[Diagnostic value of muscle biopsy in neuromuscular diseases]

Aside from clinical electrophysiology, muscle biopsy is an important method regarding the diagnosis of neuromuscular diseases. Functional disturbances like myasthenia, myotonia, or paramyotonia only lead to slight and unspecific morphological alterations of the muscle tissue. In most cases, progressive muscular dystrophies, myotonic dystrophy, and myositis of various etiologies each have their own bioptic and electrophysiological characteristics. The diagnosis of these diseases should be confirmed by both methods. Some inflammatory diseases, such as panarteriitis nodosa and muscular sarcoidosis, may be diagnosed on account of histologic findings only. The same is true for rhabdomyolysis and congenital myopathies.