Abstracts

Rationale: Differentiating psychogenic non-epileptic events (PNEE) from epileptic seizures can be challenging and there are often significant delays in the correct diagnosis. There are studies that identify some ictal semiological features such as pelvic thrusting and side-to-side head shaking to be of help in reaching the correct diagnosis. Limited data is available, however, regarding the postictal semiology of PNEE.Methods: We reviewed the 121 records of all patients age 18-89 admitted to the Epilepsy Monitoring Unit for video-EEG monitoring at Upstate Medical University from January to December 2014. Patients who were diagnosed with physiologic seizures (n=4), mixed epileptic and non-epileptic seizures (n=14) or those with no clear diagnosis (n=35) were excluded. All the videos of captured events of patients diagnosed with PNEE (n=38) and epileptic seizures (n=30) were reviewed. The events during which the patient was off the camera, did not have a clear clinical end, or was not adequately examined postictally were excluded.Results: Twenty patients with PNEE and 14 patients with epileptic seizures met the inclusion criteria, with a total of 48 and 26 events meeting the video inclusion criteria in each group, respectively. There was no significant difference between the mean age of the PNEE (41.7 years, SD=12.73) and epileptic group (41.36 years, SD=18.44) (p=0.71). Percentage of females in the PNEE group was 90% and in the epileptic group was 64.3%. No statistically significant difference was observed in the postictal time intervals between the end of the episode and any first verbal response, to the first correct verbal response, or to the first followed command between the two groups (Table 1). Presence of the following postictal semiology was analyzed in each group: a) rapidly shaking the head from side to side or rapidly blinking, as if regaining consciousness; b) scanning around the room with a confused look; c) immediately posing a question of “what happened?” or a similar question to the others in the room. Out of the 48 events in the PNEE group, 8 were associated with at least one of the postictal semiology a, b or c described above (16.7%), whereas none of the seizures in the epileptic group was associated with this postictal behavior (p<0.05). Considering the number of patients who presented this behavior (n=3), the difference between the two groups did not reach statistical significant level (p=0.25).Conclusions: In this study, we report some differences in the postictal semiology between PNEE and epileptic seizures. While postictal confusion can be common after epileptic seizures, none of the seizures in this group were associated with an abrupt postictal action or behavior portraying confusion or termination of it. On the other hand, more than 16% of the events in the PNEE group were associated with such a semiology. However, when considering the number of patients who expressed this behavior, this difference did not reach a statistically significant level. A larger sample size and further studies are needed to further investigate these differences.