Brain seizes, heart ceases: a case of ictal asystole

Syncope vs. Seizure: Ictal Bradycardia and Ictal Asystole

Background

Ictal arrhythmia is a rare condition that causes arrhythmic manifestations induced by epileptic seizures, including asystole or bradycardia. Ictal asystole (IA) is a very rare condition found in patients undergoing video-encephalography (EEG) monitoring. It is often related to temporal lobe epilepsy and can cause syncope, which can lead to injury or even death. Case Presentation. Two patients with epilepsy showed symptoms of syncope. Both patients underwent 4-day ambulatory EEG tests and were diagnosed with IA. Following the tests, the patients were implanted with a permanent pacemaker, and one of them underwent a temporal lobectomy. As a result of these procedures, the patients experienced a reduction in episodes of symptomatic syncope.

Conclusion

Patients with ictal asystole and symptomatic ictal bradycardia are at increased risk of falls due to seizures. Although there are no specific guidelines for managing this condition, antiseizure medications, epilepsy surgery, and cardiac pacemaker implantation have been effective treatments.

Generalized tonic-clonic seizures with post-ictal atrial fibrillation

Convulsive seizures are known to cause severe cardiopulmonary changes and increased autonomic activity. Limited reports describe peri-ictal cardiac arrhythmias such as atrial fibrillation (AF) with generalized tonic–clonic seizures (GTCS). We present a unique case of a healthy 23-year-old male patient with new onset prolonged AF in the setting of new onset seizures, occurring on three independent occasions. Over two years, our patient had multiple hospitalizations for seizures with an electrocardiogram (ECG) diagnosis of AF made on three different occasions, occurring during his post-ictal state (all within 30 min of seizure onset). These seizures were never captured by electroencephalography (EEG) or witnessed by the medical staff, but were reported by family and/or reviewed on video provided by them. After his first GTCS, his AF persisted and was medically cardioverted. Two additional instances of AF after witnessed GTCS have been captured. After his second unprovoked seizure, an anti-seizure drug (ASD) was prescribed. A multi-disciplinary approach may be adopted to address comorbidities associated with seizures. Aggressive evaluation and treatment should be employed for newly diagnosed and refractory seizure patients associated with arrhythmias, in our case AF. Peri-ictal arrhythmias may be considered a potential marker for increased sudden unexpected death in epilepsy (SUDEP) risk.

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Association of new onset post-ictal atrial fibrillation (AF) with new onset generalized tonic-clonic seizure (GTCS) is rare

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Over a two year period, an overall healthy 23-year-old male was found to have three independent AF occurrences after GTCS

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A multi-disciplinary approach and aggressive treatment with anti-seizure drugs may be adopted to address such events

Ictal asystole: a case presentation

BACKGROUND

Epileptic seizures can lead to cardiac arrhythmias. The arrhythmias may be in the form of tachycardia, bradycardia or asystole. Ictal bradycardia and asystole can lead to sudden unexpected death.

CASE PRESENTATION

A case report of a 40-year-old male with complex partial temporal lobe epilepsy. He has coincident attacks of fall and pallor. The patient underwent simultaneous electrocardiogram (ECG) and video electroencephalogram (EEG) monitoring. The slow activity in EEG coincide with the appearance of bradycardia in ECG then cardiac asystole which clinically correspond to the patient syncope. After insertion of a cardiac pacemaker, only complex partial attacks develop with a marked reduction in frequency and no more fall attacks.

CONCLUSION

Epileptic seizures can present with cardiac arrhythmias, with ictal asystole leading to sudden unexpected death. Simultaneous EEG and ECG are essential for the diagnosis. A cardiac pacemaker can be lifesaving for patients with ictal arrhythmias.

