Seizure versus syncope

Seizure or syncope: Is the history-based scale feasible to use in an emergency department setting?

BACKGROUND

This study aimed to assess the efficacy of a screening questionnaire, based on historical criteria, in distinguishing between seizures and syncope in patients experiencing their first episode of transient loss of consciousness (TLOC) in a neurology emergency department.

METHODS

A prospective cohort of 159 patients with initial TLOC episodes underwent clinical observation and answered a nine-question screening questionnaire. The questionnaire's predictive ability was compared to final diagnoses determined through detailed neurology, electrophysiology, and cardiology assessments during a minimum 12-month follow-up. Logistic regression (LR) analysis was performed with final diagnosis as the outcome variable. The calibration and discrimination of the models were assessed.

RESULTS

revealed that the screening score accurately classified 72.33% of patients. Among those with positive screening scores, 65 (67.71%) had seizures compared to 31 (32.29%) with syncope. Introducing a novel risk-scoring model incorporating age and gender, in addition to the screening score, significantly improved performance achieving an accurate classification rate of 81.48%. Among patients with a positive prediction, 63 (80.77%) had seizure, whereas 15 (19.23%) had syncope.

CONCLUSIONS

Employing a structured questionnaire based on common historical criteria is a valuable tool for distinguishing between seizure and syncope in the dynamic setting of the emergency department.

Convulsive Syncope as a Complication of Outpatient Procedures: A Case Series and Review of the Literature

ABSTRACT

Sports medicine providers often perform various outpatient procedures to manage musculoskeletal and neuropathic conditions. Vasovagal syncope is a rare but a possible complication. Convulsive syncope is one subtype that involves brief extensor stiffening and nonsustained myoclonus and can be easily mistaken for seizures. We present a case series of convulsive syncope as a complication of common sports medicine outpatient procedures. We aim to describe how to identify this condition, and offer risk stratification and management strategies to mitigate the risks of this complication. Sports medicine providers who routinely practice outpatient procedures should be aware of this complication. Simple changes in approaching the procedure may mitigate these risks. High- and intermediate-risk features of the syncopal episode should prompt physicians to seek further evaluation by a specialist to rule out more serious conditions. In all instances, appropriate on-site support and equipment for emergent resuscitation and management should be prepared.

Distinguishing Convulsive Syncope From Seizure Induced by Repetitive Transcranial Magnetic Stimulation: A Case Report

ABSTRACT

Repetitive transcranial magnetic stimulation (rTMS) is Food and Drug Administration cleared for clinical use in treatment-resistant depression and a growing list of other disorders. The clinical uptake of rTMS has been facilitated by its relatively benign adverse-effect profile compared with other treatment modalities. Seizure is a rare but serious adverse event that has been reported with rTMS, when dosage exceeds safety guidelines or in individuals at increased risk for seizure. Fortunately, most rTMS-induced seizures are typically transient, with no adverse sequelae, but they may lead to treatment discontinuation. Seizure is not the only cause of loss of conscious and abnormal movements induced by rTMS. Convulsive syncope, a more common adverse event that involves loss of consciousness associated with myoclonic movements, can be difficult to differentiate from an rTMS-induced seizure. We report the case of a 52-year-old man with no known seizure risk factors, enrolled in an institutional review board-approved research study who developed what appeared to be a convulsive syncopal episode lasting 10 to 15 seconds during day 2 of a 30-day rTMS protocol (10 Hz, 120% of motor threshold, 4-second pulse train, 26-second intertrain interval, 3000 pulses per session), with no adverse sequelae. The patient's history, screening, physical examination, pertinent laboratory, neurology consult, electroencephalogram, and imaging findings are discussed. This case demonstrates that distinguishing between convulsive syncope and rTMS-induced seizure can be a diagnostic challenge. Clinicians and researchers delivering rTMS should be familiar with the risk factors for rTMS-induced seizures and rTMS-induced convulsive syncope, to screen for predisposing factors and to manage these rare adverse events if they occur.

Epileptic Seizure Induced by Head-Up Tilt: A Case Series Study

PURPOSE

Epilepsy and syncope can be difficult to distinguish, with misdiagnosis resulting in unnecessary or incorrect treatment and disability. Combined tilt-table and video EEG (vEEG) testing (tilt-vEEG) is infrequently used to parse these entities even at large centers. Because of the discovery of a rare case of epileptic seizure induced by head-up tilt (HUT) (no prior cases have been published), the authors sought to verify the rarity of this phenomenon.

METHODS

An observational, retrospective case series study of all combined tilt-vEEG studies performed at Stanford Health Care over a 2-year period was performed. Studies were grouped into categories: (1) abnormal tilt and normal vEEG; (2) abnormal vEEG and normal tilt; (3) abnormal vEEG and abnormal tilt; (4) normal tilt and normal vEEG, with neurologic symptoms; and (5) normal tilt and normal vEEG without neurologic symptoms.

RESULTS

Sixty-eight percent of patients had an abnormal study (categories A-C), with only 3% having both an abnormal tilt and an abnormal EEG (category C). Of these, one patient had a focal epileptic seizure induced by HUT. With HUT positioning, the patient stopped answering questions and vEEG showed a left temporal seizure; systolic blood pressure abruptly dropped to 89 mm Hg (64 mm Hg below baseline); heart rate did not change, but pacemaker showed increased firing (threshold: <60 bpm).

CONCLUSIONS

Combined tilt-table and vEEG evaluation was able to identify a previously unreported scenario-head-up tilt provocation of an epileptic seizure-and improve treatment. Combined tilt and vEEG testing should be considered for episodes that persist despite treatment to confirm proper diagnosis.

Sub-Scalp Implantable Telemetric EEG (SITE) for the Management of Neurological and Behavioral Disorders beyond Epilepsy

Sub-scalp Implantable Telemetric EEG (SITE) devices are under development for the treatment of epilepsy. However, beyond epilepsy, continuous EEG analysis could revolutionize the management of patients suffering from all types of brain disorders. This article reviews decades of foundational EEG research, collected from short-term routine EEG studies of common neurological and behavioral disorders, that may guide future SITE management and research. Established quantitative EEG methods, like spectral EEG power density calculation combined with state-of-the-art machine learning techniques applied to SITE data, can identify new EEG biomarkers of neurological disease. From distinguishing syncopal events from seizures to predicting the risk of dementia, SITE-derived EEG biomarkers can provide clinicians with real-time information about diagnosis, treatment response, and disease progression.

