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Valproate-Induced Hyperammonemic Encephalopathy Followed by Benzodiazepine Withdrawal in a Patient With Schizoaffective Disorder: A Differential Diagnosis
J. Sarlon; E. Hess; A. Krasnianski
The Journal of Neuropsychiatry and Clinical Neurosciences 2013;25:E69-E70. doi:10.1176/appi.neuropsych.12090218
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Dept. of Psychiatry, Psychosomatics, and Psychotherapy J.W. Goethe University Frankfurt, Germany

Correspondence: jan.sarlon@kgu.de

Copyright © 2013 American Psychiatric Association


To the Editor: Valproate-induced hyperammonemic encephalopathy (VNHE) is a rare, but severe, drug-related adverse effect characterized by lethargy, vomiting, cognitive slowing, and focal neurological deficits.1,2 Valproate encephalopathy can be observed under normal plasma levels as well as under increased plasma levels of valproate.3 It occurs in monotherapy as well as in combination with other drugs.4 If the patient receives benzodiazepines simultaneously, the differential diagnosis may be more difficult.5

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FIGURE 1. EEG Recordings Before [a], During [b], and After [c] Valproate Treatment


Stewart  JT:  A case of hyperammonemic encephalopathy after 11 years of valproate therapy.  J Clin Psychopharmacol 2008; 28:361–362
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Fassi  G;  Igoa  A;  Liste  OA:  [Valproate-induced hyperammonemic encephalopathy: review of cases in the psychiatric setting].  Vertex 2008; 19:371–377
Durán-Ferreras  E;  Jiménez-Vilches  PL;  Galá-Barranco  JM  et al:  [Hyperammonaemic encephalopathy due to valproic acid].  Rev Neurol 2008; 46:537–539
Mehndiratta  MM;  Mehndiratta  P;  Phul  P  et al:  Valproate-induced non-hepatic hyperammonaemic encephalopathy (VNHE): a study from tertiary care referral university hospital, north India.  J Pak Med Assoc 2008; 58:627–631
Trojak  B;  de la Gastine  B;  Dollfus  S:  Valproate-induced encephalopathy related to concurrent antimanic medications.  J Neuropsychiatry Clin Neurosci 2011; 23:E22–E23
[CrossRef] | [PubMed]
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