Tc-99m HMPAO brain SPECT findings in pediatric viral encephalitis.

Two children were diagnosed with viral encephalitis, due to Epstein-Barr virus infection in one case and to herpes simplex virus infection in the other. Tc-99m HMPAO brain SPECT was arranged to detect changes in regional cerebral blood flow (rCBF) secondary to viral encephalitis. During the acute episode, Tc-99m HMPAO brain SPECT showed that the two cases had increased rCBF. After the acute episode, follow-up brain SPECT was arranged 6 months later. The rCBF in one case was restored to normal on the second brain SPECT, and that in the other case was decreased. The child with normal rCBF in the follow-up brain SPECT had better learning ability and intelligence than the other child with decreased rCBF.