Epileptic heart: A clinical syndromic approach

Intracellular calcium dysregulation in heart and brain diseases: Insights from induced pluripotent stem cell studies

The central nervous system (CNS) plays a role in regulating heart rate and myocardial contractility through sympathetic and parasympathetic nerves, and the heart can impact the functional equilibrium of the CNS through feedback signals. Although heart and brain diseases often coexist and mutually influence each other, the potential links between heart and brain diseases remain unclear due to a lack of reliable models of these relationships. Induced pluripotent stem cells (iPSCs), which can differentiate into multiple functional cell types, stem cell biology and regenerative medicine may offer tools to clarify the mechanisms of these relationships and facilitate screening of effective therapeutic agents. Because calcium ions play essential roles in regulating both the cardiovascular and nervous systems, this review addresses how recent iPSC disease models reveal how dysregulation of intracellular calcium might be a common pathological factor underlying the relationships between heart and brain diseases.

Cardiovascular risk factor assessment in late-onset seizures: A study protocol to assess the value of structured intervention

OBJECTIVE

A growing body of evidence suggests patients with late-onset seizures are at an increased risk of stroke, but the potential for reducing cardiovascular morbidity through risk factor screening and management is unknown. We aim to determine whether individuals with new-onset unprovoked seizures after middle age should undergo vascular risk assessment. The long follow-up needed to assess stroke risk and the known benefit of vascular risk factor modification make a standard RCT logistically and ethically challenging. Instead, we propose and have developed a protocol for a cluster project assessing the effect of vascular risk factor screening in an intervention trial as well as a cohort study.

METHODS

Participating neurology clinics will implement standard cardiovascular risk factor assessment into the routine evaluation for individuals aged ≥50 years attending their first specialized consultation after an unprovoked seizure, excluding those with progressive brain disease. The project has two interlinked components: a prospective single group trial, in which risk factor assessment is performed and subsequent management is followed for one year; and a register-based cohort study examining the long-term effects of the intervention on a system level by comparing patients attending initial consultations in the 2 years after start of the study, with patients seen in the four preceding years at the same clinics.

ANALYSIS

The primary outcome of the intervention trial is the proportion of patients receiving subsequent pharmacological treatment. The primary outcome of the cohort study is the incidence of acute stroke in the Swedish Stroke Register.

ETHICS AND DISSEMINATION

Swedish Ethical Review Authority approval (which is valid for 2 years only) will be sought when funding is obtained. The results will be disseminated through peer-reviewed scientific publications.

REGISTRATION DETAILS

The study will be registered at clinicaltrials.gov.

PLAIN LANGUAGE SUMMARY

A first seizure in a middle-aged or older person indicates a higher risk of stroke. It is not known whether investigating and treating blood pressure, blood cholesterol, or similar risk factors after a first seizure is an effective way to prevent stroke. A traditional clinical study would need too many patients and it would be unethical not to treat the control group. We have designed a study in which participating neurology departments change their practice to test and treat vascular risk factors. Patients are then compared to historic controls using registered data.

Improving epilepsy diagnosis across the lifespan: approaches and innovations

Epilepsy diagnosis is often delayed or inaccurate, exposing people to ongoing seizures and their substantial consequences until effective treatment is initiated. Important factors contributing to this problem include delayed recognition of seizure symptoms by patients and eyewitnesses; cultural, geographical, and financial barriers to seeking health care; and missed or delayed diagnosis by health-care providers. Epilepsy diagnosis involves several steps. The first step is recognition of epileptic seizures; next is classification of epilepsy type and whether an epilepsy syndrome is present; finally, the underlying epilepsy-associated comorbidities and potential causes must be identified, which differ across the lifespan. Clinical history, elicited from patients and eyewitnesses, is a fundamental component of the diagnostic pathway. Recent technological advances, including smartphone videography and genetic testing, are increasingly used in routine practice. Innovations in technology, such as artificial intelligence, could provide new possibilities for directly and indirectly detecting epilepsy and might make valuable contributions to diagnostic algorithms in the future.

Association of minor electrocardiographic (ECG) abnormalities with epilepsy duration in children: A manifestation of the epileptic heart?

PURPOSE

Cardiac abnormalities resulting from chronic epilepsy ("the epileptic heart") constitute a well-recognized comorbidity. However, the association of cardiac alterations with epilepsy duration remains understudied. We sought to evaluate this association using electrocardiogram (ECG).

METHODS

We prospectively enrolled children between 1 months and 18 years of age without known cardiac conditions or ion channelopathies during routine clinic visits. ECGs were categorized as abnormal if there were alterations in rhythm; PR, QRS, or corrected QT interval; QRS axis or morphology; ST segment or T wave. An independent association between ECG abnormalities and epilepsy duration was evaluated using multivariable logistic regression modeling.

RESULTS

213 children were enrolled. 100 ECGs (47%) exhibited at least one alteration; most commonly in the ST segment (37, 17%) and T wave (29, 11%). Children with normal ECGs had shorter epilepsy duration as compared to those with ECG abnormalities (46 [18-91] months vs. 73 [32-128 months], p = 0.004). A multivariable logistic regression model demonstrated that increasing epilepsy duration was independently associated with the presence of ECG abnormalities (OR=1.09, 95% CI=1.02-1.16, p = 0.008), adjusted for seizure frequency, generalized tonic-clonic/focal to bilateral tonic-clonic seizures as the predominant seizure type, and number of channel-modifying anti-seizure medications. Increasing epilepsy duration was also independently associated with the presence of ST/T wave abnormalities (OR=1.09, 95% CI=1.01-1.16, p = 0.017), adjusted for the same covariates.

