Neurophysiological Mechanisms of Cognitive Resilience in Elderly Adults Exposed to Chronic Environmental Lead in Zamfara State, North West Nigeria: A Longitudinal Electrophysiological and Neuroimaging Study

Background: The Zamfara State artisanal gold mining crisis has produced one of the world's most severe paediatric lead poisoning epidemics. Older adults in these communities face chronic low-to-moderate lead exposure through environmental pathways, yet the neurophysiological basis of differential cognitive resilience in this population has never been investigated. Understanding why some individuals maintain cognitive function despite comparable lead burden may reveal endogenous neuroprotective mechanisms. Objectives: This study aims to identify neurophysiological correlates of cognitive resilience in elderly residents of Zamfara with elevated blood lead levels using a longitudinal design incorporating electroencephalographic event-related potentials, structural magnetic resonance imaging, and a comprehensive neuropsychological battery, while simultaneously profiling genetic and biochemical resilience mediators. Methods: One hundred adults aged 60 and above with confirmed lead exposure will be stratified into cognitively resilient and cognitively impaired groups using composite neuropsychological scores at baseline and two-year follow-up. Resting and task-evoked electroencephalography will characterise neural oscillatory dynamics. Brain morphometry from structural magnetic resonance imaging will assess grey matter volume. Genome-wide methylation profiling will identify epigenetic resilience signatures. Linear mixed models will account for longitudinal data structure. Expected Outcomes: Cognitively resilient individuals are hypothesised to exhibit preserved frontal theta coherence, greater hippocampal grey matter volume, and differential methylation of neuroinflammatory gene loci despite equivalent lead burden. Conclusion: Findings will generate an original theoretical framework for lead-induced neurodegeneration and resilience with global translational relevance. Keywords: cognitive resilience, lead neurotoxicity, electroencephalography, epigenetics, Zamfara.