The terminology used to describe PNES is variable and at times confusing. A number of terms have been used, including pseudoseizures, nonepileptic seizures, nonepileptic events, psychogenic seizures, and hysterical seizures. Strictly speaking, terms such as pseudoseizures, nonepileptic seizures, and nonepileptic events include both psychogenic and nonpsychogenic (i.e., organic) episodes that mimic epileptic seizures. Examples of nonpsychogenic episodes include syncope (the most common); paroxysmal movement disorders (e.g., dystonia); cataplexy; complicated migraines; and, in children, breath-holding spells and shuddering attacks. Terms such as psychogenic or hysterical seizures, on the other hand, refer to a subset of nonepileptic seizures with the connotation of a psychological origin. Use of the term hysteria has long since fallen into disfavor. The term psychogenic seizures could possibly be interpreted as epileptic seizures triggered or exacerbated by a psychological factor. For these reasons, PNES is the preferred term (3) and is used throughout this chapter.

The erroneous diagnosis of epilepsy is relatively common. Approximately 25% of patients previously diagnosed with epilepsy and who are not responding to antiepileptic drug (AED) therapy are found to be misdiagnosed, both in epilepsy referral clinics (4,5) and in epilepsy monitoring units (1). Most patients misdiagnosed with epilepsy are eventually shown to have PNES (1,2) or, more rarely, syncope (6,7). Occasionally, other paroxysmal conditions can be misdiagnosed as epilepsy, but PNES are by far the most common condition, followed by syncope. Often, electroencephalograms (EEGs) that are interpreted as providing evidence for epilepsy contribute to this misdiagnosis (4,6,8). As is true with other chronic conditions (e.g., MS), whenever a wrong diagnosis of epilepsy has been given, it can be very difficult to “undo.” Unfortunately, once the diagnosis of “seizures” has been made, it becomes easily perpetuated without being questioned, which explains the usual diagnostic delay (9,10) and associated cost (11,12). It is disconcerting that despite the ability to render a diagnosis of PNES with near-certainty, the delay in diagnosis remains long, at about 7 to 10 years (9,10), indicating that neurologists may not have a high enough index of suspicion when AED treatment fails. This chapter begins by reviewing the steps involved in making that diagnosis and then turns to management considerations.

PNES are initially suspected in the clinic on the basis of history and examination. A number of “red flags” are useful
in clinical practice and should raise the suspicion that seizures may be psychogenic rather than epileptic. Of course, resistance to AEDs can be the first clue and is usually the reason for referral to an epilepsy center. Most (approximately 80%) of the patients with PNES have been treated with AEDs for some time before the correct diagnosis is made (13). This is because a diagnosis of epilepsy is usually based solely on history and may be difficult, especially for nonneurologists (e.g., emergency department physicians and primary care physicians). A very high frequency of episodes that are completely unaffected by AEDs (i.e., no difference whether on or off medication) should also suggest the possibility of a psychogenic etiology. The presence of specific triggers that are unusual for epilepsy can be very suggestive of PNES, and this should be asked specifically when obtaining the history. For example, emotional triggers (“stress” or “getting upset”) are commonly reported in patients with PNES. Other triggers that are suggestive of PNES include pain, certain movements, sounds, and lights, especially if they are alleged to consistently precipitate a “seizure.” The circumstances under which attacks occur can be very helpful. Like other psychogenic symptoms, PNES tend to occur in the presence of an “audience,” and, for example, occurrence in a physician’s office or waiting room may be predictive of a psychogenic etiology (14). Similarly, PNES tend not to occur in sleep, although they may seem to and may be reported as such (15,16).

If the historian and witnesses are astute enough, the detailed description of the spells often includes characteristics that are inconsistent with epileptic seizures. In particular, some characteristics of the motor (“convulsive”) phenomena are associated with PNES (see “Electroencephalogram-Video Monitoring”). However, witnesses’ accounts are rarely detailed enough to describe the episodes accurately; in fact, even seizures witnessed by physicians and thought to be epileptic often turn out to be PNES. The patient’s medical history can be useful as well. Although it has not been documented, coexisting poorly defined and “fashionable” (probably psychogenic) conditions, such as fibromyalgia, chronic pain, irritable bowel, or chronic fatigue, are associated with psychogenic symptoms. In a population referred for refractory seizures, a history of fibromyalgia or chronic pain has a strong association with a diagnosis of PNES (14). Similarly, a florid review of systems suggests somatization. A psychosocial history with evidence of maladaptive behaviors or associated psychiatric diagnoses should raise the level of suspicion of PNES. The examination, paying particular attention to mental status evaluation, including general demeanor and appropriate level of concern, overdramatization, and hysterical features, can be very telling, often uncovering such histrionic behavior as “give-way” weakness or “tight-roping.” Performing the examination can, in itself, act as an “induction” in suggestible patients, making a spell more likely to occur during the history taking or examination.

By contrast, the presence of certain symptoms argues in favor of epileptic seizures and should warrant caution. These include significant postictal confusion, incontinence, and, most important, significant injury (17, 18, 19, 20, 21). Although some injuries have been reported in PNES, data that describe injuries in patients with PNES are based largely on patients’ self-reports (22). In particular, tongue biting is highly specific to generalized tonic-clonic seizures (18) and thus is a very helpful sign when present.