At–a–glance muscle histology of neuromuscular disorders

Abstract

For an accurate diagnosis of neuromuscular disorders, neurological examination based on intensive history taking is definitely important to figure out the distribution of muscle wasting and weakness, as well as accompanying findings including muscle pain, fasciculation, tremorous movement, myotonia, and dermatological changes. Moreover, further medical work–up, such as myogenic enzymes, myositis–specific and –associated autoantibodies, radiology, and electrophysiology, should be conducted to determine application of genetic and muscle histological examination. Muscle biopsy must be performed on adequate region for suspected diseases, and the samples must be collected and treated properly because the operation is invasive. We here focus on frequently encountered neuromuscular disorders for neurologists, and illustrate the cases that can be preferentially conducted muscle biopsy or genetic analysis with specific examples. We present representative histological features of inflammatory myopathies, muscular dystrophies, distal myopathies, neurogenic atrophies, and others. Comprehensive knowledge of muscle histological findings is essential for systematic diagnostic procedure for neuromuscular disorders.