Antidromic vs orthodromic sensory median nerve conduction studies

OBJECTIVE: Median sensory nerve conduction studies are arguably the most often performed electrodiagnostic tests worldwide. Routine tests in clinical practice are done using either antidromic or orthodromic techniques type of stimulation, with no universal agreement on the use of one or the other technique. METHODS: We review the advantages and drawbacks of antidromic and orthodromic as well as their particularities for clinical application and research. RESULTS: The two techniques differ on how physical and physiological changes affect the action potential. Near-nerve recording is better suited for the orthodromic than for the antidromic technique, while studies of nerve excitability are better suited for the antidromic than for the orthodromic technique. CONCLUSION: Both techniques are equally suitable for routine tests but research studies may specifically demand one or the other.