[Frequent convulsions in the post-eruptive stage of exanthem subitum].

We report here three infants with frequent convulsions in the post-eruptive stage of exanthem subitum (ES) due to human herpesvirus 6 (HHV-6) infection. Postictal electroencephalogram (EEG) showed in all the patients abnormal epileptic discharges, which disappeared in the following by three to eighteen months. In one case, brain magnetic resonance imaging (MRI) revealed focal gliosis. SPECT demonstrated hypoperfusion of the lesion. In the cerebro spinal fluid (CSF) of all the patients, HHV-6 DNA was negative on polymerase chain reaction (PCR) and HHV-6 antibodies were not significantly increased. Although encephalitis has been reported to complicate primary HHV-6 infection, our patients were not diagnosed as having encephalitis because of the clinical, CSF, EEG and CT findings. However, they had frequent convulsions. Not only virus invasion but also a secondary reaction including vasculitis may cause the central nervous system complications of HHV-6 infection. Frequent convulsions may occur in the post-eruptic stage after HHV-6 infection.