RESUMEN
OBJECTIVE: To look for evidence of peri-ictal social interaction in psychogenic nonepileptic seizures (PNES) and epileptic seizures exploring the notion of PNES as a form of nonverbal communication. METHODS: Video recordings of typical seizures experienced by patients with epilepsy and PNES were obtained in a naturalistic social setting (residential epilepsy monitoring unit). Video analysis by three nonexpert clinicians identified 18 predefined semiological and interactional features indicative of apparent impairment of consciousness or of peri-ictal responsiveness to the social environment with assessment of interrater reliability using Fleiss κ. Features were compared between epileptic seizures and PNES. RESULTS: One hundred eighty-nine seizures from 50 participants (24 epilepsy, 18 PNES, eight combined) were analyzed. At least fair (κ > 0.20) interrater agreement was achieved for 14 features. The PNES and epileptic seizures compared were of similar severity in terms of ictal impairment of consciousness (κ = 0.34, odds ratio [OR] = 1.11, 95% confidence interval [CI] = 0.62-1.96) and responsiveness (κ = 0.52, OR = 1.01, 95% CI = 0.55-1.86). PNES were more likely to be preceded by attempts to alert others (κ = 0.52, OR = 12.4, 95% CI = 3.2-47.7, P < .001), to show intensity affected by the presence of others (κ = 0.44, OR = 199.4, 95% CI = 12.0-3309.9, P < .001), and to display postictal behavior affected by the presence of others (κ = 0.35, OR = 91.1, 95% CI = 17.2-482.1, P < .001). SIGNIFICANCE: Nonexpert raters can, with fair to moderate reliability, rate features characterizing ictal impairment of consciousness and responsivity in video recordings of seizures. PNES are associated with greater peri-ictal responsiveness to the social environment than epileptic seizures. These findings are consistent with a potential communicative function of PNES and could be of differential diagnostic significance.
