[Inflammatory and other myopathies and skeletal muscle vasculitis: the role of muscle and nerve biopsy].

Muscle and nerve biopsies provide valuable information contributing to the diagnosis of diseases of the peripheral nervous system and skeletal muscle. The application of modern histological, immunohistochemical, electron microscopic and molecular methods establishes a definite diagnosis in many cases and narrows the spectrum of possible entities in most of the remaining cases. Inflammatory myopathies and neuropathies are distinguished from non-inflammatory muscular and peripheral nervous conditions. The latter include muscular dystrophies and congenital myopathies, hereditary neuropathies, metabolic diseases affecting skeletal muscle and peripheral nerves as well as degenerative myopathies and neuropathies including sporadic motor neuron diseases.