[Structural and functional changes of the hippocampus in patients with multiple sclerosis and their relationship with...

One of the most prevalent cognitive deficits in multiple sclerosis (MS) patients relates to (both verbal and visual) information encoding, a process related the hippocampus.

To assess the relationship between information learning and long-term retention processes and hippocampal volume and functional connectivity (FC) in MS patients.

MS patients and a control group of healthy volunteers were assessed using the brief neuro-psychological battery, which includes tests of verbal and visual memory. Gray matter volume was assessed through the voxel based morphometry technique, and a study of seed-based FC focused on the region of ??interest (hippocampus) was also conducted.

Results revealed that, as compared to the control group, MS patients display gray matter atrophy at the left hippocampus gray matter and smaller FC between left hippocampus and brainstem, cerebellum, fusiform gyrus and superior temporal gyrus. Association analyses were performed between memory tests performance and both volumetric and FC changes. Results showed a positive correlation between gray matter hippocampal (bilateral) volume and verbal memory performance of the MS group. Further, in MS patients, a positive correlation between visual memory performance and FC between the left hippocampus and several temporal regions was also found.

The results of the present study reveal a relationship between structural and functional changes in the hippocampus of MS patients and their performance on verbal and visual memory tests.