Concordance and discordance between brain perfusion and atrophy in frontotemporal dementia

The aim of this study was to determine if a dissociation between reduced cerebral perfusion and gray matter (GM) atrophy exists in frontotemporal dementia (FTD). The study included 28 patients with FTD and 29 cognitive normal (CN) subjects. All subjects had MRI at 1.5 T, including T1-weighted structural and arterial spin labeling (ASL) perfusion imaging. Non-parametric concordance/discordance tests revealed that GM atrophy without hypoperfusion occurs in the premotor cortex in FTD whereas concordant GM atrophy and hypoperfusion changes are found in the right prefrontal cortex and bilateral medial frontal lobe. The results suggest that damage of brain function in FTD, assessed by ASL perfusion, can vary regionally despite widespread atrophy. Detection of discordance between brain perfusion and structure in FTD might aid diagnosis and staging of the disease.