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.     

Synkopen

Syncope occurs in approximately 25% of the population at least once during their lifetime. It therefore represents the most frequent differential diagnosis of an epileptic seizure. Depending on the prognosis and therapy, syncopes can be divided in cardiac syncope, syncope due to orthostatic hypotension and reflex syncope, of which vasovagal (neurocardiogenic) syncope is the most frequent type. Vasovagal syncope typically occurs after prolonged standing, the sight of blood, pain and medical procedures. The pathophysiology is not well understood. Genetic factors play a role as well, mainly following a complex mode of inheritance. Syncope can usually be differentiated from an epileptic seizure based on the medical history. Typical vasovagal triggers, a typical prodrome and pallor suggest syncope, whereas cyanosis, tongue biting and a prolonged postictal state favor an epileptic seizure. In cases of doubt or if cardiac syncope is suspected additional diagnostic tests may be necessary. Due to the increased mortality, patients with cardiac syncope need urgent cardiological treatment. The aim of the treatment of vasovagal syncope is to avoid additional events as this type is not associated with increased mortality. This can be achieved by behavioral changes, e.g. avoiding the trigger situation and lying down or tensing of arm and leg musculature during the prodrome to avoid further reduction of blood pressure. There is only sparse evidence for pharmacotherapeutic options. Cardiac pacemakers mostly have no effect. The implantation of a pacemaker seems to be beneficial only in patients over 40 years old with frequent vasovagal syncope, asystole and negative tilt table test.     

Identifying patients with epilepsy at high risk of cardiac death: signs,risk factors and initial management of high risk of cardiac death

People with epilepsy have a three‐fold increased risk of dying prematurely, and a significant proportion is due to sudden cardiac death or acute myocardial infarctions. The causes of increased cardiovascular morbidity and mortality in epilepsy are manifold and include acute or remote effects of epileptic seizures, the longstanding epilepsy itself or antiseizure treatments. Seizure‐related cardiac arrhythmias are common and comprise bradyarrhythmia and asystole, atrial fibrillation and ventricular tachycardia. The most frequent clinically relevant seizure‐related arrhythmia is ictal asystole that may require implantation of a cardiac pacemaker, whereas seizure‐related ventricular tachycardias are only rarely reported. Takotsubo cardiomyopathy and myocardial infarction are rare complications and predominantly described in association with tonic‐clonic seizures. Epilepsy‐related cardiac complications include a disturbed cardiac autonomic nervous system and acquired dysfunction of the heart (recently defined as ‘epileptic heart’), probably contributing to the abnormalities of cardiac repolarisation and elevated risk of sudden cardiac death in people with epilepsy. If successful, the use of antiseizure medication prevents seizure‐related cardiac arrhythmias and remote cardiac complications. However, enzyme‐inducing antiseizure medications have a negative impact on cardiovascular risk factors, which may further be aggravated by weight gain linked to specific antiseizure drugs. Given the severe consequences of cardiac risks, the aim of this educational review is to explain the many facets of cardiac complications and their underlying causes, and to enable the reader to recognize and manage these risks with the goal to mitigate the cardiac risks in people with epilepsy. Features of syncope are explained in detail, as syncope of all origins can be mistaken as epileptic seizures in people with or without epilepsy, and ictal syncope (i.e. seizure‐induced syncope) can easily be ignored.     

Clinical diagnosis of syncopes (including so-called breath-holding spells) without electroencephalography or ocular compression

A recent article in this journal suggested that ocular compression during electroencephalography was useful in distinguishing "breath-holding spells and syncope" from epileptic seizures. The method proposed involved measurement of the RR interval on the simultaneously recorded electrocardiographic trace and determining both the absolute RR lengthening and the change in RR interval as compared with the baseline value. It is argued by the present author that this is not an appropriate way to come to a diagnosis in episodic loss of consciousness in children. It is pointed out that so-called "breath-holding spells" are reflex syncopes and that the diagnosis of reflex syncopes should be by clinical history, even if this means delaying the diagnosis until a future consultation. Published evidence on the nature and clinical diagnosis of reflex syncopes in infants and children is reviewed in depth. It is concluded that routine electroencephalography is not an appropriate investigation when the diagnosis of episodic loss of consciousness is in doubt and has the implicit danger of false positive "abnormality". Aside from scientific exploration of the developing autonomic nervous system, the only current indication for diagnostic ocular compression is to induce a syncope so that its nature may be better understood. Such a circumstance might be a history of an apparent reflex syncope but with atypical features, including prolonged post-syncopal unconsciousness such as might indicate epileptic absence status. Several additional investigations of a primarily cardiological nature may be indicated in some cases, but a wait-and-see policy is usually to be preferred.     

