Temporary pure red-cell aplasia during valproate monotherapy: Clinical observations and spectral electroencephalographic aspects

We report the case of a 4-year-old boy with pure red-cell aplasia associate d with sodium valproate monotherapy. Treatment with valproate was initiated because of idiopathic tonic-clonic seizures; he became free of seizures. D uring the introduction of and ongoing antiepileptic drug treatment, clinica l and laboratory controls using electroencephalographic (EEG) spectral anal ysis were performed at regular intervals and disclosed normal values. Ten m onths after the introduction of valproate, clinical examination was normal except for marked pallor. Peripheral blood showed macrocytic anemia and the bone marrow finding was isolated absolute erythroblastopenia. At the same time, significant changes in EEG background activity were present as well-d efined slowing. There was an increase in the relative power of theta activi ty and a decrease in alpha 2 activity in the occipital regions. Valproate w as discontinued and phenobarbital therapy introduced. A complete resolution of the hematologic damage was observed after valproate withdrawal. Recover y of the hematologic parameters started 14 days after discontinuation of va lproate therapy, while normalization of EEG background activity was observe d earlier. The patient maintained stable hematologic values and seizure con trol without disturbances of the spectral EEG. After 6 months of phenobarbi tal therapy, re-administration of sodium valproate was not followed by recu rrence of any clinical or electrophysiologic symptoms or abnormalities.