Psychogenic Nonepileptic Seizures

Psychogenic nonepileptic seizures (PNES), or pseudoseizures are paroxysmal episodes that resemble and are often misdiagnosed as epileptic seizures; however, PNES are psychological (i.e., emotional, stress-related) in origin.

Paroxysmal nonepileptic episodes can be either organic or psychogenic. Syncope, migraine, and transient ischemic attacks (TIAs) are examples of organic nonepileptic paroxysmal symptoms. This article covers only PNES.

The terminology on the topic has been variable and, at times, confusing. Various terms are used, including pseudoseizures, nonepileptic seizures, nonepileptic events, and psychogenic seizures. PNES has been the preferred term in the literature, but in practice, the term "seizures" is confusing to patients and families, so that it is probably best to replace it with more general terms that so not imply epilepsy, such as "attacks" or "events." ^[1]

PNES are common at epilepsy centers, where they are seen in 20-30% of patients referred for refractory seizures. PNES are probably also common in the general population, with an estimated prevalence of 2-33 cases per 100,000 population, which makes PNES nearly as prevalent as multiple sclerosis or trigeminal neuralgia.

Diagnostic Criteria (DSM-5)

By definition, PNES is a psychiatric disorder; more specifically it is a conversion disorder, which falls under the diagnostic category of somatic symptom disorders in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). According to the DSM-5 classification, neurological symptoms that are found, after appropriate neurological assessment, to be incompatible with neurological pathophysiology can fall under conversion disorder, factitious disorder, or malingering.

The specific DSM-5 criteria for conversion disorder are as follows : ^[18]

One or more symptoms of altered voluntary motor or sensory function

• Clinical findings provide evidence of incompatibility between the symptom and recognized neurological or medical conditions

• The symptom or deficit is not better explained by another medical or mental disorder

• The symptom or deficit causes clinically significant distress or impairment in social, occupational, or other important areas of functioning or warrants medical evaluation

PNES falls under the symptom subtype of “with attacks or seizures.”

Factitious disorder and malingering imply that the patient is purposely deceiving the physician (i.e., faking the symptoms). The difference between factitious disorder and malingering is that, in malingering, the reason for the deception is tangible and rationally understandable (albeit possibly reprehensible) such as avoiding military duty, avoiding work, obtaining financial compensation, evading criminal prosecution, or obtaining drugs. In factitious disorder, the motivation is a pathologic need for the sick role.

An important corollary is that malingering is not considered a mental illness, whereas factitious disorder is. As such there are no specific diagnostic criteria for malingering.

A generally accepted view is that most patients with PNES have conversion disorder, rather than malingering or factitious disorder.

Although the DSM-5 classification is simple in theory, knowing whether a given patient is faking it is nearly impossible. In some circumstances, intentional faking can be diagnosed only by catching a person in the act of faking (e.g., self-inflicting injuries, ingesting medications or eye drops to cause signs, putting blood in the urine to simulate hematuria).

Malingering may be underdiagnosed, partly because the diagnosis is essentially an accusation.

Psychogenic nonepileptic seizures (PNES) in perspective

The neurology and epilepsy literature on PNES often implies that PNES is a unique disorder. In reality, PNES is but one type of somatic symptom disorder. How the psychopathology is expressed (PNES, paralysis, diarrhea, or pain) is different only in the diagnostic aspects. Fundamentally, the underlying psychopathology, its prognosis, and its management are no different in PNES than they are in other psychogenic symptoms. Whatever the manifestations, psychogenic symptoms are a challenge in both diagnosis and management.

Psychogenic (i.e., nonorganic, functional) symptoms are common in medicine. By conservative estimates, at least 10% of all medical services are provided for psychogenic symptoms. These symptoms are also common in neurology, representing approximately 9% of all inpatient neurology admissions and probably an even higher percentage of outpatient visits. Common neurologic symptoms that are found to be psychogenic include paralysis, mutism, visual symptoms, sensory symptoms, movement disorders, gait or balance problems, and pain.

For several neurologic symptoms, signs or maneuvers have been described to help differentiate organic from nonorganic symptoms. For example, limb weakness is often evaluated by means of the Hoover test, for which a quantitative version has been proposed. Other examples are looking for give-way weakness and alleged blindness with preserved optokinetic nystagmus. More generally, the neurologic examination is often aimed to elicit symptoms or signs that do not make neuroanatomic sense (e.g., facial numbness affecting the angle of the jaw, gait with astasia-abasia or tight-roping).

