Abstracts

Rationale: Epileptic seizures (ES) and psychogenic non-epileptic spells (PNES) can co-exist, often posing diagnostic and therapeutic challenges. It is important to identify the group of patients who have both PNES and ES (PNES+ES), as their treatment will require a combination of AEDs and psychiatric therapy. We searched for characteristics that could help identify this subgroup among patients with PNES. Methods: We reviewed all consecutive patients admitted to the Vanderbilt University Medical Center Epilepsy Monitoring Unit (EMU) between July 1, 2007 and June 30, 2012, using our EMU database. We systematically evaluated the clinical characteristics of patients with both PNES+ES, in comparison to those with pure PNES to identify any factors that could predict the co-existence of PNES and epilepsy. Our study and data collection methods were approved by the institutional review board. A diagnosis of epilepsy (ES) was made if patient had recorded clinical seizures accompanied by ictal discharges, or clear epileptiform activity on EEG. A diagnosis of PNES was made if there was occurrence of a convulsive or unresponsive event without ictal or postictal EEG changes. The significance of clinical factors was calculated by Chi-square test. Results: We reviewed a total of 1567 patients. There were 466 (29.7%) patients with PNES only and 82 (5.2%) patients with ES + PNES. 70.1% of PNES only patients versus 75.6% of ES + PNES patients were female (p: 0.32). 58.1% of PNES only patients versus 41.4% of ES + PNES patients had accurate pre-EMU clinical suspicion (p: 0.005). 11% of PNES only patients versus 43.9% of ES + PNES patients required >1 EMU admission (p: 0.00001). 72.9% of PNES only patients versus 70.7% of ES + PNES patients had their first event within the first day of EMU admission (p: 0.89). When the first PNES event was within the first day 71.4% of PNES only patients versus 73.2% of ES + PNES patients had their event within the first 4 hours (p: 0.18). 89.1% of ES + PNES patients had their first PNES event after the ES events were recorded. Suggestibility was present in 51.5% of PNES only patients versus 36.5% of ES + PNES patients (p: 0.01). The mean duration of PNES only spells was 5.5 minutes however the mean duration of PNES spells in ES + PNES group was 6.4 minutes. Epilepsy risk factors were present in 48% of PNES only patients versus 76% of ES + PNES patients (p: 0.00001). 11.4% of PNES only patients versus 22% of ES + PNES patients had abnormal neurological examination (p: 0.008). 61.1% of PNES only patients had brain MRIs and 66.6% of these were normal; 64.6% of ES + PNES patients had brain MRIs and only 41.5% of these were normal (p: 0.0005). 33.9% of PNES only patients versus 45.1% of ES + PNES patients had family history of epilepsy (p: 0.05) Conclusions: Certain clinical and historical features could help differentiate the patients with co-existing PNES and ES from PNES only patients.