Autonomic disorders and myocardial 123I-metaiodobenzylguanidine scintigraphy in Huntington's disease

Systemic Symptoms in Huntington's Disease: A Comprehensive Review

BACKGROUND

Although Huntington's disease (HD) is usually thought of as a triad of motor, cognitive, and psychiatric symptoms, there is growing appreciation of HD as a systemic illness affecting the entire body.

OBJECTIVES

This review aims to draw attention to these systemic non-motor symptoms in HD.

METHODS

We identified relevant studies published in English by searching MEDLINE (from 1966 to September 2023), using the following subject headings: Huntington disease, autonomic, systemic, cardiovascular, respiratory, gastrointestinal, urinary, sexual and cutaneous, and additional specific symptoms.

RESULTS

Data from 123 articles were critically reviewed with focus on systemic features associated with HD, such as cardiovascular, respiratory, gastrointestinal, urinary, sexual and sweating.

CONCLUSION

This systematic review draws attention to a variety of systemic and autonomic co-morbidities in patients with HD. Not all of them correlate with the severity of the primary HD symptoms or CAG repeats. More research is needed to better understand the pathophysiology and treatment of systemic and autonomic dysfunction in HD.

Review of cardiovascular imaging in the Journal of Nuclear Cardiology 2022: single photon emission computed tomography

In this review, we will summarize a selection of articles on single-photon emission computed tomography published in the Journal of Nuclear Cardiology in 2022. The aim of this review is to concisely recap major advancements in the field to provide the reader a glimpse of the research published in the journal over the last year. This review will place emphasis on myocardial perfusion imaging using single-photon emission computed tomography summarizing advances in the field including in prognosis, non-perfusion variables, attenuation compensation, machine learning and camera design. It will also review nuclear imaging advances in amyloidosis, left ventricular mechanical dyssynchrony, cardiac innervation, and lung perfusion. We encourage interested readers to go back to the original articles, and editorials, for a comprehensive read as necessary but hope that this yearly review will be helpful in reminding readers of articles they have seen and attracting their attentions to ones they have missed.

Cardiac sympathetic innervation and mortality risk scores in patients with heart failure

INTRODUCTION

In the risk stratification and selection of patients with heart failure (HF) eligible for implantable cardioverter-defibrillator (ICD) therapy, ¹²³ I-meta-IodineBenzylGuanidine (¹²³ I-mIBG) scintigraphy has emerged as an effective non-invasive method to assess cardiac adrenergic innervation. Similarly, clinical risk scores have been proposed to identify patients with HF at risk of all-cause mortality, for whom the net clinical benefit of device implantation would presumably be lower. Nevertheless, the association between the two classes of tools, one suggestive of arrhythmic risk, the other of all-cause mortality, needs further investigation.

OBJECTIVE

To test the relationship between the risk scores for predicting mortality and cardiac sympathetic innervation, assessed through myocardial ¹²³ I-mIBG imaging, in a population of patients with HF.

METHODS

In HF patients undergoing ¹²³ I-mIBG scintigraphy, eight risk stratification models were assessed: AAACC, FADES, MADIT, MADIT-ICD non-arrhythmic mortality score, PACE, Parkash, SHOCKED and Sjoblom. Cardiac adrenergic impairment was assessed by late heart-to-mediastinum ratio (H/M) <1.6.

RESULTS

Among 269 patients suffering from HF, late H/M showed significant negative correlation with all the predicting models, although generally weak, ranging from -0.15 (p = .013) for PACE to -0.32 (p < .001) for FADES. The scores showed poor discrimination for cardiac innervation, with areas under the curve (AUC) ranging from 0.546 for Parkash to 0.621 for FADES.

CONCLUSION

A weak association emerged among mortality risk scores and cardiac innervation, suggesting to integrate in clinical practice tools indicative of both arrhythmic and general mortality risks, when evaluating patients affected by HF eligible for device implantation.

Genetic and clinical analysis of TP73 gene in amyotrophic lateral sclerosis patients from Chinese mainland

Introduction

TP73 was recently identified as a novel causative gene for amyotrophic lateral sclerosis (ALS). We aimed to determine the contribution of variations in TP73 in the Chinese ALS population and to further explore the genotype-phenotype correlations.

Methods

We screened rare, putative pathogenic TP73 mutations in a large Chinese ALS cohort and performed association analysis of both rare and common TP73 variations between cases and controls.

Results

Of the 985 ALS patients studied, six rare, heterozygous putative pathogenic variants in TP73 were identified among six unrelated sALS patients. Exon 14 of TP73 might be a mutant hotspot in our cohort. Patients with ALS with only rare, putative pathogenic TP73 mutations exhibited a characteristic clinical profile. Patients harboring multiple mutations in TP73 and other ALS-related genes displayed a significantly earlier onset of ALS. Association analysis revealed that rare TP73 variants in the untranslated regions (UTRs) were enriched among ALS patients; meanwhile, two common variants in the exon-intron boundary were discovered to be associated with ALS.

Discussion

We demonstrate that TP73 variations also have contributed to ALS in the Asian population and broaden the genotypic and phenotypic spectrum of TP73 variants in the ALS-frontotemporal dementia (FTD) spectrum. Furthermore, our findings first suggest that TP73 is not only a causative gene, but also exerts a disease-modifying effect. These results may contribute to a better understanding of the molecular mechanism of ALS.

40 Years Anniversary of Cardiac 123I-mIBG Imaging: State of the Heart

Purpose of Review

This narrative review reflects on the body of evidence on cardiac 123I-mIBG imaging that has accumulated since the introduction in the late 1970s and focusses on to what extent cardiac 123I-mIBG imaging has fulfilled its potential in cardiology especially.

Recent Findings

In contrast to the linear relationship between 123I-mIBG-derived parameters and overall prognosis in heart failure, there seems a “bell-shape” curve for 123I-mIBG-derived parameters and arrhythmic events. In addition, there is a potential clinical role for cardiac 123I-mIBG in optimizing patient selection for expensive devices (i.e., ICD and CRT). This needs of course to be established in future trials.

Summary

Cardiac 123I-mIBG imaging is, despite the numerous of studies, sometimes mistakenly seen as a nice to have technique rather than a must have imaging modality. Although cardiac 123I-mIBG imaging has grown and matured over the years, its full clinical potential has still not been tested to the maximum.

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.