Every medical specialty has its share of symptoms that can be psychogenic. In gastroenterology, these include vomiting, dysphagia, abdominal pain, and diarrhea. In cardiology, chest pain that is noncardiac is traditionally referred to as musculoskeletal chest pain, but it is probably psychogenic. Symptoms that can be psychogenic in other specialties include shortness of breath and cough in pulmonary medicine, psychogenic globus or dysphonia in otolaryngology, excoriations in dermatology, erectile dysfunction in urology, and blindness or convergence spasms in ophthalmology.

Pain syndromes for which a psychogenic component is likely include tension headaches, chronic back pain, limb pain, rectal pain, and sexual organ pain. Pain is, by definition, entirely subjective; therefore, to confidently say that pain is psychogenic is essentially impossible, and the term psychogenic is all but discredited in the pain literature. One could even argue that all pains are psychogenic; therefore, psychogenic pain is one of the most uncomfortable diagnoses to make. In addition to isolated symptoms, some consider certain syndromes to be at least partly and possibly entirely psychogenic (ie, without any organic basis). These controversial but fashionable diagnoses include fibromyalgia, fibrositis, myofascial pain, chronic fatigue, irritable bowel syndrome, and multiple chemical sensitivity.

For a review of this topic, see the Bibliography. ^{[16, 17, 7]}

Unlike epileptic seizures, PNES do not result from an abnormal electrical discharge from the brain; they are a physical manifestation of a psychological disturbance.

Familial pattern

Limited data suggest that conversion disorder frequently occurs in relatives of individuals with conversion disorder. Symptoms are often modeled from affected family members. Therefore, a thorough family history of medical conditions is essential. Case series show an increased risk in monozygotic but not dizygotic twins.

Nongenetic familial factors, such as incestuous sexual abuse in childhood, may be associated with an increased risk for conversion disorder. The conversion disorder may be the only mechanism for communication that remains available to the child or adolescent.

PNES are commonly misdiagnosed as epilepsy. It is by far the most frequent nonepileptic condition seen in epilepsy centers, where they represent 20-30% of referrals. ^[19] About 50-70% of patients become seizure-free after diagnosis, and about 15% also have epilepsy.

Similar to conversion disorders, PNES typically begin in young adulthood and occur more frequently in women (approximately 70% of cases) than in men. PNES can also occur in the elderly.

One should be particularly cautious in diagnosing PNES (and psychogenic symptoms in general) when the onset is in early childhood or old age. In these age groups, nonepileptic physiologic events may be more common than other conditions. For example, children may have parasomnias (e.g., night terrors), breath-holding spells, and shuddering attacks.

In general, outcomes in adults are tenuous. PNES severely affects the quality of life of affected patients. After having symptoms for ten years, more than half of all patients continue to have seizures and remain dependent on social security benefits.

Outcomes are improved with education, with an onset and diagnosis at a young age, with episodes characterized by nondramatic features, with few additional somatoform complaints, with low dissociation scores, and with low scores on the high-order personality dimensions (i.e., inhibition, emotional dysregulation, compulsivity).

Patients with the limp or catatonic type may have a better prognosis than those with the convulsive or thrashing type.

The duration of illness is probably the most important prognostic factor in PNES; the longer the patient has been treated for epilepsy, the worse the prognosis.

• Obtaining a definite diagnosis of PNES early in the course of disease is critical.

• The average delay in the diagnosis of PNES is long, indicating that the index of suspicion for psychogenic symptoms may not be high enough.

• In addition, an accurate diagnosis of PNES significantly reduces subsequent healthcare costs.

With PNES, outcomes are generally better in children and adolescents than in adults, probably because the duration of illness is shorter and the psychopathology or stressors are different in pediatric patients than in adults.

• A refusal to go to school and family discord may be significant factors.

• Serious mood disorders and ongoing sexual or physical abuse are common in children with PNES and should be investigated in every case.

Thorough patient education is critical and is the first step in treatment. Patients and their families must understand the diagnosis to comply with the recommendations of the psychiatric caregiver.

Written patient information about PNES is scarce but available. For additional information, visit the Comprehensive Epilepsy Program Web site of the University of South Florida.