Ictal asystole as the first presentation of epilepsy: A case report and systematic literature review

We report the case of a 69-year-old woman who presented with recurring episodes of mental confusion/dizziness followed by loss of consciousness, intense pallor, and sweating. Cardiologic investigations were unremarkable. The electroencephalogram recorded during one typical episode allowed the demonstration of a right frontotemporal seizure with progressive bradycardia leading to a 9-second asystole. Following levetiracetam treatment up to 2500 mg/day, seizures with ictal asystole (IA) recurred. An MRI compatible pacemaker was then implanted. At 26-month follow-up, the patient has not had further episodes of loss of consciousness. A systematic review (1950–Apr 2014) searching for cases in which IA was an early manifestation of epilepsy led to the observation of 31 cases. The time lag between the first seizures and the correct diagnosis of IA was long (average: 27 months; median: 12 months). Clinical history alone was not sufficient to prompt a correct diagnosis of IA, and only 11 out of 31 cases presented with symptoms suggestive of a seizure disorder. The majority of patients had a frontotemporal epilepsy with a slight prevalence of left-side involvement (19 out of 31).

Ictal bradycardia–asystole is an important condition that should be recognized by epileptologists, neurologists, as well as emergency department physicians. It is important to underscore that IA not only can occur in patients with drug-resistant epilepsy but also may be the first manifestation of the patient's epilepsy.

Sudden unexpected death in epilepsy

Sudden unexpected death in epilepsy (SUDEP) refers to the sudden death of a seemingly healthy individual with epilepsy, usually occurring during, or immediately after, a tonic-clonic seizure. The frequency of SUDEP varies depending on the severity of the epilepsy, but overall the risk of sudden death is more than 20 times higher than that in the general population. Several different mechanisms probably exist, and most research has focused on seizure-related respiratory depression, cardiac arrhythmia, cerebral depression, and autonomic dysfunction. Data from a pooled analysis of risk factors indicate that the higher the frequency of tonic-clonic seizures, the higher the risk of SUDEP; furthermore, risk of SUDEP is also elevated in male patients, patients with long-duration epilepsy, and those on antiepileptic polytherapy. SUDEP usually occurs when the seizures are not witnessed and often at night. In this Seminar, we provide advice to clinicians on ways to minimise the risk of SUDEP, information to pass on to patients, and medicolegal aspects of these deaths.

Kv1.1 potassium channel deficiency reveals brain-driven cardiac dysfunction as a candidate mechanism for sudden unexplained death in epilepsy

Mice lacking Kv1.1 Shaker-like potassium channels encoded by the Kcna1 gene exhibit severe seizures and die prematurely. The channel is widely expressed in brain but only minimally, if at all, in mouse myocardium. To test whether Kv1.1-potassium deficiency could underlie primary neurogenic cardiac dysfunction, we performed simultaneous video EEG-ECG recordings and found that Kcna1-null mice display potentially malignant interictal cardiac abnormalities, including a fivefold increase in atrioventricular (AV) conduction blocks, as well as bradycardia and premature ventricular contractions. During seizures the occurrence of AV conduction blocks increased, predisposing Kv1.1-deficient mice to sudden unexplained death in epilepsy (SUDEP), which we recorded fortuitously in one animal. To determine whether the interictal AV conduction blocks were of cardiac or neural origin, we examined their response to selective pharmacological blockade of the autonomic nervous system. Simultaneous administration of atropine and propranolol to block parasympathetic and sympathetic branches, respectively, eliminated conduction blocks. When administered separately, only atropine ameliorated AV conduction blocks, indicating that excessive parasympathetic tone contributes to the neurocardiac defect. We found no changes in Kv1.1-deficient cardiac structure, but extensive Kv1.1 expression in juxtaparanodes of the wild-type vagus nerve, the primary source of parasympathetic input to the heart, suggesting a novel site of action leading to Kv1.1-associated cardiac bradyarrhythmias. Together, our data suggest that Kv1.1 deficiency leads to impaired neural control of cardiac rhythmicity due in part to aberrant parasympathetic neurotransmission, making Kcna1 a strong candidate gene for human SUDEP.

Sinus node arrest secondary to HSV encephalitis

We report a patient with herpes simplex virus (HSV) encephalitis presenting as recurrent syncope due to sinus node arrest. Although the patient's initial presentation suggested a primary cardiac cause, an eventual diagnosis of HSV encephalitis was supported by computed tomography scan and magnetic resonance imaging, and confirmed by HSV polymerase chain reaction. The mechanism of cardiac arrhythmias in HSV encephalitis remains unclear; however, cardiac monitoring should be considered in all patients in whom the diagnosis is suspected. With diagnosis and appropriate management, a permanent pacemaker is generally not indicated. This case report highlights the importance of considering potentially reversible causes of collapse secondary to sinus node dysfunction beyond primary cardiac causes.

