Characteristics of the muscle involvement along the disease progression in a large cohort of oculopharyngodistal myopathy compared to oculopharyngeal muscular dystrophy

• Published in: Journal of neurology Vol. 270; no. 12; pp. 5988 - 5998
• Main Authors: Eura, Nobuyuki, Noguchi, Satoru, Ogasawara, Masashi, Kumutpongpanich, Theerawat, Hayashi, Shinichiro, Nishino, Ichizo
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.12.2023; Springer Nature B.V
• Subjects: Disease Progression; Humans; Medicine; Medicine & Public Health; Muscle, Skeletal - diagnostic imaging; Muscular Diseases - genetics; Muscular dystrophy; Muscular Dystrophy, Oculopharyngeal - genetics; Myopathy; Neurology; Neuroradiology; Neurosciences; Original Communication; Oculopharyngodistal myopathy; Skeletal muscle imaging; Oculopharyngeal muscular dystrophy
• ISSN: 0340-5354; 1432-1459
• DOI: 10.1007/s00415-023-11906-9

Background and objectives Oculopharyngodistal myopathy (OPDM) is an autosomal dominant myopathy clinically characterized by distal muscle weakness. Even though the identification of four causative genes, LRP12 , GIPC1 , NOTCH2NLC and RILPL1 , it is unclear whether the myopathy progressed similarly among OPDM subtypes. We aimed to establish diagnostic clues in muscle imaging of OPDM in comparison with clinicopathologically similar oculopharyngeal muscular dystrophy (OPMD). Methods Axial muscle CT and/or T1-weighted MRI data from 54 genetically confirmed patients with OPDM (OPDM_LRP12; n = 43, OPDM_GIPC1; n = 6, OPDM_NOTCH2NLC; n = 5) and 57 with OPMD were evaluated. We scored the degree of fat infiltration in each muscle by modified Mercuri score and performed hierarchical clustering analyses to classify the patients and infer the pattern of involvement on progression. Results All OPDM subtypes showed a similar pattern of distribution in the affected muscles; soleus and medial gastrocnemius involved in the early stage, followed by tibialis anterior and extensor digitorum longus. For differentiating OPDM and OPMD, severely affected gluteus medius/minimus and adductor magnus was indicative of OPMD. Discussion We identified a diagnostic muscle involvement pattern in OPDM reflecting its natural history. The results of this study will help in the appropriate intervention based on the diagnosis of OPDM, including its stage.