Related Experiment Video
Updated: Feb 23, 2026

Behavioral Characterization of Pentylenetetrazole-induced Seizures: Moving Beyond the Racine Scale
Published on: July 8, 2025
Semiology of psychogenic nonepileptic seizures: An international cross-cultural study
Ali A Asadi-Pooya1, Kette Valente2, Ruda Alessi2
1Jefferson Comprehensive Epilepsy Center, Department of Neurology, Thomas Jefferson University, Philadelphia, PA, USA; Neurosciences Research Center, Shiraz Medical School, Shiraz University of Medical Sciences, Shiraz, Iran.
Purpose:
We compared the semiology of psychogenic nonepileptic seizures (PNES) between patients from the USA and Brazil. This international cross-cultural comparative study may expand understanding of PNES across the borders.
Methods:
We retrospectively investigated all patients with PNES admitted to one epilepsy center in the USA and one in Brazil. We classified their seizures into four classes: generalized motor, akinetic, focal motor, and subjective symptoms. All patients were interviewed by an epileptologist in both countries and were administered psychological assessment measures, including questions about PNES risk factors. For the statistical analyses, we compared patients from the two nations.
Results:
Eighty-nine patients (49 from the USA and 40 from Brazil) were studied. Patients from the two countries were not significantly different with regard to sex and age, but patients from Brazil had earlier age at onset (26years vs. 34years; P=0.004) and a significantly greater delay in diagnosis (9.9years vs. 5.6years; P=0.001). Some characteristics of PNES were different between the two groups; patients from the USA had generally more seizure types and more often reported subjective seizures (55% in the USA vs. 10% in Brazil; P=0.0001). Clinical and historical characteristics of the patients were not significantly different.
Conclusion:
Delay in diagnosis of PNES may represent a major factor in resource-limited countries. Large multicenter cross-cultural studies may reveal subtle but significant cross-cultural differences with respect to the semiological, clinical, and historical aspects of PNES; however, patients with PNES share more similarities than differences.
More Related Videos
Related Concept Videos
Seizures: Classification
Seizures are typically classified into two main categories: focal and generalized seizures.
Focal Seizures
Focal seizures originate from specific regions of the brain. These seizures are further sub-classified into two types:
Epilepsy and Seizures: Overview
Various factors can trigger epilepsy, including genetic factors, brain damage, metabolic causes, and unknown etiology. Diagnosis of epilepsy involves electroencephalography (EEG), which...
Psychological and Sociocultural Causes of Schizophrenia