The ictal bradycardia syndrome: localization and lateralization

PURPOSE

Previous studies have established the importance of the insular cortex and temporal lobe in cardiovascular autonomic modulation. Some investigators, based on the results of cortical stimulation response, functional imaging, EEG recordings of seizures, and lesional studies, have suggested that cardiac sympathetic and parasympathetic function may be lateralized, with sympathetic representation lateralized to the right insula, and parasympathetic, to the left. These studies have suggested that ictal bradycardia is most commonly a manifestation of activation of the left temporal and insular cortex. However, the evidence for this is inconsistent. We sought to assess critically the predictable value of ictal bradycardia for seizure localization and lateralization.

METHODS

In this study, we reviewed the localization of seizure activity in 13 consecutive patients with ictal bradycardia diagnosed during prolonged video-EEG monitoring at Mayo Clinic Rochester. The localization of electrographic seizure activity at seizure onset and bradycardia onset was identified in all patients. In addition, we performed a comprehensive review of the ictal bradycardia literature focusing on localization of seizure activity in ictal bradycardia cases.

RESULTS

All occurrences of ictal bradycardia in the 13 identified patients were associated with temporal lobe-onset seizures. However, no consistent lateralization of seizure activity was found at onset of seizure activity or at onset of bradycardia in this population. Seizure activity was bilateral at bradycardia onset in nine of 13 patients. The results from the literature review also showed that a predominance of patients had bilateral activity at bradycardia onset; however, more of the ictal bradycardia cases from the literature had left hemispheric localization of seizure onset.

CONCLUSIONS

Ictal bradycardia most often occurs in association with bilateral hemispheric seizure activity and is not a consistent lateralizing sign in localizing seizure onset. Our data do not support the existence of a strictly unilateral parasympathetic cardiomotor representation in the left hemisphere, as has been suggested.

Does epilepsy surgery lower the mortality of drug-resistant epilepsy?

Drug-resistant epilepsy has proved to be associated with an increased standardized mortality ratio (SMR), primarily due to seizure-related fatalities including sudden unexpected death (SUDEP). Recent studies have suggested that the surgical cure of temporal lobe epilepsy (TLE) was likely to normalize the SMR of patients suffering from refractory TLE. However, these studies raise a number of methodological issues, which have not always been fully addressed. Some conclusions have relied on previously reported data, indicating a SMR of approximately 5, and a SUDEP incidence of 9/1000 patient-years in drug-resistant epilepsy. In fact, as shown in this review, SMR varied considerably, from 2 to 16, in the various series of patients with refractory epilepsy, whereas the average SUDEP incidence in the same populations was calculated at 3.7/1000 patient-years. Other conclusions were based on the comparison of either surgically and medically treated patients, or cured and non-cured operated patients. In both situations, the two groups included a different proportion of excellent and poor surgical candidates. The biological differences that distinguish these two populations might explain part of the differences observed in their mortality rate, regardless of the effect of surgery. In particular, temporal-plus epilepsies involving the insula, the frontal orbital, or the frontal operculum region, might favour ictal arrhythmias, central apnoea and secondary generalization, which in turn would increase the risk of SUDEP. Future studies are thus warranted to specifically address these issues.

Cardiac asystole in epilepsy: clinical and neurophysiologic features

PURPOSE

Cardiac asystole provoked by epileptic seizures is a rare but important complication in epilepsy and is supposed to be relevant to the pathogenesis of sudden unexplained death in epilepsy (SUDEP). We sought to determine the frequency of this complication in a population of patients with medically intractable epilepsy and to analyze the correlation between EEG, electrocardiogram (ECG), and clinical features obtained from long-term video-EEG monitoring.

METHODS

Retrospective analysis of the clinical records of hospitalized patients from May 1992 to June 2001 who underwent long-term video-/EEG monitoring.

