Abstracts

Rationale: Most patients with Psychogenic Nonepileptic Seizures (PNES) are medicated with antiepileptic drugs (AEDs). Refractoriness to this treatment is usually the main reason for referral to tertiary epilepsy centers and video-eeg monitoring. In this study we reviewed the response to AEDs in patients with PNES and its impact on the time of diagnosis.Methods: Retrospective review of medical records of 58 adult patients diagnosed with PNES without current or previous epilepsy, or history of febrile seizures. We evaluated the number of AEDS, colateral effects,, and efficacy in lowering the number of nonepileptic events.Results: Fifty-eight adult patients, with mean age of 35.9 years,(standard deviation: 10.7 years). Thirty-three (56.8%) were using AEDs (11 as monotherapy and 22 as polytherapy) and twenty-five were not on any anticonvulsivante treatment. The most commonly used AEDs was carbamazepine, followed by valproate and lamotrigine. Nineteen (57.5%) patients presented significant side effects: excessive sonnolency (33.3%), skin rash (18.1%), weight gain (18.1%), headaches (9.0%), irritability (9.0%) and cognitive complaints (9.0%). Three patients (9.0%) had intoxication caracterized by vertigo, ataxia and drowsiness. Twenty-two (66.6%) patients reported a positive response to AEDs. Three with full remission for at least one year, 17 with a decrease in the frequency of events and two with a change in the event semiology ( less intense seizures ). Time delay for the diagnosis in patients with positive response to AEDs was 10.1 years, and 5. 6 years in patients without any response to AEDs (p=0.035). Patients with PNES without AEDs (twenty-five patients, mean time for diagnosis: 4.1 years) and patients with PNES using AEDs without response had no difference in the time for correct diagnosis (p=0.51). Conclusions: Patients with PNEs may present a positive response to AEDs. This may be due to a placebo effect or to improvement of the psychiatric commorbidity (ie. depression). The positive response is a major fator to postpone the correct diagnosis of PNES.