. This study describes the impact of chorea on HRQoL in patients with HD. Objective: To determine the impact of HD-related chorea on employment, self-care activities, activities of daily living, and health-care resource utilization (HCRU). Methods: Data were drawn from the Adelphi HD Disease Specific Programme, a real-world point-in-time survey of 144 neurologists and 427 patients in the United States between July and October 2017. HD patients with and without chorea were identified and examined for differences in employment status, reasons for employment changes, self-care activities, and modifications to cope with involuntary movements. Bivariate tests and inverse probability weighted regression adjustment methods were used to determine differences in outcomes between patients with and without chorea. Results: HD patients with (n=287) and without (n=140) chorea were identified. Patients with chorea were less likely to be employed full-time (16.7% vs 25.7%; P<0.04) and more likely to be on long-term sick leave (17.4% vs 5.0%; P<0.01). The onset of motor symptoms in HD-related chorea patients coincided with a change in employment status (42.7% vs 20.8%; P<0.01). Among those still working (n=145), more than two-fifths of patients with chorea required changes to their workplace and required these changes more frequently (45% vs 17%; P<0.001). HD patients with chorea required aid to help them get around significantly more frequently than those without chorea (55% vs 34%; P<0.001). Discussion: These results demonstrate that HD patients with chorea experienced greater negative impact to employment, self-care activities, and HCRU than patients without chorea experienced. These patients were more likely to stop working due to motor, cognitive, and behavioral symptoms; require modifications in the home and workplace; and need more assistance from caregivers than patients without chorea. Conclusions: Patients with HD-related chorea have greater detriments to emotional, interpersonal, and professional functioning that could be improved by reducing chorea.

Understanding How Chorea Affects Health-Related Quality of Life in Huntington Disease: An Online Survey of Patients and Caregivers in the United States

BACKGROUND

Chorea is the hallmark motor feature of Huntington disease (HD) and can negatively impact daily functioning and health-related quality of life (HRQoL).

OBJECTIVE

The objective of this study was to evaluate how chorea impacts HRQoL and overall functioning among HD patients participating on the PatientsLikeMe website ( www.PatientsLikeMe.com ).

METHODS

A survey was provided to HD participants and/or their caregivers via PatientsLikeMe (9 February 2017-22 March 2017), comprising multiple-choice and open-ended questions designed to assess how chorea impacts HRQoL and overall functioning, and the importance of treating chorea. The HDQLIFE measurement system was used to evaluate patient-reported outcomes of chorea and compare Anxiety and Stigma scores in participants with high chorea versus those with low chorea [HDQLIFE Chorea scores ≥  60 (n = 45) vs. <  60 (n = 38)].

RESULTS

A total of 115 participants (n = 35 caregivers; n = 80 individuals with HD) were included in this study. Among those experiencing chorea (n = 83, 74% of respondents), 66% indicated it was 'Very Important' to manage chorea; however, only 47% agreed that their current medication regimen helped manage their movements. In general, respondents reported that chorea negatively affected HRQoL [HDQLIFE Chorea mean score (standard deviation): 59.3 (6.1)]. Consistent with this, significantly higher Anxiety (P = 0.0423) and stigma (P < 0.0001) scores were observed among respondents with high chorea than in those with low chorea.

CONCLUSIONS

These results highlight the negative impact of chorea on HRQoL and overall functioning in individuals with HD. Better chorea treatment options are needed to successfully manage symptoms and to help improve HRQoL in these individuals, and patient experiences of anxiety and stigma should be considered in treatment plans.

Retrospective Analysis of Healthcare Resource Use, Treatment Patterns, and Treatment-related Events in Patients with Huntington's Disease-associated Chorea Initiated on Tetrabenazine

BACKGROUND

Huntington's disease (HD) is a multifaceted neurodegenerative disorder characterized by involuntary movements, specifically chorea, as well as behavioral and psychiatric disturbance, and cognitive dysfunction. Tetrabenazine was the first approved treatment for chorea, although tolerability concerns exist.

OBJECTIVES

To characterize demographic and clinical characteristics of HD patients with chorea based on tetrabenazine use and examine treatment persistence with tetrabenazine in a real-world setting.

METHODS

Patients with a claim for HD-associated chorea (ICD-9-CM code 333.4) between 1/1/08 and 9/30/15 were selected from the MarketScan^® Commercial and Medicare Supplemental databases. The first diagnosis date during the study period was considered the index date, with ≥6 months of continuous medical and prescription coverage before and after the index date. Treatment persistence was defined as the number of days from initiation to discontinuation or end of follow-up period. Discontinuation was defined as a gap in therapy of ≥60 days.

RESULTS

1644 patients met selection criteria (mean age ± standard deviation: 54.5 ± 15.5), of which 151 (9.2%) were treated with tetrabenazine during the study period. The average (median) daily dose of tetrabenazine during the treatment period was 45.5 (42.3) mg/day. A total of 41.8% (59/141) of HD patients who initiated tetrabenazine experienced a ≥60-day gap in tetrabenazine therapy, with a median time to discontinuation of 293.5 days. During the 6-month post-index period after HD diagnosis, HD patients incurred higher all-cause healthcare costs ($20 204) vs the 6-month pre-index period ($6057), driven by higher hospitalization and pharmacy costs.

CONCLUSIONS

A small percentage of HD patients with chorea were treated with tetrabenazine and discontinuation rates were high among those receiving treatment, with a median time to discontinuation of 9 months.

Thermoregulatory disorders in Huntington disease

Huntington disease (HD) is a paradigmatic autosomal-dominant adult-onset neurodegenerative disease. Since the identification of an abnormal expansion of a trinucleotide repeat tract in the huntingtin gene as the underlying genetic defect, a broad range of transgenic animal models of the disease has become available and these have helped to unravel the relevant molecular pathways in unprecedented detail. Of note, some of the most informative of these models develop thermoregulatory defects such as hypothermia, problems with adaptive thermogenesis, and an altered circadian temperature rhythm. Both central, e.g., in the hypothalamus and peripheral, i.e., the brown adipose tissue and skeletal muscle, problems contribute to the phenotype. Importantly, these structures and pathways are also affected in human HD. Yet, currently the evidence for bona fide thermodysregulation in human HD patients remains anecdotal. This may be due to a lack of reliable tools for monitoring body temperature in an outpatient setting. Regardless, study of the temperature phenotype has contributed to the identification of unexpected molecular targets, such as the PGC-1α pathway.