Psychogenic non-epileptic seizure

Psychogenic non-epileptic seizures (PNES), which have been more recently classified as functional seizures, are events resembling an

The number of people with PNES ranges from 2 to 33 per 100,000.[6] PNES are most common in young adults, particularly women.^[6] The prevalence for PNES is estimated to make up 5–20% of outpatient epilepsy clinics; 75–80% of these diagnoses are given to female patients and 83% are to individuals between 15 and 35 years old.^[7]

Children

PNES are seen in children after the age of eight, and occur equally among boys and girls before puberty. Diagnostic and treatment principles are similar to those for adults, except that in children there is a broader differential diagnosis of seizures so that other possible diagnoses specific to children may be considered.^[8]

Signs and symptoms

Individuals with PNES present with episodes that resemble epileptic seizures, and most have received a diagnosis of epilepsy and treatment for it.^{[9][10][11][12]} PNES episodes are nearly indistinguishable from epileptic seizures. The main differences between a PNES episode and an epileptic seizure is the duration of episodes. Epileptic seizures typically last between 30 and 120 seconds depending on the type, while PNES episodes typically last for two to five minutes.^[13]

Causes and risk factors

The cause of PNES has not yet been established. One hypothesis is that they are a learned physical reaction or habit the body develops, similar to a reflex. The individual does not have control of the learned reaction, but this can be retrained to allow the patient to control the physical movements again.^[12] The production of seizure-like symptoms is not under voluntary control, meaning that the person is not faking;^[9][14] symptoms which are feigned or faked voluntarily would fall under the categories of factitious disorder or malingering.^[15]

Risk factors for PNES include having a history of head injury, and having a diagnosis of epilepsy.^[16] Approximately 10–30% of people diagnosed with PNES also have an epilepsy diagnosis. People diagnosed with PNES commonly report physical, sexual, or emotional trauma, but the reported incidence of these events may not differ between PNES and epilepsy.^[17]

Diagnosis

According to the Diagnostic and Statistical Manual of Mental Disorders (version 5) the criteria for receiving a diagnosis of PNES are:^[18]

1. One or more symptoms of altered voluntary motor or sensory function.
2. Clinical findings provide evidence of incompatibility between the symptom and recognized neurological or medical conditions.
3. The symptom or deficit is not better explained by another medical or mental disorder.
4. The symptom or deficit causes clinically significant distress or impairment in social, occupational, or other important areas of functioning or warrants medical evaluation.

Additionally, the specific symptom type must be reported "with attacks or seizures".^[18]

Some individuals with PNES have carried an erroneous diagnosis of epilepsy. On average, it takes seven years to receive a proper diagnosis. The differential diagnosis of PNES firstly involves ruling out epilepsy as the cause of the seizure episodes, along with other organic causes of

Some features are more or less likely to suggest PNES but they are not conclusive and should be considered in the broader clinical picture. Features that are common in PNES but rarer in epilepsy include: biting the tip of the tongue, seizures lasting more than two minutes (easiest factor to distinguish), seizures having a gradual onset, a fluctuating course of disease severity, the eyes being closed during a seizure, and side to side head movements. Features that are uncommon in PNES include automatisms (automatic complex movements during the seizure), severe tongue biting, biting the inside of the mouth, and incontinence.[20]

If a person with suspected PNES has an episode during a clinical examination, there are a number of signs that can be elicited to help support or refute the diagnosis of PNES. Compared to people with epilepsy, people with PNES will tend to resist having their eyes forced open (if they are closed during the seizure), will stop their hands from hitting their own face if the hand is dropped over the head, and will fixate their eyes in a way suggesting an absence of neurological interference.^[20]

Treatment

Patient understanding of the new diagnosis is crucial for their treatment, which requires their active participation.^[24] There are a number of recommended steps to explain to people their diagnosis in a sensitive and open manner. A negative diagnosis experience may cause frustration and could cause a person to reject any further attempts at treatment. Eight points recommended to explain the diagnosis to the person and their caregivers are:

1. Reasons for concluding they do not have epilepsy
2. What they do have (describe FND)
3. Emphasize they are not suspected of "putting on" the attacks, and the symptoms are not "all in their head"
4. There may be no triggering "stresses"
5. Maintaining factors
6. May improve after correct diagnosis
7. Caution that
   anticonvulsant drug
   withdrawal should be done in conjunction with their physician
8. Describe treatment to help regain control of symptoms

Cognitive behavioral therapy[26]

Cognitive behavioral therapy (CBT) treatments for PNES typically target fear avoidance and work to reattribute patients' symptoms to psychosocial issues.

Retraining and Control Therapy (ReACT)

ReACT, while new and understudied, has shown extremely promising outcomes for reduction of PNES episodes in pediatric patients.^[27] This therapy focuses on the idea that PNES are caused by a learned physical reaction or habit the body develops, similar to a reflex. ReACT aims to retrain the learned reaction (PNES episodes) by targeting symptom catastrophizing and restoring sense of control over symptoms.

Prognosis

Functional seizures have been found to be as disabling and costly as epilepsy.^[28] Though there is limited evidence, outcomes appear to be relatively poor with a review of outcome studies finding that two-thirds of people with PNES continue to experience episodes and more than half are dependent on the Social Security program at three-year follow-up.^[24] This outcome data was obtained in a referral-based academic epilepsy center and loss to follow-up was considerable; the authors point out ways in which this may have biased their outcome data. Outcome was shown to be better in people with higher IQ,^[29] social status,^[30] greater educational attainments,^[31] younger age of onset and diagnosis,^[31] attacks with less dramatic features,^[31] and fewer additional somatoform complaints.^[31]

For individuals who pursue treatment for PNES, CBT has shown varying rates of success but it has been established as one of the most promising treatments to date.^[32] ReACT has shown reduction in symptoms by 100% seven days after treatment and 82% of individuals who completed the therapy remained symptom free for 60 days. A follow-up has not been done to see if the therapy retained its reduction of symptoms beyond the 60 days.^[27] In the Cognitive behavioural therapy for adults with dissociative seizures (CODES) trial, the largest regarding CBT treatment for PNES though found no significant reduction in monthly seizures compared to the control arm at 12 months, however there were significant improvements on a number of secondary outcomes, such as psychosocial functioning, and self-rated and clinician-rated global change.^[33] A secondary analysis of the CODES trial demonstrated improved frequency of functional seizures at 6 months with CBT.

History

Hystero-epilepsy is a historical term that refers to a condition described by 19th-century French neurologist

The etiology of FND was historically explained in the context of psychoanalytic theory as a physical manifestation of psychological distress and repressed trauma. There is very little supporting evidence for this theory, as there is little research.^[35]

The

The use of older terms including pseudoseizures and hysterical seizures are discouraged.[38] In the English language, the word "seizure" usually refers to epileptic events, so some prefer to use more general terms like "events", "attacks", or "episodes", as the term "seizures" may cause confusion with epilepsy.^[39][40]

PNES may also be referred to as "non-epileptic attack disorder" "functional seizures", "dissociative convulsions" or "dissociative non-epileptic seizures". These terms are more neutral as to cause, and given that a psychological cause cannot be identified in many cases, they may be more appropriate. Within