MUSCLE DISEASE

any of the diseases and disorders that affect the human muscle system. Diseases and disorders that result from direct abnormalities of the muscles are called primary muscle diseases; those that can be traced as symptoms or manifestations of disorders of nerves or other systems are not properly classified as primary muscle diseases. Because muscles and nerves (neurons) supplying muscle operate as a functional unit, disease of both systems results in muscular atrophy (wasting) and paralysis. Additional reading A comprehensive modern review of the myopathies will be found in John Walton (ed.), Disorders of Voluntary Muscle, 5th ed. (1988); this work also contains chapters on the anatomy and physiology of muscle. Michael H. Brooke, A Clinician's View of Neuromuscular Diseases, 2nd ed. (1986), is a good, brief review of muscle disease. Stirling Carpenter and George Karpati, Pathology of Skeletal Muscle (1984); and Andrew G. Engel and Betty Q. Banker, Myology: Basic and Clinical, 2 vol. (1986), are extensive treatments.