Electrodiagnostic

Electrodiagnostic medicine is the practice of using electrical testing to assess the function of the peripheral nervous system, muscles, and related pathways. It encompasses nerve conduction studies and electromyography, along with additional tests such as evoked potentials and autonomic testing in broader evaluations.

Nerve conduction studies involve delivering stimuli to a nerve with surface electrodes and recording the resulting responses from distal muscles or sensory nerves. Clinicians measure conduction velocity, latency, and amplitude to identify patterns of demyelination, axonal loss, or conduction block. Electromyography uses needle electrodes inserted into muscles to record electrical activity at rest and during contraction, helping to characterize neuromuscular disorders by evaluating motor unit potentials and spontaneous activity.

Other electrodiagnostic tests include evoked potentials, which assess the speed and integrity of sensory or cognitive pathways by recording responses to sensory stimuli, and autonomic tests that examine functions such as heart rate variability and skin conductance. In some practices, electroencephalography is included when brain activity assessment is relevant to the diagnostic question.

Safety and limitations: these tests are generally low risk, with common side effects limited to temporary discomfort from needle insertion. Rare complications can include infection or bleeding. Interpretation requires expertise and is influenced by patient factors and technique; abnormalities must be integrated with clinical history and imaging, as they are not definitive in isolation.

Practitioners typically include neurologists, physiatrists, and specialized neurodiagnostic technologists. Professional guidelines and credentialing are provided by organizations such as the American Association of Neuromuscular and Electrodiagnostic Medicine, which emphasize standardized techniques and quality interpretation.