Implementation of amyloid PET in a memory clinic of geriatric hospital revealed characteristics of causative diseases by age

Abstract

AbstractBackgroundClinical impact and significance of amyloid PET on dementia diagnosis in the real‐world memory clinic of gerontology hospital have been evaluated by age group.MethodsWe analyze the data from 340 adult patients (age 72.3 ± 9.9, M/F: 151/189) visited the memory clinic of Tokyo Metropolitan Institute for Geriatrics and Gerontology with progressive cognitive decline and who had PiB‐PET for clinical evaluation. Pre‐PET diagnosis was based on the clinical evaluation with neuropsychological tests, MRI for all the cases and with perfusion SPECT, dopamine transporter SPECT, MIBG cardiac scintigraphy as needed. PiB‐PET was evaluated by visual diagnosis (A+/A‐). FDG‐PET was added for further differentiation. Post‐PET diagnosis was analyzed 3 to 6 months after PiB‐PET in three age groups (age<65, 65‐74, and > = 75). We obtained autopsy diagnosis from 25 cases of them.ResultsWe included 189 females and 151 males (age 72.3 ± 9.9). Pre‐PET diagnosis consisted of 198 AD and 142 non‐AD. 27% of clinically diagnosed AD patients were considered non‐AD by PiB‐PET. 30% of clinically diagnosed non‐AD patients were amyloid positive, one third of them were reconsidered to be AD, however, two‐thirds of them were still regarded as non‐AD (concomitant pathology) especially in the aged patients. Amyloid positivity more strongly suggest AD in younger patients. Younger patients have larger population of non‐pathological background such as depression, adjustment disorder, developmental disorder, etc. Autopsy diagnosis confirmed the accuracy of PiB‐PET diagnosis.ConclusionPiB‐PET provides highly accurate diagnosis of dementia which has age‐related characteristics.