Evaluating motor progression of juvenile-onset Huntington's Disease: An Enroll-HD analysis

INTRODUCTION

Juvenile-onset Huntington's disease (JOHD) is characterized by a unique motor phenotype relative to patients with adult-onset Huntington's Disease (AOHD). This study characterized motor progression of JOHD to propose improved outcome measures for this group.

METHODS

We used linear mixed effect regression models to compare progression of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score (TMS) and the chorea score between patients with JOHD and AOHD. We then evaluated all 31 subscales that make up the UHDRS over time within patients with JOHD to identify measures that may be used to track motor progression most reliably.

RESULTS

The JOHD cohort had faster TMS progression compared to AOHD (p = 0.006) but no group difference in the rate of change of chorea. Patients with JOHD did not show significant change in any of the chorea subscales. The subscales that changed most reliably over time amongst patients with JOHD were dysarthria, upper extremity dystonia, tandem walking, gait, bilateral pronate/supinate, bilateral finger-tapping, and tongue protrusion. When these subscales were summed, they progressed at a faster rate (7.07%, 95% CI [5.96-8.18]) than the TMS (4.92%, 95% CI [3.95-5.89]).

CONCLUSION

While the TMS changes at a significant rate in JOHD subjects, not all subscales that make up the TMS accurately represent the unique motor features of JOHD. A JOHD-specific scale performed better at tracking motor progression relative to the TMS. This scale may improve clinical care for patients with JOHD and allow for the development of more efficient clinical trials.

Unravelling the role of huntingtin: from neurodevelopment to neurodegeneration

This scientific commentary refers to ‘Genetic topography and cortical cell loss in Huntington’s disease link development and neurodegeneration’ by Estevez-Fraga et al. (https://doi.org/10.1093/brain/awad275).

Memantine Use and Cognitive Decline in Huntington's Disease: An Enroll-HD Study

Background

Memantine is an N-methyl-d-aspartate (NMDA) receptor antagonist that is used to treat moderate to severe Alzheimer's Dementia (AD) and has been speculated to provide clinical benefits in Huntington's disease (HD).

Objective

To assess the effectiveness of memantine on the trajectory of cognitive decline in individuals with manifest HD.

Methods

Using participants from the Enroll-HD study, the primary analysis compared trajectories in cognition over a 5-year period using linear mixed effect models of prevalent and incident memantine users who were propensity-score-matched with non-users on measures of disease progression and demographics.

Results

In the primary analysis there were no significant differences in the trajectories between memantine users and non-users on any primary outcomes of interest.

Conclusions

Memantine use was not associated with any clinical benefit for individuals with manifest HD. Further studies are warranted to assess the impact of memantine on clinical outcomes in HD.

Longitudinal Clinical and Biological Characteristics in Juvenile-Onset Huntington's Disease

BACKGROUND

Juvenile-onset Huntington's disease (JOHD) is a rare form of Huntington's disease (HD) characterized by symptom onset before the age of 21 years. Observational data in this cohort is lacking.

OBJECTIVES

Quantify measures of disease progression for use in clinical trials of patients with JOHD.

METHODS

Participants who received a motor diagnosis of HD before the age of 21 were included in the Kids-JOHD study. The comparator group consisted of children and young adults who were at-risk for inheriting the genetic mutation that causes HD, but who were found to have a CAG repeat in the non-expanded range (gene non-expanded [GNE]).

RESULTS

Data were obtained between March 17, 2006, and February 13, 2020. There were 26 JOHD participants and 78 GNE participants who were comparable on age (16.03 vs. 14.43, respectively) and sex (53.8% female vs. 57.7% female, respectively). The mean annualized decrease in striatal volume in the JOHD group was -3.99% compared to -0.06% in the GNE (mean difference [MD], -3.93%; 95% confidence intervals [CI], [-4.98 to -2.80], FDR < 0.0001). The mean increase in the Unified Huntington's Disease Rating Scale Total Motor Score per year in the JOHD group was 7.29 points compared to a mean decrease of -0.21 point in the GNE (MD, 7.5; 95% CI, [5.71-9.28], FDR < 0·0001).

CONCLUSIONS

These findings demonstrate that structural brain imaging and clinical measures in JOHD may be potential biomarkers of disease progression for use in clinical trials. Collaborative efforts are required to validate these results in a larger cohort of patients with JOHD. © 2022 International Parkinson and Movement Disorder Society.

The effects of antidepressants on depressive symptoms in manifest Huntington's disease

OBJECTIVE

Currently there is little evidence to guide the treatment of depression in Huntington's disease (HD). The primary objective was to determine the effectiveness of antidepressant medications on lowering depressive symptom scores in patients with manifest HD. The secondary objective was to determine the effect of antidepressant use on measures of disease progression.

METHODS

After retrospectively identifying motor-manifest HD participants with at least borderline depressive symptoms from the Enroll-HD database, 86 new users of antidepressant medication were exact matched with non-users on depression score, and matched on propensity scores developed using age, sex, CAG repeat length, anxiety scores, and disease progression measures. Linear mixed effect models were used to assess the change in depression scores, anxiety scores, and disease progression measures based on antidepressant use between two visits approximately one-year apart.

