Abstracts

Rationale:
Epilepsy is diagnosed in 10-50% of patients with psychogenic nonepileptic spells (PNES). Although the semiology of PNES and epileptic seizures (ES) overlaps in some patients, the nonepileptic events may have more demonstrative and hyperkinetic phenotype than ES in the same patients. We used the kinetic classification of PNES previously developed by our group to characterize nonepileptic events in patients with mixed disorder and determine if the motor signature of PNES predicts a co-existent epilepsy type in these patients.
Method:
All consecutive patients with co-existent PNES and ES treated at the University of Nebraska Medical Center, a level 4 epilepsy center, from January 2011 to April 2017 were identified from the log of continuous video EEG recordings maintained at the Epilepsy Monitoring Unit. The video segments of all nonepileptic events in patients with confirmed ES were reviewed by an epileptologist and neuropsychologist and were assigned one of seven previously developed categories of PNES defined by the constellation of specific sensory and motor signs. Patients with PNES types manifesting with isolated sensory changes were excluded. The groups of patients with mixed disorder with hypokinetic or hyperkinetic PNES were compared with respect to their clinical characteristics and their association with the most common ES types (i.e., focal temporal, focal frontal, and generalized) using Fisher’s Exact tests.
Results:
The prevalence of co-existing PNES and ES in patients with confirmed PNES was 13.5 %. Among 43 patients with mixed disorder (mean age 36, interquartile range (IQR) 26-45), 27.9 % were male. A large minority of all patients (39.5%) had confirmed temporal epilepsy while the remaining were diagnosed with either focal frontal (26%), generalized (26%), or other (9%) epilepsies. Thirty patients (77%) had PNES with hypokinetic phenotype and were receiving a median of 3 (IQR 2-4) anticonvulsants, compared to a median of 2 (IQR 2-3) in hyperkinetic phenotype patients (p = 0.06). There was no significant association between the ES type and hypokinetic or hyperkinetic status of PNES; however, the group with co-existing focal frontal epilepsy had a higher percentage of hyperkinetic status patients (45%) than either the focal temporal (12%) or generalized (18%) sets.
Conclusion:
In patients with mixed disorder, the prevalence of PNES with hypokinetic semiology surpasses that of hypokinetic phenotype in focal temporal, focal frontal, and generalized epilepsy syndromes. Furthermore, the motor phenotype of PNES does not appear to be associated with the type of co-existing ES.
Funding:
:O. Taraschenko received grant support from the American Epilepsy Society Junior Investigator Research Award.