The Memory Binding Test Detects Early Subtle Episodic Memory Decline in Preclinical Alzheimer's Disease: A...

Area of Science:

• Neuroscience
• Cognitive Psychology
• Gerontology

Background:

• The asymptomatic phase of Alzheimer's disease (AD) presents an optimal window for identifying clinically meaningful endpoints.
• Early detection of subtle cognitive changes is crucial for timely intervention in neurodegenerative diseases.

Purpose of the Study:

• To evaluate the Memory Binding Test (MBT) for its ability to anticipate emergent subtle episodic memory (EM) deficits in an at-risk phase.
• To compare the sensitivity of the MBT against the Free and Cued Selective Reminding Test (FCSRT) in detecting early signs of AD-related memory decline.

Main Methods:

• A longitudinal study followed 45 individuals over five years, categorized into three groups: Aβ-/controls, Aβ+/stable, and Aβ+/progressors (preclinical-AD).
• The study administered both the MBT, which includes an associative memory component, and the FCSRT to assess episodic memory performance.
• Scores were analyzed to identify declines in free recall, binding-associated scores, total recall, and intrusions.

Main Results:

• The MBT detected episodic memory decline in preclinical-AD individuals up to 4 years before diagnosis, specifically in delayed free recall.
• Binding-associated memory decline was observed with the MBT one year after the initial free recall decline.
• The FCSRT showed a later onset of episodic memory decline, starting up to 3 years before diagnosis, with more significant declines appearing closer to the diagnosis date.

Conclusions:

• The MBT demonstrates higher sensitivity than the FCSRT in detecting early, subtle episodic memory decline associated with the amnesic hippocampal syndrome characteristic of AD.
• The MBT can serve as a sensitive tool for detecting early EM decline in asymptomatic individuals, while the FCSRT is better for classifying stages of decline.
• These tests have the potential to be complementary diagnostic tools, facilitating the development of therapies to delay cognitive decline in Alzheimer's disease.