RESULTS

There was no significant difference in the change in depression score between antidepressant users and non-users (p = 0.46). There were also no significant differences in the change in total motor score (p = 0.88), total functional capacity score (p = 0.16), number correct on the symbol digit modality test (p = 0.49), or anxiety score (p = 0.68).

CONCLUSIONS

Initiation of antidepressant medication was not associated with a greater reduction in depressive symptoms or changes in other symptoms when compared to non-use. The findings of this study support further research on the effectiveness of antidepressants in Huntington's disease patients. Clinical trials or studies with a larger sample of new antidepressant users should be used to assess the causal effects of antidepressant medications on depressive symptoms.

Behavioral features in child and adolescent huntingtin gene-mutation carriers

INTRODUCTION

We compared neuropsychiatric symptoms between child and adolescent huntingtin gene-mutation carriers and noncarriers. Given previous evidence of atypical striatal development in carriers, we also assessed the relationship between neuropsychiatric traits and striatal development.

METHODS

Participants between 6 and 18 years old were recruited from families affected by Huntington's disease and tested for the huntingtin gene expansion. Neuropsychiatric traits were assessed using the Pediatric Behavior Scale and the Behavior Rating Inventory of Executive Function. Striatal volumes were extracted from 3T neuro-anatomical images. Multivariable linear regression models were conducted to evaluate the impact of group (i.e., gene nonexpanded [GNE] or gene expanded [GE]), age, and trajectory of striatal growth on neuropsychiatric symptoms.

RESULTS

There were no group differences in any behavioral measure with the exception of depression/anxiety score, which was higher in the GNE group compared to the GE group (estimate = 4.58, t(129) = 2.52, FDR = 0.051). The growth trajectory of striatal volume predicted depression scores (estimate = 0.429, 95% CI 0.15:0.71, p = .0029), where a negative slope of striatal volume over time was associated with lower depression/anxiety.

CONCLUSIONS

The current findings show that GE children may have lower depression/anxiety compared to their peers. Previously, we observed a unique pattern of early striatal hypertrophy and continued decrement in volume over time among GE children and adolescents. In contrast, GNE individuals largely show striatal volume growth. These findings suggest that the lower scores of depression and anxiety seen in GE children and adolescents may be associated with differential growth of the striatum.

Neurofilament Light Protein as a Potential Blood Biomarker for Huntington's Disease in Children

BACKGROUND

Juvenile-onset Huntington's disease (JOHD) is a rare and particularly devastating form of Huntington's disease (HD) for which clinical diagnosis is challenging and robust outcome measures are lacking. Neurofilament light protein (NfL) in plasma has emerged as a prognostic biomarker for adult-onset HD.

METHODS

We performed a retrospective analysis of samples and data collected between 2009 and 2020 from the Kids-HD and Kids-JHD studies. Plasma samples from children and young adults with JOHD, premanifest HD (preHD) mutation carriers, and age-matched controls were used to quantify plasma NfL concentrations using ultrasensitive immunoassay.

RESULTS

We report elevated plasma NfL concentrations in JOHD and premanifest HD mutation-carrying children. In pediatric HD mutation carriers who were within 20 years of their predicted onset and patients with JOHD, plasma NfL level was associated with caudate and putamen volumes.

CONCLUSIONS

Quantifying plasma NfL concentration may assist clinical diagnosis and therapeutic trial design in the pediatric population. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson Movement Disorder Society.

Autonomic changes in Huntington's disease correlate with altered central autonomic network connectivity

Autonomic dysfunction has been described in patients with Huntington's disease, but it is unclear if these changes in autonomic tone are related to the central autonomic network. We performed a pilot study to investigate the relationship between the integrity of the central autonomic network and peripheral manifestiations of autonomic dysfunction in premanifest Huntington's disease. We recruited male participants with pre-motor-manifest Huntington's disease and a comparison group consisting of healthy, male participants of approximately the same age. As this was a pilot study, only males were included to reduce confounding. Participants underwent a resting-state functional magnetic resonance imaging study to quantify functional connectivity within the central autonomic network, as well as a resting 3-lead ECG to measure heart rate variability with a particular focus on the parasympathetic time-domain measures of root mean square of successive differences between normal heartbeats. The pre-motor-manifest Huntington's disease participants had significantly decreased root mean square of successive differences between normal heartbeats values compared with the healthy comparison group. The pre-motor-manifest Huntington's disease group had significantly lower functional connectivity within the central autonomic network, which was positively correlated with root mean square of successive differences between normal heartbeats. Patients with pre-motor-manifest Huntington's disease have reduced functional connectivity within the central autonomic network, which is significantly associated with observed changes in autonomic function.

A pilot to assess target engagement of terazosin in Parkinson's disease

BACKGROUND

Impaired brain energy metabolism is a key feature of Parkinson's disease (PD). Terazosin (TZ) binds phosphoglycerate kinase 1 and stimulates its activity, which enhances glycolysis and increases ATP levels. Preclinical and epidemiologic data suggest that TZ may be neuroprotective in PD. We aimed to assess target engagement and safety of TZ in people with PD.

