Can Subjective Memory Complaints Identify Aß Positive and Aß Negative Amnestic Mild Cognitive Impairment Patients?

BACKGROUND: The use of biomarkers, in particular amyloid-ß (Aß) changes, has allowed the possibility to identify patients with subjective memory complaints (SMCs) and amnestic mild cognitive impairment (aMCI) who suffer from Alzheimer's disease (AD). Since it is unfeasible that all patients with aMCI could presently undergo biomarkers assessment, it would be important that SMCs might contribute to identify the aMCI patients who have AD amyloid pathology. OBJECTIVES: To know whether aMCI patients with amyloid biomarkers (Aß+) present greater SMCs as compared to those without amyloid biomarkers (Aß-). METHODS: Participants were selected from a cohort of nondemented patients with cognitive complaints and a comprehensive neuropsychological evaluation, on the basis of 1) diagnosis of aMCI; 2) detailed assessment of memory difficulties with the SMC Scale; and 3) known amyloid status. The amyloid status was determined on the basis of either CSF Aß1-42 concentration or amyloid PET imaging. RESULTS: Of the 176 patients with aMCI studied, 90 were Aß+ and 86 were Aß-. The two groups did not differ in terms of age, gender, and education. The SMC total score was not significantly different in the Aß+ aMCI patients (9.48±4.18) when compared to the Aß- aMCI patients (10.52±4.57). The Aß+ aMCI patients had lower scores on the MMSE and memory/learning tests, but not on the Geriatric Depression Scale, when comparing to the Aß- aMCI patients. CONCLUSIONS: Evaluating SMCs does not seem helpful to identify, among patients with aMCI, those who have AD.