Electrodiagnostic Reference Values in European Guidelines

Introduction to Electrodiagnostic Reference Values

The European Society of Cardiology recommends electrophysiological studies as Class I for patients with ischemic substrate and syncope, according to the European Society of Cardiology guidelines 1, 2
EULAR recommends nerve conduction studies to differentiate mononeuropathy from polyneuropathy and distinguish axonal from demyelinating neuropathies in lupus patients, as stated in the EULAR guidelines 3

Electrode type dramatically affects measurements, with monopolar electrodes having 1.5 times the uptake region of concentric electrodes, yielding different amplitude and duration values, as reported by the American Academy of Otolaryngology-Head and Neck Surgery 4
Age affects normal values, with MUAP durations doubling after age 60 years in thyroarytenoid muscles, according to the American Academy of Otolaryngology-Head and Neck Surgery 4
Muscle-specific variations exist, with normal laryngeal MUAPs showing mean durations of 4.5 ms and amplitudes of 350 microvolts in thyroarytenoid muscle versus 280 microvolts in cricothyroid muscle using concentric electrodes, as found by the American Academy of Otolaryngology-Head and Neck Surgery 4

Results are operator-dependent and require specialized training, as emphasized by the Centers for Disease Control and Prevention 5, 6, 7
Interpretation requires expert knowledge and must be contextualized with clinical findings, according to the Centers for Disease Control and Prevention 5, 6, 7

Ensure electrode type matches reference data (concentric vs. monopolar), as recommended by the American Academy of Otolaryngology-Head and Neck Surgery 4
Apply age-appropriate normative values when available, as suggested by the American Academy of Otolaryngology-Head and Neck Surgery 4
Compare results to contralateral limb or unaffected muscles when possible, as advised by the EULAR guidelines 3

Use consistent electrode types within your practice, as recommended by the American Academy of Otolaryngology-Head and Neck Surgery 4
Maintain consistent filter settings, as suggested by the American Academy of Otolaryngology-Head and Neck Surgery 4
Document patient age, as this significantly affects normal values, according to the American Academy of Otolaryngology-Head and Neck Surgery 4