Functionality of symptoms and interpersonal communication in home video recordings of functional/dissociative versus...

Conceptualizing functional/dissociative seizures (FDS) as resulting from dissociation, or conversion, we hypothesized that, compared to epileptic seizures (ES), FDS should carry more symbolic or communicative content and that this would allow observers to distinguish FDS from ES.

Three independent, epileptologically naive raters evaluated home videos of patients with confirmed diagnoses of either FDS or ES using a standardized form. The focus of the ratings was explicitly not on seizure semiology, but on verbal and nonverbal behavior, the role of proxies, interaction patterns, communication, emotional tone, symbolic content, and situational context.

Of 598 home videos available from 183 patients, 215 ES and 95 FDS videos were suitable for analysis. No explicit symbolic communication was identified. FDS showed more passive, withdrawn behavior, and the postictal phase-captured more often than the ictal period-was particularly helpful for distinguishing FDS from ES. Interrater reliability was moderate. Features observed more commonly in FDS included closed eyes, recumbent posture, repetitive movements, reduced eye contact, responses to caring behavior, and occurrence in private settings. Raters perceived greater emotional distress in FDS and reported more distress watching these videos. Logistic regression based on all ratings correctly classified 94% of ES but only 32% of FDS.

Home video analysis captures important contextual and behavioral features of FDS and ES. The differential diagnostic reliability of lay raters' perceptions is limited. Findings suggest that FDS comprise passive rather than active appellative communication, likely reflecting emotional regulation processes. In contrast, in the home videos studied, ES patients exhibit greater postictal awareness and interaction than FDS patients, pointing to the relevance of the postictal phase for discriminating both seizure types. The results emphasize integrating environmental context and patient-caregiver interactions before, during, and after seizures to understand the functional significance of FDS in naturalistic, nonclinical settings.