Moving Beyond Ruling Out Epilepsy: It Is PNES!

Commentary Patients with psychogenic nonepileptic seizures (PNES) have historically lived in the borderland between neurologists and psychiatrists, with neither group taking ownership of patient care. Past approaches to the diagnosis of PNES have largely focused on " removing the diagnosis of epilepsy " and sending the patient for psychiatric but not necessarily neurologic follow-up. Making the diagnosis is a critical first step for proper clinical management. It prevents further iatrogenic complications (i.e., removing unnecessary anti-epileptic drugs [AEDs]) and creates an opportunity for patients to receive the psychiatric care they need. Typically, patients with PNES come to diagnosis after 7 to 10 years of treatment for " epilepsy. " There is a high cost associated with this diagnostic delay (1). Proper diagnosis is also critical for research trials, which can move treatments forward and allow for the comparability of various study findings. The incidence of PNES has been estimated at 3 to 5 per 100,000 patients per year or about 20 to 30% of referrals to epilepsy centers (2). The prevalence and burden are probably much higher though, owing to a lack of identification of patients with infrequent events, presentation to nonspecialists, evaluation refusals, and inability to capture events during video-EEG monitoring. While there are multiple studies describing semiologic differences and the sensitivity and specificity of certain signs that help to distinguish PNES from epileptic seizures, epilepsy monitoring units (EMUs) vary with regard to the percentage of patients admitted for spell clarification that eventually are diagnosed with " not having epilepsy. " In any EMU, rendering this diagnosis is something that must be handled adeptly. For the approximately 16% of cases discharged from the EMU without a clear diagnosis, guidelines on how to proceed for further diagnostic clarification and management are lacking (3). Those within this undefined group who have PNES will likely be even more difficult to control when they are eventually clarified as psychogenic. The past 10 years have seen a marked increase in research in PNES and other functional neurologic symptom disorders (aka conversion disorders) as well as the emergence of a growing number of specialists who practice at the intersection of neurology and psychiatry (4,5). More focus on the biologic underpinnings and novel treatment approaches are emerging, and it will be increasingly important to correctly characterize patients. Many may not be able to be diagnosed in EMUs owing to lack of proper insurance, lack of appropriate referral, …