Affiliations: [a] Alzheimer’s Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, Barcelona, Spain
| [b] Institut d’ Investigacions Biomèdiques August pi i Sunyer (IDIBAPS), Barcelona, Spain
| [c]
Barcelona Beta Brain Research Center, Pasqual Maragall Foundation, Barcelona, Spain
Correspondence:
[*]
Correspondence to: Dr. José Luis Molinuevo Guix, Alzheimer’s Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, Villarroel 170, 08036 Barcelona, Spain. Tel.: +34 932275785; Fax: +34 932 275783; E-mail: [email protected].
Note: [1] These authors contributed equally to this work.
Abstract: Background:There is a need to specify the profile of subjective cognitive decline in preclinical Alzheimer’s disease (preAD). Objectives:To explore specific items of the Subjective Cognitive Decline Questionnaire (SCD-Q) that discriminate preAD from normal aging. Methods:68 cognitively normal older adults were classified as controls (n = 52) or preAD (n = 16) according to amyloid-β (Aβ) levels. An exploratory factor analysis and item analysis of the SCD-Q were performed. Informant reports of the SCD-Q were used to corroborate the findings of self-reports. One-year neuropsychological follow-up was available. Results:Four SCD-Q factors were extracted: EM-factor (episodic memory), A-factor (attention), O-factor (organization), and L-factor (language). PreAD reported a significantly higher decline in L-factor (F(1) = 6.49; p = 0.014) and A-factor (F(1) = 4.04; p = 0.049) compared to controls, and showed a higher frequency of perceived decline in SCD-Q items related with language and executive tasks (Sig-items.) Significant discriminative powers for Aβ-positivity were found for L-factor (AUC = 0.75; p = 0.003) and A-factor (AUC = 0.74; p = 0.004). Informants in the preAD group confirmed significantly higher scores in L-factor and Sig-items. A significant time×group interaction was found in the Semantic Fluency and Stroop tests, with the preAD group showing a decrease in performance at one-year. Conclusions:Our results suggest that SCD-Q items related with language and executive decline may help in prediction algorithms to detect preAD. Validation in an independent population is needed.
