Epileptology of the first-seizure presentation: a clinical, electroencephalographic, and magnetic resonance imaging study of 300 consecutive patients

King, Mark A.; Newton, Mark R.; Jackson, Graeme D.; Fitt, Gregory J; Mitchell, L. Anne; Silvapulle, Mervyn J.; Berkovic, Samuel F.

doi:10.1016/s0140-6736(98)03543-0

Cited by 534 publications

(479 citation statements)

References 23 publications

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“…In total, 13% of all referrals to a Canadian tertiary adult epilepsy clinic were diagnosed with NCS. This number is consistent with those reported in population studies 14,15 or specialist clinics. 7 Some of our patients carried a diagnosis of epilepsy for over ten years.…”

Section: Discussionsupporting

confidence: 91%

Neurocardiogenic Syncope: Frequency and Consequences of its Misdiagnosis as Epilepsy

Josephson

Rahey

Sadler

2007

Can. j. neurol. sci.

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Neurocardiogenic (vasovagal/vasodepressor) syncope (NCS) is a reflex mediated loss of consciousness resulting from the failure of the autonomic nervous system to maintain adequate cerebral perfusion pressure. 1,2 Excessive peripheral venous pooling of blood in combination with aberrant responses of mechanoreceptors to compensatory cardiac hypercontractility results in a paradoxical reflex bradycardia and drop in peripheral vascular resistance. 3,4 The consequent cerebral hypoperfusion induces a transient loss of consciousness that is associated with abnormal movements (e.g. myoclonic jerks) in 12-90% of patients. 2,[5][6][7][8][9][10] Despite clinical guidelines that distinguish NCS ABSTRACT: Background: Neurocardiogenic syncope (NCS) can be mistaken as a seizure. We reviewed the frequency and diagnostic consequences of this misdiagnosis. Methods: A retrospective review of outpatient adult epilepsy clinic charts (QEII Health Sciences Centre, Halifax, NS) was conducted to identify NCS patients referred with a provisional diagnosis of seizures. Charts were reviewed in detail with an emphasis on the consequences of misdiagnosis. Results: Of 1506 consecutive referrals to the epilepsy clinic, 194 (12.9%) ultimately had a clinical diagnosis of NCS. Mean age was 38 +/-16 years (mean age of syncopal onset was 28 +/-16 years). Two-thirds of referrals were from primary care physicians (including emergency departments) and 18% from neurologists. Thirty-five percent were prescribed antiepileptic drugs (AEDs) prior to referral with eight patients (4.1%) experiencing hypersensitivity reactions. Three of five women had adverse pregnancy outcomes while taking AEDs. One-third of patients had restrictions placed on their driving privileges while 11 patients (5.7%) had their employment interrupted. Diagnostic modalities used in the work-up included EEG (90%), CT head (51%), and MRI head (15%). Conclusions: NCS is commonly misdiagnosed as epilepsy. Some patients had an incorrect diagnosis for > 10 years. Patients with this misdiagnosis are often excessively investigated, inappropriately treated, and have unnecessary restrictions placed on driving and employment. RÉSUMÉ: Syncope neurocardiogénique : fréquence et conséquences d'un diagnostic erroné d'épilepsie.Contexte : Une syncope neurocardiogénique (SNC) peut être prise à tort pour une crise convulsive. Nous revoyons la fréquence et les conséquences d'un tel diagnostic erroné. Méthodes : Nous avons effectué une révision rétrospective des dossiers de patients de la clinique externe d'épilepsie (QEII Health Sciences Centre, Halifax, NS) afin d'identifier les patients ayant présenté une SNC qui y ont été référés avec un diagnostic provisoire de crise convulsive. Les dossiers ont été révisés en détail, particulièrement en ce qui concerne les conséquences d'un diagnostic erroné. Résultats : On a posé ultérieurement un diagnostic de SNC chez 194 (12,9%) de 1506 patients consécutifs référés à la clinique d'épilepsie. L'âge moyen des patients était de 38 ± 16 ans et l'âge moyen au moment ...

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Section: Discussionsupporting

confidence: 91%

Neurocardiogenic Syncope: Frequency and Consequences of its Misdiagnosis as Epilepsy

Josephson

Rahey

Sadler

2007

Can. j. neurol. sci.

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“…The time to obtain an EEG for hospitalized or ER patients was also shorter (one day or less, compared to a median of 14 days for the study population as a whole). The yield of an EEG in epilepsy is higher when it is performed within 24 hours of the event 10 , although as stated the higher yield for internists and ER physicians in our study related exclusively to slowing and not epileptic abnormalities.…”

Section: Discussioncontrasting

confidence: 46%

“…A third limitation is the median time of two weeks to obtain an EEG. An EEG is more likely to be abnormal in patients with seizures if it is done within 24 hours of the event 10 . We cannot exclude the possibility that we would have found a greater number of abnormal EEG's if the median time was shorter.…”

Section: Discussionmentioning

confidence: 99%

EEG in Suspected Syncope: Do EEGs Ordered by Neurologists Give a Higher Yield?

Poliquin‐Lasnier

Moore

2009

Can. j. neurol. sci.

