GFAP and Mental deterioration: As described by the cognitive reserve theory, higher educational levels are believed to extend the time to cognitive decline.37 However, it has been proposed before that the rate of neurodegenerative processes is not influenced by educational levels.38 Instead, it is possible that although patients of higher education would have higher baseline MMSE levels, the rate of cognitive decline would still be comparable with that of patients with lower education and similar baseline plasma NfL or GFAP concentrations.