The Association of Nocturnal Seizures and Interictal Cardiac/Central Autonomic Function in Frontal Lobe Epilepsy: Heart Rate Variability and Central Autonomic Network Analysis

Purpose

Patients with epilepsy frequently experience autonomic dysfunction, closely related to sudden unexplained death in epilepsy (SUDEP). SUDEP occurs most often at night or during sleep, and frequent nocturnal seizures are an established risk factor. This study investigated the influence of nocturnal seizures on autonomic dysfunction in epilepsy.

Patients and Methods

This retrospective study enrolled frontal lobe epilepsy (FLE) patients who performed 24-hour EEG monitoring. All participants were divided into nocturnal FLE (NFLE, > 90% of seizures occurring during sleep) or diurnal FLE (DFLE) groups. EEG and ECG signals were simultaneously obtained during waking and sleep stages. EEG current density source and connectivity analysis of the autonomic network were performed. ECG was analyzed across time and frequency domains heart rate variability (HRV) analysis method was used. The obtained parameters were compared between the NFLE and DFLE groups.

Results

Fifteen NFLE and 16 DFLE patients were enrolled with no significant difference in age, sex, disease duration, seizure frequency, or the number of anti-seizure medications between the two groups. During sleep, a decrease in HRV parameters and an increase of the beta-1 (13-22 Hz) current source density power in the bilateral paracentral lobule (BA4,5,6), precuneus (BA7), and cingulate (BA31) were observed in the NFLE group compared to DFLE group. The NFLE group also showed hyperconnectivity in the central autonomic (12 edges distributed over 10 nodes), sympathetic (2 edges distributed over 3 nodes), and parasympathetic (4 edges distributed over 6 nodes) beta-1 frequency band networks during sleep. During wakefulness, central and cardiac autonomic variables were not significantly different between the NFLE and DFLE groups.

Conclusion

Interictal cardiac and central autonomic dysfunction occurred simultaneously and can be attributed to the brain-heart autonomic axis. Our findings suggest that nocturnal seizures may contribute to interictal autonomic dysfunction during sleep in people with epilepsy.

Structural and Functional Brain Changes in Acute Takotsubo Syndrome

BACKGROUND

Takotsubo syndrome mimics an acute myocardial infarction, typically in the aftermath of mental or physical stress.

OBJECTIVES

The mechanism by which emotional processing in the context of stress leads to significant cardiac injury is poorly understood, so a full exploration of brain structure and function in takotsubo syndrome patients merits investigation.

METHODS

Twenty-five acute (<5 days) takotsubo patients and 25 control subjects were recruited into this observational cross-sectional study. Surface-based morphometry was carried out on magnetic resonance imaging (MRI) brain scans to extract cortical morphology based on volume, thickness, and surface area with the use of Freesurfer. Cortical morphology general linear models were corrected for age, sex, photoperiod, and total brain volume. Resting-state functional MRI and diffusion tensor tractography images were preprocessed and analyzed with the use of the Functional Magnetic Resonance Imaging of the Brain Diffusion Toolbox and Functional Connectivity Toolbox.

RESULTS

There was significantly smaller total white matter and subcortical gray matter volumes in takotsubo (P < 0.001), with smaller total brain surface area but increased total cortical thickness (both P < 0.001). Individual gray matter regions (hippocampus and others) were significantly smaller in takotsubo (P < 0.001); only thalamus and insula were larger (P < 0.001). There was significant hyperfunctional and hypofunctional connectivity in multiple areas, including thalamus-amygdala-insula and basal ganglia (P < 0.05). All structural tractography connections were increased in takotsubo (P < 0.05).

CONCLUSIONS

The authors showed smaller gray and white matter volumes driven by smaller cortical surface area, but increased cortical thickness and structural tractography connections with bidirectional changes in functional connectivity linked to emotion, language, reasoning, perception, and autonomic control. These are interventional targets in takotsubo patients' rehabilitation.