METHODS

We performed a 12-week pilot study in people with PD. Participants were randomized to receive 5 mg TZ or placebo. Participants and study personnel were blinded. We assessed TZ target engagement by measuring brain ATP with ³¹P-magnetic resonance spectroscopy (MRS) and whole blood ATP with a luminescence assay. Robust linear regression models compared changes between groups controlling for baseline brain and blood ATP levels, respectively. We also assessed clinical measures of PD and adverse events.

RESULTS

Thirteen participants were randomized. Mild dizziness/lightheadedness was more common in the TZ group, and three participants taking TZ dropped out because of dizziness and/or orthostatic hypotension. Compared to the placebo group, the TZ group had a significant increase in the ratio of βATP to inorganic phosphate in the brain. The TZ group also had a significant increase in blood ATP levels compared to the placebo group (p < 0.01).

CONCLUSIONS

This pilot study suggests that TZ may engage its target and change ATP levels in the brain and blood of people with PD. Further studies may be warranted to test the disease-modifying potential of TZ.

COVID-19 Case Fatality and Alzheimer's Disease

Previous studies have identified dementia as a risk factor for death from coronavirus disease 2019 (COVID-19). However, it is unclear whether Alzheimer's disease (AD) is an independent risk factor for COVID-19 case fatality rate. In a retrospective cohort study, we identified 387,841 COVID-19 patients through TriNetX. After adjusting for demographics and comorbidities, we found that AD patients had higher odds of dying from COVID-19 compared to patients without AD (Odds Ratio: 1.20, 95%confidence interval: 1.09-1.32, p < 0.001). Interestingly, we did not observe increased mortality from COVID-19 among patients with vascular dementia. These data are relevant to the evolving COVID-19 pandemic.

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.

The Neurodevelopmental Hypothesis of Huntington's Disease

The current dogma of HD pathoetiology posits it is a degenerative disease affecting primarily the striatum, caused by a gain of function (toxicity) of the mutant mHTT that kills neurons. However, a growing body of evidence supports an alternative theory in which loss of function may also influence the pathology.This theory is predicated on the notion that HTT is known to be a vital gene for brain development. mHTT is expressed throughout life and could conceivably have deleterious effects on brain development. The end event in the disease is, of course, neurodegeneration; however the process by which that occurs may be rooted in the pathophysiology of aberrant development.To date, there have been multiple studies evaluating molecular and cellular mechanisms of abnormal development in HD, as well as studies investigating abnormal brain development in HD animal models. However, direct study of how mHTT could affect neurodevelopment in humans has not been approached until recent years. The current review will focus on the most recent findings of a unique study of children at-risk for HD, the Kids-HD study. This study evaluates brain structure and function in children ages 6-18 years old who are at risk for HD (have a parent or grand-parent with HD).

Sleep disturbances by disease type and stage in Huntington's disease

INTRODUCTION

Sleep disturbances are a common symptom in patients with Huntington's disease (HD). However, it is unclear when in the disease course of HD sleep disturbances become more frequent compared to the general population. This study investigated the frequency and odds of developing sleep disturbances between adults with HD or at-risk for HD and non-HD controls.

METHODS

Participants from the Enroll-HD study were split by both disease type and disease severity using CAG length, diagnostic confidence level, and total functional capacity score. Multivariate logistic regression was used to calculate odds ratios adjusted for age, sex, tobacco and alcohol use, depression and psychosis scores, and cognition to compare HD groups to non-HD controls. Cox proportional hazards models and Kaplan Meier curves were used to determine differences in probabilities of developing sleep disturbances and how sleep disturbances are related to age at motor onset.

RESULTS

There were significant differences between HD participants and non-HD controls in both the disease type and disease stage analyses (p < 0.001). The odds of a sleep disturbance increased with worsening disease stage and was highest in those with juvenile HD. The development of a sleep disorder in manifest HD participants was observed to be around the time of disease onset.

CONCLUSIONS

Sleep disturbances are more frequent in HD patients than those without HD. There are also differences based on disease type and stage. This is supplemented by the finding that the onset of sleep disturbances occurs near the time of motor onset of HD.

Association of CAG Repeat Length in the Huntington Gene With Cognitive Performance in Young Adults

OBJECTIVE

To investigate the relationships between CAG repeat length in the huntingtin gene and cognitive performance in participants above and below the disease threshold for Huntington disease (HD), we performed a cross-sectional analysis of the Enroll-HD database.

METHODS

We analyzed data from young, developing adults (≤30 years of age) without a history of depression, apathy, or cognitive deficits. We included participants with and without the gene expansion (CAG ≥36) for HD. All participants had to have a Total Functional Capacity Score of 13, a diagnostic confidence level of zero, and a total motor score of <10 and had to be >28.6 years from their predicted motor onset. We performed regression analyses to investigate the nonlinear relationship between CAG repeat length and various cognitive measures controlling for age, sex, and education level.