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Syncope is often difficult to distinguish from a seizure because both can present clinically with a transient loss of consciousness 1 . Published studies have found that the electroencephalogram (EEG) is of low diagnostic yield when the clinical diagnosis is syncope [2][3][4][5] . Reviews state that EEGs should not be performed routinely in cases of suspected syncope unless there has been a witnessed seizure 6 , there is a history of prior seizures 7,8 , or there are "symptoms suggestive of a seizure" 7,9 . Electroencephalograms ordered by a neurologist might be expected to have a higher diagnostic yield because most neurologists are experienced in evaluating patients with syncope and seizures, and presumably would only refer a patient with suspected syncope for an EEG if there was something ABSTRACT: Background: Prior studies have shown that the electroencephalogram (EEG) is of low diagnostic yield in the evaluation of syncope but have not looked at the yield according to referring physician specialty. The goals of this study were to determine if the yield of the EEG is higher when ordered by neurologists and whether EEGs with abnormal findings resulted in any significant change in patient management. Methods: We retrospectively reviewed the records of the EEGs requested for a clinical diagnosis of syncope, convulsive syncope, loss of consciousness, or falls from 2003 to 2007 at our institution. We obtained further information from the medical record of patients with an abnormal EEG. Results: Of 517 EEGs meeting our inclusion criteria, only 57 (11.0%) were read as abnormal. No EEG was positive for epileptiform activity and only 9 (1.6%) showed potentially epileptic activity. EEGs ordered by neurologists did not have a higher yield compared to non-neurologists. Five abnormal EEGs resulted in further investigations being ordered. One patient was ultimately started on phenytoin. Conclusions: EEGs requested for the evaluation of patients with suspected syncope have an extremely low diagnostic yield and do not significantly alter the management of the patients, regardless of the specialty of the referring physician. RÉSUMÉ: L'EEG chez les patients suspects de syncope : les EEG demandés par les neurologues donnent-ils un meilleur rendement? :Contexte : Des études antérieures ont montré que l'électroencéphalogramme (EEG) offre un rendement diagnostique faible dans l'évaluation de la syncope, mais ces études n'ont pas examiné le rendement selon la spécialité du médecin qui réfère le patient. Les buts de cette étude étaient de déterminer si le rendement de l'EEG est plus élevé quand il est demandé par un neurologue et si les EEG dont les résultats sont anormaux entraînaient des changements significatifs dans le traitement du patient. Méthodes :Nous avons revu de façon rétrospective les dossiers des EEG demandés de 2003 à 2007 dans notre institution à cause d'un diagnostic clinique de syncope, de syncope convulsive, de perte de conscience ou de chute. Nous avons tiré des informations complémentaires des dossiers médicaux...

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“…In general, an EEG should be performed within 24 hours of the seizure to maximize diagnostic yield. 103 Doppler studies performed in 185 patients were abnormal in 19 patients but had no diagnostic yield. 104,105 However, neurology consultations were obtained in only 18% patients undergoing such studies, suggesting that most tests were requested by non-neurologists.…”

Section: Neurological Evaluation For Syncopementioning

confidence: 99%

Evaluation and Management of Syncope

Bindra

Marchlinski

Lin

2008

Clinical medicine. Circulatory, respiratory and pulmonary medic

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Context Syncope is a commonly encountered by primary care physicians and cardiologists. Etiology is frequently not apparent, and patients may undergo unnecessary tests. Treatment must be tailored to the likely etiology. Complexities of diagnosis and treatment often warrant referral to a specialist. Objective To highlight the evolving recommendations for managing syncope in a clinically and cost effective manner. Evidence Acquisition An electronic literature search was undertaken of the Medline database from January 1996 to April 2006, using the Medical Subject Heading syncope, defibrillators, pacemakers, echocardiogram, cardiomyopathy, long QT syndrome, Arrhythmogenic right ventricular dysplasia, and Brugada syndrome. Abstracts and titles were reviewed to identify English-language trials. Bibliographies from the references as well as scientific statements from the Heart Rhythm Society, American Heart Association, and American College of Cardiology were reviewed. Evidence Synthesis A methodical approach to syncope can improve diagnosis, limit testing, and identify patients at risk of fatal outcome. A thorough history, physical exam and electrocardiogram are critical to the initial diagnosis. Presence of heart disease determines the extent of work-up and treatment. A trans-thoracic echocardiogram should be performed in patients with an unclear diagnosis and a positive cardiac history or an abnormal ECG. Ventricular arrhythmias are the most common cause of syncope in patients with structural heart disease. Patients with an ejection fraction less than 30 percent should receive an implantable defibrillator with few exceptions. An electrophysiology study may assist risk stratification in syncopal patients with borderline ventricular function. In patients without structural heart disease, the presence of a well defined arrhythmia syndrome consistent with a genetically determined risk of sudden death must be sought. The 12-lead electrocardiogram, family history and clinical presentation will identify most high-risk patients. Patients without structural heart disease can often be managed conservatively with well defined strategies for preventing neurocardiogenic syncope. Conclusions Managing syncope requires a methodical approach. An understanding of the limitations of the diagnostic tools and treatments is important. Lethal causes of syncope make it imperative to recognize the appropriate timing of referring patients to specialists.

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Epileptology of the first-seizure presentation: a clinical, electroencephalographic, and magnetic resonance imaging study of 300 consecutive patients

Cited by 534 publications

References 23 publications

Neurocardiogenic Syncope: Frequency and Consequences of its Misdiagnosis as Epilepsy

Neurocardiogenic Syncope: Frequency and Consequences of its Misdiagnosis as Epilepsy

EEG in Suspected Syncope: Do EEGs Ordered by Neurologists Give a Higher Yield?

Evaluation and Management of Syncope

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