Global reports of takotsubo (stress) cardiomyopathy following COVID-19 vaccination: A systematic review and meta-analysis

Concerns have been raised recently about takotsubo cardiomyopathy (TCM) after receiving COVID-19 vaccines, particularly the messenger RNA (mRNA) vaccines. The goal of this study was to compile case reports to provide a comprehensive overview of takotsubo cardiomyopathy (TCM) associated with COVID-19 vaccines. A systematic literature search was conducted in PubMed, Scopus, Embase, Web of Science, and Google Scholar between 2020 and June 1, 2022. The study included individuals who developed cardiac takotsubo cardiomyopathy from receiving COVID-19 vaccinations. Ten studies, including 10 cases, participated in the current systematic review. The mean age was 61.8 years; 90 % were female, while 10 % were male. 80 % of the patients received the mRNA COVID-19 vaccine, while 20 % received other types. In addition, takotsubo cardiomyopathy (TCM) occurred in 50 % of patients receiving the first dose and another 40 % after the second dose of COVID-19 vaccines. Moreover, the mean number of days to the onset of symptoms was 2.62 days. All cases had an elevated troponin test and abnormal ECG findings. The left ventricular ejection fraction (LVEF) was lower than 50 % in 90 % of patients. In terms of the average length of hospital stay, 50 % stayed for 10.2 days, and all cases recovered from their symptoms. In conclusion, takotsubo (stress) cardiomyopathy (TCM) complications associated with COVID-19 vaccination are rare but can be life-threatening. Chest pain should be considered an alarming symptom, especially in those who have received the first and second doses of the COVID-19 vaccine.

Limbic Responses to Aversive Visual Stimuli during the Acute and Recovery Phase of Takotsubo Syndrome

The role of the limbic system in the acute phase and during the recovery of takotsubo syndrome needs further clarification. In this longitudinal study, anatomical and task-based functional magnetic resonance imaging of the brain was performed during an emotional picture paradigm in 19 postmenopausal female takotsubo syndrome patients in the acute and recovery phases in comparison to sex- and aged-matched 15 healthy controls and 15 patients presenting with myocardial infarction. Statistical analyses were performed based on the general linear model where aversive and positive picture conditions were included in order to reveal group differences during encoding of aversive versus positive pictures and longitudinal changes. In the acute phase, takotsubo syndrome patients showed a lower response in regions involved in affective and cognitive emotional processes (e.g., insula, thalamus, frontal cortex, inferior frontal gyrus) while viewing aversive versus positive pictures compared to healthy controls and patients presenting with myocardial infarction. In the recovery phase, the response in these brain regions normalized in takotsubo syndrome patients to the level of healthy controls, whereas patients 8–12 weeks after myocardial infarction showed lower responses in the limbic regions (mainly in the insula, frontal regions, thalamus, and inferior frontal gyrus) compared to healthy controls and takotsubo syndrome patients. In conclusion, compared to healthy controls and patients suffering from acute myocardial infarction, limbic responses to aversive visual stimuli are attenuated during the acute phase of takotsubo syndrome, recovering within three months. Reduced functional brain responses in the recovery phase after a myocardial infarction need further investigation.

Update of Takotsubo cardiomyopathy: Present experience and outlook for the future

Takotsubo cardiomyopathy (TTS) has become a recognised clinical entity since the Japanese scientist Sato first described it in 1990.

Despite an increasing number of confirmed cases, especially during the COVID-19 pandemic, its pathophysiology remains incompletely understood, and decision-making differs in the diagnosis and treatment. In addition, it is not evident whether a significant increase in TTS is due to better understanding among practitioners and widespread access to coronary angiography, or if it is a reflection of an actual increase in incidence.

We analysed a series of international research studies from 1990 to 2021. Beyond epidemiology and clinical presentation, we evaluated and summarised fundamental knowledge about various predisposing factors, with particular attention to the iatrogenic impact of certain drugs, namely antidepressants, chemotherapy, and antiarrhythmics.

Furthermore, we highlighted the main pathophysiological theories to date. In addition, based on published studies and clinical cases, we investigated the role of numerous diagnostic approaches in the differential diagnosis of TTS and identified predictors of TTS complications, such as cardiogenic shock, ventricular fibrillation, and left ventricular thrombi. Accordingly, we sought to propose a diagnostic algorithm and further treatment management of TTS under the presence of possible complications to help practitioners make more informed decisions, as the initial presentation continues to pose a challenge due to its close similarity to acute coronary syndrome with ST-elevation.

