Background and Purpose: Transient hyperammonemia can occur after episodes of seizure. To verify that transient hyperammonemia is a unique finding in seizure patients, we compared the change in blood ammonia concentration during the postictal period with that of other patients who suffered consciousness disturbances due to other disorders. Methods: We compared the results of a biochemical examination, including serum ammonia levels, between adult patients sent to the emergency department (ED) with seizure and those with other causes of consciousness disturbance. Results: Nineteen out of 31 patients with generalized epileptic seizures showed hyperammonemia at initial data measurement. Seventeen of these patients showed transient hyperammonemia. Only 10 patients with hepatic encephalopathy showed hyperammonemia, while none of the patients suffering from other causes of consciousness disturbance showed transient hyperammonemia within hours of arrival at the ED. Conclusion: Transient hyperammonemia was observed in the majority of generalized tonic-clonic seizure patients examined in this study but not in those with other causes of consciousness disturbance. Because ammonia is checked in patients presenting with transient consciousness disturbance to the ED, with or without witness, transient hyperammonemia could be an indicator of recent epileptic seizure.

Keywords:
Seizures, Epilepsy, Cognition, Hyperammonemia, Consciousness disturbance
1.
Chen DK, So YT, Fisher RS, Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology: Use of serum prolactin in diagnosing epileptic seizures: report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology 2005;65:668–675.
2.
Wyllie E, Lueders H, Pippenger C, VanLente F: Postictal serum creatine kinase in the diagnosis of seizure disorders. Arch Neurol 1985;42:123–126.
3.
Liu KT, Su CS: Postictal transient hyperammonemia. Am J Emerg Med 2008;26:388.e381–388.e382.
4.
Yanagawa Y, Nishi K, Sakamoto T: Hyperammonemia is associated with generalized convulsion. Intern Med 2008;47:21–23.
5.
Lowenstein J, Tornheim K: Ammonia production in muscle: the purine nucleotide cycle. Science 1971;171:397–400.
6.
Brouns F, Beckers E, Wagenmakers AJM, Saris WHM: Ammonia accumulation during highly intensive long-lasting cycling: individual observations. Int J Sports Med 1990;11(suppl 2):S78–S84.
7.
Katayama K: Ammonia metabolism and hepatic encephalopathy. Hepatol Res 2004;30(suppl 1):73–80.
© 2010 S. Karger AG, Basel
2010
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.