Fig. 1.

Flow-chart of the study sample. We first identified 18 outpatients presenting with a possible confabulation-misidentification phenotype (CM-phenotype) among the patients with AD diagnosis supported by positive biomarkers in the CSF visited in a ten-year period at the Geriatric Unit of the Ca’ Granda Foundation hospital. Then, we excluded one CM-AD patient from this group because she was at moderate stage of dementia (CDR: 2) when she came to our first observation. At the same time, we first selected 33 outpatients presenting with a classical amnesic phenotype (CA-phenotype) among the 36 outpatients with AD diagnosis supported by positive biomarkers in CSF remaining in the outpatient registry in the same period after the extraction of the 18 CM-AD patients. Instead, 3 patients were excluded because presenting an atypical phenotype of AD (i.e., corticobasal syndrome, PCA syndrome, logopenic aphasia). Then, we excluded 3 CA-ADs because they were at advanced stage of dementia (all CDR: 2) at the time of the first visit. In total, 17 CM-ADs and 30 CA-ADs, all at early dementia stage (CDR 0.5 or 1), participated in the cross-sectional study at the time of the baseline assessment. Instead, 17 CM-ADs and 29 CA-ADs participated in the longitudinal study, due to the fact that one CA-AD patient underwent follow-up visits into a different hospital. Finally, we selected 40 people taken from the general outpatient registry in the same Unit among those patients resulted cognitively unimpaired after the neuropsychological assessment, who served as healthy controls (HC) group in the first baseline assessment.