title: Valproic acid induced hyperammonaemic encephalopathy.
abstract: OBJECTIVE
  To observe clinical and laboratory features of valproic acid-induced hyperammonaemic encephalopathy in patients taking valproic acid.
  
  
  METHODS
  Observational study was conducted at the Neurology Department, Dow University of Health Sciences, Civil Hospital, Karachi, from February 26, 2010 to March 20, 2011. Ten patients on valproic acid therapy of any age group with idiopathic or secondary epilepsy, who presented with encephalopathic symptoms, were registered and followed up during the study. Serum ammonia level, serum valproic acid level, liver function test, cerebrospinal fluid examination, electroencephalogram and brain imaging of all the patients were done. Other causes of encephalopathy were excluded after clinical and appropriate laboratory investigations. Microsoft Excell 2007 was used for statistical analysis.
  
  
  RESULTS
  Hyperammonaemia was found in all patients with encephalopathic symptoms. Rise in serum ammonia was independent of dose and serum level of valproic acid. Liver function was also found to be normal in 80% (n = 8) of the patients. Valproic acid was withdrawn in all patients. Three (30%) patients improved only after the withdrawal of valproic acid. Six (60%) patients improved after L-Carnitine replacement, one (10%) after sodium benzoate. On followup, serum ammonia had reduced to normal in five (50%) patients and to more than half of the baseline level in two (20%) patients. Three (30%) patients were lost to followup after complete clinical improvement.
  
  
  CONCLUSIONS
  Within therapeutic dose and serum levels, valproic acid can cause symptomatic hyperammonaemia resulting in encephalopathy. All patients taking valproic acid presenting with encephalopathic symptoms must be monitored for the condition.
authors.affiliation: Department of Neurology, Dow University of Health Sciences and Civil Hospital, Karachi. dr.saimakashif@gmail.com
authors.forename: Saima
authors.initials: S
authors.lastname: Amanat
authors.forename: Naila
authors.initials: N
authors.lastname: Shahbaz
authors.forename: Yasmin
authors.initials: Y
authors.lastname: Hassan
mesh_terms: D000293:Adolescent; D000328:Adult; D000927:Anticonvulsants / Q000009:adverse effects*; D001927:Brain Diseases / Q000139:chemically induced* / Q000175:diagnosis* / Q000628:therapy; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004827:Epilepsy / Q000188:drug therapy; D005260:Female; D006801:Humans; D022124:Hyperammonemia / Q000139:chemically induced* / Q000175:diagnosis* / Q000628:therapy; D008297:Male; D010154:Pakistan; D014635:Valproic Acid / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D000927:Anticonvulsants; D014635:Valproic Acid