This patient should have continuous monitoring with electroencephalography (EEG) because his presentation is concerning for nonconvulsive status epilepticus (NCSE). Approximately 48% of patients treated for convulsive status epilepticus (CSE) will continue to have subtle or subclinical seizures on EEG. Persistently altered mental status, particularly with waxing and waning features and focal neurologic deficits (such as aphasia), is a characteristic feature of NCSE. Patients with intracranial structural abnormalities who are comatose also are at high risk for this disorder. Intracerebral hemorrhage is an additional risk factor for nonconvulsive seizures and status epilepticus.

Continuous EEG monitoring is twice as sensitive as a routine 30-minute EEG for detecting seizures, especially the intermittent seizures that are common in patients already treated for CSE. All patients with altered mental status after CSE should have continuous EEG monitoring for at least 24 hours to detect nonconvulsive seizures or a changed status. Comatose patients should be evaluated for 24 to 48 hours. Continuous EEG monitoring is indicated in patients with acute structural intracranial lesions and altered mental status, even if clinically evident seizures have not occurred.

Flumazenil should not be administered to any patient with seizures or at risk for seizures because the drug can precipitate status epilepticus. Because the patient is not showing any signs of respiratory depression or other adverse effects of medication, there is no urgent need to reverse the benzodiazepine he received as part of appropriate CSE treatment.

Cavernous malformations usually have self-limited bleeding, and this patient does not have any mass effect or other urgent need for surgery. Although he ultimately may be a surgical candidate, given that refractory seizures are associated with cavernous malformations, surgical resection is not the most appropriate next step. He first should be evaluated and treated for NCSE.

Maintenance antiepileptic drugs (AEDs) should not be withheld in a patient with CSE at presentation unless the drugs are clearly causing severe adverse effects. In this patient, NCSE is a more likely explanation of the patient's mental state than is an adverse effect of the AED.