SIGNIFICANCE

Increasing epilepsy duration is independently associated with the presence of minor ECG abnormalities. Additional studies are needed to evaluate whether this finding may represent a manifestation of the "epileptic heart".

The epileptic heart: Cardiac comorbidities and complications of epilepsy. Atrial and ventricular structure and function by echocardiography in individuals with epilepsy - From clinical implications to individualized assessment

Epilepsy is an increasing global neurological health issue. Recently, epidemiological and mechanistic studies have raised concern about cardiac involvement in individuals with epilepsy. This has resulted in the "epileptic heart" concept. Epidemiological data linking epilepsy to cardiovascular disease indicate an increased risk for ventricular and atrial arrhythmias, myocardial infarction, heart failure, and sudden death among individuals with epilepsy. Pathways of this interaction comprise increased prevalence of traditional cardiac risk factors, genetic abnormalities, altered brain circuitry with autonomic imbalance, and antiseizure medications with enzyme-inducing and ionic channel-blocking proprieties. Pathophysiological findings in the atria and ventricles of patients with epilepsy are discussed. Echocardiographic findings and future applications of this tool are reviewed. A risk stratification model and future studies on cardiac risk assessment in individuals with epilepsy are proposed.

Cardiac dysfunctions in children with drug-resistant epilepsy

Objective

There were reports of cardiac dysfunction that led to sudden unexpected death in epilepsy (SUDEP) in patients with epilepsy. Early detection of cardiac dysfunction can lead to early management to prevent sudden cardiac death in these patients. The objective of our study is to assess cardiac functions in children with drug-resistant epilepsy (DRE) compared with the normal population by using a standard echocardiogram (SE), tissue Doppler imaging (TDI) and myocardial strain evaluations (MSE).

Method

Twenty-seven children who have been diagnosed with DRE based on the International League against Epilepsy (ILAE) were included in the study, along with 27 children whose ages match those of the normal control group.

Results

Seventeen children, median age 12 years old, were using more than four anti-seizure medications. Structural brain lesions were the most common cause of epilepsy, 55.6% (15). Generalized tonic-clonic seizures were the most common seizure type, 55.6% (15). Children with DRE had a lower early mitral valve E wave inflow velocity compared with the control group (p < 0.05). They also had lowered early diastolic velocities (e') and myocardial performance index (MPI) when compared with the control group (p < 0.05). There was a statistically significant difference in left ventricular myocardial strain in children with DRE, with an average of -21.1 (IQR -23.5 and -19.4) and control, -25.5 (IQR -27.3 and -24.2).

Significance

Children with DRE have an impairment of left ventricular diastolic function and myocardial strain, which could indicate decreased myocardial deformation and contraction compared with controls. These cardiological assessments can be used to evaluate children with DRE for early diagnosis and management of their cardiac dysfunction.

Challenges and directions in epilepsy diagnostics and therapeutics: Proceedings of the 17th Epilepsy Therapies and Diagnostics Development conference

Substantial efforts are underway toward optimizing the diagnosis, monitoring, and treatment of seizures and epilepsy. We describe preclinical programs in place for screening investigational therapeutic candidates in animal models, with particular attention to identifying and eliminating drugs that might paradoxically aggravate seizure burden. After preclinical development, we discuss challenges and solutions in the design and regulatory logistics of clinical trial execution, and efforts to develop disease biomarkers and interventions that may be not only seizure-suppressing, but also disease-modifying. As disease-modifying treatments are designed, there is clear recognition that, although seizures represent one critical therapeutic target, targeting nonseizure outcomes like cognitive development or functional outcomes requires changes to traditional designs. This reflects our increasing understanding that epilepsy is a disease with profound impact on quality of life for the patient and caregivers due to both seizures themselves and other nonseizure factors. This review examines selected key challenges and future directions in epilepsy diagnostics and therapeutics, from drug discovery to translational application.

Characteristics of deceased subjects transported to a postmortem imaging center due to unusual death related to epilepsy

OBJECTIVE

Patients with epilepsy have high risk of experiencing uncommon causes of death. This study aimed to evaluate patients who underwent unusual deaths related to epilepsy and identify factors that may contribute to these deaths and may also include sudden unexpected death in epilepsy (SUDEP).

METHODS

We analyzed 5291 cases in which a postmortem imaging (PMI) study was performed using plane CT, because of an unexplained death. A rapid troponin T assay was performed using peripheral blood samples. Clinical information including the cause of death suspected by the attending physician, body position, place of death, medical history, and antiseizure medications was evaluated.

RESULTS

A total of 132 (2.6%) patients had an obvious history of epilepsy, while 5159 individuals had no history of epilepsy (97.4%). Cerebrovascular disease was the cause of death in 1.6% of patients in the group with epilepsy, and this was significantly lower than that in the non-epilepsy group. However, drowning was significantly higher (9.1% vs. 4.4%). Unspecified cause of death was significantly more frequent in the epilepsy group (78.0% vs. 57.8%). Furthermore, the proportion of patients who demonstrated elevation of troponin T levels without prior cardiac disease was significantly higher in the epilepsy group (37.9% vs. 31.1%). At discovery of death, prone position was dominant (30.3%), with deaths occurring most commonly in the bedroom (49.2%). No antiseizure medication had been prescribed in 12% of cases, while 29.5% of patients were taking multiple antiseizure medications.

SIGNIFICANCE

The prevalence of epilepsy in individuals experiencing unusual death was higher than in the general population. Despite PMI studies, no definitive cause of death was identified in a significant proportion of cases. The high troponin T levels may be explained by long intervals between death and examination or by higher incidence of myocardial damage at the time of death.

