Updates on Diagnostic Criteria of Inclusion Body Myositis

Inclusion body myositis (IBM) is a gradually progressing muscle disorder, which preferentially affects the deep finger flexors and knee extensors, usually in an asymmetric manner. However, the initial presentation in some patients may not fit this typical phenotype. Muscle histopathology is required to confirm the diagnosis of IBM, and the role of muscle MRI and anti-cytosolic 5'-nucleotidase 1A antibody in IBM has been increasingly recognized. Diagnostic criteria for IBM have evolved since 1995. The most recent 2024 European Neuromuscular Center diagnostic criteria aimed to improve sensitivity and incorporate new developments in the field of IBM.