Classification Model for Epileptic Seizure Using Simple Postictal Laboratory Indices

Distinguishing syncope from epileptic seizures in patients with sudden loss of consciousness is important. Various blood tests have been used to indicate epileptic seizures in patients with impaired consciousness. This retrospective study aimed to predict the diagnosis of epilepsy in patients with transient loss of consciousness using the initial blood test results. A seizure classification model was constructed using logistic regression, and predictors were selected from a cohort of 260 patients using domain knowledge and statistical methods. The study defined the diagnosis of seizures and syncope based on the consistency of the diagnosis made by an emergency medicine specialist at the first visit to the emergency room and the diagnosis made by an epileptologist or cardiologist at the first outpatient visit using the International Classification of Diseases 10th revision (ICD-10) code. Univariate analysis showed higher levels of white blood cells, red blood cells, hemoglobin, hematocrit, delta neutrophil index, creatinine kinase, and ammonia levels in the seizure group. The ammonia level had the highest correlation with the diagnosis of epileptic seizures in the prediction model. Therefore, it is recommended to be included in the first examination at the emergency room.

A rare case of drug sensitive adult‐onset temporal lobe epilepsy due to a focal cortical dysplasia revealed by ictal coughing: First report in sub‐Saharan Africa

This case suggests that clinicians should consider seizures as a differential diagnosis of paroxystic cough with loss of consciousness. Focal cortical dysplasia should equally be screened for with magnetic resonance imaging (MRI) scans even in adults with epilepsy in sub‐Saharan Africa.

This case suggests that clinicians should consider seizures as a differential diagnosis of paroxystic cough with loss of consciousness. Focal cortical dysplasia should equally be screened for with Magnetic Resonance Imaging (MRI) scans even in adults with epilepsy in sub‐Saharan Africa.

Unmasking of Brugada syndrome by lamotrigine in a patient with pre-existing epilepsy: A case report with review of the literature

Brugada syndrome is an inherited cardiac channelopathy arising from mutations in voltage-gated cardiac sodium channels. Idiopathic epilepsy portrays a coalescent underlying pathophysiological mechanism pertaining to the premature excitation of neuronal voltage-gated ion channels resulting in the disruption of presynaptic neurons and the unregulated release of excitatory neurotransmitters. The coexistence of epilepsy and Brugada syndrome may be explained by mutations in voltage-gated ion channels, which are coexpressed in cardiac and neural tissue. Moreover, the incidence of sudden unexpected death in epilepsy has been associated with malignant cardiac arrhythmias in the presence of mutations in voltage-gated ion channels. Lamotrigine is an antiepileptic drug that inhibits neuronal voltage-gated sodium channels, thus stabilizing neural impulse propagation and controlling seizure activity in the brain. However, lamotrigine has been shown to inhibit cardiac voltage-gated sodium channels resulting in a potential arrhythmogenic effect and the ability to unmask Brugada syndrome in genetically susceptible individuals. We are reporting a case of a 27-year-old male patient with a background of presumed idiopathic epilepsy who was initiated on lamotrigine therapy resulting in the unmasking of Brugada syndrome and the onset of syncopal episodes. This case provides further evidence for the arrhythmogenic capacity of lamotrigine and highlights the relationship between epilepsy and Brugada syndrome. In this report, we aim to review the current literature regarding the associations between epilepsy and Brugada syndrome and the impact of lamotrigine therapy on such patients.

The ability of Canadian Syncope risk score in differentiating cardiogenic and non-cardiogenic syncope; a cross-sectional study

INTRODUCTION

Determining the underlying etiology of syncope provides valuable prognostic information and expedites the implementation of a therapeutic strategy. This study aimed to evaluate the ability of Canadian Syncope Risk Score (CSRS) in differentiating cardiogenic and non-cardiac syncope.

METHODS

The present diagnostic accuracy study was conducted on adult patients with syncope, who presented to the emergency departments of Shohadaye Tajrish and Imam Hossein Hospitals in Tehran from March 2018 to March 2019. The data required for determining CSRS were collected during the initial assessment and the underlying etiology was confirmed through further diagnostic follow-up under the supervision of a cardiologist or neurologist. Finally, the screening performance characteristics of the score were calculated.

RESULTS

300 patients with the mean age of 56.38 ± 19.10 years were studied. The source of syncope was cardiac in 133 (44.3%) and non-cardiac in 137 (55.7%) patients. The area under the ROC curve of CSRS in differentiating cardiac syncope was 0.77 (95% CI: 0.715-0.824). At a cutoff point of -1.5, the sensitivity and specificity of the score were calculated to be 73.68% (95% CI: 65.21-80.75%) and 73.05% (95%CI: 75.54-79.47%), respectively.

CONCLUSION

The present study reveals that CSRS has fair accuracy in differentiating the source of syncope and has no superiority over a clinical examination. Therefore, we do not recommend relying on the CSRS to differentiate between cardiac and non-cardiac syncope alone.

Brugada Syndrome: Warning of a Systemic Condition?

Brugada syndrome (BrS) is a hereditary disorder, characterized by a specific electrocardiogram pattern and highly related to an increased risk of sudden cardiac death. BrS has been associated with other cardiac and non-cardiac pathologies, probably because of protein expression shared by the heart and other tissue types. In fact, the most commonly found mutated gene in BrS, SCN5A, is expressed throughout nearly the entire body. Consistent with this, large meals and alcohol consumption can trigger arrhythmic events in patients with BrS, suggesting a role for organs involved in the digestive and metabolic pathways. Ajmaline, a drug used to diagnose BrS, can have side effects on non-cardiac tissues, such as the liver, further supporting the idea of a role for organs involved in the digestive and metabolic pathways in BrS. The BrS electrocardiogram (ECG) sign has been associated with neural, digestive, and metabolic pathways, and potential biomarkers for BrS have been found in the serum or plasma. Here, we review the known associations between BrS and various organ systems, and demonstrate support for the hypothesis that BrS is not only a cardiac disorder, but rather a systemic one that affects virtually the whole body. Any time that the BrS ECG sign is found, it should be considered not a single disease, but rather the final step in any number of pathways that ultimately threaten the patient's life. A multi-omics approach would be appropriate to study this syndrome, including genetics, epigenomics, transcriptomics, proteomics, metabolomics, lipidomics, and glycomics, resulting eventually in a biomarker for BrS and the ability to diagnose this syndrome using a minimally invasive blood test, avoiding the risk associated with ajmaline testing.

