Abstract and Introduction
Muscle diseases constitute a large variety of both acquired and hereditary disorders that can affect muscle structure, metabolism, or the function of the muscle channel. A successful clinical approach to a patient with a suspected myopathy is based on a thorough medical history and neurological examination. Associated clinical symptoms such as myoglobinuria, contractures, myotonia, cardiac disease, and respiratory insufficiency can be extremely helpful in limiting the differential diagnosis. In addition, a phenotypic approach to diagnosis according to the patient's predominant pattern of weakness is essential for guiding the physician in selecting the most appropriate diagnostic studies. Although muscle biopsy remains a useful tool, molecular genetic studies are now available for the noninvasive diagnosis of many muscle diseases.
Muscle diseases are disorders in which there is a structural or functional abnormality of skeletal muscle. Muscle diseases can be distinguished from other disorders of the motor unit—including motor neuron diseases, neuromuscular junction disorders, and peripheral neuropathies—by characteristic clinical and laboratory features. The first goal, therefore, in approaching a patient with a suspected muscle disease is to identify the correct site of the lesion. The second goal is to determine whether the muscle disease is due to an acquired or a hereditary disorder to provide accurate genetic counseling. Finally, the third goal in our clinical approach is to determine if there is a specific treatment. Certainly in most hereditary muscle diseases, there is no curative therapy, and the clinician's focus must be on aggressive symptom management and the provision of appropriate adaptive equipment to maximize the patient's functional abilities and enhance quality of life.
Semin Neurol. 2008;28(2):228-240. © 2008 Thieme Medical Publishers
Cite this: Clinical Approach to Muscle Diseases - Medscape - Apr 01, 2008.