Myopathy (Muscle Disease)
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What is Myopathy?
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Myopathy is a general term for disorders that affect the muscles themselves rather than the nerves supplying them.
There are many possible causes, including:
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Inherited muscle disorders (muscular dystrophies)
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Inflammatory muscle diseases (myositis)
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Medication-related muscle problems (for example, statins)
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Hormonal disorders such as thyroid disease
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Metabolic and mitochondrial disorders
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Symptoms may include:
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Muscle weakness, particularly in the shoulders and hips
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Difficulty climbing stairs or rising from a chair
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Trouble lifting objects overhead
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Muscle pain or cramps
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Fatigue
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Episodes of raised creatine kinase (CK)
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Why Have I Been Referred for Nerve Conduction Studies (NCS) and Electromyography (EMG)?
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Your doctor may have recommended these tests to:
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Determine whether your symptoms are due to a muscle disorder rather than a nerve problem
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Identify the pattern of muscle involvement
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Help distinguish between inherited, inflammatory, and other types of myopathy
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Guide further investigations such as blood tests, genetic testing, MRI, or muscle biopsy
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Monitor disease progression in selected cases
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These tests provide important functional information that complements blood tests and imaging.
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What to Expect During the Test
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Nerve Conduction Studies (NCS): These are often performed first to exclude neuropathy or neuromuscular junction disorders. Results may be normal in many muscle disorders.
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Electromyography (EMG): EMG is the key part of the assessment. A very fine, disposable sterile needle is inserted into selected muscles to analyse their electrical activity. Characteristic findings can suggest a muscle disorder and help identify the most appropriate next investigations.
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For further information on NCS/EMG, please visit our information page here.
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Summary
Myopathy refers to conditions that directly affect the muscles and can lead to weakness, fatigue, and difficulty with everyday activities. NCS and EMG are safe, specialised tests that help determine whether the problem lies in the muscles, nerves, or neuromuscular junction. The results guide further investigations and treatment tailored to the underlying cause.