Cardiovascular risk factors (CVRFs) are known to create a burden on the vasculature of frontal subcortical networks that regulate attention, executive functioning, and aspects of memory. Temporal lobe epilepsy (TLE) patients with comorbid CVRFs have an elevated risk of cognitive problems, but the relative contributions from CVRF to these networks dysfunctions post-surgically are largely unexplored (Husein et al., 2021). Current research is limited to verbal memory outcomes in post-surgical left TLE patients (Reyes et al., 2020), which identified higher preoperative BMI and blood glucose (BG) levels as the greatest predictors of decline. The current study expanded upon previous work to highlight the contribution of a wider array of measured CVRFs to an array of neuropsychological tests. We aimed to identify and dissociate the specific causative effects from broader preoperative indicators in a cohort of anterior temporal lobectomy (ATL) patients.

Sixty-five early and middle-aged adults (mean age at surgery 40.26) with a history of refractory TLE (27 right-hemisphere, 38 left-hemisphere) underwent presurgical and one-year postsurgical neuropsychological testing. Cognitive decline was calculated using reliable change indices that accounted for possible testing practice effects (RCI-PE; Iverson, 2001). A modified version of an established cardiovascular risk score was used to classify patients based on preoperative CVRF burden (Tai et al., 2023; Reyes et al. 2020). Factors of interest included fasting BG level, magnetic resonance imaging (MRI) evidence of cerebrovascular disease, body mass index (BMI), and smoking status. More than half of the cohort was diagnosed and/or treated for at least one CVRF (57%), and 18% had four or more CVRFs. Twenty-three percent of the group had hypertension, 25% were former (20+ pack years) or current tobacco users, and 33.8% had a BMI consistent with obesity.

Postoperative seizure frequency was not associated with CVRF burden. Higher CVRF burden was associated with reliable changes in semantic fluency (p=.01) and aspects of verbal memory (p=.05) for the entire cohort. These relationships were nonsignificant after controlling for preoperative test scores, surgery age, presence of MTS, and side of surgical resection. However, word-list memory declines remained significantly associated with CVRF burden. Changes in attention and executive functioning were not significant.

The data supports the possibility that there are specific relationships between CVRF burden and neurocognitive outcomes. We demonstrated two such relationships of semantic fluency and verbal memory. However, CVRF burden and neuropsychological measures typically associated with frontal subcortical network dysfunction were nonsignificant. When moderating effects were considered, aspects of verbal memory remained significant, while semantic fluency diminished. This indicates that larger sample sizes are needed to disentangle and clarify complex relationships and interactions between CVRF burden and specific neuropsychological variables.