Diagnostic Yield of 8-Hour Video-EEG in Detecting Psychogenic Non-Epileptic Seizures (PNES)

To evaluate the diagnostic yield of the first 8 hours of video-EEG (vEEG) monitoring in detecting Psychogenic Non-Epileptic Seizures (PNES) during the Epilepsy Monitoring Unit (EMU) admission. We performed a retrospective chart review of patients ages ≥4 years who were admitted to the EMU between 2011 and 2018 (n = 616). We calculated the proportion of patients diagnosed with PNES within the first 8 hours of EEG recording and studied the associated risk factors for patients diagnosed with PNES and patients with epileptic seizures (ES). Out of the total 616 patients, 24% (149) patients had an EMU diagnosis of PNES. Of these, 44.3% had at least one typical event within the first 8 hours of vEEG monitoring. A higher incidence was seen within the pediatric subgroup (54.8% had an event within 8 hours). A diagnosis of chronic pain disorder was more common with PNES compared to ES (48.3% versus 16.5%, p < 0.001). A suspicion for PNES documented during an office visit was noted in a high proportion of patients (68.5%) who eventually had a PNES event during EMU. Our study suggests that in a well-selected group of patients (such as a high suspicion of PNES during a physician/neurology office visit), an outpatient 8-hour vEEG could open new avenues for a prompt diagnosis. This could especially be beneficial in hospital settings where there is either a lack of an EMU or a delay in admission to the EMU.