Exploring predementia: Understanding the characteristics of subjective cognitive decline plus from India

Abstract

Background: Subjective cognitive decline (SCD) is the early predementia syndrome. that occurs even before the development of objective cognitive decline. SCD plus refers to an additional set of criteria that increases the likelihood of developing mild cognitive impairment and further progressing to Alzheimer's disease (AD). Studying the progression of SCD-plus participants will help in understanding the importance of diagnosing this condition at an early stage and delaying its onset.

Objective: The present tries to examine neurocognitive changes in individuals who met the criteria of SCD-plus patients. The study also investigated the imaging correlates of these individuals in both cohorts.

Methods: This study included 94 participants from Srinivaspura Aging, Neuro Senescence, and COGnition (SANSCOG) and Tata Longitudinal Study of Aging (TLSA) cohorts who satisfy the criteria of SCD plus. Mann-Whitney U test was used to compare the SCD plus participants and healthy controls. Regression analysis was performed to find the association between SCD plus and cognition.

Results: The SCD-plus group performed poorer than the healthy group in episodic memory delayed recall (p = 0.049), name face recognition (p = 0.023), and letter fluency (p = 0.004) tasks. The generalized linear model revealed that the SCD-plus group had lower left cerebellar cortex (p = 0.010) and right inferior occipital cortex (p = 0.016) volumes than the healthy control group.

Conclusions: The participants in the SCD-plus group performed poorly on memory and language-related tasks, and the volumes of the associated brain regions decreased. This study suggested that the SCD-plus group had characteristics similar to AD group and can help in identifying AD at the earliest.

Keywords: Alzheimer's disease; aging; cognition; imaging; subjective cognitive decline.