PLAIN LANGUAGE SUMMARY

This study investigated unusual deaths in epilepsy patients, analyzing 5291 postmortem imaging cases. The results showed that 132 cases (2.6%) had a clear history of epilepsy. In these cases, only 22% cases were explained after postmortem examination, which is less than in non-epilepsy group (42.2%). Cerebrovascular disease was less common in the epilepsy group, while drowning was more common. Elevated troponin T levels, which suggest possibility of myocardial damage or long intervals between death and examination, were also more frequent in the epilepsy group compared to non-epilepsy group.

Hypertension and other vascular risk factors in patients with functional seizures

OBJECTIVE

Recent literature has suggested that functional seizures are associated with an elevated risk for vascular disease and mortality. We investigated the prevalence of risk factors for vascular disease in patients who were admitted to the epilepsy monitoring unit.

METHODS

Patients who were admitted to the epilepsy monitoring unit and received a definitive diagnosis of either functional seizures or epilepsy were identified. Data collected included demographic, clinical characteristics, medication list, comorbidities, and scheduled blood pressure measurements that occurred every 12 h during the admission. The mean blood pressures were calculated and if they were above the American College of Cardiology and the American Heart Association guideline cutoff of 130/80 mm Hg or the patient had a documented history of hypertension the patient was counted as having the condition. A multiple logistic regression model was developed to evaluate the independent association of the patient's diagnosis (i.e., epilepsy or functional seizures) and vascular risk factors that controlled for the number of blood pressure measurements, age, sex, and if the patient was taking antihypertensive medications.

RESULTS

270 patients were included in this study of which 147 patients had epilepsy and 123 had functional seizures. Among those with functional seizures, 57.72 % had either a history of hypertension or a mean blood pressure above 130/80 compared to 38.78 % of those with epilepsy (p = 0.0022). In addition, 30.89 % of functional seizures patients had hyperlipidemia and 63.41 % were obese. The logistic regression model indicated that functional seizures were independently associated with high blood pressure (OR: 2.47, 95 % CI 1.10-5.69), hyperlipidemia (OR: 3.38, 95 % CI 1.35-8.86), and obesity (OR: 4.25, 95 % CI 2.22-8.36) compared to those with epilepsy. There was no significant difference in the prevalence of diabetes (OR: 0.81, 95 % CI 0.24-2.77) or current tobacco use (OR: 1.04, 95 % CI 0.48-2.25) between the groups.

SIGNIFICANCE

Patients with functional seizures had an elevated prevalence of several vascular risk factors. These findings may partially account for complications associated with functional seizures and have implications related to their pathophysiology.

Epilepsy and long-term risk of arrhythmias

BACKGROUND AND AIMS

Previous evidence has mainly supported transient changes in cardiac function during interictal or peri-ictal phases in people with epilepsy, but the long-term risk of cardiac arrhythmias is poorly described. This study aimed to assess the long-term association of epilepsy with cardiac arrhythmias, considering the potential role of genetic predisposition and antiseizure medications (ASMs) in any associations observed.

METHODS

This population-based study evaluated UK Biobank data for individuals recruited between 2006 and 2010. Cox proportional hazards models and competing risk models were used to examine the association of epilepsy history with the long-term incidence risk of cardiac arrhythmias and arrhythmias subtypes. Polygenic risk scores (PRS) were calculated to investigate the effect of genetic susceptibility. The role of ASMs was also evaluated by integrating observational and drug target Mendelian randomization (MR) evidence.

RESULTS

The study included 329 432 individuals, including 2699 people with epilepsy. Compared with those without epilepsy, people with epilepsy experienced an increased risk of all cardiac arrhythmias [hazard ratio (HR) 1.36, 95% confidence interval (CI) 1.21-1.53], atrial fibrillation (HR 1.26, 95% CI 1.08-1.46), and other cardiac arrhythmias (HR 1.56, 95% CI 1.34-1.81). The associations were not modified by genetic predisposition as indicated by PRS. Competing and sensitivity analyses corroborated these results. Individuals with epilepsy using ASMs, especially carbamazepine and valproic acid, were at a higher risk for cardiac arrhythmias. This observation was further supported by drug target MR results (PSMR < .05 and PHEIDI > .05).

CONCLUSION

This study revealed the higher risk of cardiac arrhythmias persists long term in people with epilepsy, especially among those using carbamazepine and valproic acid. These findings highlight the need for regular heart rhythm monitoring and management in people with epilepsy in order to reduce the risk of further cardiovascular complications.

Exploring Autonomic Alterations during Seizures in Temporal Lobe Epilepsy: Insights from a Heart-Rate Variability Analysis

Epilepsy's impact on cardiovascular function and autonomic regulation, including heart-rate variability, is complex and may contribute to sudden unexpected death in epilepsy (SUDEP). Lateralization of autonomic control in the brain remains the subject of debate; nevertheless, ultra-short-term heart-rate variability (HRV) analysis is a useful tool for understanding the pathophysiology of autonomic dysfunction in epilepsy patients. A retrospective study reviewed medical records of patients with temporal lobe epilepsy who underwent presurgical evaluations. Data from 75 patients were analyzed and HRV indices were extracted from electrocardiogram recordings of preictal, ictal, and postictal intervals. Various HRV indices were calculated, including time domain, frequency domain, and nonlinear indices, to assess autonomic function during different seizure intervals. The study found significant differences in HRV indices based on hemispheric laterality, language dominancy, hippocampal atrophy, amygdala enlargement, sustained theta activity, and seizure frequency. HRV indices such as the root mean square of successive differences between heartbeats, pNN50, normalized low-frequency, normalized high-frequency, and the low-frequency/high-frequency ratio exhibited significant differences during the ictal period. Language dominancy, hippocampal atrophy, amygdala enlargement, and sustained theta activity were also found to affect HRV. Seizure frequency was correlated with HRV indices, suggesting a potential relationship with the risk of SUDEP.

