Cognitive reserve in young-onset cognitive impairment

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neurology

Background:

• Cognitive reserve (CR) is the brain's ability to withstand neuropathology and maintain function.
• Young-onset cognitive impairment (<65 years) presents unique challenges in understanding resilience factors.
• The interplay between CR, brain integrity, and neurodegeneration in early cognitive decline requires further investigation.

Purpose of the Study:

• To investigate the role of cognitive reserve in young-onset cognitive impairment.
• To determine if CR contributes to cognitive function independently of brain integrity and neurodegeneration.
• To explore the differential impact of CR components (education, leisure) on specific cognitive domains.

Main Methods:

• Neuropsychological assessments including the Cognitive Reserve Index questionnaire (CRIq).
• Magnetic resonance imaging (MRI) for brain integrity assessment.
• Blood neurofilaments light-chain (NfLs) measurement as a marker of neurodegeneration.
• Principal Component Analyses (PCA) for deriving cognitive scores.
• Linear regression models to assess predictors of cognitive function.

Main Results:

• Global cognition was significantly explained by CR (ES=0.229), grey matter volume (ES=0.348), and NfLs (ES=-0.302).
• CR demonstrated a prominent effect on language and attentional-executive functions.
• Education-related CR subscore predicted performance in language and executive domains; leisure-related CR subscore predicted language performance.

Conclusions:

• Cognitive reserve plays a significant protective role in young-onset cognitive impairment, particularly for non-amnestic domains.
• High CR can mask or delay the diagnosis of cognitive disorders.
• Incorporating CR measures, including leisure activity engagement, is crucial for accurate neuropsychological test interpretation in early cognitive decline.