Listener Detection of Objectively Validated Acoustic Features of Speech in Huntington’s Disease

Background: Subtle progressive changes in speech motor function and cognition begin prior to diagnosis of Huntington’s disease (HD). Objective: To determine the nature of listener-rated speech differences in premanifest and early-stage HD (i.e., PreHD and EarlyHD), compared to neurologically healthy controls. Methods: We administered a speech battery to 60 adults (16 people with PreHD, 14 with EarlyHD, and 30 neurologically healthy controls), and conducted a cognitive test of processing speed/visual attention, the Symbol Digit Modalities Test (SDMT) on participants with HD. Voice recordings were rated by expert listeners and analyzed for acoustic and perceptual speech features. Results: Listeners perceived subtle differences in the speech of PreHD compared to controls, including abnormal pitch level and speech rate, reduced loudness and loudness inflection, altered voice quality, hypernasality, imprecise articulation, and reduced naturalness of speech. Listeners detected abnormal speech rate in PreHD compared to healthy speakers on a reading task, which correlated with slower speech rate from acoustic analysis and a lower cognitive performance score. In early-stage HD, continuous speech was characterized by longer pauses, a higher proportion of silence, and slower rate. Conclusion: Differences in speech and voice acoustic features are detectable in PreHD by expert listeners and align with some acoustically-derived objective speech measures. Slower speech rate in PreHD suggests altered oral motor control and/or subtle cognitive deficits that begin prior to diagnosis. Speakers with EarlyHD exhibited more silences compared to the PreHD and control groups, raising the likelihood of a link between speech and cognition that is not yet well characterized in HD.

A Double-Pronged Sword: XJB-5-131 Is a Suppressor of Somatic Instability and Toxicity in Huntington’s Disease

Due to large increases in the elderly populations across the world, age-related diseases are expected to increase dramatically in the coming years. Among these, neurodegenerative diseases will be among the most devastating in terms of their emotional and economic impact on patients, their families, and associated subsidized health costs. There is no currently available cure or rescue for dying brain cells. Viable therapeutics for any of these disorders would be a breakthrough and provide relief for the large number of affected patients and their families. Neurodegeneration is accompanied by elevated oxidative damage and inflammation. While natural antioxidants have largely failed in clinical trials, preclinical phenotyping of the properties of the unnatural, mitochondrial targeted nitroxide, XJB-5-131, bodes well for further translational development in advanced animal models or in humans. Here we consider the usefulness of synthetic antioxidants for the treatment of Huntington’s disease. The mitochondrial targeting properties of XJB-5-131 have great promise. It is both an electron scavenger and an antioxidant, reducing both somatic expansion and toxicity simultaneously through the same redox mechanism. By quenching reactive oxygen species, XJB-5-131 breaks the cycle between the rise in oxidative damage during disease progression and the somatic growth of the CAG repeat which depends on oxidation.

Olfactory Dysfunction in Huntington’s Disease

Olfactory dysfunction is a common symptom in patients with neurodegenerative disorders, including Huntington’s disease (HD). Understanding its pathophysiology is important in establishing a preventive and therapeutic plan. In this literature review, we cover the physiology of olfaction, its role in neurodegeneration, and its characteristics in patients with HD. In the general population, olfactory dysfunction is present in 3.8–5.8%and the prevalence increases significantly in those older than 80 years. For HD, data regarding prevalence rates are lacking and the scales used have been inconsistent or have been restructured due to concerns about cross-cultural understanding. Pathogenic huntingtin deposits have been found in the olfactory bulb of individuals with HD, although no studies have correlated this with the grade of olfactory impairment. Olfactory dysfunction is present in both premanifest and manifest patients with HD, showing a progressive decline over time with more severe deficits at advanced stages. No specific treatment for olfactory impairment in HD has been proposed; identifying and avoiding potential medications that cause olfactory dysfunction, as well as general safety recommendations remain the basis of the therapeutic strategy.

