Psychogenic non-epileptic seizure

Individuals with PNES present with episodes that resemble epileptic seizures, and most have received a diagnosis of epilepsy and treatment for it.[3][4][5][6] Most commonly the episodes in question are convulsive (whole body shaking) and resemble generalized tonic-clonic (“grand mal”) seizures, but they can be less dramatic and mimic milder types of seizures (partial seizures, absence seizures, myoclonic seizures).

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.[6] The production of seizure-like symptoms is not under voluntary control, meaning that the person is not faking;[3][7] symptoms which are feigned or faked voluntarily would fall under the categories of factitious disorder or malingering.[8] Most individuals with PNES (75%) are women, with onset in the late teens to early twenties being typical.[9]

According to the Diagnostic and Statistical Manual of Mental Disorders (version 5) the criteria for receiving a diagnosis of PNES are:[10]

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."[10]

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 non-epileptic seizures, including syncope, migraine, vertigo, anoxia, hypoglycemia, and stroke. However, between 5-20% of people with PNES also have epilepsy.[11] Frontal lobe seizures can be mistaken for PNES, though these tend to have shorter duration, stereotyped patterns of movements and occurrence during sleep.[9] Next, an exclusion of factitious disorder (a subconscious somatic symptom disorder, where seizures are caused by psychological reasons) and malingering (simulating seizures intentionally for conscious personal gain – such as monetary compensation or avoidance of criminal punishment) is conducted. Finally other psychiatric conditions that may superficially resemble seizures are eliminated, including panic disorder, schizophrenia, and depersonalisation disorder.[9]

The most definitive test to distinguish epilepsy from PNES is long term video-EEG monitoring, with the aim of capturing one or two episodes on both video recording and EEG simultaneously (some clinicians may use suggestion to attempt to trigger an episode).[12] Additional clinical criteria are usually considered in addition to video-EEG monitoring when diagnosing PNES.[13] By recording the event in question on video and EEG simultaneously, a clear diagnosis can usually be obtained.[14]

Laboratory testing can detect rising blood levels of serum prolactin if samples are taken in the right time window after most tonic-clonic or complex partial epileptic seizures. However, due to false positives and variability in results, this test is relied upon less frequently.[9]

An understanding of the new diagnosis is crucial for their treatment, which requires their active participation.[15] 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

Psychotherapy is the most frequently used treatment, which might include cognitive behavioral therapy or therapy to retrain the physical symptoms and allow the individual to regain control of the attacks. There is also some evidence supporting selective serotonin reuptake inhibitor antidepressants.[16] Mental health professionals typically show little interest in this category of psychiatric diseases and people frequently find themselves stuck between psychiatry and neurology with no one to turn to for treatment.[3][17]

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 social security at three-year follow-up.[18] 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,[19] social status,[20] greater educational attainments,[21] younger age of onset and diagnosis,[21] attacks with less dramatic features,[21] and fewer additional somatoform complaints.[21]

The number of people with PNES ranges from 2 to 33 per 100,000.[22] Although the rate in the general population are difficult to determine, it remains the most frequent non-epileptic condition seen in epilepsy centers. At epilepsy centers PNES is found in 20-40% of inpatients. Like other somatic symptom disorders, PNES are most common in young adults and women.[23] The number of people with PNES in those with functional neurological disorder is higher.[24]

Hystero-epilepsy is a historical term that refers to a condition described by 19th-century French neurologist Jean-Martin Charcot[26] where people with neuroses "acquired" symptoms resembling seizures as a result of being treated on the same ward as people who genuinely had epilepsy.

PNES rates and presenting symptoms are somewhat dependent on the culture and society. In some cultures, they, like epilepsy, are thought of as a curse or a demonic possession.[27] In cultures with a solid establishment of evidence-based medicine, they are considered a subtype of a larger category of psychiatric disease.

The use of older terms including pseudoseizures and hysterical seizures are discouraged.[28] 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.[29][30]

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 DSM 5, patients presenting with PNES may meet the criteria for functional neurological disorder and in some cases, somatic symptom disorder, whilst in ICD 10 it may meet the criteria for a conversion disorder.[9]