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.     

Compulsive respiratory stereotypies in children with autistic features: Polygraphic recording and treatment with fenfluramine

Syncopes due to compulsive respiratory stereotypies were studied in eight patients with autistic features. Most had been referred for episodes thought to be intractable epileptic seizures. Polygraphic recording showed two types of syncope, one induced by prolonged apnea and the other by a prolonged Valsalva maneuver. Fenfluramine, 1.5–3 mg/kg per day, was given in an open trial. In four of five cases with frequent Valsalva maneuvers, respiratory stereotypies and syncopes were suppressed for 2–18 months. Patients with periodic apneas were more severely retarded and had less clear benefit. Side effects consisted of dose-dependent sedation and mild weight loss which stabilized without interrupting treatment. We suggest that these syncopes are volitional and may be associated with pleasant sensations. A double-blind placebo-controlled trial of fenfluramine seems warranted in such patients.     

Seizures and syncope:

Abstract Although pathophysiologically distinct, syncope and seizures share clinical characteristics which may make diagnosis difficult. Adding to diagnostic complexity are the facts that seizures and syncope may coexist in the same patient, syncope may be associated with seizure-like motor manifestations, and seizures may be complicated by cardiac arrhythmia and syncope. Combined EEG/ECG telemetry is sometimes necessary to establish the correct diagnosis. These techniques also provide an opportunity to study the role of certain cortical regions in the modulation of cardiac function. There is an increasing understanding of the central autonomic pathways involved in the genesis of the cardiovascular changes that occur during epileptic seizures. This article reviews the use of EEG/ECG telemetry in the evaluation of syncope and seizures, and the neuroanatomic circuitry involved in the production of the cardiovascular manifestations of seizures.     

Complex Partial Seizure Provocation by Vasovagal Syncope: Video-EEG and Intracranial Electrode Documentation

Summary: Vasovagal syncope precipitating an epileptic seizure has only rarely been described. A patient with known intractable complex partial seizures being evaluated for a left anterior temporal lobectomy experienced a typical seizure with mesial temporal onset precipitated by an observed vasovagal episode. This is the first report of a partial epileptic seizure precipitated by vasovagal syncope and the first example of an epileptic seizure induced by syncope in an adult. Video and intracranial depth electrode and subdural grid recordings documented the event.     

Autonomic seizures versus syncope in 18q- deletion syndrome: a case report

PURPOSE: The 18q- deletion syndrome (18qDS) is frequently associated with cardiac anomalies. Patients with this syndrome may also have epilepsy, which presents certain diagnostic difficulties. This case report aims to illustrate these diagnostic problems, document the usefulness of heart rate-based seizure detection algorithms in this setting, and define the epilepsy syndrome associated with 18qDS. METHODS: Closed-circuit video electroencephalogram (EEG) monitoring using a heart rate-based seizure detection software was used to identify the event in question and to establish the diagnosis of epilepsy. Chromosomal analysis and magnetic resonance imaging (MRI) were used to further define the epilepsy syndrome. RESULTS: We report on a patient with an atrial septal defect, enlargement of the right heart, and incomplete right bundle branch block, who developed episodes of tachycardia, loss of consciousness, and pallor, for which he was amnesic. Chromosomal analysis demonstrated karyotype 46,XY,del(18)(q21.3). ish del(18)(wcp18+,D18Z1+) with a loss of the gene for myelin basic protein. MRI revealed multifocal dysmyelination. Video-EEG monitoring using an electrocardiogram (ECG)-triggered seizure detection software proved to be indispensable in detecting an autonomic seizure and establishing the correct diagnosis; the procedure also allowed for the definition of the epilepsy syndrome. The patient was treated with carbamazepine and remained seizure-free. CONCLUSIONS: Video-EEG monitoring using a heart rate-based seizure detection software can be helpful in diagnostically differentiating autonomic seizures from syncope. Dysmyelination due to loss of the myelin basic protein gene on 18q and cortical dysgenesis may be of pathogenic relevance.     

Familial mesial temporal lobe epilepsies: Clinical and genetic features

Familial mesial temporal lobe epilepsy (FMTLE) was first described as a benign syndrome with prominent psychic and autonomic seizures and no association with hippocampal sclerosis (HS) or febrile seizures (FS). Better definition of the syndrome allowed identification of more heterogeneous phenotypes with mild to severe epileptic disorders, and a variable association with HS and FS. The genetics of these conditions is largely unknown and the hope for the future is that the identification of FMTLE genes will lead to more appropriate approaches for the diagnosis and treatment of TLE.     

