Pitfalls in EEG Analysis in Patients With Nonconvulsive Status Epilepticus: A Preliminary Study

Objective: Electroencephalography (EEG) interpretations through visual (by human raters) and automated (by computer technology) analysis were still not reliable for the diagnosis of nonconvulsive status epilepticus (NCSE). This study aimed to identify typical pitfalls in the EEG analysis and make suggestions as to how those pitfalls might be avoided. Methods: We analyzed the EEG recordings of individuals who had clinically confirmed or suspected NCSE. Epileptiform EEG activity during seizures (ictal discharges) was visually analyzed by 2 independent raters. We investigated whether unreliable EEG visual interpretations quantified by low interrater agreement can be predicted by the characteristics of ictal discharges and individuals’ clinical data. In addition, the EEG recordings were automatically analyzed by in-house algorithms. To further explore the causes of unreliable EEG interpretations, 2 epileptologists analyzed EEG patterns most likely misinterpreted as ictal discharges based on the differences between the EEG interpretations through the visual and automated analysis. Results: Short ictal discharges with a gradual onset (developing over 3 s in length) were liable to be misinterpreted. An extra 2 min of ictal discharges contributed to an increase in the kappa statistics of >0.1. Other problems were the misinterpretation of abnormal background activity (slow-wave activities, other abnormal brain activity, and the ictal-like movement artifacts), continuous interictal discharges, and continuous short ictal discharges. Conclusion: A longer duration criterion for NCSE-EEGs than 10 s that is commonly used in NCSE working criteria is recommended. Using knowledge of historical EEGs, individualized algorithms, and context-dependent alarm thresholds may also avoid the pitfalls.

Frequency and Types of Complications Encountered in Patients With Nonconvulsive Status Epilepticus in the Neurological ICU: Impact on Outcome

Objectives. The frequency and types of complications in patients with nonconvulsive status epilepticus (NCSE) who are followed up in the intensive care unit (ICU), and the impact of these complications on outcome are not well-known. We investigated the complications and their effects on prognosis in NCSE patients. Methods. After reviewing the video-EEG monitoring (VEEGM) reports of all the consecutive patients who were followed up in our ICU between 2009 and 2019, we identified two groups of patients: 1-patients with NCSE (study group) and 2-patients who underwent VEEGM for possible NCSE but did not have ictal recordings (no-NCSE group). Electronic health records were reviewed to identify demographic and clinical data, duration of ICU care, medical and surgical complications, pharmacologic treatment, and outcome. These parameters were compared statistically between the groups. We also investigated the parameters affecting prognosis at discharge. Results. Thirty-two patients with NCSE comprised the study group. Infection developed in 84%. More than half were intubated, had tracheostomy or percutaneous endoscopic gastrostomy application. Refractory NCSE was associated with significantly more frequent complications and worse outcome. There was a higher tendency of infections in the study group ( P = .059). Higher organ failure scores and prolonged stay in ICU predicted worse outcome ( P < .05). Conclusion. The frequency of complications in patients with NCSE who are cared for in the ICU is considerable. Most of the complications are similar to the other patients in ICU, except for the higher frequency of infections. Increased physician awareness about modifiable parameters and timely interventions might help improve prognosis.

Case Report: Hypopituitarism Presenting With Nonconvulsive Status Epilepticus

Introduction: Hypopituitarism is defined as one or more partial or complete pituitary hormone deficiencies. Nonconvulsive status epilepticus (NCSE) refers to a state of continuous or repetitive seizures without convulsions. In this paper, we review a case of an old female patient with hypopituitarism who presented with NCSE, which is rare in the clinic.Case Report: This paper describes a 67-year-old female patient with hypopituitarism who presented as NCSE. She had surgical resection of pituitary tumor half a year before the seizures and did not get regular hormone replacement therapy. She presented general convulsive status epilepsy as the initial symptom and got sedation and antiepileptic drug in the emergency room. The seizure was terminated but the patient fell in coma in the following days. The patient had magnetic resonance imaging (MRI) and other inspects, and EEG showed epileptic discharges. Combining these clinical symptoms and examinations, we made the diagnosis of NCSE. Finally, she regained consciousness after the treatment with diazepam.Conclusion: This case report and literature review investigated the possible mechanism of hypopituitarism presenting with NCSE.