Psychogenic Nonepileptic Seizures

Excerpt

Psychogenic nonepileptic seizures (PNES) are relatively common but poorly understood and often misdiagnosed as epilepsy, which can lead to unnecessary procedures and treatments along with the possibility of failure to engage patients in necessary behavioral health care. Despite a superficial resemblance to epilepsy, in PNES, the underlying cause has long been considered to be psychological. However, increasingly integrated theories of causation invoking genetics, environmental factors, temperament, and early childhood experiences are being proposed. Rarely is a nonepileptic event intentional, in which case it could be due to factitious disorder or malingering, but by definition, PNES themselves are never intentional.

"Pseudoseizure" is a now-outmoded term for paroxysmal events that appear to be epileptic seizures but do not arise from the abnormal excessive synchronous cortical activity that defines an epileptic seizure. Patients and healthcare practitioners alike are prone to misinterpret "pseudoseizure" as indicating that the patient is "faking" or otherwise feigning the events when, in fact, the events are involuntary behavioral responses to underlying psychological triggers or stresses. Other terms used in the past that should now be avoided are hysterical seizures, functional seizures, stress seizures, and others.

Distinguishing PNES from epileptic seizures may be difficult at the bedside, even for experienced clinicians. Indeed, some researchers have characterized PNES as occupying a no-man's land at the intersection between Neurology and Psychiatry. Diagnostic delay of years with PNES is common. Video electroencephalography (video-EEG) of a typical event showing the absence of epileptiform activity during the spell in the setting of a compatible history is the gold standard for diagnosis. Between 20% and 40% of patients referred to epilepsy monitoring units for difficult-to-control seizures are ultimately found to have PNES. A recently reported pediatric series examined 15 years of video-EEG monitoring and found that the final diagnosis was PNES in nearly 20% of monitored individuals; eventual discontinuation of antiseizure medication (ASM) on the grounds of initial misdiagnosis was necessary for nearly 25%.

Correct diagnosis is imperative for the successful treatment of PNES. Still, misdiagnosis is common, especially among primary care and emergency physicians, nearly two-thirds of whom reported their belief that video-EEG is not needed for diagnostic confirmation in a recent study. A comprehensive history and examination are vital steps toward a correct diagnosis. Consultation with neurology is nearly always beneficial; admission to an epilepsy monitoring unit for video-EEG analysis is almost always required. Referral to a comprehensive epilepsy center may be helpful in challenging cases.

The diagnosis of PNES needs to be conveyed to the patient effectively and empathically; doing otherwise carries a non-trivial risk of prompting confusion, anger, or resentment, any or all of which can then exacerbate PNES symptomatology. Diagnostic disclosure is particularly delicate if a given patient was previously diagnosed with epilepsy, and patients with a history of trauma or abuse can easily be re-traumatized by a clumsily rendered diagnosis. Above all, the clinician must acknowledge and underscore that help is available for the patient's symptoms, that these symptoms are real, and that symptoms represent a source of distress to the patient, family, and friends.

Treatment of PNES may be complex, but it is clear that ASMs are of no benefit, and they may cause harm.ASMs should be discontinued unless they are in use to manage concomitant epilepsy, chronic pain, or mood disorders; continuation of ASMs after the PNES diagnosis has been made is associated with poor outcomes. Psychotherapy is effective and can improve seizure frequency, overall psychosocial functioning, and health-related quality of life.