Cardiac asystole during right frontal lobe seizures: a case report

Abstract The association between partial seizures and cardiac asystole has rarely been reported in the literature. This potentially life-threatening symptom has been observed principally in left-sided epilepsies, in particular during seizures originating in temporal lobe. We describe a case with ictal bradycardia followed by cardiac asystole during right frontal lobe seizures. Video-EEG monitoring recorded two partial seizures with electro-clinical findings suggestive of a right frontal lobe origin, associated with ictal bradycardia followed by prolonged asystole. The brain MRI showed a lesion located in the cingulate gyrus of the right frontal lobe. The patient required a subsequent placement of a pacemaker. In conclusion, cardiac asystole may be a potentially life-threatening symptom during seizures of frontal lobe origin. The right fronto-mesial structures may play a role in autonomic regulation of cardiovascular responses.     

The association of cardiac asystole with partial seizures: does it result from ictal or interictal activity?

Bradycardia or asystole that occur during some seizures may be life threatening as a leading cause of SUDEP. A patient with right and left temporal lobe onset seizures and preceding bardycardia or asystole is presented. He had bilateral hippocampal atrophy on MRI. The unreliability of ictal bradycardia or asystole as a lateralizing sign in patients with partial epilepsy and the role of interictal autonomic activity in heart rate changes during seizures are discussed.     

Ictal asystole with convulsive syncope mimicking secondary generalisation: a depth electrode study

Ictal bradycardia is rare and its localising value is debated. Bradyarrhythmias are, however, important because of their potential connection to sudden death and ability to affect clinical seizure manifestations. Cerebral hypoperfusion induces loss of consciousness, at times with myoclonic jerks, whose clinical differentiation from a generalised convulsive seizure may prove difficult.Two invasive and five surface monitored seizures recorded over two years in a 51 year old woman with post-traumatic epilepsy characterised by seizure-triggered asystole were analysed. All seven seizures showed left temporal onset. Both intracranially recorded events started in the left anterior hippocampus/amygdala, spreading to the contralateral hippocampus in 35 and 25 seconds. Within 10 seconds an electrocardiogram showed asystole lasting 21 and 28 seconds, associated with suppression of recorded cerebral electrical activity, except a polyspike suppression pattern remaining in the hippocampi. Clinically, the patient, concomitantly with the cerebral suppression, developed myoclonic twitches of the limbs. A dual chamber cardiac pacemaker was implanted; at 11 months follow up, the patient has experienced only infrequent partial seizures, with none involving falls or shaking.Left temporal lobe seizures produced convulsive syncope initiated by ictal asystole. These observations suggest that intertemporal spread is necessary, though not sufficient, to produce bradycardia and asystole. Furthermore, pacemakers may decrease seizure severity, as well as potentially protect against malignant bradyarrhythmias.     

Ictal asystole mimicking seizure deterioration in temporal lobe epilepsy

We report on a patient with temporal lobe epilepsy, secondary to a left lateral temporal cavernoma, in whom the change in seizure semiology suggested recurrence of secondary generalized seizures. Anticonvulsive medication previously controlled secondary generalized seizures over a period of years but focal seizures continued at a lower rate. Continuous video‐EEG monitoring revealed ictal asystole associated with myoclonic syncope and falls during focal seizures arising from the left temporal lobe. After implantation of a cardiac pacemaker, no more falls occurred during the focal seizures. In conclusion, recurrence of seizure‐associated falls is typically attributed to recurrence of secondary generalized seizures, however, ictal asystole should be considered in selected epilepsy patients as a differential diagnosis of falls. [Published with video sequence]     

Cerebral arrhythmia influencing cardiac rhythm: a case of ictal bradycardia.

Partial seizures of temporal origin can be associated with clinically significant tachycardia or bradycardia. Ictal bradycardia and asystole has been implicated in the etiology of sudden unexpected death in epileptic patients (SUDEP). Although symptomatic ictal bradycardia has been relatively well described in the literature; information on asymptomatic ictal bradycardia is scarce. We report a case of asymptomatic ictal bradycardia diagnosed during video EEG telemetry that was subsequently implanted with a cardiac pacemaker.     

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.     

