Lower limb muscle magnetic resonance imaging in Chinese patients with myotonic dystrophy type 1

ABSTRACT

Objectives: Muscle magnetic resonance imaging (MRI) is a reliable noninvasion tool for detecting muscle abnormalities of myopathies. This study aimed to investigate the MRI features of lower limb muscles in Chinese patients with myotonic dystrophy type 1 (DM1) and to evaluate the correlation between clinical factors and muscle MRI.

Methods: We retrospectively reviewed the medical records and lower limb muscle MRI in 24 Chinese DM1 patients. Muscular Impairment Rating Scale (MIRS) was used to assess the clinical muscular impairment. Modified Mercuri’s scale was used to assess the degree of fatty infiltration. Spearman rank correlation test was used to analyze the relationship between fatty degeneration score with age, age of onset, disease duration, MIRS grading and creatinine kinase (CK) level.

Results: Fatty infiltration was found in 22 of 24 DM1 patients and 8 patients were asymmetrically affected. The medial gastrocnemius was the most affected muscle, followed by soleus and tibialis anterior muscles in lower legs. At thigh level, the anterior compartment was usually the most affected region with the rectus femoris relatively spared. 79.2% of DM1 patients had edema in lower limb muscles. The total mean score of fatty infiltration correlated with MIRS grading, age and disease duration but did not correlate with the age of onset or CK level.

Conclusion: Here, we found fatty infiltration present in most Chinese DM1 patients with a selective involvement pattern. There is a correlation between the total mean score of fatty infiltration and MIRS grading, age and disease duration.

KEYWORDS:

• Lower limb muscle
• magnetic resonance imaging
• chinese patients
• myotonic dystrophy type 1
• muscular Impairment Rating Scale

Acknowledgments

We strongly acknowledge and appreciate the participation and cooperation of the patients and their families.

Authors’ contributions

JS: data collection and analysis, image analysis, manuscript preparation. JF: data collection and analysis, statistical evaluation, reviewing of manuscript. MMM: data collection, reviewing of manuscript. MP: data collection and analysis. GL: data analysis. LG: image analysis. JWZ: study design, reviewing of manuscript, approval of manuscript.

Availability of data and materials

The data used in this study are available from the corresponding author on reasonable request.

Disclosure statement

No potential conflict of interest was reported by the authors.

Ethics approval and consent to participate

The principles of the Declaration of Helsinki were followed and this study was approved by the ethics committee of the Henan Provincial People’s Hospital (approval number: 201821001). Written informed consents were obtained from all participants.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (81100881).

Notes on contributors

Jia Song

Jia Song is an attending physician in the Department of Neurology, Henan Provincial People’s Hospital with a master degree graduated from the Sun Yat-Sen University.

Jun Fu

Jun Fu is a postdoctoral fellow in the Department of Neurology, Henan Provincial People’s Hospital with a Ph.D. in the Peking University.

Mingming Ma

Mingming Ma is an associate chief physician and the director of neuromyopathy subspecialty, Henan Provincial People’s Hospital. He got Ph.D. in Neurology from Xiangya Hospital Central South University and was to be postdoctoral fellow NDSU in the United States.

Mi Pang

Mi Pang is an attending physician in the Department of Neurology, Henan Provincial People’s Hospital with a master degree in the Capital Medical University.

Gang Li

Gang Li is an associate chief physician in Henan Provincial People’s Hospital with a master degree in neurology from Xiangya Hospital Central South University.

Li Gao

Li Gao is an attending physician in the imaging department, Henan Provincial People’s Hospital with a master degree in the Huazhong University of Sciences and Technology.

Jiewen Zhang

Jiewen Zhang is a professor in the People’s Hospital of Zhengzhou University with a doctor degree of medicine. He is also the director of the department of neurology in Henan Provincial People’s Hospital and to be Ph.D. supervisor.