November 4, 2022

Epilepsy Center Characteristics and Geographic Region Influence Presurgical Testing in the United States

Abstract found on Wiley Online Library

Objective: Persons with drug-resistant epilepsy may benefit from epilepsy surgery and should undergo presurgical testing to determine potential candidacy and appropriate intervention. Institutional expertise can influence use and availability of evaluations and epilepsy surgery candidacy. This census survey study aims to examine the influence of geographic region and other center characteristics on presurgical testing for medically intractable epilepsy.

Methods: We analyzed annual report and supplemental survey data reported in 2020 from 206 adult epilepsy center directors and 136 pediatric epilepsy center directors in the United States. Test utilization data were compiled with annual center volumes, available resources, and U.S. Census regional data. We used Wilcoxon rank-sum, Kruskal-Wallis, and chi-square tests for univariate analysis of procedure utilization. Multivariable modeling was also performed to assign odds ratios of significant variables.

Results: The response rate was 100% with individual element missingness less than 11% across 342 observations undergoing univariate analysis. 278 complete observations were included in the multivariable models and significant regional differences were present. For instance, compared to centers in the South, those in the Midwest used neuropsychological testing (OR 2.87, 95% CI 1.2 – 6.86, p = 0.018) and FDG-PET (OR 2.74, 95% CI 1.14- 6.61, p = 0.025) more commonly. For centers in the Northeast (OR 0.46, 95% CI 0.23-0.93, p = 0.031) and West (OR 0.41, 95% CI 0.19-0.87, p = 0.022), odds of performing SPECT was lower by nearly 50% compared to those in the South. Center accreditation level, demographics, volume and resources were also associated with varying individual testing rates.

Significance: Presurgical testing for drug resistant epilepsy is influenced by U.S. geographic region and other center characteristics. These findings have potential implications for comparing outcomes between U.S. epilepsy centers and may inject disparities in access to surgical treatment.