Improving Patient Outreach by Defining Telehealth Suitability in a Tertiary Huntington’s Disease Clinic

Background: The COVID-19 pandemic has increased the need for remote healthcare options among patients with Huntington’s disease (HD). However, since not every HD patient is suitable for telehealth, it is important to differentiate who can be seen virtually from who should remain as in-person. Unfortunately, there are no clinical guidelines on how to evaluate HD patients for telehealth eligibility. Objective: To standardize the teleneurology selection process in HD by implementing a screening tool that accounts for patient-specific factors. Methods: We organized various indications and contraindications to teleneurology into a flowchart. If any indications or contraindications were met, patients were assigned to telehealth or maintained as in-person, respectively. If no indications or contraindications were met, patients were given the option of telehealth or in-person for their upcoming appointments. In two implementation cycles, we tested this screening tool among all HD patients scheduled for clinic visits, aided by chart review and phone interview. Results: In a cohort of 81 patients, telehealth acceptance among eligible patients increased from 45.0%to 83.3%. Frequency of telehealth visits increased from a pre-intervention baseline of 12.8%to 28.2%. Conclusion: Teleneurology utilization among HD patients more than doubled across our study. Our intervention promotes consistency and patient-centeredness in HD clinical care and streamlines the overall telehealth selection process. Future studies can seek to reduce telehealth no-shows and also evaluate the utility of the motor and psychiatric criteria included in our screening tool.

Falls, Fear of Falling, and Preventive Measures in Huntington’s Disease: The Perspectives of Individuals with Huntington’s Disease and Caregivers in Long-Term Care

Background: Falls are common in Huntington’s disease (HD), which can have serious consequences and may therefore lead to fear of falling (FoF). There is little knowledge about falls or FoF in individuals with HD or about formal and informal caregivers’ fear about falls in individuals with HD. Objective: To explore prevalence of falls, FoF and fall preventive measures both those applied and those not included in managing falls in individuals with HD and their formal and informal caregivers, and to identify the relationship between FoF and, anxiety, awareness and cognitive functioning respectively. Methods: In a multi-center observational cross-sectional study, care-independent and -dependent individuals with HD and their formal and informal caregivers were recruited from six Dutch nursing homes specialized in HD. The participants were assessed by means of questionnaires enquiring about falls, FoF, awareness of fall risk, cognition, anxiety and fall preventive measures. Results: For all included 158 individuals with HD, the fall prevalence over the last 30 days was 28.8%. The prevalence of FoF in individuals with HD, formal caregivers and informal caregivers was 47.6%, 25.6%, and 63.5%, respectively, for care-independent individuals with HD and 46.9%, 26.3%, and 62.0%, respectively, for care-dependent individuals with HD. Anticipatory awareness of fall risks and gender are predictors of FoF in care-independent individuals with HD, though not in the care-dependent group. A combination of fall preventive measures is used in most individuals with HD. Conclusion: Fall prevalence is high and FoF is common in individuals with HD and their caregivers. Gender and anticipatory awareness are risk factors for FoF. In addition to the use of individual multifactorial fall prevention strategies, it is important to support both formal and informal caregivers in coping with falls

Quantifying the Onset of Unintended Weight Loss in Huntington’s Disease: A Retrospective Analysis of Enroll-HD

Background: Unintended weight loss and decreased body mass indexes (BMIs) are common symptoms of individuals with manifest HD. It is unknown at what point during disease progression weight loss starts to accelerate relative to a healthy individual’s weight and when recommended interventions should be initiated to have the strongest impact on patient care. Objective: The objective of this study was to identify a point in time relative to age at motor onset when the decline in weight in HD starts to accelerate relative to a non-HD population. The relationship between initiation of weight loss interventions and changes in weight loss was also explored. Methods: Participants from the fifth version of the Enroll-HD study were identified for this research. Linear mixed-effects piecewise regression models were used to estimate the point in time relative to the reported age of motor onset in which BMI started to decline in participants with HD compared to healthy non-HD controls. A post-hoc descriptive analysis was performed to look at when nutritional supplements and swallow therapy were initiated in participants with HD relative to motor onset. Results: BMI decline in the HD group began to accelerate compared to controls approximately 5.7 years after the reported age of motor onset (95% CI: 4.7–6.9). The average initiation times of swallow therapy and nutritional supplements were 7.7 years (SD = 5.5 years) and 6.7 years (SD = 6.5 years) after motor onset, respectively. Conclusion: Our findings suggest a potential point for intervention of nutrition programs or therapies used to prevent future weight loss.