In conclusion, this article examines Takotsubo cardiomyopathy from different perspectives and, along with future systematic reviews and meta-analyses, can be of particular interest to practising cardiologists and researchers in developing clinical guidelines.

The role of central autonomic nervous system dysfunction in Takotsubo syndrome: a systematic review

Introduction

Takotsubo syndrome (TTS), also known as stress cardiomyopathy or “broken heart” syndrome, is a mysterious condition that often mimics an acute myocardial infarction. Both are characterized by left ventricular systolic dysfunction. However, this dysfunction is reversible in the majority of TTS patients.

Purpose

Recent studies surprisingly demonstrated that TTS, initially perceived as a benign condition, has a long-term prognosis akin to myocardial infarction. Therefore, the health consequences and societal impact of TTS are not trivial. The pathophysiological mechanisms of TTS are not yet completely understood. In the last decade, attention has been increasingly focused on the putative role of the central nervous system in the pathogenesis of TTS.

Conclusion

In this review, we aim to summarize the state of the art in the field of the brain–heart axis, regional structural and functional brain abnormalities, and connectivity aberrancies in TTS.

Pathophysiology of Takotsubo syndrome - a joint scientific statement from the Heart Failure Association Takotsubo Syndrome Study Group and Myocardial Function Working Group of the European Society of Cardiology - Part 2: vascular pathophysiology, gender and sex hormones, genetics, chronic cardiovascular problems and clinical implications

While the first part of the scientific statement on the pathophysiology of Takotsubo syndrome was focused on catecholamines and the sympathetic nervous system, in the second part we focus on the vascular pathophysiology including coronary and systemic vascular responses, the role of the central and peripheral nervous systems during the acute phase and abnormalities in the subacute phase, the gender differences and integrated effects of sex hormones, genetics of Takotsubo syndrome including insights from microRNA studies and inducible pluripotent stem cell models of Takotsubo syndrome. We then discuss the chronic abnormalities of cardiovascular physiology in survivors, the limitations of current clinical and preclinical studies, the implications of the knowledge of pathophysiology for clinical management and future perspectives and directions of research.

Role of the central autonomic nervous system intrinsic functional organisation and psychosocial factors in primary microvascular angina and Takotsubo syndrome

Introduction and objective

Dysfunctional central autonomic nervous system network (CAN) at rest may result in aberrant autonomic responses to psychosocial stressors. We hypothesised that patients with primary microvascular angina (MVA) or Takotsubo syndrome (TTS) would exhibit a peculiar functional organisation of the CAN, potentially associated with psychological patterns.

Methods

Patients underwent a psychosocial evaluation: a clinical diagnostic interview, Millon Clinical Multiaxial Inventory III, State-Trait Anxiety Inventory form Y and Short Form 36 Health Survey (SF-36). The strength of intrinsic functional connectivity (FC) between various nodes of the CAN was investigated using cerebral resting state functional MRI (RS-fMRI).

Results

We evaluated 50 (46 women) stable patients: 16 patients with MVA, 17 patients with TTS and 17 patients with previous acute myocardial infarction (AMI). Compared with AMI, patients with MVA showed a lower (higher impairment) SF-36 Body-Pain score (p 0.046) and a higher SF-36 Mental-Health score (p 0.039). Patients with TTS showed the strongest FC between two nodes of the CAN (sympathetic midcingulate cortex and parasympathetic primary motor area) (F 6.25, p 0.005) using RS-fMRI.

Conclusions

The study implements an innovative collaborative research among cardiologists, neuroscientists and psychiatrists (‘Neuro-psycho-heart Team’). MVA showed a discrepancy between the highest level of self-reported body pain and the best mental health score, which might suggest a mechanism of somatisation. TTS exhibited an increased functional integration between two areas of the CAN involved in interoceptive pain awareness and negative emotional status. We implemented an innovative research collaboration among cardiologists, neuroscientists and psychiatrists. These data are hypothesis generating and suggest potential prospective investigations on pathophysiology and implementation of psychotherapy and stress-reducing techniques as therapeutic strategies.

