Journal Article

Whole-body muscle MRI of patients with MATR3-associated distal myopathy reveals a distinct pattern of muscular involvement and highlights the value of whole-body examination

Müller, Tobias, Kraya, Torsten, Stoevesandt, Dietrich, Koester, Felicitas, Mensch, Alexander, Zierz, Stephan

2020

Overview

Objective MATR3-associated distal myopathy is a rare distal myopathy predominantly affecting lower legs as well as wrist- and finger extensors. Whilst most distal myopathies are clinically and genetically well characterized, diagnosis often remains challenging. Pattern-based magnetic resonance imaging (MRI) approaches offer valuable additional information. However, a consistent pattern of muscular affection is missing for most distal myopathies. Thus, the aim of the present study was to establish a disease-specific pattern of muscular involvement in MATR3-associated distal myopathy using whole-body MRI. Methods 15 patients (25–79 years of age, 7 female) with MATR3-associated distal myopathy were subjected to whole-body MRI. The grade of fatty involution for individual muscles was determined using Fischer-Grading. Results were compared to established MRI-patterns of other distal myopathies. Results There was a predominant affection of the distal lower extremities. Lower legs showed a severe fatty infiltration, prominently affecting gastrocnemius and soleus muscle. In thighs, a preferential involvement of semimembranous and biceps femoris muscle was observed. Severe affection of gluteus minimus muscle as well as axial musculature, mainly affecting the thoracic segments, was seen. A sufficient discrimination to other forms of distal myopathy based solely on MRI-findings of the lower extremities was not possible. However, the inclusion of additional body parts seemed to yield specificity. Interpretation Muscle MRI of patients with MATR3-associated distal myopathy revealed a distinct pattern of muscular involvement. The usage of whole-body muscle MRI provided valuable additional findings as compared to regular MRI of the lower extremities to improve distinction from other disease entities.

• Publisher: Springer Berlin Heidelberg,Springer Nature B.V
• Subject: Child / Distal Myopathies - diagnostic imaging / Distal Myopathies - genetics / Female / Human Body / Humans / Leg / Magnetic Resonance Imaging / Medicine / Medicine & Public Health / Muscle, Skeletal - diagnostic imaging / Muscles / Muscular Diseases - diagnostic imaging / Myopathy / Neurology / Neuroradiology / Neurosciences / Nuclear Matrix-Associated Proteins / Original Communication / RNA-Binding Proteins / Soleus muscle / Thorax / Wrist