Neuromuscular diseases (NMD) constitute a group of phenotypically and genetically heterogeneous disorders, characterized by (progressive) weakness and atrophy of proximal and/or distal muscles. The objective of molecular testing is to…
Electromyography and nerve conduction studies are the primary electrodiagnostic studies employed in the evaluation of patients with weakness and suspected myopathy. This article discusses the physiologic principles that serve as…
The rheumatologist is frequently called on to evaluate patients with complaints of myalgia, muscle cramps, and fatigue. The evaluation of these patients presents a diagnostic challenge given the nonspecific and…
Various diagnostic imaging techniques such as sonography, computed tomography, scintigraphy, radiography, and magnetic resonance imaging (MRI) have made possible the noninvasive evaluation of skeletal muscle injury and disease. Although these…
Chronic muscle weakness is a common complaint among patients seen in rheumatology and neuromuscular specialty clinics. This article focuses on adult-onset muscular dystrophies, select hereditary myopathies, and other neuromuscular conditions…
Many drugs can cause myopathies, and such myopathies may range widely from asymptomatic elevations in the serum creatine phosphokinase levels to severe myalgias, cramps, exercise intolerance, muscle weakness, and even…
In paraneoplastic muscle disease, the malignancy may remotely affect neuromuscular transmission or incite muscle inflammation or necrosis. In several of these diseases, an autoimmune basis for the muscle disease has…
Inclusion body myositis (IBM) is the most common acquired myopathy in people older than 50 years. IBM typically presents with distal upper extremity weakness accompanied by proximal lower extremity muscle…
Recent advances have increased the understanding of the pathogenesis of polymyositis and dermatomyositis. Clearly, the pathogenesis is complex, and adaptive (eg, autoimmune) and innate and nonimmune pathways play a role…
Idiopathic inflammatory myopathies are a heterogeneous group of autoimmune disorders predominantly affecting skeletal muscles, resulting in muscle inflammation and weakness. The 3 most common inflammatory myopathies are polymyositis (PM), dermatomyositis…