Can Dyssynergia of Vestibulosympathetic and Baroreflexes Cause Vestibular Syncope? The Hypothesis Based on the Velocity-Storage Function

The mechanism of vestibular syncope, the syncope occurring during the vertigo attacks, remains uncertain. This study aims to clarify the mechanism of vestibular syncope by pursuing the function of vestibular system in cardiovascular autonomic control and by defining neuro-hemodynamic changes in vestibular syncope. By integrating the velocity-storage (VS) circuit in the brainstem and cerebellum, we propose that the vestibular syncope develops as a result of dyssynergia of the vestibulosympathetic and baroreflexes in which centrally estimated downward inertial acceleration during the vertigo attacks acts as a trigger. Recognition of the vestibular disorders as a possible cause of syncope would allow proper managements for prevention of further syncope and related complications in patients with vestibular disorders.

Functional hyperactivity in long QT syndrome type 1 pluripotent stem cell-derived sympathetic neurons

Sympathetic activation is an established trigger of life-threatening cardiac events in long QT syndrome type 1 (LQT1). KCNQ1 loss-of-function variants, which underlie LQT1, have been associated with both cardiac arrhythmia and neuronal hyperactivity pathologies. However, the LQT1 sympathetic neuronal phenotype is unknown. Here, we aimed to study human induced pluripotent stem cell (hiPSC)-derived sympathetic neurons (SNs) to evaluate neuronal functional phenotype in LQT1. We generated hiPSC-SNs from two patients with LQT1 with a history of sympathetically triggered arrhythmia and KCNQ1 loss-of-function genotypes (c.781_782delinsTC and p.S349W/p.R518X). Characterization of hiPSC-SNs was performed using immunohistochemistry, enzyme-linked immunosorbent assay, and whole cell patch clamp electrophysiology, and functional LQT1 hiPSC-SN phenotypes compared with healthy control (WT) hiPSC-SNs. hiPSC-SNs stained positive for tyrosine hydroxylase, peripherin, KCNQ1, and secreted norepinephrine. hiPSC-SNs at 60 ± 2.2 days in vitro had healthy resting membrane potentials (-60 ± 1.3 mV), and fired rapid action potentials with mature kinetics in response to stimulation. Significant hyperactivity in LQT1 hiPSC-SNs was evident via increased norepinephrine release, increased spontaneous action potential frequency, increased total inward current density, and reduced afterhyperpolarization, compared with age-matched WT hiPSC-SNs. A significantly higher action potential frequency upon current injection and larger synaptic current amplitudes in compound heterozygous p.S349W/p.R518X hiPSC-SNs compared with heterozygous c.781_782delinsTC hiPSC-SNs was also observed, suggesting a potential genotype-phenotype correlation. Together, our data reveal increased neurotransmission and excitability in heterozygous and compound heterozygous patient-derived LQT1 sympathetic neurons, suggesting that the cellular arrhythmogenic potential in LQT1 is not restricted to cardiomyocytes.NEW & NOTEWORTHY Here, we present the first study of patient-derived LQT1 sympathetic neurons that are norepinephrine secreting, and electrophysiologically functional, in vitro. Our data reveal a novel LQT1 sympathetic neuronal phenotype of increased neurotransmission and excitability. The identified sympathetic neuronal hyperactivity phenotype is of particular relevance as it could contribute to the mechanisms underlying sympathetically triggered arrhythmia in LQT1.

Adverse Drug Reactions of Antiepileptic Drugs in the Neurology Department of a Tertiary Care Hospital, Srinagar, Jammu & Kashmir, India

Background: Epilepsy is a disorder that affects 1% of the global population. It is the second most common serious neurologic disorder after stroke, affecting humans. Since antiepileptic drugs have a narrow therapeutic index and their adverse effects can affect any organ, their widespread use has significant safety implications. Objectives: The study assessed adverse drug reactions (ADRs) using antiepileptic drugs in the Department of Neurology at a Tertiary Care Hospital, Srinagar, Jammu & Kashmir, India. Methods: This prospective observational study was conducted in the Department of Neurology of a Tertiary Care Hospital, Srinagar, Jammu & Kashmir, India, for eight months. It was a spontaneous reporting of ADRs by practicing physicians in the outpatient and inpatient settings that were included in the study. Results: Of the 3,300 patients who were on the anti-epileptic drug (AED), 92 (3.07%) had AED-related ADRs. A total of 18 cases were reported in the inpatient department and 74 cases in the outpatient setting. The most common ADRs were loss of appetite (34.78%), skin rashes (17.39%), and gum hypertrophy (9.78%). Of 80 ADRs, 42.5% were related to valproate, followed by phenytoin, carbamazepine, and levetiracetam. The suspected drug was changed in 22 patients with ADRs. Conclusions: For the early diagnosis and avoidance of ADRs, the frequent follow-up of patients on AEDs is needed to improve patient compliance with drug therapy and provide better drug therapy for avoiding associated morbidity and mortality.

Long-term Home Video EEG for Recording Clinical Events

SUMMARY

Around 50 years after the first EEG acquisition by Hans Berger, its use in ambulatory setting was demonstrated. Ever since, ambulatory EEG has been widely available and routinely used in the United States (and to a lesser extent in Europe) for diagnosis and management of patients with epilepsy. This technology alone cannot help with semiological characterization, and absence of video is one of its main drawbacks. Addition of video to ambulatory EEG potentially improves diagnostic yield and opens new aspects of utility for better characterization of patient's events, including differential diagnosis, classification, and quantification of seizure burden. Studies evaluating quality of ambulatory video EEG (aVEEG) suggest good quality recordings are feasible. In the utilization of aVEEG, to maximize yield, it is important to consider pretest probability. Having clear pretest questions and a strong index of suspicion for focal, generalized convulsive or non-epileptic seizures further increases the usefulness of aVEEG. In this article, which is part of the topical issue "Ambulatory EEG," the authors compare long-term home aVEEG to inpatient video EEG monitoring, discuss aVEEG's use in diagnosis and follow-up of patients, and present the authors' own experience of the utility of aVEEG in a teaching hospital setting.

