Peri-ictal atrioventricular conduction block in a patient with a lesion in the left insula: case report and review of the literature

Heart Rate Variability in Insulo-Opercular Epilepsy

Background: We aimed to evaluate heart rate variability (HRV) changes in insulo-opercular epilepsy (IOE) and after insulo-opercular surgery. Methods: We analyzed 5-min resting HRV of IOE patients before and after surgery. Patients’ SUDEP-7 risk inventory scores were also calculated. Results were compared with age- and sex-matched patients with temporal lobe epilepsy (TLE) and healthy individuals. Results: There were no differences in HRV measurements between IOE, TLE, and healthy control groups (and within each IOE group and TLE group) in preoperative and postoperative periods. In IOE patients, the SUDEP-7 score was positively correlated with pNN50 (percentage of successive RR intervals that differ by more than 50 ms) (p = 0.008) and RMSSD (root mean square of successive RR interval differences) (p = 0.019). We stratified IOE patients into those whose preoperative RMSSD values were below (Group 1a = 7) versus above (Group 1b = 9) a cut-off threshold of 31 ms (median value of a healthy population from a previous study). In group 1a, all HRV values significantly increased after surgery. In group 1b, time-domain parameters significantly decreased postoperatively. Conclusions: Our results suggest that in IOE, HRV may be either decreased in parasympathetic tone or increased globally in both sympathetic and parasympathetic tones. We found no evidence that insulo-opercular surgeries lead to major autonomic dysfunction when a good seizure outcome is reached. The increase in parasympathetic tone observed preoperatively may be of clinical concern, as it was positively correlated with the SUDEP-7 score.

Insular seizures and epilepsies: Ictal semiology and minimal invasive surgery

PURPOSE OF REVIEW

The increased identification of seizures with insular ictal onset, promoted by the international development of stereo-electroencephalography (SEEG), has led to the recent description of larger cohorts of patients with insular or insulo-opercular epilepsies than those previously available. These new series have consolidated and extended our knowledge of the rich ictal semiology and diverse anatomo-clinical correlations that characterized insular seizures. In parallel, some experiences have been gained in the surgical treatment of insular epilepsies using minimal invasive procedures.

RECENT FINDINGS

The large majority of patients present with auras (mostly somatosensory and laryngeal) and motor signs (predominantly elementary and orofacial), an underlying focal cortical dysplasia, and an excellent postoperative seizure outcome. Many other subjective and objective ictal signs, known to occur in other forms of epilepsies, are also observed and clustered in five patterns, reflecting the functional anatomy of the insula and its overlying opercula, as well as preferential propagation pathways to frontal or temporal brain regions. A nocturnal predominance of seizure is frequently reported, whereas secondary generalization is infrequent. Some rare ictal signs are highly suggestive of an insular origin, including somatic pain, reflex seizures, choking spells, and vomiting. Minimal invasive surgical techniques have been applied to the treatment of insular epilepsies, including Magnetic Resonance Imaging-guided laser ablation (laser interstitial thermal therapy (LITT)), radiofrequency thermocoagulation (RFTC), gamma knife radiosurgery, and responsive neurostimulation. Rates of seizure freedom (about 50%) appear lower than that reported with open-surgery (about 80%) with yet a significant proportion of transient neurological deficit for LITT and RFTC.

SUMMARY

Significant progress has been made in the identification and surgical treatment of insular and insulo-opercular epilepsies, including more precise anatomo-clinical correlations to optimally plan SEEG investigations, and experience in using minimal invasive surgery to reduce peri-operative morbidity.

COMPLETE ATRIOVENTRICULAR BLOCK AND ASYSTOLE DURING EPILEPTIC SEIZURE: A CASE REPORT

Cardiac arrhythmias during or after epileptic seizures are one of the possible pathomechanisms of sudden unexpected death in epilepsy. These arrhythmogenic epilepsies are most commonly associated with sinus tachycardia, but atrioventricular block and asystole can also be seen. Although a rare occurrence, these arrhythmias can lead to significant morbidity and mortality, but also can be potentially preventable with pacemaker implantation. Here we describe a patient with recurrent epileptic seizures, diagnosed with ictal third-degree atrioventricular block and asystole during seizure, which required a permanent cardiac pacemaker.