RESULTS

There were significant positive relationships between CAG repeat length and the Symbol Digit Modalities, Stroop Color Naming, and Stroop Interference test scores. There were significant negative relationships between CAG repeat length and scores on Parts A and B of the Trails Making Test (p < 0.05), indicating that longer CAG repeat lengths were associated with better performance.

DISCUSSION

An increasing number of CAG repeats in the huntingtin gene below disease threshold and low pathologic CAG ranges were associated with some improvements in cognitive performance. These findings outline the relationship between CAG repeats within the huntingtin gene and cognitive development.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that CAG repeat length is positively associated with cognitive function across a spectrum of CAG repeat lengths.

Autonomic dysregulation as an early pathologic feature of Huntington Disease

OBJECTIVE

Autonomic nervous system (ANS) dysfunction has been described in adults with motor-manifest Huntington's Disease (HD) or those who are near their predicted motor onset. It is unclear if ANS dysfunction is present years prior to the onset of motor symptoms of HD. To bridge this gap in knowledge, we compared crude markers of ANS function between children with the gene-expansion that causes HD (GE group) who were decades from their predicted motor onset and gene-non-expanded children (GNE group).

METHODS

We included participants from the Kids-HD study who were <18 years old. Linear mixed effects regression models were constructed that controlled for sex, age, and BMI, and included a random effect per participant and per family. We compared resting heart rate (rHR), core body temperature (CBT), systolic blood pressure (SBP), and diastolic blood pressure (DBP) between the GE (n = 84) and GNE (n = 238) groups. We then grouped participants from the GE group based on their predicted years to onset (YTO) and compared their vital signs to the GNE group.

RESULTS

The GE group had higher rHR (∆ = 3.83, p = 0.0064), SBP (∆ = 2.38, p = 0.032), and CBT (∆ = 0.16, t = 2.92, p = 0.007). The mean rHR and CBT became significantly elevated compared to the GNE group in participants who had 15-25 YTO and those who had <15 YTO. The mean SBP of participants who had 25-35 YTO was significantly elevated compared to the GNE group.

CONCLUSION

ANS dysfunction in HD seems to occur approximately 20 years prior to the predicted onset of motor symptoms of HD.

Age-Related Cognitive Changes as a Function of CAG Repeat in Child and Adolescent Carriers of Mutant Huntingtin

Limited data exists regarding the disease course of Huntington's Disease (HD) in children and young adults. Here, we evaluate the trajectory of various cognitive skill development as a function of cytosine-adenine-guanine (CAG) repeat length in children and adolescents that carry the mutation that causes HD. We discovered that the development of verbal skills seems to plateau earlier as CAG repeat length increases. These findings increase our understanding of the relationship between neurodegeneration and neurodevelopment and may have far-reaching implications for future gene-therapy treatment strategies. ANN NEUROL 2021;89:1036-1040.

Melatonin may slow disease progression in amyotrophic lateral sclerosis: Findings from the Pooled Resource Open-Access ALS Clinic Trials database

INTRODUCTION

We utilized the Pooled Resource Open-Access Clinical Trials (PRO-ACT) database to investigate whether melatonin use among patients with amyotrophic lateral sclerosis (ALS) was associated with slower disease progression and prolonged survival.

METHODS

This retrospective analysis of the PRO-ACT database addresses the impact of melatonin on progression and overall survival of ALS. A Cox proportional hazards ratio model was performed to investigate the effect that melatonin had on time to death. For secondary outcome measures, linear mixed effects regression models were used to ascertain the effect of melatonin on change in standardized ALS Functional Rating Scale (sALSFRS) and percentage predicted forced vital capacity (FVC) scores.

RESULTS

Melatonin users had a significantly decreased annualized hazard death rate compared with the non-melatonin users (hazard ratio, 0.241; 95% confidence interval, 0.088-0.659; P = .0056). The melatonin users also had a slower rate of decline in sALSFRS score (t = 2.71; P = .0069) and change in percent predicted FVC score (t = 2.94; P = .0035) compared with the non-melatonin users.

DISCUSSION

Our findings suggest that melatonin may be beneficial for patients with ALS. Due to the nature of this database, our results are solely intended to be hypothesis-generating and no strong associations can be made. Given the low cost and favorable safety profile of melatonin, the hypotheses generated warrant further investigation.

Hypertension Is Associated With an Earlier Age of Onset of Huntington's Disease

BACKGROUND AND OBJECTIVE

Hypertension (HTN) is associated with worsening clinical outcomes in neurodegenerative diseases. The relationship between HTN and the age of diagnosis (ADx) of Huntington's disease (HD) is not clear, however. This study sought to determine if the presence of HTN in adult patients with premanifest HD was associated with an earlier ADx compared with normotensive patients with HD.

METHODS

Premanifest participants from Enroll-HD were included if they had a cytosine-adenine-guanine greater than or equal to 36, baseline diagnostic confidence level less than 4, baseline total functional capacity score greater than 11, and baseline motor score less than 21. There were 3020 premanifest participants with HD, and 293 reported a diagnosis of HTN. HTN was transformed into a time-dependent variable, and a Cox proportional hazard survival model determine if the presence of HTN affected the time to motor conversion. Baseline cytosine-adenine-guanine-age product score, cytosine-adenine-guanine repeat length, baseline age, sex, baseline body mass index, smoking history, and region were included as covariates.

