Structural network alterations and neurological dysfunction in cerebral amyloid angiopathy

Area of Science:

• Neurology
• Neuroimaging
• Small Vessel Disease Research

Background:

• Cerebral amyloid angiopathy (CAA) is a common small vessel disease and a risk factor for cognitive impairment.
• The mechanisms connecting small vessel disease to cognitive decline are not fully understood.
• Disruption of brain connectivity may link CAA-related lesions to cognitive impairment.

Purpose of the Study:

• To compare structural brain networks in patients with probable CAA and healthy controls.
• To examine the relationship between CAA markers, network efficiency, and clinical outcomes.
• To investigate if reduced network efficiency mediates cognitive impairment in CAA.

Main Methods:

• Structural brain networks were reconstructed using diffusion-weighted MRI in 38 non-demented probable CAA patients and 29 controls.
• Brain network efficiency was analyzed using graph theory.
• Brain amyloid deposition was quantified using Pittsburgh Compound B PET imaging.

Main Results:

• Global brain network efficiency was significantly reduced in CAA patients compared to controls.
• Network disturbances were most prominent in occipital, parietal, and posterior temporal lobes.
• Lower network efficiency correlated with higher cortical amyloid load, increased white matter hyperintensities, lower total brain volume, and microbleeds.

Conclusions:

• Reduced structural brain network efficiency may mediate the relationship between CAA and neurological dysfunction.
• Network efficiency measures could serve as outcome markers for tracking CAA progression.
• Findings highlight the role of disrupted brain connectivity in CAA-related cognitive impairment.