Resolution of ictal bradycardia and asystole following temporal lobectomy: A case report, and review of available cases using pacemakers

Ictal bradycardia (IB) and ictal asystole (IA) are uncommonly recognized phenomena that increase morbidity in patients with epilepsy by causing syncope and seizure-related falls. These arrhythmias are also suspected to be involved in the pathophysiology of sudden unexpected death in epilepsy (SUDEP). We report a case of a 57-year-old male with left temporal lobe epilepsy who experienced both IB and IA. This patient was initially managed with pacemaker implantation, prior to undergoing left temporal lobectomy. Following surgery, the patient had no ongoing IB or IA on his pacemaker recordings, and his seizure control was greatly improved. His pacemaker was removed approximately one year post-operatively and he continued treatment with anti-seizure drugs (ASDs). A literature review of cases of IB and IA that were managed with pacemakers was performed. Pacemaker implantation appears to be quite effective for reducing seizure-related syncope and falls in the setting of IB/IA. Epilepsy surgery also seems to be an effective treatment option for IB/IA, as many patients are able to have their pacemakers removed post-operatively. Further investigations into the pathophysiology of IB and IA and long-term outcomes using different treatment modalities are clearly needed to help formulate treatment guidelines and, potentially, to reduce the occurrence of SUDEP in these patients.

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Pacemaker implantation reduce seizure related syncope and falls in the setting of ictal bradycardia and ictal asystole.

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Ictal bradycardia and ictal asystole may contribute to the pathophysiology of sudden unexpected death in epilepsy.

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Epilepsy surgery seems to be an effective treatment option for ictal bradycardia and ictal asystole related with seizures.

How the insula speaks to the heart: Cardiac responses to insular stimulation in humans

Despite numerous studies suggesting the role of insular cortex in the control of autonomic activity, the exact location of cardiac motor regions remains controversial. We provide here a functional mapping of autonomic cardiac responses to intracortical stimulations of the human insula. The cardiac effects of 100 insular electrical stimulations into 47 epileptic patients were divided into tachycardia, bradycardia, and no cardiac response according to the magnitude of RR interval (RRI) reactivity. Sympathetic (low frequency, LF, and low to high frequency powers ratio, LF/HF ratio) and parasympathetic (high frequency power, HF) reactivity were studied using RRI analysis. Bradycardia was induced by 26 stimulations (26%) and tachycardia by 21 stimulations (21%). Right and left insular stimulations induced as often a bradycardia as a tachycardia. Tachycardia was accompanied by an increase in LF/HF ratio, suggesting an increase in sympathetic tone; while bradycardia seemed accompanied by an increase of parasympathetic tone reflected by an increase in HF. There was some left/right asymmetry in insular subregions where increased or decreased heart rates were produced after stimulation. However, spatial distribution of tachycardia responses predominated in the posterior insula, whereas bradycardia sites were more anterior in the median part of the insula. These findings seemed to indicate a posterior predominance of sympathetic control in the insula, whichever the side; whereas the parasympathetic control seemed more anterior. Dysfunction of these regions should be considered when modifications of cardiac activity occur during epileptic seizures and in cardiovascular diseases.

The Insula and Its Epilepsies

Insular seizures are great mimickers of seizures originating elsewhere in the brain. The insula is a highly connected brain structure. Seizures may only become clinically evident after ictal activity propagates out of the insula with semiology that reflects the propagation pattern. Insular seizures with perisylvian spread, for example, manifest first as throat constriction, followed next by perioral and hemisensory symptoms, and then by unilateral motor symptoms. On the other hand, insular seizures may spread instead to the temporal and frontal lobes and present like seizures originating from these regions. Due to the location of the insula deep in the brain, interictal and ictal scalp electroencephalogram (EEG) changes can be variable and misleading. Magnetic resonance imaging, magnetic resonance spectroscopy, magnetoencephalography, positron emission tomography, and single-photon computed tomography imaging may assist in establishing a diagnosis of insular epilepsy. Intracranial EEG recordings from within the insula, using stereo-EEG or depth electrode techniques, can prove insular seizure origin. Seizure onset, most commonly seen as low-voltage, fast gamma activity, however, can be highly localized and easily missed if the insula is only sparsely sampled. Moreover, seizure spread to the contralateral insula and other brain regions may occur rapidly. Extensive sampling of the insula with multiple electrode trajectories is necessary to avoid these pitfalls. Understanding the functional organization of the insula is helpful when interpreting the semiology produced by insular seizures. Electrical stimulation mapping around the central sulcus of the insula results in paresthesias, while stimulation of the posterior insula typically produces painful sensations. Visceral sensations are the next most common result of insular stimulation. Treatment of insular epilepsy is evolving, but poses challenges. Surgical resections of the insula are effective but risk significant morbidity if not carefully planned. Neurostimulation is an emerging option for treatment, especially for seizures with onset in the posterior insula. The close association of the insula with marked autonomic changes has led to interest in the role of the insula in sudden unexpected death in epilepsy and warrants additional study with larger patient cohorts.

