Alterations in degree centrality and functional connectivity associated with cognitive Impairment in myotonic...

The study aimed to examine alterations in voxel-based degree centrality (DC) and functional connectivity (FC), and their relationship with cognitive impairments in patients with myotonic dystrophy type 1 (DM1).

Eighteen DM1 patients and eighteen healthy controls participated in the study and were assessed using a comprehensive neuropsychological battery. Voxel-wise DC and FC analyses were used to assess abnormalities in functional connections among aberrant hubs. Correlational analyses were used to identify and explore the relationship between DC and FC values and cognitive performance in DM1 patients.

DM1 patients exhibited reduced DC in the bilateral Rolandic operculum, left inferior frontal gyrus (triangular part), right angular gyrus, right median cingulate and paracingulate gyri, and right middle temporal gyrus. Conversely, increased DC was observed in the right fusiform gyrus, right hippocampus and left inferior temporal gyrus. FC analysis revealed that altered connectivity predominantly occurred among the right middle temporal gyrus, right angular gyrus and left inferior frontal gyrus (triangular part). DC value in left inferior temporal gyrus showed significant correlations with scores from the Digital Span Test-Forward (r = -0.556, p = 0.025), the Digital Span Test -Backward (r = -0.588, p = 0.017), the Auditory Verbal Learning Test (r = -0.586, p = 0.017) and the Rey-Osterrieth Complex Figure test (copying version) (r = 0.536, p = 0.032) in DM1 patients. No significant correlations were discovered between FC values and neurocognitive performances.

The study demonstrated that abnormalities in DC and FC may become potential neuroimaging biomarkers for cognitive decline in DM1 patients.