What’s shaking in the ICU? The differential diagnosis of seizures in the intensive care setting

To analyze what conditions mimic seizures in the intensive care unit (ICU) setting, we reviewed all bedside electroencephalography (EEG)-videos obtained in the adult ICU setting over an 18-month period. Only those studies performed for "possible seizures" due to motor phenomena and whose clinical events were captured on video were analyzed. A total of 52 studies were performed. Fourteen patients (27%) had epileptic seizures. Thirty-eight (73%) had nonepileptic events. These consisted of 12 (23%) with tremor-like movements, 7 (13.5%) with multifocal myoclonic jerks without electrographic changes, 7 (13.5%) with slow semipurposeful movements, and 10 with other movements. Therefore, seizure mimics in the ICU setting were diverse and distinct from the usual differential diagnosis of seizures seen in ambulatory patients.