Long-term seizure outcome in patients with status epilepticus due to acute encephalitis

Abstract

Purpose: To investigate the long-term seizure outcome in patients with convulsive status epilepticus (CSE) due to acute encephalitis and identify early predictors for terminal seizure remission.

Methods: Based on a prospective registry of CSE, consecutive patients with CSE due to acute encephalitis were enrolled from July 2009 to November 2017, with follow-up ending in November 2018. Variables during hospital stay, seizure outcomes within 1 month after status epilepticus (SE), and seizure outcomes within 3 months after acute phase of encephalitis were assessed for predicting terminal seizure freedom.

Results: After a median 58-month observation period, 77 patients were included in this study. Twenty-eight (36%) patients died within 3 months, 22 (29%) patients had recurrent seizures after acute phase of encephalitis, and 27 (35%) patients attained terminal seizure freedom after acute phase of encephalitis. Patients with CSE due to autoimmune encephalitis had a higher rate of terminal seizure freedom than those with viral and other encephalitis. Among all living patients (n = 49), 26 (53%) patients were on anti-epileptic medication at the end of follow-up. STESS score on admission, seizure freedom throughout 1 month after SE, and seizure freedom throughout 3 months after acute phase were found to be independently associated with terminal seizure freedom.

Conclusions: Our study proposed a dynamic assessment system to identify patients for whom long-term use of anti-epileptic drugs (AEDs) might not be necessary. Our findings filled a gap in treatment decision on how long AEDs should be continued for patients with CSE due to acute encephalitis.

Keywords: Anti-epileptic drugs; Convulsive status epilepticus; Prediction; Recurrent seizures; Terminal seizure freedom.