The clinical and EEG characteristics of initial status epilepticus (SE) during infancy were studied in six patients seen in the emergency clinic between 1977 and 1988 at Tokyo Women’s Medical University, Japan. Patients selected for review of medical records and laboratory findings at the time of treatment for the SE were those who subsequently developed mesial temporal epilepsy (MTLE). SE had occurred at a mean age of 14 months (range 7 months to 2 years 9 months). Two patients had developed SE during exanthem subitum. SE was characterized by fever, unilateral or generalized, prolonged seizures, SE lasting 120-380 minutes (mean 227 min), postictal prolonged unconsciousness, and Todd’s paresis in 3 of 6. EEG findings were lateralized to the side of the hippocampal atrophy later confirmed by MRI, despite generalized SE. Hippocampal atrophy was thought to have preceded the SE in 2 patients. Follow-up EEGs at 6 months and after development of complex partial seizures (CPS) showed temporal spike discharges. The latency between onset of SE and CPS ranged from 3 months to 13 years 3 months. EEG temporal lobe spikes did not appear until after the onset of recurrent CPS. 
COMMENT. Temporal lobe epilepsy may be expected in 7.5% of infants following febrile SE, with a follow-up period of 5 to 21 years (Awaya Y et al. 1992). Infants who develop hippocampal sclerosis and subsequent temporal lobe epilepsy following infantile SE have suffered a complicated and prolonged generalized or lateralized SE with fever, protracted postictal unconsciousness, lateralized EEG abnormalities, and a high incidence of Todd’s paresis. The appearance of temporal lobe spikes in the EEG is delayed until after the onset of complex partial seizures.