Abstracts

Rationale: Accurately diagnosing seizures in the critically ill patient can be particularly challenging, given the high incidence of altered sensorium in this patient population. The purpose of this study was to analyze what conditions mimic seizures in the intensive care unit (ICU) setting. Methods: We retrospectively reviewed all bedside video-EEGs obtained in the adult ICU setting (age 18 or greater) from January 1, 2007 to April 30, 2008. All ICU patients whose reason for EEG was “possible seizures” had a video recording in addition to the EEG. Only those that had clinical events captured on video were analyzed. Results: A total of 41 video-EEGs were obtained. Eleven (27%) had epileptic seizures: 5 (45%) focal clonic, 2 (18%) myoclonic, 1 focal tonic, 1 focal status epilepticus, 1 generalized clonic, and 1 generalized tonic clonic. Thirty (73%) had non-epileptic events. Eleven (37%) had slow semi-purposeful movements, 9 of which involved one or more extremities, and 2 involved brief truncal flexion. Ten (33%) had tremor-like movements, involving the jaw, lip, one or more extremities, or were generalized. Four (13%) had myoclonic jerks. Three (10%) had transient eye movements. Two (7%) had repetitive mouth movements described as suckling or puckering. Two (7%) had head nodding or banging. Two (7%) had psychogenic nonepileptic attacks. One (3%) had abdominal fluttering which was attributed to artifact from artificial ventilation. Conclusions: Seizure mimics in the ICU are diverse, and different from the usual differential diagnosis of seizures seen in ambulatory patients. The majority are tremors and semi-purposeful movements likely related to discomfort.