Cerebral blood flow-single-photon emission computed tomography and Brodmann mapping may facilitate the evaluation of clinical features of early-onset Alzheimer’s disease

A relatively large numbers of studies have reported on the clinical features, classifications, and impairment of cerebral blood flow (CBF) in cases with Alzheimer’s disease. However, only few reports have investigated the relationships between clinical tests and lesion areas in the brain with significantly reduced CBF, assessed using single-photon emission computed tomography (SPECT). This study aimed to assess the correlations between impaired Mini-Mental State Examination (MMSE) scores and reduced CBF using Brodmann area mapping and classify early-onset Alzheimer’s disease (EOAD). Thirty-one patients aged <65 years, with memory impairment, were examined using CBF-SPECT, and MMSE during the same period. Twenty patients were diagnosed with EOAD. We divided the patients into two groups: one with bilateral reduction of CBF in temporo-parietal region and the other with unilateral reduction. The bilateral group had significantly lower MMSE scores than the unilateral reduction group, but it had significantly less family history, significantly poor prognoses, and ten significantly reduced CBF in the Brodmann area (BA) with SPECT. In the bilateral group, there were large correlations between impaired MMSE and reduced CBF regions in the BA. These findings confirm that the classification of EOAD may pave the way to understand patients with EOAD.