Sensitivity and specificity of induction of psychogenic non-epileptic seizures in children and adolescents

Purpose: The purpose of this study was to investigate the sensitivity and specificity of a standardized placebo protocol using a moist swab pad application in children and adolescents with psychogenic seizures vs epileptic seizures.

Methods: We retrospectively reviewed clinical data and video-EEG monitoring records with the standardized placebo protocol of 408 patients. Video -EEG diagnosis with PNES-consistent semiology was made in the context of clinical data by a two-certified epileptologist. Results of induction of psychogenic seizure by moist swab pad application were analyzed in 158 patients with PNES. A control group was composed of 74 patients with epilepsy in which induction was performed.

Results: Sensitivity of placebo test for the diagnosis of PNES was 81.1%, specificity 79.8%, positive predictive value 89.6% and negative predictive value 66.3%.

Conclusion: The placebo technique with a moist swab can be regarded as helpful in triggering a psychogenic episode in children and adolescents.