Safety Review for Clinical Application of Repetitive Transcranial Magnetic Stimulation

Studies using repetitive transcranial magnetic stimulation (rTMS) in healthy individuals and those with neuropsychiatric diseases have rapidly increased since the 1990s, due to the potential of rTMS to modulate the cortical excitability in the brain depending on the stimulation parameters; therefore, the safety considerations for rTMS use are expected to become more important. Wassermann published the first safety guidelines for rTMS from the consensus conference held in 1996, and Rossi and colleague then published the second safety guidelines from the multidisciplinary consensus meeting held in Siena, Italy in 2008, on behalf of the International Federation of Clinical Neurophysiology. More than 10 years after the second guidelines, the updated third safety guidelines were recently published in 2021. The general safety guidelines for conventional rTMS have not substantially changed. Because the most frequently used rTMS protocol is conventional (low- and high-frequency) rTMS in research and clinical settings, we focus on reviewing safety issues when applying conventional rTMS with a focal cortical stimulation coil. The following issues will be covered: 1) possible adverse events induced by rTMS; 2) checklists to screen for any precautions and risks before rTMS; 3) safety considerations for dosing conventional rTMS; and 4) safety considerations for using rTMS in stroke and traumatic brain injury.

Ictal asystole during long-term video-EEG; semiology, localization, and intervention

Ictal arrhythmias are disturbances of cardiac conduction that occur during clinical or electrographic seizures. Ictal asystole (IA) is rare, and its incidence can range from 0.3–0.4% in patients with epilepsy who were monitored by video-EEG (van der Lende et al., 2015).

We report on ten patients (six males and four females) with an age ranging from 31 to 70 years old) who were monitored in our video-EEG (VEEG) unit over the last eight years. These patients were selected based on the history of documented ictal asystole during inpatient VEEG monitoring). In our series the mean latency from the seizure onset to the onset of ictal asystole was 22 seconds and the mean duration of the IA was 15.8 seconds. During the asystolic phase the seizures may clinically continue or syncopal signs may supervene.

In our case series all the patients had either left or right temporal lobe epilepsy, six of which were lesional. We found two patterns of ictal semiology in our series. The first group of patients included five patients who experienced a rapid onset of IA in their seizure and the second group where the latency of ictal asystole was relatively late. All our cohort had a permanent pacemaker following the diagnosis, six of these patients have been event free since placement.

Children with transient loss of consciousness: Clinical characteristics and the effectiveness of diagnostic tests

BACKGROUND

Transient loss of consciousness (TLOC) is common among children and adolescents. The aims of this study were to identify clinical differences between patients with vasovagal syncope and those with epileptic seizures, which account for a large proportion of TLOC cases, and to evaluate the effectiveness of various diagnostic tests.

METHODS

The medical records of 160 children and adolescents with TLOC were analyzed retrospectively, and age, sex, clinical symptoms, and trigger factors were recorded. The cardiological and neurological evaluations performed included electrocardiograms, computed tomography scanning, magnetic resonance imaging, electroencephalograms (EEGs), echocardiograms, and head-up tilt tests (HUTTs). Overall assessments of the 160 patients generated final diagnoses.

RESULTS

The mean age of patients was 14.6 years old and TLOC occurred more frequently among girls (59.4%). The most common final diagnosis was vasovagal syncope (n = 102, 63.4%), followed by undetermined (n = 21, 13.1%) and epileptic seizures (n = 17, 10.6%). There were many other diagnoses, including cardiogenic syncope (1.3%). Patients diagnosed with vasovagal syncope were much more likely to have dizziness or light-headedness and blurred vision as pre-symptoms (p < 0.05), whereas patients diagnosed with epileptic seizures were more likely to have convulsions as an accompanying sign (p < 0.05). In addition, standing up was the most significant trigger factor for TLOC among those diagnosed with vasovagal syncope (p < 0.05). The sensitivity, specificity, and accuracy of the HUTT for vasovagal syncope were 95.1%, 75.0%, and 91.8%, respectively. Similarly, the sensitivity, specificity, and accuracy of EEGs for epileptic seizures were 80.0%, 70.6%, and 80.0%, respectively.

CONCLUSION

Vasovagal syncope and epileptic seizures should be considered as possible causes of most cases of TLOC in children and adolescents. An accurate case history and appropriate evaluation are essential for correct diagnoses.

[Convulsive syncope then convulsive seizure occurred in the long clinical course: a case report]

A 17-year-old woman presented with transient consciousness impairment attack and convulsion after bathing and prolonged standing since age 12. EEG showed WHAM ( wake, high amplitude, anterior, male) type of phantom spikes that usually carry the high risk of epilepsy at age 13. At age 17, EEG wise generalized spike and wave complex was recorded once, and head-up tilt test was positive. She was carefully observed without antiepileptic drugs since convulsive syncope due to neurally mediated syncope was most likely. During the follow-up period, she had eventually unprovoked generalized tonic-clonic seizures (convulsive seizure) twice and thus she was started with antiepileptic drug with success. Although both convulsive syncope and convulsive seizure differ in nature and effects on quality of life, in this patient, the latter occurred later and both occurs together. It is important to distinguish them by means of the degree of convulsion and EEG finding.

An Elderly Woman With Recurrent Transient Loss of Consciousness Preceded by Hallucinatory Attacks

We report a patient with transient loss of consciousness preceded by hallucinations caused by cardiac syncope. The diagnosis was confirmed by simultaneous video-electrocardiogram-electroencephalogram recording of an event. The attacks no longer occurred after pacemaker implantation. Clinical features helpful in guiding decision making in transient loss of consciousness are discussed. (Level of Difficulty: Beginner.)

The value of serum uric acid levels to differentiate causes of transient loss of consciousness

BACKGROUND

Generalized tonic-clonic seizures (GTCS), syncope, and psychogenic nonepileptic seizures (PNES) are common emergent neurological conditions that cause transient disturbances of consciousness; however, it is sometimes difficult to distinguish them.

OBJECTIVE

This study aimed to explore the value of serum uric acid levels in differentiating among GTCS, syncope, and PNES by analyzing serum uric acid levels in patients with GTCS, syncope, and PNES.

METHODS

A total of 391 patients were retrospectively analyzed. Venous blood was drawn from the patients within 20 min of their arrival to the emergency department; serum uric acid levels were measured using the uricase method.

