Striatal Dopaminergic Depletion Pattern Reflects Pathological Brain Perfusion Changes in Lewy Body Diseases

<jats:title>Abstract</jats:title><jats:sec> <jats:title>Purpose</jats:title> <jats:p>In Lewy body diseases (LBD), various symptoms occur depending on the distribution of Lewy body in the brain, and the findings of brain perfusion and dopamine transporter single-photon emission computed tomography (DAT-SPECT) also change accordingly. We aimed to evaluate the correlation between brain perfusion SPECT and quantitative indices calculated from DAT-SPECT in patients with LBD.</jats:p> </jats:sec><jats:sec> <jats:title>Procedures</jats:title> <jats:p>We retrospectively enrolled 35 patients with LBD who underwent brain perfusion SPECT with N-isopropyl-p-[<jats:sup>123</jats:sup>I] iodoamphetamine and DAT-SPECT with <jats:sup>123</jats:sup>I-ioflupane. Mini-mental state examination (MMSE) data were also collected from 19 patients. Quantitative indices (specific binding ratio [SBR], putamen-to-caudate ratio [PCR], and caudate-to-putamen ratio [CPR]) were calculated using DAT-SPECT. These data were analysed by the statistical parametric mapping procedure.</jats:p> </jats:sec><jats:sec> <jats:title>Results</jats:title> <jats:p>In patients with LBD, decreased PCR index correlated with hypoperfusion in the brainstem (medulla oblongata and midbrain) (uncorrected <jats:italic>p</jats:italic> < 0.001, <jats:italic>k</jats:italic> > 100), while decreased CPR index correlated with hypoperfusion in the right temporoparietal cortex (family-wise error corrected <jats:italic>p</jats:italic> < 0.05), right precuneus (uncorrected <jats:italic>p</jats:italic> < 0.001, <jats:italic>k</jats:italic> > 100), and bilateral temporal cortex (uncorrected <jats:italic>p</jats:italic> < 0.001, <jats:italic>k</jats:italic> > 100). However, there was no significant correlation between decreased SBR index and brain perfusion. Additionally, the MMSE score was correlated with hypoperfusion in the left temporoparietal cortex (uncorrected <jats:italic>p</jats:italic> < 0.001).</jats:p> </jats:sec><jats:sec> <jats:title>Conclusions</jats:title> <jats:p>This study suggests that regional changes in striatal <jats:sup>123</jats:sup>I-ioflupane accumulation on DAT-SPECT are related to brain perfusion changes in patients with LBD.</jats:p> </jats:sec>