Paradoxical physiological responses to propranolol in a Rett syndrome patient: a case report

Acute Cardiovascular and Cardiorespiratory Effects of JWH-018 in Awake and Freely Moving Mice: Mechanism of Action and Possible Antidotal Interventions?

JWH-018 is the most known compound among synthetic cannabinoids (SCs) used for their psychoactive effects. SCs-based products are responsible for several intoxications in humans. Cardiac toxicity is among the main side effects observed in emergency departments: SCs intake induces harmful effects such as hypertension, tachycardia, chest pain, arrhythmias, myocardial infarction, breathing impairment, and dyspnea. This study aims to investigate how cardio-respiratory and vascular JWH-018 (6 mg/kg) responses can be modulated by antidotes already in clinical use. The tested antidotes are amiodarone (5 mg/kg), atropine (5 mg/kg), nifedipine (1 mg/kg), and propranolol (2 mg/kg). The detection of heart rate, breath rate, arterial oxygen saturation (SpO2), and pulse distention are provided by a non-invasive apparatus (Mouse Ox Plus) in awake and freely moving CD-1 male mice. Tachyarrhythmia events are also evaluated. Results show that while all tested antidotes reduce tachycardia and tachyarrhythmic events and improve breathing functions, only atropine completely reverts the heart rate and pulse distension. These data may suggest that cardiorespiratory mechanisms of JWH-018-induced tachyarrhythmia involve sympathetic, cholinergic, and ion channel modulation. Current findings also provide valuable impetus to identify potential antidotal intervention to support physicians in the treatment of intoxicated patients in emergency clinical settings.

Emotional Behavioural and Autonomic Dysregulation (EBAD) in Rett Syndrome - EDA and HRV monitoring using wearable sensor technology

BACKGROUND

Rett syndrome (RTT) is a severe genetic neurodevelopmental disorder. Emotional, Behavioural and Autonomic Dysregulation (EBAD), is frequent in RTT and is associated with multiple impairments. There are major challenges in the clinical assessment of emotions, behaviours, and autonomic function in RTT patients that limit the management of symptoms.

METHODS

Web-based technology (HealthTracker™) to measure the phenotype, and non-invasive, wearable sensor technology to evaluate autonomic function through Electrodermal Activity (EDA) and Heart Rate Variability (HRV) in 10 RTT patients was used, and treatment response of EBAD symptoms was monitored after different pharmacological treatments.

RESULTS

and discussion: 4 patients received buspirone, 2 sertraline, 1 gabapentin and 3 were not started on medications. Buspirone normalized the EDA in 3 patients with associated improvement in EBAD, whilst another patient only improved marginally. Both patients treated with sertraline (including one with normal EDA) significantly improved symptomatically. The patients on unchanged regimens showed no change in symptoms and autonomic function. Within 24 h of our assessment, one patient required intensive inpatient care due to septicaemia - this patient had been on gabapentin and showed a sharp and sustained EDA increase without obvious worsening of emotional and behavioural symptoms. Unlike the EDA, the analyses of HRV metrics did not reveal patterns that were associated with clinical outcomes. Our findings suggest a reasonable association of EDA normalization and symptomatic improvement in RTT subjects with EBAD treated with buspirone and point out its potential application as a measure of dysautonomia in RTT. Very high and sustained EDA levels may be a biomarker for concurrent serious physical illness in RTT.

Autonomic Characteristics of Sudden Unexpected Death in Epilepsy in Children-A Systematic Review of Studies and Their Relevance to the Management of Epilepsy in Rett Syndrome

Aim: To systematically identify and critically appraise studies that investigate the autonomic characteristics of Sudden Unexpected Death in Epilepsy (SUDEP) in the pediatric population. We also wanted to explore how this information would be relevant to the management of epilepsy in patients with Rett Syndrome.

Method: Using PRISMA guidelines, a systematic review of PubMed, Scopus, Cochrane, PsycINFO, Embase, and Web of Science databases was performed to identify eligible studies. After extracting data from the included studies, a thematic analysis was undertaken to identify emerging themes. A quality appraisal was also done to assess the quality of the included studies.