RESULTS

Serum uric acid levels and the percentage of patients with elevated uric acid (elevation percentage) were significantly higher in the group with GTCS (n = 179) than in the groups with syncope (n = 156) (p < 0.001) and PNES (n = 56) (p < 0.001). The result remained the same when the serum uric acid level of male or female patients in the group with GTCS were compared separately with that in the other two groups (all p < 0.001). In the group with GTCS, both the serum uric acid level (p < 0.001) and elevation percentage (p < 0.05) were significantly higher in males than in females. The receiver operating characteristics (ROC) analysis in male patients yielded a serum uric acid value of 428.50 μmol/L with a sensitivity of 0.78 and a specificity of 0.99 as the optimal cutoff value to distinguish GTCS from other events. In female patients, a cutoff value of 338.00 μmol/L had a sensitivity of 0.69 and a specificity of 0.91 to distinguish GTCS from other events. For the group with GTCS, the period of time between the onset of seizure and serum uric acid levels dropping to normal were analyzed in 40 patients. The duration was 44.56 ± 11.46 h for males (n = 23) and 40.37 ± 9.78 h for females (n = 17) with no significant difference (p = 0.325).

CONCLUSION

Serum uric acid levels provided certain clinical value for the differentiation of GTCS, syncope, and PNES; however, this requires verification in prospective studies with larger sample sizes.

A case of near-sudden unexpected death in epilepsy due to ventricular fibrillation

Sudden unexpected death in epilepsy (SUDEP) refers to the sudden and unexpected death of an epileptic patient with no other health issues, during normal activity, and for whom no other particular cause of death can be found. The exact cause of SUDEP has not been established yet; however, it is assumed to be caused by multiple organ failure involving the respiratory and cardiovascular systems. Some of the known risk factors are generalized tonic-clonic seizure, frequent epileptic seizure, early onset of epilepsy, long duration of seizure, nocturnal seizure, and combined therapy with antiepileptics. A number of seizure-related cardiac arrhythmia cases have been reported. Arrhythmias are mostly benign tachycardia or bradycardia, and ventricular fibrillation (VF) or asystole is very rare. It is considered that fatal cardiac arrhythmia is a cause of SUDEP. Here, we describe the case of a near-SUDEP patient who was successfully revived without complications by immediate defibrillation with an automated external defibrillator and cardiopulmonary resuscitation, although VF occurred after a convulsive seizure. Based on our experience, when treating a patient with an epileptic seizure, one should always keep in mind the possibility of SUDEP as a seizure-induced emergency situation involving fatal arrhythmia and cardiac arrest, even in young healthy adults.

Delayed diagnosis of long QT syndrome in a patient with seizures

Introduction:

Long QT syndrome accompanied by a seizure episode is often misdiagnosed as primary epilepsy. Although patients with Long QT syndrome who are misdiagnosed and improperly managed are likely to result in fatality, their first clinical manifestations are seizure episodes in many cases.

Case presentation:

A 17-year-old boy visited the emergency department with poorly controlled seizure during epilepsy treatment was found to have been misdiagnosed with epilepsy when he was 7 years old. His electrocardiography showed a prolonged QT interval. After careful re-evaluation, he was finally diagnosed with Long QT syndrome and recovered without any seizure episodes in the absence of anti-epileptic agents.

Discussion and conclusion:

Careful initial assessment including repetitive electrocardiography, when abnormal, is required for those who visit the emergency department with a seizure or who show no definite abnormalities in diagnostic work up process.

Usefulness of head-up tilt test combined with video electroencephalogram to investigate recurrent unexplained atypical transient loss of consciousness

BACKGROUND

Convulsive syncope and epileptic seizure share many similar clinical features. Early diagnosis is critical for choosing the appropriate management strategy.

AIM

Our aim was to evaluate the diagnostic yield of an innovative diagnostic strategy - combined head-up tilt test (HUT)/video electroencephalogram (EEG) monitoring - in patients with unexplained seizure-like transient loss of consciousness (T-LOC).

METHODS

Combined HUT/video EEG was performed in patients with unexplained atypical T-LOC with both syncope and seizure characteristics remaining undiagnosed after a first-line investigation. T-LOC diagnosis was achieved in case of reproduction of usual symptoms. Events were classified as vasovagal, psychogenic or epilepsy. The link between EEG abnormalities and T-LOC was determined by an epilepsy specialist. Clinical follow-up was performed to assess T-LOC recurrence.

RESULTS

Hundred and one consecutive patients were prospectively enrolled (median age 26 [19; 46] years; 72% female) and underwent combined HUT/video EEG between 2007 and 2015. Antiepileptic drugs were being prescribed in 42% of patients. Combined HUT/video EEG was diagnostic in 67% of patients, leading to diagnosis of vasovagal syncope in 59 patients and psychogenic pseudosyncope in nine cases. Antiepileptic drugs were discontinued in 18 patients without epilepsy. Independent predictors of a definitive diagnosis were the presence of prodromal symptoms (odds ratio 5.97, 95% confidence interval 1.37-26; P=0.017) and a history of myoclonic jerks during T-LOC (odds ratio 4.36, 95% confidence interval 1.71-11.15; P=0.002).

CONCLUSIONS

Combined HUT/video EEG is useful for investigating recurrent unexplained atypical seizure-like T-LOC, especially in patients with a history of myoclonic jerks or with documented interictal non-specific EEG abnormalities.

Value of clinical features to differentiate refractory epilepsy from mimics: a prospective longitudinal cohort study

BACKGROUND AND PURPOSE

Misdiagnosis of refractory epilepsy (rE) is common and such patients experience a long diagnostic delay. Our aim was to identify key clinical/laboratory factors in order to obtain an alternative diagnosis in patients referred for rE.

METHODS

Between January 2010 and December 2015, 125 consecutive patients with a diagnosis of rE were prospectively enrolled. All patients underwent a comprehensive neurological, neuropsychiatric and cardiological evaluation, and had an observation time of at least 1 year after the study entry.

RESULTS

Diagnosis of rE was confirmed in 104/125 (83.2%) patients (55 women, mean age 38.8 ± 14.3 years). Thirteen/125 patients (10.4%, seven women, mean age 50.8 ± 20.9) were diagnosed with syncope, which was cardiac/cardio inhibitory in 9/13 (69%). The remaining 8/125 patients (6.4%, six women, mean age 41.2 ± 14.6 years) were diagnosed with psychogenic non-epileptic seizures. Age at onset had a high accuracy in differentiating patients with syncope from others, with the best cut-off age at 35 years and above. Abnormal brain magnetic resonance imaging (MRI) had a significant yield of about 70% in rE. A diagnostic model including age at onset and brain MRI was highly accurate in differentiating patients with syncope from others. In patients with cardiac/cardio inhibitory syncope, the point score of historical features was ≥1 and falsely favoured the diagnosis of epileptic seizures.

