Reevaluation of the Electroencephalogram Recordings of Patients with Nonconvulsive Status Epilepticus by using Salzburg Consensus Criteria

Abstract

Objective: Nonconvulsive status epilepticus (NCSE) is a challenge to diagnose in some cases, and recently, Salzburg consensus criteria for NCSE (SCC NCSE) were developed to contribute to clinical practice. We aimed to investigate their validity and usefulness by reevaluating the electroencephalogram (EEG) examinations of our patients in this study. Materials and Methods: We retrospectively evaluated all EEG recordings of patients diagnosed with NCSE by experienced clinical neurophysiologists in our EEG laboratory over a period of 2 years. Two neurologists trained in EEG reanalyzed all EEG data and categorized these patients as NCSE, possible NCSE, or non NCSE using the SCC NCSE. Results: Twenty nine patients with a mean age of 31.5 ± 25.9 were reanalyzed. According to the SCC NCSE, 24 patients (82.7%) were diagnosed as NCSE. Eighteen patients (62%) who fulfilled all SCC NCSE were diagnosed as NCSE, whereas six patients (20.7%) were diagnosed only as possible NCSE. Five patients (17.3%) did not fulfill SCC NCSE; the reasons are the lack of additional secondary criteria in 2 patients with encephalopathy, the absence of full compliance with the criteria in other 2 patients, and a diagnosis of electrical status epilepticus during sleep in the last patient. Conclusion: The results of our study show that SCC NCSE is highly consistent with clinical practice to decide for the diagnosis of NCSE. The evaluation of NCSE according to a set of new standardized criteria is thought to be difficult in practice, but it provides a more objective assessment. Therefore, we believe that its use should be encouraged to increase experience and the possibility of correct diagnosis.