[Paradoxical alpha waves seen in the course of subacute sclerosing panencephalitis]

Serial EEG findings of two cases with subacute sclerosing panencephalitis were compared with concurrent clinical status and CT findings. Case 1, a 16-year-old boy, showed transient abnormal diffuse alpha waves during sleep record. That had been seen for six months after the disappearance of periodic synchronous discharges. Clinically this abnormal EEG finding was observed at the transitional phase from stage II to III, when CT showed severe brain atrophy. Case 2, an 11-year-old boy, showed similar abnormal alpha waves for three months in the same phase as case 1. There have been many reports regarding the EEG findings of SSPE. However, these abnormal EEG findings were not reported. These abnormal alpha waves during sleep are considered to develop at the transitional phase from stage II to III, when pathologically SSPE goes from inflammation to destruction.