Electrodiagnostic evaluation of carpal tunnel syndrome (original) (raw)

Carpal tunnel syndrome (CTS) is the most common nerve entrapment. Electrodiagnostic (EDX) studies are a valid and reliable means of confirming the diagnosis. This monograph addresses the various EDX techniques used to evaluate the median nerve at the wrist. It also demonstrates the limitations of EDX studies with a focus on the sensitivity and specificity of EDX testing for CTS. The need to use reference values for populations such as diabetics and active workers, where normative values differ from conventional cutoffs used to confirm suspected CTS, is presented. The value of needle electromyography (EMG) is examined. 44: 597-607, 2011 Carpal tunnel syndrome (CTS) is a clinical syn-Abbreviations: AANEM, American Association of Neuromuscular and Electrodiagnostic Medicine; AAOS, American Academy of Orthopedic Surgeons; APB, abductor pollicis brevis; CMAP, compound muscle action potential; CSI, combined summary index; CTS, carpal tunnel syndrome; EDX, electrodiagnostic; EMG, electromyography; inching, median sensory short segment stimulation across the wrist; MGA, Martin-Gruber anastomosis; MMW, median mononeuropathy at the wrist; NAP, nerve action potential; NCS, nerve conduction studies; palmdiff, median-ulnar mixed nerve palm latency difference from palm to wrist; ringdiff, median-ulnar sensory latency difference to the ring finger; SNAP, sensory nerve action potential; thumbdiff, median-radial latency difference to the thumb