Combined Impact of Cortical Cerebral Microinfarcts and Brain Atrophy on Cognitive Decline
Overview
This longitudinal study of 475 memory clinic patients demonstrates that cortical cerebral microinfarcts (CMIs) are associated with accelerated brain volume loss over 2 years. Moreover, the presence of CMIs, especially multiple lesions, synergistically exacerbates cognitive decline over 5 years, particularly affecting executive function, memory, language, and visuospatial abilities.
Background
Cortical cerebral microinfarcts are small ischemic lesions in the cerebral cortex linked to cerebral small vessel disease and cognitive dysfunction. They are more prevalent in Alzheimer’s disease and vascular dementia and may contribute to cognitive impairment through local and remote effects on brain structure. Brain atrophy, a common endpoint of neurodegenerative and vascular pathologies, is independently associated with cognitive decline. While cross-sectional studies have linked CMIs to brain atrophy, longitudinal data on their combined impact on cognition are limited.
Data Highlights
Measure
Effect of CMIs at Year 2 (β, 95% CI)
P-interaction with time
Total Brain Volume
−1.94 (−3.07, −0.82)
<0.001
Grey Matter Volume
−1.00 (−1.69, −0.30)
0.002
White Matter Volume
−0.95 (−1.54, −0.35)
<0.001
Global Cognitive Scores at Year 5 (Single Microinfarct)
−1.83 (−2.68, −0.97)
<0.001
Global Cognitive Scores at Year 5 (Multiple Microinfarcts)
−3.13 (−4.21, −2.05)
<0.001
Key Findings
Cortical CMIs are significantly associated with greater decreases in total brain, grey matter, and white matter volumes over 2 years.
Brain volume loss is more pronounced in patients with multiple CMIs compared to those with single or no microinfarcts.
Patients with high brain volume loss and CMIs, especially multiple lesions, show significantly lower global cognitive scores over 5 years.
The synergistic effect of CMIs and brain atrophy is most evident in executive function, memory, language, and visuospatial domains.
Global cognitive trajectories indicate the steepest decline in patients with multiple CMIs combined with high brain volume loss.
Clinical Implications
Clinicians should consider the presence and burden of cortical CMIs when evaluating patients with cognitive impairment, as these lesions contribute to accelerated brain atrophy and cognitive decline. Monitoring brain volume changes alongside microinfarct burden may improve prognostication and guide interventions targeting mixed vascular and neurodegenerative pathologies. Early detection of multiple CMIs could identify patients at higher risk for rapid cognitive deterioration.
Conclusion
This study establishes that cortical cerebral microinfarcts contribute to progressive brain atrophy and synergistically worsen cognitive decline, highlighting the importance of mixed vascular and neurodegenerative pathologies in dementia development. Future research should further explore these interactions to improve diagnosis and treatment strategies.
References
Wang et al. 2023 -- Combined Influence of Cortical Cerebral Microinfarcts and Brain Atrophy on Cognitive Deterioration
