Functional Connectivity Density with Frequency-Dependent Changes in Patients with Diffuse Axonal Injury: A...

Area of Science:

• Neuroscience
• Medical Imaging
• Neurology

Background:

• Diffuse axonal injury (DAI) is a common traumatic brain injury characterized by widespread axonal damage.
• Understanding the functional consequences of DAI is crucial for diagnosis and treatment.
• Spontaneous brain connectivity alterations are increasingly recognized as a key feature of DAI.

Purpose of the Study:

• To investigate changes in spontaneous brain connectivity in patients with DAI.
• To assess these changes using functional connectivity density (FCD) across different frequency bands.
• To explore the relationship between altered brain connectivity and clinical indicators of DAI severity.

Main Methods:

• 23 DAI patients and 23 healthy controls (HCs) underwent resting-state functional magnetic resonance imaging (fMRI).
• Functional connectivity density (FCD) was measured in three frequency bands: slow-4 (0.027-0.073 Hz), slow-5 (0.01-0.027 Hz), and typical (0.01-0.08 Hz).
• Pearson's correlation was used to examine the association between FCD values and clinical scores.

Main Results:

• DAI patients showed significantly different FCD values compared to HCs across all tested frequency bands.
• Specific regions, including the cingulate gyrus, hippocampus, precuneus, and temporal/frontal gyri, exhibited altered FCD.
• Abnormal FCD values in these regions demonstrated a linear correlation with various clinical scale scores.

Conclusions:

• DAI is associated with widespread disruptions in the brain's functional network, as evidenced by abnormal FCD.
• The observed connectivity changes are frequency-dependent, suggesting distinct network alterations in different frequency bands.
• These findings provide novel insights into the pathogenesis of functional impairment in DAI and may elucidate underlying neuropathological or compensatory mechanisms.