Comparison of clinical and electrophysiological characteristics between ictal and cardiac asystole encountered during video-EEG monitoring

Aims. Differentiation between syncope secondary to epileptic seizures and cardiac disease in patients displaying transient loss of consciousness associated with convulsive movements is a diagnostic challenge both for neurologists and cardiologists. In such patients, prolonged video-EEG monitoring not only helps in identifying asystole as the cause of syncope, but also in categorizing asystole as primarily cardiac in origin (cardiac asystole) and secondary to epileptic seizures (ictal asystole). We carried out this study to ascertain the prevalence of asystole in an epilepsy monitoring unit, and to contrast the clinical and electrophysiological characteristics between ictal asystole and cardiac asystole. Methods. Through a retrospective search, we identified patients who were shown to have had asystole using a database of patients who underwent prolonged video-EEG monitoring during a 68-month period. We compared the data of 18 consecutive patients; five with ictal asystole and 13 with cardiac asystole, with 121 and 64 events recorded from them, respectively. Results. Of the 10,096 patients who underwent prolonged video-EEG monitoring during the study period, we identified 18 (0.17%) patients with asystole. Cardiac asystole was 2.6 times more frequent than ictal asystole. Older age at onset, heralding symptoms of presyncope, occurrence during wakefulness, and brief duration of the events supported the diagnosis of cardiac asystole. Ictal asystole events were more protracted, and prolonged asystole more frequently occurred in patients with extratemporal seizures compared to temporal lobe seizures. Asystole occurred in only half of the recorded seizures. Conclusions. The accurate categorization of asystole as seizure-related or heart disease-related has huge implications for management strategy and outcome. The necessity of permanent pacemaker implantation is more frequent and urgent in patients with cardiac asystole because of the greater risk of sudden death. Hence, in patients with an ominous diagnosis of cardiac asystole, a thorough cardiac evaluation should surpass neurological evaluation.     

Clinical cues for detecting ictal asystole

Objective The occurrence of asystole during an epileptic seizure is the most dramatic manifestation of ictal bradycardia. Recognition of ictal asystole is important as treatment with both antiepileptic drugs and cardiac pacing may be necessary. The purpose of this study was to identify clinical cues to aid in the detection of ictal asystole. Methods We analyzed the clinical and electrophysiologic features of all recorded seizures in consecutive patients diagnosed with ictal bradycardia and asystole on prolonged video-EEG/ECG monitoring over a 14 year period. Results Twenty-nine seizures with ictal bradycardia were identified in 13 patients. Of these, 11 seizures in seven patients were associated with asystole. Bilateral transient limb movements consisting of asymmetric posturing or jerking occurred during eight episodes of ictal asystole, and loss of muscle tone occurred during four. In contrast, neither bilateral limb movement nor loss of muscle tone was observed in any of the non-asystolic seizures, whether ictal bradycardia was present or not. All patients with ictal asystole reported a history of seizure-related falls and brief body and limb jerking. Conclusions The presence of loss of muscle tone or bilateral asymmetric jerky limb movements during a seizure suggests the possibility of ictal asystole. Video-EEG/ECG monitoring should be considered in patients with epilepsy demonstrating these clinical features to determine if ictal asystole is present.     

Ictal asystole in temporal lobe epilepsy before and after pacemaker implantation.

Events of ictal bradycardia or asystole may be of relevance in epilepsy patients presenting with ictal falls, and are a potential contributor to SUDEP. The literature on ictal bradycardia or asystole is anecdotal and consists of case reports and small case series. There are no guidelines for the care of patients with ictal arrhythmias. Insertion of cardiac pacemakers may prevent life-threatening cardiac arrest, syncope and trauma.We report the case of a 41-year-old man who presented with refractory partial seizures resulting in syncope leading to severe head trauma, as the only ictal semiology. During presurgical video-EEG monitoring, two episodes of ictal bradycardia followed by asystole and syncope were recorded. A cardiac pacemaker was implanted. At the nine-month follow-up, the patient reported no overt seizures, syncopes or traumatic falls. Our case demonstrates that implantation of a cardiac pacemaker while continuing AEDs may render a patient free from ictal symptoms and prevent ictal syncope and subsequent trauma. [Published with video sequences].     

Syncope,seizure-induced bradycardia and asystole: Two cases and review of clinical and pathophysiological features

Episodes of transient loss of consciousness (TLOC) are commonly due to syncope or epileptic seizures. The distinction between both entities on clinical grounds and eyewitness accounts can be challenging and is often hampered by similar clinical features. We briefly summarize syncope-related symptoms and present the case of a female patient who suffered from TLOC episodes due to both reflex syncope and epileptic seizures. Seizure-induced syncope is a rare complication particularly of non-generalized temporal lobe seizures and may be suspected in people with epilepsy who report new semiological features with sudden onset of atonia, TLOC and seizure-related falls. We review epidemiological, clinical and electroencephalographic aspects of seizure-related asystole and syncope and discuss their clinical relevance. The implantation of a cardiac pacemaker appears to efficiently prevent seizure-related falls and consecutive injuries and is an important treatment option if full seizure-control cannot be achieved in these patients. We describe a second case of a patient with refractory temporal lobe epilepsy and seizure-related syncope which ceased after the implantation of a cardiac pacemaker.     

