Brain axonal and myelin evaluation in heart failure

Area of Science:

• Neuroimaging
• Cardiovascular Disease
• Neuropathology

Background:

• Heart failure (HF) is associated with gray matter injury, but axonal injury's impact on cardiovascular regulation remains unclear.
• Understanding neural alterations in HF is crucial for addressing associated autonomic and neuropsychological symptoms.

Purpose of the Study:

• To investigate the presence, extent, and nature of axonal and myelin injury in the brains of heart failure patients.
• To correlate observed neural changes with cardiovascular regulation and other functional impairments.

Main Methods:

• Diffusion tensor imaging (3.0-Tesla MRI) was used to assess whole-brain water diffusion in 16 HF patients and 26 controls.
• Axial diffusivity (axonal integrity) and radial diffusivity (myelin changes) were analyzed in various brain regions.

Main Results:

• Impaired axonal integrity (increased axial diffusivity) was found in cardiovascular, hedonic, and pain regulatory areas.
• Myelin breakdown (increased radial diffusivity) was observed in the corpus callosum and cortical regions.
• Global tissue integrity loss (both diffusivities) occurred in parietal/occipital lobes, insula, and cerebellum.

Conclusions:

• Heart failure is associated with significant axonal and myelin alterations in the brain.
• These neural changes are likely due to chronic ischemic/hypoxic processes.
• The observed brain alterations may explain the diverse autonomic and neuropsychological symptoms in HF patients.