Epileptic seizures in subcortical vascular encephalopathy

Cerebrovascular disease is one of the most common causes of epilepsy in the elderly. Most of the studies published relate to cortical infarction, subarachnoid, and intracranial hemorrhage, whereas the incidence of epilepsy from subcortical ischemia, i.e. deep lacunar infarctions and diffuse white matter lesions, is obscure. Therefore, we prospectively examined 18 patients with the precisely defined diagnosis of subcortical vascular encephalopathy (SVE), who were admitted to our hospital due to epileptic seizures (group A), and compared them to a similarly selected group matched for age, sex, risk factors, and neurological deficits with an equivalent severity of SVE but without seizures (group B). Subcortical lacunar infarctions were significantly more frequent in group A than group B (15/18 versus 4/18, p < 0.001), whereas neither the extension, degree, distribution of periventricular white matter changes, nor the presence of internal hydrocephalus, focal or diffuse cortical atrophy showed any statistical significance. However, a temporal constant theta or delta EEG focus was present in 10/18 patients in group A but only in 1/18 patients from group B (p 0.005). 10/18 patients developed epilepsy with further seizures during follow-up. The association of SVE, multiple subcortical lacunas, and temporal EEG abnormalities are suggestive for an increased risk for epileptic seizures, which is particularly important for the treatment of patients with SVE if uncertain paroxysmal episodes occur, e.g. transient ischemic attacks, seizures, or cardiac syncope.     

Unilateral mydriasis during temporal lobe seizures.

Autonomic signs and symptoms are a common feature of epileptic seizures. Although sympathetic activation responses are predominant, we can also find sympathetic inhibition and even an activation of the parasympathetic division of the autonomic nervous system, especially in partial seizures. These autonomic symptoms during seizures are thought to be the result of neuronal discharges arising from or spreading to cortical areas of the central autonomic network. Mydriasis, most commonly bilateral, is one of the most frequent findings. The patient described, a middle-aged man with a focal lesion in the right temporal lobe extended to the adjacent hypothalamus, presented with episodes of autonomic symptoms including prominent unilateral mydriasis, finally evolving into a state of decreased alertness. An ictal electroencephalogram and a simultaneous video recording supported the clinical impression of an epileptic aetiology. Unilateral mydriasis is a rare condition during epileptic seizures and very few cases have been reported in the past.     

Atrial fibrillation associated with epileptic seizures

BACKGROUND Epileptic seizures are often associated with changes in cardiac autonomic function. Yet atrial fibrillation (AFib) or atrial flutter (AFlu) following epileptic seizures has only rarely been reported in the past. OBJECTIVES To describe and characterize patients who experienced lone AFib or AFlu as a consequence of epileptic seizures. DESIGN Case reports. SETTING University teaching hospital. PATIENTS We describe 4 patients who developed transient AFib following epileptic seizures and 1 patient who developed transient AFlu following epileptic seizures. RESULTS In all patients, AFib and AFlu followed a generalized tonic-clonic seizure. The arrhythmia usually lasted a few hours and converted spontaneously to a normal sinus rhythm. In 3 patients, AFib or AFlu developed during the first seizure they experienced, and none of the patients developed drug-resistant epilepsy. Moreover, none of the patients had a known cardiac disease, yet, in 2 patients, the cardiological workup demonstrated mild abnormalities on the cardiac stress test. CONCLUSIONS Atrial fibrillation is the most common type of arrhythmia, with an estimated prevalence of 1%. Despite the fact that AFib can cause syncope, it is important to consider the possibility of AFib developing secondary to an epileptic seizure in cases of AFib and transient loss of consciousness.     

Panayiotopoulos syndrome: diagnosis and management

Abstract Panayiotopoulos syndrome is a relatively frequent and benign epileptic syndrome, characterised by predominantly autonomic symptoms and/or simple motor focal seizures followed or not by impairment of consciousness. Interictal EEG shows occipital spikes although multifocal spikes with high amplitude sharp-slow wave complexes at various locations can be present. This syndrome can imitate gastroenteritis, encephalitis, syncope, migraine, sleep disorders or metabolic diseases. The peculiar aspects should be known not only by epileptologists but also by general doctors because a correct diagnosis would avoid aggressive interventions and concerns on account of its benign outcome. This review focuses on the main clinical and EEG features of this epilepsy underlining its typical and atypical symptoms and its management.     