A unified hypothesis of SUDEP: Seizure-induced respiratory depression induced by adenosine may lead to SUDEP but can be prevented by autoresuscitation and other restorative respiratory response mechanisms mediated by the action of serotonin on the periaqueductal gray

Sudden unexpected death in epilepsy (SUDEP) is a major cause of death in people with epilepsy (PWE). Postictal apnea leading to cardiac arrest is the most common sequence of terminal events in witnessed cases of SUDEP, and postconvulsive central apnea has been proposed as a potential biomarker of SUDEP susceptibility. Research in SUDEP animal models has led to the serotonin and adenosine hypotheses of SUDEP. These neurotransmitters influence respiration, seizures, and lethality in animal models of SUDEP, and are implicated in human SUDEP cases. Adenosine released during seizures is proposed to be an important seizure termination mechanism. However, adenosine also depresses respiration, and this effect is mediated, in part, by inhibition of neuronal activity in subcortical structures that modulate respiration, including the periaqueductal gray (PAG). Drugs that enhance the action of adenosine increase postictal death in SUDEP models. Serotonin is also released during seizures, but enhances respiration in response to an elevated carbon dioxide level, which often occurs postictally. This effect of serotonin can potentially compensate, in part, for the adenosine-mediated respiratory depression, acting to facilitate autoresuscitation and other restorative respiratory response mechanisms. A number of drugs that enhance the action of serotonin prevent postictal death in several SUDEP models and reduce postictal respiratory depression in PWE. This effect of serotonergic drugs may be mediated, in part, by actions on brainstem sites that modulate respiration, including the PAG. Enhanced activity in the PAG increases respiration in response to hypoxia and other exigent conditions and can be activated by electrical stimulation. Thus, we propose the unifying hypothesis that seizure-induced adenosine release leads to respiratory depression. This can be reversed by serotonergic action on autoresuscitation and other restorative respiratory responses acting, in part, via the PAG. Therefore, we hypothesize that serotonergic or direct activation of this brainstem site may be a useful approach for SUDEP prevention.

Heart rate variability modifications in adult patients with early versus late-onset temporal lobe epilepsy: A comparative observational study

OBJECTIVES

Temporal lobe epilepsy (TLE) is the most frequent form of focal epilepsy. TLE is associated with cardio-autonomic dysfunction and increased cardiovascular (CV) risk in patients over the fifth decade of age. In these subjects, TLE can be classified as early-onset (EOTLE; i.e., patients who had developed epilepsy in their youth) and late-onset (LOTLE; i.e., patients who developed epilepsy in adulthood). Heart rate variability (HRV) analysis is useful for assessing cardio-autonomic function and identifying patients with increased CV risk. This study compared changes in HRV occurring in patients over the age of 50, with EOTLE or LOTLE.

METHODS

We enrolled twenty-seven adults with LOTLE and 23 with EOTLE. Each patient underwent a EEG and EKG recording during 20-minutes of resting state and a 5-minutes hyperventilation (HV). Short-term HRV analysis was performed both in time and frequency domains. Linear Mixed Models (LMM) were used to analyze HRV parameters according to the condition (baseline and HV) and group (LOTLE and EOTLE groups).

RESULTS

Compared to the LOTLE group, the EOTLE group showed significantly decreased LnRMSSD (natural logarithm of the root mean square of the difference between contiguous RR intervals) (p-value=0.05), LnHF ms² (natural logarithm of high frequency absolute power) (p-value=0.05), HF n.u. (high frequency power expressed in normalized units) (p-value=0.008) and HF% (high frequency power expressed in percentage) (p-value=0.01). In addition, EOTLE patients exhibited increased LF n.u. (low frequency power expressed in normalized units) (p-value=0.008) and LF/HF (low frequency/high frequency) ratio (p-value=0.007). During HV, the LOTLE group exhibited a multiplicative effect for the interaction between group and condition with increased LF n.u. (p = 0.003) and LF% (low frequency expressed in percentage) (p = 0.05) values.

CONCLUSIONS

EOTLE is associated with reduced vagal tone compared to LOTLE. Patients with EOTLE may have a higher risk of developing cardiac dysfunction or cardiac arrhythmia than LOTLE patients.

Cardiac structural and functional abnormalities in epilepsy: A systematic review and meta-analysis

OBJECTIVE

Epilepsy is associated with an increased risk of cardiovascular disease and mortality. Whether cardiac structure and function are altered in epilepsy remains unclear. To address this, we conducted a systematic review and meta-analysis of studies evaluating cardiac structure and function in patients with epilepsy.

METHODS

We searched the electronic databases MEDLINE, PubMed, COCHRANE, and Web of Science from inception to 31 December 2021. Primary outcomes of interest included left ventricular ejection fraction (LVEF) for studies reporting echocardiogram findings and cardiac weight and fibrosis for postmortem investigations. Study quality was assessed using the National Heart, Lung, and Blood Institute (NHLBI) assessment tools.

