Although there are no published reports on such associations, a few studies have found a link between higher CSF or plasma levels of NfL with cortical hypometabolism in AD.66,67 Further, another study has reported longitudinal associations between higher concentrations of NfL and decline in several neuroimaging measures including FDG-PET.68 Collectively, our findings suggest that CBF alterations in the AD spectrum are elicited by the spread of tau tangles, synaptic dysfunction and axonal degeneration. Here, NEFL is linked to Alzheimer disease.