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PubMed · 42546587

Cognitive-metabolic relationship in temporal lobe epilepsy: A systematic review.

Mathias Maisenbacher·Ola Alshaqi·Xiaohan Peng·Cindy Schmidt·Mariano Uberti·Vaishali Phatak·Olga Taraschenko
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Abstract

OBJECTIVE: To summarize the current literature on neurometabolic dysfunction identified through brain imaging and its cognitive correlates in temporal lobe epilepsy (TLE). BACKGROUND: Cognitive decline contributes to chronic disability in TLE. The pathophysiology of cognitive decline in TLE is poorly understood, limiting therapeutic advances. Characterizing metabolic changes in patients with TLE and cognitive impairment may identify biomarkers and inform new treatment strategies. DESIGN/METHODS: We conducted a systematic review of five major databases, gathering studies published through December 2024, in accordance with PRISMA guidelines. We included all observational studies describing associations between metabolic imaging findings and cognitive measures in TLE. RESULTS: Of 1449 reports, 38 met the inclusion criteria, encompassing 1161 patients with TLE aged 5-66 years. Twenty-two studies applied fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) to assess interictal brain glucose metabolism. Two studies utilized PET with other tracers to assess more specific metabolic aspects. Fourteen studies used proton magnetic resonance spectroscopy (1H-MRS) to quantify local concentrations of brain metabolites. Impairment of verbal memory was consistently associated with left temporal lobe metabolite changes. Non-memory cognitive impairments correlated with changes in glucose metabolism, N-acetylaspartate, and gamma-aminobutyrate in both temporal and extratemporal areas. CONCLUSION: 18F-FDG PET remains the most widely used imaging modality to assess cognitive-metabolic correlates in TLE, while other PET tracers and 1H-MRS are potentially underexplored. Verbal memory impairment correlates robustly with left temporal dysmetabolism. Cognitive impairment in TLE is multifaceted and correlates with measurable changes in metabolism in both temporal and extratemporal regions. While our synthesis was restricted by some methodological limitations, these neurometabolic signatures may hold promise as potential biomarkers for identifying risk of cognitive decline and highlight avenues for future research.

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HumansEpilepsy, Temporal LobePositron-Emission TomographyCognitive DysfunctionBrainFluorodeoxyglucose F18CognitionMagnetoencephalographyMemory impairmentPositron emission tomographyTemporal lobe epilepsyJournal ArticleSystematic ReviewReview

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Mathias Maisenbacher, Ola Alshaqi, Xiaohan Peng, Cindy Schmidt, Mariano Uberti, Vaishali Phatak, Olga Taraschenko. 2026-08-03. Cognitive-metabolic relationship in temporal lobe epilepsy: A systematic review.. https://doi.org/10.1016/j.yebeh.2026.111224

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Brain subjectCognition subjectCognitive Dysfunction subjectEpilepsy, Temporal Lobe subjectHumans subjectJournal Article subjectJournal Article; Systematic Review; Review resourceSystematic reviews study

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