RESULTS

Among the 10 case-control studies with epilepsy patients (n = 515) and healthy controls (n = 445), LVEF was significantly decreased in epilepsy group compared with controls (MD: -1.80; 95% confidence interval [CI]: -3.56 to -0.04; P = 0.045), whereas A-wave velocity (MD: 4.73; 95% CI: 1.87-7.60; P = 0.001), E/e' ratio (MD: 0.39; 95% CI: 0.06-0.71; P = 0.019), and isovolumic relaxation time (MD: 10.18; 95% CI: 2.05-18.32; P = 0.014) were increased in epilepsy, compared with controls. A pooled analysis was performed in sudden unexpected death in epilepsy (SUDEP) cases with autopsy data (n = 714). Among SUDEP cases, the prevalence of cardiac hypertrophy was 16% (95% CI: 9%-23%); cardiac fibrosis was 20% (95% CI: 15%-26%). We found no marked differences in cardiac hypertrophy, heart weight, or cardiac fibrosis between SUDEP cases and epilepsy controls.

SIGNIFICANCE

Our findings suggest that epilepsy is associated with altered diastolic and systolic echocardiogram parameters compared with healthy controls. Notably, SUDEP does not appear to be associated with a higher incidence of structural cardiac abnormalities, compared with non-SUDEP epilepsy controls. Longitudinal studies are needed to understand the prognostic significance of such changes. Echocardiography may be a useful noninvasive diagnostic test in epilepsy population.

Gene mutations in comorbidity of epilepsy and arrhythmia

Epilepsy is one of the most common neurological disorders, and sudden unexpected death in epilepsy (SUDEP) is the most severe outcome of refractory epilepsy. Arrhythmia is one of the heterogeneous factors in the pathophysiological mechanism of SUDEP with a high incidence in patients with refractory epilepsy, increasing the risk of premature death. The gene co-expressed in the brain and heart is supposed to be the genetic basis between epilepsy and arrhythmia, among which the gene encoding ion channel contributes to the prevalence of "cardiocerebral channelopathy" theory. Nevertheless, this theory could only explain the molecular mechanism of comorbid arrhythmia in part of patients with epilepsy (PWE). Therefore, we summarized the mutant genes that can induce comorbidity of epilepsy and arrhythmia and the possible corresponding treatments. These variants involved the genes encoding sodium, potassium, calcium and HCN channels, as well as some non-ion channel coding genes such as CHD4, PKP2, FHF1, GNB5, and mitochondrial genes. The relationship between genotype and clinical phenotype was not simple linear. Indeed, genes co-expressed in the brain and heart could independently induce epilepsy and/or arrhythmia. Mutant genes in brain could affect cardiac rhythm through central or peripheral regulation, while in the heart it could also affect cerebral electrical activity by changing the hemodynamics or internal environment. Analysis of mutations in comorbidity of epilepsy and arrhythmia could refine and expand the theory of "cardiocerebral channelopathy" and provide new insights for risk stratification of premature death and corresponding precision therapy in PWE.

Dysautonomia in people with epilepsy: A scoping review

BACKGROUND

Epilepsy is one of the most common neurological diseases and has high morbidity and mortality. Multiple methods for assessing dysautonomia have been reported; however, the patient characteristics and epilepsy features that drive any method selection are unclear. People with epilepsy (PWE) can experience sudden unexpected death in epilepsy (SUDEP) and one reason can be dysautonomia. If dysautonomia can be detected in PWE before a severe event, then it could complement and redirect patient treatment and monitoring.

OBJECTIVE

To map the available literature on dysautonomia in PWE and describe patients' characteristics and methods used to evaluate dysautonomia.

METHODS

We performed a scoping literature review. We searched PubMed, Scopus, Embase, and hand searched starting from the first registry in the literature until August 2019. Studies were independently assessed by three authors and two epileptologists. We present data in tables and summarize information according to the following structure: population, concepts, and context.

RESULTS

Thirty-five studies were included in the analysis with epidemiological designs including case reports (23), cross-sectional studies (4), case‒controls (7), and cohort studies (1). A total of 618 patients were enrolled. Heart rate variability, arrhythmia, blood pressure, the tilt-table test, polysomnography, respiratory function, and magnetic resonance imaging were the methods most commonly used to assess dysautonomia in PWE. A detailed description of the heart rate variability assessment is presented.

CONCLUSIONS

This review provides a broad description of the available literature identifying clinical findings, the most frequently reported assessment measurements of dysautonomia, in temporal lobe epilepsy and extratemporal epilepsies.

Identification of factors associated with new-onset vascular disease in patients admitted for video-EEG monitoring: A longitudinal cohort study

OBJECTIVE

People with epilepsy are at a higher risk of developing vascular disease. Understanding the risk factors in observational studies is hampered by the challenge in separating epilepsy-related risk and treatment-related risk, and uncertainty in the epilepsy diagnosis. This study aimed to identify factors associated with risk of subsequent vascular disease in patients with video-EEG monitoring (VEM) confirmed epilepsy.

METHODS

We included patients with a diagnosis of epilepsy and nonepileptic disorders between January 1, 1995, and December 31, 2015. Incident cardiovascular, cerebrovascular, and peripheral vascular disease was determined by linkage to a state-wide hospital admissions database between 1st July 1994 and 28th February 2018. Incidence was compared with the general population.

