Non-Convulsive Status Epilepticus Features with Electroencephalography Monitoring in the Neurological Intensive Care Unit: A Prospective Study

Abstract

Objectives:Since non-convulsive status epilepticus (NCSE) is a reversible cause of coma and/or change in consciousness in the neurological intensive care unit (NICU), its early diagnosis and treatment are necessary. Continuous electroencephalography monitoring (cEEG) is an important diagnostic tool, but since access to cEEG may be limited, it is critical to choose which patients will be referred to cEEG for diagnosing NCSE. In our study, we aimed to investigate patients with an unexplained altered level of consciousness who should be directed to cEEG according to clinical features and emergency EEG (EmEEG) features.Methods:In 40 consecutive patients who were admitted to the NICU and whose reason for the altered mental status could not be explained, 30 min EmEEG and cEEG starting in the first 24 h were performed and their clinical features, Glasgow Coma Score (GCS), four score (FS), and prognosis were noted.Results:The frequency of NCSE was 22.5%. cEEG did not detected NCSE in patients who were not diagnosed in the EmEEG. No causality relationship was found between NCSE etiology, low GCS score, low FS, and the level of consciousness. The 55% of the NCSE patients had minor motor movements. The poor prognosis was 55% in the NCSE patients, but it did not differ significantly from the non-NCSE patients. In conclusion, EmEEG is a useful tool for NCSE screening in NICU patients at the early phase of changes in consciousness. Apart from minor motor movements, clinical and history characteristics do not predict the high NCSE risk. The unfavorable prognosis is probably related to the underlying etiology and is not affected by the presence of NCSE.Conclusion:When there is no access to cEEG, EmEEG may be helpful for the diagnosis of NCSE in the early clinical period. The presence of minor motor movements and EmEEG findings together can be useful tools to guide high-risk patients with NCSE to cEEG monitoring.

Keywords

• electrographic seizure
• neurological intensive care
• non-convulsive seizure
• status epilepticus