Trial registration number

NCT02759341.

Functional neuroimaging in the acute phase of Takotsubo syndrome: volumetric and functional changes of the right insular cortex

Background

A brain–heart interaction has been proposed in Takotsubo syndrome (TTS). Structural changes in the limbic system and hypoconnectivity between certain brain areas in the chronic phase of the disease have been reported, but little is known concerning functional neuroimaging in the acute phase. We hypothesized anatomical and functional changes in the central nervous system and investigated whole-brain volumetric and functional connectivity alterations in the acute phase TTS patients compared to controls.

Methods

Anatomical and resting-state functional magnetic resonance imaging were performed in postmenopausal females: thirteen in the acute TTS phase and thirteen healthy controls without evidence of coronary artery disease. Voxel-based morphometry and graph theoretical analysis were applied to identify anatomical and functional differences between patients and controls.

Results

Significantly lower gray matter volumes were found in TTS patients in the right middle frontal gyrus (p = 0.004) and right subcallosal cortex (p = 0.009) compared to healthy controls. When lower threshold was applied, volumetric changes were noted in the right insular cortex (p = 0.0113), the right paracingulate cortex (p = 0.012), left amygdala (p = 0.018), left central opercular cortex (p = 0.017), right (p = 0.013) and left thalamus (p = 0.017), and left cerebral cortex (p = 0.017). Graph analysis revealed significantly (p < 0.01) lower functional connectivity in TTS patients compared to healthy controls, particularly in the connections originating from the right insular cortex, temporal lobes, and precuneus.

Conclusion

In the acute phase of TTS volumetric changes in frontal regions and the central autonomic network (i.e. insula, anterior cingulate cortex, and amygdala) were noted. In particular, the right insula, associated with sympathetic autonomic tone, had both volumetric and functional changes.

Graphic abstract

Takotsubo syndrome: How the broken heart deals with negative emotions

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Takotsubo patients show lower bilateral superior parietal activity during the processing of negative expected pictures compared to healthy control subjects.

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Takotsubo patients show lower decoding of negative versus neutral pictures in a widespread network consisting of frontal, parietal, occipital, and cerebellar brain regions.

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The lower involvement of brain regions observed in Takotsubo patients suggests an impairment in emotional regulation, which might be of etiological importance in this brain-heart disease.

Objectives

Patients suffering from Takotsubo syndrome have a higher prevalence of anxiety and depressive disorders compared to those with acute myocardial infarction and might thus show impaired regulation and processing of emotions.

Methods

In this cross-sectional study, neural activity during an emotional picture processing task was examined in 26 Takotsubo patients (on average 27 months after the Takotsubo event) and 22 healthy age- and gender-matched control subjects undergoing functional magnetic resonance imaging. Imaging data were analyzed with two complementary approaches: First, univariate analysis was used to detect brain regions showing condition-specific differences in mean neural activity between groups. Second, multivariate pattern analysis was applied to decode the experimental conditions from individual activity patterns.

Results

In the univariate analysis approach, patients showed lower bilateral superior parietal activity during the processing of negative expected pictures compared to the control subjects. The multivariate pattern analysis revealed group differences in decoding negative versus neutral pictures from a widespread network consisting of frontal, parietal, occipital, and cerebellar brain regions. Additionally, differences in decoding the expectation of a negative versus positive upcoming picture were observed in the visual cortex.

Conclusion

The lower involvement of brain regions observed in Takotsubo patients suggests an impairment in emotion regulation, which might be of etiological importance in this brain-heart disease.

