The Clinical Spectrum of New-Onset Status Epilepticus

Objectives: There is a paucity of data on patients with new-onset status epilepticus in patients without a prior history of epilepsy; we aimed to describe clinical characteristics and assess variables predictive of outcomes. Design: Retrospective cohort. Setting: Quaternary academic medical center. Patients: Adult patients with new-onset status epilepticus. Methods: Retrospective review of adults with new-onset status epilepticus admitted to Mayo Clinic, Rochester MN between January 1, 1990, and December 31, 2015, was performed. Patient demographics, status epilepticus etiology, Status Epilepticus Severity Score, and status epilepticus classification per the Status Epilepticus Severity Score were recorded. Six-month mortality and functional outcomes defined as modified Rankin scale (>= 3 at last follow-up was considered poor) were primary outcomes. Refractory status epilepticus was a secondary outcome. Interventions: None. Measurements and Main Results: One-hundred seventy-seven patients were included. Status epilepticus was convulsive in 124 (70.1%) and nonconvulsive in 53 (29.9%); 96 cases (54.2%) were refractory status epilepticus. Mean age at onset was 63 +/- 18 years; 52.5% were greater than or equal to 65 years. Etiologies were acute in 50.8%, progressive in 18.1%, remote in 19.2%, and unknown in 11.9% patients. Six-month mortality was 32.2%, and 70.1% had poor modified Rankin scale at mean follow-up 3.1 +/- 3.5 years. Age greater than or equal to 65 was a significant predictor of poor functional outcome and 6-month mortality. Loss of consciousness, status epilepticus classification, or age greater than or equal to 65 did not predict progression to refractory status epilepticus. Progression to refractory status epilepticus did not impact functional outcome or mortality at last follow-up. Conclusions: Poor outcomes in new-onset status epilepticus were associated with older age as well as predominantly progressive or remote symptomatic disease. Further prospective investigations assessing the course and outcomes of these patients would be useful in management and prognostication.