Who to target in sudden unexpected death in epilepsy prevention and how? Risk factors, biomarkers, and intervention study designs

The risk of dying suddenly and unexpectedly is increased 24- to 28-fold among young people with epilepsy compared to the general population, but the incidence of sudden unexpected death in epilepsy (SUDEP) varies markedly depending on the epilepsy population. This article first reviews risk factors and biomarkers for SUDEP with the overall aim of enabling identification of epilepsy populations with different risk levels as a background for a discussion of possible intervention strategies. The by far most important clinical risk factor is frequency of generalized tonic-clonic seizures (GTCS), but nocturnal seizures, early age at onset, and long duration of epilepsy have been identified as additional risk factors. Lack of antiepileptic drug (AED) treatment or, in the context of clinical trials, adjunctive placebo versus active treatment is associated with increased risks. Despite considerable research, reliable electrophysiologic (electrocardiography [ECG] or electroencephalography [EEG]) biomarkers of SUDEP risk remain to be established. This is an important limitation for prevention strategies and intervention studies. There is a lack of biomarkers for SUDEP, and until validated biomarkers are found, the endpoint of interventions to prevent SUDEP must be SUDEP itself. These interventions, be they pharmacologic, seizure-detection devices, or nocturnal supervision, require large numbers. Possible methods for assessing prevention measures include public health community interventions, self-management, and more traditional (and much more expensive) randomized clinical trials.

Cardiac and autonomic mechanisms contributing to SUDEP

Sudden unexpected death in epilepsy is likely caused by a cascade of events affecting the vegetative nervous system leading to cardiorespiratory failure and death. Multiple genetic, electrophysiological, neurochemical, and pharmacological cardiac alterations have been associated with epilepsy, which can affect autonomic regulation of the heart and predispose patients to sudden unexpected death in epilepsy. These cardiac and autonomic changes are more frequently seen in patients with longstanding and medication refractory epilepsy and may be a prerequisite for sudden unexpected death in epilepsy. Cardiac changes are also observed within the immediate periictal period in patients with and without preexisting cardiac pathology and could be the tipping point in the cascade of events compromising autonomic, respiratory, and cardiac function during an epileptic convulsion. Better understanding if and how these cardiac alterations can make a particular individual with epilepsy more susceptible to sudden unexpected death in epilepsy will hopefully lead us to more effective preventative strategies.

Ictal bradycardia and atrioventricular block: a cardiac manifestation of epilepsy

We describe a case of a patient with recurrent syncopal episodes that ultimately was discovered to be due to ictal bradycardia caused by temporal lobe epilepsy. A diagnostic dilemma was presented by a 55-year-old male who had recurrent syncopal events despite having an atrial pacemaker. The patient was noted to have automatisms and was diagnosed via electrocardiogram/electroencephalogram (EEG/ECG) co-registration to have ictal bradycardia and atrioventricular (AV) block leading to syncope. He was successfully managed with seizure control with the use of levetiracetam. Ictal bradycardia and AV block are uncommon manifestations of epilepsy and can progress to complete heart block and asystole. Diagnosis is best performed with simultaneous ECG and EEG recordings. Definitive management is seizure control with the use of antiepileptic drugs, with the question of pacemaker placement still up for debate.

Cardiac manifestations of neurologic disorders

The cardiac complications of certain neurologic diseases have been well recognized for over 50 years and are mostly evident for cerebrovascular accidents. Although these complications are frequent and in most circumstances benign, detrimental cardiac side effects, such as serious arrhythmias and myocardial infarctions, may occur. The link to most of these cardiac derangements is a transient or chronic autonomic dysfunction, depending on the specific neurologic disease. Myocardial infarcts, left ventricular dysfunction, and arrhythmias are well-recognized complications of subarachnoid hemorrhage, intracranial bleed, and ischemic strokes. Seizures may present with atonia or sudden death from asystole. Degenerative brain disorders, namely the synucleinopathies, may affect the central control areas or peripheral ganglia of the autonomic nervous system, causing autonomic dysfunction. In addition, cardiac conduction defects and cardiomyopathy are common in certain neuromuscular disorders, namely the dystrophies and mitochondrial myopathies.

