Behaviors mimicking seizures in institutionalized individuals with multiple disabilities and epilepsy: a video-EEG study.

We reviewed 824 video-EEG telemetry requests of institutionalized patients with epilepsy, searching for evaluations of "new seizure types" identified by staff (caregivers, teachers, therapists, LPNs, RNs). Of the 63 newly identified "seizure types," epilepsy was confirmed in 4 (6.3%); 59 represented nonepileptic events. Causes for diagnostic confusion in the profoundly retarded included stereotypic repeated blinking, swallowing, buccolingual movements, spontaneous grimacing, periods of apparent psychomotor arrest and increased muscle tone, dystonic posturing, and irascible personality emerging after reduction of sedatives. Three cases of "startle seizures" were due to dystonic posturing caused by the unexpected contact of body with water during bath. Episodes of decreased daytime alertness ("somnolence") were erroneously attributed to "absence seizures" in eight cases by staff supervising tasks requiring sustained attention (i.e., school, workshop). In less impaired patients, self-stimulation, self-abuse, and ataxia with falls were the more common diagnoses. Simulation of seizures, a somewhat uncommon finding in this population, was the diagnosis in 3 cases. All were high functioning and appeared to simulate seizures to avoid work. Our findings suggest that the de novo appearance of a "new seizure type" in these patients, particularly in cases with a well-established seizure pattern, is uncommon. Four patients in whom the "new event" was confirmed to be epileptic had preexisting secondarily generalized seizures. What the staff identified was the variable clinical progression of seizures probably due to medication changes. Different fragments of the seizure appear to have occurred at different times with variable intensity and duration. A single seizure type may have appeared to be a variety of attacks because of this fragmented presentation.