Clustering syncope in a young male with temporal lobe seizures

We report the case of a male aged 2 years 6 months with left temporal lobe epilepsy who presented with ictal bradycardia syndrome leading to asystole. The clinical presentation was remarkable for the occurrence of clustering syncope. A seizure was recorded on a video electroencephalogram- electrocardiogram and analyzed. A cardiac pacemaker was implanted and antiepileptic drug treatment was initiated. We suggest that clustering of syncope is an important feature in the presentation of epilepsy in a young child.     

Bradycardia and asystole during generalised interictal EEG discharges

Few studies have investigated the effects of interictal epileptic discharges on the cardiac autonomic system. This study reports the case of a 37‐year‐old man with refractory generalised epilepsy, who recently reported an increase in frequency of nocturnal tonic‐clonic seizures, not responding to treatment. During the nocturnal video study, in non‐rapid eye movements sleep, we recorded 106 generalised sharp‐ and polyspike‐waves lasting for 3 to 7 seconds, associated with bradycardia and asystole, without behavioural changes and without increase in deltoid muscle activity. The asystole had a duration of between 3 and 8 seconds. In one case, a 7 second asystole was associated with a tonic‐clonic generalised seizure. A 24‐hour electrocardiographic study revealed a bradycardia and a Wenckebach atrioventricular block. Heart rate analysis at the time of the interictal epileptic discharges revealed an abrupt increase in the RR interval, occurring simultaneously with the onset of interictal epileptic discharges and followed by a return to values below baseline value. A cardiac pacemaker was installed with a reduction of asystole length during the interictal epileptic discharges. Our findings indicate, for the first time, the role of interictal generalised discharges in EEG‐related asystole and bradycardia. These data support the hypothesis that some patients with epilepsy may be predisposed to disturbances of the autonomic cardiac system.     

Ictal bradycardia in a patient with a hypothalamic hamartoma: a stereo-EEG study

Little is known about bradycardia and cardiac asystole which occur during partial epileptic seizures, especially whether they relate to ictal involvement of well-defined cortical areas. Several reports based on simultaneous electrocardiographic and intracranial depth electroencephalographic monitoring have shown that either the fronto-orbital cortex or the amygdalohippocampal complex could be responsible for such cardiac variations. We performed stereo-EEG recordings in a patient with refractory localization-related epilepsy associated with a hypothalamic hamartoma. We found that other cortical areas, such as the frontocentral region and the temporal neocortex, can contribute to the genesis of ictal bradyarrhythmia. Second, the lesion per se, although located within the hypothalamus, is not involved with this phenomenon.     

Temporal lobe seizures triggering recurrent syncope by ictal asystole

Described here is a case of a patient with left temporal lobe epilepsy and recurrent complex partial seizures associated with asystole. The posturing and myoclonus caused by the nonepileptogenic syncope during the asystole gave the appearance of secondary generalization prompting a surgical evaluation. A distinct atonic phase that interrupts the transition from a complex partial semiology to generalization is a critical clue to the presence of ictal asystole and is easily detected by video/EEG monitoring.     

SCN8A-related developmental and epileptic encephalopathy with ictal asystole requiring cardiac pacemaker implantation

IntroductionSCN8A-related epilepsy has various phenotypes. In particular, patients with developmental and epileptic encephalopathy (DEE) are resistant to antiepileptic drugs and may present with autonomic symptoms, such as marked bradycardia and apnea during seizures, and thus have an increased risk of sudden death. Herein, we report a case of very severe SCN8A-related epilepsy necessitating cardiac pacemaker implantation because of repetitive ictal asystole.Case reportThe patient was a 14-month-old girl. Tremor and generalized tonic seizure occurred after birth. During seizures, bradycardia and perioral cyanosis occurred, and then, after developing tachycardia and apnea, marked bradycardia and generalized cyanosis occurred, which sometimes resulted in ictal asystole requiring cardiopulmonary resuscitation. Her seizures were refractory to antiepileptic drugs. As the seizures requiring resuscitation did not decrease, cardiac pacemaker implantation was performed four months after birth. Exome sequencing revealed a heterozygous de novo variant in SCN8A (NM_014191.3:c.4934T>C,p.(Met1645Thr)). Even though phenytoin was effective, seizures with bradycardia remained approximately once a month, and pacemaker activity was observed.ConclusionsThis is, to our knowledge, the first reported case of SCN8A-related DEE in whom pacemaker implantation was performed. Pacemaker implantation should be considered as a treatment option for critical patients with SCN8A-related DEE as in the present case, because the incidence of sudden unexpected death in epilepsy is reported to be approximately 10% in patients with SCN8A-related DEE.     