RESULTS

Participants with HTN had an increased annualized hazard of motor conversion compared to normotensive participants with HD (hazard ratio, 1.29; 95% confidence interval, 1.02-1.64; P = 0.034).

CONCLUSIONS

A previous study reported a protective effect of HTN in HD, but did not account for the fact that the prevalence of HTN increases with age. By controlling for this confounder, we more accurately outline the association between the ADx of HD to demonstrate that a diagnosis of HTN may be associated with an earlier ADx of HD. These results represent an association, however, and further investigation is warranted. © 2020 International Parkinson and Movement Disorder Society.

The Association between CAG Repeat Length and Age of Onset of Juvenile-Onset Huntington's Disease

There is a known negative association between cytosine-adenine-guanine (CAG) repeat length and the age of motor onset (AMO) in adult-onset Huntington's Disease (AOHD). This relationship is less clear in patients with juvenile-onset Huntington's disease (JOHD), however, given the rarity of this patient population. The aim of this study was to investigate this relationship amongst a relatively large group of patients with JOHD using data from the Kids-JOHD study. Additionally, we analyzed data from the Enroll-HD platform and the Predict-HD study to compare the relationship between CAG repeat length and AMO amongst patients with AOHD to that amongst patients with JOHD using linear regression models. In line with previous reports, the variance in AMO that was predicted by CAG repeat length was 59% (p < 0.0001) in the Predict-HD study and 57% from the Enroll-HD platform (p < 0.0001). However, CAG repeat length predicted 84% of the variance in AMO amongst participants from the Kids-JOHD study (p < 0.0001). These results indicate that there may be a stronger relationship between CAG repeat length and AMO in patients with JOHD as compared to patients with AOHD. These results provide additional information that may help to model disease progression of JOHD, which is beneficial for the planning and implementation of future clinical trials.

Enhancing glycolysis attenuates Parkinson's disease progression in models and clinical databases

Parkinson's disease (PD) is a common neurodegenerative disease that lacks therapies to prevent progressive neurodegeneration. Impaired energy metabolism and reduced ATP levels are common features of PD. Previous studies revealed that terazosin (TZ) enhances the activity of phosphoglycerate kinase 1 (PGK1), thereby stimulating glycolysis and increasing cellular ATP levels. Therefore, we asked whether enhancement of PGK1 activity would change the course of PD. In toxin-induced and genetic PD models in mice, rats, flies, and induced pluripotent stem cells, TZ increased brain ATP levels and slowed or prevented neuron loss. The drug increased dopamine levels and partially restored motor function. Because TZ is prescribed clinically, we also interrogated 2 distinct human databases. We found slower disease progression, decreased PD-related complications, and a reduced frequency of PD diagnoses in individuals taking TZ and related drugs. These findings suggest that enhancing PGK1 activity and increasing glycolysis may slow neurodegeneration in PD.

Abnormal development of cerebellar-striatal circuitry in Huntington disease

OBJECTIVE

To test the hypothesis that the trajectory of functional connections over time of the striatum and the cerebellum differs between presymptomatic patients with the Huntington disease (HD) gene expansion (GE) and patients with a family history of HD but without the GE (GNE), we evaluated functional MRI data from the Kids-HD study.

METHODS

We utilized resting-state, functional MRI data from participants in the Kids-HD study between 6 and 18 years old. Participants were divided into GE (CAG 36-59) and GNE (CAG <36) groups. Seed-to-seed correlations were calculated among 4 regions that provide input signals to the anterior cerebellum: (1) dorsocaudal putamen, (2) globus pallidus externa, (3) subthalamic nucleus, and (4) pontine nuclei; and 2 regions that represented output from the cerebellum: the dentate nucleus to the (1) ventrolateral thalamus and (2) dorsocaudal putamen. Linear mixed effects regression models evaluated differences in developmental trajectories of these connections over time between groups.

RESULTS

Four of the six striatal-cerebellum correlations showed significantly different trajectories between groups. All showed a pattern where in the early age ranges (6-12 years) there was hyperconnectivity in the GE compared to the GNE, with those trajectories showing linear decline in the latter half of the age range.

CONCLUSION

These results parallel previous findings showing striatal hypertrophy in children with GE as early as age 6. These findings support the notion of developmentally higher connectivity between the striatum and cerebellum early in the life of the child with HD GE, possibly setting the stage for cerebellar compensatory mechanisms.

Human Immunodeficiency Virus Infection in Huntington's Disease is Associated with an Earlier Age of Symptom Onset

BACKGROUND

Huntington Disease (HD) and human immunodeficiency virus (HIV) are both associated with neurodegeneration in the cerebral cortex and striatum. The rate of striatal degeneration is a known predictor of symptom onset in HD indicating a potential neurobiological link between HD and HIV.

