MAPT and corticobasal syndrome: Investigators thus examined spread of tau from the cerebrum into hypothesized brainstem regions in behavioural variant frontotemporal dementia (bvFTD) and corticobasal syndrome.24 Reasoning that these clinical syndromes would implicate different descending pathways, they found relatively distinct distributions of tau pathology in the corticospinal tract for corticobasal syndrome and in the prefrontopontine pathway in bvFTD.