Clinical characteristics of dysphagic inclusion body myositis

This study aimed to characterize dysphagic patients with inclusion body myositis (IBM) with cricopharyngeal bar (CPB) (n = 17; IBM-CPB(+)) by comparing their swallowing function and muscle magnetic resonance imaging data with IBM patients without CPB (n = 28; IBM-CPB(-)). IBM-CPB(+) patients were older at diagnosis and had more frequent obstruction-related dysphagia and stronger knee extension than IBM-CPB(-) patients. IBM-CPB(+) patients also had less intramuscular fatty infiltration than IBM-CPB(-) patients on T1-weighted magnetic resonance images of the rectus femoris (2.6% versus 10.3%, p < 0.05), vastus lateralis (27.8% versus 57.1%, p < 0.01), vastus intermedius (17.6% versus 43.5%, p < 0.01), vastus medialis (14.1% versus 39.1%, p < 0.01), deltoid (5.5% versus 18.7%, p < 0.05), biceps (6.6% versus 21.1%, p < 0.001), and triceps (12.9% versus 33.0%, p < 0.05). These findings suggest that IBM-CPB(+) patients were older, frequently exhibited obstruction-related dysphagia, had stronger knee extension, and had less fatty infiltration of the limb muscles compared to IBM-CPB(-) patients, and provide valuable information on the clinical subset of IBM-CBP(+) patients in order to expand the knowledge of the clinical heterogeneity in IBM.