What is electrodiagnosis in Physical Therapy (PT)?

From the Guidelines

Electrodiagnosis in physical therapy is a specialized assessment technique that uses electrical testing to evaluate neuromuscular function and diagnose various conditions affecting nerves and muscles, primarily involving procedures such as electromyography (EMG) and nerve conduction studies (NCS) 1.

Key Components of Electrodiagnosis

• Electromyography (EMG) records electrical activity in muscles
• Nerve conduction studies (NCS) measure how quickly and effectively nerves transmit electrical signals
• These tests help identify nerve injuries, muscle disorders, radiculopathies, peripheral neuropathies, and other neuromuscular conditions

Importance of Electrodiagnosis

• Helps develop targeted treatment plans by pinpointing the exact location and severity of nerve or muscle dysfunction
• Valuable for differentiating between conditions with similar symptoms, monitoring disease progression, and assessing treatment effectiveness
• Requires specialized training and certification beyond standard physical therapy education to ensure accurate interpretation of complex data 1

Recent Recommendations

• The 2022 American College of Rheumatology guideline conditionally recommends against the use of electrotherapy for rheumatoid arthritis management, based on low certainty evidence of no improvement in pain and physical function specific to RA 1

Considerations for Practice

• Physical therapists should consider the potential benefits and limitations of electrodiagnosis in their practice, including the need for specialized training and certification
• The use of electrotherapy modalities, such as transcutaneous electrical nerve stimulation (TENS) and neuro-muscular electrical nerve stimulation, should be approached with caution and considered on a case-by-case basis, given the conditional recommendation against their use in RA management 1

From the Research

Definition and Purpose of Electrodiagnosis in Physical Therapy

• Electrodiagnosis (EDX) is a diagnostic tool used to evaluate patients with neuromuscular disorders, providing important clues on location, chronicity, severity, and pathophysiology 2.
• It serves as an extension of a neurologic examination for evaluating a variety of focal and generalized neuromuscular conditions 2.
• The primary goal of electrodiagnosis is to help establish a diagnosis, evaluate the need for surgery, and assess patients who do not improve as expected after surgery 2.

Techniques and Tests Used in Electrodiagnosis

• Electrodiagnostic testing includes nerve conduction studies (NCS) and needle electrode examination (EMG) 2.
• Other tests used in electrodiagnosis include somatosensory evoked potentials, quantitative EMG, single fiber EMG, and autonomic testing 3.
• Nerve conduction studies provide an efficient and rapid method of quantifying nerve conduction velocity and the amplitude of both sensory nerve action potentials and compound motor action potentials 4.
• Electromyography (EMG) can detect myopathic changes in muscle and signs of denervation 4.

Applications and Interpretation of Electrodiagnosis

• Electrodiagnostic studies are used to diagnose and prognosticate nerve injuries, and are considered the gold standard for this purpose 5.
• The interpretation of electrodiagnostic studies requires a framework for understanding the relationship between demyelination, axon loss, Wallerian degeneration, nerve regeneration, collateral sprouting, and clinical function 5.
• Electrodiagnosis can help determine the distribution of nerve damage, whether it is generalized, multifocal, or focal, and can indicate if the primary target is the axon or the myelin sheath 4.
• The results of electrodiagnostic tests can be used to establish a diagnosis, evaluate the need for surgery, and assess patients who do not improve as expected after surgery 2.