Longitudinal gray matter atrophy and accompanied functional connectivity alterations in patients with pontine infarction.

Objectives: To investigate the longitudinal changes in gray matter volume (GMV) and functional connectivity (FC) in patients with pontine infarction (PI) during a 6-month follow-up period.

Methods: Twenty-two patients underwent MRI scans and behavioral assessments at 1 week, 1 month, 3 months, and 6 months after PI. Twenty-two normal controls (NC) were administered once with a similar examination. Voxel-wise GMV analysis was used to investigate the difference between the 1 week of PI and NC groups. Longitudinal changes in GMV were assessed and then used as seed regions to explore the accompanying FC changes during the 6-month follow-up. Correlations of the behavioral scores with the imaging indices of clusters with altered GMV and FC were also investigated.

Results: The LPI group exhibited GMV atrophy in the left cerebellar Crus II, right cerebellar lobule VI, right Vermis VI, while the RPI group showed GMV atrophy in the left cerebellar Crus II. The significant decrease of GMV firstly appeared at 1 month and gradually decreased over time. When using brain regions with GMV atrophy as seeds, longitudinal analysis of FC showed a significant decrease between the left cerebellar Crus II and left middle frontal gyrus at 6 months in the LPI group. Furthermore, the longitudinally altered FC values were negatively correlated with motor scores over time.

Conclusion: These findings provide evidence for progressive GMV atrophy in the cerebellum and impaired relative FC in patients with PI, which could provide vital information for investigating neural bases of behavioral recovery in PI.