RESULTS

1728 patients (59.7% female, median age 35 years) underwent VEM, and were followed up for a median of 9.2 years (range 2.2-22.9 years). Eight-hundred and thirty -two were diagnosed with epilepsy and 896 nonepileptic disorders. The incidence of cerebrovascular disease was higher in both patients with epilepsy (incidence rate ratio [IRR] 1.78, p = 0.001) and with nonepileptic disorders (IRR 1.61, p < 0.001) than in the general population. Patients who took valproic acid (VPA) were at a lower risk of vascular disease than those taking enzyme-inducing antiseizure medications (EIASM, subdistribution hazard ratio [SHR] 0.42, p = 0.013), and those taking neither VPA nor EIASM (SHR 0.47, p = 0.03). There was no difference in the incidence of vascular disease between patients with epilepsy and those without epilepsy (SHR 0.94, p = 0.766). Factors associated with increased risk included age (SHR 1.04, p < 0.001), male sex (SHR 1.50, p = 0.017), and smoking (SHR 1.68, p = 0.017).

SIGNIFICANCE

In this study, both patients with epilepsy and without epilepsy had increased vascular risk. This suggests that the increased risk may be in part due to factors not directly related to epilepsy, such as EIASM use and vascular risk factors.

Epileptic seizures and Epilepsy Monitoring Unit admission disclose latent cardiac electrical instability

BACKGROUND

Sudden cardiac arrest results from cardiac electrical instability and is 3-fold more frequent in patients with chronic epilepsy than in the general population. We hypothesized that focal to bilateral tonic-clonic seizures (FTBTCS) would acutely impact T-wave alternans (TWA), a marker of cardiac electrical instability linked to an elevated risk for sudden cardiac death, more than focal seizures (FS) [focal aware seizures (FAS) and focal with impaired awareness seizures (FIAS)], due to their greater sympathetic stimulation of the heart. Since stress has been shown to cause significant TWA elevations in patients with heart disease, we also hypothesized that the early days of an inpatient admission to an epilepsy monitoring unit (EMU) would be associated with higher TWA levels compared to later hospital days in patients with chronic epilepsy, presumably due to stress.

DESIGN/METHODS

We analyzed the acute effects of seizures [FAS, FIAS, FTBTCS, and nonepileptic seizures (NES)] and day of hospital stay on TWA in 18 patients admitted to the EMU using high-resolution wireless electrocardiographic (ECG) patch monitors.

RESULTS

A total of 5 patients had FTBTCS, 7 patients had FS (2 FAS, 5 FIAS), and 3 patients had NES only during the index hospital stay. Four patients did not have any electroclinical seizures or NES. FTBTCS resulted in marked acute increases in ictal TWA from baseline (2 ± 0.3 µV) to ictal maximum (70 ± 6.1 µV, p < 0.0001), the latter exceeding the 60 µV cut point defined as severely abnormal. By comparison, while FAS and FIAS also provoked significant increases in TWA (from 2 ± 0.5 µV to 30 ± 3.3 µV, p < 0.0001), maximum ictal TWA levels did not reach the 47 µV cut point defined as abnormal. Heart rate increases during FTBTCS from baseline (62 ± 5.8 beats/min) to ictal maximum (134 ± 8.6 beats/min, an increase of 72 ± 7.2 beats/min, p < 0.02) were also greater (p = 0.014) than heart rate increases during FS (from 70 ± 5.2 beats/min to 118 ± 6.2 beats/min, an increase of 48 ± 2.6 beats/min, p < 0.03). In 3 patients with NES, TWA rose mildly during the patients' typical episodes (from 2 ± 0.6 µV to 14 ± 2.6 µV, p < 0.0004), well below the cut point of abnormality, while heart rate increases were observed (from 75 ± 1.3 to 112 ± 8.7 beats/min, an increase of 37 ± 8.9 beats/min, p = 0.03). Patients with EEG-confirmed electroclinical seizures recorded while in the EMU exhibited significantly elevated interictal TWA maxima (61 ± 3.4 µV) on EMU admission day which were similar in magnitude to ictal maxima seen during FTBTCS (70 ± 6.1 µV, p = 0.21). During subsequent days of hospitalization, daily interictal TWA maxima showed gradual habituation in patients with both FS and FTBTCS but not in patients with NES only.

CONCLUSIONS

This is the first study to our knowledge demonstrating that FTBTCS acutely provoke highly significant increases in TWA to levels that have been associated with heightened risk for sudden cardiac death in other patient populations. We speculate that mortality temporally associated with FTBTCS may, in some cases, be due to sudden cardiac death rather than respiratory failure. In patients with EEG-confirmed epilepsy, hospital admission is associated with interictal TWA maxima that approach those seen during FTBTCS, presumably related to stress during the early phase of hospitalization compared to later in the hospitalization, indicating cardiac electrical instability and potential vulnerability to sudden cardiac death related to stress independent of temporal relationships to seizures. The elevated heart rates observed acutely with seizures and on hospital Day 1 are consistent with a hyperadrenergic state and the effect of elevated sympathetic output on a vulnerable cardiac substrate, a phenomenon termed "the Epileptic Heart."

Atrial fibrillation is associated with a subsequent epilepsy diagnosis independent of stroke: A retrospective matched administrative cohort study on 149,632 patients

Recently there has been a rising interest in the identification and possible prevention of risk factors for epilepsies. In the present study, we investigated the potential association between atrial fibrillation (AF) and epilepsy in a German cohort of ambulatory patients aged ≥18 with an initial diagnosis of atrial fibrillation documented in 1274 general practices in Germany between January 2005 and December 2018. Using the IQVIA Disease Analyzer database, we identified 74,681 ambulatory patients with AF. These were matched 1:1 to patients without AF based on sex, age, index year, yearly consultation frequency, and defined co-diagnoses like stroke. Cox regression models were used to evaluate the association between AF and epilepsy. Within 10 years of the index date, 1.9% of individuals with AF and 1.5% of individuals without AF were diagnosed with epilepsy (log-rank p < 0.001). Atrial fibrillation was significantly associated with an increase in the incidence of epilepsy (Hazard Ratio (HR): 1.51, p < 0.001). The association was significant in all age groups, except in patients >80 years of age (HR: 1.29, p = 0.031). Our study demonstrates that AF is associated with an increased incidence of epilepsy. This finding could help understand the mechanisms of epilepsy in heart disease and to better protect affected individuals in the future.

