703
Possible pathophysiological mechanisms which may have been operative in this case include: a direct central nervous system (CNS) toxic effect of valproic acid; a paradoxical epileptogenic effect secondary to the drug; and an indirect CNS toxic effect mediated through valproic acid-induced hyperammonemia.
 a direct central nervous system (CNS) toxic effect: Effect; a paradoxical epileptogenic effect: Effect; hyperammonemia: Effect; valproic acid: Treatment; valproic acid: Treatment.Drug
Given event type and trigger, please tell me the arguments of all the listed option. Output format is "name1: role1; name2: role2". 
Event type: adverse event 
  Option: Treatment.Freq, Subject.Population, Combination.Drug, Subject.Gender, Treatment.Duration, Subject, Effect, Treatment, Treatment.Disorder, Subject.Disorder, Treatment.Route, Subject.Race, Treatment.Time_elapsed, Treatment.Dosage, Subject.Age, Treatment.Drug 
Text: {0} 
Answer:
 a direct central nervous system (CNS) toxic effect: Effect; a paradoxical epileptogenic effect: Effect; hyperammonemia: Effect; valproic acid: Treatment; valproic acid: Treatment.Drug