From Subjective Cognitive Impairment (PRE-MCI) to Alzheimer's Disease: A Two Year Follow UP Study of 143 Subjects (P2.229)

Objective: Subjective Cognitive Impairment (SCI) characterizes a state of subjective complaint, without objective cognitive deterioration and can predict MCI. Background: Preceding Amnestic Mild Cognitive Impairment (A-MCI), between Normal Cognitive Aging and Early ALZHEIMER’s disease (E-AD), there is a pre-MCI state (SCI) where memory complaint is the unique symptom, many years before A-MCI state. It could represent a pure metacognitive impairment. Methods: We followed during 24 months, a cohort of 143 subjects [16 Normal Controls (NC), 62 SCI, 53 A-MCI and 12 E-AD], by a neuropsychological evaluation [MMSE, ADAS-cog, CDR, GDS, SCD, GDS, RL/RI16, RAVLT], annually during 2 years (V0, V1, V2). MRI hippocampal atrophy scoring and Apo-E4 genotyping, were also performed for each patient. Results: At V0 there was a significant difference between SCHELTENS 0 and SCHELTENS II-III groups, for SCD and Total Recall (TR) RL/RI16 scores. Upon 143 patients at V0, 143 reached V1 (13 NC, 59 SCI, 51 A-MCI and 20 E-AD), and 80 V2 (63 dropped out). Upon 62 SCI, 10 developped a A-MCI (16.12[percnt]), and 1 an E-AD (1.61[percnt]) at V1. So we can consider that 11 SCI (17.74[percnt]) were in evolution (SCI-E) and 48 stable (SCI-S). The comparison between SCI-E and SCI-S shows significant differences in RAVLT [total recall TR (p=0.001), delayed recall DR (p=0.0001)] and ApoE4 genotype (p=0.0001). Conclusions: This study suggests that SCI is an intermediate state between NC and A-MCI that can be recognized by careful neuropsychological, MRI and Apo-E status evaluation. Annually follow-up permit to observe the evolution of SCI-E to A-MCI. SCI-E can be detected early at V0 by episodic memory examination (RAVLT TR and DR), ApoE-4 status and MRI SCHELTENS scores. Metacognition impairment in SCI is probably the expression of an anterior prefrontal cortex (PFC) dysfunction, responsible of a hyper-attentional syndrome, corresponding to a degenerative process of white matter anterior cingulum fibers. Disclosure: Dr. Michel has nothing to disclose. Dr. Sambuchi has nothing to disclose. Dr. Geda has nothing to disclose. Dr. Muraccioli has nothing to disclose. Dr. Ronald Petersen received personal compensation from Pfizer, Inc., Janssen Alzheimer9s Immunotherapy. Merck, inc. Roche, Inc. Genentech, Inc. Biogen, Inc. Eli Lilly and Co. as a consultant or speaker.