A muscle biopsy is typically performed on an outpatient basis. The muscle biopsy is processed and examined under a microscope. Different tests are performed depending on the suspected diagnosis.
The processing may take at least one week or more. This is followed by detailed analysis leading to a full report, which may take up to three to four weeks. The result is sent to the referring doctor, who will then explain the findings to you. Any sample remaining after this analysis is stored in case further analysis or re-analysis is required in the future. Muscle biopsy Procedure Overview A muscle biopsy is a procedure used to diagnose diseases involving muscles.
Reasons for the Procedure A muscle biopsy is performed to assess the musculoskeletal system for abnormalities. There may be other reasons for your physician to recommend a muscle biopsy. Muscular dystrophy causes the muscles in the body to become very weak. The muscles break down and are replaced with fatty deposits over time. There are many different types of muscular dystrophies. Metabolic, toxic, mitochondrial myopathies These muscle disorders are due to specific enzyme defects, exposure to toxins including certain medications, and abnormalities of the mitochondria.
Polymyositis A disorder that causes inflammation of many of the skeletal muscles. Dermatomyositis A multisystem disorder that causes inflammation of the skin, muscles, and subcutaneous tissues often resulting in muscle weakness. Inclusion Body Myositis A chronic progressive disorder of the muscle also considered autoimmune in nature.
Neurogenic atrophy Disorders of the motor neurons and nerves cause muscle atrophy and sometime muscle biopsies are necessary for diagnosis and management. Risks of the Procedure As with any surgical procedure, complications can occur. Some possible complications may include, but are not limited to, the following: Bruising and discomfort at the biopsy site Bleeding from the biopsy site Infection of the biopsy site There may be other risks depending upon your specific medical condition.
Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Separating muscle fibers with suture before cutting the ends of the fiber. Figure 9. Table 1 The amount of tissue that is optimal for the required technique and immediate handling instructions for the biopsied tissue.
Rapid freezing in liquid nitrogen at site of biopsy. Ship frozen on dry ice over night. Figure Covering the wound with steri-strips, nonstick gauze and occlusive dressing. Needle Biopsy Needle biopsy instead of an open procedure can be performed and is the preferred method at some institutions. Shipping and handling The specimen should quickly be packaged for shipment to the pathology laboratory. Reference laboratories There are many academic and a few commercial laboratories which can provide good quality, basic muscle histology processing.
Interpreting muscle biopsy results Detailed interpretation of muscle histology is outside of the scope of this article, but we would like to convey a basic understanding of the common techniques and stains used when assessing muscle biopsy specimens.
Shows fiber type grouping and fiber type predominance. Table 3 Available immunohistochemical antibodies for muscle biopsy analysis Normal muscle structure and appearance Normal human muscle is composed of many individual muscle fibers bundled together by layers of connective tissue that are arranged in a nesting-doll like fashion. Skeletal muscle cells on HE showing striation and eccentrically located nucleii. Patterns of neuromuscular disease There are two major characteristic myopathologic patterns of neuromuscular disease: 1 neurogenic, resulting from diseases of the innervating neuron; and 2 myopathic, due to intrinsic diseases of the muscle fiber that can be inherited or acquired, including the muscular dystrophies, congenital, inflammatory, metabolic and toxic myopathies.
Myopathic Changes Myopathic changes observed on biopsy often include both a common underlying pattern of muscle disease with superimposed disease-specific structural alterations. Disease specific changes While most diseases of muscle have some or all of the above findings, a few will appear normal on muscle biopsy with only minimal hints of disease. Ragged red fiber shown in muscle stained with Gomori Trichrome. Oil-red-O stain revealing increased lipid storage in type I muscle fibers.
Table 4 Histopathologic features found in select muscular dystrophies. Table 9 Common histopathologic findings in select toxic myopathies. Conclusion Muscle biopsy is valuable diagnostic tool when faced with the challenge of assessing a patient with weakness due to an underlying neuromuscular disease.
Table 6 Common histopathologic findings in select glycogen storage metabolic myopathies. Table 7 Common histopathologic findings in select lipid storage and mitochondrial myopathies. Table 8 Common histopathologic findings in select inflammatory myopathies.
Key points. Acknowledgments Dr. Footnotes Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. References 1. Dubowitz V, Sewry C. The procedure of muscle biopsy in Muscle Biospy a practical approach. Saunders Elsevier; Muscle MRI in inherited neuromuscular disorders: past, present, and future. J Magn Reson Imaging. Muscle imaging in clinical practice: diagnostic value of muscle magnetic resonance imaging in inherited neuromuscular disorders.
Curr Opin Neurol. Calibrated quantitative ultrasound imaging of skeletal muscle using backscatter analysis. Muscle Nerve. Fiber type composition of the vastus lateralis muscle of young men and women. J Histochem Cytochem. Schiaffino S, Reggiani C. Fiber types in mammalian skeletal muscles. Physiol Rev. Open muscle biopsy in suspected myopathy: diagnostic yield and clinical utility. Eur J Neurol. Epub Aug 5. Metabolic Myopathies in Major problems in neurology.
