Psychogenic non-epileptic seizures

Psychogenic non-epileptic seizures (PNES) are events resembling an epileptic seizure, but without the characteristic electrical discharges associated with epilepsy. They are of psychological origin, and are one type of non-epileptic seizure mimics. PNES are also known less specifically as non-epileptic attack disorder (NEAD) and functional neurological symptom disorder. Psychogenic non-epileptic seizures (PNES) are events resembling an epileptic seizure, but without the characteristic electrical discharges associated with epilepsy. They are of psychological origin, and are one type of non-epileptic seizure mimics. PNES are also known less specifically as non-epileptic attack disorder (NEAD) and functional neurological symptom disorder. People present with episodes that resemble seizures, and most have received a diagnosis of epilepsy and treatment for it. 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). Most people with PNES (75%) are women, with onset in the late teens to early twenties being typical. A number of studies have also reported a high incidence of abnormal personality traits or personality disorders in people with PNES such as borderline personality. However, again, when an appropriate control group is used, the incidence of such characteristics is not always higher in PNES than in similar illnesses arising due to organic disease (e.g., epilepsy). Other risk factors for PNES include having a diagnosis of epilepsy, having recently had a head injury or recently undergone neurosurgery. The cause is by definition psychological, and can be categorized into several psychiatric diagnoses. In the vast majority of people, the production of seizure-like symptoms is not under voluntary control, meaning that the person is not faking; symptoms which are feigned or faked voluntarily would fall under the categories of factitious disorder or malingering. 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. 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. EEG-video monitoring will usually answer the following questions: