Longitudinal Multimodal Magnetic Resonance Imaging Reveals Improvement in Verbal Fluency Over Time in...

Area of Science:

• Neuroscience
• Radiology
• Speech Pathology

Background:

• Moderate-to-severe diffuse axonal injury (DAI) often impairs verbal fluency (VF).
• The relationship between brain structural changes and VF recovery post-DAI is not well understood.
• Understanding these links is crucial for predicting and aiding recovery.

Purpose of the Study:

• To assess changes in cortical thickness, white matter integrity (FA, FW), and VF.
• To determine if early brain changes (3-6 months post-DAI) predict later VF performance (6-12 months post-DAI).
• To investigate the role of brain plasticity in VF recovery after DAI.

Main Methods:

• Structural and diffusion MRI data analyzed in 21 adults with moderate-to-severe DAI at 3 and 6 months post-injury.
• Cortical thickness, fractional anisotropy (FA), and free water (FW) in language-related tracts were measured.
• Phonemic and semantic VF scores were assessed at 6 and 12 months post-DAI.

Main Results:

• Cortical thickness increased in several regions bilaterally; FA increased in the right arcuate and inferior longitudinal fasciculi.
• Phonemic VF scores improved between 6 and 12 months post-DAI, but semantic VF did not.
• Early cortical thickness changes in specific frontal and temporal regions predicted improved phonemic VF.

Conclusions:

• Brain plasticity, indicated by increased cortical thickness and white matter integrity, is significant in the first year post-DAI.
• Improved VF is linked to increased thickness in speech-related cortical motor areas.
• Larger studies are needed to confirm these findings on brain changes and verbal fluency recovery.