Nonconvulsive status epilepticus: value of a benzodiazepine trial for predicting outcomes

Managing nonconvulsive status epilepticus (NCSE) poses many challenges that would benefit from additional early measures to predict patient outcomes. Here, we evaluate clinical and electroencephalographic responses to an acute antiepileptic drug trial as an added measure for predicting outcomes in patients presenting with suspected NCSE.

We analyzed all patients referred to our Neurology Service with suspected NCSE assessed by a standard acute intravenous (IV) benzodiazepine (BDZ) protocol. We correlated patients' clinical and electrographic (EEG) responses to the BDZ trial with their subsequent outcomes, including survival, recovery of consciousness, and functional status at hospital discharge.

From 1990 to 2001, we identified 62 patients with NCSE who were initially evaluated with an acute IV BDZ protocol trial. A favorable clinical response with improvement in consciousness was observed in 22 patients (35%), whereas 40 (65%) were clinical nonresponders. All of the positive clinical responders (100%) survived, recovered consciousness, and exhibited good functional outcomes. In contrast, outcomes were significantly poorer (P<0.001) for the clinical nonresponders; only 14 (35%) recovered consciousness and 22 (55%) survived, with 59% of those survivors demonstrating poor functional outcomes. EEG improvement with BDZs also predicted better outcome, but it was less robust than the clinical response, with better subsequent recovery of consciousness (P<0.05), but not functional outcome or survival.

This study demonstrates that a clinical and, to a lesser degree, EEG response to an acute trial of IV BDZs are predictive of subsequent outcome in patients with suspected NCSE, and warrant further consideration and investigation for assessing and managing patients.