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Background: Amyloid positron emission tomography (PET) imaging is appropriate for patients with atypical presentation, unusually rapid course and very early onset of dementia. Standardized uptake value ratios (SUVr) are used for relative quantification of 18F‐florbetaben (18F‐FBB) PET scans and cerebellar cortex can be used as reference region for quantification. Previous study showed that 18F‐FBB PET demonstrated a diffuse cortical uptake and in particular an intense uptake in the basal ganglia in familial Alzheimer’s disease with presenilin‐1(PS‐1) mutation. Method: This report describes the case of a young woman with early‐onset familial Alzheimer’s disease(EOfAD), who has atypical pattern of uptake on amyloid PET. Result: A 37‐year‐old woman with a college level educational background was brought in by her family for further evaluation of cognitive impairment, personality and behavioral changes. At age 30 years of age, the patient presented memory impairment and she had difficulty serving guests in bakery. Patient had positive family history of early onset dementia; her father, grand mother, and two sisters of grand mother. (Fig. 1 Pedigree showing autosomal dominant inheritance trait of early‐onset dementia. (nn/nn) Age at onset/age at death). She had an initial Mini‐Mental State Examination score of 22/30 (time disorientation, dyscalculia, poor delayed recall). Neuropsychological assessment showed global cerebral dysfunction and revealed dementia with psychiatric symptoms. Brain magnetic resonance imaging showed no significant abnormality. On genetic testing, homozygotes for the apolipoprotein E ε3 allele and a PS‐1 mutation (c.616G>A , p.G602S) was identified. 18F‐FBB PET revealed diffusely increased amyloid deposition including not only bilateral frontal, parietal, posterior cingulate gyrus/precuneus, anterior striatum but also bilateral cerebellar cortex. (Fig. 2 18F‐florbetaben PET, at age 37) Conclusion: This will be the first case report of EOfAD with increased bilateral cerebellar cortical uptake on 18F‐ FBB PET, we present the case to increase awareness of this unusual entity. [ABSTRACT FROM AUTHOR]

Background: Around 15–20% of patients with clinically probable Alzheimer’s disease have been found to have no significant Alzheimer’s pathology on amyloid PET. A previous study shows that conversion to dementia from amyloid‐negative mild cognitive impairment (MCI) was observed in up to 11% of patients, drawing attention to this condition. We gathered the detailed neuropsychological and neuroimaging data of this population to elucidate factors for conversion to dementia from amyloid‐negative amnestic MCI. Method: This study was a retrospective cohort study of patients over the age 50 with amyloid‐negative amnestic MCI who visited the memory clinic of Asan Medical Center with no less than a 36 months follow‐up period. All subjects underwent detailed neuropsychologic tests, three tesla brain magnetic resonance imaging (MRI) scans including 3‐dimensional T1 imaging, and fluorine‐18[F18]‐florbetaben amyloid PET scans. Result: During the 36 months of follow‐up, 39 of 107 (36.4%) patients converted to dementia from amnestic MCI. The volumetric analysis revealed that the converter group had significantly reduced total hippocampal volume on the right side, gray matter volume in the right lateral temporal, lingual gyri, and occipital pole. In terms of cerebellar gray matter (GM) volumetric analysis, reduced Crus I/II volume adjusted with total intracranial volume (TIV) and age was observed in the converter group. The converter group had also more severe impairments in all visual memory tasks. Conclusion: Our study showed that the reduced gray matter volume related to visual memory processing in the cerebrum and Significant cerebellar GM atrophy involving the bilateral Crus I/II may predict the clinical progression in this amyloid‐negative MCI population. [ABSTRACT FROM AUTHOR]

Background: Pathophysiology of cognitive decline in CAA is multifactorial, because microbleeds, white matter hyperintensities, and combined concomitant parenchymal Alzheimer’s disease (AD) pathology have been suggested to cause cognitive impairment. The mechanism by which microbleeds affect cognitive impairment is still under investigation. We aimed to investigate the mechanism of how microbleeds contribute to cognitive impairment, in association with white matter tract abnormalities or cortical thickness in CAA with significant amyloid deposition. Method: We retrospectively investigated 30 patients with probable CAA according to Boston criteria and 30 patients with Alzheimer’s disease (AD), all of whom showed severe amyloid deposition on amyloid PET (Aβ+). Age, sex, and clinical deteriorating scale were matched. Using MRI, cortical thickness and white matter tract abnormalities as fractional anisotropy (FA) were obtained. We compared cortical thickness, FA, and cognitive scores of five domains between Aβ+ CAA and Aβ+ AD. Using path analysis, we investigated the correlation between number of regional microbleeds, cortical thickness, FA, and cognitive impairments. Result: Both CAA and AD group showed similar cortical amyloid deposition in AD related regions such as precuneus, and posterior cingulate cortex suggesting that CAA in this study might have AD pathology. Patients with Aβ+ CAA presented with significantly lower FA in clusters of posterior area than patients with Aβ+ AD (FWE‐corrected p value <0.05) Importantly, total number of microbleeds were associated with decreased FA in tapetum of corpus callosum (r=‐0.429, p<0.001), which were consequently associated with visuospatial function (r=0.466, p<0.001). Cortical thickness was not significantly different between CAA and AD, and it did not mediate the association between regional microbleeds and cognition. Conclusion: This study suggests that lobar microbleeds may impact cognitive decline through the mediation of white matter tract abnormalities in CAA. [ABSTRACT FROM AUTHOR]