Long-term outcome of psychogenic nonepileptic seizures : the role of induction by suggestion

PURPOSE: The aims of our retrospective observational study were to evaluate the long-term outcome of PNESs after communication of the diagnosis and to define predictors of good outcome. METHOD: Twenty-seven consecutive patients with a certain diagnosis of psychogenic nonepileptic seizures (PNESs) were included in the study. Follow-up information was obtained from each participant through a questionnaire designed for the study. Regarding seizure frequency, the patients were asked to report how many seizures they had experienced on average every month before the communication of the diagnosis and after it. RESULTS: After the communication of the diagnosis, the median seizure frequency had dropped to 4 every month (p < 0.001). Seventeen participants (63%) were seizure-free at follow-up, and a further five (18.5%) showed a greater than 50% improvement in seizure frequency. Regarding the predictive value of clinical and sociodemographic variables for PNES global outcome, the factors gender, education, economic status, interval of time from onset, comorbidity with epilepsy, psychiatric history, mental retardation, psychological therapy, psychiatric therapy, and the presence of stressful and traumatic events were not related to prognosis; the only factor associated with a better outcome was the diagnosis made after the induction of PNESs by suggestion (p = 0.000, χ(2) = 4.654). CONCLUSION: A substantial majority of our patients became seizure-free with communication of the diagnosis as the only intervention. The use of the induction by suggestion test was an important predictor of good outcome.