Frontotemporal Dementia on Brain Perfusion SPECT

Brain perfusion SPECT in a patient with progressive personality changes, disinhibition, and executive dysfunction (but relatively preserved memory early in the disease) shows bilateral FRONTAL and ANTERIOR TEMPORAL hypoperfusion with relative sparing of parietal cortex. This pattern is most consistent with:

1. AFrontotemporal dementia (FTD) — the classic anterior-predominant hypoperfusion pattern
2. BAlzheimer's disease — typically causing bilateral posterior parietal and temporoparietal hypoperfusion with relative preservation of frontal and primary sensorimotor cortices until advanced stages
3. CVascular dementia — characterized by asymmetric, multifocal cortical and subcortical hypoperfusion in a vascular territory distribution reflecting cumulative ischemic white matter injury
4. DLewy body dementia — producing posterior occipital hypoperfusion with relative cingulate cortex sparing (the cingulate island sign), accompanied by reduced dopaminergic striatal tracer binding on DaTscan