Results: The systematic search revealed 41 records, and 15 full-text articles on the autonomic characteristics of SUDEP in children were included in the final analysis. Following thematic analysis, three themes were identified (I) modulation in sympathovagal tone, (II) pre- and post-ictal autonomic changes, and (III) other markers of autonomic dysregulation in children with epilepsy. Modulation in sympathovagal tone emerged as the theme with the highest frequency followed by pre- and post-ictal autonomic changes. While the themes provide additional insight into the management of epilepsy in the Rett Syndrome population, the quality of evidence concerning the autonomic characteristics of SUDEP in the pediatric population was low and underscores the importance of much needed research in this area.

Conclusion: The mechanism of SUDEP in the pediatric population is complex and involves an interplay between several components of the autonomic nervous system. While direct clinical inferences regarding pediatric SUDEP could not be made, the thematic analysis does suggest that in vulnerable populations such as Rett Syndrome, where there is already a pervasive autonomic dysregulation, pro-active surveillance of the autonomic profile in this patient group would be useful to better manage epilepsy and reduce the SUDEP risk.

Differentiating Females with Rett Syndrome and Those with Multi-Comorbid Autism Spectrum Disorder Using Physiological Biomarkers: A Novel Approach

This study explored the use of wearable sensor technology to investigate autonomic function in children with autism spectrum disorder (ASD) and Rett syndrome (RTT). We aimed to identify autonomic biomarkers that can correctly differentiate females with ASD and Rett Syndrome using an innovative methodology that applies machine learning approaches. Our findings suggest that we can predict (95%) the status of ASD/Rett. We conclude that physiological biomarkers may be able to assist in the differentiation between patients with RTT and ASD and could allow the development of timely therapeutic strategies.

Autonomic dysfunction and sudden death in patients with Rett syndrome: a systematic review

BACKGROUND

Rett syndrome (RTT), a debilitating neuropsychiatric disorder that begins in early childhood, is characterized by impairments in the autonomic nervous system that can lead to sudden unexpected death. This study explores the mechanisms of autonomic dysfunction to identify potential risk factors for sudden death in patients with RTT.

METHODS

Following the Reporting Items for Systematic Review and Meta-Analyses (PRISMA) criteria, we undertook comprehensive systematic reviews using the PubMed, Scopus, Cochrane, PsycINFO, Embase and Web of Science databases.

RESULTS

We identified and critically appraised 39 articles for autonomic dysfunction and 5 for sudden death that satisfied the eligibility criteria. Following thematic analysis, we identified 7 themes: breathing irregularities, abnormal spontaneous brainstem activations, heart rate variability metrics, QTc changes, vagal imbalance, fluctuation in peptides and serotonergic neurotransmission. We grouped these 7 themes into 3 final themes: (A) brainstem modulation of breathing, (B) electrical instability of the cardiovascular system and (C) neurochemical changes contributing to autonomic decline. We described key evidence relating to each theme and identified important areas that could improve the clinical management of patients with RTT.

LIMITATIONS

The heterogeneity of the methods used to assess autonomic function increased the difficulty of making inferences from the different studies.

CONCLUSION

This study identified the important mediators of autonomic dysfunction and sudden death in patients with RTT. We proposed brainstem mechanisms and emphasized risk factors that increase brainstem vulnerability. We discussed clinical management to reduce sudden death and future directions for this vulnerable population.

Interleukin-6, tumor necrosis factor-α, C-reactive protein, and hematological parameters in experimental periodontal disease after β-adrenergic blockade

BACKGROUND

Changes in the levels of C-reactive protein (CRP), tumor necrosis factor α (TNF-α), and interleukin 6 (IL-6) observed during periodontal disease were linked with vascular manifestations. Recent studies showed that the beta-blocker propranolol reduces the pathological parameters associated with certain molecules at sites of bone injury. Hence, in this study, we evaluated the activity of propranolol on hematological parameters and systemic concentrations of inflammatory proteins in a model of experimental periodontitis.

MATERIALS AND METHODS

Periodontal disease was induced in rats. After euthanasia, the number of inflammatory cells in each rat was quantified using histopathological assays. In addition, hematological parameters were quantitated using automated analysers, cytokine levels were determined using an enzyme-linked immunosorbent assay, and CRP levels were determined using a high-sensitivity immunoturbidimetric assay.

RESULTS

Low doses of propranolol suppressed the systemic production of CRP, TNF-α, and IL-6; however, the hematological parameters were not affected.