CONCLUSIONS

This prospective cohort study identifies rE mimics who are at high risk of morbidity and mortality. rE starting in adulthood should raise a high suspicion of cardiac syncope. Brain MRI is accurate in differentiating rE from other conditions.

The encephalogram as a risk predictive test for work at height

Background

Regulating standard 35 (NR-35) defines work at height as "any activity performed two meters above from ground level and involving risk of falls" and recommends the performance of medical examination to detect "conditions that might cause sudden loss of consciousness and falls from heights". As a result many occupational physicians began to recommend routine electroencephalogram (EEG) to assess employees working at height. However, the validity of EEG for asymptomatic workers is uncertain.

Objective

To analyze occupational accidents related to work at height occurring from January 1, 2000 to December 31, 2014, at a university hospital, and to correlate them with the results of EEGs performed along that period.

Methods

Cross-sectional study involving review of EEG test,s clinical-occupational records and Work Accident Reports (WAR) of all employees working at height from January 1, 2000 to December 31, 2014. Terms in the WAR descriptions were established to investigate the relationship of accidents with "sudden loss of consciousness and falls from heights", such as "fall from a height", "sudden ill feeling", "loss of consciousness", "vertigo", "dizziness" and "syncope". EEG results were classified in three categories: normal, non-epileptic abnormalities and epileptic patterns. WAR descriptions were correlated with EEG results.

Results

From 2,464 WARs issued along the investigated period, 2,228 were excluded because they did not correspond to work at height. From the remaining 236 WARs, 61 were excluded because EEG was not performed, therefore, 175 cases were included for analysis. Among the EEG tests assessed, 171 were normal, 4 exhibited non-epileptic abnormalities and none an epileptic pattern. Among all the analyzed cases, 13 descriptions included terms such as "fall from height", "loss of consciousness", "sudden ill feeling", "vertigo", "dizziness" and "syncope"; all the corresponding cases had normal EEG.

Conclusions

EEG was not a good predictor of risk for accidents related with work at height in the analyzed sample. EEG should not be performed for assessment of asymptomatic workers, but only in cases with clinical suspicion of neurological abnormalities.

Syncope and Epilepsy coexist in 'possible' and 'drug-resistant' epilepsy (Overlap between Epilepsy and Syncope Study - OESYS)

Background

Differential diagnosis between syncope and epilepsy in patients with transient loss of consciousness of uncertain etiology is still unclear. Thus, the aim of the present work is to evaluate the prevalence of syncope in patients with “possible” or “drug-resistant” epilepsy.

Methods

The Overlap between Epilepsy and SYncope Study (OESYS) is a multicenter prospective observational study designed to estimate the prevalence of syncope in patients followed in Epilepsy Centers for “possible” or “drug-resistant” epilepsy and assessed according the European Society of Cardiology (ESC) guidelines of syncope diagnosis.

Results

One hundred seven patients were evaluated; 63 (58.9%) had possible and 44 (41.1%) drug-resistant epilepsy. A final diagnosis of isolated syncope was in 45 patients (42.1%), all with possible epilepsy (45/63, 71.4%). Isolated epilepsy was found in 21 patients (19.6%) and it was more frequent in the drug-resistant than in the possible epilepsy group (34.1% vs. 9.5%, p = 0.002). More importantly, syncope and epilepsy coexisted in 37.4% of all patients but the coexistence was more frequent among patients with drug-resistant than possible epilepsy (65.9% vs. 17.5%, p < 0.001).

Conclusions

Isolated syncope was diagnosed in ≈ 70% of patients with possible epilepsy. Syncope and epilepsy coexisted in ≈ 20% of patients with possible and in ≈ 60% of patients with drug-resistant epilepsy. These findings highlight the need of ESC guidelines of syncope approach in patients with possible and drug-resistant epilepsy.

Neurological Complications of Cardiac Disease

This article focuses on the complex interactions between the cardiovascular and neurologic systems. Initially, we focus on neurological complications in children with congenital heart disease both secondary to the underlying cardiac disease and complications of interventions. We later discuss diagnosis and management of common syncope syndromes with emphasis on vasovagal syncope. We also review the diagnosis, classification, and management of children and adolescents with postural orthostatic tachycardia syndrome. Lastly, we discuss long QT syndrome and sudden unexpected death in epilepsy (SUDEP), reviewing advances in genetics and current knowledge of pathophysiology of these conditions. This article attempts to provide an overview of these disorders with focus on pathophysiology, advances in molecular genetics, and current medical interventions.

Data fusion for paroxysmal events' classification from EEG

BACKGROUND

Spatiotemporal analysis of electroencephalography is commonly used for classification of events since it allows capturing dependencies across channels. The significant increase of feature vector dimensionality however introduce noise and thus it does not allow the classification models to be trained using a limited number of samples usually available in clinical studies.

NEW METHOD

Thus, we investigate the classification of epileptic and non-epileptic events based on temporal and spectral analysis through the application of three different fusion schemes for the combination of information across channels. We compare the commonly used early-integration (EI) scheme - in which features are fused from all channels prior to classification - with two late-integration (LI) schemes performing per channel classification when: (i) the temporal context varies significantly across channels, thus local spatial training models are required, and (ii) the spatial variations are negligible in comparison to the inter-subject variation, thus only the temporal variation is modeled using a single global spatial training model. Furthermore, we perform dimensionality reduction either by feature selection or by principal component analysis.

RESULTS

The framework is applied on events that manifest across most channels, as generalized epileptic seizures, psychogenic non-epileptic seizures and vasovagal syncope. The three classification architectures were evaluated on EEG epochs from 11 subjects.

COMPARISON WITH EXISTING METHODS

Although direct comparison with other studies is difficult due to the different characteristics of each dataset, the achieved recognition accuracy of the LI fusion schemes outperforms the performance reported in the literature.

CONCLUSIONS

The best scheme was the LI with global model which achieved 97% accuracy.

An Emergency Medicine-Focused Review of Seizure Mimics

BACKGROUND

Seizures result in a change in motor, sensory, and behavioral symptoms caused by abnormal neurologic electrical activity. The symptoms share similar presentations of several other conditions, leading to difficulties in diagnosis and frequent improper management.

