Abstracts

Rationale: The International Classification of Cognitive Disorders in Epilepsy (IC-CoDE), a consensus-based, empirically driven approach to cognitive diagnostics in epilepsy, produces stable phenotypes in adults with TLE and FLE across multiple centers. While the distribution of phenotypes has been examined, potential associations with demographic and disease variables have not been explored. The purpose of this study is to identify factors that may be associated with IC-CoDE phenotypes in adults with focal epilepsies.


Methods: This retrospective study obtained data from an IRB-approved neuropsychology registry for adults being treated for pharmaco-resistant focal epilepsy. Chi-square with Bonferroni adjustment for multiple comparisons and Kruskal-Wallis test with post hoc Dunn’s tests with adjusted p values examined characteristics as a function of IC-CoDE phenotypes (i.e., intact, single domain, bi-domain, generalized) separately in adults with TLE and FLE. Demographics included sex, race, education, age, and Area Deprivation Index (ADI). Epilepsy variables included history of GTC, MRI (normal or abnormal), MTS on MRI, MCD on MRI, side of seizure onset, number of ASMs, age at seizure onset, and duration of epilepsy. Depression and anxiety were assessed using the Beck self-report screening measures.


Results: A total of 867 patients met inclusion criteria (TLE=768, FLE=99). The distribution of phenotypes was similar between groups (X²=6.424, p=.09). In patients with TLE, several factors were associated with cognitive phenotypes: race (p< .001), education (p< .001), MTS on MRI (p=.03), side of seizure onset (p=.03), number of ASMs (p< .001), age at onset (p=.006), ADI (p< .001), and BDI (p< .001). Post hoc analyses indicate that intact cognition was associated with identifying as white/non-Hispanic, absence of MTS on MRI, and seizures originating from the non-dominant hemisphere. Those classified with intact cognition took fewer ASMs than other phenotypes, had later seizure onset than those with generalized impairment, and scored lower on the BDI and lived in less deprived environments (i.e., lower ADI score) than those with bi-domain or generalized impairment. Adults with TLE and generalized impairment had less formal education than the other three groups. In patients with FLE, a higher proportion of males had intact cognition, while a higher proportion of females had generalized impairment.