OBJECTIVE

To determine if the presence of pre-existing HIV infection would trigger a significantly earlier age of symptom onset (ASO) in HD-mutation carriers when compared to non-infected HD subjects.

METHODS

This was a retrospective analysis of the Enroll-HD database that included participants with a CAG repeat of at least 36. Participants with HD and a comorbidity of HIV that was diagnosed prior to their reported ASO were identified and compared to participants with HD who did not have HIV. An ANCOVA analysis was performed to investigate the differences in ASO between the HIV and non-HIV groups. Sex, drug use, and CAG repeat number were used as covariates.

RESULTS

The average ASO of HD subjects with previous HIV infection (n = 8) was 9.1 years earlier than non-HIV infected HD subjects (n = 3259) [F (1, 3267) =10.05, p = 0.002]. Despite low numbers of participants in the HIV group, the calculated effect size of this difference was 1.07.

CONCLUSION

The known neurobiological changes caused by HIV seem to hasten the ASO in patients with HD. These results may enhance our understanding of the neuropathology of HD in a way that will help with the identification of novel targets for future therapies.

Impact of pharmacy services on cystic fibrosis transmembrane conductance regulator modulator prescribing at a pediatric cystic fibrosis center

BACKGROUND

This study was undertaken to determine if the presence of a clinical pharmacy team impacted patients' access to cystic fibrosis transmembrane conductance regulator (CFTR) modulators.

METHODS

A retrospective chart review of electronic medical records from the University of Iowa Hospitals and Clinics (UIHC) was conducted. Data were collected regarding the timing of prior authorization (PA) submissions and approvals from 2012 to 2018. The Wilcoxon rank-sum test was used to compare the meantime (days) between prescription and PA submission dates, and PA submission and approval date for all patients included in the analysis. Comparisons were made for pre- and postpharmacy services eras as well as the UIHC Specialty Pharmacy versus a non-UIHC Specialty Pharmacy.

RESULTS

Sixty-three patients were included in the final analysis. The average time between prescription date and PA submission was 12.5 days (standard deviation [SD] = 17.4 days) in the preclinical pharmacy services era and 3.5 days (SD = 5.8 days; P = .028) in the postclinical pharmacy services era. The average time to PA submission significantly decreased from 9.8 days (SD = 13.1 days) to 1.3 days (SD = 4.2 days; P < .0001) when prescriptions were filled by the UIHC Specialty Pharmacy vs a non-UIHC Specialty Pharmacy.

CONCLUSIONS

There was a significant benefit to CFTR modulator prescribing when clinical pharmacy services were incorporated in our cystic fibrosis (CF) care team, which will become increasingly important with the anticipation of new CF medications in the near future.

Comparing Risperidone and Olanzapine to Tetrabenazine for the Management of Chorea in Huntington Disease: An Analysis from the Enroll-HD Database

INTRODUCTION

Huntington's chorea (HC) is commonly managed with neuroleptic medications, though there is little evidence to support their use. This study aimed to perform a real-world comparison of the efficacy of risperidone and olanzapine to tetrabenazine (TBZ) for HC.

METHODS

The Enroll-HD database was used to perform a propensity score-matched comparison of risperidone and olanzapine to TBZ, regarding their efficacy in controlling chorea. Participants with motor manifest Huntington's disease (HD) were grouped according to their use of risperidone, olanzapine, or TBZ. For the three groups, independent propensity score matching was performed on participants' baseline total functional score (TFC), baseline total motor score (TMS), disease burden score, CAG repeat length, baseline age, region, sex, and body mass index. Independent samples t test was used to calculate the differences between the groups in the annual rate of change of the TMS from the baseline to the second available visit.

RESULTS

The risperidone (n = 72) and olanzapine groups (n = 77) had annualized increases (worsening) in the TMS of only 1.47 points and 3.20 points, respectively, compared to 5.70 points in the two matched TBZ groups (n = 72) (P = 0.019) and (n = 77) (P = 0.143), respectively.

CONCLUSIONS

In the absence of prospective data, this analysis of the Enroll-HD database found that the neuroleptics risperidone and olanzapine seemed to at least be comparable to TBZ at controlling HC. These results demonstrate that neuroleptics may have comparable efficacy to TBZ for the treatment of HC. Further prospective studies are needed to confirm these findings.

Statin use and delayed onset of Huntington's disease

BACKGROUND

There is evidence to suggest that 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase inhibitors (statins) may be beneficial in Huntington's disease (HD).

OBJECTIVE

This study aimed to determine if statin use was associated with delayed motor diagnosis in participants with premotor HD.

METHODS

Among premotor HD participants from the Enroll-HD database, statin users were propensity score matched with statin nonusers based on cytosine-adenine-guanine-age product score, cytosine-adenine-guanine repeat length, baseline age, sex, and region. A Cox regression survival analysis compared the annualized hazard ratio (HR) of receiving a motor diagnosis between the 2 groups.

RESULTS

The annualized HR of progressing to an HD motor diagnosis was lower in the statin users (n = 89) when compared with the statin nonusers (n = 89; HR = 0.27 [95% CI 0.18-0.50], P < .0001).