CONCLUSIONS

β-adrenergic activation indirectly contributes to the pattern of systemic inflammatory molecules observed in periodontal disease. These molecules may initiate cardiovascular diseases as a consequence of periodontitis.

Key issues in Rett syndrome: emotional, behavioural and autonomic dysregulation (EBAD) - a target for clinical trials

Complex neurodevelopmental disorders need multi-disciplinary treatment approaches for optimal care. The clinical effectiveness of treatments is limited in patients with rare genetic syndromes with multisystem morbidity. Emotional and behavioural dysregulation is common across many neurodevelopmental disorders. It can manifest in children across multiple diagnostic groups, including those on the autism spectrum and in rare genetic syndromes such as Rett Syndrome (RTT). There is, however a remarkable scarcity in the literature on the impact of the autonomic component on emotional and behavioural regulation in these disorders, and on the longer-term outcomes on disorder burden.RTT is a debilitating and often life-threatening disorder involving multiple overlapping physiological systems. Autonomic dysregulation otherwise known as dysautonomia is a cardinal feature of RTT characterised by an imbalance between the sympathetic and parasympathetic arms of the autonomic nervous system. Unlocking the autonomic component of emotional and behavioural dysregulation would be central in reducing the impairment seen in patients with RTT. In this vein, Emotional, Behavioural and Autonomic Dysregulation (EBAD) would be a useful construct to target for treatment which could mitigate burden and improve the quality of life of patients.RTT can be considered as a congenital dysautonomia and because EBAD can give rise to impairments occurring in multiple overlapping physiological systems, understanding these physiological responses arising out of EBAD would be a critical part to consider when planning treatment strategies and improving clinical outcomes in these patients. Biometric guided pharmacological and bio-feedback therapy for the behavioural and emotional aspects of the disorder offers an attracting perspective to manage EBAD in these patients. This can also allow for the stratification of patients into clinical trials and could ultimately help streamline the patient care pathway for optimal outcomes.The objectives of this review are to emphasise the key issues relating to the management of EBAD in patients with RTT, appraise clinical trials done in RTT from the perspective of autonomic physiology and to discuss the potential of EBAD as a target for clinical trials.

Development of the Tailored Rett Intervention and Assessment Longitudinal (TRIAL) database and the Rett Evaluation of Symptoms and Treatments (REST) Questionnaire

INTRODUCTION

Rett syndrome (RTT) is a pervasive neurodevelopmental disorder that presents with deficits in brain functioning leading to language and learning regression, characteristic hand stereotypies and developmental delay. Different mutations in the gene implicated in RTT-methyl-CpG-binding protein 2 (MECP2) establishes RTT as a disorder with divergent symptomatology ranging from individuals with severe to milder phenotypes. A reliable and single multidimensional questionnaire is needed that can embrace all symptoms, and the relationships between them, and can map clinically meaningful data to symptomatology across the lifespan in patients with RTT. As part of the HealthTracker-based Tailored Rett Intervention and Assessment Longitudinal (TRIAL) database, the Rett Evaluation of Symptoms and Treatments (REST) Questionnaire will be able to marry with the physiological aspects of the disease obtained using wearable sensor technology, along with genetic and psychosocial data to stratify patients. Taken together, the web-based TRIAL database will empower clinicians and researchers with the confidence to delineate between different aspects of disorder symptomatology to streamline care pathways for individuals or for those patients entering clinical trials. This protocol describes the anticipated development of the REST questionnaire and the TRIAL database which links with the outcomes of the wearable sensor technology, and will serve as a barometer for longitudinal patient monitoring in patients with RTT.

METHODS AND ANALYSIS

The US Food and Drug Administration Guidance for Patient-Reported Outcome Measures will be used as a template to inform the methodology of the study. It will follow an iterative framework that will include item/concept identification, item/concept elicitation in parent/carer-mediated focus groups, expert clinician feedback, web-based presentation of questionnaires, initial scale development, instrument refinement and instrument validation.

ETHICS AND DISSEMINATION

The study has received favourable opinion from the National Health Service (NHS) Research Ethics Committee (REC): NHS Research Ethics Committee (REC)-London, Bromley Research Ethics Committee (reference: 15/LO/1772).