Psychogenic non-epileptic seizures, prospective clinical experience: diagnosis, clinical features, risk factors, psychiatric comorbidity, treatment outcome

Abstract

In our study, we evaluated 249 patients with refractory seizures using video-EEG monitoring. In this sample, we identified 56 (22.5%) patients with psychogenic non-epileptic seizures - PNES only. Spontaneous seizures were recorded in 49 (87%) patients with PNES. Suggestive seizure induction using intravenous saline placebo was successful in 77.1% of induced PNES cases. Disease duration prior to PNES diagnosis was quite long. Prolonged past and current intake of high number of different antiepileptic drugs was also typical for these patients. We evaluated ictal PNES semiology. Whereas ictal EEG was normal in all PNES patients, interictal EEG was abnormal in 46.4%. Brain MRI was abnormal in 30.4%. Personality disorders were the most frequent psychiatric co-morbidity (in 44.6% of PNES patients), emotionally unstable (borderline) personality disorder was predominant (in 32.1% of PNES patients). Risk factors for epilepsy misdiagnosis and PNES manifestation are discussed. Therapeutic outcome after two years of combined treatment (psychopharmacotherapy and/or psychotherapy) is presented; approximately one third of patients were seizure-free following two years of treatment, one third of patients were responders (>or= 50% reduction in seizure frequency) and one third did not respond to treatment.