OBJECTIVE

This review evaluates adult patients with suspected seizure, signs and symptoms of seizure, mimics of seizure, and an approach to management of seizure mimics.

DISCUSSION

A seizure is caused by abnormal neurologic electrical activity resulting in altered motor, sensory, and behavioral symptoms. Other conditions may present similarly, causing a challenge in diagnosis. These conditions include syncope, psychogenic nonepileptic seizures, stroke or transient ischemic attack, sleep disorders, movement disorders, and migraines. Diagnosis of seizures in the emergency department (ED) is often clinical. Differentiation between seizures and other conditions can be difficult. Laboratories and imaging provide little benefit in definitive diagnosis in the emergency setting. For patients that have an apparent seizure, resuscitation and management is precedent while identifying any provoking factors and treatment of those factors. For adults recovering from suspected seizure, the combination of a focused history, physical examination, and additional studies can provide assistance in diagnosis.

CONCLUSIONS

Patients with an apparent seizure should be resuscitated with identification of provoking factors. Many conditions can mimic seizures. A focused history, physical examination, and additional studies will assist in differentiating seizures from mimics.

Evaluation of the first seizure patient: Key points in the history and physical examination

PURPOSE

This review will present the history and physical examination as the launching point of the first seizure evaluation, from the initial characterization of the event, to the exclusion of alternative diagnoses, and then to the determination of specific acute or remote causes. Clinical features that may distinguish seizures from alternative diagnoses are discussed in detail, followed by a discussion of acute and remote first seizure etiologies.

METHODS

This review article is based on a discretionary selection of English language articles retrieved by a literature search in the PubMed database, and the authors' clinical experience.

RESULTS

The first seizure is a dramatic event with often profound implications for patients and family members. The initial clinical evaluation focuses on an accurate description of the spell to confirm the diagnosis, along with careful scrutiny for previously unrecognized seizures that would change the diagnosis more definitively to one of epilepsy. The first seizure evaluation rests primarily on the clinical history, and to a lesser extent, the physical examination.

CONCLUSIONS

Even in the era of digital EEG recording and neuroimaging, the initial clinical evaluation remains essential for the diagnosis, treatment, and prognostication of the first seizure.

Adverse events following school-based vaccination of girls with quadrivalent human papillomavirus vaccine in Slovenia, 2009 to 2013

Adverse events following immunisation (AEFIs) with qHPV reported to the Slovenian AEFI Registry for the first four school years of the vaccination programme were analysed. We calculated annual reporting rates for 11-14 year-old vaccinees with AEFIs, using the number of qHPV doses distributed within the school-based vaccination programme as the denominator. Between September 2009 and August 2013, 211 AEFIs that occurred in 89 vaccinees were reported, a rate of 149.5 vaccinees with AEFI per 100,000 qHPV doses distributed. For five vaccinees, serious AEFIs (8.4 per 100,000 doses distributed) were reported. The highest reporting rates were for fatigue, headache, and fever (≥ 38.0⁰) (53.8, 40.3, and 35.3 per 100,000 qHPV doses distributed, respectively). As no AEFI resulted in permanent sequelae and they all were categorised as serious only due to the criterion of a minimum of one day of hospitalisation, this provides reassurance for the safety of our school-based HPV vaccination programme. Further AEFI surveillance is warranted to provide data for HPV vaccination programme monitoring and evaluation of its safety.

Syncope: Case Studies

Syncope, or the sudden loss of consciousness, is a common presenting symptom for evaluation by neurologists. It is not a unique diagnosis but rather a common manifestation of disorders with diverse mechanisms. Loss of consciousness is typically preceded by a prodrome of symptoms and sometimes there is a clear trigger. This article discusses several cases that illustrate the various causes of syncope. Reflex syncope is the most common type and includes neurally mediated, vasovagal, situational, carotid sinus hypersensitivity, and atypical forms. Acute and chronic autonomic neuropathies and neurodegenerative disorders can also present with syncope.

Type 1 Brugada pattern ECG due to supra-therapeutic phenytoin level

Brugada syndrome is an inherited arrhythmogenic disease, characterised by a coved-type ST segment elevation in right precordial leads and an increased risk of sudden cardiac death due to ventricular arrhythmia. To unmask or exacerbate a Brugada ECG pattern, class IA or IC antiarrhythmic agents are used, and clinicians can predict sudden cardiac death in a high-risk patient. However, phenytoin, one of the class IB agents, may induce a Brugada pattern ECG at a supra-therapeutic level and this association has rarely been reported. We describe a case of a patient with a phenytoin level about twice as high as the therapeutic level, which led to the emergence of a type 1 Brugada pattern ECG. Awareness should be made between this important association of supra-therapeutic phenytoin level and type 1 Brugada pattern ECG because symptomatic Brugada syndrome can lead to sudden cardiac death.

An Overview of Quadrivalent Human Papillomavirus Vaccine Safety: 2006 to 2015

BACKGROUND

A quadrivalent human papillomavirus (HPV4) type 6/11/16/18 vaccine (GARDASIL/SILGARD®) has been licensed in many countries around the world for the prevention of cervical, vulvar, vaginal, and anal cancers and precancers, as well as external genital warts causally related to HPV types 6/11/16/18. Across 7 phase 3 clinical trials involving more than 29,000 males and females ages 9-45 years, vaccination was generally well tolerated. Because of its expected public health benefit in reducing cervical cancer and other HPV-related diseases, the vaccine has been implemented in the national vaccination programs of several countries, with over 178 million doses distributed worldwide.

METHODS

Extensive efforts to assess the safety of the vaccine in routine practice have been conducted over the past 9 years since licensure, including more than 15 studies in more than 1 million preadolescents, adolescents and adults from various countries. Most have been performed in the general population although there have been some in special populations (pregnant women, HIV-infected individuals and those with systemic lupus erythematosus).

RESULTS

We present a summary of the published, postlicensure safety data from active and passive surveillance. Only syncope, and possibly skin infections were associated with vaccination in the postlicensure setting. Serious adverse events, such as adverse pregnancy outcomes, autoimmune diseases (including Guillain-Barre Syndrome and multiple sclerosis), anaphylaxis, venous thromboembolism and stroke, were extensively studied, and no increase in the incidence of these events was found compared with background rates.

