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Triphasic Waves During Post-Ictal Stupor

Published online by Cambridge University Press:  18 September 2015

Abayomi Ogunyemi
Abayomi Ogunyemi*
Affiliation:
Division of Neurology, Health Sciences Centre and Faculty of Medicine, Memorial University. St. John’s
*
Division of Neurology, Health Sciences Centre, 300 Prince Philip Drive, St. John’s, Newfoundland, Canada A1B 3V6
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Abstract

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Background: The term, “triphasic wave” originally described an EEG pattern believed to be a marker for a specific stage of hepatic coma. For 4 decades, the diagnostic and prognostic specificity of the pattern remains controversial. Its pathophysiology also continues to be elusive. Methods: EEG recordings were obtained in three patients known or suspected to have primary generalized epilepsy. In 2 patients, the EEGs were part of long-term monitoring using simultaneous video-EEG telemetry. For the third patient, the EEG was secured only during the post-ictal unconsciousness. These 3 patients were specifically selected because of the presence of triphasic waves in their EEGs. Results: Triphasic waves were observed in the EEG of the 3 patients only during post-ictal unconsciousness. The pattern was transient, being preceded by generalized suppression and delta slow waves and followed by theta activities. Alpha rhythms supervened when the patients became fully alert. Conclusion: A post-ictal state should be considered in unconscious patients with triphasic EEG waves.

Résumé

Résumé

Ondes triphasiques pendant la stupeur postcritique. Introduction: On parlait initialement d’onde triphasique pour décrire un motif EEG qu’on croyait être un marqueur d’un stade spécifique du coma hépatique. Pendant 4 décennies, la spécificité diagnostique et pronostique de ce motif sont demeurées un sujet de controverse. Sa pathophysiologie demeure également obscure. Méthodes: Nous avons obtenu des enregistrements EEG chez trois patients avec un diagnostic certain ou soupçonné d’épilepsie généralisée primaire. Chez 2 patients, l’EEG faisait partie du suivi à long terme associé à la télémesure vidéo-EEG. Chez le troisième patient, l’EEG a été enregistré seulement pendant la période d’inconscience postcritique. Ces 3 patients avaient été choisis à cause de la présence d’ondes triphasiques à l’EEG. Résultats: Les ondes triphasiques ont été observées sur l’EEG des 3 patients seulement pendant la période d’inconscience postcritique. Le motif était transitoire, précédé d’une suppression généralisée et d’ondes delta lentes, et suivi d’activité thêta. Les rythmes alpha sont réapparus quand les patients ont été tout à fait réveillés. Conclusion: On doit considérer qu’il peut s’agir d’un état postcritique chez les patients qui sont inconscients et qui ont des ondes EEG triphasiques.

Type
Original Articles
Information
Canadian Journal of Neurological Sciences , Volume 23 , Issue 3 , August 1996 , pp. 208 - 212
Copyright
Copyright © Canadian Neurological Sciences Federation 1996

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