EpiTrack is a feasible tool for assessing attention and executive functions in patients with refractory epilepsy

Abstract

Objective: The purpose of this cross-sectional retrospective study was to utilize EpiTrack to assess cognitive performance within the domain of attention and executive functions in patients with refractory epilepsy in consideration for treatment interventions either with antiepileptic drug (AED) changes and/or neuromodulation therapies. We also aimed to identify the relevant clinical and treatment factors possibly affecting EpiTrack performance.

Methods: The patient group consisted of 95 consecutive refractory epilepsy patients who were evaluated with EpiTrack. Based on their EpiTrack performance, the patients could be categorized as cognitively unimpaired, mildly, or severely impaired. The patients were also divided into three groups based on the planned treatment modification: AED group (n = 38) with only AED treatment, vagal nerve stimulation (VNS) group (n = 40) and deep-brain stimulation (DBS) group (n = 17). However, the effect of planned interventions was not the subject of this study. We retrospectively reviewed the medical records for detailed clinical characterization.

Results: EpiTrack performance was severely impaired in 48 (50.5%), mildly impaired in 22 (23.2%) and unimpaired in 25 (26.3%) of the patients. The DBS group had significantly lower EpiTrack scores (mean (SD) and median, 25.5 (4.81) and 27.0, respectively) compared to the AED group (28.6 (6.2) and 30.0, respectively, p = 0.049). Sixty-three (66.3%) of the whole study population had more than 2 AEDs. When comparing EpiTrack scores between patient groups based on the number of AEDs administered, there was a trend toward better performance in EpiTrack with 2 AEDs as compared to 3-4 AEDs.

Conclusions: Deficits in attention and executive functions were frequent among patients with refractory epilepsy. Deficits were evident in all three treatment groups being most severe in the DBS group reflecting the patient selection. Furthermore, the effect of AED burden on executive functions was remarkable since two thirds of the patients had more than two AEDs and the deficits were more prominent among those with a higher AED burden. These results highlight the benefits of a feasible screening tool such as EpiTrack for assessing attention and executive functions when optimizing the treatment effects of neurostimulation therapies on cognition, and when evaluating the impacts of the AED burden.

Keywords: Antiepileptic drug; Drug-resistant epilepsy; EpiTrack; Executive functions; Neurostimulation.