Brain functional connectivity is altered in patients with Takotsubo Syndrome

Takotsubo syndrome (TTS) is an acute, reversible cardiomyopathy. The central autonomic nervous system (ANS) is believed to play a role in this disease. The aim of the present study was to investigate the patterns of brain functional connectivity in a sample of patients who had experienced a previous episode of TTS. Brain functional connectivity, both at rest and in response to the stressful stimulus of topical cold stimulation, was explored using functional magnetic resonance imaging (fMRI), network-based statistics (NBS) and graph theory analysis (GTA) in a population consisting of eight patients with a previous episode of TTS and eight sex- and age-matched controls. At rest, a network characterized by increased connectivity in the TTS group compared to controls and comprising elements of the central ANS was identified. GTA revealed increased local efficiency, clustering and strength in regions of the bilateral hippocampus in subjects with a previous episode of TTS. When stressed by local exposure to cold, the TTS group differed significantly from both a pre-stress baseline interval and from the control group, showing increased connectivity in a network that included the left amygdala and the right insula. Based on the results, patients with TTS display a reorganization of cortical and subcortical networks, including areas associated with the emotional response and autonomic regulation. The findings tend to support the hypothesis that a deregulation of autonomic control at the central level plays a significant role in this syndrome.

Takotsubo Syndrome - Predictable from brain imaging data

Takotsubo syndrome (TTS) is characterized by acute left ventricular dysfunction, with a hospital-mortality rate similar to acute coronary syndrome (ACS). However, the aetiology of TTS is still unknown. In the present study, a multivariate pattern analysis using machine learning with multimodal magnetic resonance imaging (MRI) data of the human brain of TTS patients and age- and gender-matched healthy control subjects was performed. We found consistent structural and functional alterations in TTS patients compared to the control group. In particular, anatomical and neurophysiological measures from brain regions constituting the emotional-autonomic control system contributed to a prediction accuracy of more than 82%. Thus, our findings demonstrate homogeneous neuronal alterations in TTS patients and substantiate the importance of the concept of a brain-heart interaction in TTS.

The Sympathetic Nervous System in the Pathogenesis of Takotsubo Syndrome

Takotsubo syndrome is a unique clinical condition of acute heart failure and reversible left ventricular dysfunction frequently precipitated by sudden emotional or physical stress. There is growing evidence that exaggerated sympathetic stimulation is central to the pathogenesis of this syndrome. Precisely how catecholamines mediate myocardial stunning in takotsubo syndrome remains incompletely understood; but possible mechanisms include epicardial spasm, microvascular dysfunction, direct adrenergic-receptor-mediated myocyte injury, and systemic vascular effects that alter ventricular-arterial coupling. Risk factors that increase sympathetic tone and/or catecholamine sensitivity may render individuals particularly susceptible to takotsubo syndrome during episodes of acute stress.

Challenges of Chronic Cardiac Problems in Survivors of Takotsubo Syndrome

A hallmark feature of the Takotsubo syndrome (TTS) is the reversible nature of the observed cardiac dysfunction. This is underlined in diagnostic criteria. However, it would appear this reversibility is a subtle process, and that myocardial catecholamine toxicity can cause lasting permanent abnormalities of myocardial physiology. A growing body of evidence suggests persisting abnormalities may predispose post-TTS patients to cardiac and noncardiac morbidity and mortality. The cardiology community needs to understand more clearly how TTS evolves, how to identify high-risk patients with incomplete resolution, and perform studies to assess which treatment(s) are effective to improve cardiac recovery and clinical outcomes.

Psychosocial and psychoneuroendocrinal aspects of Takotsubo syndrome

Great advances have been made in our understanding of Takotsubo syndrome in the past decade, but the aetiology of the condition remains incompletely understood. The most established theory, that catecholamine-mediated myocardial stunning is provoked by emotional or physiological stress, is supported by the presence of supraphysiological levels of plasma catecholamines in patients with Takotsubo syndrome. For this reason, the hyperexcitability of the autonomic nervous system under conditions of physical and emotional stress is often assessed in these patients. Observational studies have indicated that a predisposing influence of chronic or traumatic stress, anxiodepressive disorders, and maladaptive personality traits are linked to the pathogenesis of Takotsubo syndrome. Chronic stress can influence autonomic function through dysregulation of the hypothalamic-pituitary-adrenal axis and contribute to the development of cardiovascular disorders. In this Perspectives article, we discuss the current knowledge of the psychoneuroendocrinological and psychosocial mechanisms underlying the pathophysiology of Takotsubo syndrome.