NadelEMG

Nadel-EMG, or needle electromyography, is an electrodiagnostic procedure used to assess the electrical activity of skeletal muscle and the integrity of the nerves that innervate it. By inserting fine needle electrodes into muscle tissue, it records spontaneous and voluntary motor unit activity, helping to define neuromuscular disorders.

The test is typically performed by neurologists or physiatrists trained in electrodiagnostic medicine. It is commonly performed alongside nerve conduction studies. A sterile, single-use needle electrode is inserted into several muscles across different regions, while the patient relaxes or gently contracts as instructed. Insertional activity is observed during needle placement, followed by recruitment patterns as the patient contracts.

Indications include evaluation of suspected radiculopathy, peripheral neuropathy, myopathy, motor neuron disease (such as ALS), inflammatory myopathies, and other neuromuscular conditions. It helps distinguish neuropathic from myopathic processes and can localize lesions along the motor unit.

Interpretation focuses on spontaneous activity at rest (fibrillations, positive sharp waves), insertional activity, and motor unit action potentials during contraction (amplitude, duration, polyphasia, recruitment). A neuropathic pattern shows reduced recruitment with large, long-duration MUAPs, whereas a myopathic pattern shows short-duration, small-amplitude MUAPs and early activation. Paraspinal muscles are examined to assess root-level disease.

Safety considerations include the risks of transient pain, bleeding, infection, or hematoma. The procedure uses sterile technique and single-use needles; contraindications include active skin infection at the insertion site or significant bleeding disorders. Discomfort varies and deep or multiple muscle samplings may be required; results depend on operator experience and patient cooperation. Ethical and regulatory guidelines govern its use.