Saunders Ltd. Muscle biopsy. J Neurol. Routinely frozen biopsies of human skeletal muscle are suitable for morphological and immunocytochemical analyses at transmission electron microscopy.
Eur J Histochem. Exeter D, Connell DA. Skeletal muscle: functional anatomy and pathophysiology. Semin Musculoskelet Radiol. In: Disease of skeletal muscle within Neuropathology: The diagnostic approach.
Garcia Julie. Mosby St. Louis; Bossen E. Wortmann Robert. Lippincott Williams and Wilkins; Philadelphia: Human skeletal muscle fiber type classifications.
Phys Ther. WB Saunders Co. In: Disease of skeletal muscle in Neuropathology: The diagnostic approach. Garcia Julia. Muscle histopathology in upper motor neuron-dominant amyotrophic lateral sclerosis. Amyotroph Lateral Scler. Schmitt HP, Volk B. Buxton PH. Pathology of muscle. Br J Anaesth. Dalakas MC. Muscle biopsy findings in inflammatory myopathies. Rheum Dis Clin North Am. Toxic myopathies: muscle biopsy features.
Arq Neuropsiquiatr. Type I fiber atrophy and internal nuclei. A form of centronuclear myopathy? Arch Neurol. Clinical and histologic findings in autosomal centronuclear myopathy. Preferential central nucleation of type 2 myofibers is an invariable feature of myotonic dystrophy type 2. William N. Fishbein Myoadenylate deaminase deficiency: Inherited and acquired forms. Biochem Med. Ragged red fibers in normal aging and inflammatory myopathy. Ann Neurol. Core myopathies.
Semin Pediatr Neurol. Huizing M, Krasnewich DM. Hereditary inclusion body myopathy: a decade of progress. Biochim Biophys Acta. Support Center Support Center. External link. Please review our privacy policy. Muscle protein abnormalities detectable by immunohistochemical analysis. Muscle fiber morphology and enzyme histochemistry Most diagnostic information with light microscopy. Wrap in lightly moist gauze and ship to processing laboratory. Ultrastructural analysis Visualization of endomysial capillaries, inclusions, mitochondria, myofilaments, collagen, etc.
General morphology including fiber size, split fibers, location of nucleii, regenerating and degenerating fibers, connective tissue, inflammatory cells, inclusions and storage material,. Mitochondrial abnormalities, inclusion bodies, nemalin rods, and connective tissue. Adenosine triphosphatase ATPase pH 9.
Performed at different pH's to visualize different fiber types. Intracellular structures and myofibrillar organization. Increased perimyseal staining in inflammatory myopathies. Merosin deficient congenital muscular dystrophy.
Myopathic pattern with breaks in the sarcolemma Necrosis myophagocytosis. A chronic disease involving skeletal muscles.
A collagen disorder that causes inflammation to the skin, muscles, and subcutaneous tissue, often resulting in weakened muscles. Amyotrophic lateral sclerosis ALS. Also known as Lou Gehrig disease, ALS is a disease that attacks the nerves signaling voluntary muscle movement, eventually causing paralysis. Friedreich ataxia. An inherited, genetic disorder that involves balance and coordination. There may be other reasons for your healthcare provider to recommend a muscle biopsy.
What are the risks of a muscle biopsy? Some possible complications may include: Bruising and discomfort at the biopsy site Prolonged bleeding from the biopsy site Infection of the biopsy site Other risks may exist, depending on your specific medical condition. How do I get ready for a muscle biopsy?
Your healthcare provider will explain the procedure to you and you can ask any questions you may have. You will be asked to sign a consent form that gives your permission to do the procedure. Read the form carefully and ask questions if something is not clear. In addition to a complete medical history, your healthcare provider may do a complete physical exam to ensure you are in otherwise good health before undergoing the procedure. You may have blood tests or other diagnostic tests.
Tell your healthcare provider if you are sensitive or allergic to any medicines, latex, tape, or anesthetic agents local and general. Tell your healthcare provider of all medicines prescribed and over-the-counter and herbal supplements that you take. Tell your provider if you have a history of bleeding disorders, or if you take any anticoagulant blood-thinning medicines, aspirin, or other medicines that affect blood clotting.
You may need to stop these medicines before the procedure. If you are pregnant or think you could be, tell your healthcare provider.
You may be asked to fast for several hours before the procedure. You may receive a sedative before the procedure to help you relax. Because the sedative may make you drowsy, you will need to arrange for someone to drive you home. Based on your medical condition, your healthcare provider may request other specific preparation. What happens during a muscle biopsy? Generally, a muscle biopsy follows this process: You will be asked to remove clothing and will be given a gown to wear.
During the procedure, you will need to lie as still as possible. A healthcare provider will clean the skin over the biopsy site with an antiseptic solution.
As your healthcare provider injects a local anesthetic to numb the area, you will feel a needle stick and a brief stinging sensation. Your healthcare provider will insert the biopsy needle through your numbed skin and into the muscle to take the sample.
0コメント