Application of the International Classification of Cognitive Disorders in Epilepsy (IC-CoDE) to frontal lobe epilepsy using multicenter data

Kayela Arrotta; Sara J Swanson; Julie K Janecek; Marla J Hamberger; William B Barr; Sallie Baxendale; Carrie R McDonald; Anny Reyes; Bruce P Hermann; Robyn M Busch

doi:10.1016/j.yebeh.2023.109471

Application of the International Classification of Cognitive Disorders in Epilepsy (IC-CoDE) to frontal lobe epilepsy using multicenter data

Epilepsy Behav. 2023 Nov:148:109471. doi: 10.1016/j.yebeh.2023.109471. Epub 2023 Oct 20.

Authors

Affiliations

¹ Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA. Electronic address: arrottk@ccf.org.
² Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, USA.
³ Department of Neurology, Columbia University, New York, NY, USA.
⁴ Department of Neurology, NYU Grossman School of Medicine, New York, NY, USA.
⁵ Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.
⁶ Center for Multimodal Imaging and Genetics, University of California, San Diego, CA, USA; Department of Radiation Medicine and Applied Sciences, University of California, San Diego, CA, USA.
⁷ Department of Neurology, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA.
⁸ Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA.

PMID: 37866248
DOI: 10.1016/j.yebeh.2023.109471

Abstract

Rationale: The International Classification of Cognitive Disorders in Epilepsy (IC-CoDE) was recently introduced as a consensus-based, empirically-driven taxonomy of cognitive disorders in epilepsy and has been effectively applied to patients with temporal lobe epilepsy (TLE). The purpose of this study was to apply the IC-CoDE to patients with frontal lobe epilepsy (FLE) using national multicenter data.

Methods: Neuropsychological data of 455 patients with FLE aged 16 years or older were available across four US-based sites. First, we examined test-specific impairment rates across sites using two impairment thresholds (1.0 and 1.5 standard deviations below the normative mean). Following the proposed IC-CoDE guidelines, patterns of domain impairment were determined based on commonly used tests within five cognitive domains (language, memory, executive functioning, attention/processing speed, and visuospatial ability) to construct phenotypes. Impairment rates and distributions across phenotypes were then compared with those found in patients with TLE for which the IC-CoDE classification was initially validated.

Results: The highest rates of impairment were found among tests of naming, verbal fluency, speeded sequencing and set-shifting, and complex figure copy. The following IC-CoDE phenotype distributions were observed using the two different threshold cutoffs: 23-40% cognitively intact, 24-29% single domain impairment, 13-20% bi-domain impairment, and 18-33% generalized impairment. Language was the most common single domain impairment (68% for both thresholds) followed by attention and processing speed (15-18%). Overall, patients with FLE reported higher rates of cognitive impairment compared with patients with TLE.

Conclusions: These results demonstrate the applicability of the IC-CoDE to epilepsy syndromes outside of TLE. Findings indicated generally stable and reproducible phenotypes across multiple epilepsy centers in the U.S. with diverse sample characteristics and varied neuropsychological test batteries. Findings also highlight opportunities for further refinement of the IC-CoDE guidelines as the application expands.

Keywords: Cognition; Epilepsy; Frontal lobe epilepsy; Neuropsychology; Phenotypes.

Publication types

Multicenter Study

MeSH terms

Cognition
Cognition Disorders* / diagnosis
Cognition Disorders* / etiology
Cognitive Dysfunction* / diagnosis
Cognitive Dysfunction* / etiology
Epilepsy, Frontal Lobe* / complications
Epilepsy, Frontal Lobe* / diagnosis
Epilepsy, Frontal Lobe* / psychology
Epilepsy, Temporal Lobe* / complications
Epilepsy, Temporal Lobe* / psychology
Executive Function
Humans
Neuropsychological Tests