[Hyperammonaemic encephalopathy due to valproic acid]. / Encefalopatía hiperamoniémica por ácido valproico.

INTRODUCTION: One of the less frequent idiosyncratic side effects of valproic acid (VPA) is encephalopathy. Here we report one case. CASE REPORT: An 83-year-old female with no relevant past history, who received treatment with VPA following a post-traumatic subarachnoid haemorrhage and two convulsive seizures. A few days later, she was admitted to the Emergency Department because of a progressive clinical picture of mental slowness, nauseas and apathy. The systemic examination was normal. Neurologically, the most striking features were inattention and disorientation, despite her having a good level of consciousness, and mental confusion. Levels of VPA were within the below-therapeutic range and the basic lab findings (including hepatic profile) were normal, except for hyperammonaemia. Neuroimaging studies and cerebrospinal fluid analysis were also normal. An electroencephalogram (EEG) showed signs of severe diffuse encephalopathy with slow, triphasic waves and a non-convulsive epileptic status was therefore ruled out. After withdrawing the VPA, the patient's condition improved until her basal situation was reached in 48 hours and the EEG became normal, as did her ammonium levels. CONCLUSION: When faced with a patient who has recently been taking VPA and who presents a clinical picture of mental confusion, the possibility of encephalopathy due to said drug must be taken into consideration.

Encefalopatía hiperamoniémica por ácido valproicomage / Hyperammonaemic encephalopathy due to valproic acid

Uno de los efectos adversos idiosincrásicos menos frecuentes del ácido valproico (VPA) es la encefalopatía.Presentamos un caso. Caso clínico. Mujer de 83 años sin antecedentes de interés, que tras sufrir una hemorragiasubaracnoidea postraumática y dos crisis epilépticas, recibe tratamiento con VPA. Pocos días después ingresa en Urgencias por cuadro progresivo de torpeza mental, náuseas y apatía. La exploración sistémica era normal. Neurológicamente destacaba la inatención y la desorientación a pesar de un buen nivel de conciencia y la confusión mental. Los niveles de VPA estabanen rango infraterapéutico y la analítica básica (incluido el perfil hepático) era normal, salvo por una hiperamoniemia. También eran normales los estudios de neuroimagen y el análisis del líquido cefalorraquídeo. Un electroencefalograma (EEG) reveló signos de encefalopatía difusa grave con ondas trifásicas y ondas lentas, por lo que se descartó un estado epiléptico noconvulsivo. Tras retirar el VPA, la paciente mejoró hasta su situación basal en 48 horas, y el EEG se normalizó, al igual que los niveles de amonio. Conclusión. Ante cualquier paciente al que se le haya instaurado VPA recientemente, y que presente uncuadro de confusión mental, es preciso considerar una encefalopatía por dicho fármaco

One of the less frequent idiosyncratic side effects of valproic acid (VPA) is encephalopathy. Here wereport one case. Case report. An 83-year-old female with no relevant past history, who received treatment with VPA following a post-traumatic subarachnoid haemorrhage and two convulsive seizures. A few days later, she was admitted to the Emergency Department because of a progressive clinical picture of mental slowness, nauseas and apathy. The systemic examination wasnormal. Neurologically, the most striking features were inattention and disorientation, despite her having a good level of consciousness, and mental confusion. Levels of VPA were within the below-therapeutic range and the basic lab findings (including hepatic profile) were normal, except for hyperammonaemia. Neuroimaging studies and cerebrospinal fluid analysiswere also normal. An electroencephalogram (EEG) showed signs of severe diffuse encephalopathy with slow, triphasic waves and a non-convulsive epileptic status was therefore ruled out. After withdrawing the VPA, the patient’s condition improved untilher basal situation was reached in 48 hours and the EEG became normal, as did her ammonium levels. Conclusion. When faced with a patient who has recently been taking VPA and who presents a clinical picture of mental confusion, the possibility of encephalopathy due to said drug must be taken into consideration