Cognitive Impairment Characteristics And Brain Structure And Functional Network In Myotonic Dystrophy Type 1

Background and Objective: Cognitive impairment in Myotonic dystrophy type 1(DM1)has significant effects on the quality of life and social function of patients.There are few studies on DM1 cognitive function and brain structure and functional network in China.This thesis aims to improve the understanding of the characteristics of cognitive impairment and brain structure and functional network of DM1 by studying the cognitive impairment and brain structure and functional network of DM1.Methods: Twelve patients with DM1 diagnosed by genetic testing in Sichuan Provincial People’s Hospital from May 2020 to February 2023 were selected as the study subjects and 10 healthy people as the control group.(1)Clinical manifestations and CTG repeats of pathogenic gene were collected;(2)A complete set of neuropsychological scales to evaluate the patients’ executive ability,visuospatial ability,attention,language function,memory and other cognitive fields.(3)Changes in connections between the Default Mode Network(DMN)and the Task Positive Network(TPN)were evaluated by resting state functional magnetic resonance imaging,and fractional anisotropy(FA)of the white matter was evaluated by Diffusion tensor imaging(DTI).(4)To investigate the correlation between cognitive impairment and white matter microstructure in DM1 patients.Results: Multiple scale evaluations showed that the cognitive function scores of DM1 group were significantly different from those of healthy control group(P < 0.05),and the impaired attention was the most prominent.MoCA scores were decreased in all 12 DM1 patients,and MMSE scores were decreased in 9 of them.There was a significant correlation between the scores of cognitive function scale and functional activity questionnaire(P < 0.05).Compared with the healthy control group,the network connection between DMN and TPN in the DM1 group was abnormally enhanced and weakened.DTI in DM1 patients showed a symmetrical decrease in FA in some white matter tracts.The results of correlation analysis between cognitive function scale and DTI showed that cognitive impairment was significantly correlated with the changes of white matter microstructure.Executive dysfunction was associated with the damage of posterior thalamic radiation,corpus callosum pressure,radiative crown and forelimb of internal capsule.The impairment of visual spatial ability was related to the damage of knee of corpus callosum and radial crown.Attention disorder was associated with damage of corpus callosum,coronal radiata and superior longitudinal tract.The impairment of naming ability was associated with the damage of the radiolone,the posterior limb of the internal capsule and the upper longitudinal tract.Conclusion: DM1 is impaired in several cognitive domains,most notably in attention.DM1 cognitive impairment is more easily detected by MoCA than MMSE.Cognitive impairment has a significant impact on functional activity.The changes of DMN-TPN connection in different patients with DM1 were heterogeneous.Cognitive impairment in different domains of DM1 was associated with changes in white matter microstructural in different regions.