Psychogenic, Nonepileptic Seizures Associated with Video‐EEG–Verified Sleep

Abstract

Summary:Purpose: Nonepileptic seizures (NES) are expressions of a psychiatric disease state, usually conversion disorder, that mimic epileptic seizures (ES) but are not associated with the neurophysiologic changes of epilepsy. Conversion has not been demonstrated to emerge from the sleeping state. Emergence out of sleep is usually considered a virtual exclusion criterion for NES, signifying the presence instead of ES. We sought to test this hypothesis.Methods: We retrospectively reviewed the video-EEG of all patients admitted to our epilepsy unit over a 3-year period, who were suspected of manifesting NES. We examined the relation between NES and the patients' sleep/wake state in this cohort.Two epileptologists blindly reviewed an intermixture of cases suspected to represent NES emerging out of sleep, together with control cases. Classification of each case was made independently.Results: We found that in a small minority of patients (<1%), NES began either while the patient was sleeping, or within several seconds of arousal, well before a plan to simulate a seizure could likely have been formulated in the wakeful state.Conclusions: In some cases, NES are not the product of the awake mind, but rather represent a psychiatric condition that can be manifest in sleep.

Pseudosleep events in patients with psychogenic non-epileptic seizures: prevalence and associations

“…The associations we found between a history of events during sleep and simple measures of psychopathology (mood disorder, parasuicide) suggest that if this is so then the mechanism is unlikely to be simple malingering, and that factors other than benefits may also be at work. In any event, malingering is not considered a usual aetiological factor for PNES, though hard data are lacking, 1 5 10 11 15-17 This view is supported by a recent study of PNES, 18 which showed that in a minority of patients, events began, if not straight from sleep, then almost immediately on arousal.…”

Frontal Lobe Seizures

“…Because frontal lobe seizures are associated with sleep, it would seem intuitive that events out of sleep would be unlikely to represent psychogenic NES. However, it may be difficult to distinguish whether an event occurs directly out of sleep or after a brief arousal [62]. EEG remains normal throughout NES or often shows muscle artifact.…”

Proposal for best practice in the use of video-EEG when psychogenic non-epileptic seizures are a possible diagnosis

“…If an attack arises shortly after a period of apparent sleep, the report should state whether this behavioural sleep is accompanied by EEG sleep phenomena or whether the EEG pattern was actually more consistent with wakefulness: if strictly defined, the observation of pre-ictal ‘pseudo-sleep’ has a high specificity for PNES (Benbadis et al, 1996). If an attack arises from EEG-documented sleep, stating the exact time EEG sleep phenomena are lost and how many seconds later the attack begins, can help to differentiate the attack from epileptic seizures which customarily arise abruptly from EEG-documented sleep (Orbach et al, 2003). The factual report may be supplemented by a screenshot of the EEG during the event (American Clinical Neurophysiology Society, 2016a; Fig.…”