CONCLUSIONS

These results, along with the safety data from the prelicensure clinical trials, confirm that the HPV4 vaccine has a favorable safety profile. Key policy, medical and regulatory organizations around the world have independently reviewed these data and continue to recommend routine HPV vaccination.

Plasma brain-type natriuretic Peptide level following seizure and syncope: pilot study

Background and Purpose:

To explore the clinical feasibility of plasma brain-type natriuretic peptide (proBNP) level to differentiate the two major causes of transient unconsciousness, seizure and vasovagal syncope (VVS) in adult patients.

Methods:

ProBNP levels were evaluated within 24 hours following attack in patients who had experienced a transient episode of unconsciousness. For confirmatory diagnosis, clinical history was reviewed thoroughly and several work-ups including electroencephalography and cerebral imaging and tilt-table test, were performed in cases of putative VVS, as a part of routine clinical approaches.

Results:

According to various relevant evaluations, 15 patients were diagnosed as seizure (age, 40.3±13.8 years) and 12 patients were VVS (age, 38.1±17.1 years). Plasma concentrations of pro-BNP were not different between two groups (p=0.714). Median level was 34.3 pg/mL (interquartile range: 12.9–91.1) in post-seizure group and 32.3 pg/mL (interquartile range 8.9–77.4) in post-VVS group. Additionally, it was not correlated with the sampling times within 24 hours after the episodes.

Conclusions:

The plasma level of pro-BNP has a limited clinical value in differentiating seizure and vasovagal syncope in adults. However, the more validated results with a large population should be sought in the future studies to confirm its value.

Transient loss of consciousness and syncope

Syncope describes a sudden and brief transient loss of consciousness (TLOC) with postural failure due to cerebral global hypoperfusion. The term TLOC is used when the cause is either unrelated to cerebral hypoperfusion or is unknown. The most common causes of syncopal TLOC include: (1) cardiogenic syncope (cardiac arrhythmias, structural cardiac diseases, others); (2) orthostatic hypotension (due to drugs, hypovolemia, primary or secondary autonomic failure, others); (3) neurally mediated syncope (cardioinhibitory, vasodepressor, and mixed forms). Rarely neurologic disorders (such as epilepsy, transient ischemic attacks, and the subclavian steal syndrome) can lead to cerebal hypoperfusion and syncope. Nonsyncopal TLOC may be due to neurologic (epilepsy, sleep attacks, and other states with fluctuating vigilance), medical (hypoglycemia, drugs), psychiatric, or post-traumatic disorders. Basic diagnostic workup of TLOC includes a thorough history and physical examination, and a 12-lead electrocardiogram (ECG). Blood testing, electroencephalogram (EEG), magnetic resonance imaging (MRI) of the brain, echocardiography, head-up tilt test, carotid sinus massage, Holter monitoring, and loop recorders should be obtained only in specific contexts. Management strategies involve pharmacologic and nonpharmacologic interventions, and cardiac pacing.

Right insular atrophy in neurocardiogenic syncope: a volumetric MRI study

BACKGROUND AND PURPOSE

Alterations in the central autonomic network are hypothesized to play a role in the pathophysiologic mechanism underlying neurocardiogenic syncope; however, few data are available regarding the structural changes of the brain in this condition. We used voxel-based morphometry and regional volumetry to identify possible neuroanatomic correlates.

MATERIALS AND METHODS

We prospectively studied 32 patients with neurocardiogenic syncope with a positive response to the head-up tilt test and 32 controls who had no history of syncope. We used voxel-based morphometry to compare GM volumes between patients and controls. In addition, regional volumes of structures known to be included in the central autonomic network were measured and compared between the groups. Correlation analyses were also performed between clinical variables and anatomic data.

RESULTS

Voxel-based morphometry showed a significant GM volume reduction in the right insular cortex in patients with neurocardiogenic syncope compared with controls (corrected P = .033). Regional volumetry showed a significant reduction of right insular volumes in patients compared with controls (P = .002, MANCOVA). Smaller right insular volumes in patients with neurocardiogenic syncope were related to larger drops in systolic (P = .020) and diastolic (P = .003) blood pressures during the head-up tilt test.

CONCLUSIONS

We observed a novel finding of right insular atrophy in patients with neurocardiogenic syncope with a positive response to the head-up tilt test, implicating the role of right insular dysfunction in the pathophysiologic mechanism underlying neurocardiogenic syncope. Our findings further support the hypothesis that right insular dysfunction may cause a decrease in sympathetic activity and a reciprocal increase in parasympathetic activity, leading to syncope.

Episodic syncope caused by ventricular flutter in a tiger (Panthera tigris)

A captive, 9-yr-old castrated male tiger (Panthera tigris) from an exotic cat sanctuary and rescue facility was observed to have three collapsing episodes within a 2-wk interval prior to being examined by veterinarians. No improvement in clinical signs was noted after empiric treatment with phenobarbital. During a more complete workup for epilepsy, ventricular flutter was observed on electrocardiogram (ECG). The arrhythmia resolved with a single intravenous bolus of lidocaine. Cardiac structure and function were unremarkable on echocardiogram and cardiac troponin I levels were within normal limits for domestic felids. No significant abnormalities were noted on abdominal ultrasound. Complete blood count and biochemistry panel were unremarkable, and heartworm antigen and Blastomyces urine antigen enzyme-linked immunosorbent assays were negative. Antiarrhythmic treatment with sotalol was initiated. On follow-up ECG performed 1 mo later, no significant arrhythmias were noted, and clinical signs have completely resolved.

Epilepsy misdiagnosed as long QT syndrome: it can go both ways

Cardiogenic seizures are common and could be the sentinel event heralding the presence of congenital long QT syndrome (LQTS). Distinguishing a cardiogenic seizure from a neurogenic one is of the utmost importance. Herein, we present the case of a 12-year-old boy with recurrent episodes of syncope and seizures. Despite absence of QT prolongation on electrocardiogram, absence of documented arrhythmias, a negative LQTS genetic test, and recurrent episodes while on nadolol beta-blocker therapy, he was diagnosed with LQTS and implanted with an implantable cardioverter defibrillator (ICD). When syncope and seizure occurred with normal sinus rhythm documented on the ICD, he was referred to neurology, and an electroencephalogram was positive for numerous bursts of bilaterally synchronous generalized discharges. He was started on antiepileptic treatment after which his seizures resolved. His LQTS diagnosis was removed, beta-blocker therapy discontinued, and his ICD was explanted. He has been seizure-free for over 2 years.