Arithmetic Word-Problem Solving as Cognitive Marker of Progression in Pre-Manifest and Manifest Huntington’s Disease

Background: Arithmetic word-problem solving depends on the interaction of several cognitive processes that may be affected early in the disease in gene-mutation carriers for Huntington’s disease (HD). Objective: Our goal was to examine the pattern of performance of arithmetic tasks in premanifest and manifest HD, and to examine correlations between arithmetic task performance and other neuropsychological tasks. Methods: We collected data from a multicenter cohort of 165 HD gene-mutation carriers. The sample consisted of 31 premanifest participants: 16 far-from (>12 years estimated time to diagnosis; preHD-A) and 15 close-to (≤12 years estimated time to diagnosis; preHD-B), 134 symptomatic patients (early-mild HD), and 37 healthy controls (HC). We compared performance between groups and explored the associations between arithmetic word-problem solving and neuropsychological and clinical variables. Results: Total arithmetic word-problem solving scores were lower in preHD-B patients than in preHD-A (p < 0.05) patients and HC (p < 0.01). Early-mild HD patients had lower scores than preHD patients (p < 0.001) and HC (p < 0.001). Compared to HC, preHD and early-mild HD participants made more errors as trial complexity increased. Moreover, arithmetic word-problem solving scores were significantly associated with measures of global cognition (p < 0.001), frontal-executive functions (p < 0.001), attention (p < 0.001) and visual working memory (p < 0.001), mental rotation (p < 0.001), and confrontation naming (p < 0.05). Conclusion: Arithmetic word-problem solving is affected early in the course of HD and is related to deficient processes in frontal-executive and mentalizing-related processes.

Age-Dependent Degradation of Locomotion Encoding in Huntington’s Disease R6/2 Model Mice

Background: Huntington’s disease (HD) is an inherited fatal neurodegenerative disease, leading to neocortical and striatal atrophy. The commonly studied R6/2 HD transgenic mouse model displays progressive motor and cognitive deficits in parallel to major pathological changes in corticostriatal circuitry. Objective: To study how disease progression influences striatal encoding of movement. Methods: We chronically recorded neuronal activity in the dorsal striatum of R6/2 transgenic (Tg) mice and their age-matched nontransgenic littermate controls (WTs) during novel environment exposure, a paradigm which engages locomotion to explore the novel environment. Results: Exploratory locomotion degraded with age in Tg mice as compared to WTs. We encountered fewer putative medium spiny neurons (MSNs)—striatal projection neurons, and more inhibitory interneurons—putative fast spiking interneurons (FSIs) in Tg mice as compared to WTs. MSNs from Tg mice fired less spikes in bursts without changing their firing rate, while FSIs from these mice had a lower firing rate and more of them were task-responsive as compared to WTs. Additionally, MSNs from Tg mice displayed a reduced ability to encode locomotion across age groups, likely associated with their low prevalence in Tg mice, whereas the encoding of locomotion by FSIs from Tg mice was substantially reduced solely in old Tg mice as compared to WTs. Conclusion: Our findings reveal an age-dependent decay in striatal information processing in transgenic mice. We propose that the ability of FSIs to compensate for the loss of MSNs by processes of recruitment and enhanced task-responsiveness diminishes with disease progression, possibly manifested in the displayed age-dependent degradation of exploratory locomotion.

Huntington’s Disease in Israel: A Population-based Study Using 20 Years of Routinely-Collected Healthcare Data

Background: Huntington’s disease (HD) is a rare, genetic, neurodegenerative disease. Obtaining population-level data on epidemiology and disease management is challenging. Objective: To investigate the epidemiology, clinical manifestations, treatment, and healthcare utilization of patients with HD in Israel. Methods: Retrospective population-based cohort study, including 20 years of routinely collected data from Maccabi Healthcare Services, an insurer and healthcare provider for one-quarter of the Israeli population. Results: The study cohort included 109 adult patients (aged ≥18 years) diagnosed with HD, with mean age of 49.9 years and 56%females. The most common HD-related conditions were anxiety (40%), behavioral problems (34%), sleep disorders (21%), and falls (13%). Annual incidence rates for HD ranged from 0.17 to 1.34 per 100,000 from 2000 to 2018; the 2018 crude prevalence in adults was 4.36 per 100,000. Median survival from diagnosis was approximately 12 years (95%CI: 10.4–15.3). The most frequent symptomatic treatments were antidepressants (69%), antipsychotics (63%), and tetrabenazine (63%), the only drug approved for the treatment of HD chorea in Israel during the examined period. Patterns of healthcare utilization changed as disease duration increased, reflected by increased frequency of emergency department visits and home visits. Conclusion: This retrospective population-based study provides insights into the prevalence, incidence, clinical profile, survival, and resource utilization of patients with HD in ethnically diverse Israel. The findings in this study are generally consistent with the international literature and demonstrate the value of routinely collected healthcare data as a complementary resource in HD research.