Department of Pathology, University of Oklahoma Health Sciences Center

NeuroTest Question #10 Next question Previous question

Answer: A (Z-disc streaming) Level of difficulty: 4 NeuroTest NeuroLearn NeuroHelp

Discussion: 

• Z-disc streaming: This is a classic picture of Z-disc streaming which is a very non-specific and common finding in myopathic muscles; it has also been observed in healthy controls. It is essentially disorganization of filaments. Z-disc str]eaming can involve many sarcomere units. The ones being shown here is, in fact, on the small side.
• Selective loss of thick filaments is typically seen in acute steroid myopathy (intensive care unit myoapthy). In this electron micrographj, well preserved light and heavy filaments are present at the peripheral of the picture. 
• Dystrophinopathies (Duchenne and Becker muscular dystrophy): There is no ultrastructural changes unique to them.
• Necrotic change and loss of thin filament: Thin filaments are preferentially lost at the early stage of necrosis. However, both thin and thick filaments are well preserved here.

Comment: KarMing-Fung@ouhsc.edu