Attention and Executive Functions Are the Most Vulnerable Cognitive Domains in Patients With Drug-Resistant Epilepsy Prior to Neurostimulation Therapy

Abstract

Background: Cognitive impairments are prevalent among patients with drug-resistant epilepsy (DRE) referred for neurostimulation therapies. However, the performance characteristics across various cognitive domains in this patient group are not well established. Objective: To analyze the characteristics and severity of cognitive impairment in patients with DRE referred for neurostimulation therapy, specifically vagus nerve stimulation (VNS) or deep brain stimulation of the anterior nucleus of the thalamus (ANT-DBS). Methods: The study included 53 consecutive patients with DRE who were considered for either VNS or ANT-DBS therapy. As part of the preimplantation clinical protocol, all patients underwent neuropsychological evaluation. Cognitive tests were categorized into four domains: (1) attention and executive functions (AEFs), (2) memory and learning, (3) language functions, and (4) visual functions. Test performance was compared against established normative data. Results: More than one-third of the patients exhibited cognitive impairment across all four assessed domains. Deficits in AEFs were the most prevalent and severe, affecting 66% of the cohort. These impairments were especially pronounced in patients treated with topiramate or zonisamide, as well as in those referred for ANT-DBS. Conclusions: The presurgical neuropsychological evaluation of patients with DRE considered for neurostimulation therapy should place particular emphasis on AEFs. This focus provides a critical baseline for follow-up and enables targeted monitoring of cognitive outcomes during neurostimulation treatment.