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Neurocardiogenic Syncope: Frequency and Consequences of its Misdiagnosis as Epilepsy

Published online by Cambridge University Press:  02 December 2014

Colin B. Josephson ,
Susan Rahey  and
R. Mark Sadler
Colin B. Josephson
Affiliation:
Neuroelectrodiagnostic Unit, Capital Health Authority
Susan Rahey
Affiliation:
Neuroelectrodiagnostic Unit, Capital Health Authority
R. Mark Sadler
Affiliation:
Department of Medicine, Dalhousie University, Halifax, NS, Canada
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Abstract

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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:

RÉSUMÉ: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 du début des syncopes était de 28 ± 16 ans. Les deux tiers des patients avaient été référés par le médecin de première ligne (salle d'urgence inclusivement) et 18 % par un neurologue. Des antiépileptiques avaient été prescrits à 35% des patients avant qu'ils ne soient référés à la clinique et 8 de ces patients (4,1%) ont eu une réaction d'hypersensibilité. Trois femmes sur cinq ont eu des conséquences défavorables sur leur grossesse alors qu'elles prenaient des médicaments antiépileptiques. Un tiers des patients ont vu leurs privilèges de conduite automobile restreints et 11 patients (5,7%) ont subi une interruption d'emploi. Les modalités diagnostiques suivantes ont été utilisées dans l'évaluation des patients : ÉEG (90%), tomodensitométrie de la tête (51%) et IRM de la tête (15%).

Conclusions :

La SNC est souvent diagnostiquée à tort comme étant de l'épilepsie. Chez certains patients, le diagnostic erroné avait été posé plus de 10 ans auparavant. Les patients qui ont reçu un tel diagnostic subissent souvent une évaluation excessive, sont traités de façon inappropriée et se voient imposer des restrictions inutiles quant à leur privilèges de conduite automobile et d'emploi.

Type
Original Articles
Information
Canadian Journal of Neurological Sciences , Volume 34 , Issue 2 , May 2007 , pp. 221 - 224
Copyright
Copyright © The Canadian Journal of Neurological 2007

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