Predicting nonepileptic seizures utilizing seizure frequency, EEG, and response to medication

The objective was to develop criteria that would prompt evaluation with video EEG monitoring in order to shorten the time to diagnosis of nonepileptic seizures. Over a period of 3 consecutive years, all patients being seen for seizures or the consideration of seizures meeting the following criteria were admitted for video EEG monitoring: (1) at least two events per week, (2) refractory to at least two medications, and (3) no prior EEG studies with epileptiform abnormalities after at least two attempts. A total of 13 patients met all three criteria, 11 of these patients had nonepileptic seizures, yielding a positive predictive value of 0.85. The median time from onset of symptoms until referral to the study institution was 3 years, with a range of 0-15 years. The median time from the first patient visit to a definitive diagnosis on video EEG monitoring was 1 month, with a range of 0-7 months. Patients meeting these three criteria frequently have nonepileptic seizures. These patients should undergo video EEG monitoring in a timely fashion to clarify the diagnosis.