CONCLUSIONS

In patients with premotor HD, statin use was associated with a delayed motor diagnosis of HD. Further studies are warranted to investigate if statins would be an effective disease-modifying therapy for HD. © 2018 International Parkinson and Movement Disorder Society.

Evaluating depression and suicidality in tetrabenazine users with Huntington disease

OBJECTIVE

To determine whether tetrabenazine (TBZ) use is associated with an increased incidence of depression and/or suicidal ideation.

METHODS

In this retrospective cross-sectional study of the Enroll-HD database, we used multiple logistic regression analyses to determine whether TBZ use is associated with an increased incidence of depression and/or suicidal ideation. For both dependent variables (depression and suicidality), separate analyses were conducted on (1) all participants, (2) only participants with a history of depression, and (3) only participants with no history of depression. Adjustments were made for CAG repeat length, total motor score, total functional capacity, Symbol Digit Modalities Test score, sex, disease duration, history of depression (when applicable), antipsychotic use, and antidepressant use.

RESULTS

Compared to participants who were not using TBZ (n = 3,548), TBZ users (n = 543) did not have an increased risk of depression (odds ratio [OR] = 0.78, p = 0.064). Participants taking TBZ actually had a relatively lower risk of suicidality (OR = 0.61, p = 0.043). Among only participants with a history of depression, those using TBZ had a lower incidence of depression (OR = 0.71, p = 0.016) and suicidal ideation (OR = 0.57, p = 0.028) compared to those not using TBZ. Finally, among only participants with no history of depression, TBZ use was not associated with a higher incidence of depression (OR = 1.59, p = 0.18) or suicidality (OR = 1.43, p = 0.66) compared to those who were not using TBZ.

CONCLUSIONS

TBZ use was not associated with an increased incidence of depression or suicidality. These findings suggest that TBZ may be safe to use in patients with Huntington disease who have a history of depression.

Comparing Clinical Outcomes of a Pharmacist-Managed Diabetes Clinic to Usual Physician-Based Care

BACKGROUND

This study analyzed the impact of a pharmacist-managed diabetes clinic on clinical outcomes compared to usual care received from primary care providers (PCPs). This comparison may more definitively demonstrate the value of pharmacist management of chronic disease states.

METHODS

Retrospective observational cohort study conducted in patients referred to a pharmacist-managed pharmacotherapy (PT) clinic from July 2009 to October 2014.

RESULTS

For the primary outcome, the absolute change in A1c during the usual care phase was +1.53% (95% confidence interval [CI]: 1.10-1.96, P < .0001) versus an absolute change of -1.63% (95% CI: -1.28 to -1.97, P < .0001) in the intervention phase. For secondary outcomes, diabetes-related hospitalizations (10 vs 6, P = .104) and emergency room (ER) visits (27 vs 8, P = .049) decreased in the intervention phase compared to the usual care phase. The rate of diabetes-related interventions made per patient per year in the usual care phase was 2.7 versus 11.1 in the intervention phase ( P < .0001).

CONCLUSION

Patients referred to the PT clinic had worsening blood glucose control prior to referral, and their control improved after referral to the clinic. Furthermore, there was an improvement in all diabetes-related outcomes in the intervention phase compared to the usual care phase.

Substance abuse may hasten motor onset of Huntington disease: Evaluating the Enroll-HD database

OBJECTIVE

To investigate the relationship between substances of abuse and age at motor onset (AMO) in patients with Huntington disease (HD) in a large and diverse patient population.

METHODS

This was a retrospective, observational study of the Enroll-HD database. Participants were determined to belong to 1 of 3 substance abuse groups: (1) tobacco abusers, (2) alcohol abusers, and (3) drug abusers. A group of participants who had never abused substances served as a control group. The average AMO of patients in the substance abuse groups was compared to the control group. The number of CAG repeats was used as a covariate in all analyses.

RESULTS

The average difference in AMOs of participants in the tobacco (n = 566), alcohol (n = 374), and drug abuse groups (n = 217) compared to the control group (n = 692) were 2.3 (F_{1, 1,258} = 33.8, p < 0.0001), 1.0 (F_{1, 1,066} = 4.2, p = 0.04), and 3.3 (F_{1, 909} = 29.7, p < 0.0001) years earlier, respectively. In all substance abuse groups, the AMO was lowered to a greater degree in female participants than it was in male participants.

CONCLUSIONS

Substances of abuse have a strong effect on the AMO in patients with HD. These effects seem to be amplified in women with HD compared to men. These results may provide a safe intervention capable of adding disease-free years to patients with HD.

