Abstracts

Rationale: The definitive diagnosis of psychogenic non-epileptic seizures (PNES) requires the registration of an episode by video-EEG. However, this technique is not always available and have been proposed to characterize different semiological patterns, although there is no consensus at present. The aim of our study was to describe the clinical profile of the patients diagnosed with PNES and to characterize the semiological features of the episodes. Methods: Video-EEG recordings of patients with a confirmed diagnosis of PNES were retrospectively reviewed by two epileptologists. The clinical records were reviewed to collect demographic data, previous medical history, family history, MRI findings, the diagnosis and treatment before monitoring and the reasons to perform the test. The semiological features considered were: duration of the episodes, subjective symptoms, awareness, eye condition (opened vs closed), motor symptoms, unilateral o bilateral involvement, and the presence of crying or moaning. Groups of PNES with similar semiological features were established paying special attention to the motor behavior. Results: A total of 56 patients (19 men and 37 women) were included in this study. Twenty-two patients had previous diagnosis of psychiatric illness, 11 epilepsy diagnosed before the study and 3 patients had both, epilepsy and psychiatric illness. In most cases, video-EEG monitoring was indicated because the physician thought there were atypical features that should be investigated. Based on a semiological analysis we identified 6 groups: Major motor PNES (14,3%), that included irregular asymmetrical multifocal movements of trunk and extremities, abrupt clonic or myoclonic movements and pelvic thrashing and kicking movements. Minor motor PNES (3,6%), defined by dystonic posturing of at least one limb and/or pseudo-rhythmic movements of head and extremities, mimicking tremor. "Dialeptic" PNES (8,9%) we included episodes where patients remained staring, with open eyes, appearing to be disconnected from the environment. Pseudosyncope PNES (17,8%) included those episodes that clinically could resemble presyncope or syncope, being the apparent muscle weakness the common feature. Subjective PNES (28,6%) included episodes with subjective feelings such as dizziness, disconnection or sleepiness. Finally, Mixed PNES (26,8%) included episodes that were composed of several phases, each one with different semiological features. Separately, each phase could be classified in any of the other 5 types of events. The sequence of semiological features was not consistent between episodes. Conclusions: The history is essential to suspect PNES. Although the bizarre semiological features make more difficult to describe types of PNES than in epileptic seizures, we think that it is possible to identify some groups according to their characteristics. This knowledge would be useful for their early identification, diagnosis and probably outcome.