Intramuscular dissociation of echogenicity in the triceps surae characterizes sporadic inclusion body myositis
Related Experiment Video
Updated: Mar 28, 2026
Author Spotlight: Exploring the Complexities of Achilles Tendon Injuries — Research and Future Directions
Published on: October 27, 2023
H Nodera1, N Takamatsu1,2, N Matsui1
1Department of Neurology, Tokushima University, Tokushima, Japan.
Background And Purpose:
Differential diagnosis of sporadic inclusion body myositis (s-IBM) and polymyositis (PM)/dermatomyositis (DM) is difficult and can affect proper disease management. Detection of heterogeneous muscular involvement in s-IBM by muscle sonography could be a unique diagnostic feature.
Methods:
Sonography of the lower leg and forearm was performed in patients with s-IBM, PM/DM and control subjects (n = 11 each). Echo intensities (EIs) of the adjacent muscles [medial head of the gastrocnemius versus soleus and the flexor digitorum profundus (FDP) versus flexor carpi ulnaris (FCU)] were scored by three blinded raters. The mean EIs of these muscles were compared using computer-assisted histogram analysis.
Results:
Both evaluation methods showed high echoic signals in the gastrocnemius of patients with s-IBM. EIs were significantly different between the gastrocnemius and soleus in patients with s-IBM, but not in those with DM/PM and the controls. In the forearm, although the EI of the FDP was higher in the s-IBM group than in the other groups, the EI differences between the FDP and FCU did not differ significantly between disease groups. The difference in area under the curves to differentiate between s-IBM and DM/PM was greatest between the gastrocnemius-soleus EIs (0.843; P = 0.006).
Conclusions:
High echoic signals in the medial gastrocnemius compared with those of the soleus are suggestive of s-IBM over PM/DM.
More Related Videos
08:12Author Spotlight: Isolation of Long Muscle Fibers from Mouse Hindlimb Muscles for Studying Excitation-Contraction Coupling Across Fiber Types
Published on: December 1, 2023
08:16Utility of Dissociated Intrinsic Hand Muscle Atrophy in the Diagnosis of Amyotrophic Lateral Sclerosis
Published on: March 4, 2014
Related Concept Videos
01:15Myasthenia Gravis: Diagnostic Tests
The edrophonium test is a diagnostic tool for myasthenia gravis. It involves...
01:28Disorders of the Skeletal Muscle
Musculoskeletal disorders
Musculoskeletal disorders involve injuries and conditions affecting the skeletal muscles and associated connective tissues. These disorders can arise from acute biomechanical stresses or chronic overuse and can occur across different age groups. Common injuries include sprains, fractures, and muscular strains, often resulting from...
01:27Myocarditis II: Clinical Features and Diagnostic Tests
01:13Microscopic Anatomy of Skeletal Muscles
The muscle sarcolemma is a plasma membrane enclosing each muscle cell that conducts electrical signals called action potentials. The sarcolemma extends into the cell to form T-tubules, ensuring the neural impulses are uniformly distributed across the entire muscle...
01:12Gross Anatomy of Skeletal Muscles
01:20Myasthenia Gravis: Overview and Treatment
These antibodies interfere with the function of the nicotinic receptors in three ways: by binding to the receptor and disrupting acetylcholine binding; by causing cross-linking of receptors which...