The Clinical Features and Prognosis of Patients With Nonconvulsive Status Epilepticus in the Neurological Intensive Care Unit of a Tertiary Referral Center in Turkey

Abstract

The availability of video electroencephalography monitoring (VEEGM) in neurological intensive care units has allowed the recognition and treatment of nonconvulsive status epilepticus (NCSE). However, little is known about characteristics, management, and outcomes in patients with NCSE in developing countries. We retrospectively reviewed the video-EEG reports of 120 patients who were monitored from November 2009 to March 2013. Indications for video-EEG were mostly unexplained alterations of consciousness or witnessed convulsive seizures. We identified the clinical characteristics, treatment regimes, and outcomes of patients with NCSE and tried to determine which parameters were associated with prognosis. NCSE was detected in 12/120 (10%) patients (3 females, 9 males; age 24-86 years). Admission diagnoses were: stroke (3), epilepsy (3), autoimmune limbic encephalitis (3), herpes encephalitis (1), presumed encephalitis-cardiac arrest (1), and malignancy (1). Eight patients had witnessed convulsive seizures before video-EEG. Interictal periodic epileptiform discharges were detected in 9 patients. In one-third of patients, ≥2 EEG recordings were required to capture seizures. In addition to anticonvulsants, 3 patients received immunosuppressive therapy, while intravenous anesthetics were given to 7 patients. Four patients (33.3%; 1 female, 3 males; age 51-67 years; etiology: stroke, autoimmune encephalitis, encephalitis-cardiac arrest, and malignancy; Glasgow coma scale (GCS) score <8 in 3 patients; all had periodic discharges; intravenous anesthetics were used) died in the intensive care unit. NCSE is not an infrequent finding in neurological intensive care units, thus necessitating prolonged video-EEG monitoring in patients at risk. Witnessed convulsions may indicate the presence of nonconvulsive seizures in patients with altered consciousness. Repeated recordings may increase the detection of ictal events. Periodic epileptiform discharges are commonly observed and may predict poor prognosis. Mortality seems to be influenced mostly by the underlying etiology.

Keywords: neurological intensive care unit; nonconvulsive status epilepticus; outcome; video-EEG monitoring.