Cortical tau pathology: a major player in fibre-specific white matter reductions in Alzheimer's disease?

We read with great interest the article ‘Fibre-specific white matter reductions in Alzheimer’s disease and mild cognitive impairment’ recently published by Mito and colleagues (2018). Using the novel technique of fixed-based analysis (FBA) this cross-sectional study confirmed previous findings from in vivo diffusion weighted imaging (DWI)/diffusion tensor imaging (DTI) that indicate degeneration in specific fibre pathways functionally implicated in Alzheimer’s disease, as well as new data revealing axonal reduction within the posterior cingulum in patients with mild cognitive impairment (MCI). One of the main aims of the study was to determine a potential association of amyloid-β accumulation with white matter degeneration by comparing measures of white matter tract degeneration between MCI patients with a positive amyloid-β PET scan (11C-PiB), i.e. likely representing prodromal Alzheimer’s disease dementia, and those with a negative amyloid-β PET scan.