Ictal and interictal EEG findings and the diagnostic utility of iv diazepam in 78 patients with nonconvulsive status epilepticus (NCSE) are reported from the Department of Neurology, University of Virginia Health Sciences Center, Charlottesville, VA. Ictal discharges were generalized in 59 episodes (69%) of NCSE, diffuse with focal predominance in 15 (18%), and focal in 11 (13%). EEG characteristics were heterogeneous. Atypical spike and wave was the predominant pattern, and typical spike and wave of absence seizures was rare. Rhythmic delta with intermittent spikes was most prevalent in the group with diffuse and focal discharges. Response to iv diazepam, 1 or 2 mg every 30-60 sec, occurred at a dose < 8 mg. Focal NCSE was less likely to respond than generalized NCSE. Persistence of interictal focal discharges after diazepam may differentiate generalized from focal onset NCSE. 
COMMENT. NCSE is characterized by slowness in behavior and mentation, confusion, or stupor, lasting >1 hour and accompanied by EEG epileptiform, continuous activity, either generalized, focal, or focal with secondary generalization.
In a study of 253 adults with SE admitted to the Medical College of Virginia, Richmond, VA, mortality rates of patients with prolonged (>60 min) compared to nonprolonged (30-59 min) status were significantly different (32% cf 2.7%). Duration of status was a strong prognostic factor, while the type of seizure was not a determinant of mortality. The mortality rate was 30% in 70 patients with partial SE, and 20% in 180 with generalized SE. Anoxia and increasing age were significantly correlated with higher mortality.