Abstracts

When seizures do not respond to medications, EEG-video monitoring is the gold standard to clarify the diagnosis, and in particular to make the diagnosis of psychogenic nonepileptic seizures (PNES). However, inpatient long-term EEG-video monitoring is costly and time consuming. When the diagnosis of PNES is strongly suspected on clinical grounds, we often perform short-term (1 or 2-hour) outpatient EEG-video monitoring with activation to record an episode and obtain a diagnosis. The purpose of this study was to analyze the yield of this technique. We reviewed data on all patients who underwent short-term outpatient (1 or 2-hour) EEG-video monitoring at our center (University of South Florida-Tampa General Hospital) over a 26-month period (October 2000 to January 2003). All patients were suspected of having PNES on clinical grounds. Activation was performed using verbal suggestion, hyperventilation, and photic stimulation, according to a published protocol [Benbadis et al, [italic]Neurology[/italic] 2000;55:1904-1905]. See figure. The total number of short-term outpatient EEG-video monitoring was 74, and an event was induced in 51 (69%). In 49 (66%) of 74, the habitual event was induced patients, allowing a definitive diagnosis. Of these 49, 47 had definite PNES, and 2 had a typical generalized tonic clonic seizure (induced by photic stimulation), consistent with an idiopathic generalized epilepsy. In 25 (34%) of 74 patients, no conclusion could be reached, either because no event was triggered (23 patients), or because the induced event was not the habitual type (2 patients).[figure1] In 66% of cases, a suspected diagnosis of PNES can be confirmed by [italic]short-term outpatient[/italic] (1or 2-hour) EEG-video monitoring with activation, thereby obviating the need for prolonged inpatient EEG-video monitoring.