Refractory nonconvulsive status epilepticus in coma: analysis of the evolution of ictal patterns.

OBJECTIVE Nonconvulsive status epilepticus (NCSE) is currently considered as one of the most frequent types of status epilepticus (SE). The objective of the present study was to identify the natural history of the electrographical evolution of refractory NCSE and to establish the relationship between ictal patterns and prognosis. METHODS We analyzed, retrospectively, 14 patients with loss of consciousness and NCSE. The ictal patterns were classified as discrete seizures (DS), merging seizures (MS), continuous ictal discharges (CID), continuous ictal discharges with flat periods (CID-F), and periodic lateralized epileptiform discharges (PLEDs). RESULTS The ictal patterns were DS (n=7; 50.0%), PLEDs (n=3; 1.4%), CID (n=2; 14.3%), MS (n=1; 7.1%), and CID-F (n=1; 7.1%). CONCLUSIONS NCSE electrographic findings are heterogeneous and do not follow a stereotyped sequence. PLEDs were related to a higher probability of neurological morbidity and mortality.