RESULTS

Of a total of 1,244 patients, five patients had cardiac asystole in the course of ictal events. In these patients, 11 asystolic events, between 4 and 60 s long in a total of 19 seizures, were registered. All seizures had a focal origin with simple partial seizures (n = 13), complex partial seizures (n = 4), and secondarily generalized seizures (n = 2). One patient showed the longest asystole ever reported (60 s) because of a seizure. Cardiac asystole occurred in two patients with left-sided temporal lobe epilepsy (TLE) and in three patients with frontal lobe epilepsy (FLE; two left-sided, one bifrontal). Two patients reported previous cardiac disease, but only one had a pathologic ECG by the time of admission. Two patients had a simultaneous central ictal apnea during the asystole. None of the patients had ongoing deficits due to the asystole.

CONCLUSIONS

These findings confirm that seizure-induced asystole is a rare complication. The event appeared only in focal epilepsies (frontal and temporal) with a lateralization to the left side. A newly diagnosed or known cardiac disorder could be a risk factor for ictal asystole. Abnormally long postictal periods with altered consciousness might point to reduced cerebral perfusion during the event because of ictal asystole. Central ictal apnea could be a frequent associated phenomenon.

Heart rate changes and ECG abnormalities during epileptic seizures: prevalence and definition of an objective clinical sign

PURPOSE

To determine the prevalence of heart rate changes and ECG abnormalities during epileptic seizures and to determine the timing of heart rate changes compared to the first electrographic and clinical signs. To assess the risk factors for the occurrence of ECG abnormalities.

METHODS

We analyzed retrospectively 281 seizures in 81 patients with intractable epilepsy who had prolonged video-EEG and two-channel ECG. The nature and timing of heart rate changes compared to the electrographic and clinical seizure onset was determined. The ictal period (including one minute preictally and three minutes postictally) was analyzed for cardiac arrhythmias, conduction and repolarization abnormalities. Risk factors for cardiac abnormalities were investigated using parametric and non-parametric statistics.

RESULTS

There was an increase in heart rate of at least 10 beats/minute in 73% of seizures (93% of patients) and this occurred most often around seizure onset. In 23% of seizures (49% of patients) the rate increase preceded both the electrographic and the clinical onset. ECG abnormalities were found in 26% of seizures (44% of patients). One patient had an asystole for 30 seconds. Long seizure duration increased the occurrence of ECG abnormalities. No other risk factor was found.

CONCLUSIONS

Heart rate changes occur frequently and occur around the time or even before the earliest electrographic or clinical change. The change can clarify the timing of seizure onset and the specific rate pattern may be useful for seizure diagnosis and for automatic seizure detection. ECG abnormalities occur often and repeatedly in several seizures of the same patient.

Heart rate changes during partial seizures: a study amongst Singaporean patients

INTRODUCTION

Studies in Europe and America showed that tachycardia, less often bradycardia, frequently accompanied partial seizures in Caucasian patients. We determine frequency, magnitude and type of ictal heart rate changes during partial seizures in non-Caucasian patients in Singapore.

METHODS

Partial seizures recorded during routine EEGs performed in a tertiary hospital between 1995 and 1999 were retrospectively reviewed. All routine EEGs had simultaneous ECG recording. Heart rate before and during seizures was determined and correlated with epileptogenic focus. Differences in heart rate before and during seizures were grouped into 4 types: (1) >10% decrease; (2) -10 to +20% change; (3) 20-50% increase; (3) >50% increase.

RESULTS

Of the total of 37 partial seizures, 18 were left hemisphere (LH), 13 were right hemisphere (RH) and 6 were bilateral (BL) in onset. 51% of all seizures showed no significant change in heart rate (type 2), 22% had moderate sinus tachycardia (type 3), 11% showed severe sinus tachycardia (type 4), while 16% had sinus bradycardia (type 1). Asystole was recorded in one seizure. Apart from having more tachycardia in bilateral onset seizures, there was no correlation between side of ictal discharge and heart rate response. Compared to Caucasian patients, sinus tachycardia was considerably less frequent. Frequency of bradycardia was similar to those recorded in the literature.

CONCLUSIONS

Significant heart rate changes during partial seizures were seen in half of Singaporean patients. Although sinus tachycardia was the most common heart rate change, the frequency was considerably lower compared to Caucasian patients. This might be due to methodological and ethnic differences. Rates of bradycardia are similar to those recorded in the literature.