Is the regional cerebral blood flow always decreased in the occipital lobe of patients with dementia with Lewy bodies? A SRECT easy Z‐score imaging system perfusion study

Abstract

AbstractBackgroundIt is well known that the regional cerebral blood flow (rCBF) is decreased in the occipital lobe in patients with dementia with Lewy bodies (DLB). However, the incidences of decreased rCBF of the occipital lobe are not obvious in DLB patients using the ordinary single‐photon emission computed tomography (SPECT) perfusion study.AimTo analyze rCBF in the occipital lobe in patients with DLB and in those with other diseases with dementia in the retrospective study.MethodsThe rCBF of patients with DLB (16 patients), Parkinson's disease with dementia (PDD) (18), Alzheimer's disease (AD) (75), and mild cognitive impairment (MCI) of amnestic type (14), and of elderly without dementia (normal controls: NCs) (6) was examined using technetium‐99m ethyl cysteinate dimer(99mTc‐ECD) SPECT (easy Z‐score imaging system: eZIS) perfusion study.ResultsFour types of decrease in the rCBF were observed in the occipital lobe of DLB patients: “none” and decreases in the “upper region,” “disseminated areas,” or “visual cortex.” The incidences of decreases in the rCBF in the occipital lobe in DLB patients were compared to AD, indicating a sensitivity of 88% and specificity of 53% when the lesions included any of four types. However, when the decrease was limited only to the “disseminated areas” or “visual cortex” types, the sensitivity was 50% and the specificity 85%.ConclusionThe decrease in the rCBF in the occipital lobe specific to DLB was the “disseminated areas” or “visual cortex” type, which was observed in only 50% of DLB patients.