Mapping the cognitive landscape: a pilot study of domain-specific outcomes following frontal lobe resection in children with epilepsy

TL;DR

This pilot study shows that cognitive outcomes after frontal lobe surgery in children with epilepsy vary widely and are better understood using domain-specific assessments rather than general measures.

Contribution

The study introduces a feasible domain-specific cognitive assessment protocol and identifies novel trends linking clinical variables to postoperative cognitive outcomes.

Findings

Cognitive outcomes were highly variable and domain-specific, not captured by global measures.

Higher preoperative ASM load and lack of postoperative ASM reduction were linked to cognitive declines in specific domains.

Surgical laterality had a pronounced effect, with right-sided resections causing universal visuospatial deficits.

Abstract

Pediatric frontal lobe epilepsy surgery can achieve seizure freedom, but cognitive outcomes are heterogeneous and poorly predicted by global measures. This pilot study aimed to implement a domain-specific cognitive assessment protocol and perform an exploratory analysis to identify clinical variables that may influence postoperative outcomes, thereby generating hypotheses for future research.

This retrospective pilot study included 17 pediatric patients with drug-resistant epilepsy (DRE) who underwent frontal lobe resection. All patients completed the Computerized Cognitive Testing in Epilepsy (CCTE) battery before and at least 6 months after surgery, assessing memory, attention, language, mathematics, reasoning, visuospatial skills, and psychomotor speed. Domain-specific change was calculated. An exploratory analysis examined associations with antiseizure medication (ASM) burden, age at onset, age at surgery, epilepsy duration, and resection side.

Implementation of the protocol was feasible (100% completion). Cognitive outcomes were highly heterogeneous and domain-specific. Exploratory analyses suggested trends warranting future investigation: a higher preoperative ASM load was associated with a decline in numerical reasoning, while a lack of postoperative ASM reduction was linked to declines in associative memory and psychomotor speed. Earlier seizure onset and younger surgical age were observed in patients with visuospatial deficits, whereas older surgical age and longer epilepsy duration were observed in those with language impairments. A paradoxical trend indicated that higher baseline performance in several domains was associated with greater postoperative decline. A pronounced lateralization effect was noted, with visuospatial deficits universal after right-sided resections but not after left-sided resections.

This pilot study demonstrates the feasibility and clinical value of domain-specific cognitive assessment, revealing heterogeneous outcomes not captured by global measures. The exploratory findings generate specific hypotheses regarding the roles of ASM management, developmental timing, baseline cognition, and surgical laterality. These results provide a foundation for larger, prospective studies to build predictive models for personalized postoperative rehabilitation.

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