Psychogenic Nonepileptic Seizures

Excerpt

Pseudoseizure is an older term for events that appear to be epileptic seizures but, in fact, do not represent the manifestation of abnormal excessive synchronous cortical activity, which defines epileptic seizures. They are not a variation of epilepsy but are of psychiatric origin. Other terms used in the past include hysterical seizures, psychogenic seizures, and others. The most standard current terminology is psychogenic nonepileptic seizures (PNES). Some advocate other terms such as psychogenic functional spells or psychogenic nonepileptic events, spells, or attacks. These terms reinforce the idea that the events are not epileptic seizures. A retrospective review of a small number of patients over a number of years revealed that dozens of different diagnostic terms were used to describe these events. Though established in use, the term pseudoseizure and others should be regarded as jargon, and the use of psychogenic nonepileptic seizures (or alternatively, spells) (PNES) is encouraged for clarity.

Distinguishing PNES from epileptic seizures may be difficult at the bedside even to experienced observers. In theory, almost any recurrent behavior may represent epileptic seizures. The evolution of epilepsy monitoring units and the ability to utilize simultaneous video and EEG recordings may be a key to diagnosis. Video electroencephalography (video-EEG) of a typical event showing the absence of epileptiform activity during the spell with a compatible history is regarded as the gold standard for diagnosis. Diagnostic delay of years with psychogenic nonepileptic seizures is common.

Treatment of PNES may be difficult, but it is clear that anti-epileptic drugs (AEDs) are of no benefit. In addition to unnecessary costs and the potential side effects of AEDs for these patients, life-threatening side effects such as respiratory depression may occur if psychogenic nonepileptic status epilepticus is treated with large dosages of benzodiazepines.