Psychogenic non-epileptic seizures (PNES) are events resembling an epileptic seizure, but without the characteristic electrical discharges associated with epilepsy. PNES fall under the category of disorders known as functional neurological disorders (FND), also known as conversion disorders. A more recent term to describe these events is dissociative non-epileptic seizures. These are typically treated by psychologists or psychiatrists. PNES has previously been called pseudoseizures, psychogenic seizures, and hysterical seizures, but these terms have fallen out of favor. Incidence
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. 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. 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. 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.
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, 5–20% of people with PNES also have epilepsy. Frontal lobe seizures can be mistaken for PNES, though these tend to have shorter duration, stereotyped patterns of movements, and occurrence during sleep. 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.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). Additional clinical criteria are usually considered in addition to video-EEG monitoring when diagnosing PNES. By recording the event in question on video and EEG simultaneously, a clear diagnosis can usually be obtained.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.