Serious Cardiac Arrhythmias Detected by Subcutaneous Long-term Cardiac Monitors in Patients With Drug-Resistant Epilepsy

BACKGROUND AND OBJECTIVES

Epilepsy is associated with an increased risk of cardiovascular disease and premature mortality, including sudden unexpected death in epilepsy (SUDEP). Serious cardiac arrythmias might go undetected in routine epilepsy and cardiac investigations.

METHODS

This prospective cohort study aimed to detect cardiac arrhythmias in patients with chronic drug-resistant epilepsy (≥5 years duration) using subcutaneous cardiac monitors for a minimum follow-up duration of 12 months. Participants with known cardiovascular disease or those with abnormal 12-lead ECGs were excluded. The device was programmed to automatically record episodes of tachycardia ≥140 beats per minute (bpm), bradycardia ≤40 bpm for ≥3 seconds, or asystole ≥3 seconds.

FINDINGS

Thirty-one patients underwent subcutaneous cardiac monitoring for a median recording duration of 2.2 years (range 0.5-4.2). During this time, 28 patients (90.3%) had episodes of sustained (≥30 seconds) sinus tachycardia, 8/31 (25.8%) had sinus bradycardia, and 3 (9.7%) had asystole. Three patients (9.7%) had serious cardiac arrhythmias requiring additional cardiac interventions. Among them, 2 patients had prolonged sinus arrest and ventricular asystole (>6 seconds), leading to pacemaker insertion in one, and another patient with epileptic encephalopathy had multiple episodes of recurrent nonsustained polymorphic ventricular tachycardia and bundle branch conduction abnormalities. The time to first detection of a clinically significant cardiac arrhythmia ranged between 1.2 and 26.9 months following cardiac monitor insertion.

DISCUSSION

Implantable cardiac monitors detected a high incidence of clinically significant cardiac arrhythmias in patients with chronic drug-resistant epilepsy, which may contribute to the incidence of premature mortality, including SUDEP.

T-wave heterogeneity crescendo in the surface EKG is superior to heart rate acceleration for seizure prediction

We examined whether T-wave heterogeneity (TWH) on the surface electrocardiographic (EKG) could predict epileptic seizure onset. Patients with electroencephalography-confirmed generalized tonic-clonic seizures (GTCS) (n = 6) exhibited abnormal elevations in TWH (>80 µV) at baseline (105 ± 20.4 µV), which increased from 30 min prior to seizure without heart rate increases > 2 beats/min until 10 min pre-seizure. Specifically, TWH on 3-lead surface EKG patch recordings increased from 1-hour baseline to 30 min (<0.05), 20 min (p < 0.002), 10 min (p = 0.01), and 1 min (p = 0.01) before seizure onset. At 10 min following GTCS, TWH returned to 110 ± 20.3 µV, similar to baseline (p = 0.54). This pre-ictal TWH warning pattern was not present in patients with psychogenic nonepileptic seizures (PNES) (n = 3), as TWH did not increase until PNES and returned to baseline within 10 min after PNES. Acute elevations in TWH may predict impending GTCS and may discriminate patients with GTCS from those with behaviorally similar PNES.

How predictable is heart rate variability in Brazilian patients with drug-resistant mesial temporal lobe epilepsy?

This study aimed to compare heart rate variability (HRV) in patients with drug-resistant mesial temporal lobe epilepsy (MTLE) with healthy controls and to analyze their clinical and sociodemographic variables predictive for HRV. Thirty-nine consecutive patients with drug-resistant MTLE were included in the study. The control group included twenty-seven healthy participants matched by age and gender. Seven HRV indices (HR, RR, rMSSD, SDNN, LF, HF, and LF/HF) were compared between patients and controls. The clinical and sociodemographic variables independently associated with the HRV indices were identified by multiple linear regression. In comparison with controls, the patients with MTLE showed a significant reduction in RR, rMSSD, SDNN, LF, HF, and LF/HF indices (t value 1.97-5.97, p < 0.05). Multiple regression models showed that disease duration predicted 11-22% of the analyzed HRV indices. Time domain indices showed higher association with disease duration than coefficients in frequency domain. Patients with drug-resistant MTLE present cardiac autonomic tone dysfunction, showing a significant reduction in their HRV indices (RR, SDNN, rMSSD, LF, HF, and LF/HF). Disease duration has a negative association with all HRV indices. This study contributes to understanding the relationship between MTLE and the cardiac autonomic tone, with possible implications for sudden unexpected death in epilepsy.

Late-Onset Ictal Asystole and Falls Related to Severe Coronary Artery Stenosis: A Case Report

Introduction: Ictal asystole (IA) is a rare, underestimated, and life-threatening cause of transient loss of consciousness and fall. Current treatment options for seizures associated with IA usually include cardiac pacemaker implantation. We report, for the first time, a case of IA that is related to coronary stenosis, which was resolved after coronary angioplasty.