Antioxidant enzyme levels as a function of growth state in cell culture

Manganese superoxide dismutase (MnSOD) levels were monitored as a function of time in culture to determine whether these levels were altered at logarithmic growth versus when the cells exhibited density limitation of growth. For comparison, activities of the antioxidant enzymes copper, zinc superoxide dismutase (CuZnSOD), catalase, and glutathione peroxidase were also evaluated. Four cell lines were studied, two of which exhibited density limitation of growth and two of which did not. Each cell line showed a unique antioxidant enzyme profile. The two cell lines that showed density limitation of growth also demonstrated induction of MnSOD at the time when the cells stopped proliferating in culture, whereas the other two cell lines did not show induction of MnSOD. There was no strict correlation between density limitation of growth and activities of the other antioxidant enzymes. To determine whether SOD varied with various phases of the cell cycle, NIH/3T3 cells were synchronized using serum starvation, and then SOD activities were measured during quiescence (G0) and the phase of DNA synthesis (S-phase). MnSOD was decreased during S-phase compared with G0, whereas CuZnSOD was increased during S-phase compared with G0, demonstrating alteration of SOD activities with varying phases of the cell cycle. This study suggests the possibility that increased MnSOD may correlate with decreased cell proliferation and suggests significant alterations in SOD activities during the cell cycle.

In vitro modulation of antioxidant enzyme levels in normal hamster kidney and estrogen-induced hamster kidney tumor

Antioxidant enzyme (AE) activities were studied in normal hamster kidney proximal tubules and in estrogen-induced hamster kidney cancer. In vivo, kidney tumor had lower activities of manganese superoxide dismutase (MnSOD), copper, zinc superoxide dismutase, catalase, and glutathione peroxidase than kidney proximal tubules. Differences in AE activities were, in general, maintained in tissue culture, with AE activities remaining low in tumor cells compared to normal cells. Normal proximal tubular cells showed significant induction of MnSOD activity as a function of time in culture or following exposure to diethylstilbestrol, a synthetic estrogen, while MnSOD activity remained low in tumor cells under these conditions. Our results suggest that antioxidant enzymes, particularly MnSOD, are regulated differently in estrogen-induced hamster kidney tumor cells than in normal kidney proximal tubular cells, demonstrating that cancers arising from hormonal influence have similar AE profiles to those previously described in cancers arising from viral or chemical etiologies.

Laryngeal movement, oropharyngeal pressure, and submental muscle contraction during swallowing

This study examined temporal relationships of laryngeal movement, oropharyngeal pressure and submental muscle contraction during swallowing. Techniques used to obtain the temporal measures were electroglottography (EGG), oropharyngeal manometry, and submental surface electromyography. Liquid bolus swallows were performed by 40 normal subjects evenly divided by young and elderly, men and women. Results of this investigation suggest that the EGG waveform is reflective of the temporal aspects of laryngeal movement during swallowing and that the EGG has potential as a behavioral modification technique in swallowing therapy. A case study is presented to illustrate the use of the electroglottograph for biofeedback.

In vitro characterization of estrogen induced Syrian hamster renal tumors: comparison with an immortalized cell line derived from diethylstilbestrol-treated adult hamster kidney

Primary diethylstilbestrol-induced kidney tumors from Syrian hamsters were grown in vitro and maintained in culture for 6 mo. Combined immunohistochemical studies using antibodies to intermediate filaments and ultrastructural studies of tumor cells in culture exhibited characteristics similar to tumor cells in vivo. Furthermore, the cells manifested transformed properties in culture; they grew both as multilayered colonies attached to the tissue culture substrate and as floating multicellular colonies (spheroids). When cultured cells were injected into diethylstilbestrol-treated recipient hamsters, tumors developed at the injection sites. In contrast, renal tubules or whole kidney cortex from control hamsters cultured in the same medium underwent only short-term growth, with senescence developing after approximately 1 mo. However, cell cultures of kidney cortex from animals treated in vivo for 5 mo. with diethylstilbestrol formed a cell line. This diethylstilbestrol-induced cell line has been maintained in culture for 1.5 yr and has the following characteristics: a) it is anchorage-dependent, b) it is negative in in vivo tumorigenicity tests, and c) cultured cells are histochemically and ultrastructurally similar to cultured tumor cells. This culture system should prove to be of use in studying hormonal carcinogenesis in vitro.

Antioxidant enzymes and steroid-induced proliferation of kidney tubular cells

Diethylstilbestrol induces proliferation of Syrian hamster renal proximal tubular cells. By counting the number of cells in culture, we showed that liposomes containing superoxide dismutase or catalase suppressed diethylstilbestrol-induced proliferation, whereas empty liposomes or liposomes containing inactivated superoxide dismutase did not. Liposomes containing antioxidant enzymes did not suppress proliferation of cells in control media or of cells treated with ethinyl estradiol. In the absence of liposomes, exogenous superoxide dismutase did not suppress diethylstilbestrol-induced proliferation. The decrease in cell number when diethylstilbestrol-treated cells were treated with antioxidant enzyme-containing liposomes was not due to decreased cell viability. Results were confirmed by measuring a correlate of cell proliferation immunohistochemically, using an antibody to proliferating cell nuclear antigen. A larger proportion of diethylstilbestrol-treated cells than of control cells showed nuclear immunostaining with this antibody. The number of cells immunostained in diethylstilbestrol-treated cultures was sharply decreased by the addition of superoxide dismutase- or catalase-containing liposomes. Our studies suggest a role for active oxygen species in diethylstilbestrol-induced proliferation of cultured proximal tubular cells.