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.     

Accurate diagnosis of convulsive syncope: role of an implantable subcutaneous ECG monitor.

Convulsive syncope due to transient bradycardia is recognized as a cause of treatment-resistant seizures. However, the diagnosis may be difficult to make with conventional electrocardiographic devices if attacks are infrequent. We present a case of apparent epilepsy in which a new implantable electrocardiographic event recorder (the 'Reveal' insertable loop recorder) was used to show that attacks were caused by prolonged asystole of up to 36 s in duration. The insertable loop recorder may have an important role in the investigation of patients with treatment-resistant seizures, particularly where there is a strong suspicion of an underlying cardiac arrhythmia.     

Autonomic alterations and cardiac changes in epilepsy

Studies with heart rate variability have revealed interictal autonomic alterations in patients with epilepsy. In addition, epilepsy is frequently associated with ictal tachycardia or bradycardia, which sometimes precedes the onset of seizures. Ictal tachycardia is sometimes associated with electrocardiography (ECG) morphologic changes and ictal bradycardia often progresses to asystole. Such cardiac manifestations of seizures have been hypothesized as possible causes for sudden unexplained death in epilepsy (SUPEP). The present review relates to interictal and ictal cardiac manifestations of epilepsy with focus on heart rate, heart rate variability, and ECG changes. Aspects of the supporting mechanisms are discussed and attention is drawn to the interaction between central and peripheral effects, interictal autonomic conditions, ictal autonomic discharges, and administration of antiepileptic drugs in shaping the ictal cardiac changes. Because these interactions are complex and not totally understood, closer surveillance of patients and more experimental work is necessary to elucidate the mechanistic support of autonomic and cardiac changes in epilepsy, and to design better strategies to avoid their undesirable effects. It is also suggested that some of these changes could be used as predictors or markers for the onset of seizures.     

Relation between ictal asystole and cardiac sympathetic dysfunction shown by MIBG‐SPECT

Objective – Tachyarrhythmias are common during epileptic seizures while bradyarrhythmias or asystoles are less frequent. Ictal asystole might be related to epilepsy‐induced cardiac sympathetic denervation. Methods – To evaluate cardiac post‐ganglionic denervation in epilepsy patients with ictal asystoles we assessed I¹²³‐meta‐iodobenzylguanidine (MIBG) as a marker of post‐ganglionic cardiac norepinephrine‐uptake, using single photon emission computed tomography (MIBG‐SPECT). Results – In five of 844 patients with presurgical video‐electroencephalography‐monitoring, we recorded ictal asystoles during nine of 37 seizures. Asystole patients underwent cardiologic examination (Holter‐electrocardiogram, echocardiogram) and cardiac MIBG‐SPECT. We compared cardiac MIBG uptake in the asystole patients to the uptake in 18 temporal lobe epilepsy (TLE) patients without bradyarrhythmias and in 14 controls without cardiac or neurological disease. As the cardiological examinations were unremarkable in all subjects, the heart/mediastinum‐MIBG‐uptake ratios (H/M‐ratios) differed significantly between the three groups (P = 0.004). H/M‐ratios were lower in asystole TLE patients (mean ± SD: 1.58 ± 0.3) than in patients without asystole (1.81 ± 0.18; P = 0.037) or controls (1.96 ± 0.16). Conclusions – Pronounced reduction in cardiac MIBG uptake of asystole patients indicates post‐ganglionic cardiac catecholamine disturbance. Impaired sympathetic cardiac innervation limits adjustment and heart rate modulation, and may increase the risk of asystole and ultimately sudden unexpected death in epilepsy (SUDEP).     

Ictal asystole: A benign condition?

Ictal asystole (IA) has been implicated as a preventable cause of sudden unexplained death in epilepsy presumably provoked by a direct autonomic effect of the electrical stimulus on the heart. An electronic database search of patients with IA was performed comparing heart rate (HR) characteristics to a group of patients with vasovagal asystole. IA was seen in eight patients, all with temporal lobe epilepsy. No statistical difference was found in duration of asystole, bradycardia, and baseline HR characteristics except of a higher HR acceleration postasystole in the controls. None of the six patients with IA who underwent pacemaker implantation had recurrence of asystolic events during mean follow-up of 5 years. This study in a small group of patients suggests that the epileptic activation leading to IA is possibly mediated through a transient increase in vagal tone and not by a direct autonomic effect on the heart.