Case Presentation: A 73-year-old man had a 2-year history of focal seizures with impaired awareness. Three months before our observation, he started to have sudden falls resulting in injury on several occasions. General and neurological examinations, as well as brain MRI, were unremarkable. Interictal electroencephalography (EEG) showed bitemporal spiking. Ictal video-polygraphy revealed a diffuse electrodecrement, followed by a buildup of rhythmic 4–6 Hz sharp activity, which was more evident in the left temporal region. After the seizure onset, the ECG showed sinus bradycardia, followed by sinus arrest that was associated with the patient's fall from the standing position. Afterwards, sinus rhythm returned spontaneously. A diagnosis of IA was made. A comprehensive cardiologic evaluation revealed a sub-occlusive stenosis of the left anterior descending artery. Successful coronary angioplasty resolved IA, levetiracetam was added, and no seizure or fall has occurred in the following 20 months. Moreover, he underwent a 7-day Holter ECG monitoring, and no asystole was depicted.

Conclusion: The present case was unique as it shows the potential association between IA and coronary stenosis, also suggesting a possible therapeutic role for coronary angioplasty. It also highlights the importance of carefully investigating epilepsy patients with falls, especially in the elderly, since IA-related falls can be easily misdiagnosed in older age. Thus, if IA is identified, a deeper cardiac evaluation should be considered. As seen in our patient, non-invasive diagnostic examination including routine, prolonged, and exercise ECG, as well as echocardiogram, were readily available and were informative in diagnosing cardiac abnormalities that are amenable to specific treatment.

Cardiac Investigations in Sudden Unexpected Death in DEPDC5-Related Epilepsy

OBJECTIVE

Germline loss-of-function mutations in DEPDC5, and in its binding partners (NPRL2/3) of the mammalian target of rapamycin (mTOR) repressor GATOR1 complex, cause focal epilepsies and increase the risk of sudden unexpected death in epilepsy (SUDEP). Here, we asked whether DEPDC5 haploinsufficiency predisposes to primary cardiac defects that could contribute to SUDEP and therefore impact the clinical management of patients at high risk of SUDEP.

METHODS

Clinical cardiac investigations were performed in 16 patients with pathogenic variants in DEPDC5, NPRL2, or NPRL3. Two novel Depdc5 mouse strains, a human HA-tagged Depdc5 strain and a Depdc5 heterozygous knockout with a neuron-specific deletion of the second allele (Depdc5c/- ), were generated to investigate the role of Depdc5 in SUDEP and cardiac activity during seizures.

RESULTS

Holter, echocardiographic, and electrocardiographic (ECG) examinations provided no evidence for altered clinical cardiac function in the patient cohort, of whom 3 DEPDC5 patients succumbed to SUDEP and 6 had a family history of SUDEP. There was no cardiac injury at autopsy in a postmortem DEPDC5 SUDEP case. The HA-tagged Depdc5 mouse revealed expression of Depdc5 in the brain, heart, and lungs. Simultaneous electroencephalographic-ECG records on Depdc5c/- mice showed that spontaneous epileptic seizures resulting in a SUDEP-like event are not preceded by cardiac arrhythmia.

INTERPRETATION

Mouse and human data show neither structural nor functional cardiac damage that might underlie a primary contribution to SUDEP in the spectrum of DEPDC5-related epilepsies. ANN NEUROL 2022;91:101-116.

Epilepsy is associated with an increased incidence of heart failure diagnoses

OBJECTIVE

Epilepsy is a complex disease with serious consequences for the quality of life and prognosis of those affected. The importance of comorbidities in disease progression and prognosis has gained increasing recognition in recent years. In the present study, we investigated the potential association between epilepsy and heart failure in an outpatient cohort in Germany.

METHODS

Using the IQVIA Disease Analyzer database, we identified a total of 9646 patients with late-onset epilepsy and a matched cohort of equal size without late-onset epilepsy who were followed up between 2005 and 2018. Cox regression models were used to evaluate the potential association between epilepsy and heart failure.

RESULTS

Within 10 years of the index date, 28.6% of patients with epilepsy and 20.4% of patients without epilepsy had been diagnosed with HF (log-rank p < 0.001). The incidences were 36.3 cases per 1,000 patient years in the epilepsy cohort versus 23.1 cases in the non-epilepsy cohort. In regression analyses, epilepsy was significantly associated with the incidence of HF (Hazard Ratio (HR): 1.56, p < 0.001). The association was somewhat stronger in men (HR: 1.63, p < 0.001) than in women (HR: 1.49, p < 0.001). The HR in the epilepsy group decreased with increasing age.

CONCLUSION

Our study provides strong evidence that epilepsy is associated with an increased incidence of heart failure. This finding should help raise awareness of this important comorbidity and could trigger specific cardiovascular screening programs in patients with epilepsy.

Corpus Callosotomy in 3 Cavalier King Charles Spaniel Dogs with Drug-Resistant Epilepsy

Corpus callosotomy (CC) is an established palliative surgery for human patients with drug-resistant epilepsy (DRE), especially those with generalized seizures and multiple or unknown epileptogenic focus. However, there are no reports to describe CC in canine patients with epilepsy. Three client-owned Cavalier King Charles Spaniels with DRE are included in this case series. In presurgical evaluations, an apparent epileptogenic zone was not detected in each dog and CC was conducted. Total CC was performed in one dog, whereas the other two received partial CC. One dog recovered from surgery without any complications, but died suddenly by an unknown cause at 10 h after surgery. For the other two dogs, postoperative evaluations including seizure outcomes, complications, and quality of life of the dogs and owners were assessed for at least 12 months. Both dogs showed a remarkable decrease in seizure frequency (averaged 80.3% reduction) and severity after surgery. The antiseizure medications were maintained, and not only the mentation and activity of the dogs, but also the quality of life of dogs and owners were improved postoperatively. Although technical improvement and more large-scale studies are needed, CC is a treatment option for dogs with DRE in veterinary medicine.