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Updated: Dec 15, 2025

Behavioral Characterization of Pentylenetetrazole-induced Seizures: Moving Beyond the Racine Scale
Published on: July 8, 2025
Quantifying the burden of generalized tonic-clonic seizures in patients with drug-resistant epilepsy
Shehryar R Sheikh1, Nicholas Thompson2, Feride Frech3
1Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, USA.
Objective:
Compared to other seizure types, generalized tonic-clonic (GTC) seizures may be disproportionately related to increased morbidity, and reducing seizure frequency could translate into improvements across measures of morbidity in medically treated patients with drug-resistant epilepsy (DRE). The primary objective of this analysis was to quantify the burden of patients with DRE who experience GTC seizures (GTC+) compared to patients with DRE who do not experience GTC seizures (GTC-).
Methods:
Adult patients from the Cleveland Clinic Epilepsy Center-Neurological Institute from 2012-2016 with DRE with epilepsy for at least 1 year were eligible for inclusion and were divided into GTC ± groups based on whether the patient had experienced a GTC seizure in the year preceding the first visit. Epilepsy duration, comorbidities, antiepileptic drug use, patient-reported outcomes (PROs) and seizure type, frequency, and etiology were captured. Generalized linear models, negative binomial regression, logistic regression, and linear regression were used as appropriate for multivariate analyses.
Results:
A total of 379 patients met inclusion criteria and had data at 1-year follow-up after their baseline visit (192 GTC+ and 187 GTC-). Although DRE patients experiencing GTC seizures had fewer seizures per day over the preceding 6 months than those not experiencing GTC seizures, seizure severity and levels of depression and anxiety were greater. GTC+ patients who reported five or more seizures in the preceding 4 weeks had 82% lower odds (1-0.18 = 0.82) of working than patients with no seizures.
Significance:
Patients with DRE experience a significant burden and decreased quality of life. Multivariate analysis is necessary to understand the complex relationship between seizure type, frequency, and impact on health-related quality of life (HRQoL) and changes over time. Effective treatments to reduce the burden for DRE patients who experience GTC seizures continue to be needed.
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