Prolonged atrial fibrillation following generalized tonic-clonic seizures

We describe two male patients with focal epilepsy in whom transitory episodes of atrial fibrillation (AF) lasting for up to 25h were detected in the context of generalized tonic-clonic seizures (GTCSs). In five of seven previously published cases of transitory AF associated with epileptic seizures, AF was also associated with GTCS, suggesting a pathophysiological link via GTCS-related increase in sympathetic tone and release of catecholamines. Importantly, AF increases the risk of thromboembolic cerebral ischemia, prompting the question of whether antithrombotic preventive treatment should be initiated in people with pharmacoresistant epilepsy and prolonged peri-ictal AF. Furthermore, AF can considerably impair cardiac output and may, via this mechanism, contribute to the risk of sudden unexpected death in epilepsy following GTCS.

Increased prevalence of temporary cardiac pacing in people with epilepsy

INTRODUCTION

Even though ictal tachyarrhythmias are more common, ictal brady-asystole is more likely to be fatal, and yet is potentially preventable with pacemaker (PM) implantation. We sought to quantify the degree of association of PM placement in people with and without epilepsy, including neurological and cardiovascular cohorts.

METHODS

Retrospective cross-sectional analysis of the National Hospital Discharge database using International Classification of Diseases Clinical Modification (ICD-9-CM) codes. We identified people with and without epilepsy between 1990 and 2006. The epilepsy cohort was compared to patients without epilepsy and other cardiovascular and central nervous system (CNS) disease cohorts.

RESULTS

People with epilepsy had higher odds of temporary PM (TPM; OR 1.6) than patients without epilepsy, especially amongst males (OR 2.0), young- (OR 4.6) and middle-aged (OR 4.3) patients. The epilepsy cohort had significantly higher odds of TPM than demyelinating disease (OR 7.9) and migraine (OR 9.1) cohorts. Compared to stroke, people with epilepsy had higher odds of TPM in the male (OR 1.6) and middle-age (OR 2.4) subgroups. No significant association was seen with permanent PM (PPM).

CONCLUSIONS

Our study demonstrates the high likelihood of TPM placement in epilepsy patients as compared to cohorts without epilepsy. Significant associations were seen especially in males and young- and middle-aged patients. Since demyelinating and migraine cohorts are somewhat similar to epilepsy patients in age and sex characteristics, the higher odds of TPM in epilepsy patients may be related to the disease mechanism causing brady-asystole; however this requires further study.

Peri-ictal prolonged atrial fibrillation after generalized seizures: description of a case and etiopathological considerations

Cardiac rhythm changes are not uncommon in connection with seizures and should be considered and recognized given their potentially harmful consequences including Sudden Unexpected Death in Epilepsy (SUDEP). The most well known are ictal tachycardia and bradycardia. However, other potentially dangerous peri-ictal arrhythmias have been reported. Brief atrial fibrillation episodes, never longer than 2 min, have rarely been described in connection with seizures. We report the case of a patient who presented with two generalized tonic-clonic seizures associated with prolonged atrial fibrillation. Extensive non-invasive cardiac investigations failed to disclose cardiac abnormalities, and after proper antiepileptic drug treatment the patient had neither further seizures nor cardiac events in an 18-month follow-up. Our case, to our knowledge, is the first report of prolonged (more than 1 h) peri-ictal atrial fibrillation.

Lacosamide-induced second-degree atrioventricular block in a patient with partial epilepsy

Dose-dependent PR interval prolongation has been reported in preclinical studies of lacosamide (LCM), a recently U.S. Food and Drug Administration (FDA)-approved antiepileptic drug (AED). Here we report a case of second-degree atrioventricular block (AV) block caused by the addition of LCM to other AEDs known to prolong the PR interval, resulting in hypotension and bradycardia, with consequent seizure exacerbation. The patient recovered completely after withdrawal of LCM. This case demonstrates the need for caution and interval cardiac testing when adding LCM to other AEDs known to prolong the PR interval.