Long-QT-Syndrom als Differenzialdiagnose einer Grand-Mal-Epilepsie

A 24-year-old female with a history of epileptic seizures was admitted after prolonged cardiac resuscitation. The clinical course together with additional examinations led to the diagnosis of severe hypoxic cerebral damage, with poor prognosis for neurological outcome. In her initial ECG, as in the ECGs of several family members, QT prolongation was diagnosed. Meticulous history taking and ensuing genetic analysis led to the diagnosis of familial long QT syndrome (LQTS) with a mutation in the LQT-2 gene (HERG). In retrospect, the previous seizure episodes have to be considered cardiac syncopes. Two family members had previously died suddenly, and ECG and genetic analysis revealed that a total of eight family members were affected. These relatives were prophylactically treated with beta blockers or supplied with automated implantable cardioverter defibrillating devices. The literature concerning LQTS, diagnosis and prognosis of cerebral hypoxic damage, and differentiation between seizures and cardiac syncopes is discussed.     

Dreaming experience as a useful diagnostic clue for syncopal episodes

Background: The differential diagnosis between epileptic seizures and syncopes is a common occurrence in clinical practice. The manifestations of seizure and syncope sometimes overlap, and available diagnostic testing often not provides a conclusive answer. Syncope is often preceded by a symptom complex characterized by lightheadedness, generalized muscle weakness, giddiness, visual blurring, tinnitus, and gastrointestinal symptoms. These subjective symptoms are very important in guiding the diagnosis. In our experience, the impression of coming out of a dream after the syncopal episode is a subjective symptom commonly reported by patients, if questioned. Methods: To verify the occurrence of dreaming experience after syncope and after generalized tonic‐clonic seizures (GTCS) and its diagnostic value in differential diagnosis, we asked 100 patients with GTCS and diagnosis of idiopathic generalized epilepsy (Group 1) and 100 patients with a certain diagnosis of syncope (Group 2) whether they have never felt the impression of coming out of a dream after the loss of consciousness (GTCS or syncope, respectively). Results: In Group 1, nobody referred the dreaming experience, whereas in the syncope group, 19% of patients referred this subjective symptom. Conclusions: Dreaming experience seems to be an additional useful diagnostic clue for syncopal episodes, helping the clinician to differentiate them from seizures.     

Self-induced stretch syncope of adolescence: a video-EEG documentation.

We present the first video-EEG documentation, with ECG and EMG features, of stretch syncope of adolescence in a young, healthy 16-year-old boy. Stretch syncope of adolescence is a rarely reported, benign cause of fainting in young patients, which can be confused with epileptic seizures. In our patient, syncopes were self-induced to avoid school. Dynamic transcranial Doppler showed evidence of blood flow decrease in both posterior cerebral arteries mimicking effects of a Valsalva manoeuvre. Dynamic angiogram of the vertebral arteries was normal. Hypotheses concerning the physiopathology are discussed. [Published with video sequences].     

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].     

Epilepsy and autonomic diseases

This review article focuses on the functional anatomy of the central autonomic nervous system and the autonomic symptoms and dysfunctions occurring with epileptogenic activity involving areas of the central autonomic nervous system. Clinical experiences have demonstrated a close relation between epileptic and central autonomic activity. Autonomic symptoms are frequent signs of epileptic seizures and may cause dysfunctions in almost every organ system. Cardiorespiratory dysfunction has been described interictually. The increased frequency of sudden unexplained death in epilepsy patients may be related to disturbances in cardiac autonomic control. In contrast, electrical vagal stimulation reduces epileptogenic activity by influencing the central autonomic nervous system.     

Ictal video-polysomnography and EEG spectral analysis in a child with severe Panayiotopoulos syndrome.

OBJECTIVE: To describe the ictal polysomnographic features of a patient with Panayiotopoulos syndrome, a peculiar epileptic syndrome characterized by infrequent, often single, prolonged, nocturnal, focal seizures comprising an unusual constellation of autonomic symptoms (malaise, nausea, pallor, tachycardia, vomiting) and unilateral deviation of the eyes at the onset of seizures. These clinical, ictal manifestations are rarely followed by post-ictal headache. In the literature, there is little information on the ictal EEG characteristics of Panayiotopoulos syndrome and, in particular, on certain autonomic manifestations, such as tachycardia, as the sole ictal phenomena at the onset of seizures. METHODS AND RESULTS: One, all-night videopolysomnography, during which one seizure was recorded. Video-EEG data were evaluated visually and by means of quantitative spectral analysis. The spectral analysis of the recorded seizure showed a complex ictal pattern of cortical involvement with focal onset in the right occipital area followed by the recruitment of widespread extra-occipital cortical regions. CONCLUSIONS: This is the first such analysis of this peculiar epileptic condition. Most of the symptoms were consistent with a diagnosis of severe Panayiotopoulos syndrome, although the patient also presented "atypical findings": a relatively high frequency of seizures, post-ictal headache, no spontaneous remission of seizures with age, and late onset of visual hallucinations; this last finding is more frequent in "Gastaut-type childhood occipital epilepsy", in which onset typically occurs later than in Panayiotopoulos syndrome. [Published with video sequences].