Placebo test in the diagnostics of pseudoepileptic seizures in children and adolescents

Objective: The psychogenic pseudoepileptic seizures can be provoked by suggestion and by placebo test. This is the possibility that differentiates them with epileptic seizures, if there is a chance to record with video EEG. In the developmental age the intravenous placebo tests are willingly used, moreover the oral placebo has probably the same effectiveness. The Aim of the study was to determined the effectiveness of oral placebo in provoking psychogenic paroxysm and bioelectrical brain disorders in children with pseudoepileptic seizures. We also evaluated the effectiveness of placebo in provoking epileptic seizures in children with coexisting epilepsy.

Methods: The placebo was given to 30 among 40 children with pseudoseizures which was diagnosed with video EEG. There were 36 girls and 4 boys aged 8 to 18 years (average 13 years) hospitalised in the Department of Neurology in Kraków between 2002-2004. The most frequent type of paroxysm were syncope which needed to be diagnosed, fainting, headache, dizziness, paroxysmal abdominal pain and visual disorders. In 15/40 children with paroxysmal nonepileptic events the epileptic seizures were coexisting. Methods: Pseudoepileptic seizures were provoked even by the video EEG monitoring, suggestion, hyperventilation and placebo probe. For deepening the assessment of the EEG pattern beside the hyperventilation reactions test of open and closed eye and photostimmulation were used. During the placebo probe video EEG was done with voice recording and analyses of the synchrony of clinic and EEG pattern.

Results: Among 30 children with pseudoepileptic seizures after placebo in 20 paroxysm during recording were observed. The character of the paroxysm was similar to the previous history. More frequently were observed behavioural and visual disorders and rare syncope. No epileptic seizures were developed by placebo. 19/30 children with clinically positive and negative placebo test, developed paroxysmal bioelectric activity.

Conclusions: The oral placebo test was clinically effective in diagnosis of the pseudoepileptic events in 2/3 children. It developed paroxysmal EEG pattern in children with clinically positive and also with negative placebo test.