Evaluation of Heart Rate Variation Analysis during Rest and Tilting in Patients with Temporal Lobe Epilepsy

Objective. To evaluate spectral heart rate (HR) variation using short-term ECG recordings at rest and during the tilt table test. Methods. The values of spectral components of total power (TP), high-frequency power (HF), low-frequency power (LF) and LF: HF ratio were measured at rest and during the head-up tilt in patients with temporal lobe epilepsy (TLE) and their control subjects. Results. Compared to the control subjects, patients with TLE had lower HF (P < 0.05) and LF : HF ratio (P < 0.05) at rest and lower TP (P < 0.001), HF (P < 0.05), and LF (P < 0.05) during the head-up tilt. Upon changing from supine to standing position TP (P < 0.05) and LF (P < 0.05) were attenuated in patients with TLE compared to the control subjects. Conclusion. These results suggest that spectral analysis of HR variation from ECG recordings of short duration may add value to assessment of autonomic nervous system function using autonomic cardiac tests in patients with TLE.

Management and long-term outcome in patients presenting with ictal asystole or bradycardia

PURPOSE

Ictal asystole (IA) and ictal bradycardia (IB) are rare autonomic symptoms during epileptic seizures and may be potentially life-threatening. Guidelines for the care of these patients are missing. The aim of this multicenter study was to evaluate the management and long-term outcome in patients with IA and IB.

PATIENTS AND METHODS

All patients with IA and IB were included from four epilepsy centers (Bielefeld, Kork, Marburg, and Zürich) from 2002 until 2009. Using a standardized assessment form, clinical data, treatment decisions, and outcomes were extracted from patient charts and simultaneous electroencephalography/electrocardiography (EEG/ECG) recordings.

KEY FINDINGS

Seizures with IA or IB were identified in 16 patients. In all patients an associated temporal seizure pattern was recorded and in 15 patients, sudden falls, fainting, or trauma was previously reported or recorded during the monitoring. In three patients (18.8%) diagnosis of focal epilepsy was newly established and anticonvulsive treatment was initiated. Two patients with refractory epilepsy underwent epilepsy surgery. In seven patients (43.8%) a cardiac pacemaker was implanted. In 14 of 16 treated patients, seizure freedom (n = 5) or absence of sudden falls, fainting, or trauma (n = 9) could be achieved. Two patients denied epilepsy surgery as well as a pacemaker and continue to have frequent falls and trauma.

SIGNIFICANCE

Our study demonstrates that epilepsy surgery and antiepileptic drugs may lead to sustained freedom of seizures as well as ictal syncope. In drug-resistant patients not suitable for epilepsy surgery, implantation of a cardiac pacemaker may prevent sudden falls as well as trauma. Based on our results and previously reported cases we propose a treatment algorithm.

Too long or too short? New insights into abnormal cardiac repolarization in people with chronic epilepsy and its potential role in sudden unexpected death

SUMMARY

Sudden unexpected death in epilepsy (SUDEP) is probably caused by periictal cardiorespiratory alterations such as central apnea, bradyarrhythmia, and neurogenic pulmonary edema. These alterations may occur in people with epilepsy and vary in duration and severity. Seizure-related ventricular tachyarrhythmias have also been hypothesized to be involved in SUDEP, but compelling evidence of these, or of predisposition to these, is lacking. Ventricular tachyarrhythmias are facilitated by pathologic cardiac repolarization. Electrocardiography (ECG) indicators of pathologic cardiac repolarization, such as prolongation or shortening of QT intervals as well as increased QT dispersion, are established risk factors for life-threatening tachyarrhythmia and sudden cardiac death (SDC). Abnormalities in cardiac repolarization have recently been described in people with epilepsy. Importantly, periictal ventricular tachycardia and fibrillation have also been reported in the absence of any underlying cardiac disease. Therefore, pathologic cardiac repolarization could promote SCD in people with epilepsy and could be one plausible cause for SUDEP. Herein, we review abnormal cardiac repolarization in people with epilepsy, describe the putative contribution of antiepileptic drugs, and discuss the potential role of pathologic cardiac repolarization in SUDEP. Based on these, measures to reduce the risk of or prevent SUDEP may include antiarrhythmic medication and implantation of cardiac combined pacemaker-defibrillator devices.