Absence status: with special reference to the psychiatric symptoms directly related to the occurrence of seizure activity.

Six cases of absence status (age 4-40) have been reported from our center. The clinical and electroencephalographic features of 49 reported Japanese patients (including the cases from our center) have been analyzed and classified into subgroups. As a result, it was possible to classify absence status into three subgroups: typical absence status, atypical absence status and ictal stupor. In each subgroup, there were significant features in the onset age, history of epilepsy, electroencephalographic features and prognoses, and the cases of ictal stupor were least related to epilepsy. Consequently, it was mentioned that a part of psychiatric symptoms of absence status could be evaluated as transient ictal psychosis.