Psychogenic non-epileptic seizure (Functional seizures)

Psychogenic non-epileptic seizures (PNES) or functional seizures are events resembling an epileptic seizure, but without the characteristic electrical discharges associated with epilepsy.

A functional neurological disorder (FND), also known as conversion disorders, and dissociative non-epileptic seizures.

These are typically treated by psychologists or psychiatrists. 

The number of people with PNES ranges from 2 to 33 per 100,000.

PNES are most common in young adults, particularly women.

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.

Functional seizures 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.

Patients with PNES present with episodes that resemble epileptic seizures, and most have received a diagnosis of epilepsy and treatment for it.

Functional epileptic 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, while PNES episodes typically last for two to five minutes.

A hypothesis for functional seizures suggests it is a learned physical reaction or habit the body develops.

The production of seizure-like symptoms is not under voluntary control, meaning that the person is not faking.

Risk factors for PNES include having a history of head injury, and having a diagnosis of epilepsy.

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.

PNES are believed to be a manifestation of underlying psychological or emotional issues that result in neurological symptoms.

PNES may present with a wide range of seizure-like symptoms, including loss of consciousness, convulsions, muscle stiffness or twitching, and altered sensations. 

However, unlike epileptic seizures, PNES do not show changes on electroencephalogram (EEG) recordings that are typically seen with seizures.

Diagnosis of PNES is challenging because the symptoms and clinical findings can be very similar to those of epileptic seizures. 

Psychological testing and evaluation by a psychiatrist or psychologist can help identify any underlying emotional or psychological issues that may be contributing to the symptoms.

Treatment for PNES typically involves a combination of medication, psychotherapy and behavioral interventions to manage underlying psychological or emotional issues. 

Anti-seizure medications are not effective and may exacerbate symptoms. 

Treatment resolves on addressing underlying psychological or emotional factors that may be contributing to the seizures.

Diagnosis of PNES are:

symptoms of altered voluntary motor or sensory function.

Findings 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.

The specific symptom type must be reported with attacks or seizures.

Some patients with PNES have carried an erroneous diagnosis of epilepsy. 

On average, it takes seven years to receive a proper diagnosis of functional seizures.

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.

Frontal lobe seizures can be mistaken for PNES, but tend to have shorter duration, stereotyped patterns of movements, and occurrence during sleep.

The exclusion of factitious disorder: subconscious somatic symptom disorder, and malingering for conscious personal gain is conducted. 

Other psychiatric conditions may superficially resemble seizures are eliminated, including panic disorder, schizophrenia, and depersonalisation disorder.

The most definitive test to distinguish epilepsy from PNES is long term video-EEG monitoring.

Laboratory testing can detect rising blood levels of serum prolactin if samples are taken shortly after most tonic-clonic or complex partial epileptic seizures. 

Features common in PNES but rarer in epilepsy include: biting the tip of the tongue, seizures lasting more than two minutes, 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: automatic complex movements during the seizure, severe tongue biting, biting the inside of the mouth, and incontinence.

Patients 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.


Patient understanding of the new diagnosis is crucial for their treatment.

A negative diagnosis experience may could cause a person to reject any further attempts at treatment. 

Explaining the diagnosis, with 

emphasis they are not suspected of putting on the attacks, and the symptoms are not all in their head.

Psychotherapy is the most frequently used treatment: 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.

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) 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 by targeting symptom catastrophizing and restoring sense of control over symptoms.

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.

Outcomes are better in people with higher IQ, social status, educational attainments, younger age of onset and diagnosis, attacks with less dramatic features,and fewer additional somatoform complaints.

CBT is established as one of the most promising treatments.

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. 

In the largest trial of CBT 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.

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